text: // Copyright 2012 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "src/v8.h"
  
  #if V8_TARGET_ARCH_X64
  
  #include "src/code-factory.h"
  #include "src/code-stubs.h"
  #include "src/codegen.h"
  #include "src/compiler.h"
  #include "src/debug.h"
  #include "src/full-codegen.h"
  #include "src/ic/ic.h"
  #include "src/isolate-inl.h"
  #include "src/parser.h"
  #include "src/scopes.h"
  
  namespace v8 {
  namespace internal {
  
  #define __ ACCESS_MASM(masm_)
  
  
  class JumpPatchSite BASE_EMBEDDED {
   public:
    explicit JumpPatchSite(MacroAssembler* masm) : masm_(masm) {
  #ifdef DEBUG
      info_emitted_ = false;
  #endif
    }
  
    ~JumpPatchSite() {
      DCHECK(patch_site_.is_bound() == info_emitted_);
    }
  
    void EmitJumpIfNotSmi(Register reg,
                          Label* target,
                          Label::Distance near_jump = Label::kFar) {
      __ testb(reg, Immediate(kSmiTagMask));
      EmitJump(not_carry, target, near_jump);   // Always taken before patched.
    }
  
    void EmitJumpIfSmi(Register reg,
                       Label* target,
                       Label::Distance near_jump = Label::kFar) {
      __ testb(reg, Immediate(kSmiTagMask));
      EmitJump(carry, target, near_jump);  // Never taken before patched.
    }
  
    void EmitPatchInfo() {
      if (patch_site_.is_bound()) {
        int delta_to_patch_site = masm_->SizeOfCodeGeneratedSince(&patch_site_);
        DCHECK(is_uint8(delta_to_patch_site));
        __ testl(rax, Immediate(delta_to_patch_site));
  #ifdef DEBUG
        info_emitted_ = true;
  #endif
      } else {
        __ nop();  // Signals no inlined code.
      }
    }
  
   private:
    // jc will be patched with jz, jnc will become jnz.
    void EmitJump(Condition cc, Label* target, Label::Distance near_jump) {
      DCHECK(!patch_site_.is_bound() && !info_emitted_);
      DCHECK(cc == carry || cc == not_carry);
      __ bind(&patch_site_);
      __ j(cc, target, near_jump);
    }
  
    MacroAssembler* masm_;
    Label patch_site_;
  #ifdef DEBUG
    bool info_emitted_;
  #endif
  };
  
  
  // Generate code for a JS function.  On entry to the function the receiver
  // and arguments have been pushed on the stack left to right, with the
  // return address on top of them.  The actual argument count matches the
  // formal parameter count expected by the function.
  //
  // The live registers are:
  //   o rdi: the JS function object being called (i.e. ourselves)
  //   o rsi: our context
  //   o rbp: our caller's frame pointer
  //   o rsp: stack pointer (pointing to return address)
  //
  // The function builds a JS frame.  Please see JavaScriptFrameConstants in
  // frames-x64.h for its layout.
  void FullCodeGenerator::Generate() {
    CompilationInfo* info = info_;
    handler_table_ =
        isolate()->factory()->NewFixedArray(function()->handler_count(), TENURED);
  
    profiling_counter_ = isolate()->factory()->NewCell(
        Handle<Smi>(Smi::FromInt(FLAG_interrupt_budget), isolate()));
    SetFunctionPosition(function());
    Comment cmnt(masm_, "[ function compiled by full code generator");
  
    ProfileEntryHookStub::MaybeCallEntryHook(masm_);
  
  #ifdef DEBUG
    if (strlen(FLAG_stop_at) > 0 &&
        info->function()->name()->IsUtf8EqualTo(CStrVector(FLAG_stop_at))) {
      __ int3();
    }
  #endif
  
    // Sloppy mode functions and builtins need to replace the receiver with the
    // global proxy when called as functions (without an explicit receiver
    // object).
    if (info->strict_mode() == SLOPPY && !info->is_native()) {
      Label ok;
      // +1 for return address.
      StackArgumentsAccessor args(rsp, info->scope()->num_parameters());
      __ movp(rcx, args.GetReceiverOperand());
  
      __ CompareRoot(rcx, Heap::kUndefinedValueRootIndex);
      __ j(not_equal, &ok, Label::kNear);
  
      __ movp(rcx, GlobalObjectOperand());
      __ movp(rcx, FieldOperand(rcx, GlobalObject::kGlobalProxyOffset));
  
      __ movp(args.GetReceiverOperand(), rcx);
  
      __ bind(&ok);
    }
  
    // Open a frame scope to indicate that there is a frame on the stack.  The
    // MANUAL indicates that the scope shouldn't actually generate code to set up
    // the frame (that is done below).
    FrameScope frame_scope(masm_, StackFrame::MANUAL);
  
    info->set_prologue_offset(masm_->pc_offset());
    __ Prologue(info->IsCodePreAgingActive());
    info->AddNoFrameRange(0, masm_->pc_offset());
  
    { Comment cmnt(masm_, "[ Allocate locals");
      int locals_count = info->scope()->num_stack_slots();
      // Generators allocate locals, if any, in context slots.
      DCHECK(!info->function()->is_generator() || locals_count == 0);
      if (locals_count == 1) {
        __ PushRoot(Heap::kUndefinedValueRootIndex);
      } else if (locals_count > 1) {
        if (locals_count >= 128) {
          Label ok;
          __ movp(rcx, rsp);
          __ subp(rcx, Immediate(locals_count * kPointerSize));
          __ CompareRoot(rcx, Heap::kRealStackLimitRootIndex);
          __ j(above_equal, &ok, Label::kNear);
          __ InvokeBuiltin(Builtins::STACK_OVERFLOW, CALL_FUNCTION);
          __ bind(&ok);
        }
        __ LoadRoot(rdx, Heap::kUndefinedValueRootIndex);
        const int kMaxPushes = 32;
        if (locals_count >= kMaxPushes) {
          int loop_iterations = locals_count / kMaxPushes;
          __ movp(rcx, Immediate(loop_iterations));
          Label loop_header;
          __ bind(&loop_header);
          // Do pushes.
          for (int i = 0; i < kMaxPushes; i++) {
            __ Push(rdx);
          }
          // Continue loop if not done.
          __ decp(rcx);
          __ j(not_zero, &loop_header, Label::kNear);
        }
        int remaining = locals_count % kMaxPushes;
        // Emit the remaining pushes.
        for (int i  = 0; i < remaining; i++) {
          __ Push(rdx);
        }
      }
    }
  
    bool function_in_register = true;
  
    // Possibly allocate a local context.
    int heap_slots = info->scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
    if (heap_slots > 0) {
      Comment cmnt(masm_, "[ Allocate context");
      bool need_write_barrier = true;
      // Argument to NewContext is the function, which is still in rdi.
      if (FLAG_harmony_scoping && info->scope()->is_global_scope()) {
        __ Push(rdi);
        __ Push(info->scope()->GetScopeInfo());
        __ CallRuntime(Runtime::kNewGlobalContext, 2);
      } else if (heap_slots <= FastNewContextStub::kMaximumSlots) {
        FastNewContextStub stub(isolate(), heap_slots);
        __ CallStub(&stub);
        // Result of FastNewContextStub is always in new space.
        need_write_barrier = false;
      } else {
        __ Push(rdi);
        __ CallRuntime(Runtime::kNewFunctionContext, 1);
      }
      function_in_register = false;
      // Context is returned in rax.  It replaces the context passed to us.
      // It's saved in the stack and kept live in rsi.
      __ movp(rsi, rax);
      __ movp(Operand(rbp, StandardFrameConstants::kContextOffset), rax);
  
      // Copy any necessary parameters into the context.
      int num_parameters = info->scope()->num_parameters();
      for (int i = 0; i < num_parameters; i++) {
        Variable* var = scope()->parameter(i);
        if (var->IsContextSlot()) {
          int parameter_offset = StandardFrameConstants::kCallerSPOffset +
              (num_parameters - 1 - i) * kPointerSize;
          // Load parameter from stack.
          __ movp(rax, Operand(rbp, parameter_offset));
          // Store it in the context.
          int context_offset = Context::SlotOffset(var->index());
          __ movp(Operand(rsi, context_offset), rax);
          // Update the write barrier.  This clobbers rax and rbx.
          if (need_write_barrier) {
            __ RecordWriteContextSlot(
                rsi, context_offset, rax, rbx, kDontSaveFPRegs);
          } else if (FLAG_debug_code) {
            Label done;
            __ JumpIfInNewSpace(rsi, rax, &done, Label::kNear);
            __ Abort(kExpectedNewSpaceObject);
            __ bind(&done);
          }
        }
      }
    }
  
