text: // Copyright 2012 the V8 project authors. All rights reserved.
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  //       notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  //       copyright notice, this list of conditions and the following
  //       disclaimer in the documentation and/or other materials provided
  //       with the distribution.
  //     * Neither the name of Google Inc. nor the names of its
  //       contributors may be used to endorse or promote products derived
  //       from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #include "v8.h"
  
  #include "arm/lithium-codegen-arm.h"
  #include "arm/lithium-gap-resolver-arm.h"
  #include "code-stubs.h"
  #include "stub-cache.h"
  
  namespace v8 {
  namespace internal {
  
  
  class SafepointGenerator : public CallWrapper {
   public:
    SafepointGenerator(LCodeGen* codegen,
                       LPointerMap* pointers,
                       Safepoint::DeoptMode mode)
        : codegen_(codegen),
          pointers_(pointers),
          deopt_mode_(mode) { }
    virtual ~SafepointGenerator() { }
  
    virtual void BeforeCall(int call_size) const { }
  
    virtual void AfterCall() const {
      codegen_->RecordSafepoint(pointers_, deopt_mode_);
    }
  
   private:
    LCodeGen* codegen_;
    LPointerMap* pointers_;
    Safepoint::DeoptMode deopt_mode_;
  };
  
  
  #define __ masm()->
  
  bool LCodeGen::GenerateCode() {
    HPhase phase("Z_Code generation", chunk());
    ASSERT(is_unused());
    status_ = GENERATING;
    CpuFeatures::Scope scope1(VFP3);
    CpuFeatures::Scope scope2(ARMv7);
  
    CodeStub::GenerateFPStubs();
  
    // Open a frame scope to indicate that there is a frame on the stack.  The
    // NONE indicates that the scope shouldn't actually generate code to set up
    // the frame (that is done in GeneratePrologue).
    FrameScope frame_scope(masm_, StackFrame::NONE);
  
    return GeneratePrologue() &&
        GenerateBody() &&
        GenerateDeferredCode() &&
        GenerateDeoptJumpTable() &&
        GenerateSafepointTable();
  }
  
  
  void LCodeGen::FinishCode(Handle<Code> code) {
    ASSERT(is_done());
    code->set_stack_slots(GetStackSlotCount());
    code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
    PopulateDeoptimizationData(code);
  }
  
  
  void LCodeGen::Abort(const char* format, ...) {
    if (FLAG_trace_bailout) {
      SmartArrayPointer<char> name(
          info()->shared_info()->DebugName()->ToCString());
      PrintF("Aborting LCodeGen in @\"%s\": ", *name);
      va_list arguments;
      va_start(arguments, format);
      OS::VPrint(format, arguments);
      va_end(arguments);
      PrintF("\n");
    }
    status_ = ABORTED;
  }
  
  
  void LCodeGen::Comment(const char* format, ...) {
    if (!FLAG_code_comments) return;
    char buffer[4 * KB];
    StringBuilder builder(buffer, ARRAY_SIZE(buffer));
    va_list arguments;
    va_start(arguments, format);
    builder.AddFormattedList(format, arguments);
    va_end(arguments);
  
    // Copy the string before recording it in the assembler to avoid
    // issues when the stack allocated buffer goes out of scope.
    size_t length = builder.position();
    Vector<char> copy = Vector<char>::New(length + 1);
    memcpy(copy.start(), builder.Finalize(), copy.length());
    masm()->RecordComment(copy.start());
  }
  
  
  bool LCodeGen::GeneratePrologue() {
    ASSERT(is_generating());
  
  #ifdef DEBUG
    if (strlen(FLAG_stop_at) > 0 &&
        info_->function()->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
      __ stop("stop_at");
    }
  #endif
  
    // r1: Callee's JS function.
    // cp: Callee's context.
    // fp: Caller's frame pointer.
    // lr: Caller's pc.
  
    // Strict mode functions and builtins need to replace the receiver
    // with undefined when called as functions (without an explicit
    // receiver object). r5 is zero for method calls and non-zero for
    // function calls.
    if (!info_->is_classic_mode() || info_->is_native()) {
      Label ok;
      __ cmp(r5, Operand(0));
      __ b(eq, &ok);
      int receiver_offset = scope()->num_parameters() * kPointerSize;
      __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
      __ str(r2, MemOperand(sp, receiver_offset));
      __ bind(&ok);
    }
  
    __ stm(db_w, sp, r1.bit() | cp.bit() | fp.bit() | lr.bit());
    __ add(fp, sp, Operand(2 * kPointerSize));  // Adjust FP to point to saved FP.
  
    // Reserve space for the stack slots needed by the code.
    int slots = GetStackSlotCount();
    if (slots > 0) {
      if (FLAG_debug_code) {
        __ mov(r0, Operand(slots));
        __ mov(r2, Operand(kSlotsZapValue));
        Label loop;
        __ bind(&loop);
        __ push(r2);
        __ sub(r0, r0, Operand(1), SetCC);
        __ b(ne, &loop);
      } else {
        __ sub(sp,  sp, Operand(slots * kPointerSize));
      }
    }
  
    // Possibly allocate a local context.
    int heap_slots = scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
    if (heap_slots > 0) {
      Comment(";;; Allocate local context");
      // Argument to NewContext is the function, which is in r1.
      __ push(r1);
      if (heap_slots <= FastNewContextStub::kMaximumSlots) {
        FastNewContextStub stub(heap_slots);
        __ CallStub(&stub);
      } else {
        __ CallRuntime(Runtime::kNewFunctionContext, 1);
      }
      RecordSafepoint(Safepoint::kNoLazyDeopt);
      // Context is returned in both r0 and cp.  It replaces the context
      // passed to us.  It's saved in the stack and kept live in cp.
      __ str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
      // Copy any necessary parameters into the context.
      int num_parameters = scope()->num_parameters();
      for (int i = 0; i < num_parameters; i++) {
        Variable* var = scope()->parameter(i);
        if (var->IsContextSlot()) {
          int parameter_offset = StandardFrameConstants::kCallerSPOffset +
              (num_parameters - 1 - i) * kPointerSize;
          // Load parameter from stack.
          __ ldr(r0, MemOperand(fp, parameter_offset));
          // Store it in the context.
          MemOperand target = ContextOperand(cp, var->index());
          __ str(r0, target);
          // Update the write barrier. This clobbers r3 and r0.
          __ RecordWriteContextSlot(
              cp, target.offset(), r0, r3, kLRHasBeenSaved, kSaveFPRegs);
        }
      }
      Comment(";;; End allocate local context");
    }
  
    // Trace the call.
    if (FLAG_trace) {
      __ CallRuntime(Runtime::kTraceEnter, 0);
    }
    return !is_aborted();
  }
  
  
  bool LCodeGen::GenerateBody() {
    ASSERT(is_generating());
    bool emit_instructions = true;
    for (current_instruction_ = 0;
         !is_aborted() && current_instruction_ < instructions_->length();
         current_instruction_++) {
      LInstruction* instr = instructions_->at(current_instruction_);
      if (instr->IsLabel()) {
        LLabel* label = LLabel::cast(instr);
        emit_instructions = !label->HasReplacement();
      }
  
      if (emit_instructions) {
        Comment(";;; @%d: %s.", current_instruction_, instr->Mnemonic());
        instr->CompileToNative(this);
      }
    }
    EnsureSpaceForLazyDeopt();
    return !is_aborted();
  }
  
  
  bool LCodeGen::GenerateDeferredCode() {
    ASSERT(is_generating());
    if (deferred_.length() > 0) {
      for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
        LDeferredCode* code = deferred_[i];
        __ bind(code->entry());
        Comment(";;; Deferred code @%d: %s.",
                code->instruction_index(),
                code->instr()->Mnemonic());
        code->Generate();
        __ jmp(code->exit());
      }
    }
  
    // Force constant pool emission at the end of the deferred code to make
    // sure that no constant pools are emitted after.
    masm()->CheckConstPool(true, false);
  
    return !is_aborted();
  }
  
  
  bool LCodeGen::GenerateDeoptJumpTable() {
    // Check that the jump table is accessible from everywhere in the function
    // code, i.e. that offsets to the table can be encoded in the 24bit signed
    // immediate of a branch instruction.
    // To simplify we consider the code size from the first instruction to the
    // end of the jump table. We also don't consider the pc load delta.
    // Each entry in the jump table generates one instruction and inlines one
    // 32bit data after it.
    if (!is_int24((masm()->pc_offset() / Assembler::kInstrSize) +
        deopt_jump_table_.length() * 2)) {
      Abort("Generated code is too large");
    }
  
    // Block the constant pool emission during the jump table emission.
    __ BlockConstPoolFor(deopt_jump_table_.length());
    __ RecordComment("[ Deoptimisation jump table");
    Label table_start;
    __ bind(&table_start);
    for (int i = 0; i < deopt_jump_table_.length(); i++) {
      __ bind(&deopt_jump_table_[i].label);
      __ ldr(pc, MemOperand(pc, Assembler::kInstrSize - Assembler::kPcLoadDelta));
      __ dd(reinterpret_cast<uint32_t>(deopt_jump_table_[i].address));
    }
    ASSERT(masm()->InstructionsGeneratedSince(&table_start) ==
        deopt_jump_table_.length() * 2);
    __ RecordComment("]");
  
    // 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() {
    ASSERT(is_done());
    safepoints_.Emit(masm(), GetStackSlotCount());
    return !is_aborted();
  }
  
  
  Register LCodeGen::ToRegister(int index) const {
    return Register::FromAllocationIndex(index);
  }
  
  
  DoubleRegister LCodeGen::ToDoubleRegister(int index) const {
    return DoubleRegister::FromAllocationIndex(index);
  }
  
  
  Register LCodeGen::ToRegister(LOperand* op) const {
    ASSERT(op->IsRegister());
    return ToRegister(op->index());
  }
  
  
  Register LCodeGen::EmitLoadRegister(LOperand* op, Register scratch) {
    if (op->IsRegister()) {
      return ToRegister(op->index());
    } else if (op->IsConstantOperand()) {
      LConstantOperand* const_op = LConstantOperand::cast(op);
      Handle<Object> literal = chunk_->LookupLiteral(const_op);
      Representation r = chunk_->LookupLiteralRepresentation(const_op);
      if (r.IsInteger32()) {
        ASSERT(literal->IsNumber());
        __ mov(scratch, Operand(static_cast<int32_t>(literal->Number())));
      } else if (r.IsDouble()) {
        Abort("EmitLoadRegister: Unsupported double immediate.");
      } else {
        ASSERT(r.IsTagged());
        if (literal->IsSmi()) {
          __ mov(scratch, Operand(literal));
        } else {
         __ LoadHeapObject(scratch, Handle<HeapObject>::cast(literal));
        }
      }
      return scratch;
    } else if (op->IsStackSlot() || op->IsArgument()) {
      __ ldr(scratch, ToMemOperand(op));
      return scratch;
    }
    UNREACHABLE();
    return scratch;
  }
  
  
  DoubleRegister LCodeGen::ToDoubleRegister(LOperand* op) const {
    ASSERT(op->IsDoubleRegister());
    return ToDoubleRegister(op->index());
  }
  
  
  DoubleRegister LCodeGen::EmitLoadDoubleRegister(LOperand* op,
                                                  SwVfpRegister flt_scratch,
                                                  DoubleRegister dbl_scratch) {
    if (op->IsDoubleRegister()) {
      return ToDoubleRegister(op->index());
    } else if (op->IsConstantOperand()) {
      LConstantOperand* const_op = LConstantOperand::cast(op);
      Handle<Object> literal = chunk_->LookupLiteral(const_op);
      Representation r = chunk_->LookupLiteralRepresentation(const_op);
      if (r.IsInteger32()) {
        ASSERT(literal->IsNumber());
        __ mov(ip, Operand(static_cast<int32_t>(literal->Number())));
        __ vmov(flt_scratch, ip);
        __ vcvt_f64_s32(dbl_scratch, flt_scratch);
        return dbl_scratch;
      } else if (r.IsDouble()) {
        Abort("unsupported double immediate");
      } else if (r.IsTagged()) {
        Abort("unsupported tagged immediate");
      }
    } else if (op->IsStackSlot() || op->IsArgument()) {
      // TODO(regis): Why is vldr not taking a MemOperand?
      // __ vldr(dbl_scratch, ToMemOperand(op));
      MemOperand mem_op = ToMemOperand(op);
      __ vldr(dbl_scratch, mem_op.rn(), mem_op.offset());
      return dbl_scratch;
    }
    UNREACHABLE();
    return dbl_scratch;
  }
  
  
  Handle<Object> LCodeGen::ToHandle(LConstantOperand* op) const {
    Handle<Object> literal = chunk_->LookupLiteral(op);
    ASSERT(chunk_->LookupLiteralRepresentation(op).IsTagged());
    return literal;
  }
  
  
  bool LCodeGen::IsInteger32(LConstantOperand* op) const {
    return chunk_->LookupLiteralRepresentation(op).IsInteger32();
  }
  
  
  int LCodeGen::ToInteger32(LConstantOperand* op) const {
    Handle<Object> value = chunk_->LookupLiteral(op);
    ASSERT(chunk_->LookupLiteralRepresentation(op).IsInteger32());
    ASSERT(static_cast<double>(static_cast<int32_t>(value->Number())) ==
        value->Number());
    return static_cast<int32_t>(value->Number());
  }
  
  
  double LCodeGen::ToDouble(LConstantOperand* op) const {
    Handle<Object> value = chunk_->LookupLiteral(op);
    return value->Number();
  }
  
  
  Operand LCodeGen::ToOperand(LOperand* op) {
    if (op->IsConstantOperand()) {
      LConstantOperand* const_op = LConstantOperand::cast(op);
      Handle<Object> literal = chunk_->LookupLiteral(const_op);
      Representation r = chunk_->LookupLiteralRepresentation(const_op);
      if (r.IsInteger32()) {
        ASSERT(literal->IsNumber());
        return Operand(static_cast<int32_t>(literal->Number()));
      } else if (r.IsDouble()) {
        Abort("ToOperand Unsupported double immediate.");
      }
      ASSERT(r.IsTagged());
      return Operand(literal);
    } else if (op->IsRegister()) {
      return Operand(ToRegister(op));
    } else if (op->IsDoubleRegister()) {
      Abort("ToOperand IsDoubleRegister unimplemented");
      return Operand(0);
    }
    // Stack slots not implemented, use ToMemOperand instead.
    UNREACHABLE();
    return Operand(0);
  }
  
  
  MemOperand LCodeGen::ToMemOperand(LOperand* op) const {
    ASSERT(!op->IsRegister());
    ASSERT(!op->IsDoubleRegister());
    ASSERT(op->IsStackSlot() || op->IsDoubleStackSlot());
    int index = op->index();
    if (index >= 0) {
      // Local or spill slot. Skip the frame pointer, function, and
      // context in the fixed part of the frame.
      return MemOperand(fp, -(index + 3) * kPointerSize);
    } else {
      // Incoming parameter. Skip the return address.
      return MemOperand(fp, -(index - 1) * kPointerSize);
    }
  }
  
  
  MemOperand LCodeGen::ToHighMemOperand(LOperand* op) const {
    ASSERT(op->IsDoubleStackSlot());
    int index = op->index();
    if (index >= 0) {
      // Local or spill slot. Skip the frame pointer, function, context,
      // and the first word of the double in the fixed part of the frame.
      return MemOperand(fp, -(index + 3) * kPointerSize + kPointerSize);
    } else {
      // Incoming parameter. Skip the return address and the first word of
      // the double.
      return MemOperand(fp, -(index - 1) * kPointerSize + kPointerSize);
    }
  }
  
  
  void LCodeGen::WriteTranslation(LEnvironment* environment,
                                  Translation* translation) {
    if (environment == NULL) return;
  
    // The translation includes one command per value in the environment.
    int translation_size = environment->values()->length();
    // The output frame height does not include the parameters.
    int height = translation_size - environment->parameter_count();
  
    WriteTranslation(environment->outer(), translation);
    int closure_id = DefineDeoptimizationLiteral(environment->closure());
    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 ARGUMENTS_ADAPTOR:
        translation->BeginArgumentsAdaptorFrame(closure_id, translation_size);
        break;
      default:
        UNREACHABLE();
    }
    for (int i = 0; i < translation_size; ++i) {
      LOperand* value = environment->values()->at(i);
      // spilled_registers_ and spilled_double_registers_ are either
      // both NULL or both set.
      if (environment->spilled_registers() != NULL && value != NULL) {
        if (value->IsRegister() &&
            environment->spilled_registers()[value->index()] != NULL) {
          translation->MarkDuplicate();
          AddToTranslation(translation,
                           environment->spilled_registers()[value->index()],
                           environment->HasTaggedValueAt(i));
        } else if (
            value->IsDoubleRegister() &&
            environment->spilled_double_registers()[value->index()] != NULL) {
          translation->MarkDuplicate();
          AddToTranslation(
              translation,
              environment->spilled_double_registers()[value->index()],
              false);
        }
      }
  
      AddToTranslation(translation, value, environment->HasTaggedValueAt(i));
    }
  }
  
  
  void LCodeGen::AddToTranslation(Translation* translation,
                                  LOperand* op,
                                  bool is_tagged) {
    if (op == NULL) {
      // TODO(twuerthinger): Introduce marker operands to indicate that this value
      // is not present and must be reconstructed from the deoptimizer. Currently
      // this is only used for the arguments object.
      translation->StoreArgumentsObject();
    } else if (op->IsStackSlot()) {
      if (is_tagged) {
        translation->StoreStackSlot(op->index());
      } else {
        translation->StoreInt32StackSlot(op->index());
      }
    } else if (op->IsDoubleStackSlot()) {
      translation->StoreDoubleStackSlot(op->index());
    } else if (op->IsArgument()) {
      ASSERT(is_tagged);
      int src_index = GetStackSlotCount() + op->index();
      translation->StoreStackSlot(src_index);
    } else if (op->IsRegister()) {
      Register reg = ToRegister(op);
      if (is_tagged) {
        translation->StoreRegister(reg);
      } else {
        translation->StoreInt32Register(reg);
      }
    } else if (op->IsDoubleRegister()) {
      DoubleRegister reg = ToDoubleRegister(op);
      translation->StoreDoubleRegister(reg);
    } else if (op->IsConstantOperand()) {
      Handle<Object> literal = chunk()->LookupLiteral(LConstantOperand::cast(op));
      int src_index = DefineDeoptimizationLiteral(literal);
      translation->StoreLiteral(src_index);
    } else {
      UNREACHABLE();
    }
  }
  
  
  void LCodeGen::CallCode(Handle<Code> code,
                          RelocInfo::Mode mode,
                          LInstruction* instr) {
    CallCodeGeneric(code, mode, instr, RECORD_SIMPLE_SAFEPOINT);
  }
  
  
  void LCodeGen::CallCodeGeneric(Handle<Code> code,
                                 RelocInfo::Mode mode,
                                 LInstruction* instr,
                                 SafepointMode safepoint_mode) {
    ASSERT(instr != NULL);
    LPointerMap* pointers = instr->pointer_map();
    RecordPosition(pointers->position());
    __ Call(code, mode);
    RecordSafepointWithLazyDeopt(instr, safepoint_mode);
  
    // Signal that we don't inline smi code before these stubs in the
    // optimizing code generator.
    if (code->kind() == Code::BINARY_OP_IC ||
        code->kind() == Code::COMPARE_IC) {
      __ nop();
    }
  }
  
  
  void LCodeGen::CallRuntime(const Runtime::Function* function,
                             int num_arguments,
                             LInstruction* instr) {
    ASSERT(instr != NULL);
    LPointerMap* pointers = instr->pointer_map();
    ASSERT(pointers != NULL);
    RecordPosition(pointers->position());
  
    __ CallRuntime(function, num_arguments);
    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
  }
  
  
  void LCodeGen::CallRuntimeFromDeferred(Runtime::FunctionId id,
                                         int argc,
                                         LInstruction* instr) {
    __ CallRuntimeSaveDoubles(id);
    RecordSafepointWithRegisters(
        instr->pointer_map(), argc, Safepoint::kNoLazyDeopt);
  }
  
  
  void LCodeGen::RegisterEnvironmentForDeoptimization(LEnvironment* environment,
                                                      Safepoint::DeoptMode mode) {
    if (!environment->HasBeenRegistered()) {
      // Physical stack frame layout:
      // -x ............. -4  0 ..................................... y
      // [incoming arguments] [spill slots] [pushed outgoing arguments]
  
      // Layout of the environment:
      // 0 ..................................................... size-1
      // [parameters] [locals] [expression stack including arguments]
  
      // Layout of the translation:
      // 0 ........................................................ size - 1 + 4
      // [expression stack including arguments] [locals] [4 words] [parameters]
      // |>------------  translation_size ------------<|
  
      int frame_count = 0;
      int jsframe_count = 0;
      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);
      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);
    }
  }
  
  
  void LCodeGen::DeoptimizeIf(Condition cc, LEnvironment* environment) {
    RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
    ASSERT(environment->HasBeenRegistered());
    int id = environment->deoptimization_index();
    Address entry = Deoptimizer::GetDeoptimizationEntry(id, Deoptimizer::EAGER);
    if (entry == NULL) {
      Abort("bailout was not prepared");
      return;
    }
  
    ASSERT(FLAG_deopt_every_n_times < 2);  // Other values not supported on ARM.
  