    // Possibly allocate an arguments object.
    Variable* arguments = scope()->arguments();
    if (arguments != NULL) {
      // Arguments object must be allocated after the context object, in
      // case the "arguments" or ".arguments" variables are in the context.
      Comment cmnt(masm_, "[ Allocate arguments object");
      if (function_in_register) {
        __ Push(rdi);
      } else {
        __ Push(Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
      }
      // The receiver is just before the parameters on the caller's stack.
      int num_parameters = info->scope()->num_parameters();
      int offset = num_parameters * kPointerSize;
      __ leap(rdx,
             Operand(rbp, StandardFrameConstants::kCallerSPOffset + offset));
      __ Push(rdx);
      __ Push(Smi::FromInt(num_parameters));
      // Arguments to ArgumentsAccessStub:
      //   function, receiver address, parameter count.
      // The stub will rewrite receiver and parameter count if the previous
      // stack frame was an arguments adapter frame.
      ArgumentsAccessStub::Type type;
      if (strict_mode() == STRICT) {
        type = ArgumentsAccessStub::NEW_STRICT;
      } else if (function()->has_duplicate_parameters()) {
        type = ArgumentsAccessStub::NEW_SLOPPY_SLOW;
      } else {
        type = ArgumentsAccessStub::NEW_SLOPPY_FAST;
      }
      ArgumentsAccessStub stub(isolate(), type);
      __ CallStub(&stub);
  
      SetVar(arguments, rax, rbx, rdx);
    }
  
    if (FLAG_trace) {
      __ CallRuntime(Runtime::kTraceEnter, 0);
    }
  
    // Visit the declarations and body unless there is an illegal
    // redeclaration.
    if (scope()->HasIllegalRedeclaration()) {
      Comment cmnt(masm_, "[ Declarations");
      scope()->VisitIllegalRedeclaration(this);
  
    } else {
      PrepareForBailoutForId(BailoutId::FunctionEntry(), NO_REGISTERS);
      { Comment cmnt(masm_, "[ Declarations");
        // For named function expressions, declare the function name as a
        // constant.
        if (scope()->is_function_scope() && scope()->function() != NULL) {
          VariableDeclaration* function = scope()->function();
          DCHECK(function->proxy()->var()->mode() == CONST ||
                 function->proxy()->var()->mode() == CONST_LEGACY);
          DCHECK(function->proxy()->var()->location() != Variable::UNALLOCATED);
          VisitVariableDeclaration(function);
        }
        VisitDeclarations(scope()->declarations());
      }
  
      { Comment cmnt(masm_, "[ Stack check");
        PrepareForBailoutForId(BailoutId::Declarations(), NO_REGISTERS);
         Label ok;
         __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
         __ j(above_equal, &ok, Label::kNear);
         __ call(isolate()->builtins()->StackCheck(), RelocInfo::CODE_TARGET);
         __ bind(&ok);
      }
  
      { Comment cmnt(masm_, "[ Body");
        DCHECK(loop_depth() == 0);
        VisitStatements(function()->body());
        DCHECK(loop_depth() == 0);
      }
    }
  
    // Always emit a 'return undefined' in case control fell off the end of
    // the body.
    { Comment cmnt(masm_, "[ return <undefined>;");
      __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
      EmitReturnSequence();
    }
  }
  
  
  void FullCodeGenerator::ClearAccumulator() {
    __ Set(rax, 0);
  }
  
  
  void FullCodeGenerator::EmitProfilingCounterDecrement(int delta) {
    __ Move(rbx, profiling_counter_, RelocInfo::EMBEDDED_OBJECT);
    __ SmiAddConstant(FieldOperand(rbx, Cell::kValueOffset),
                      Smi::FromInt(-delta));
  }
  
  
  void FullCodeGenerator::EmitProfilingCounterReset() {
    int reset_value = FLAG_interrupt_budget;
    __ Move(rbx, profiling_counter_, RelocInfo::EMBEDDED_OBJECT);
    __ Move(kScratchRegister, Smi::FromInt(reset_value));
    __ movp(FieldOperand(rbx, Cell::kValueOffset), kScratchRegister);
  }
  
  
  static const byte kJnsOffset = kPointerSize == kInt64Size ? 0x1d : 0x14;
  
  
  void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
                                                  Label* back_edge_target) {
    Comment cmnt(masm_, "[ Back edge bookkeeping");
    Label ok;
  
    DCHECK(back_edge_target->is_bound());
    int distance = masm_->SizeOfCodeGeneratedSince(back_edge_target);
    int weight = Min(kMaxBackEdgeWeight,
                     Max(1, distance / kCodeSizeMultiplier));
    EmitProfilingCounterDecrement(weight);
  
    __ j(positive, &ok, Label::kNear);
    {
      PredictableCodeSizeScope predictible_code_size_scope(masm_, kJnsOffset);
      DontEmitDebugCodeScope dont_emit_debug_code_scope(masm_);
      __ call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
  
      // Record a mapping of this PC offset to the OSR id.  This is used to find
      // the AST id from the unoptimized code in order to use it as a key into
      // the deoptimization input data found in the optimized code.
      RecordBackEdge(stmt->OsrEntryId());
  
      EmitProfilingCounterReset();
    }
    __ bind(&ok);
  
    PrepareForBailoutForId(stmt->EntryId(), NO_REGISTERS);
    // Record a mapping of the OSR id to this PC.  This is used if the OSR
    // entry becomes the target of a bailout.  We don't expect it to be, but
    // we want it to work if it is.
    PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
  }
  
  
  void FullCodeGenerator::EmitReturnSequence() {
    Comment cmnt(masm_, "[ Return sequence");
    if (return_label_.is_bound()) {
      __ jmp(&return_label_);
    } else {
      __ bind(&return_label_);
      if (FLAG_trace) {
        __ Push(rax);
        __ CallRuntime(Runtime::kTraceExit, 1);
      }
      // Pretend that the exit is a backwards jump to the entry.
      int weight = 1;
      if (info_->ShouldSelfOptimize()) {
        weight = FLAG_interrupt_budget / FLAG_self_opt_count;
      } else {
        int distance = masm_->pc_offset();
        weight = Min(kMaxBackEdgeWeight,
                     Max(1, distance / kCodeSizeMultiplier));
      }
      EmitProfilingCounterDecrement(weight);
      Label ok;
      __ j(positive, &ok, Label::kNear);
      __ Push(rax);
      __ call(isolate()->builtins()->InterruptCheck(),
              RelocInfo::CODE_TARGET);
      __ Pop(rax);
      EmitProfilingCounterReset();
      __ bind(&ok);
  #ifdef DEBUG
      // Add a label for checking the size of the code used for returning.
      Label check_exit_codesize;
      masm_->bind(&check_exit_codesize);
  #endif
      CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
      __ RecordJSReturn();
      // Do not use the leave instruction here because it is too short to
      // patch with the code required by the debugger.
      __ movp(rsp, rbp);
      __ popq(rbp);
      int no_frame_start = masm_->pc_offset();
  
      int arguments_bytes = (info_->scope()->num_parameters() + 1) * kPointerSize;
      __ Ret(arguments_bytes, rcx);
  
      // Add padding that will be overwritten by a debugger breakpoint.  We
      // have just generated at least 7 bytes: "movp rsp, rbp; pop rbp; ret k"
      // (3 + 1 + 3) for x64 and at least 6 (2 + 1 + 3) bytes for x32.
      const int kPadding = Assembler::kJSReturnSequenceLength -
                           kPointerSize == kInt64Size ? 7 : 6;
      for (int i = 0; i < kPadding; ++i) {
        masm_->int3();
      }
      // Check that the size of the code used for returning is large enough
      // for the debugger's requirements.
      DCHECK(Assembler::kJSReturnSequenceLength <=
             masm_->SizeOfCodeGeneratedSince(&check_exit_codesize));
  
      info_->AddNoFrameRange(no_frame_start, masm_->pc_offset());
    }
  }
  
  
  void FullCodeGenerator::EffectContext::Plug(Variable* var) const {
    DCHECK(var->IsStackAllocated() || var->IsContextSlot());
  }
  
  
  void FullCodeGenerator::AccumulatorValueContext::Plug(Variable* var) const {
    DCHECK(var->IsStackAllocated() || var->IsContextSlot());
    codegen()->GetVar(result_register(), var);
  }
  
  
  void FullCodeGenerator::StackValueContext::Plug(Variable* var) const {
    DCHECK(var->IsStackAllocated() || var->IsContextSlot());
    MemOperand operand = codegen()->VarOperand(var, result_register());
    __ Push(operand);
  }
  
  
  void FullCodeGenerator::TestContext::Plug(Variable* var) const {
    codegen()->GetVar(result_register(), var);
    codegen()->PrepareForBailoutBeforeSplit(condition(), false, NULL, NULL);
    codegen()->DoTest(this);
  }
  
  
  void FullCodeGenerator::EffectContext::Plug(Heap::RootListIndex index) const {
  }
  
  
  void FullCodeGenerator::AccumulatorValueContext::Plug(
      Heap::RootListIndex index) const {
    __ LoadRoot(result_register(), index);
  }
  
  
  void FullCodeGenerator::StackValueContext::Plug(
      Heap::RootListIndex index) const {
    __ PushRoot(index);
  }
  
  
  void FullCodeGenerator::TestContext::Plug(Heap::RootListIndex index) const {
    codegen()->PrepareForBailoutBeforeSplit(condition(),
                                            true,
                                            true_label_,
                                            false_label_);
    if (index == Heap::kUndefinedValueRootIndex ||
        index == Heap::kNullValueRootIndex ||
        index == Heap::kFalseValueRootIndex) {
      if (false_label_ != fall_through_) __ jmp(false_label_);
    } else if (index == Heap::kTrueValueRootIndex) {
      if (true_label_ != fall_through_) __ jmp(true_label_);
    } else {
      __ LoadRoot(result_register(), index);
      codegen()->DoTest(this);
    }
  }
  
  
  void FullCodeGenerator::EffectContext::Plug(Handle<Object> lit) const {
  }
  
  
  void FullCodeGenerator::AccumulatorValueContext::Plug(
      Handle<Object> lit) const {
    if (lit->IsSmi()) {
      __ SafeMove(result_register(), Smi::cast(*lit));
    } else {
      __ Move(result_register(), lit);
    }
  }
  
  
  void FullCodeGenerator::StackValueContext::Plug(Handle<Object> lit) const {
    if (lit->IsSmi()) {
      __ SafePush(Smi::cast(*lit));
    } else {
      __ Push(lit);
    }
  }
  
  
  void FullCodeGenerator::TestContext::Plug(Handle<Object> lit) const {
    codegen()->PrepareForBailoutBeforeSplit(condition(),
                                            true,
                                            true_label_,
                                            false_label_);
    DCHECK(!lit->IsUndetectableObject());  // There are no undetectable literals.
    if (lit->IsUndefined() || lit->IsNull() || lit->IsFalse()) {
      if (false_label_ != fall_through_) __ jmp(false_label_);
    } else if (lit->IsTrue() || lit->IsJSObject()) {
      if (true_label_ != fall_through_) __ jmp(true_label_);
    } else if (lit->IsString()) {
      if (String::cast(*lit)->length() == 0) {
        if (false_label_ != fall_through_) __ jmp(false_label_);
      } else {
        if (true_label_ != fall_through_) __ jmp(true_label_);
      }
    } else if (lit->IsSmi()) {
      if (Smi::cast(*lit)->value() == 0) {
        if (false_label_ != fall_through_) __ jmp(false_label_);
      } else {
        if (true_label_ != fall_through_) __ jmp(true_label_);
      }
    } else {
      // For simplicity we always test the accumulator register.
      __ Move(result_register(), lit);
      codegen()->DoTest(this);
    }
  }
  
  
  void FullCodeGenerator::EffectContext::DropAndPlug(int count,
                                                     Register reg) const {
    DCHECK(count > 0);
    __ Drop(count);
  }
  
  
  void FullCodeGenerator::AccumulatorValueContext::DropAndPlug(
      int count,
      Register reg) const {
    DCHECK(count > 0);
    __ Drop(count);
    __ Move(result_register(), reg);
  }
  
  
  void FullCodeGenerator::StackValueContext::DropAndPlug(int count,
                                                         Register reg) const {
    DCHECK(count > 0);
    if (count > 1) __ Drop(count - 1);
    __ movp(Operand(rsp, 0), reg);
  }
  
  
  void FullCodeGenerator::TestContext::DropAndPlug(int count,
                                                   Register reg) const {
    DCHECK(count > 0);
    // For simplicity we always test the accumulator register.
    __ Drop(count);
    __ Move(result_register(), reg);
    codegen()->PrepareForBailoutBeforeSplit(condition(), false, NULL, NULL);
    codegen()->DoTest(this);
  }
  
  
  void FullCodeGenerator::EffectContext::Plug(Label* materialize_true,
                                              Label* materialize_false) const {
    DCHECK(materialize_true == materialize_false);
    __ bind(materialize_true);
  }
  
  
  void FullCodeGenerator::AccumulatorValueContext::Plug(
      Label* materialize_true,
      Label* materialize_false) const {
    Label done;
    __ bind(materialize_true);
    __ Move(result_register(), isolate()->factory()->true_value());
    __ jmp(&done, Label::kNear);
    __ bind(materialize_false);
    __ Move(result_register(), isolate()->factory()->false_value());
    __ bind(&done);
  }
  
  
  void FullCodeGenerator::StackValueContext::Plug(
      Label* materialize_true,
      Label* materialize_false) const {
    Label done;
    __ bind(materialize_true);
    __ Push(isolate()->factory()->true_value());
    __ jmp(&done, Label::kNear);
    __ bind(materialize_false);
    __ Push(isolate()->factory()->false_value());
    __ bind(&done);
  }
  
  
  void FullCodeGenerator::TestContext::Plug(Label* materialize_true,
                                            Label* materialize_false) const {
    DCHECK(materialize_true == true_label_);
    DCHECK(materialize_false == false_label_);
  }
  
  
  void FullCodeGenerator::EffectContext::Plug(bool flag) const {
  }
  
  
  void FullCodeGenerator::AccumulatorValueContext::Plug(bool flag) const {
    Heap::RootListIndex value_root_index =
        flag ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex;
    __ LoadRoot(result_register(), value_root_index);
  }
  
  
  void FullCodeGenerator::StackValueContext::Plug(bool flag) const {
    Heap::RootListIndex value_root_index =
        flag ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex;
    __ PushRoot(value_root_index);
  }
  
  
  void FullCodeGenerator::TestContext::Plug(bool flag) const {
    codegen()->PrepareForBailoutBeforeSplit(condition(),
                                            true,
                                            true_label_,
                                            false_label_);
    if (flag) {
      if (true_label_ != fall_through_) __ jmp(true_label_);
    } else {
      if (false_label_ != fall_through_) __ jmp(false_label_);
    }
  }
  
  
  void FullCodeGenerator::DoTest(Expression* condition,
                                 Label* if_true,
                                 Label* if_false,
                                 Label* fall_through) {
    Handle<Code> ic = ToBooleanStub::GetUninitialized(isolate());
    CallIC(ic, condition->test_id());
    __ testp(result_register(), result_register());
    // The stub returns nonzero for true.
    Split(not_zero, if_true, if_false, fall_through);
  }
  
  
  void FullCodeGenerator::Split(Condition cc,
                                Label* if_true,
                                Label* if_false,
                                Label* fall_through) {
    if (if_false == fall_through) {
      __ j(cc, if_true);
    } else if (if_true == fall_through) {
      __ j(NegateCondition(cc), if_false);
    } else {
      __ j(cc, if_true);
      __ jmp(if_false);
    }
  }
  
  
  MemOperand FullCodeGenerator::StackOperand(Variable* var) {
    DCHECK(var->IsStackAllocated());
    // Offset is negative because higher indexes are at lower addresses.
    int offset = -var->index() * kPointerSize;
    // Adjust by a (parameter or local) base offset.
    if (var->IsParameter()) {
      offset += kFPOnStackSize + kPCOnStackSize +
                (info_->scope()->num_parameters() - 1) * kPointerSize;
    } else {
      offset += JavaScriptFrameConstants::kLocal0Offset;
    }
    return Operand(rbp, offset);
  }
  
  
  MemOperand FullCodeGenerator::VarOperand(Variable* var, Register scratch) {
    DCHECK(var->IsContextSlot() || var->IsStackAllocated());
    if (var->IsContextSlot()) {
      int context_chain_length = scope()->ContextChainLength(var->scope());
      __ LoadContext(scratch, context_chain_length);
      return ContextOperand(scratch, var->index());
    } else {
      return StackOperand(var);
    }
  }
  
  
  void FullCodeGenerator::GetVar(Register dest, Variable* var) {
    DCHECK(var->IsContextSlot() || var->IsStackAllocated());
    MemOperand location = VarOperand(var, dest);
    __ movp(dest, location);
  }
  
  
  void FullCodeGenerator::SetVar(Variable* var,
                                 Register src,
                                 Register scratch0,
                                 Register scratch1) {
    DCHECK(var->IsContextSlot() || var->IsStackAllocated());
    DCHECK(!scratch0.is(src));
    DCHECK(!scratch0.is(scratch1));
    DCHECK(!scratch1.is(src));
    MemOperand location = VarOperand(var, scratch0);
    __ movp(location, src);
  
    // Emit the write barrier code if the location is in the heap.
    if (var->IsContextSlot()) {
      int offset = Context::SlotOffset(var->index());
      __ RecordWriteContextSlot(scratch0, offset, src, scratch1, kDontSaveFPRegs);
    }
  }
  
  
  void FullCodeGenerator::PrepareForBailoutBeforeSplit(Expression* expr,
                                                       bool should_normalize,
                                                       Label* if_true,
                                                       Label* if_false) {
    // Only prepare for bailouts before splits if we're in a test
    // context. Otherwise, we let the Visit function deal with the
    // preparation to avoid preparing with the same AST id twice.
    if (!context()->IsTest() || !info_->IsOptimizable()) return;
  