    if (FLAG_deopt_every_n_times == 1 &&
        info_->shared_info()->opt_count() == id) {
      __ Jump(entry, RelocInfo::RUNTIME_ENTRY);
      return;
    }
  
    if (FLAG_trap_on_deopt) __ stop("trap_on_deopt", cc);
  
    if (cc == al) {
      __ Jump(entry, RelocInfo::RUNTIME_ENTRY);
    } else {
      // We often have several deopts to the same entry, reuse the last
      // jump entry if this is the case.
      if (deopt_jump_table_.is_empty() ||
          (deopt_jump_table_.last().address != entry)) {
        deopt_jump_table_.Add(JumpTableEntry(entry));
      }
      __ b(cc, &deopt_jump_table_.last().label);
    }
  }
  
  
  void LCodeGen::PopulateDeoptimizationData(Handle<Code> code) {
    int length = deoptimizations_.length();
    if (length == 0) return;
    Handle<DeoptimizationInputData> data =
        factory()->NewDeoptimizationInputData(length, TENURED);
  
    Handle<ByteArray> translations = translations_.CreateByteArray();
    data->SetTranslationByteArray(*translations);
    data->SetInlinedFunctionCount(Smi::FromInt(inlined_function_count_));
  
    Handle<FixedArray> literals =
        factory()->NewFixedArray(deoptimization_literals_.length(), TENURED);
    for (int i = 0; i < deoptimization_literals_.length(); i++) {
      literals->set(i, *deoptimization_literals_[i]);
    }
    data->SetLiteralArray(*literals);
  
    data->SetOsrAstId(Smi::FromInt(info_->osr_ast_id()));
    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, Smi::FromInt(env->ast_id()));
      data->SetTranslationIndex(i, Smi::FromInt(env->translation_index()));
      data->SetArgumentsStackHeight(i,
                                    Smi::FromInt(env->arguments_stack_height()));
      data->SetPc(i, Smi::FromInt(env->pc_offset()));
    }
    code->set_deoptimization_data(*data);
  }
  
  
  int LCodeGen::DefineDeoptimizationLiteral(Handle<Object> literal) {
    int result = deoptimization_literals_.length();
    for (int i = 0; i < deoptimization_literals_.length(); ++i) {
      if (deoptimization_literals_[i].is_identical_to(literal)) return i;
    }
    deoptimization_literals_.Add(literal);
    return result;
  }
  
  
  void LCodeGen::PopulateDeoptimizationLiteralsWithInlinedFunctions() {
    ASSERT(deoptimization_literals_.length() == 0);
  
    const ZoneList<Handle<JSFunction> >* inlined_closures =
        chunk()->inlined_closures();
  
    for (int i = 0, length = inlined_closures->length();
         i < length;
         i++) {
      DefineDeoptimizationLiteral(inlined_closures->at(i));
    }
  
    inlined_function_count_ = deoptimization_literals_.length();
  }
  
  
  void LCodeGen::RecordSafepointWithLazyDeopt(
      LInstruction* instr, SafepointMode safepoint_mode) {
    if (safepoint_mode == RECORD_SIMPLE_SAFEPOINT) {
      RecordSafepoint(instr->pointer_map(), Safepoint::kLazyDeopt);
    } else {
      ASSERT(safepoint_mode == RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
      RecordSafepointWithRegisters(
          instr->pointer_map(), 0, Safepoint::kLazyDeopt);
    }
  }
  
  
  void LCodeGen::RecordSafepoint(
      LPointerMap* pointers,
      Safepoint::Kind kind,
      int arguments,
      Safepoint::DeoptMode deopt_mode) {
    ASSERT(expected_safepoint_kind_ == kind);
  
    const ZoneList<LOperand*>* operands = pointers->GetNormalizedOperands();
    Safepoint safepoint = safepoints_.DefineSafepoint(masm(),
        kind, arguments, deopt_mode);
    for (int i = 0; i < operands->length(); i++) {
      LOperand* pointer = operands->at(i);
      if (pointer->IsStackSlot()) {
        safepoint.DefinePointerSlot(pointer->index());
      } else if (pointer->IsRegister() && (kind & Safepoint::kWithRegisters)) {
        safepoint.DefinePointerRegister(ToRegister(pointer));
      }
    }
    if (kind & Safepoint::kWithRegisters) {
      // Register cp always contains a pointer to the context.
      safepoint.DefinePointerRegister(cp);
    }
  }
  
  
  void LCodeGen::RecordSafepoint(LPointerMap* pointers,
                                 Safepoint::DeoptMode deopt_mode) {
    RecordSafepoint(pointers, Safepoint::kSimple, 0, deopt_mode);
  }
  
  
  void LCodeGen::RecordSafepoint(Safepoint::DeoptMode deopt_mode) {
    LPointerMap empty_pointers(RelocInfo::kNoPosition);
    RecordSafepoint(&empty_pointers, deopt_mode);
  }
  
  
  void LCodeGen::RecordSafepointWithRegisters(LPointerMap* pointers,
                                              int arguments,
                                              Safepoint::DeoptMode deopt_mode) {
    RecordSafepoint(
        pointers, Safepoint::kWithRegisters, arguments, deopt_mode);
  }
  
  
  void LCodeGen::RecordSafepointWithRegistersAndDoubles(
      LPointerMap* pointers,
      int arguments,
      Safepoint::DeoptMode deopt_mode) {
    RecordSafepoint(
        pointers, Safepoint::kWithRegistersAndDoubles, arguments, deopt_mode);
  }
  
  
  void LCodeGen::RecordPosition(int position) {
    if (position == RelocInfo::kNoPosition) return;
    masm()->positions_recorder()->RecordPosition(position);
  }
  
  
  void LCodeGen::DoLabel(LLabel* label) {
    if (label->is_loop_header()) {
      Comment(";;; B%d - LOOP entry", label->block_id());
    } else {
      Comment(";;; B%d", label->block_id());
    }
    __ bind(label->label());
    current_block_ = label->block_id();
    DoGap(label);
  }
  
  
  void LCodeGen::DoParallelMove(LParallelMove* move) {
    resolver_.Resolve(move);
  }
  
  
  void LCodeGen::DoGap(LGap* gap) {
    for (int i = LGap::FIRST_INNER_POSITION;
         i <= LGap::LAST_INNER_POSITION;
         i++) {
      LGap::InnerPosition inner_pos = static_cast<LGap::InnerPosition>(i);
      LParallelMove* move = gap->GetParallelMove(inner_pos);
      if (move != NULL) DoParallelMove(move);
    }
  }
  
  
  void LCodeGen::DoInstructionGap(LInstructionGap* instr) {
    DoGap(instr);
  }
  
  
  void LCodeGen::DoParameter(LParameter* instr) {
    // Nothing to do.
  }
  
  
  void LCodeGen::DoCallStub(LCallStub* instr) {
    ASSERT(ToRegister(instr->result()).is(r0));
    switch (instr->hydrogen()->major_key()) {
      case CodeStub::RegExpConstructResult: {
        RegExpConstructResultStub stub;
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::RegExpExec: {
        RegExpExecStub stub;
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::SubString: {
        SubStringStub stub;
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::NumberToString: {
        NumberToStringStub stub;
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::StringAdd: {
        StringAddStub stub(NO_STRING_ADD_FLAGS);
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::StringCompare: {
        StringCompareStub stub;
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::TranscendentalCache: {
        __ ldr(r0, MemOperand(sp, 0));
        TranscendentalCacheStub stub(instr->transcendental_type(),
                                     TranscendentalCacheStub::TAGGED);
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      default:
        UNREACHABLE();
    }
  }
  
  
  void LCodeGen::DoUnknownOSRValue(LUnknownOSRValue* instr) {
    // Nothing to do.
  }
  
  
  void LCodeGen::DoModI(LModI* instr) {
    if (instr->hydrogen()->HasPowerOf2Divisor()) {
      Register dividend = ToRegister(instr->InputAt(0));
      Register result = ToRegister(instr->result());
  
      int32_t divisor =
          HConstant::cast(instr->hydrogen()->right())->Integer32Value();
  
      if (divisor < 0) divisor = -divisor;
  
      Label positive_dividend, done;
      __ cmp(dividend, Operand(0));
      __ b(pl, &positive_dividend);
      __ rsb(result, dividend, Operand(0));
      __ and_(result, result, Operand(divisor - 1), SetCC);
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        DeoptimizeIf(eq, instr->environment());
      }
      __ rsb(result, result, Operand(0));
      __ b(&done);
      __ bind(&positive_dividend);
      __ and_(result, dividend, Operand(divisor - 1));
      __ bind(&done);
      return;
    }
  
    // These registers hold untagged 32 bit values.
    Register left = ToRegister(instr->InputAt(0));
    Register right = ToRegister(instr->InputAt(1));
    Register result = ToRegister(instr->result());
  
    Register scratch = scratch0();
    Register scratch2 = ToRegister(instr->TempAt(0));
    DwVfpRegister dividend = ToDoubleRegister(instr->TempAt(1));
    DwVfpRegister divisor = ToDoubleRegister(instr->TempAt(2));
    DwVfpRegister quotient = double_scratch0();
  
    ASSERT(!dividend.is(divisor));
    ASSERT(!dividend.is(quotient));
    ASSERT(!divisor.is(quotient));
    ASSERT(!scratch.is(left));
    ASSERT(!scratch.is(right));
    ASSERT(!scratch.is(result));
  
    Label done, vfp_modulo, both_positive, right_negative;
  
    // Check for x % 0.
    if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
      __ cmp(right, Operand(0));
      DeoptimizeIf(eq, instr->environment());
    }
  
    __ Move(result, left);
  
    // (0 % x) must yield 0 (if x is finite, which is the case here).
    __ cmp(left, Operand(0));
    __ b(eq, &done);
    // Preload right in a vfp register.
    __ vmov(divisor.low(), right);
    __ b(lt, &vfp_modulo);
  
    __ cmp(left, Operand(right));
    __ b(lt, &done);
  
    // Check for (positive) power of two on the right hand side.
    __ JumpIfNotPowerOfTwoOrZeroAndNeg(right,
                                       scratch,
                                       &right_negative,
                                       &both_positive);
    // Perform modulo operation (scratch contains right - 1).
    __ and_(result, scratch, Operand(left));
    __ b(&done);
  
    __ bind(&right_negative);
    // Negate right. The sign of the divisor does not matter.
    __ rsb(right, right, Operand(0));
  
    __ bind(&both_positive);
    const int kUnfolds = 3;
    // If the right hand side is smaller than the (nonnegative)
    // left hand side, the left hand side is the result.
    // Else try a few subtractions of the left hand side.
    __ mov(scratch, left);
    for (int i = 0; i < kUnfolds; i++) {
      // Check if the left hand side is less or equal than the
      // the right hand side.
      __ cmp(scratch, Operand(right));
      __ mov(result, scratch, LeaveCC, lt);
      __ b(lt, &done);
      // If not, reduce the left hand side by the right hand
      // side and check again.
      if (i < kUnfolds - 1) __ sub(scratch, scratch, right);
    }
  
    __ bind(&vfp_modulo);
    // Load the arguments in VFP registers.
    // The divisor value is preloaded before. Be careful that 'right' is only live
    // on entry.
    __ vmov(dividend.low(), left);
    // From here on don't use right as it may have been reallocated (for example
    // to scratch2).
    right = no_reg;
  
    __ vcvt_f64_s32(dividend, dividend.low());
    __ vcvt_f64_s32(divisor, divisor.low());
  
    // We do not care about the sign of the divisor.
    __ vabs(divisor, divisor);
    // Compute the quotient and round it to a 32bit integer.
    __ vdiv(quotient, dividend, divisor);
    __ vcvt_s32_f64(quotient.low(), quotient);
    __ vcvt_f64_s32(quotient, quotient.low());
  
    // Compute the remainder in result.
    DwVfpRegister double_scratch = dividend;
    __ vmul(double_scratch, divisor, quotient);
    __ vcvt_s32_f64(double_scratch.low(), double_scratch);
    __ vmov(scratch, double_scratch.low());
  
    if (!instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ sub(result, left, scratch);
    } else {
      Label ok;
      // Check for -0.
      __ sub(scratch2, left, scratch, SetCC);
      __ b(ne, &ok);
      __ cmp(left, Operand(0));
      DeoptimizeIf(mi, instr->environment());
      __ bind(&ok);
      // Load the result and we are done.
      __ mov(result, scratch2);
    }
  
    __ bind(&done);
  }
  
  
  void LCodeGen::DoDivI(LDivI* instr) {
    class DeferredDivI: public LDeferredCode {
     public:
      DeferredDivI(LCodeGen* codegen, LDivI* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() {
        codegen()->DoDeferredBinaryOpStub(instr_, Token::DIV);
      }
      virtual LInstruction* instr() { return instr_; }
     private:
      LDivI* instr_;
    };
  
    const Register left = ToRegister(instr->InputAt(0));
    const Register right = ToRegister(instr->InputAt(1));
    const Register scratch = scratch0();
    const Register result = ToRegister(instr->result());
  
    // Check for x / 0.
    if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
      __ cmp(right, Operand(0));
      DeoptimizeIf(eq, instr->environment());
    }
  
    // Check for (0 / -x) that will produce negative zero.
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      Label left_not_zero;
      __ cmp(left, Operand(0));
      __ b(ne, &left_not_zero);
      __ cmp(right, Operand(0));
      DeoptimizeIf(mi, instr->environment());
      __ bind(&left_not_zero);
    }
  
    // Check for (-kMinInt / -1).
    if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
      Label left_not_min_int;
      __ cmp(left, Operand(kMinInt));
      __ b(ne, &left_not_min_int);
      __ cmp(right, Operand(-1));
      DeoptimizeIf(eq, instr->environment());
      __ bind(&left_not_min_int);
    }
  
    Label done, deoptimize;
    // Test for a few common cases first.
    __ cmp(right, Operand(1));
    __ mov(result, left, LeaveCC, eq);
    __ b(eq, &done);
  
    __ cmp(right, Operand(2));
    __ tst(left, Operand(1), eq);
    __ mov(result, Operand(left, ASR, 1), LeaveCC, eq);
    __ b(eq, &done);
  
    __ cmp(right, Operand(4));
    __ tst(left, Operand(3), eq);
    __ mov(result, Operand(left, ASR, 2), LeaveCC, eq);
    __ b(eq, &done);
  
    // Call the stub. The numbers in r0 and r1 have
    // to be tagged to Smis. If that is not possible, deoptimize.
    DeferredDivI* deferred = new DeferredDivI(this, instr);
  
    __ TrySmiTag(left, &deoptimize, scratch);
    __ TrySmiTag(right, &deoptimize, scratch);
  
    __ b(al, deferred->entry());
    __ bind(deferred->exit());
  
    // If the result in r0 is a Smi, untag it, else deoptimize.
    __ JumpIfNotSmi(result, &deoptimize);
    __ SmiUntag(result);
    __ b(&done);
  
    __ bind(&deoptimize);
    DeoptimizeIf(al, instr->environment());
    __ bind(&done);
  }
  
  
  template<int T>
  void LCodeGen::DoDeferredBinaryOpStub(LTemplateInstruction<1, 2, T>* instr,
                                        Token::Value op) {
    Register left = ToRegister(instr->InputAt(0));
    Register right = ToRegister(instr->InputAt(1));
  
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegistersAndDoubles);
    // Move left to r1 and right to r0 for the stub call.
    if (left.is(r1)) {
      __ Move(r0, right);
    } else if (left.is(r0) && right.is(r1)) {
      __ Swap(r0, r1, r2);
    } else if (left.is(r0)) {
      ASSERT(!right.is(r1));
      __ mov(r1, r0);
      __ mov(r0, right);
    } else {
      ASSERT(!left.is(r0) && !right.is(r0));
      __ mov(r0, right);
      __ mov(r1, left);
    }
    BinaryOpStub stub(op, OVERWRITE_LEFT);
    __ CallStub(&stub);
    RecordSafepointWithRegistersAndDoubles(instr->pointer_map(),
                                           0,
                                           Safepoint::kNoLazyDeopt);
    // Overwrite the stored value of r0 with the result of the stub.
    __ StoreToSafepointRegistersAndDoublesSlot(r0, r0);
  }
  
  
  void LCodeGen::DoMulI(LMulI* instr) {
    Register scratch = scratch0();
    Register result = ToRegister(instr->result());
    // Note that result may alias left.
    Register left = ToRegister(instr->InputAt(0));
    LOperand* right_op = instr->InputAt(1);
  
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    bool bailout_on_minus_zero =
      instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);
  
    if (right_op->IsConstantOperand() && !can_overflow) {
      // Use optimized code for specific constants.
      int32_t constant = ToInteger32(LConstantOperand::cast(right_op));
  
      if (bailout_on_minus_zero && (constant < 0)) {
        // The case of a null constant will be handled separately.
        // If constant is negative and left is null, the result should be -0.
        __ cmp(left, Operand(0));
        DeoptimizeIf(eq, instr->environment());
      }
  
      switch (constant) {
        case -1:
          __ rsb(result, left, Operand(0));
          break;
        case 0:
          if (bailout_on_minus_zero) {
            // If left is strictly negative and the constant is null, the
            // result is -0. Deoptimize if required, otherwise return 0.
            __ cmp(left, Operand(0));
            DeoptimizeIf(mi, instr->environment());
          }
          __ mov(result, Operand(0));
          break;
        case 1:
          __ Move(result, left);
          break;
        default:
          // Multiplying by powers of two and powers of two plus or minus
          // one can be done faster with shifted operands.
          // For other constants we emit standard code.
          int32_t mask = constant >> 31;
          uint32_t constant_abs = (constant + mask) ^ mask;
  
          if (IsPowerOf2(constant_abs) ||
              IsPowerOf2(constant_abs - 1) ||
              IsPowerOf2(constant_abs + 1)) {
            if (IsPowerOf2(constant_abs)) {
              int32_t shift = WhichPowerOf2(constant_abs);
              __ mov(result, Operand(left, LSL, shift));
            } else if (IsPowerOf2(constant_abs - 1)) {
              int32_t shift = WhichPowerOf2(constant_abs - 1);
              __ add(result, left, Operand(left, LSL, shift));
            } else if (IsPowerOf2(constant_abs + 1)) {
              int32_t shift = WhichPowerOf2(constant_abs + 1);
              __ rsb(result, left, Operand(left, LSL, shift));
            }
  
            // Correct the sign of the result is the constant is negative.
            if (constant < 0)  __ rsb(result, result, Operand(0));
  
          } else {
            // Generate standard code.
            __ mov(ip, Operand(constant));
            __ mul(result, left, ip);
          }
      }
  
    } else {
      Register right = EmitLoadRegister(right_op, scratch);
      if (bailout_on_minus_zero) {
        __ orr(ToRegister(instr->TempAt(0)), left, right);
      }
  
      if (can_overflow) {
        // scratch:result = left * right.
        __ smull(result, scratch, left, right);
        __ cmp(scratch, Operand(result, ASR, 31));
        DeoptimizeIf(ne, instr->environment());
      } else {
        __ mul(result, left, right);
      }
  
      if (bailout_on_minus_zero) {
        // Bail out if the result is supposed to be negative zero.
        Label done;
        __ cmp(result, Operand(0));
        __ b(ne, &done);
        __ cmp(ToRegister(instr->TempAt(0)), Operand(0));
        DeoptimizeIf(mi, instr->environment());
        __ bind(&done);
      }
    }
  }
  
  
  void LCodeGen::DoBitI(LBitI* instr) {
    LOperand* left_op = instr->InputAt(0);
    LOperand* right_op = instr->InputAt(1);
    ASSERT(left_op->IsRegister());
    Register left = ToRegister(left_op);
    Register result = ToRegister(instr->result());
    Operand right(no_reg);
  
    if (right_op->IsStackSlot() || right_op->IsArgument()) {
      right = Operand(EmitLoadRegister(right_op, ip));
    } else {
      ASSERT(right_op->IsRegister() || right_op->IsConstantOperand());
      right = ToOperand(right_op);
    }
  
    switch (instr->op()) {
      case Token::BIT_AND:
        __ and_(result, left, right);
        break;
      case Token::BIT_OR:
        __ orr(result, left, right);
        break;
      case Token::BIT_XOR:
        __ eor(result, left, right);
        break;
      default:
        UNREACHABLE();
        break;
    }
  }
  
  
  void LCodeGen::DoShiftI(LShiftI* instr) {
    // Both 'left' and 'right' are "used at start" (see LCodeGen::DoShift), so
    // result may alias either of them.
    LOperand* right_op = instr->InputAt(1);
    Register left = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
    if (right_op->IsRegister()) {
      // Mask the right_op operand.
      __ and_(scratch, ToRegister(right_op), Operand(0x1F));
      switch (instr->op()) {
        case Token::SAR:
          __ mov(result, Operand(left, ASR, scratch));
          break;
        case Token::SHR:
          if (instr->can_deopt()) {
            __ mov(result, Operand(left, LSR, scratch), SetCC);
            DeoptimizeIf(mi, instr->environment());
          } else {
            __ mov(result, Operand(left, LSR, scratch));
          }
          break;
        case Token::SHL:
          __ mov(result, Operand(left, LSL, scratch));
          break;
        default:
          UNREACHABLE();
          break;
      }
    } else {
      // Mask the right_op operand.
      int value = ToInteger32(LConstantOperand::cast(right_op));
      uint8_t shift_count = static_cast<uint8_t>(value & 0x1F);
      switch (instr->op()) {
        case Token::SAR:
          if (shift_count != 0) {
            __ mov(result, Operand(left, ASR, shift_count));
          } else {
            __ Move(result, left);
          }
          break;
        case Token::SHR:
          if (shift_count != 0) {
            __ mov(result, Operand(left, LSR, shift_count));
          } else {
            if (instr->can_deopt()) {
              __ tst(left, Operand(0x80000000));
              DeoptimizeIf(ne, instr->environment());
            }
            __ Move(result, left);
          }
          break;
        case Token::SHL:
          if (shift_count != 0) {
            __ mov(result, Operand(left, LSL, shift_count));
          } else {
            __ Move(result, left);
          }
          break;
        default:
          UNREACHABLE();
          break;
      }
    }
  }
  
  
  void LCodeGen::DoSubI(LSubI* instr) {
    LOperand* left = instr->InputAt(0);
    LOperand* right = instr->InputAt(1);
    LOperand* result = instr->result();
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    SBit set_cond = can_overflow ? SetCC : LeaveCC;
  
    if (right->IsStackSlot() || right->IsArgument()) {
      Register right_reg = EmitLoadRegister(right, ip);
      __ sub(ToRegister(result), ToRegister(left), Operand(right_reg), set_cond);
    } else {
      ASSERT(right->IsRegister() || right->IsConstantOperand());
      __ sub(ToRegister(result), ToRegister(left), ToOperand(right), set_cond);
    }
  
    if (can_overflow) {
      DeoptimizeIf(vs, instr->environment());
    }
  }
  
  
  void LCodeGen::DoConstantI(LConstantI* instr) {
    ASSERT(instr->result()->IsRegister());
    __ mov(ToRegister(instr->result()), Operand(instr->value()));
  }
  
  
  void LCodeGen::DoConstantD(LConstantD* instr) {
    ASSERT(instr->result()->IsDoubleRegister());
    DwVfpRegister result = ToDoubleRegister(instr->result());
    double v = instr->value();
    __ Vmov(result, v);
  }
  
  
  void LCodeGen::DoConstantT(LConstantT* instr) {
    Handle<Object> value = instr->value();
    if (value->IsSmi()) {
      __ mov(ToRegister(instr->result()), Operand(value));
    } else {
      __ LoadHeapObject(ToRegister(instr->result()),
                        Handle<HeapObject>::cast(value));
    }
  }
  
  
  void LCodeGen::DoJSArrayLength(LJSArrayLength* instr) {
    Register result = ToRegister(instr->result());
    Register array = ToRegister(instr->InputAt(0));
    __ ldr(result, FieldMemOperand(array, JSArray::kLengthOffset));
  }
  
  
  void LCodeGen::DoFixedArrayBaseLength(LFixedArrayBaseLength* instr) {
    Register result = ToRegister(instr->result());
    Register array = ToRegister(instr->InputAt(0));
    __ ldr(result, FieldMemOperand(array, FixedArrayBase::kLengthOffset));
  }
  
  
  void LCodeGen::DoElementsKind(LElementsKind* instr) {
    Register result = ToRegister(instr->result());
    Register input = ToRegister(instr->InputAt(0));
  