    Label skip;
    if (should_normalize) __ jmp(&skip, Label::kNear);
    PrepareForBailout(expr, TOS_REG);
    if (should_normalize) {
      __ CompareRoot(rax, Heap::kTrueValueRootIndex);
      Split(equal, if_true, if_false, NULL);
      __ bind(&skip);
    }
  }
  
  
  void FullCodeGenerator::EmitDebugCheckDeclarationContext(Variable* variable) {
    // The variable in the declaration always resides in the current context.
    DCHECK_EQ(0, scope()->ContextChainLength(variable->scope()));
    if (generate_debug_code_) {
      // Check that we're not inside a with or catch context.
      __ movp(rbx, FieldOperand(rsi, HeapObject::kMapOffset));
      __ CompareRoot(rbx, Heap::kWithContextMapRootIndex);
      __ Check(not_equal, kDeclarationInWithContext);
      __ CompareRoot(rbx, Heap::kCatchContextMapRootIndex);
      __ Check(not_equal, kDeclarationInCatchContext);
    }
  }
  
  
  void FullCodeGenerator::VisitVariableDeclaration(
      VariableDeclaration* declaration) {
    // If it was not possible to allocate the variable at compile time, we
    // need to "declare" it at runtime to make sure it actually exists in the
    // local context.
    VariableProxy* proxy = declaration->proxy();
    VariableMode mode = declaration->mode();
    Variable* variable = proxy->var();
    bool hole_init = mode == LET || mode == CONST || mode == CONST_LEGACY;
    switch (variable->location()) {
      case Variable::UNALLOCATED:
        globals_->Add(variable->name(), zone());
        globals_->Add(variable->binding_needs_init()
                          ? isolate()->factory()->the_hole_value()
                      : isolate()->factory()->undefined_value(),
                      zone());
        break;
  
      case Variable::PARAMETER:
      case Variable::LOCAL:
        if (hole_init) {
          Comment cmnt(masm_, "[ VariableDeclaration");
          __ LoadRoot(kScratchRegister, Heap::kTheHoleValueRootIndex);
          __ movp(StackOperand(variable), kScratchRegister);
        }
        break;
  
      case Variable::CONTEXT:
        if (hole_init) {
          Comment cmnt(masm_, "[ VariableDeclaration");
          EmitDebugCheckDeclarationContext(variable);
          __ LoadRoot(kScratchRegister, Heap::kTheHoleValueRootIndex);
          __ movp(ContextOperand(rsi, variable->index()), kScratchRegister);
          // No write barrier since the hole value is in old space.
          PrepareForBailoutForId(proxy->id(), NO_REGISTERS);
        }
        break;
  
      case Variable::LOOKUP: {
        Comment cmnt(masm_, "[ VariableDeclaration");
        __ Push(rsi);
        __ Push(variable->name());
        // Declaration nodes are always introduced in one of four modes.
        DCHECK(IsDeclaredVariableMode(mode));
        PropertyAttributes attr =
            IsImmutableVariableMode(mode) ? READ_ONLY : NONE;
        __ Push(Smi::FromInt(attr));
        // Push initial value, if any.
        // Note: For variables we must not push an initial value (such as
        // 'undefined') because we may have a (legal) redeclaration and we
        // must not destroy the current value.
        if (hole_init) {
          __ PushRoot(Heap::kTheHoleValueRootIndex);
        } else {
          __ Push(Smi::FromInt(0));  // Indicates no initial value.
        }
        __ CallRuntime(Runtime::kDeclareLookupSlot, 4);
        break;
      }
    }
  }
  
  
  void FullCodeGenerator::VisitFunctionDeclaration(
      FunctionDeclaration* declaration) {
    VariableProxy* proxy = declaration->proxy();
    Variable* variable = proxy->var();
    switch (variable->location()) {
      case Variable::UNALLOCATED: {
        globals_->Add(variable->name(), zone());
        Handle<SharedFunctionInfo> function =
            Compiler::BuildFunctionInfo(declaration->fun(), script(), info_);
        // Check for stack-overflow exception.
        if (function.is_null()) return SetStackOverflow();
        globals_->Add(function, zone());
        break;
      }
  
      case Variable::PARAMETER:
      case Variable::LOCAL: {
        Comment cmnt(masm_, "[ FunctionDeclaration");
        VisitForAccumulatorValue(declaration->fun());
        __ movp(StackOperand(variable), result_register());
        break;
      }
  
      case Variable::CONTEXT: {
        Comment cmnt(masm_, "[ FunctionDeclaration");
        EmitDebugCheckDeclarationContext(variable);
        VisitForAccumulatorValue(declaration->fun());
        __ movp(ContextOperand(rsi, variable->index()), result_register());
        int offset = Context::SlotOffset(variable->index());
        // We know that we have written a function, which is not a smi.
        __ RecordWriteContextSlot(rsi,
                                  offset,
                                  result_register(),
                                  rcx,
                                  kDontSaveFPRegs,
                                  EMIT_REMEMBERED_SET,
                                  OMIT_SMI_CHECK);
        PrepareForBailoutForId(proxy->id(), NO_REGISTERS);
        break;
      }
  
      case Variable::LOOKUP: {
        Comment cmnt(masm_, "[ FunctionDeclaration");
        __ Push(rsi);
        __ Push(variable->name());
        __ Push(Smi::FromInt(NONE));
        VisitForStackValue(declaration->fun());
        __ CallRuntime(Runtime::kDeclareLookupSlot, 4);
        break;
      }
    }
  }
  
  
  void FullCodeGenerator::VisitModuleDeclaration(ModuleDeclaration* declaration) {
    Variable* variable = declaration->proxy()->var();
    DCHECK(variable->location() == Variable::CONTEXT);
    DCHECK(variable->interface()->IsFrozen());
  
    Comment cmnt(masm_, "[ ModuleDeclaration");
    EmitDebugCheckDeclarationContext(variable);
  
    // Load instance object.
    __ LoadContext(rax, scope_->ContextChainLength(scope_->GlobalScope()));
    __ movp(rax, ContextOperand(rax, variable->interface()->Index()));
    __ movp(rax, ContextOperand(rax, Context::EXTENSION_INDEX));
  
    // Assign it.
    __ movp(ContextOperand(rsi, variable->index()), rax);
    // We know that we have written a module, which is not a smi.
    __ RecordWriteContextSlot(rsi,
                              Context::SlotOffset(variable->index()),
                              rax,
                              rcx,
                              kDontSaveFPRegs,
                              EMIT_REMEMBERED_SET,
                              OMIT_SMI_CHECK);
    PrepareForBailoutForId(declaration->proxy()->id(), NO_REGISTERS);
  
    // Traverse into body.
    Visit(declaration->module());
  }
  
  
  void FullCodeGenerator::VisitImportDeclaration(ImportDeclaration* declaration) {
    VariableProxy* proxy = declaration->proxy();
    Variable* variable = proxy->var();
    switch (variable->location()) {
      case Variable::UNALLOCATED:
        // TODO(rossberg)
        break;
  
      case Variable::CONTEXT: {
        Comment cmnt(masm_, "[ ImportDeclaration");
        EmitDebugCheckDeclarationContext(variable);
        // TODO(rossberg)
        break;
      }
  
      case Variable::PARAMETER:
      case Variable::LOCAL:
      case Variable::LOOKUP:
        UNREACHABLE();
    }
  }
  
  
  void FullCodeGenerator::VisitExportDeclaration(ExportDeclaration* declaration) {
    // TODO(rossberg)
  }
  
  
  void FullCodeGenerator::DeclareGlobals(Handle<FixedArray> pairs) {
    // Call the runtime to declare the globals.
    __ Push(rsi);  // The context is the first argument.
    __ Push(pairs);
    __ Push(Smi::FromInt(DeclareGlobalsFlags()));
    __ CallRuntime(Runtime::kDeclareGlobals, 3);
    // Return value is ignored.
  }
  
  
  void FullCodeGenerator::DeclareModules(Handle<FixedArray> descriptions) {
    // Call the runtime to declare the modules.
    __ Push(descriptions);
    __ CallRuntime(Runtime::kDeclareModules, 1);
    // Return value is ignored.
  }
  
  
  void FullCodeGenerator::VisitSwitchStatement(SwitchStatement* stmt) {
    Comment cmnt(masm_, "[ SwitchStatement");
    Breakable nested_statement(this, stmt);
    SetStatementPosition(stmt);
  
    // Keep the switch value on the stack until a case matches.
    VisitForStackValue(stmt->tag());
    PrepareForBailoutForId(stmt->EntryId(), NO_REGISTERS);
  
    ZoneList<CaseClause*>* clauses = stmt->cases();
    CaseClause* default_clause = NULL;  // Can occur anywhere in the list.
  