    // Load map into |result|.
    __ ldr(result, FieldMemOperand(input, HeapObject::kMapOffset));
    // Load the map's "bit field 2" into |result|. We only need the first byte,
    // but the following bit field extraction takes care of that anyway.
    __ ldr(result, FieldMemOperand(result, Map::kBitField2Offset));
    // Retrieve elements_kind from bit field 2.
    __ ubfx(result, result, Map::kElementsKindShift, Map::kElementsKindBitCount);
  }
  
  
  void LCodeGen::DoValueOf(LValueOf* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    Register map = ToRegister(instr->TempAt(0));
    Label done;
  
    // If the object is a smi return the object.
    __ tst(input, Operand(kSmiTagMask));
    __ Move(result, input, eq);
    __ b(eq, &done);
  
    // If the object is not a value type, return the object.
    __ CompareObjectType(input, map, map, JS_VALUE_TYPE);
    __ Move(result, input, ne);
    __ b(ne, &done);
    __ ldr(result, FieldMemOperand(input, JSValue::kValueOffset));
  
    __ bind(&done);
  }
  
  
  void LCodeGen::DoDateField(LDateField* instr) {
    Register object = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    Register scratch = ToRegister(instr->TempAt(0));
    Smi* index = instr->index();
    Label runtime, done;
    ASSERT(object.is(result));
    ASSERT(object.is(r0));
    ASSERT(!scratch.is(scratch0()));
    ASSERT(!scratch.is(object));
  
  #ifdef DEBUG
    __ AbortIfSmi(object);
    __ CompareObjectType(object, scratch, scratch, JS_DATE_TYPE);
    __ Assert(eq, "Trying to get date field from non-date.");
  #endif
  
    if (index->value() == 0) {
      __ ldr(result, FieldMemOperand(object, JSDate::kValueOffset));
    } else {
      if (index->value() < JSDate::kFirstUncachedField) {
        ExternalReference stamp = ExternalReference::date_cache_stamp(isolate());
        __ mov(scratch, Operand(stamp));
        __ ldr(scratch, MemOperand(scratch));
        __ ldr(scratch0(), FieldMemOperand(object, JSDate::kCacheStampOffset));
        __ cmp(scratch, scratch0());
        __ b(ne, &runtime);
        __ ldr(result, FieldMemOperand(object, JSDate::kValueOffset +
                                               kPointerSize * index->value()));
        __ jmp(&done);
      }
      __ bind(&runtime);
      __ PrepareCallCFunction(2, scratch);
      __ mov(r1, Operand(index));
      __ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2);
      __ bind(&done);
    }
  }
  
  
  void LCodeGen::DoBitNotI(LBitNotI* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    __ mvn(result, Operand(input));
  }
  
  
  void LCodeGen::DoThrow(LThrow* instr) {
    Register input_reg = EmitLoadRegister(instr->InputAt(0), ip);
    __ push(input_reg);
    CallRuntime(Runtime::kThrow, 1, instr);
  
    if (FLAG_debug_code) {
      __ stop("Unreachable code.");
    }
  }
  
  
  void LCodeGen::DoAddI(LAddI* instr) {
    LOperand* left = instr->InputAt(0);
    LOperand* right = instr->InputAt(1);
    LOperand* result = instr->result();
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    SBit set_cond = can_overflow ? SetCC : LeaveCC;
  
    if (right->IsStackSlot() || right->IsArgument()) {
      Register right_reg = EmitLoadRegister(right, ip);
      __ add(ToRegister(result), ToRegister(left), Operand(right_reg), set_cond);
    } else {
      ASSERT(right->IsRegister() || right->IsConstantOperand());
      __ add(ToRegister(result), ToRegister(left), ToOperand(right), set_cond);
    }
  
    if (can_overflow) {
      DeoptimizeIf(vs, instr->environment());
    }
  }
  
  
  void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
    DoubleRegister left = ToDoubleRegister(instr->InputAt(0));
    DoubleRegister right = ToDoubleRegister(instr->InputAt(1));
    DoubleRegister result = ToDoubleRegister(instr->result());
    switch (instr->op()) {
      case Token::ADD:
        __ vadd(result, left, right);
        break;
      case Token::SUB:
        __ vsub(result, left, right);
        break;
      case Token::MUL:
        __ vmul(result, left, right);
        break;
      case Token::DIV:
        __ vdiv(result, left, right);
        break;
      case Token::MOD: {
        // Save r0-r3 on the stack.
        __ stm(db_w, sp, r0.bit() | r1.bit() | r2.bit() | r3.bit());
  
        __ PrepareCallCFunction(0, 2, scratch0());
        __ SetCallCDoubleArguments(left, right);
        __ CallCFunction(
            ExternalReference::double_fp_operation(Token::MOD, isolate()),
            0, 2);
        // Move the result in the double result register.
        __ GetCFunctionDoubleResult(result);
  
        // Restore r0-r3.
        __ ldm(ia_w, sp, r0.bit() | r1.bit() | r2.bit() | r3.bit());
        break;
      }
      default:
        UNREACHABLE();
        break;
    }
  }
  
  
  void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
    ASSERT(ToRegister(instr->InputAt(0)).is(r1));
    ASSERT(ToRegister(instr->InputAt(1)).is(r0));
    ASSERT(ToRegister(instr->result()).is(r0));
  
    BinaryOpStub stub(instr->op(), NO_OVERWRITE);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    __ nop();  // Signals no inlined code.
  }
  
  
  int LCodeGen::GetNextEmittedBlock(int block) {
    for (int i = block + 1; i < graph()->blocks()->length(); ++i) {
      LLabel* label = chunk_->GetLabel(i);
      if (!label->HasReplacement()) return i;
    }
    return -1;
  }
  
  
  void LCodeGen::EmitBranch(int left_block, int right_block, Condition cc) {
    int next_block = GetNextEmittedBlock(current_block_);
    right_block = chunk_->LookupDestination(right_block);
    left_block = chunk_->LookupDestination(left_block);
  
    if (right_block == left_block) {
      EmitGoto(left_block);
    } else if (left_block == next_block) {
      __ b(NegateCondition(cc), chunk_->GetAssemblyLabel(right_block));
    } else if (right_block == next_block) {
      __ b(cc, chunk_->GetAssemblyLabel(left_block));
    } else {
      __ b(cc, chunk_->GetAssemblyLabel(left_block));
      __ b(chunk_->GetAssemblyLabel(right_block));
    }
  }
  
  
  void LCodeGen::DoBranch(LBranch* instr) {
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    Representation r = instr->hydrogen()->value()->representation();
    if (r.IsInteger32()) {
      Register reg = ToRegister(instr->InputAt(0));
      __ cmp(reg, Operand(0));
      EmitBranch(true_block, false_block, ne);
    } else if (r.IsDouble()) {
      DoubleRegister reg = ToDoubleRegister(instr->InputAt(0));
      Register scratch = scratch0();
  
      // Test the double value. Zero and NaN are false.
      __ VFPCompareAndLoadFlags(reg, 0.0, scratch);
      __ tst(scratch, Operand(kVFPZConditionFlagBit | kVFPVConditionFlagBit));
      EmitBranch(true_block, false_block, eq);
    } else {
      ASSERT(r.IsTagged());
      Register reg = ToRegister(instr->InputAt(0));
      HType type = instr->hydrogen()->value()->type();
      if (type.IsBoolean()) {
        __ CompareRoot(reg, Heap::kTrueValueRootIndex);
        EmitBranch(true_block, false_block, eq);
      } else if (type.IsSmi()) {
        __ cmp(reg, Operand(0));
        EmitBranch(true_block, false_block, ne);
      } else {
        Label* true_label = chunk_->GetAssemblyLabel(true_block);
        Label* false_label = chunk_->GetAssemblyLabel(false_block);
  
        ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
        // Avoid deopts in the case where we've never executed this path before.
        if (expected.IsEmpty()) expected = ToBooleanStub::all_types();
  
        if (expected.Contains(ToBooleanStub::UNDEFINED)) {
          // undefined -> false.
          __ CompareRoot(reg, Heap::kUndefinedValueRootIndex);
          __ b(eq, false_label);
        }
        if (expected.Contains(ToBooleanStub::BOOLEAN)) {
          // Boolean -> its value.
          __ CompareRoot(reg, Heap::kTrueValueRootIndex);
          __ b(eq, true_label);
          __ CompareRoot(reg, Heap::kFalseValueRootIndex);
          __ b(eq, false_label);
        }
        if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
          // 'null' -> false.
          __ CompareRoot(reg, Heap::kNullValueRootIndex);
          __ b(eq, false_label);
        }
  
        if (expected.Contains(ToBooleanStub::SMI)) {
          // Smis: 0 -> false, all other -> true.
          __ cmp(reg, Operand(0));
          __ b(eq, false_label);
          __ JumpIfSmi(reg, true_label);
        } else if (expected.NeedsMap()) {
          // If we need a map later and have a Smi -> deopt.
          __ tst(reg, Operand(kSmiTagMask));
          DeoptimizeIf(eq, instr->environment());
        }
  
        const Register map = scratch0();
        if (expected.NeedsMap()) {
          __ ldr(map, FieldMemOperand(reg, HeapObject::kMapOffset));
  
          if (expected.CanBeUndetectable()) {
            // Undetectable -> false.
            __ ldrb(ip, FieldMemOperand(map, Map::kBitFieldOffset));
            __ tst(ip, Operand(1 << Map::kIsUndetectable));
            __ b(ne, false_label);
          }
        }
  
        if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
          // spec object -> true.
          __ CompareInstanceType(map, ip, FIRST_SPEC_OBJECT_TYPE);
          __ b(ge, true_label);
        }
  
        if (expected.Contains(ToBooleanStub::STRING)) {
          // String value -> false iff empty.
          Label not_string;
          __ CompareInstanceType(map, ip, FIRST_NONSTRING_TYPE);
          __ b(ge, &not_string);
          __ ldr(ip, FieldMemOperand(reg, String::kLengthOffset));
          __ cmp(ip, Operand(0));
          __ b(ne, true_label);
          __ b(false_label);
          __ bind(&not_string);
        }
  
        if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
          // heap number -> false iff +0, -0, or NaN.
          DoubleRegister dbl_scratch = double_scratch0();
          Label not_heap_number;
          __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
          __ b(ne, &not_heap_number);
          __ vldr(dbl_scratch, FieldMemOperand(reg, HeapNumber::kValueOffset));
          __ VFPCompareAndSetFlags(dbl_scratch, 0.0);
          __ b(vs, false_label);  // NaN -> false.
          __ b(eq, false_label);  // +0, -0 -> false.
          __ b(true_label);
          __ bind(&not_heap_number);
        }
  
        // We've seen something for the first time -> deopt.
        DeoptimizeIf(al, instr->environment());
      }
    }
  }
  
  
  void LCodeGen::EmitGoto(int block) {
    block = chunk_->LookupDestination(block);
    int next_block = GetNextEmittedBlock(current_block_);
    if (block != next_block) {
      __ jmp(chunk_->GetAssemblyLabel(block));
    }
  }
  
  
  void LCodeGen::DoGoto(LGoto* instr) {
    EmitGoto(instr->block_id());
  }
  
  
  Condition LCodeGen::TokenToCondition(Token::Value op, bool is_unsigned) {
    Condition cond = kNoCondition;
    switch (op) {
      case Token::EQ:
      case Token::EQ_STRICT:
        cond = eq;
        break;
      case Token::LT:
        cond = is_unsigned ? lo : lt;
        break;
      case Token::GT:
        cond = is_unsigned ? hi : gt;
        break;
      case Token::LTE:
        cond = is_unsigned ? ls : le;
        break;
      case Token::GTE:
        cond = is_unsigned ? hs : ge;
        break;
      case Token::IN:
      case Token::INSTANCEOF:
      default:
        UNREACHABLE();
    }
    return cond;
  }
  
  
  void LCodeGen::DoCmpIDAndBranch(LCmpIDAndBranch* instr) {
    LOperand* left = instr->InputAt(0);
    LOperand* right = instr->InputAt(1);
    int false_block = chunk_->LookupDestination(instr->false_block_id());
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    Condition cond = TokenToCondition(instr->op(), false);
  
    if (left->IsConstantOperand() && right->IsConstantOperand()) {
      // We can statically evaluate the comparison.
      double left_val = ToDouble(LConstantOperand::cast(left));
      double right_val = ToDouble(LConstantOperand::cast(right));
      int next_block =
        EvalComparison(instr->op(), left_val, right_val) ? true_block
                                                         : false_block;
      EmitGoto(next_block);
    } else {
      if (instr->is_double()) {
        // Compare left and right operands as doubles and load the
        // resulting flags into the normal status register.
        __ VFPCompareAndSetFlags(ToDoubleRegister(left), ToDoubleRegister(right));
        // If a NaN is involved, i.e. the result is unordered (V set),
        // jump to false block label.
        __ b(vs, chunk_->GetAssemblyLabel(false_block));
      } else {
        if (right->IsConstantOperand()) {
          __ cmp(ToRegister(left),
                 Operand(ToInteger32(LConstantOperand::cast(right))));
        } else if (left->IsConstantOperand()) {
          __ cmp(ToRegister(right),
                 Operand(ToInteger32(LConstantOperand::cast(left))));
          // We transposed the operands. Reverse the condition.
          cond = ReverseCondition(cond);
        } else {
          __ cmp(ToRegister(left), ToRegister(right));
        }
      }
      EmitBranch(true_block, false_block, cond);
    }
  }
  
  
  void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
    Register left = ToRegister(instr->InputAt(0));
    Register right = ToRegister(instr->InputAt(1));
    int false_block = chunk_->LookupDestination(instr->false_block_id());
    int true_block = chunk_->LookupDestination(instr->true_block_id());
  
    __ cmp(left, Operand(right));
    EmitBranch(true_block, false_block, eq);
  }
  
  
  void LCodeGen::DoCmpConstantEqAndBranch(LCmpConstantEqAndBranch* instr) {
    Register left = ToRegister(instr->InputAt(0));
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    __ cmp(left, Operand(instr->hydrogen()->right()));
    EmitBranch(true_block, false_block, eq);
  }
  
  
  void LCodeGen::DoIsNilAndBranch(LIsNilAndBranch* instr) {
    Register scratch = scratch0();
    Register reg = ToRegister(instr->InputAt(0));
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    // If the expression is known to be untagged or a smi, then it's definitely
    // not null, and it can't be a an undetectable object.
    if (instr->hydrogen()->representation().IsSpecialization() ||
        instr->hydrogen()->type().IsSmi()) {
      EmitGoto(false_block);
      return;
    }
  
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    Heap::RootListIndex nil_value = instr->nil() == kNullValue ?
        Heap::kNullValueRootIndex :
        Heap::kUndefinedValueRootIndex;
    __ LoadRoot(ip, nil_value);
    __ cmp(reg, ip);
    if (instr->kind() == kStrictEquality) {
      EmitBranch(true_block, false_block, eq);
    } else {
      Heap::RootListIndex other_nil_value = instr->nil() == kNullValue ?
          Heap::kUndefinedValueRootIndex :
          Heap::kNullValueRootIndex;
      Label* true_label = chunk_->GetAssemblyLabel(true_block);
      Label* false_label = chunk_->GetAssemblyLabel(false_block);
      __ b(eq, true_label);
      __ LoadRoot(ip, other_nil_value);
      __ cmp(reg, ip);
      __ b(eq, true_label);
      __ JumpIfSmi(reg, false_label);
      // Check for undetectable objects by looking in the bit field in
      // the map. The object has already been smi checked.
      __ ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
      __ ldrb(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
      __ tst(scratch, Operand(1 << Map::kIsUndetectable));
      EmitBranch(true_block, false_block, ne);
    }
  }
  
  
  Condition LCodeGen::EmitIsObject(Register input,
                                   Register temp1,
                                   Label* is_not_object,
                                   Label* is_object) {
    Register temp2 = scratch0();
    __ JumpIfSmi(input, is_not_object);
  
    __ LoadRoot(temp2, Heap::kNullValueRootIndex);
    __ cmp(input, temp2);
    __ b(eq, is_object);
  
    // Load map.
    __ ldr(temp1, FieldMemOperand(input, HeapObject::kMapOffset));
    // Undetectable objects behave like undefined.
    __ ldrb(temp2, FieldMemOperand(temp1, Map::kBitFieldOffset));
    __ tst(temp2, Operand(1 << Map::kIsUndetectable));
    __ b(ne, is_not_object);
  
    // Load instance type and check that it is in object type range.
    __ ldrb(temp2, FieldMemOperand(temp1, Map::kInstanceTypeOffset));
    __ cmp(temp2, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
    __ b(lt, is_not_object);
    __ cmp(temp2, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
    return le;
  }
  
  
  void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
    Register reg = ToRegister(instr->InputAt(0));
    Register temp1 = ToRegister(instr->TempAt(0));
  
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
    Label* true_label = chunk_->GetAssemblyLabel(true_block);
    Label* false_label = chunk_->GetAssemblyLabel(false_block);
  
    Condition true_cond =
        EmitIsObject(reg, temp1, false_label, true_label);
  
    EmitBranch(true_block, false_block, true_cond);
  }
  
  
  Condition LCodeGen::EmitIsString(Register input,
                                   Register temp1,
                                   Label* is_not_string) {
    __ JumpIfSmi(input, is_not_string);
    __ CompareObjectType(input, temp1, temp1, FIRST_NONSTRING_TYPE);
  
    return lt;
  }
  
  
  void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
    Register reg = ToRegister(instr->InputAt(0));
    Register temp1 = ToRegister(instr->TempAt(0));
  
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
    Label* false_label = chunk_->GetAssemblyLabel(false_block);
  
    Condition true_cond =
        EmitIsString(reg, temp1, false_label);
  
    EmitBranch(true_block, false_block, true_cond);
  }
  
  
  void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    Register input_reg = EmitLoadRegister(instr->InputAt(0), ip);
    __ tst(input_reg, Operand(kSmiTagMask));
    EmitBranch(true_block, false_block, eq);
  }
  
  
  void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register temp = ToRegister(instr->TempAt(0));
  
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    __ JumpIfSmi(input, chunk_->GetAssemblyLabel(false_block));
    __ ldr(temp, FieldMemOperand(input, HeapObject::kMapOffset));
    __ ldrb(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
    __ tst(temp, Operand(1 << Map::kIsUndetectable));
    EmitBranch(true_block, false_block, ne);
  }
  
  
  static Condition ComputeCompareCondition(Token::Value op) {
    switch (op) {
      case Token::EQ_STRICT:
      case Token::EQ:
        return eq;
      case Token::LT:
        return lt;
      case Token::GT:
        return gt;
      case Token::LTE:
        return le;
      case Token::GTE:
        return ge;
      default:
        UNREACHABLE();
        return kNoCondition;
    }
  }
  
  
  void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
    Token::Value op = instr->op();
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    Handle<Code> ic = CompareIC::GetUninitialized(op);
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
    __ cmp(r0, Operand(0));  // This instruction also signals no smi code inlined.
  
    Condition condition = ComputeCompareCondition(op);
  
    EmitBranch(true_block, false_block, condition);
  }
  
  
  static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
    InstanceType from = instr->from();
    InstanceType to = instr->to();
    if (from == FIRST_TYPE) return to;
    ASSERT(from == to || to == LAST_TYPE);
    return from;
  }
  
  
  static Condition BranchCondition(HHasInstanceTypeAndBranch* instr) {
    InstanceType from = instr->from();
    InstanceType to = instr->to();
    if (from == to) return eq;
    if (to == LAST_TYPE) return hs;
    if (from == FIRST_TYPE) return ls;
    UNREACHABLE();
    return eq;
  }
  
  
  void LCodeGen::DoHasInstanceTypeAndBranch(LHasInstanceTypeAndBranch* instr) {
    Register scratch = scratch0();
    Register input = ToRegister(instr->InputAt(0));
  
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    Label* false_label = chunk_->GetAssemblyLabel(false_block);
  
    __ JumpIfSmi(input, false_label);
  
    __ CompareObjectType(input, scratch, scratch, TestType(instr->hydrogen()));
    EmitBranch(true_block, false_block, BranchCondition(instr->hydrogen()));
  }
  
  
  void LCodeGen::DoGetCachedArrayIndex(LGetCachedArrayIndex* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
  
    if (FLAG_debug_code) {
      __ AbortIfNotString(input);
    }
  
    __ ldr(result, FieldMemOperand(input, String::kHashFieldOffset));
    __ IndexFromHash(result, result);
  }
  
  
  void LCodeGen::DoHasCachedArrayIndexAndBranch(
      LHasCachedArrayIndexAndBranch* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register scratch = scratch0();
  
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    __ ldr(scratch,
           FieldMemOperand(input, String::kHashFieldOffset));
    __ tst(scratch, Operand(String::kContainsCachedArrayIndexMask));
    EmitBranch(true_block, false_block, eq);
  }
  
  
  // Branches to a label or falls through with the answer in flags.  Trashes
  // the temp registers, but not the input.
  void LCodeGen::EmitClassOfTest(Label* is_true,
                                 Label* is_false,
                                 Handle<String>class_name,
                                 Register input,
                                 Register temp,
                                 Register temp2) {
    ASSERT(!input.is(temp));
    ASSERT(!input.is(temp2));
    ASSERT(!temp.is(temp2));
  
    __ JumpIfSmi(input, is_false);
  
    if (class_name->IsEqualTo(CStrVector("Function"))) {
      // Assuming the following assertions, we can use the same compares to test
      // for both being a function type and being in the object type range.
      STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
      STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                    FIRST_SPEC_OBJECT_TYPE + 1);
      STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                    LAST_SPEC_OBJECT_TYPE - 1);
      STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
      __ CompareObjectType(input, temp, temp2, FIRST_SPEC_OBJECT_TYPE);
      __ b(lt, is_false);
      __ b(eq, is_true);
      __ cmp(temp2, Operand(LAST_SPEC_OBJECT_TYPE));
      __ b(eq, is_true);
    } else {
      // Faster code path to avoid two compares: subtract lower bound from the
      // actual type and do a signed compare with the width of the type range.
      __ ldr(temp, FieldMemOperand(input, HeapObject::kMapOffset));
      __ ldrb(temp2, FieldMemOperand(temp, Map::kInstanceTypeOffset));
      __ sub(temp2, temp2, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
      __ cmp(temp2, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE -
                            FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
      __ b(gt, is_false);
    }
  
    // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
    // Check if the constructor in the map is a function.
    __ ldr(temp, FieldMemOperand(temp, Map::kConstructorOffset));
  
    // Objects with a non-function constructor have class 'Object'.
    __ CompareObjectType(temp, temp2, temp2, JS_FUNCTION_TYPE);
    if (class_name->IsEqualTo(CStrVector("Object"))) {
      __ b(ne, is_true);
    } else {
      __ b(ne, is_false);
    }
  
    // temp now contains the constructor function. Grab the
    // instance class name from there.
    __ ldr(temp, FieldMemOperand(temp, JSFunction::kSharedFunctionInfoOffset));
    __ ldr(temp, FieldMemOperand(temp,
                                 SharedFunctionInfo::kInstanceClassNameOffset));
    // The class name we are testing against is a symbol because it's a literal.
    // The name in the constructor is a symbol because of the way the context is
    // booted.  This routine isn't expected to work for random API-created
    // classes and it doesn't have to because you can't access it with natives
    // syntax.  Since both sides are symbols it is sufficient to use an identity
    // comparison.
    __ cmp(temp, Operand(class_name));
    // End with the answer in flags.
  }
  
  
  void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register temp = scratch0();
    Register temp2 = ToRegister(instr->TempAt(0));
    Handle<String> class_name = instr->hydrogen()->class_name();
  
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    Label* true_label = chunk_->GetAssemblyLabel(true_block);
    Label* false_label = chunk_->GetAssemblyLabel(false_block);
  
    EmitClassOfTest(true_label, false_label, class_name, input, temp, temp2);
  
    EmitBranch(true_block, false_block, eq);
  }
  
  
  void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
    Register reg = ToRegister(instr->InputAt(0));
    Register temp = ToRegister(instr->TempAt(0));
    int true_block = instr->true_block_id();
    int false_block = instr->false_block_id();
  
    __ ldr(temp, FieldMemOperand(reg, HeapObject::kMapOffset));
    __ cmp(temp, Operand(instr->map()));
    EmitBranch(true_block, false_block, eq);
  }
  
  
  void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
    ASSERT(ToRegister(instr->InputAt(0)).is(r0));  // Object is in r0.
    ASSERT(ToRegister(instr->InputAt(1)).is(r1));  // Function is in r1.
  
    InstanceofStub stub(InstanceofStub::kArgsInRegisters);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  
    __ cmp(r0, Operand(0));
    __ mov(r0, Operand(factory()->false_value()), LeaveCC, ne);
    __ mov(r0, Operand(factory()->true_value()), LeaveCC, 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_, &map_check_);
      }
      virtual LInstruction* instr() { return instr_; }
      Label* map_check() { return &map_check_; }
     private:
      LInstanceOfKnownGlobal* instr_;
      Label map_check_;
    };
  
    DeferredInstanceOfKnownGlobal* deferred;
    deferred = new DeferredInstanceOfKnownGlobal(this, instr);
  
    Label done, false_result;
    Register object = ToRegister(instr->InputAt(0));
    Register temp = ToRegister(instr->TempAt(0));
    Register result = ToRegister(instr->result());
  
    ASSERT(object.is(r0));
    ASSERT(result.is(r0));
  
    // A Smi is not instance of anything.
    __ JumpIfSmi(object, &false_result);
  
    // This is the inlined call site instanceof cache. The two occurences of the
    // hole value will be patched to the last map/result pair generated by the
    // instanceof stub.
    Label cache_miss;
    Register map = temp;
    __ ldr(map, FieldMemOperand(object, HeapObject::kMapOffset));
    __ bind(deferred->map_check());  // Label for calculating code patching.
    // We use Factory::the_hole_value() on purpose instead of loading from the
    // root array to force relocation to be able to later patch with
    // the cached map.
    Handle<JSGlobalPropertyCell> cell =
        factory()->NewJSGlobalPropertyCell(factory()->the_hole_value());
    __ mov(ip, Operand(Handle<Object>(cell)));
    __ ldr(ip, FieldMemOperand(ip, JSGlobalPropertyCell::kValueOffset));
    __ cmp(map, Operand(ip));
    __ b(ne, &cache_miss);
    // We use Factory::the_hole_value() on purpose instead of loading from the
    // root array to force relocation to be able to later patch
    // with true or false.
    __ mov(result, Operand(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);
    // Null is not instance of anything.
    __ LoadRoot(ip, Heap::kNullValueRootIndex);
    __ cmp(object, Operand(ip));
    __ b(eq, &false_result);
  
    // String values is not instance of anything.
    Condition is_string = masm_->IsObjectStringType(object, temp);
    __ b(is_string, &false_result);
  
    // Go to the deferred code.
    __ b(deferred->entry());
  
    __ bind(&false_result);
    __ LoadRoot(result, Heap::kFalseValueRootIndex);
  
    // Here result has either true or false. Deferred code also produces true or
    // false object.
    __ bind(deferred->exit());
    __ bind(&done);
  }
  
  
  void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
                                                 Label* map_check) {
    Register result = ToRegister(instr->result());
    ASSERT(result.is(r0));
  
    InstanceofStub::Flags flags = InstanceofStub::kNoFlags;
    flags = static_cast<InstanceofStub::Flags>(
        flags | InstanceofStub::kArgsInRegisters);
    flags = static_cast<InstanceofStub::Flags>(
        flags | InstanceofStub::kCallSiteInlineCheck);
    flags = static_cast<InstanceofStub::Flags>(
        flags | InstanceofStub::kReturnTrueFalseObject);
    InstanceofStub stub(flags);
  
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
  
    // Get the temp register reserved by the instruction. This needs to be r4 as
    // its slot of the pushing of safepoint registers is used to communicate the
    // offset to the location of the map check.
    Register temp = ToRegister(instr->TempAt(0));
    ASSERT(temp.is(r4));
    __ LoadHeapObject(InstanceofStub::right(), instr->function());
    static const int kAdditionalDelta = 4;
    int delta = masm_->InstructionsGeneratedSince(map_check) + kAdditionalDelta;
    Label before_push_delta;
    __ bind(&before_push_delta);
    __ BlockConstPoolFor(kAdditionalDelta);
    __ mov(temp, Operand(delta * kPointerSize));
    __ StoreToSafepointRegisterSlot(temp, temp);
    CallCodeGeneric(stub.GetCode(),
                    RelocInfo::CODE_TARGET,
                    instr,
                    RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
    ASSERT(instr->HasDeoptimizationEnvironment());
    LEnvironment* env = instr->deoptimization_environment();
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
    // Put the result value into the result register slot and
    // restore all registers.
    __ StoreToSafepointRegisterSlot(result, result);
  }
  
  
  void LCodeGen::DoCmpT(LCmpT* instr) {
    Token::Value op = instr->op();
  
    Handle<Code> ic = CompareIC::GetUninitialized(op);
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
    __ cmp(r0, Operand(0));  // This instruction also signals no smi code inlined.
  
    Condition condition = ComputeCompareCondition(op);
    __ LoadRoot(ToRegister(instr->result()),
                Heap::kTrueValueRootIndex,
                condition);
    __ LoadRoot(ToRegister(instr->result()),
                Heap::kFalseValueRootIndex,
                NegateCondition(condition));
  }
  
  
  void LCodeGen::DoReturn(LReturn* instr) {
    if (FLAG_trace) {
      // Push the return value on the stack as the parameter.
      // Runtime::TraceExit returns its parameter in r0.
      __ push(r0);
      __ CallRuntime(Runtime::kTraceExit, 1);
    }
    int32_t sp_delta = (GetParameterCount() + 1) * kPointerSize;
    __ mov(sp, fp);
    __ ldm(ia_w, sp, fp.bit() | lr.bit());
    __ add(sp, sp, Operand(sp_delta));
    __ Jump(lr);
  }
  
  
  void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
    Register result = ToRegister(instr->result());
    __ mov(ip, Operand(Handle<Object>(instr->hydrogen()->cell())));
    __ ldr(result, FieldMemOperand(ip, JSGlobalPropertyCell::kValueOffset));
    if (instr->hydrogen()->RequiresHoleCheck()) {
      __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
      __ cmp(result, ip);
      DeoptimizeIf(eq, instr->environment());
    }
  }
  
  
  void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
    ASSERT(ToRegister(instr->global_object()).is(r0));
    ASSERT(ToRegister(instr->result()).is(r0));
  
    __ mov(r2, Operand(instr->name()));
    RelocInfo::Mode mode = instr->for_typeof() ? RelocInfo::CODE_TARGET
                                               : RelocInfo::CODE_TARGET_CONTEXT;
    Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
    CallCode(ic, mode, instr);
  }
  
  
  void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
    Register value = ToRegister(instr->value());
    Register cell = scratch0();
  
    // Load the cell.
    __ mov(cell, Operand(instr->hydrogen()->cell()));
  
    // If the cell we are storing to contains the hole it could have
    // been deleted from the property dictionary. In that case, we need
    // to update the property details in the property dictionary to mark
    // it as no longer deleted.
    if (instr->hydrogen()->RequiresHoleCheck()) {
      // We use a temp to check the payload (CompareRoot might clobber ip).
      Register payload = ToRegister(instr->TempAt(0));
      __ ldr(payload, FieldMemOperand(cell, JSGlobalPropertyCell::kValueOffset));
      __ CompareRoot(payload, Heap::kTheHoleValueRootIndex);
      DeoptimizeIf(eq, instr->environment());
    }
  
    // Store the value.
    __ str(value, FieldMemOperand(cell, JSGlobalPropertyCell::kValueOffset));
    // Cells are always rescanned, so no write barrier here.
  }
  
  
  void LCodeGen::DoStoreGlobalGeneric(LStoreGlobalGeneric* instr) {
    ASSERT(ToRegister(instr->global_object()).is(r1));
    ASSERT(ToRegister(instr->value()).is(r0));
  
    __ mov(r2, Operand(instr->name()));
    Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
        ? isolate()->builtins()->StoreIC_Initialize_Strict()
        : isolate()->builtins()->StoreIC_Initialize();
    CallCode(ic, RelocInfo::CODE_TARGET_CONTEXT, instr);
  }
  
  
  void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
    Register context = ToRegister(instr->context());
    Register result = ToRegister(instr->result());
    __ ldr(result, ContextOperand(context, instr->slot_index()));
    if (instr->hydrogen()->RequiresHoleCheck()) {
      __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
      __ cmp(result, ip);
      if (instr->hydrogen()->DeoptimizesOnHole()) {
        DeoptimizeIf(eq, instr->environment());
      } else {
        __ mov(result, Operand(factory()->undefined_value()), LeaveCC, eq);
      }
    }
  }
  
  
  void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
    Register context = ToRegister(instr->context());
    Register value = ToRegister(instr->value());
    Register scratch = scratch0();
    MemOperand target = ContextOperand(context, instr->slot_index());
  
    Label skip_assignment;
  
    if (instr->hydrogen()->RequiresHoleCheck()) {
      __ ldr(scratch, target);
      __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
      __ cmp(scratch, ip);
      if (instr->hydrogen()->DeoptimizesOnHole()) {
        DeoptimizeIf(eq, instr->environment());
      } else {
        __ b(ne, &skip_assignment);
      }
    }
  
    __ str(value, target);
    if (instr->hydrogen()->NeedsWriteBarrier()) {
      HType type = instr->hydrogen()->value()->type();
      SmiCheck check_needed =
          type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
      __ RecordWriteContextSlot(context,
                                target.offset(),
                                value,
                                scratch,
                                kLRHasBeenSaved,
                                kSaveFPRegs,
                                EMIT_REMEMBERED_SET,
                                check_needed);
    }
  
    __ bind(&skip_assignment);
  }
  
  
  void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
    Register object = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    if (instr->hydrogen()->is_in_object()) {
      __ ldr(result, FieldMemOperand(object, instr->hydrogen()->offset()));
    } else {
      __ ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
      __ ldr(result, FieldMemOperand(result, instr->hydrogen()->offset()));
    }
  }
  
  
  void LCodeGen::EmitLoadFieldOrConstantFunction(Register result,
                                                 Register object,
                                                 Handle<Map> type,
                                                 Handle<String> name) {
    LookupResult lookup(isolate());
    type->LookupInDescriptors(NULL, *name, &lookup);
    ASSERT(lookup.IsFound() &&
           (lookup.type() == FIELD || lookup.type() == CONSTANT_FUNCTION));
    if (lookup.type() == FIELD) {
      int index = lookup.GetLocalFieldIndexFromMap(*type);
      int offset = index * kPointerSize;
      if (index < 0) {
        // Negative property indices are in-object properties, indexed
        // from the end of the fixed part of the object.
        __ ldr(result, FieldMemOperand(object, offset + type->instance_size()));
      } else {
        // Non-negative property indices are in the properties array.
        __ ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
        __ ldr(result, FieldMemOperand(result, offset + FixedArray::kHeaderSize));
      }
    } else {
      Handle<JSFunction> function(lookup.GetConstantFunctionFromMap(*type));
      __ LoadHeapObject(result, function);
    }
  }
  
  
  void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
    Register object = ToRegister(instr->object());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
    int map_count = instr->hydrogen()->types()->length();
    Handle<String> name = instr->hydrogen()->name();
    if (map_count == 0) {
      ASSERT(instr->hydrogen()->need_generic());
      __ mov(r2, Operand(name));
      Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
      CallCode(ic, RelocInfo::CODE_TARGET, instr);
    } else {
      Label done;
      __ ldr(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
      for (int i = 0; i < map_count - 1; ++i) {
        Handle<Map> map = instr->hydrogen()->types()->at(i);
        Label next;
        __ cmp(scratch, Operand(map));
        __ b(ne, &next);
        EmitLoadFieldOrConstantFunction(result, object, map, name);
        __ b(&done);
        __ bind(&next);
      }
      Handle<Map> map = instr->hydrogen()->types()->last();
      __ cmp(scratch, Operand(map));
      if (instr->hydrogen()->need_generic()) {
        Label generic;
        __ b(ne, &generic);
        EmitLoadFieldOrConstantFunction(result, object, map, name);
        __ b(&done);
        __ bind(&generic);
        __ mov(r2, Operand(name));
        Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
        CallCode(ic, RelocInfo::CODE_TARGET, instr);
      } else {
        DeoptimizeIf(ne, instr->environment());
        EmitLoadFieldOrConstantFunction(result, object, map, name);
      }
      __ bind(&done);
    }
  }
  
  
  void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
    ASSERT(ToRegister(instr->object()).is(r0));
    ASSERT(ToRegister(instr->result()).is(r0));
  
    // Name is always in r2.
    __ mov(r2, Operand(instr->name()));
    Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
    Register scratch = scratch0();
    Register function = ToRegister(instr->function());
    Register result = ToRegister(instr->result());
  
    // Check that the function really is a function. Load map into the
    // result register.
    __ CompareObjectType(function, result, scratch, JS_FUNCTION_TYPE);
    DeoptimizeIf(ne, instr->environment());
  
    // Make sure that the function has an instance prototype.
    Label non_instance;
    __ ldrb(scratch, FieldMemOperand(result, Map::kBitFieldOffset));
    __ tst(scratch, Operand(1 << Map::kHasNonInstancePrototype));
    __ b(ne, &non_instance);
  
    // 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.
    __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
    __ cmp(result, ip);
    DeoptimizeIf(eq, instr->environment());
  
    // If the function does not have an initial map, we're done.
    Label done;
    __ CompareObjectType(result, scratch, scratch, MAP_TYPE);
    __ b(ne, &done);
  
    // Get the prototype from the initial map.
    __ ldr(result, FieldMemOperand(result, Map::kPrototypeOffset));
    __ jmp(&done);
  
    // Non-instance prototype: Fetch prototype from constructor field
    // in initial map.
    __ bind(&non_instance);
    __ ldr(result, FieldMemOperand(result, Map::kConstructorOffset));
  
    // All done.
    __ bind(&done);
  }
  
  
  void LCodeGen::DoLoadElements(LLoadElements* instr) {
    Register result = ToRegister(instr->result());
    Register input = ToRegister(instr->InputAt(0));
    Register scratch = scratch0();
  
    __ ldr(result, FieldMemOperand(input, JSObject::kElementsOffset));
    if (FLAG_debug_code) {
      Label done, fail;
      __ ldr(scratch, FieldMemOperand(result, HeapObject::kMapOffset));
      __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
      __ cmp(scratch, ip);
      __ b(eq, &done);
      __ LoadRoot(ip, Heap::kFixedCOWArrayMapRootIndex);
      __ cmp(scratch, ip);
      __ b(eq, &done);
      // |scratch| still contains |input|'s map.
      __ ldr(scratch, FieldMemOperand(scratch, Map::kBitField2Offset));
      __ ubfx(scratch, scratch, Map::kElementsKindShift,
              Map::kElementsKindBitCount);
      __ cmp(scratch, Operand(FAST_ELEMENTS));
      __ b(eq, &done);
      __ cmp(scratch, Operand(FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND));
      __ b(lt, &fail);
      __ cmp(scratch, Operand(LAST_EXTERNAL_ARRAY_ELEMENTS_KIND));
      __ b(le, &done);
      __ bind(&fail);
      __ Abort("Check for fast or external elements failed.");
      __ bind(&done);
    }
  }
  
  
  void LCodeGen::DoLoadExternalArrayPointer(
      LLoadExternalArrayPointer* instr) {
    Register to_reg = ToRegister(instr->result());
    Register from_reg  = ToRegister(instr->InputAt(0));
    __ ldr(to_reg, FieldMemOperand(from_reg,
                                   ExternalArray::kExternalPointerOffset));
  }
  
  
  void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
    Register arguments = ToRegister(instr->arguments());
    Register length = ToRegister(instr->length());
    Register index = ToRegister(instr->index());
    Register result = ToRegister(instr->result());
  
    // Bailout index is not a valid argument index. Use unsigned check to get
    // negative check for free.
    __ sub(length, length, index, SetCC);
    DeoptimizeIf(ls, instr->environment());
  
    // There are two words between the frame pointer and the last argument.
    // Subtracting from length accounts for one of them add one more.
    __ add(length, length, Operand(1));
    __ ldr(result, MemOperand(arguments, length, LSL, kPointerSizeLog2));
  }
  
  
  void LCodeGen::DoLoadKeyedFastElement(LLoadKeyedFastElement* instr) {
    Register elements = ToRegister(instr->elements());
    Register key = EmitLoadRegister(instr->key(), scratch0());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
  