    Label next_test;  // Recycled for each test.
    // Compile all the tests with branches to their bodies.
    for (int i = 0; i < clauses->length(); i++) {
      CaseClause* clause = clauses->at(i);
      clause->body_target()->Unuse();
  
      // The default is not a test, but remember it as final fall through.
      if (clause->is_default()) {
        default_clause = clause;
        continue;
      }
  
      Comment cmnt(masm_, "[ Case comparison");
      __ bind(&next_test);
      next_test.Unuse();
  
      // Compile the label expression.
      VisitForAccumulatorValue(clause->label());
  
      // Perform the comparison as if via '==='.
      __ movp(rdx, Operand(rsp, 0));  // Switch value.
      bool inline_smi_code = ShouldInlineSmiCase(Token::EQ_STRICT);
      JumpPatchSite patch_site(masm_);
      if (inline_smi_code) {
        Label slow_case;
        __ movp(rcx, rdx);
        __ orp(rcx, rax);
        patch_site.EmitJumpIfNotSmi(rcx, &slow_case, Label::kNear);
  
        __ cmpp(rdx, rax);
        __ j(not_equal, &next_test);
        __ Drop(1);  // Switch value is no longer needed.
        __ jmp(clause->body_target());
        __ bind(&slow_case);
      }
  
      // Record position before stub call for type feedback.
      SetSourcePosition(clause->position());
      Handle<Code> ic =
          CodeFactory::CompareIC(isolate(), Token::EQ_STRICT).code();
      CallIC(ic, clause->CompareId());
      patch_site.EmitPatchInfo();
  
      Label skip;
      __ jmp(&skip, Label::kNear);
      PrepareForBailout(clause, TOS_REG);
      __ CompareRoot(rax, Heap::kTrueValueRootIndex);
      __ j(not_equal, &next_test);
      __ Drop(1);
      __ jmp(clause->body_target());
      __ bind(&skip);
  
      __ testp(rax, rax);
      __ j(not_equal, &next_test);
      __ Drop(1);  // Switch value is no longer needed.
      __ jmp(clause->body_target());
    }
  
    // Discard the test value and jump to the default if present, otherwise to
    // the end of the statement.
    __ bind(&next_test);
    __ Drop(1);  // Switch value is no longer needed.
    if (default_clause == NULL) {
      __ jmp(nested_statement.break_label());
    } else {
      __ jmp(default_clause->body_target());
    }
  
    // Compile all the case bodies.
    for (int i = 0; i < clauses->length(); i++) {
      Comment cmnt(masm_, "[ Case body");
      CaseClause* clause = clauses->at(i);
      __ bind(clause->body_target());
      PrepareForBailoutForId(clause->EntryId(), NO_REGISTERS);
      VisitStatements(clause->statements());
    }
  
    __ bind(nested_statement.break_label());
    PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
  }
  
  
  void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
    Comment cmnt(masm_, "[ ForInStatement");
    FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
    SetStatementPosition(stmt);
  
    Label loop, exit;
    ForIn loop_statement(this, stmt);
    increment_loop_depth();
  
    // Get the object to enumerate over. If the object is null or undefined, skip
    // over the loop.  See ECMA-262 version 5, section 12.6.4.
    VisitForAccumulatorValue(stmt->enumerable());
    __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
    __ j(equal, &exit);
    Register null_value = rdi;
    __ LoadRoot(null_value, Heap::kNullValueRootIndex);
    __ cmpp(rax, null_value);
    __ j(equal, &exit);
  
    PrepareForBailoutForId(stmt->PrepareId(), TOS_REG);
  
    // Convert the object to a JS object.
    Label convert, done_convert;
    __ JumpIfSmi(rax, &convert);
    __ CmpObjectType(rax, FIRST_SPEC_OBJECT_TYPE, rcx);
    __ j(above_equal, &done_convert);
    __ bind(&convert);
    __ Push(rax);
    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
    __ bind(&done_convert);
    __ Push(rax);
  
    // Check for proxies.
    Label call_runtime;
    STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
    __ CmpObjectType(rax, LAST_JS_PROXY_TYPE, rcx);
    __ j(below_equal, &call_runtime);
  
    // Check cache validity in generated code. This is a fast case for
    // the JSObject::IsSimpleEnum cache validity checks. If we cannot
    // guarantee cache validity, call the runtime system to check cache
    // validity or get the property names in a fixed array.
    __ CheckEnumCache(null_value, &call_runtime);
  
    // The enum cache is valid.  Load the map of the object being
    // iterated over and use the cache for the iteration.
    Label use_cache;
    __ movp(rax, FieldOperand(rax, HeapObject::kMapOffset));
    __ jmp(&use_cache, Label::kNear);
  
    // Get the set of properties to enumerate.
    __ bind(&call_runtime);
    __ Push(rax);  // Duplicate the enumerable object on the stack.
    __ CallRuntime(Runtime::kGetPropertyNamesFast, 1);
  
    // If we got a map from the runtime call, we can do a fast
    // modification check. Otherwise, we got a fixed array, and we have
    // to do a slow check.
    Label fixed_array;
    __ CompareRoot(FieldOperand(rax, HeapObject::kMapOffset),
                   Heap::kMetaMapRootIndex);
    __ j(not_equal, &fixed_array);
  
    // We got a map in register rax. Get the enumeration cache from it.
    __ bind(&use_cache);
  
    Label no_descriptors;
  
    __ EnumLength(rdx, rax);
    __ Cmp(rdx, Smi::FromInt(0));
    __ j(equal, &no_descriptors);
  
    __ LoadInstanceDescriptors(rax, rcx);
    __ movp(rcx, FieldOperand(rcx, DescriptorArray::kEnumCacheOffset));
    __ movp(rcx, FieldOperand(rcx, DescriptorArray::kEnumCacheBridgeCacheOffset));
  
    // Set up the four remaining stack slots.
    __ Push(rax);  // Map.
    __ Push(rcx);  // Enumeration cache.
    __ Push(rdx);  // Number of valid entries for the map in the enum cache.
    __ Push(Smi::FromInt(0));  // Initial index.
    __ jmp(&loop);
  
    __ bind(&no_descriptors);
    __ addp(rsp, Immediate(kPointerSize));
    __ jmp(&exit);
  
    // We got a fixed array in register rax. Iterate through that.
    Label non_proxy;
    __ bind(&fixed_array);
  
    // No need for a write barrier, we are storing a Smi in the feedback vector.
    __ Move(rbx, FeedbackVector());
    __ Move(FieldOperand(rbx, FixedArray::OffsetOfElementAt(slot.ToInt())),
            TypeFeedbackVector::MegamorphicSentinel(isolate()));
    __ Move(rbx, Smi::FromInt(1));  // Smi indicates slow check
    __ movp(rcx, Operand(rsp, 0 * kPointerSize));  // Get enumerated object
    STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
    __ CmpObjectType(rcx, LAST_JS_PROXY_TYPE, rcx);
    __ j(above, &non_proxy);
    __ Move(rbx, Smi::FromInt(0));  // Zero indicates proxy
    __ bind(&non_proxy);
    __ Push(rbx);  // Smi
    __ Push(rax);  // Array
    __ movp(rax, FieldOperand(rax, FixedArray::kLengthOffset));
    __ Push(rax);  // Fixed array length (as smi).
    __ Push(Smi::FromInt(0));  // Initial index.
  
    // Generate code for doing the condition check.
    PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
    __ bind(&loop);
    __ movp(rax, Operand(rsp, 0 * kPointerSize));  // Get the current index.
    __ cmpp(rax, Operand(rsp, 1 * kPointerSize));  // Compare to the array length.
    __ j(above_equal, loop_statement.break_label());
  
    // Get the current entry of the array into register rbx.
    __ movp(rbx, Operand(rsp, 2 * kPointerSize));
    SmiIndex index = masm()->SmiToIndex(rax, rax, kPointerSizeLog2);
    __ movp(rbx, FieldOperand(rbx,
                              index.reg,
                              index.scale,
                              FixedArray::kHeaderSize));
  
    // Get the expected map from the stack or a smi in the
    // permanent slow case into register rdx.
    __ movp(rdx, Operand(rsp, 3 * kPointerSize));
  
    // Check if the expected map still matches that of the enumerable.
    // If not, we may have to filter the key.
    Label update_each;
    __ movp(rcx, Operand(rsp, 4 * kPointerSize));
    __ cmpp(rdx, FieldOperand(rcx, HeapObject::kMapOffset));
    __ j(equal, &update_each, Label::kNear);
  
    // For proxies, no filtering is done.
    // TODO(rossberg): What if only a prototype is a proxy? Not specified yet.
    __ Cmp(rdx, Smi::FromInt(0));
    __ j(equal, &update_each, Label::kNear);
  
    // Convert the entry to a string or null if it isn't a property
    // anymore. If the property has been removed while iterating, we
    // just skip it.
    __ Push(rcx);  // Enumerable.
    __ Push(rbx);  // Current entry.
    __ InvokeBuiltin(Builtins::FILTER_KEY, CALL_FUNCTION);
    __ Cmp(rax, Smi::FromInt(0));
    __ j(equal, loop_statement.continue_label());
    __ movp(rbx, rax);
  
    // Update the 'each' property or variable from the possibly filtered
    // entry in register rbx.
    __ bind(&update_each);
    __ movp(result_register(), rbx);
    // Perform the assignment as if via '='.
    { EffectContext context(this);
      EmitAssignment(stmt->each());
    }
  
    // Generate code for the body of the loop.
    Visit(stmt->body());
  
    // Generate code for going to the next element by incrementing the
    // index (smi) stored on top of the stack.
    __ bind(loop_statement.continue_label());
    __ SmiAddConstant(Operand(rsp, 0 * kPointerSize), Smi::FromInt(1));
  