    // Load the result.
    __ add(scratch, elements, Operand(key, LSL, kPointerSizeLog2));
    __ ldr(result, FieldMemOperand(scratch, FixedArray::kHeaderSize));
  
    // Check for the hole value.
    if (instr->hydrogen()->RequiresHoleCheck()) {
      __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
      __ cmp(result, scratch);
      DeoptimizeIf(eq, instr->environment());
    }
  }
  
  
  void LCodeGen::DoLoadKeyedFastDoubleElement(
      LLoadKeyedFastDoubleElement* instr) {
    Register elements = ToRegister(instr->elements());
    bool key_is_constant = instr->key()->IsConstantOperand();
    Register key = no_reg;
    DwVfpRegister result = ToDoubleRegister(instr->result());
    Register scratch = scratch0();
  
    int shift_size =
        ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
    int constant_key = 0;
    if (key_is_constant) {
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xF0000000) {
        Abort("array index constant value too big.");
      }
    } else {
      key = ToRegister(instr->key());
    }
  
    Operand operand = key_is_constant
        ? Operand(constant_key * (1 << shift_size) +
                  FixedDoubleArray::kHeaderSize - kHeapObjectTag)
        : Operand(key, LSL, shift_size);
    __ add(elements, elements, operand);
    if (!key_is_constant) {
      __ add(elements, elements,
             Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
    }
  
    __ ldr(scratch, MemOperand(elements, sizeof(kHoleNanLower32)));
    __ cmp(scratch, Operand(kHoleNanUpper32));
    DeoptimizeIf(eq, instr->environment());
  
    __ vldr(result, elements, 0);
  }
  
  
  void LCodeGen::DoLoadKeyedSpecializedArrayElement(
      LLoadKeyedSpecializedArrayElement* instr) {
    Register external_pointer = ToRegister(instr->external_pointer());
    Register key = no_reg;
    ElementsKind elements_kind = instr->elements_kind();
    bool key_is_constant = instr->key()->IsConstantOperand();
    int constant_key = 0;
    if (key_is_constant) {
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xF0000000) {
        Abort("array index constant value too big.");
      }
    } else {
      key = ToRegister(instr->key());
    }
    int shift_size = ElementsKindToShiftSize(elements_kind);
  
    if (elements_kind == EXTERNAL_FLOAT_ELEMENTS ||
        elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
      CpuFeatures::Scope scope(VFP3);
      DwVfpRegister result = ToDoubleRegister(instr->result());
      Operand operand = key_is_constant
          ? Operand(constant_key * (1 << shift_size))
          : Operand(key, LSL, shift_size);
      __ add(scratch0(), external_pointer, operand);
      if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
        __ vldr(result.low(), scratch0(), 0);
        __ vcvt_f64_f32(result, result.low());
      } else  {  // i.e. elements_kind == EXTERNAL_DOUBLE_ELEMENTS
        __ vldr(result, scratch0(), 0);
      }
    } else {
      Register result = ToRegister(instr->result());
      MemOperand mem_operand(key_is_constant
          ? MemOperand(external_pointer, constant_key * (1 << shift_size))
          : MemOperand(external_pointer, key, LSL, shift_size));
      switch (elements_kind) {
        case EXTERNAL_BYTE_ELEMENTS:
          __ ldrsb(result, mem_operand);
          break;
        case EXTERNAL_PIXEL_ELEMENTS:
        case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
          __ ldrb(result, mem_operand);
          break;
        case EXTERNAL_SHORT_ELEMENTS:
          __ ldrsh(result, mem_operand);
          break;
        case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
          __ ldrh(result, mem_operand);
          break;
        case EXTERNAL_INT_ELEMENTS:
          __ ldr(result, mem_operand);
          break;
        case EXTERNAL_UNSIGNED_INT_ELEMENTS:
          __ ldr(result, mem_operand);
          __ cmp(result, Operand(0x80000000));
          // TODO(danno): we could be more clever here, perhaps having a special
          // version of the stub that detects if the overflow case actually
          // happens, and generate code that returns a double rather than int.
          DeoptimizeIf(cs, instr->environment());
          break;
        case EXTERNAL_FLOAT_ELEMENTS:
        case EXTERNAL_DOUBLE_ELEMENTS:
        case FAST_DOUBLE_ELEMENTS:
        case FAST_ELEMENTS:
        case FAST_SMI_ONLY_ELEMENTS:
        case DICTIONARY_ELEMENTS:
        case NON_STRICT_ARGUMENTS_ELEMENTS:
          UNREACHABLE();
          break;
      }
    }
  }
  
  
  void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
    ASSERT(ToRegister(instr->object()).is(r1));
    ASSERT(ToRegister(instr->key()).is(r0));
  
    Handle<Code> ic = isolate()->builtins()->KeyedLoadIC_Initialize();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
    Register scratch = scratch0();
    Register result = ToRegister(instr->result());
  
    // Check if the calling frame is an arguments adaptor frame.
    Label done, adapted;
    __ ldr(scratch, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ ldr(result, MemOperand(scratch, StandardFrameConstants::kContextOffset));
    __ cmp(result, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
  
    // Result is the frame pointer for the frame if not adapted and for the real
    // frame below the adaptor frame if adapted.
    __ mov(result, fp, LeaveCC, ne);
    __ mov(result, scratch, LeaveCC, eq);
  }
  
  
  void LCodeGen::DoArgumentsLength(LArgumentsLength* instr) {
    Register elem = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
  
    Label done;
  
    // If no arguments adaptor frame the number of arguments is fixed.
    __ cmp(fp, elem);
    __ mov(result, Operand(scope()->num_parameters()));
    __ b(eq, &done);
  
    // Arguments adaptor frame present. Get argument length from there.
    __ ldr(result, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ ldr(result,
           MemOperand(result, ArgumentsAdaptorFrameConstants::kLengthOffset));
    __ SmiUntag(result);
  
    // Argument length is in result register.
    __ bind(&done);
  }
  
  
  void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
    Register receiver = ToRegister(instr->receiver());
    Register function = ToRegister(instr->function());
    Register scratch = scratch0();
  
    // If the receiver is null or undefined, we have to pass the global
    // object as a receiver to normal functions. Values have to be
    // passed unchanged to builtins and strict-mode functions.
    Label global_object, receiver_ok;
  
    // Do not transform the receiver to object for strict mode
    // functions.
    __ ldr(scratch,
           FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
    __ ldr(scratch,
           FieldMemOperand(scratch, SharedFunctionInfo::kCompilerHintsOffset));
    __ tst(scratch,
           Operand(1 << (SharedFunctionInfo::kStrictModeFunction + kSmiTagSize)));
    __ b(ne, &receiver_ok);
  
    // Do not transform the receiver to object for builtins.
    __ tst(scratch, Operand(1 << (SharedFunctionInfo::kNative + kSmiTagSize)));
    __ b(ne, &receiver_ok);
  
    // Normal function. Replace undefined or null with global receiver.
    __ LoadRoot(scratch, Heap::kNullValueRootIndex);
    __ cmp(receiver, scratch);
    __ b(eq, &global_object);
    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
    __ cmp(receiver, scratch);
    __ b(eq, &global_object);
  
    // Deoptimize if the receiver is not a JS object.
    __ tst(receiver, Operand(kSmiTagMask));
    DeoptimizeIf(eq, instr->environment());
    __ CompareObjectType(receiver, scratch, scratch, FIRST_SPEC_OBJECT_TYPE);
    DeoptimizeIf(lt, instr->environment());
    __ jmp(&receiver_ok);
  
    __ bind(&global_object);
    __ ldr(receiver, GlobalObjectOperand());
    __ ldr(receiver,
           FieldMemOperand(receiver, JSGlobalObject::kGlobalReceiverOffset));
    __ bind(&receiver_ok);
  }
  
  
  void LCodeGen::DoApplyArguments(LApplyArguments* instr) {
    Register receiver = ToRegister(instr->receiver());
    Register function = ToRegister(instr->function());
    Register length = ToRegister(instr->length());
    Register elements = ToRegister(instr->elements());
    Register scratch = scratch0();
    ASSERT(receiver.is(r0));  // Used for parameter count.
    ASSERT(function.is(r1));  // Required by InvokeFunction.
    ASSERT(ToRegister(instr->result()).is(r0));
  
    // Copy the arguments to this function possibly from the
    // adaptor frame below it.
    const uint32_t kArgumentsLimit = 1 * KB;
    __ cmp(length, Operand(kArgumentsLimit));
    DeoptimizeIf(hi, instr->environment());
  
    // Push the receiver and use the register to keep the original
    // number of arguments.
    __ push(receiver);
    __ mov(receiver, length);
    // The arguments are at a one pointer size offset from elements.
    __ add(elements, elements, Operand(1 * kPointerSize));
  
    // Loop through the arguments pushing them onto the execution
    // stack.
    Label invoke, loop;
    // length is a small non-negative integer, due to the test above.
    __ cmp(length, Operand(0));
    __ b(eq, &invoke);
    __ bind(&loop);
    __ ldr(scratch, MemOperand(elements, length, LSL, 2));
    __ push(scratch);
    __ sub(length, length, Operand(1), SetCC);
    __ b(ne, &loop);
  
    __ bind(&invoke);
    ASSERT(instr->HasPointerMap() && instr->HasDeoptimizationEnvironment());
    LPointerMap* pointers = instr->pointer_map();
    RecordPosition(pointers->position());
    SafepointGenerator safepoint_generator(
        this, pointers, Safepoint::kLazyDeopt);
    // The number of arguments is stored in receiver which is r0, as expected
    // by InvokeFunction.
    ParameterCount actual(receiver);
    __ InvokeFunction(function, actual, CALL_FUNCTION,
                      safepoint_generator, CALL_AS_METHOD);
    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoPushArgument(LPushArgument* instr) {
    LOperand* argument = instr->InputAt(0);
    if (argument->IsDoubleRegister() || argument->IsDoubleStackSlot()) {
      Abort("DoPushArgument not implemented for double type.");
    } else {
      Register argument_reg = EmitLoadRegister(argument, ip);
      __ push(argument_reg);
    }
  }
  
  
  void LCodeGen::DoThisFunction(LThisFunction* instr) {
    Register result = ToRegister(instr->result());
    __ LoadHeapObject(result, instr->hydrogen()->closure());
  }
  
  
  void LCodeGen::DoContext(LContext* instr) {
    Register result = ToRegister(instr->result());
    __ mov(result, cp);
  }
  
  
  void LCodeGen::DoOuterContext(LOuterContext* instr) {
    Register context = ToRegister(instr->context());
    Register result = ToRegister(instr->result());
    __ ldr(result,
           MemOperand(context, Context::SlotOffset(Context::PREVIOUS_INDEX)));
  }
  
  
  void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
    __ push(cp);  // The context is the first argument.
    __ LoadHeapObject(scratch0(), instr->hydrogen()->pairs());
    __ push(scratch0());
    __ mov(scratch0(), Operand(Smi::FromInt(instr->hydrogen()->flags())));
    __ push(scratch0());
    CallRuntime(Runtime::kDeclareGlobals, 3, instr);
  }
  
  
  void LCodeGen::DoGlobalObject(LGlobalObject* instr) {
    Register result = ToRegister(instr->result());
    __ ldr(result, ContextOperand(cp, Context::GLOBAL_INDEX));
  }
  
  
  void LCodeGen::DoGlobalReceiver(LGlobalReceiver* instr) {
    Register global = ToRegister(instr->global());
    Register result = ToRegister(instr->result());
    __ ldr(result, FieldMemOperand(global, GlobalObject::kGlobalReceiverOffset));
  }
  
  
  void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
                                   int arity,
                                   LInstruction* instr,
                                   CallKind call_kind) {
    bool can_invoke_directly = !function->NeedsArgumentsAdaption() ||
        function->shared()->formal_parameter_count() == arity;
  
    LPointerMap* pointers = instr->pointer_map();
    RecordPosition(pointers->position());
  
    if (can_invoke_directly) {
      __ LoadHeapObject(r1, function);
      // Change context if needed.
      bool change_context =
          (info()->closure()->context() != function->context()) ||
          scope()->contains_with() ||
          (scope()->num_heap_slots() > 0);
      if (change_context) {
        __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
      }
  
      // Set r0 to arguments count if adaption is not needed. Assumes that r0
      // is available to write to at this point.
      if (!function->NeedsArgumentsAdaption()) {
        __ mov(r0, Operand(arity));
      }
  
      // Invoke function.
      __ SetCallKind(r5, call_kind);
      __ ldr(ip, FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
      __ Call(ip);
  
      // Set up deoptimization.
      RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
    } else {
      SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
      ParameterCount count(arity);
      __ InvokeFunction(function, count, CALL_FUNCTION, generator, call_kind);
    }
  
    // Restore context.
    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoCallConstantFunction(LCallConstantFunction* instr) {
    ASSERT(ToRegister(instr->result()).is(r0));
    CallKnownFunction(instr->function(),
                      instr->arity(),
                      instr,
                      CALL_AS_METHOD);
  }
  
  
  void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LUnaryMathOperation* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
  
    // Deoptimize if not a heap number.
    __ ldr(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
    __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
    __ cmp(scratch, Operand(ip));
    DeoptimizeIf(ne, instr->environment());
  
    Label done;
    Register exponent = scratch0();
    scratch = no_reg;
    __ ldr(exponent, FieldMemOperand(input, HeapNumber::kExponentOffset));
    // Check the sign of the argument. If the argument is positive, just
    // return it.
    __ tst(exponent, Operand(HeapNumber::kSignMask));
    // Move the input to the result if necessary.
    __ Move(result, input);
    __ b(eq, &done);
  
    // Input is negative. Reverse its sign.
    // Preserve the value of all registers.
    {
      PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
  
      // Registers were saved at the safepoint, so we can use
      // many scratch registers.
      Register tmp1 = input.is(r1) ? r0 : r1;
      Register tmp2 = input.is(r2) ? r0 : r2;
      Register tmp3 = input.is(r3) ? r0 : r3;
      Register tmp4 = input.is(r4) ? r0 : r4;
  
      // exponent: floating point exponent value.
  
      Label allocated, slow;
      __ LoadRoot(tmp4, Heap::kHeapNumberMapRootIndex);
      __ AllocateHeapNumber(tmp1, tmp2, tmp3, tmp4, &slow);
      __ b(&allocated);
  
      // Slow case: Call the runtime system to do the number allocation.
      __ bind(&slow);
  
      CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
      // Set the pointer to the new heap number in tmp.
      if (!tmp1.is(r0)) __ mov(tmp1, Operand(r0));
      // Restore input_reg after call to runtime.
      __ LoadFromSafepointRegisterSlot(input, input);
      __ ldr(exponent, FieldMemOperand(input, HeapNumber::kExponentOffset));
  
      __ bind(&allocated);
      // exponent: floating point exponent value.
      // tmp1: allocated heap number.
      __ bic(exponent, exponent, Operand(HeapNumber::kSignMask));
      __ str(exponent, FieldMemOperand(tmp1, HeapNumber::kExponentOffset));
      __ ldr(tmp2, FieldMemOperand(input, HeapNumber::kMantissaOffset));
      __ str(tmp2, FieldMemOperand(tmp1, HeapNumber::kMantissaOffset));
  
      __ StoreToSafepointRegisterSlot(tmp1, result);
    }
  
    __ bind(&done);
  }
  
  
  void LCodeGen::EmitIntegerMathAbs(LUnaryMathOperation* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    __ cmp(input, Operand(0));
    __ Move(result, input, pl);
    // We can make rsb conditional because the previous cmp instruction
    // will clear the V (overflow) flag and rsb won't set this flag
    // if input is positive.
    __ rsb(result, input, Operand(0), SetCC, mi);
    // Deoptimize on overflow.
    DeoptimizeIf(vs, instr->environment());
  }
  
  
  void LCodeGen::DoMathAbs(LUnaryMathOperation* instr) {
    // Class for deferred case.
    class DeferredMathAbsTaggedHeapNumber: public LDeferredCode {
     public:
      DeferredMathAbsTaggedHeapNumber(LCodeGen* codegen,
                                      LUnaryMathOperation* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() {
        codegen()->DoDeferredMathAbsTaggedHeapNumber(instr_);
      }
      virtual LInstruction* instr() { return instr_; }
     private:
      LUnaryMathOperation* instr_;
    };
  
    Representation r = instr->hydrogen()->value()->representation();
    if (r.IsDouble()) {
      DwVfpRegister input = ToDoubleRegister(instr->InputAt(0));
      DwVfpRegister result = ToDoubleRegister(instr->result());
      __ vabs(result, input);
    } else if (r.IsInteger32()) {
      EmitIntegerMathAbs(instr);
    } else {
      // Representation is tagged.
      DeferredMathAbsTaggedHeapNumber* deferred =
          new DeferredMathAbsTaggedHeapNumber(this, instr);
      Register input = ToRegister(instr->InputAt(0));
      // Smi check.
      __ JumpIfNotSmi(input, deferred->entry());
      // If smi, handle it directly.
      EmitIntegerMathAbs(instr);
      __ bind(deferred->exit());
    }
  }
  
  
  void LCodeGen::DoMathFloor(LUnaryMathOperation* instr) {
    DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    SwVfpRegister single_scratch = double_scratch0().low();
    Register scratch1 = scratch0();
    Register scratch2 = ToRegister(instr->TempAt(0));
  
    __ EmitVFPTruncate(kRoundToMinusInf,
                       single_scratch,
                       input,
                       scratch1,
                       scratch2);
    DeoptimizeIf(ne, instr->environment());
  
    // Move the result back to general purpose register r0.
    __ vmov(result, single_scratch);
  
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      // Test for -0.
      Label done;
      __ cmp(result, Operand(0));
      __ b(ne, &done);
      __ vmov(scratch1, input.high());
      __ tst(scratch1, Operand(HeapNumber::kSignMask));
      DeoptimizeIf(ne, instr->environment());
      __ bind(&done);
    }
  }
  
  
  void LCodeGen::DoMathRound(LUnaryMathOperation* instr) {
    DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
    Label done, check_sign_on_zero;
  
    // Extract exponent bits.
    __ vmov(result, input.high());
    __ ubfx(scratch,
            result,
            HeapNumber::kExponentShift,
            HeapNumber::kExponentBits);
  
    // If the number is in ]-0.5, +0.5[, the result is +/- 0.
    __ cmp(scratch, Operand(HeapNumber::kExponentBias - 2));
    __ mov(result, Operand(0), LeaveCC, le);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ b(le, &check_sign_on_zero);
    } else {
      __ b(le, &done);
    }
  
    // The following conversion will not work with numbers
    // outside of ]-2^32, 2^32[.
    __ cmp(scratch, Operand(HeapNumber::kExponentBias + 32));
    DeoptimizeIf(ge, instr->environment());
  
    // Save the original sign for later comparison.
    __ and_(scratch, result, Operand(HeapNumber::kSignMask));
  
    __ Vmov(double_scratch0(), 0.5);
    __ vadd(double_scratch0(), input, double_scratch0());
  
    // Check sign of the result: if the sign changed, the input
    // value was in ]0.5, 0[ and the result should be -0.
    __ vmov(result, double_scratch0().high());
    __ eor(result, result, Operand(scratch), SetCC);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIf(mi, instr->environment());
    } else {
      __ mov(result, Operand(0), LeaveCC, mi);
      __ b(mi, &done);
    }
  
    __ EmitVFPTruncate(kRoundToMinusInf,
                       double_scratch0().low(),
                       double_scratch0(),
                       result,
                       scratch);
    DeoptimizeIf(ne, instr->environment());
    __ vmov(result, double_scratch0().low());
  
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      // Test for -0.
      __ cmp(result, Operand(0));
      __ b(ne, &done);
      __ bind(&check_sign_on_zero);
      __ vmov(scratch, input.high());
      __ tst(scratch, Operand(HeapNumber::kSignMask));
      DeoptimizeIf(ne, instr->environment());
    }
    __ bind(&done);
  }
  
  
  void LCodeGen::DoMathSqrt(LUnaryMathOperation* instr) {
    DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
    DoubleRegister result = ToDoubleRegister(instr->result());
    __ vsqrt(result, input);
  }
  
  
  void LCodeGen::DoMathPowHalf(LUnaryMathOperation* instr) {
    DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
    DoubleRegister result = ToDoubleRegister(instr->result());
    DoubleRegister temp = ToDoubleRegister(instr->TempAt(0));
  
    // Note that according to ECMA-262 15.8.2.13:
    // Math.pow(-Infinity, 0.5) == Infinity
    // Math.sqrt(-Infinity) == NaN
    Label done;
    __ vmov(temp, -V8_INFINITY);
    __ VFPCompareAndSetFlags(input, temp);
    __ vneg(result, temp, eq);
    __ b(&done, eq);
  
    // Add +0 to convert -0 to +0.
    __ vadd(result, input, kDoubleRegZero);
    __ vsqrt(result, result);
    __ bind(&done);
  }
  
  
  void LCodeGen::DoPower(LPower* instr) {
    Representation exponent_type = instr->hydrogen()->right()->representation();
    // Having marked this as a call, we can use any registers.
    // Just make sure that the input/output registers are the expected ones.
    ASSERT(!instr->InputAt(1)->IsDoubleRegister() ||
           ToDoubleRegister(instr->InputAt(1)).is(d2));
    ASSERT(!instr->InputAt(1)->IsRegister() ||
           ToRegister(instr->InputAt(1)).is(r2));
    ASSERT(ToDoubleRegister(instr->InputAt(0)).is(d1));
    ASSERT(ToDoubleRegister(instr->result()).is(d3));
  
    if (exponent_type.IsTagged()) {
      Label no_deopt;
      __ JumpIfSmi(r2, &no_deopt);
      __ ldr(r7, FieldMemOperand(r2, HeapObject::kMapOffset));
      __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
      __ cmp(r7, Operand(ip));
      DeoptimizeIf(ne, instr->environment());
      __ bind(&no_deopt);
      MathPowStub stub(MathPowStub::TAGGED);
      __ CallStub(&stub);
    } else if (exponent_type.IsInteger32()) {
      MathPowStub stub(MathPowStub::INTEGER);
      __ CallStub(&stub);
    } else {
      ASSERT(exponent_type.IsDouble());
      MathPowStub stub(MathPowStub::DOUBLE);
      __ CallStub(&stub);
    }
  }
  
  
  void LCodeGen::DoRandom(LRandom* instr) {
    class DeferredDoRandom: public LDeferredCode {
     public:
      DeferredDoRandom(LCodeGen* codegen, LRandom* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() { codegen()->DoDeferredRandom(instr_); }
      virtual LInstruction* instr() { return instr_; }
     private:
      LRandom* instr_;
    };
  
    DeferredDoRandom* deferred = new DeferredDoRandom(this, instr);
  
    // Having marked this instruction as a call we can use any
    // registers.
    ASSERT(ToDoubleRegister(instr->result()).is(d7));
    ASSERT(ToRegister(instr->InputAt(0)).is(r0));
  
    static const int kSeedSize = sizeof(uint32_t);
    STATIC_ASSERT(kPointerSize == kSeedSize);
  
    __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalContextOffset));
    static const int kRandomSeedOffset =
        FixedArray::kHeaderSize + Context::RANDOM_SEED_INDEX * kPointerSize;
    __ ldr(r2, FieldMemOperand(r0, kRandomSeedOffset));
    // r2: FixedArray of the global context's random seeds
  
    // Load state[0].
    __ ldr(r1, FieldMemOperand(r2, ByteArray::kHeaderSize));
    __ cmp(r1, Operand(0));
    __ b(eq, deferred->entry());
    // Load state[1].
    __ ldr(r0, FieldMemOperand(r2, ByteArray::kHeaderSize + kSeedSize));
    // r1: state[0].
    // r0: state[1].
  
    // state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16)
    __ and_(r3, r1, Operand(0xFFFF));
    __ mov(r4, Operand(18273));
    __ mul(r3, r3, r4);
    __ add(r1, r3, Operand(r1, LSR, 16));
    // Save state[0].
    __ str(r1, FieldMemOperand(r2, ByteArray::kHeaderSize));
  
    // state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16)
    __ and_(r3, r0, Operand(0xFFFF));
    __ mov(r4, Operand(36969));
    __ mul(r3, r3, r4);
    __ add(r0, r3, Operand(r0, LSR, 16));
    // Save state[1].
    __ str(r0, FieldMemOperand(r2, ByteArray::kHeaderSize + kSeedSize));
  
    // Random bit pattern = (state[0] << 14) + (state[1] & 0x3FFFF)
    __ and_(r0, r0, Operand(0x3FFFF));
    __ add(r0, r0, Operand(r1, LSL, 14));
  
    __ bind(deferred->exit());
    // 0x41300000 is the top half of 1.0 x 2^20 as a double.
    // Create this constant using mov/orr to avoid PC relative load.
    __ mov(r1, Operand(0x41000000));
    __ orr(r1, r1, Operand(0x300000));
    // Move 0x41300000xxxxxxxx (x = random bits) to VFP.
    __ vmov(d7, r0, r1);
    // Move 0x4130000000000000 to VFP.
    __ mov(r0, Operand(0, RelocInfo::NONE));
    __ vmov(d8, r0, r1);
    // Subtract and store the result in the heap number.
    __ vsub(d7, d7, d8);
  }
  
  
  void LCodeGen::DoDeferredRandom(LRandom* instr) {
    __ PrepareCallCFunction(1, scratch0());
    __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1);
    // Return value is in r0.
  }
  
  
  void LCodeGen::DoMathLog(LUnaryMathOperation* instr) {
    ASSERT(ToDoubleRegister(instr->result()).is(d2));
    TranscendentalCacheStub stub(TranscendentalCache::LOG,
                                 TranscendentalCacheStub::UNTAGGED);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoMathTan(LUnaryMathOperation* instr) {
    ASSERT(ToDoubleRegister(instr->result()).is(d2));
    TranscendentalCacheStub stub(TranscendentalCache::TAN,
                                 TranscendentalCacheStub::UNTAGGED);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoMathCos(LUnaryMathOperation* instr) {
    ASSERT(ToDoubleRegister(instr->result()).is(d2));
    TranscendentalCacheStub stub(TranscendentalCache::COS,
                                 TranscendentalCacheStub::UNTAGGED);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoMathSin(LUnaryMathOperation* instr) {
    ASSERT(ToDoubleRegister(instr->result()).is(d2));
    TranscendentalCacheStub stub(TranscendentalCache::SIN,
                                 TranscendentalCacheStub::UNTAGGED);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoUnaryMathOperation(LUnaryMathOperation* instr) {
    switch (instr->op()) {
      case kMathAbs:
        DoMathAbs(instr);
        break;
      case kMathFloor:
        DoMathFloor(instr);
        break;
      case kMathRound:
        DoMathRound(instr);
        break;
      case kMathSqrt:
        DoMathSqrt(instr);
        break;
      case kMathPowHalf:
        DoMathPowHalf(instr);
        break;
      case kMathCos:
        DoMathCos(instr);
        break;
      case kMathSin:
        DoMathSin(instr);
        break;
      case kMathTan:
        DoMathTan(instr);
        break;
      case kMathLog:
        DoMathLog(instr);
        break;
      default:
        Abort("Unimplemented type of LUnaryMathOperation.");
        UNREACHABLE();
    }
  }
  
  
  void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
    ASSERT(ToRegister(instr->function()).is(r1));
    ASSERT(instr->HasPointerMap());
    ASSERT(instr->HasDeoptimizationEnvironment());
    LPointerMap* pointers = instr->pointer_map();
    RecordPosition(pointers->position());
    SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
    ParameterCount count(instr->arity());
    __ InvokeFunction(r1, count, CALL_FUNCTION, generator, CALL_AS_METHOD);
    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoCallKeyed(LCallKeyed* instr) {
    ASSERT(ToRegister(instr->result()).is(r0));
  
    int arity = instr->arity();
    Handle<Code> ic =
        isolate()->stub_cache()->ComputeKeyedCallInitialize(arity);
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoCallNamed(LCallNamed* instr) {
    ASSERT(ToRegister(instr->result()).is(r0));
  
    int arity = instr->arity();
    RelocInfo::Mode mode = RelocInfo::CODE_TARGET;
    Handle<Code> ic =
        isolate()->stub_cache()->ComputeCallInitialize(arity, mode);
    __ mov(r2, Operand(instr->name()));
    CallCode(ic, mode, instr);
    // Restore context register.
    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoCallFunction(LCallFunction* instr) {
    ASSERT(ToRegister(instr->function()).is(r1));
    ASSERT(ToRegister(instr->result()).is(r0));
  
    int arity = instr->arity();
    CallFunctionStub stub(arity, NO_CALL_FUNCTION_FLAGS);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoCallGlobal(LCallGlobal* instr) {
    ASSERT(ToRegister(instr->result()).is(r0));
  
    int arity = instr->arity();
    RelocInfo::Mode mode = RelocInfo::CODE_TARGET_CONTEXT;
    Handle<Code> ic =
        isolate()->stub_cache()->ComputeCallInitialize(arity, mode);
    __ mov(r2, Operand(instr->name()));
    CallCode(ic, mode, instr);
    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoCallKnownGlobal(LCallKnownGlobal* instr) {
    ASSERT(ToRegister(instr->result()).is(r0));
    CallKnownFunction(instr->target(), instr->arity(), instr, CALL_AS_FUNCTION);
  }
  
  
  void LCodeGen::DoCallNew(LCallNew* instr) {
    ASSERT(ToRegister(instr->InputAt(0)).is(r1));
    ASSERT(ToRegister(instr->result()).is(r0));
  
    CallConstructStub stub(NO_CALL_FUNCTION_FLAGS);
    __ mov(r0, Operand(instr->arity()));
    CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
  }
  
  
  void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
    CallRuntime(instr->function(), instr->arity(), instr);
  }
  
  
  void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
    Register object = ToRegister(instr->object());
    Register value = ToRegister(instr->value());
    Register scratch = scratch0();
    int offset = instr->offset();
  
    ASSERT(!object.is(value));
  
    if (!instr->transition().is_null()) {
      __ mov(scratch, Operand(instr->transition()));
      __ str(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
    }
  
    // Do the store.
    HType type = instr->hydrogen()->value()->type();
    SmiCheck check_needed =
        type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
    if (instr->is_in_object()) {
      __ str(value, FieldMemOperand(object, offset));
      if (instr->hydrogen()->NeedsWriteBarrier()) {
        // Update the write barrier for the object for in-object properties.
        __ RecordWriteField(object,
                            offset,
                            value,
                            scratch,
                            kLRHasBeenSaved,
                            kSaveFPRegs,
                            EMIT_REMEMBERED_SET,
                            check_needed);
      }
    } else {
      __ ldr(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
      __ str(value, FieldMemOperand(scratch, offset));
      if (instr->hydrogen()->NeedsWriteBarrier()) {
        // Update the write barrier for the properties array.
        // object is used as a scratch register.
        __ RecordWriteField(scratch,
                            offset,
                            value,
                            object,
                            kLRHasBeenSaved,
                            kSaveFPRegs,
                            EMIT_REMEMBERED_SET,
                            check_needed);
      }
    }
  }
  
  
  void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
    ASSERT(ToRegister(instr->object()).is(r1));
    ASSERT(ToRegister(instr->value()).is(r0));
  
    // Name is always in r2.
    __ mov(r2, Operand(instr->name()));
    Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
        ? isolate()->builtins()->StoreIC_Initialize_Strict()
        : isolate()->builtins()->StoreIC_Initialize();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
    __ cmp(ToRegister(instr->index()), ToRegister(instr->length()));
    DeoptimizeIf(hs, instr->environment());
  }
  
  
  void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
    Register value = ToRegister(instr->value());
    Register elements = ToRegister(instr->object());
    Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
    Register scratch = scratch0();
  
    // Do the store.
    if (instr->key()->IsConstantOperand()) {
      ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
      LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
      int offset =
          ToInteger32(const_operand) * kPointerSize + FixedArray::kHeaderSize;
      __ str(value, FieldMemOperand(elements, offset));
    } else {
      __ add(scratch, elements, Operand(key, LSL, kPointerSizeLog2));
      __ str(value, FieldMemOperand(scratch, FixedArray::kHeaderSize));
    }
  
    if (instr->hydrogen()->NeedsWriteBarrier()) {
      HType type = instr->hydrogen()->value()->type();
      SmiCheck check_needed =
          type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
      // Compute address of modified element and store it into key register.
      __ add(key, scratch, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
      __ RecordWrite(elements,
                     key,
                     value,
                     kLRHasBeenSaved,
                     kSaveFPRegs,
                     EMIT_REMEMBERED_SET,
                     check_needed);
    }
  }
  
  
  void LCodeGen::DoStoreKeyedFastDoubleElement(
      LStoreKeyedFastDoubleElement* instr) {
    DwVfpRegister value = ToDoubleRegister(instr->value());
    Register elements = ToRegister(instr->elements());
    Register key = no_reg;
    Register scratch = scratch0();
    bool key_is_constant = instr->key()->IsConstantOperand();
    int constant_key = 0;
    Label not_nan;
  
    // Calculate the effective address of the slot in the array to store the
    // double value.
    if (key_is_constant) {
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xF0000000) {
        Abort("array index constant value too big.");
      }
    } else {
      key = ToRegister(instr->key());
    }
    int shift_size = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
    Operand operand = key_is_constant
        ? Operand(constant_key * (1 << shift_size) +
                  FixedDoubleArray::kHeaderSize - kHeapObjectTag)
        : Operand(key, LSL, shift_size);
    __ add(scratch, elements, operand);
    if (!key_is_constant) {
      __ add(scratch, scratch,
             Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
    }
  
    // Check for NaN. All NaNs must be canonicalized.
    __ VFPCompareAndSetFlags(value, value);
  
    // Only load canonical NaN if the comparison above set the overflow.
    __ Vmov(value, FixedDoubleArray::canonical_not_the_hole_nan_as_double(), vs);
  
    __ bind(&not_nan);
    __ vstr(value, scratch, 0);
  }
  
  
  void LCodeGen::DoStoreKeyedSpecializedArrayElement(
      LStoreKeyedSpecializedArrayElement* instr) {
  
    Register external_pointer = ToRegister(instr->external_pointer());
    Register key = no_reg;
    ElementsKind elements_kind = instr->elements_kind();
    bool key_is_constant = instr->key()->IsConstantOperand();
    int constant_key = 0;
    if (key_is_constant) {
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xF0000000) {
        Abort("array index constant value too big.");
      }
    } else {
      key = ToRegister(instr->key());
    }
    int shift_size = ElementsKindToShiftSize(elements_kind);
  
    if (elements_kind == EXTERNAL_FLOAT_ELEMENTS ||
        elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
      CpuFeatures::Scope scope(VFP3);
      DwVfpRegister value(ToDoubleRegister(instr->value()));
      Operand operand(key_is_constant ? Operand(constant_key * (1 << shift_size))
                                      : Operand(key, LSL, shift_size));
      __ add(scratch0(), external_pointer, operand);
      if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
        __ vcvt_f32_f64(double_scratch0().low(), value);
        __ vstr(double_scratch0().low(), scratch0(), 0);
      } else {  // i.e. elements_kind == EXTERNAL_DOUBLE_ELEMENTS
        __ vstr(value, scratch0(), 0);
      }
    } else {
      Register value(ToRegister(instr->value()));
      MemOperand mem_operand(key_is_constant
          ? MemOperand(external_pointer, constant_key * (1 << shift_size))
          : MemOperand(external_pointer, key, LSL, shift_size));
      switch (elements_kind) {
        case EXTERNAL_PIXEL_ELEMENTS:
        case EXTERNAL_BYTE_ELEMENTS:
        case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
          __ strb(value, mem_operand);
          break;
        case EXTERNAL_SHORT_ELEMENTS:
        case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
          __ strh(value, mem_operand);
          break;
        case EXTERNAL_INT_ELEMENTS:
        case EXTERNAL_UNSIGNED_INT_ELEMENTS:
          __ str(value, mem_operand);
          break;
        case EXTERNAL_FLOAT_ELEMENTS:
        case EXTERNAL_DOUBLE_ELEMENTS:
        case FAST_DOUBLE_ELEMENTS:
        case FAST_ELEMENTS:
        case FAST_SMI_ONLY_ELEMENTS:
        case DICTIONARY_ELEMENTS:
        case NON_STRICT_ARGUMENTS_ELEMENTS:
          UNREACHABLE();
          break;
      }
    }
  }
  
  
  void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
    ASSERT(ToRegister(instr->object()).is(r2));
    ASSERT(ToRegister(instr->key()).is(r1));
    ASSERT(ToRegister(instr->value()).is(r0));
  
    Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
        ? isolate()->builtins()->KeyedStoreIC_Initialize_Strict()
        : isolate()->builtins()->KeyedStoreIC_Initialize();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
    Register object_reg = ToRegister(instr->object());
    Register new_map_reg = ToRegister(instr->new_map_reg());
    Register scratch = scratch0();
  
    Handle<Map> from_map = instr->original_map();
    Handle<Map> to_map = instr->transitioned_map();
    ElementsKind from_kind = from_map->elements_kind();
    ElementsKind to_kind = to_map->elements_kind();
  
    Label not_applicable;
    __ ldr(scratch, FieldMemOperand(object_reg, HeapObject::kMapOffset));
    __ cmp(scratch, Operand(from_map));
    __ b(ne, &not_applicable);
    __ mov(new_map_reg, Operand(to_map));
    if (from_kind == FAST_SMI_ONLY_ELEMENTS && to_kind == FAST_ELEMENTS) {
      __ str(new_map_reg, FieldMemOperand(object_reg, HeapObject::kMapOffset));
      // Write barrier.
      __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
                          scratch, kLRHasBeenSaved, kDontSaveFPRegs);
    } else if (from_kind == FAST_SMI_ONLY_ELEMENTS &&
        to_kind == FAST_DOUBLE_ELEMENTS) {
      Register fixed_object_reg = ToRegister(instr->temp_reg());
      ASSERT(fixed_object_reg.is(r2));
      ASSERT(new_map_reg.is(r3));
      __ mov(fixed_object_reg, object_reg);
      CallCode(isolate()->builtins()->TransitionElementsSmiToDouble(),
               RelocInfo::CODE_TARGET, instr);
    } else if (from_kind == FAST_DOUBLE_ELEMENTS && to_kind == FAST_ELEMENTS) {
      Register fixed_object_reg = ToRegister(instr->temp_reg());
      ASSERT(fixed_object_reg.is(r2));
      ASSERT(new_map_reg.is(r3));
      __ mov(fixed_object_reg, object_reg);
      CallCode(isolate()->builtins()->TransitionElementsDoubleToObject(),
               RelocInfo::CODE_TARGET, instr);
    } else {
      UNREACHABLE();
    }
    __ bind(&not_applicable);
  }
  
  
  void LCodeGen::DoStringAdd(LStringAdd* instr) {
    __ push(ToRegister(instr->left()));
    __ push(ToRegister(instr->right()));
    StringAddStub stub(NO_STRING_CHECK_IN_STUB);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoStringCharCodeAt(LStringCharCodeAt* instr) {
    class DeferredStringCharCodeAt: public LDeferredCode {
     public:
      DeferredStringCharCodeAt(LCodeGen* codegen, LStringCharCodeAt* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() { codegen()->DoDeferredStringCharCodeAt(instr_); }
      virtual LInstruction* instr() { return instr_; }
     private:
      LStringCharCodeAt* instr_;
    };
  
    DeferredStringCharCodeAt* deferred =
        new DeferredStringCharCodeAt(this, instr);
  
    StringCharLoadGenerator::Generate(masm(),
                                      ToRegister(instr->string()),
                                      ToRegister(instr->index()),
                                      ToRegister(instr->result()),
                                      deferred->entry());
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredStringCharCodeAt(LStringCharCodeAt* instr) {
    Register string = ToRegister(instr->string());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
  
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    __ mov(result, Operand(0));
  
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
    __ push(string);
    // Push the index as a smi. This is safe because of the checks in
    // DoStringCharCodeAt above.
    if (instr->index()->IsConstantOperand()) {
      int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
      __ mov(scratch, Operand(Smi::FromInt(const_index)));
      __ push(scratch);
    } else {
      Register index = ToRegister(instr->index());
      __ SmiTag(index);
      __ push(index);
    }
    CallRuntimeFromDeferred(Runtime::kStringCharCodeAt, 2, instr);
    if (FLAG_debug_code) {
      __ AbortIfNotSmi(r0);
    }
    __ SmiUntag(r0);
    __ StoreToSafepointRegisterSlot(r0, 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 DeferredStringCharFromCode(this, instr);
  
    ASSERT(instr->hydrogen()->value()->representation().IsInteger32());
    Register char_code = ToRegister(instr->char_code());
    Register result = ToRegister(instr->result());
    ASSERT(!char_code.is(result));
  
    __ cmp(char_code, Operand(String::kMaxAsciiCharCode));
    __ b(hi, deferred->entry());
    __ LoadRoot(result, Heap::kSingleCharacterStringCacheRootIndex);
    __ add(result, result, Operand(char_code, LSL, kPointerSizeLog2));
    __ ldr(result, FieldMemOperand(result, FixedArray::kHeaderSize));
    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
    __ cmp(result, ip);
    __ 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, Operand(0));
  
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
    __ SmiTag(char_code);
    __ push(char_code);
    CallRuntimeFromDeferred(Runtime::kCharFromCode, 1, instr);
    __ StoreToSafepointRegisterSlot(r0, result);
  }
  
  
  void LCodeGen::DoStringLength(LStringLength* instr) {
    Register string = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    __ ldr(result, FieldMemOperand(string, String::kLengthOffset));
  }
  
  
  void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
    LOperand* input = instr->InputAt(0);
    ASSERT(input->IsRegister() || input->IsStackSlot());
    LOperand* output = instr->result();
    ASSERT(output->IsDoubleRegister());
    SwVfpRegister single_scratch = double_scratch0().low();
    if (input->IsStackSlot()) {
      Register scratch = scratch0();
      __ ldr(scratch, ToMemOperand(input));
      __ vmov(single_scratch, scratch);
    } else {
      __ vmov(single_scratch, ToRegister(input));
    }
    __ vcvt_f64_s32(ToDoubleRegister(output), single_scratch);
  }
  
  
  void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
    class DeferredNumberTagI: public LDeferredCode {
     public:
      DeferredNumberTagI(LCodeGen* codegen, LNumberTagI* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() { codegen()->DoDeferredNumberTagI(instr_); }
      virtual LInstruction* instr() { return instr_; }
     private:
      LNumberTagI* instr_;
    };
  
    Register src = ToRegister(instr->InputAt(0));
    Register dst = ToRegister(instr->result());
  
    DeferredNumberTagI* deferred = new DeferredNumberTagI(this, instr);
    __ SmiTag(dst, src, SetCC);
    __ b(vs, deferred->entry());
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredNumberTagI(LNumberTagI* instr) {
    Label slow;
    Register src = ToRegister(instr->InputAt(0));
    Register dst = ToRegister(instr->result());
    DoubleRegister dbl_scratch = double_scratch0();
    SwVfpRegister flt_scratch = dbl_scratch.low();
  
    // Preserve the value of all registers.
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
  