    EmitBackEdgeBookkeeping(stmt, &loop);
    __ jmp(&loop);
  
    // Remove the pointers stored on the stack.
    __ bind(loop_statement.break_label());
    __ addp(rsp, Immediate(5 * kPointerSize));
  
    // Exit and decrement the loop depth.
    PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
    __ bind(&exit);
    decrement_loop_depth();
  }
  
  
  void FullCodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
    Comment cmnt(masm_, "[ ForOfStatement");
    SetStatementPosition(stmt);
  
    Iteration loop_statement(this, stmt);
    increment_loop_depth();
  
    // var iterator = iterable[Symbol.iterator]();
    VisitForEffect(stmt->assign_iterator());
  
    // Loop entry.
    __ bind(loop_statement.continue_label());
  
    // result = iterator.next()
    VisitForEffect(stmt->next_result());
  
    // if (result.done) break;
    Label result_not_done;
    VisitForControl(stmt->result_done(),
                    loop_statement.break_label(),
                    &result_not_done,
                    &result_not_done);
    __ bind(&result_not_done);
  
    // each = result.value
    VisitForEffect(stmt->assign_each());
  
    // Generate code for the body of the loop.
    Visit(stmt->body());
  
    // Check stack before looping.
    PrepareForBailoutForId(stmt->BackEdgeId(), NO_REGISTERS);
    EmitBackEdgeBookkeeping(stmt, loop_statement.continue_label());
    __ jmp(loop_statement.continue_label());
  
    // Exit and decrement the loop depth.
    PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
    __ bind(loop_statement.break_label());
    decrement_loop_depth();
  }
  
  
  void FullCodeGenerator::EmitNewClosure(Handle<SharedFunctionInfo> info,
                                         bool pretenure) {
    // Use the fast case closure allocation code that allocates in new
    // space for nested functions that don't need literals cloning. If
    // we're running with the --always-opt or the --prepare-always-opt
    // flag, we need to use the runtime function so that the new function
    // we are creating here gets a chance to have its code optimized and
    // doesn't just get a copy of the existing unoptimized code.
    if (!FLAG_always_opt &&
        !FLAG_prepare_always_opt &&
        !pretenure &&
        scope()->is_function_scope() &&
        info->num_literals() == 0) {
      FastNewClosureStub stub(isolate(), info->strict_mode(), info->kind());
      __ Move(rbx, info);
      __ CallStub(&stub);
    } else {
      __ Push(rsi);
      __ Push(info);
      __ Push(pretenure
              ? isolate()->factory()->true_value()
              : isolate()->factory()->false_value());
      __ CallRuntime(Runtime::kNewClosure, 3);
    }
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::VisitVariableProxy(VariableProxy* expr) {
    Comment cmnt(masm_, "[ VariableProxy");
    EmitVariableLoad(expr);
  }
  
  
  void FullCodeGenerator::EmitLoadHomeObject(SuperReference* expr) {
    Comment cnmt(masm_, "[ SuperReference ");
  
    __ movp(LoadDescriptor::ReceiverRegister(),
            Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
  
    Handle<Symbol> home_object_symbol(isolate()->heap()->home_object_symbol());
    __ Move(LoadDescriptor::NameRegister(), home_object_symbol);
  
    if (FLAG_vector_ics) {
      __ Move(VectorLoadICDescriptor::SlotRegister(),
              SmiFromSlot(expr->HomeObjectFeedbackSlot()));
      CallLoadIC(NOT_CONTEXTUAL);
    } else {
      CallLoadIC(NOT_CONTEXTUAL, expr->HomeObjectFeedbackId());
    }
  
  
    __ Cmp(rax, isolate()->factory()->undefined_value());
    Label done;
    __ j(not_equal, &done);
    __ CallRuntime(Runtime::kThrowNonMethodError, 0);
    __ bind(&done);
  }
  
  
  void FullCodeGenerator::EmitLoadGlobalCheckExtensions(VariableProxy* proxy,
                                                        TypeofState typeof_state,
                                                        Label* slow) {
    Register context = rsi;
    Register temp = rdx;
  
    Scope* s = scope();
    while (s != NULL) {
      if (s->num_heap_slots() > 0) {
        if (s->calls_sloppy_eval()) {
          // Check that extension is NULL.
          __ cmpp(ContextOperand(context, Context::EXTENSION_INDEX),
                  Immediate(0));
          __ j(not_equal, slow);
        }
        // Load next context in chain.
        __ movp(temp, ContextOperand(context, Context::PREVIOUS_INDEX));
        // Walk the rest of the chain without clobbering rsi.
        context = temp;
      }
      // If no outer scope calls eval, we do not need to check more
      // context extensions.  If we have reached an eval scope, we check
      // all extensions from this point.
      if (!s->outer_scope_calls_sloppy_eval() || s->is_eval_scope()) break;
      s = s->outer_scope();
    }
  
    if (s != NULL && s->is_eval_scope()) {
      // Loop up the context chain.  There is no frame effect so it is
      // safe to use raw labels here.
      Label next, fast;
      if (!context.is(temp)) {
        __ movp(temp, context);
      }
      // Load map for comparison into register, outside loop.
      __ LoadRoot(kScratchRegister, Heap::kNativeContextMapRootIndex);
      __ bind(&next);
      // Terminate at native context.
      __ cmpp(kScratchRegister, FieldOperand(temp, HeapObject::kMapOffset));
      __ j(equal, &fast, Label::kNear);
      // Check that extension is NULL.
      __ cmpp(ContextOperand(temp, Context::EXTENSION_INDEX), Immediate(0));
      __ j(not_equal, slow);
      // Load next context in chain.
      __ movp(temp, ContextOperand(temp, Context::PREVIOUS_INDEX));
      __ jmp(&next);
      __ bind(&fast);
    }
  
    // All extension objects were empty and it is safe to use a global
    // load IC call.
    __ movp(LoadDescriptor::ReceiverRegister(), GlobalObjectOperand());
    __ Move(LoadDescriptor::NameRegister(), proxy->var()->name());
    if (FLAG_vector_ics) {
      __ Move(VectorLoadICDescriptor::SlotRegister(),
              SmiFromSlot(proxy->VariableFeedbackSlot()));
    }
  
    ContextualMode mode = (typeof_state == INSIDE_TYPEOF)
        ? NOT_CONTEXTUAL
        : CONTEXTUAL;
    CallLoadIC(mode);
  }
  
  
  MemOperand FullCodeGenerator::ContextSlotOperandCheckExtensions(Variable* var,
                                                                  Label* slow) {
    DCHECK(var->IsContextSlot());
    Register context = rsi;
    Register temp = rbx;
  
    for (Scope* s = scope(); s != var->scope(); s = s->outer_scope()) {
      if (s->num_heap_slots() > 0) {
        if (s->calls_sloppy_eval()) {
          // Check that extension is NULL.
          __ cmpp(ContextOperand(context, Context::EXTENSION_INDEX),
                  Immediate(0));
          __ j(not_equal, slow);
        }
        __ movp(temp, ContextOperand(context, Context::PREVIOUS_INDEX));
        // Walk the rest of the chain without clobbering rsi.
        context = temp;
      }
    }
    // Check that last extension is NULL.
    __ cmpp(ContextOperand(context, Context::EXTENSION_INDEX), Immediate(0));
    __ j(not_equal, slow);
  
    // This function is used only for loads, not stores, so it's safe to
    // return an rsi-based operand (the write barrier cannot be allowed to
    // destroy the rsi register).
    return ContextOperand(context, var->index());
  }
  
  
  void FullCodeGenerator::EmitDynamicLookupFastCase(VariableProxy* proxy,
                                                    TypeofState typeof_state,
                                                    Label* slow,
                                                    Label* done) {
    // Generate fast-case code for variables that might be shadowed by
    // eval-introduced variables.  Eval is used a lot without
    // introducing variables.  In those cases, we do not want to
    // perform a runtime call for all variables in the scope
    // containing the eval.
    Variable* var = proxy->var();
    if (var->mode() == DYNAMIC_GLOBAL) {
      EmitLoadGlobalCheckExtensions(proxy, typeof_state, slow);
      __ jmp(done);
    } else if (var->mode() == DYNAMIC_LOCAL) {
      Variable* local = var->local_if_not_shadowed();
      __ movp(rax, ContextSlotOperandCheckExtensions(local, slow));
      if (local->mode() == LET || local->mode() == CONST ||
          local->mode() == CONST_LEGACY) {
        __ CompareRoot(rax, Heap::kTheHoleValueRootIndex);
        __ j(not_equal, done);
        if (local->mode() == CONST_LEGACY) {
          __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
        } else {  // LET || CONST
          __ Push(var->name());
          __ CallRuntime(Runtime::kThrowReferenceError, 1);
        }
      }
      __ jmp(done);
    }
  }
  
  
  void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
    // Record position before possible IC call.
    SetSourcePosition(proxy->position());
    Variable* var = proxy->var();
  
    // Three cases: global variables, lookup variables, and all other types of
    // variables.
    switch (var->location()) {
      case Variable::UNALLOCATED: {
        Comment cmnt(masm_, "[ Global variable");
        __ Move(LoadDescriptor::NameRegister(), var->name());
        __ movp(LoadDescriptor::ReceiverRegister(), GlobalObjectOperand());
        if (FLAG_vector_ics) {
          __ Move(VectorLoadICDescriptor::SlotRegister(),
                  SmiFromSlot(proxy->VariableFeedbackSlot()));
        }
        CallLoadIC(CONTEXTUAL);
        context()->Plug(rax);
        break;
      }
  
      case Variable::PARAMETER:
      case Variable::LOCAL:
      case Variable::CONTEXT: {
        Comment cmnt(masm_, var->IsContextSlot() ? "[ Context slot"
                                                 : "[ Stack slot");
        if (var->binding_needs_init()) {
          // var->scope() may be NULL when the proxy is located in eval code and
          // refers to a potential outside binding. Currently those bindings are
          // always looked up dynamically, i.e. in that case
          //     var->location() == LOOKUP.
          // always holds.
          DCHECK(var->scope() != NULL);
  
          // Check if the binding really needs an initialization check. The check
          // can be skipped in the following situation: we have a LET or CONST
          // binding in harmony mode, both the Variable and the VariableProxy have
          // the same declaration scope (i.e. they are both in global code, in the
          // same function or in the same eval code) and the VariableProxy is in
          // the source physically located after the initializer of the variable.
          //
          // We cannot skip any initialization checks for CONST in non-harmony
          // mode because const variables may be declared but never initialized:
          //   if (false) { const x; }; var y = x;
          //
          // The condition on the declaration scopes is a conservative check for
          // nested functions that access a binding and are called before the
          // binding is initialized:
          //   function() { f(); let x = 1; function f() { x = 2; } }
          //
          bool skip_init_check;
          if (var->scope()->DeclarationScope() != scope()->DeclarationScope()) {
            skip_init_check = false;
          } else {
            // Check that we always have valid source position.
            DCHECK(var->initializer_position() != RelocInfo::kNoPosition);
            DCHECK(proxy->position() != RelocInfo::kNoPosition);
            skip_init_check = var->mode() != CONST_LEGACY &&
                var->initializer_position() < proxy->position();
          }
  
          if (!skip_init_check) {
            // Let and const need a read barrier.
            Label done;
            GetVar(rax, var);
            __ CompareRoot(rax, Heap::kTheHoleValueRootIndex);
            __ j(not_equal, &done, Label::kNear);
            if (var->mode() == LET || var->mode() == CONST) {
              // Throw a reference error when using an uninitialized let/const
              // binding in harmony mode.
              __ Push(var->name());
              __ CallRuntime(Runtime::kThrowReferenceError, 1);
            } else {
              // Uninitalized const bindings outside of harmony mode are unholed.
              DCHECK(var->mode() == CONST_LEGACY);
              __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
            }
            __ bind(&done);
            context()->Plug(rax);
            break;
          }
        }
        context()->Plug(var);
        break;
      }
  
      case Variable::LOOKUP: {
        Comment cmnt(masm_, "[ Lookup slot");
        Label done, slow;
        // Generate code for loading from variables potentially shadowed
        // by eval-introduced variables.
        EmitDynamicLookupFastCase(proxy, NOT_INSIDE_TYPEOF, &slow, &done);
        __ bind(&slow);
        __ Push(rsi);  // Context.
        __ Push(var->name());
        __ CallRuntime(Runtime::kLoadLookupSlot, 2);
        __ bind(&done);
        context()->Plug(rax);
        break;
      }
    }
  }
  
  
  void FullCodeGenerator::VisitRegExpLiteral(RegExpLiteral* expr) {
    Comment cmnt(masm_, "[ RegExpLiteral");
    Label materialized;
    // Registers will be used as follows:
    // rdi = JS function.
    // rcx = literals array.
    // rbx = regexp literal.
    // rax = regexp literal clone.
    __ movp(rdi, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
    __ movp(rcx, FieldOperand(rdi, JSFunction::kLiteralsOffset));
    int literal_offset =
        FixedArray::kHeaderSize + expr->literal_index() * kPointerSize;
    __ movp(rbx, FieldOperand(rcx, literal_offset));
    __ CompareRoot(rbx, Heap::kUndefinedValueRootIndex);
    __ j(not_equal, &materialized, Label::kNear);
  
    // Create regexp literal using runtime function
    // Result will be in rax.
    __ Push(rcx);
    __ Push(Smi::FromInt(expr->literal_index()));
    __ Push(expr->pattern());
    __ Push(expr->flags());
    __ CallRuntime(Runtime::kMaterializeRegExpLiteral, 4);
    __ movp(rbx, rax);
  
    __ bind(&materialized);
    int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
    Label allocated, runtime_allocate;
    __ Allocate(size, rax, rcx, rdx, &runtime_allocate, TAG_OBJECT);
    __ jmp(&allocated);
  
    __ bind(&runtime_allocate);
    __ Push(rbx);
    __ Push(Smi::FromInt(size));
    __ CallRuntime(Runtime::kAllocateInNewSpace, 1);
    __ Pop(rbx);
  
    __ bind(&allocated);
    // Copy the content into the newly allocated memory.
    // (Unroll copy loop once for better throughput).
    for (int i = 0; i < size - kPointerSize; i += 2 * kPointerSize) {
      __ movp(rdx, FieldOperand(rbx, i));
      __ movp(rcx, FieldOperand(rbx, i + kPointerSize));
      __ movp(FieldOperand(rax, i), rdx);
      __ movp(FieldOperand(rax, i + kPointerSize), rcx);
    }
    if ((size % (2 * kPointerSize)) != 0) {
      __ movp(rdx, FieldOperand(rbx, size - kPointerSize));
      __ movp(FieldOperand(rax, size - kPointerSize), rdx);
    }
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitAccessor(Expression* expression) {
    if (expression == NULL) {
      __ PushRoot(Heap::kNullValueRootIndex);
    } else {
      VisitForStackValue(expression);
    }
  }
  
  
  void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
    Comment cmnt(masm_, "[ ObjectLiteral");
  
    expr->BuildConstantProperties(isolate());
    Handle<FixedArray> constant_properties = expr->constant_properties();
    int flags = expr->fast_elements()
        ? ObjectLiteral::kFastElements
        : ObjectLiteral::kNoFlags;
    flags |= expr->has_function()
        ? ObjectLiteral::kHasFunction
        : ObjectLiteral::kNoFlags;
    int properties_count = constant_properties->length() / 2;
    if (expr->may_store_doubles() || expr->depth() > 1 ||
        masm()->serializer_enabled() || flags != ObjectLiteral::kFastElements ||
        properties_count > FastCloneShallowObjectStub::kMaximumClonedProperties) {
      __ movp(rdi, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
      __ Push(FieldOperand(rdi, JSFunction::kLiteralsOffset));
      __ Push(Smi::FromInt(expr->literal_index()));
      __ Push(constant_properties);
      __ Push(Smi::FromInt(flags));
      __ CallRuntime(Runtime::kCreateObjectLiteral, 4);
    } else {
      __ movp(rdi, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
      __ movp(rax, FieldOperand(rdi, JSFunction::kLiteralsOffset));
      __ Move(rbx, Smi::FromInt(expr->literal_index()));
      __ Move(rcx, constant_properties);
      __ Move(rdx, Smi::FromInt(flags));
      FastCloneShallowObjectStub stub(isolate(), properties_count);
      __ CallStub(&stub);
    }
  
    // If result_saved is true the result is on top of the stack.  If
    // result_saved is false the result is in rax.
    bool result_saved = false;
  
    // Mark all computed expressions that are bound to a key that
    // is shadowed by a later occurrence of the same key. For the
    // marked expressions, no store code is emitted.
    expr->CalculateEmitStore(zone());
  
    AccessorTable accessor_table(zone());
    for (int i = 0; i < expr->properties()->length(); i++) {
      ObjectLiteral::Property* property = expr->properties()->at(i);
      if (property->IsCompileTimeValue()) continue;
  
      Literal* key = property->key();
      Expression* value = property->value();
      if (!result_saved) {
        __ Push(rax);  // Save result on the stack
        result_saved = true;
      }
      switch (property->kind()) {
        case ObjectLiteral::Property::CONSTANT:
          UNREACHABLE();
        case ObjectLiteral::Property::MATERIALIZED_LITERAL:
          DCHECK(!CompileTimeValue::IsCompileTimeValue(value));
          // Fall through.
        case ObjectLiteral::Property::COMPUTED:
          if (key->value()->IsInternalizedString()) {
            if (property->emit_store()) {
              VisitForAccumulatorValue(value);
              DCHECK(StoreDescriptor::ValueRegister().is(rax));
              __ Move(StoreDescriptor::NameRegister(), key->value());
              __ movp(StoreDescriptor::ReceiverRegister(), Operand(rsp, 0));
              CallStoreIC(key->LiteralFeedbackId());
              PrepareForBailoutForId(key->id(), NO_REGISTERS);
            } else {
              VisitForEffect(value);
            }
            break;
          }
          __ Push(Operand(rsp, 0));  // Duplicate receiver.
          VisitForStackValue(key);
          VisitForStackValue(value);
          if (property->emit_store()) {
            __ Push(Smi::FromInt(SLOPPY));  // Strict mode
            __ CallRuntime(Runtime::kSetProperty, 4);
          } else {
            __ Drop(3);
          }
          break;
        case ObjectLiteral::Property::PROTOTYPE:
          __ Push(Operand(rsp, 0));  // Duplicate receiver.
          VisitForStackValue(value);
          if (property->emit_store()) {
            __ CallRuntime(Runtime::kSetPrototype, 2);
          } else {
            __ Drop(2);
          }
          break;
        case ObjectLiteral::Property::GETTER:
          accessor_table.lookup(key)->second->getter = value;
          break;
        case ObjectLiteral::Property::SETTER:
          accessor_table.lookup(key)->second->setter = value;
          break;
      }
    }
  