    // There was overflow, so bits 30 and 31 of the original integer
    // disagree. Try to allocate a heap number in new space and store
    // the value in there. If that fails, call the runtime system.
    Label done;
    if (dst.is(src)) {
      __ SmiUntag(src, dst);
      __ eor(src, src, Operand(0x80000000));
    }
    __ vmov(flt_scratch, src);
    __ vcvt_f64_s32(dbl_scratch, flt_scratch);
    if (FLAG_inline_new) {
      __ LoadRoot(r6, Heap::kHeapNumberMapRootIndex);
      __ AllocateHeapNumber(r5, r3, r4, r6, &slow);
      __ Move(dst, r5);
      __ b(&done);
    }
  
    // Slow case: Call the runtime system to do the number allocation.
    __ bind(&slow);
  
    // TODO(3095996): Put a valid pointer value in the stack slot where the result
    // register is stored, as this register is in the pointer map, but contains an
    // integer value.
    __ mov(ip, Operand(0));
    __ StoreToSafepointRegisterSlot(ip, dst);
    CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
    __ Move(dst, r0);
  
    // Done. Put the value in dbl_scratch into the value of the allocated heap
    // number.
    __ bind(&done);
    __ sub(ip, dst, Operand(kHeapObjectTag));
    __ vstr(dbl_scratch, ip, HeapNumber::kValueOffset);
    __ StoreToSafepointRegisterSlot(dst, dst);
  }
  
  
  void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
    class DeferredNumberTagD: public LDeferredCode {
     public:
      DeferredNumberTagD(LCodeGen* codegen, LNumberTagD* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() { codegen()->DoDeferredNumberTagD(instr_); }
      virtual LInstruction* instr() { return instr_; }
     private:
      LNumberTagD* instr_;
    };
  
    DoubleRegister input_reg = ToDoubleRegister(instr->InputAt(0));
    Register scratch = scratch0();
    Register reg = ToRegister(instr->result());
    Register temp1 = ToRegister(instr->TempAt(0));
    Register temp2 = ToRegister(instr->TempAt(1));
  
    DeferredNumberTagD* deferred = new DeferredNumberTagD(this, instr);
    if (FLAG_inline_new) {
      __ LoadRoot(scratch, Heap::kHeapNumberMapRootIndex);
      __ AllocateHeapNumber(reg, temp1, temp2, scratch, deferred->entry());
    } else {
      __ jmp(deferred->entry());
    }
    __ bind(deferred->exit());
    __ sub(ip, reg, Operand(kHeapObjectTag));
    __ vstr(input_reg, ip, HeapNumber::kValueOffset);
  }
  
  
  void LCodeGen::DoDeferredNumberTagD(LNumberTagD* instr) {
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    Register reg = ToRegister(instr->result());
    __ mov(reg, Operand(0));
  
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
    CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
    __ StoreToSafepointRegisterSlot(r0, reg);
  }
  
  
  void LCodeGen::DoSmiTag(LSmiTag* instr) {
    ASSERT(!instr->hydrogen_value()->CheckFlag(HValue::kCanOverflow));
    __ SmiTag(ToRegister(instr->result()), ToRegister(instr->InputAt(0)));
  }
  
  
  void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register result = ToRegister(instr->result());
    if (instr->needs_check()) {
      STATIC_ASSERT(kHeapObjectTag == 1);
      // If the input is a HeapObject, SmiUntag will set the carry flag.
      __ SmiUntag(result, input, SetCC);
      DeoptimizeIf(cs, instr->environment());
    } else {
      __ SmiUntag(result, input);
    }
  }
  
  
  void LCodeGen::EmitNumberUntagD(Register input_reg,
                                  DoubleRegister result_reg,
                                  bool deoptimize_on_undefined,
                                  bool deoptimize_on_minus_zero,
                                  LEnvironment* env) {
    Register scratch = scratch0();
    SwVfpRegister flt_scratch = double_scratch0().low();
    ASSERT(!result_reg.is(double_scratch0()));
  
    Label load_smi, heap_number, done;
  
    // Smi check.
    __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);
  
    // Heap number map check.
    __ ldr(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
    __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
    __ cmp(scratch, Operand(ip));
    if (deoptimize_on_undefined) {
      DeoptimizeIf(ne, env);
    } else {
      Label heap_number;
      __ b(eq, &heap_number);
  
      __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
      __ cmp(input_reg, Operand(ip));
      DeoptimizeIf(ne, env);
  
      // Convert undefined to NaN.
      __ LoadRoot(ip, Heap::kNanValueRootIndex);
      __ sub(ip, ip, Operand(kHeapObjectTag));
      __ vldr(result_reg, ip, HeapNumber::kValueOffset);
      __ jmp(&done);
  
      __ bind(&heap_number);
    }
    // Heap number to double register conversion.
    __ sub(ip, input_reg, Operand(kHeapObjectTag));
    __ vldr(result_reg, ip, HeapNumber::kValueOffset);
    if (deoptimize_on_minus_zero) {
      __ vmov(ip, result_reg.low());
      __ cmp(ip, Operand(0));
      __ b(ne, &done);
      __ vmov(ip, result_reg.high());
      __ cmp(ip, Operand(HeapNumber::kSignMask));
      DeoptimizeIf(eq, env);
    }
    __ jmp(&done);
  
    // Smi to double register conversion
    __ bind(&load_smi);
    // scratch: untagged value of input_reg
    __ vmov(flt_scratch, scratch);
    __ vcvt_f64_s32(result_reg, flt_scratch);
    __ bind(&done);
  }
  
  
  void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
    Register input_reg = ToRegister(instr->InputAt(0));
    Register scratch1 = scratch0();
    Register scratch2 = ToRegister(instr->TempAt(0));
    DwVfpRegister double_scratch = double_scratch0();
    SwVfpRegister single_scratch = double_scratch.low();
  
    ASSERT(!scratch1.is(input_reg) && !scratch1.is(scratch2));
    ASSERT(!scratch2.is(input_reg) && !scratch2.is(scratch1));
  
    Label done;
  
    // The input was optimistically untagged; revert it.
    // The carry flag is set when we reach this deferred code as we just executed
    // SmiUntag(heap_object, SetCC)
    STATIC_ASSERT(kHeapObjectTag == 1);
    __ adc(input_reg, input_reg, Operand(input_reg));
  
    // Heap number map check.
    __ ldr(scratch1, FieldMemOperand(input_reg, HeapObject::kMapOffset));
    __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
    __ cmp(scratch1, Operand(ip));
  
    if (instr->truncating()) {
      Register scratch3 = ToRegister(instr->TempAt(1));
      DwVfpRegister double_scratch2 = ToDoubleRegister(instr->TempAt(2));
      ASSERT(!scratch3.is(input_reg) &&
             !scratch3.is(scratch1) &&
             !scratch3.is(scratch2));
      // Performs a truncating conversion of a floating point number as used by
      // the JS bitwise operations.
      Label heap_number;
      __ b(eq, &heap_number);
      // Check for undefined. Undefined is converted to zero for truncating
      // conversions.
      __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
      __ cmp(input_reg, Operand(ip));
      DeoptimizeIf(ne, instr->environment());
      __ mov(input_reg, Operand(0));
      __ b(&done);
  
      __ bind(&heap_number);
      __ sub(scratch1, input_reg, Operand(kHeapObjectTag));
      __ vldr(double_scratch2, scratch1, HeapNumber::kValueOffset);
  
      __ EmitECMATruncate(input_reg,
                          double_scratch2,
                          single_scratch,
                          scratch1,
                          scratch2,
                          scratch3);
  
    } else {
      CpuFeatures::Scope scope(VFP3);
      // Deoptimize if we don't have a heap number.
      DeoptimizeIf(ne, instr->environment());
  
      __ sub(ip, input_reg, Operand(kHeapObjectTag));
      __ vldr(double_scratch, ip, HeapNumber::kValueOffset);
      __ EmitVFPTruncate(kRoundToZero,
                         single_scratch,
                         double_scratch,
                         scratch1,
                         scratch2,
                         kCheckForInexactConversion);
      DeoptimizeIf(ne, instr->environment());
      // Load the result.
      __ vmov(input_reg, single_scratch);
  
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        __ cmp(input_reg, Operand(0));
        __ b(ne, &done);
        __ vmov(scratch1, double_scratch.high());
        __ tst(scratch1, Operand(HeapNumber::kSignMask));
        DeoptimizeIf(ne, instr->environment());
      }
    }
    __ bind(&done);
  }
  
  
  void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
    class DeferredTaggedToI: public LDeferredCode {
     public:
      DeferredTaggedToI(LCodeGen* codegen, LTaggedToI* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() { codegen()->DoDeferredTaggedToI(instr_); }
      virtual LInstruction* instr() { return instr_; }
     private:
      LTaggedToI* instr_;
    };
  
    LOperand* input = instr->InputAt(0);
    ASSERT(input->IsRegister());
    ASSERT(input->Equals(instr->result()));
  
    Register input_reg = ToRegister(input);
  
    DeferredTaggedToI* deferred = new DeferredTaggedToI(this, instr);
  
    // Optimistically untag the input.
    // If the input is a HeapObject, SmiUntag will set the carry flag.
    __ SmiUntag(input_reg, SetCC);
    // Branch to deferred code if the input was tagged.
    // The deferred code will take care of restoring the tag.
    __ b(cs, deferred->entry());
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
    LOperand* input = instr->InputAt(0);
    ASSERT(input->IsRegister());
    LOperand* result = instr->result();
    ASSERT(result->IsDoubleRegister());
  
    Register input_reg = ToRegister(input);
    DoubleRegister result_reg = ToDoubleRegister(result);
  
    EmitNumberUntagD(input_reg, result_reg,
                     instr->hydrogen()->deoptimize_on_undefined(),
                     instr->hydrogen()->deoptimize_on_minus_zero(),
                     instr->environment());
  }
  
  
  void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
    Register result_reg = ToRegister(instr->result());
    Register scratch1 = scratch0();
    Register scratch2 = ToRegister(instr->TempAt(0));
    DwVfpRegister double_input = ToDoubleRegister(instr->InputAt(0));
    SwVfpRegister single_scratch = double_scratch0().low();
  
    Label done;
  
    if (instr->truncating()) {
      Register scratch3 = ToRegister(instr->TempAt(1));
      __ EmitECMATruncate(result_reg,
                          double_input,
                          single_scratch,
                          scratch1,
                          scratch2,
                          scratch3);
    } else {
      VFPRoundingMode rounding_mode = kRoundToMinusInf;
      __ EmitVFPTruncate(rounding_mode,
                         single_scratch,
                         double_input,
                         scratch1,
                         scratch2,
                         kCheckForInexactConversion);
      // Deoptimize if we had a vfp invalid exception,
      // including inexact operation.
      DeoptimizeIf(ne, instr->environment());
      // Retrieve the result.
      __ vmov(result_reg, single_scratch);
    }
      __ bind(&done);
  }
  
  
  void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
    LOperand* input = instr->InputAt(0);
    __ tst(ToRegister(input), Operand(kSmiTagMask));
    DeoptimizeIf(ne, instr->environment());
  }
  
  
  void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
    LOperand* input = instr->InputAt(0);
    __ tst(ToRegister(input), Operand(kSmiTagMask));
    DeoptimizeIf(eq, instr->environment());
  }
  
  
  void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
    Register input = ToRegister(instr->InputAt(0));
    Register scratch = scratch0();
  
    __ ldr(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
    __ ldrb(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
  
    if (instr->hydrogen()->is_interval_check()) {
      InstanceType first;
      InstanceType last;
      instr->hydrogen()->GetCheckInterval(&first, &last);
  
      __ cmp(scratch, Operand(first));
  
      // If there is only one type in the interval check for equality.
      if (first == last) {
        DeoptimizeIf(ne, instr->environment());
      } else {
        DeoptimizeIf(lo, instr->environment());
        // Omit check for the last type.
        if (last != LAST_TYPE) {
          __ cmp(scratch, Operand(last));
          DeoptimizeIf(hi, instr->environment());
        }
      }
    } else {
      uint8_t mask;
      uint8_t tag;
      instr->hydrogen()->GetCheckMaskAndTag(&mask, &tag);
  
      if (IsPowerOf2(mask)) {
        ASSERT(tag == 0 || IsPowerOf2(tag));
        __ tst(scratch, Operand(mask));
        DeoptimizeIf(tag == 0 ? ne : eq, instr->environment());
      } else {
        __ and_(scratch, scratch, Operand(mask));
        __ cmp(scratch, Operand(tag));
        DeoptimizeIf(ne, instr->environment());
      }
    }
  }
  
  
  void LCodeGen::DoCheckFunction(LCheckFunction* instr) {
    Register reg = ToRegister(instr->value());
    Handle<JSFunction> target = instr->hydrogen()->target();
    if (isolate()->heap()->InNewSpace(*target)) {
      Register reg = ToRegister(instr->value());
      Handle<JSGlobalPropertyCell> cell =
          isolate()->factory()->NewJSGlobalPropertyCell(target);
      __ mov(ip, Operand(Handle<Object>(cell)));
      __ ldr(ip, FieldMemOperand(ip, JSGlobalPropertyCell::kValueOffset));
      __ cmp(reg, ip);
    } else {
      __ cmp(reg, Operand(target));
    }
    DeoptimizeIf(ne, instr->environment());
  }
  
  
  void LCodeGen::DoCheckMapCommon(Register reg,
                                  Register scratch,
                                  Handle<Map> map,
                                  CompareMapMode mode,
                                  LEnvironment* env) {
    Label success;
    __ CompareMap(reg, scratch, map, &success, mode);
    DeoptimizeIf(ne, env);
    __ bind(&success);
  }
  
  
  void LCodeGen::DoCheckMap(LCheckMap* instr) {
    Register scratch = scratch0();
    LOperand* input = instr->InputAt(0);
    ASSERT(input->IsRegister());
    Register reg = ToRegister(input);
    Handle<Map> map = instr->hydrogen()->map();
    DoCheckMapCommon(reg, scratch, map, instr->hydrogen()->mode(),
                     instr->environment());
  }
  
  
  void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
    DoubleRegister value_reg = ToDoubleRegister(instr->unclamped());
    Register result_reg = ToRegister(instr->result());
    DoubleRegister temp_reg = ToDoubleRegister(instr->TempAt(0));
    __ ClampDoubleToUint8(result_reg, value_reg, temp_reg);
  }
  
  
  void LCodeGen::DoClampIToUint8(LClampIToUint8* instr) {
    Register unclamped_reg = ToRegister(instr->unclamped());
    Register result_reg = ToRegister(instr->result());
    __ ClampUint8(result_reg, unclamped_reg);
  }
  
  
  void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
    Register scratch = scratch0();
    Register input_reg = ToRegister(instr->unclamped());
    Register result_reg = ToRegister(instr->result());
    DoubleRegister temp_reg = ToDoubleRegister(instr->TempAt(0));
    Label is_smi, done, heap_number;
  
    // Both smi and heap number cases are handled.
    __ UntagAndJumpIfSmi(result_reg, input_reg, &is_smi);
  
    // Check for heap number
    __ ldr(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
    __ cmp(scratch, Operand(factory()->heap_number_map()));
    __ b(eq, &heap_number);
  
    // Check for undefined. Undefined is converted to zero for clamping
    // conversions.
    __ cmp(input_reg, Operand(factory()->undefined_value()));
    DeoptimizeIf(ne, instr->environment());
    __ mov(result_reg, Operand(0));
    __ jmp(&done);
  
    // Heap number
    __ bind(&heap_number);
    __ vldr(double_scratch0(), FieldMemOperand(input_reg,
                                               HeapNumber::kValueOffset));
    __ ClampDoubleToUint8(result_reg, double_scratch0(), temp_reg);
    __ jmp(&done);
  
    // smi
    __ bind(&is_smi);
    __ ClampUint8(result_reg, result_reg);
  
    __ bind(&done);
  }
  
  
  void LCodeGen::DoCheckPrototypeMaps(LCheckPrototypeMaps* instr) {
    Register temp1 = ToRegister(instr->TempAt(0));
    Register temp2 = ToRegister(instr->TempAt(1));
  
    Handle<JSObject> holder = instr->holder();
    Handle<JSObject> current_prototype = instr->prototype();
  
    // Load prototype object.
    __ LoadHeapObject(temp1, current_prototype);
  
    // Check prototype maps up to the holder.
    while (!current_prototype.is_identical_to(holder)) {
      DoCheckMapCommon(temp1, temp2,
                       Handle<Map>(current_prototype->map()),
                       ALLOW_ELEMENT_TRANSITION_MAPS, instr->environment());
      current_prototype =
          Handle<JSObject>(JSObject::cast(current_prototype->GetPrototype()));
      // Load next prototype object.
      __ LoadHeapObject(temp1, current_prototype);
    }
  
    // Check the holder map.
    DoCheckMapCommon(temp1, temp2,
                     Handle<Map>(current_prototype->map()),
                     ALLOW_ELEMENT_TRANSITION_MAPS, instr->environment());
    DeoptimizeIf(ne, instr->environment());
  }
  
  
  void LCodeGen::DoAllocateObject(LAllocateObject* instr) {
    class DeferredAllocateObject: public LDeferredCode {
     public:
      DeferredAllocateObject(LCodeGen* codegen, LAllocateObject* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() { codegen()->DoDeferredAllocateObject(instr_); }
      virtual LInstruction* instr() { return instr_; }
     private:
      LAllocateObject* instr_;
    };
  
    DeferredAllocateObject* deferred = new DeferredAllocateObject(this, instr);
  
    Register result = ToRegister(instr->result());
    Register scratch = ToRegister(instr->TempAt(0));
    Register scratch2 = ToRegister(instr->TempAt(1));
    Handle<JSFunction> constructor = instr->hydrogen()->constructor();
    Handle<Map> initial_map(constructor->initial_map());
    int instance_size = initial_map->instance_size();
    ASSERT(initial_map->pre_allocated_property_fields() +
           initial_map->unused_property_fields() -
           initial_map->inobject_properties() == 0);
  
    // Allocate memory for the object.  The initial map might change when
    // the constructor's prototype changes, but instance size and property
    // counts remain unchanged (if slack tracking finished).
    ASSERT(!constructor->shared()->IsInobjectSlackTrackingInProgress());
    __ AllocateInNewSpace(instance_size,
                          result,
                          scratch,
                          scratch2,
                          deferred->entry(),
                          TAG_OBJECT);
  
    // Load the initial map.
    Register map = scratch;
    __ LoadHeapObject(map, constructor);
    __ ldr(map, FieldMemOperand(map, JSFunction::kPrototypeOrInitialMapOffset));
  
    // Initialize map and fields of the newly allocated object.
    ASSERT(initial_map->instance_type() == JS_OBJECT_TYPE);
    __ str(map, FieldMemOperand(result, JSObject::kMapOffset));
    __ LoadRoot(scratch, Heap::kEmptyFixedArrayRootIndex);
    __ str(scratch, FieldMemOperand(result, JSObject::kElementsOffset));
    __ str(scratch, FieldMemOperand(result, JSObject::kPropertiesOffset));
    if (initial_map->inobject_properties() != 0) {
      __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
      for (int i = 0; i < initial_map->inobject_properties(); i++) {
        int property_offset = JSObject::kHeaderSize + i * kPointerSize;
        __ str(scratch, FieldMemOperand(result, property_offset));
      }
    }
  
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredAllocateObject(LAllocateObject* instr) {
    Register result = ToRegister(instr->result());
    Handle<JSFunction> constructor = instr->hydrogen()->constructor();
  
    // 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, Operand(0));
  
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
    __ LoadHeapObject(r0, constructor);
    __ push(r0);
    CallRuntimeFromDeferred(Runtime::kNewObject, 1, instr);
    __ StoreToSafepointRegisterSlot(r0, result);
  }
  
  
  void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
    Heap* heap = isolate()->heap();
    ElementsKind boilerplate_elements_kind =
        instr->hydrogen()->boilerplate_elements_kind();
  
    // Deopt if the array literal boilerplate ElementsKind is of a type different
    // than the expected one. The check isn't necessary if the boilerplate has
    // already been converted to FAST_ELEMENTS.
    if (boilerplate_elements_kind != FAST_ELEMENTS) {
      __ LoadHeapObject(r1, instr->hydrogen()->boilerplate_object());
      // Load map into r2.
      __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
      // Load the map's "bit field 2".
      __ ldrb(r2, FieldMemOperand(r2, Map::kBitField2Offset));
      // Retrieve elements_kind from bit field 2.
      __ ubfx(r2, r2, Map::kElementsKindShift, Map::kElementsKindBitCount);
      __ cmp(r2, Operand(boilerplate_elements_kind));
      DeoptimizeIf(ne, instr->environment());
    }
  
    __ ldr(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
    __ ldr(r3, FieldMemOperand(r3, JSFunction::kLiteralsOffset));
    __ mov(r2, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
    // Boilerplate already exists, constant elements are never accessed.
    // Pass an empty fixed array.
    __ mov(r1, Operand(Handle<FixedArray>(heap->empty_fixed_array())));
    __ Push(r3, r2, r1);
  
    // Pick the right runtime function or stub to call.
    int length = instr->hydrogen()->length();
    if (instr->hydrogen()->IsCopyOnWrite()) {
      ASSERT(instr->hydrogen()->depth() == 1);
      FastCloneShallowArrayStub::Mode mode =
          FastCloneShallowArrayStub::COPY_ON_WRITE_ELEMENTS;
      FastCloneShallowArrayStub stub(mode, length);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    } else if (instr->hydrogen()->depth() > 1) {
      CallRuntime(Runtime::kCreateArrayLiteral, 3, instr);
    } else if (length > FastCloneShallowArrayStub::kMaximumClonedLength) {
      CallRuntime(Runtime::kCreateArrayLiteralShallow, 3, instr);
    } else {
      FastCloneShallowArrayStub::Mode mode =
          boilerplate_elements_kind == FAST_DOUBLE_ELEMENTS
              ? FastCloneShallowArrayStub::CLONE_DOUBLE_ELEMENTS
              : FastCloneShallowArrayStub::CLONE_ELEMENTS;
      FastCloneShallowArrayStub stub(mode, length);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    }
  }
  
  
  void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
                              Register result,
                              Register source,
                              int* offset) {
    ASSERT(!source.is(r2));
    ASSERT(!result.is(r2));
  
    // Only elements backing stores for non-COW arrays need to be copied.
    Handle<FixedArrayBase> elements(object->elements());
    bool has_elements = elements->length() > 0 &&
        elements->map() != isolate()->heap()->fixed_cow_array_map();
  
    // Increase the offset so that subsequent objects end up right after
    // this object and its backing store.
    int object_offset = *offset;
    int object_size = object->map()->instance_size();
    int elements_offset = *offset + object_size;
    int elements_size = has_elements ? elements->Size() : 0;
    *offset += object_size + elements_size;
  
    // Copy object header.
    ASSERT(object->properties()->length() == 0);
    int inobject_properties = object->map()->inobject_properties();
    int header_size = object_size - inobject_properties * kPointerSize;
    for (int i = 0; i < header_size; i += kPointerSize) {
      if (has_elements && i == JSObject::kElementsOffset) {
        __ add(r2, result, Operand(elements_offset));
      } else {
        __ ldr(r2, FieldMemOperand(source, i));
      }
      __ str(r2, FieldMemOperand(result, object_offset + i));
    }
  
    // Copy in-object properties.
    for (int i = 0; i < inobject_properties; i++) {
      int total_offset = object_offset + object->GetInObjectPropertyOffset(i);
      Handle<Object> value = Handle<Object>(object->InObjectPropertyAt(i));
      if (value->IsJSObject()) {
        Handle<JSObject> value_object = Handle<JSObject>::cast(value);
        __ add(r2, result, Operand(*offset));
        __ str(r2, FieldMemOperand(result, total_offset));
        __ LoadHeapObject(source, value_object);
        EmitDeepCopy(value_object, result, source, offset);
      } else if (value->IsHeapObject()) {
        __ LoadHeapObject(r2, Handle<HeapObject>::cast(value));
        __ str(r2, FieldMemOperand(result, total_offset));
      } else {
        __ mov(r2, Operand(value));
        __ str(r2, FieldMemOperand(result, total_offset));
      }
    }
  
    if (has_elements) {
      // Copy elements backing store header.
      __ LoadHeapObject(source, elements);
      for (int i = 0; i < FixedArray::kHeaderSize; i += kPointerSize) {
        __ ldr(r2, FieldMemOperand(source, i));
        __ str(r2, FieldMemOperand(result, elements_offset + i));
      }
  
      // Copy elements backing store content.
      int elements_length = has_elements ? elements->length() : 0;
      if (elements->IsFixedDoubleArray()) {
        Handle<FixedDoubleArray> double_array =
            Handle<FixedDoubleArray>::cast(elements);
        for (int i = 0; i < elements_length; i++) {
          int64_t value = double_array->get_representation(i);
          // We only support little endian mode...
          int32_t value_low = value & 0xFFFFFFFF;
          int32_t value_high = value >> 32;
          int total_offset =
              elements_offset + FixedDoubleArray::OffsetOfElementAt(i);
          __ mov(r2, Operand(value_low));
          __ str(r2, FieldMemOperand(result, total_offset));
          __ mov(r2, Operand(value_high));
          __ str(r2, FieldMemOperand(result, total_offset + 4));
        }
      } else if (elements->IsFixedArray()) {
        for (int i = 0; i < elements_length; i++) {
          int total_offset = elements_offset + FixedArray::OffsetOfElementAt(i);
          Handle<Object> value = JSObject::GetElement(object, i);
          if (value->IsJSObject()) {
            Handle<JSObject> value_object = Handle<JSObject>::cast(value);
            __ add(r2, result, Operand(*offset));
            __ str(r2, FieldMemOperand(result, total_offset));
            __ LoadHeapObject(source, value_object);
            EmitDeepCopy(value_object, result, source, offset);
          } else if (value->IsHeapObject()) {
            __ LoadHeapObject(r2, Handle<HeapObject>::cast(value));
            __ str(r2, FieldMemOperand(result, total_offset));
          } else {
            __ mov(r2, Operand(value));
            __ str(r2, FieldMemOperand(result, total_offset));
          }
        }
      } else {
        UNREACHABLE();
      }
    }
  }
  
  
  void LCodeGen::DoFastLiteral(LFastLiteral* instr) {
    int size = instr->hydrogen()->total_size();
  
    // Allocate all objects that are part of the literal in one big
    // allocation. This avoids multiple limit checks.
    Label allocated, runtime_allocate;
    __ AllocateInNewSpace(size, r0, r2, r3, &runtime_allocate, TAG_OBJECT);
    __ jmp(&allocated);
  
    __ bind(&runtime_allocate);
    __ mov(r0, Operand(Smi::FromInt(size)));
    __ push(r0);
    CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);
  
    __ bind(&allocated);
    int offset = 0;
    __ LoadHeapObject(r1, instr->hydrogen()->boilerplate());
    EmitDeepCopy(instr->hydrogen()->boilerplate(), r0, r1, &offset);
    ASSERT_EQ(size, offset);
  }
  
  
  void LCodeGen::DoObjectLiteral(LObjectLiteral* instr) {
    Handle<FixedArray> literals(instr->environment()->closure()->literals());
    Handle<FixedArray> constant_properties =
        instr->hydrogen()->constant_properties();
  
    // Set up the parameters to the stub/runtime call.
    __ LoadHeapObject(r4, literals);
    __ mov(r3, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
    __ mov(r2, Operand(constant_properties));
    int flags = instr->hydrogen()->fast_elements()
        ? ObjectLiteral::kFastElements
        : ObjectLiteral::kNoFlags;
    __ mov(r1, Operand(Smi::FromInt(flags)));
    __ Push(r4, r3, r2, r1);
  
    // Pick the right runtime function or stub to call.
    int properties_count = constant_properties->length() / 2;
    if (instr->hydrogen()->depth() > 1) {
      CallRuntime(Runtime::kCreateObjectLiteral, 4, instr);
    } else if (flags != ObjectLiteral::kFastElements ||
        properties_count > FastCloneShallowObjectStub::kMaximumClonedProperties) {
      CallRuntime(Runtime::kCreateObjectLiteralShallow, 4, instr);
    } else {
      FastCloneShallowObjectStub stub(properties_count);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    }
  }
  
  
  void LCodeGen::DoToFastProperties(LToFastProperties* instr) {
    ASSERT(ToRegister(instr->InputAt(0)).is(r0));
    __ push(r0);
    CallRuntime(Runtime::kToFastProperties, 1, instr);
  }
  
  
  void LCodeGen::DoRegExpLiteral(LRegExpLiteral* instr) {
    Label materialized;
    // Registers will be used as follows:
    // r3 = JS function.
    // r7 = literals array.
    // r1 = regexp literal.
    // r0 = regexp literal clone.
    // r2 and r4-r6 are used as temporaries.
    __ ldr(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
    __ ldr(r7, FieldMemOperand(r3, JSFunction::kLiteralsOffset));
    int literal_offset = FixedArray::kHeaderSize +
        instr->hydrogen()->literal_index() * kPointerSize;
    __ ldr(r1, FieldMemOperand(r7, literal_offset));
    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
    __ cmp(r1, ip);
    __ b(ne, &materialized);
  
    // Create regexp literal using runtime function
    // Result will be in r0.
    __ mov(r6, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
    __ mov(r5, Operand(instr->hydrogen()->pattern()));
    __ mov(r4, Operand(instr->hydrogen()->flags()));
    __ Push(r7, r6, r5, r4);
    CallRuntime(Runtime::kMaterializeRegExpLiteral, 4, instr);
    __ mov(r1, r0);
  
    __ bind(&materialized);
    int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
    Label allocated, runtime_allocate;
  
    __ AllocateInNewSpace(size, r0, r2, r3, &runtime_allocate, TAG_OBJECT);
    __ jmp(&allocated);
  
    __ bind(&runtime_allocate);
    __ mov(r0, Operand(Smi::FromInt(size)));
    __ Push(r1, r0);
    CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);
    __ pop(r1);
  
    __ bind(&allocated);
    // Copy the content into the newly allocated memory.
    // (Unroll copy loop once for better throughput).
    for (int i = 0; i < size - kPointerSize; i += 2 * kPointerSize) {
      __ ldr(r3, FieldMemOperand(r1, i));
      __ ldr(r2, FieldMemOperand(r1, i + kPointerSize));
      __ str(r3, FieldMemOperand(r0, i));
      __ str(r2, FieldMemOperand(r0, i + kPointerSize));
    }
    if ((size % (2 * kPointerSize)) != 0) {
      __ ldr(r3, FieldMemOperand(r1, size - kPointerSize));
      __ str(r3, FieldMemOperand(r0, size - kPointerSize));
    }
  }
  
  
  void LCodeGen::DoFunctionLiteral(LFunctionLiteral* instr) {
    // Use the fast case closure allocation code that allocates in new
    // space for nested functions that don't need literals cloning.
    Handle<SharedFunctionInfo> shared_info = instr->shared_info();
    bool pretenure = instr->hydrogen()->pretenure();
    if (!pretenure && shared_info->num_literals() == 0) {
      FastNewClosureStub stub(shared_info->language_mode());
      __ mov(r1, Operand(shared_info));
      __ push(r1);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    } else {
      __ mov(r2, Operand(shared_info));
      __ mov(r1, Operand(pretenure
                         ? factory()->true_value()
                         : factory()->false_value()));
      __ Push(cp, r2, r1);
      CallRuntime(Runtime::kNewClosure, 3, instr);
    }
  }
  
  
  void LCodeGen::DoTypeof(LTypeof* instr) {
    Register input = ToRegister(instr->InputAt(0));
    __ push(input);
    CallRuntime(Runtime::kTypeof, 1, instr);
  }
  
  
  void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
    Register input = ToRegister(instr->InputAt(0));
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
    Label* true_label = chunk_->GetAssemblyLabel(true_block);
    Label* false_label = chunk_->GetAssemblyLabel(false_block);
  
    Condition final_branch_condition = EmitTypeofIs(true_label,
                                                    false_label,
                                                    input,
                                                    instr->type_literal());
    if (final_branch_condition != kNoCondition) {
      EmitBranch(true_block, false_block, final_branch_condition);
    }
  }
  
  
  Condition LCodeGen::EmitTypeofIs(Label* true_label,
                                   Label* false_label,
                                   Register input,
                                   Handle<String> type_name) {
    Condition final_branch_condition = kNoCondition;
    Register scratch = scratch0();
    if (type_name->Equals(heap()->number_symbol())) {
      __ JumpIfSmi(input, true_label);
      __ ldr(input, FieldMemOperand(input, HeapObject::kMapOffset));
      __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
      __ cmp(input, Operand(ip));
      final_branch_condition = eq;
  
    } else if (type_name->Equals(heap()->string_symbol())) {
      __ JumpIfSmi(input, false_label);
      __ CompareObjectType(input, input, scratch, FIRST_NONSTRING_TYPE);
      __ b(ge, false_label);
      __ ldrb(ip, FieldMemOperand(input, Map::kBitFieldOffset));
      __ tst(ip, Operand(1 << Map::kIsUndetectable));
      final_branch_condition = eq;
  
    } else if (type_name->Equals(heap()->boolean_symbol())) {
      __ CompareRoot(input, Heap::kTrueValueRootIndex);
      __ b(eq, true_label);
      __ CompareRoot(input, Heap::kFalseValueRootIndex);
      final_branch_condition = eq;
  
    } else if (FLAG_harmony_typeof && type_name->Equals(heap()->null_symbol())) {
      __ CompareRoot(input, Heap::kNullValueRootIndex);
      final_branch_condition = eq;
  
    } else if (type_name->Equals(heap()->undefined_symbol())) {
      __ CompareRoot(input, Heap::kUndefinedValueRootIndex);
      __ b(eq, true_label);
      __ JumpIfSmi(input, false_label);
      // Check for undetectable objects => true.
      __ ldr(input, FieldMemOperand(input, HeapObject::kMapOffset));
      __ ldrb(ip, FieldMemOperand(input, Map::kBitFieldOffset));
      __ tst(ip, Operand(1 << Map::kIsUndetectable));
      final_branch_condition = ne;
  
    } else if (type_name->Equals(heap()->function_symbol())) {
      STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
      __ JumpIfSmi(input, false_label);
      __ CompareObjectType(input, scratch, input, JS_FUNCTION_TYPE);
      __ b(eq, true_label);
      __ cmp(input, Operand(JS_FUNCTION_PROXY_TYPE));
      final_branch_condition = eq;
  
    } else if (type_name->Equals(heap()->object_symbol())) {
      __ JumpIfSmi(input, false_label);
      if (!FLAG_harmony_typeof) {
        __ CompareRoot(input, Heap::kNullValueRootIndex);
        __ b(eq, true_label);
      }
      __ CompareObjectType(input, input, scratch,
                           FIRST_NONCALLABLE_SPEC_OBJECT_TYPE);
      __ b(lt, false_label);
      __ CompareInstanceType(input, scratch, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
      __ b(gt, false_label);
      // Check for undetectable objects => false.
      __ ldrb(ip, FieldMemOperand(input, Map::kBitFieldOffset));
      __ tst(ip, Operand(1 << Map::kIsUndetectable));
      final_branch_condition = eq;
  
    } else {
      __ b(false_label);
    }
  
    return final_branch_condition;
  }
  
  
  void LCodeGen::DoIsConstructCallAndBranch(LIsConstructCallAndBranch* instr) {
    Register temp1 = ToRegister(instr->TempAt(0));
    int true_block = chunk_->LookupDestination(instr->true_block_id());
    int false_block = chunk_->LookupDestination(instr->false_block_id());
  
    EmitIsConstructCall(temp1, scratch0());
    EmitBranch(true_block, false_block, eq);
  }
  
  
  void LCodeGen::EmitIsConstructCall(Register temp1, Register temp2) {
    ASSERT(!temp1.is(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, Operand(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));
    __ cmp(temp1, Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
  }
  
  
  void LCodeGen::EnsureSpaceForLazyDeopt() {
    // Ensure that we have enough space after the previous lazy-bailout
    // instruction for patching the code here.
    int current_pc = masm()->pc_offset();
    int patch_size = Deoptimizer::patch_size();
    if (current_pc < last_lazy_deopt_pc_ + patch_size) {
      int padding_size = last_lazy_deopt_pc_ + patch_size - current_pc;
      ASSERT_EQ(0, padding_size % Assembler::kInstrSize);
      while (padding_size > 0) {
        __ nop();
        padding_size -= Assembler::kInstrSize;
      }
    }
    last_lazy_deopt_pc_ = masm()->pc_offset();
  }
  
  
  void LCodeGen::DoLazyBailout(LLazyBailout* instr) {
    EnsureSpaceForLazyDeopt();
    ASSERT(instr->HasEnvironment());
    LEnvironment* env = instr->environment();
    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
  }
  
  
  void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
    DeoptimizeIf(al, instr->environment());
  }
  
  
  void LCodeGen::DoDeleteProperty(LDeleteProperty* instr) {
    Register object = ToRegister(instr->object());
    Register key = ToRegister(instr->key());
    Register strict = scratch0();
    __ mov(strict, Operand(Smi::FromInt(strict_mode_flag())));
    __ Push(object, key, strict);
    ASSERT(instr->HasPointerMap() && instr->HasDeoptimizationEnvironment());
    LPointerMap* pointers = instr->pointer_map();
    RecordPosition(pointers->position());
    SafepointGenerator safepoint_generator(
        this, pointers, Safepoint::kLazyDeopt);
    __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION, safepoint_generator);
  }
  
  
  void LCodeGen::DoIn(LIn* instr) {
    Register obj = ToRegister(instr->object());
    Register key = ToRegister(instr->key());
    __ Push(key, obj);
    ASSERT(instr->HasPointerMap() && instr->HasDeoptimizationEnvironment());
    LPointerMap* pointers = instr->pointer_map();
    RecordPosition(pointers->position());
    SafepointGenerator safepoint_generator(this, pointers, Safepoint::kLazyDeopt);
    __ InvokeBuiltin(Builtins::IN, CALL_FUNCTION, safepoint_generator);
  }
  
  
  void LCodeGen::DoDeferredStackCheck(LStackCheck* instr) {
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
    __ CallRuntimeSaveDoubles(Runtime::kStackGuard);
    RecordSafepointWithLazyDeopt(
        instr, RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
    ASSERT(instr->HasEnvironment());
    LEnvironment* env = instr->environment();
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
  }
  
  
  void LCodeGen::DoStackCheck(LStackCheck* instr) {
    class DeferredStackCheck: public LDeferredCode {
     public:
      DeferredStackCheck(LCodeGen* codegen, LStackCheck* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() { codegen()->DoDeferredStackCheck(instr_); }
      virtual LInstruction* instr() { return instr_; }
     private:
      LStackCheck* instr_;
    };
  
    ASSERT(instr->HasEnvironment());
    LEnvironment* env = instr->environment();
    // There is no LLazyBailout instruction for stack-checks. We have to
    // prepare for lazy deoptimization explicitly here.
    if (instr->hydrogen()->is_function_entry()) {
      // Perform stack overflow check.
      Label done;
      __ LoadRoot(ip, Heap::kStackLimitRootIndex);
      __ cmp(sp, Operand(ip));
      __ b(hs, &done);
      StackCheckStub stub;
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      EnsureSpaceForLazyDeopt();
      __ bind(&done);
      RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
      safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
    } else {
      ASSERT(instr->hydrogen()->is_backwards_branch());
      // Perform stack overflow check if this goto needs it before jumping.
      DeferredStackCheck* deferred_stack_check =
          new DeferredStackCheck(this, instr);
      __ LoadRoot(ip, Heap::kStackLimitRootIndex);
      __ cmp(sp, Operand(ip));
      __ b(lo, deferred_stack_check->entry());
      EnsureSpaceForLazyDeopt();
      __ bind(instr->done_label());
      deferred_stack_check->SetExit(instr->done_label());
      RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
      // Don't record a deoptimization index for the safepoint here.
      // This will be done explicitly when emitting call and the safepoint in
      // the deferred code.
    }
  }
  
  
  void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
    // This is a pseudo-instruction that ensures that the environment here is
    // properly registered for deoptimization and records the assembler's PC
    // offset.
    LEnvironment* environment = instr->environment();
    environment->SetSpilledRegisters(instr->SpilledRegisterArray(),
                                     instr->SpilledDoubleRegisterArray());
  
    // If the environment were already registered, we would have no way of
    // backpatching it with the spill slot operands.
    ASSERT(!environment->HasBeenRegistered());
    RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
    ASSERT(osr_pc_offset_ == -1);
    osr_pc_offset_ = masm()->pc_offset();
  }
  
  
  void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
    __ cmp(r0, ip);
    DeoptimizeIf(eq, instr->environment());
  
    Register null_value = r5;
    __ LoadRoot(null_value, Heap::kNullValueRootIndex);
    __ cmp(r0, null_value);
    DeoptimizeIf(eq, instr->environment());
  
    __ tst(r0, Operand(kSmiTagMask));
    DeoptimizeIf(eq, instr->environment());
  
    STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
    __ CompareObjectType(r0, r1, r1, LAST_JS_PROXY_TYPE);
    DeoptimizeIf(le, instr->environment());
  
    Label use_cache, call_runtime;
    __ CheckEnumCache(null_value, &call_runtime);
  
    __ ldr(r0, FieldMemOperand(r0, HeapObject::kMapOffset));
    __ b(&use_cache);
  
    // Get the set of properties to enumerate.
    __ bind(&call_runtime);
    __ push(r0);
    CallRuntime(Runtime::kGetPropertyNamesFast, 1, instr);
  
    __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
    __ LoadRoot(ip, Heap::kMetaMapRootIndex);
    __ cmp(r1, ip);
    DeoptimizeIf(ne, instr->environment());
    __ bind(&use_cache);
  }
  
  
  void LCodeGen::DoForInCacheArray(LForInCacheArray* instr) {
    Register map = ToRegister(instr->map());
    Register result = ToRegister(instr->result());
    __ LoadInstanceDescriptors(map, result);
    __ ldr(result,
           FieldMemOperand(result, DescriptorArray::kEnumerationIndexOffset));
    __ ldr(result,
           FieldMemOperand(result, FixedArray::SizeFor(instr->idx())));
    __ cmp(result, Operand(0));
    DeoptimizeIf(eq, instr->environment());
  }
  
  
  void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
    Register object = ToRegister(instr->value());
    Register map = ToRegister(instr->map());
    __ ldr(scratch0(), FieldMemOperand(object, HeapObject::kMapOffset));
    __ cmp(map, scratch0());
    DeoptimizeIf(ne, instr->environment());
  }
  
  
  void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
    Register object = ToRegister(instr->object());
    Register index = ToRegister(instr->index());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
  
    Label out_of_object, done;
    __ cmp(index, Operand(0));
    __ b(lt, &out_of_object);
  
    STATIC_ASSERT(kPointerSizeLog2 > kSmiTagSize);
    __ add(scratch, object, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
    __ ldr(result, FieldMemOperand(scratch, 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(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
    __ ldr(result, FieldMemOperand(scratch,
                                   FixedArray::kHeaderSize - kPointerSize));
    __ bind(&done);
  }
  
  
  #undef __
  
  } }  // namespace v8::internal
  