    // Emit code to define accessors, using only a single call to the runtime for
    // each pair of corresponding getters and setters.
    for (AccessorTable::Iterator it = accessor_table.begin();
         it != accessor_table.end();
         ++it) {
      __ Push(Operand(rsp, 0));  // Duplicate receiver.
      VisitForStackValue(it->first);
      EmitAccessor(it->second->getter);
      EmitAccessor(it->second->setter);
      __ Push(Smi::FromInt(NONE));
      __ CallRuntime(Runtime::kDefineAccessorPropertyUnchecked, 5);
    }
  
    if (expr->has_function()) {
      DCHECK(result_saved);
      __ Push(Operand(rsp, 0));
      __ CallRuntime(Runtime::kToFastProperties, 1);
    }
  
    if (result_saved) {
      context()->PlugTOS();
    } else {
      context()->Plug(rax);
    }
  }
  
  
  void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
    Comment cmnt(masm_, "[ ArrayLiteral");
  
    expr->BuildConstantElements(isolate());
    int flags = expr->depth() == 1
        ? ArrayLiteral::kShallowElements
        : ArrayLiteral::kNoFlags;
  
    ZoneList<Expression*>* subexprs = expr->values();
    int length = subexprs->length();
    Handle<FixedArray> constant_elements = expr->constant_elements();
    DCHECK_EQ(2, constant_elements->length());
    ElementsKind constant_elements_kind =
        static_cast<ElementsKind>(Smi::cast(constant_elements->get(0))->value());
    bool has_constant_fast_elements =
        IsFastObjectElementsKind(constant_elements_kind);
    Handle<FixedArrayBase> constant_elements_values(
        FixedArrayBase::cast(constant_elements->get(1)));
  
    AllocationSiteMode allocation_site_mode = TRACK_ALLOCATION_SITE;
    if (has_constant_fast_elements && !FLAG_allocation_site_pretenuring) {
      // If the only customer of allocation sites is transitioning, then
      // we can turn it off if we don't have anywhere else to transition to.
      allocation_site_mode = DONT_TRACK_ALLOCATION_SITE;
    }
  
    if (expr->depth() > 1 || length > JSObject::kInitialMaxFastElementArray) {
      __ movp(rbx, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
      __ Push(FieldOperand(rbx, JSFunction::kLiteralsOffset));
      __ Push(Smi::FromInt(expr->literal_index()));
      __ Push(constant_elements);
      __ Push(Smi::FromInt(flags));
      __ CallRuntime(Runtime::kCreateArrayLiteral, 4);
    } else {
      __ movp(rbx, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
      __ movp(rax, FieldOperand(rbx, JSFunction::kLiteralsOffset));
      __ Move(rbx, Smi::FromInt(expr->literal_index()));
      __ Move(rcx, constant_elements);
      FastCloneShallowArrayStub stub(isolate(), allocation_site_mode);
      __ CallStub(&stub);
    }
  
    bool result_saved = false;  // Is the result saved to the stack?
  
    // Emit code to evaluate all the non-constant subexpressions and to store
    // them into the newly cloned array.
    for (int i = 0; i < length; i++) {
      Expression* subexpr = subexprs->at(i);
      // If the subexpression is a literal or a simple materialized literal it
      // is already set in the cloned array.
      if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;
  
      if (!result_saved) {
        __ Push(rax);  // array literal
        __ Push(Smi::FromInt(expr->literal_index()));
        result_saved = true;
      }
      VisitForAccumulatorValue(subexpr);
  
      if (IsFastObjectElementsKind(constant_elements_kind)) {
        // Fast-case array literal with ElementsKind of FAST_*_ELEMENTS, they
        // cannot transition and don't need to call the runtime stub.
        int offset = FixedArray::kHeaderSize + (i * kPointerSize);
        __ movp(rbx, Operand(rsp, kPointerSize));  // Copy of array literal.
        __ movp(rbx, FieldOperand(rbx, JSObject::kElementsOffset));
        // Store the subexpression value in the array's elements.
        __ movp(FieldOperand(rbx, offset), result_register());
        // Update the write barrier for the array store.
        __ RecordWriteField(rbx, offset, result_register(), rcx,
                            kDontSaveFPRegs,
                            EMIT_REMEMBERED_SET,
                            INLINE_SMI_CHECK);
      } else {
        // Store the subexpression value in the array's elements.
        __ Move(rcx, Smi::FromInt(i));
        StoreArrayLiteralElementStub stub(isolate());
        __ CallStub(&stub);
      }
  
      PrepareForBailoutForId(expr->GetIdForElement(i), NO_REGISTERS);
    }
  
    if (result_saved) {
      __ addp(rsp, Immediate(kPointerSize));  // literal index
      context()->PlugTOS();
    } else {
      context()->Plug(rax);
    }
  }
  
  
  void FullCodeGenerator::VisitAssignment(Assignment* expr) {
    DCHECK(expr->target()->IsValidReferenceExpression());
  
    Comment cmnt(masm_, "[ Assignment");
  
    Property* property = expr->target()->AsProperty();
    LhsKind assign_type = GetAssignType(property);
  
    // Evaluate LHS expression.
    switch (assign_type) {
      case VARIABLE:
        // Nothing to do here.
        break;
      case NAMED_PROPERTY:
        if (expr->is_compound()) {
          // We need the receiver both on the stack and in the register.
          VisitForStackValue(property->obj());
          __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, 0));
        } else {
          VisitForStackValue(property->obj());
        }
        break;
      case NAMED_SUPER_PROPERTY:
        VisitForStackValue(property->obj()->AsSuperReference()->this_var());
        EmitLoadHomeObject(property->obj()->AsSuperReference());
        __ Push(result_register());
        if (expr->is_compound()) {
          __ Push(MemOperand(rsp, kPointerSize));
          __ Push(result_register());
        }
        break;
      case KEYED_SUPER_PROPERTY:
        VisitForStackValue(property->obj()->AsSuperReference()->this_var());
        EmitLoadHomeObject(property->obj()->AsSuperReference());
        __ Push(result_register());
        VisitForAccumulatorValue(property->key());
        __ Push(result_register());
        if (expr->is_compound()) {
          __ Push(MemOperand(rsp, 2 * kPointerSize));
          __ Push(MemOperand(rsp, 2 * kPointerSize));
          __ Push(result_register());
        }
        break;
      case KEYED_PROPERTY: {
        if (expr->is_compound()) {
          VisitForStackValue(property->obj());
          VisitForStackValue(property->key());
          __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, kPointerSize));
          __ movp(LoadDescriptor::NameRegister(), Operand(rsp, 0));
        } else {
          VisitForStackValue(property->obj());
          VisitForStackValue(property->key());
        }
        break;
      }
    }
  
    // For compound assignments we need another deoptimization point after the
    // variable/property load.
    if (expr->is_compound()) {
      { AccumulatorValueContext context(this);
        switch (assign_type) {
          case VARIABLE:
            EmitVariableLoad(expr->target()->AsVariableProxy());
            PrepareForBailout(expr->target(), TOS_REG);
            break;
          case NAMED_PROPERTY:
            EmitNamedPropertyLoad(property);
            PrepareForBailoutForId(property->LoadId(), TOS_REG);
            break;
          case NAMED_SUPER_PROPERTY:
            EmitNamedSuperPropertyLoad(property);
            PrepareForBailoutForId(property->LoadId(), TOS_REG);
            break;
          case KEYED_SUPER_PROPERTY:
            EmitKeyedSuperPropertyLoad(property);
            PrepareForBailoutForId(property->LoadId(), TOS_REG);
            break;
          case KEYED_PROPERTY:
            EmitKeyedPropertyLoad(property);
            PrepareForBailoutForId(property->LoadId(), TOS_REG);
            break;
        }
      }
  
      Token::Value op = expr->binary_op();
      __ Push(rax);  // Left operand goes on the stack.
      VisitForAccumulatorValue(expr->value());
  
      OverwriteMode mode = expr->value()->ResultOverwriteAllowed()
          ? OVERWRITE_RIGHT
          : NO_OVERWRITE;
      SetSourcePosition(expr->position() + 1);
      AccumulatorValueContext context(this);
      if (ShouldInlineSmiCase(op)) {
        EmitInlineSmiBinaryOp(expr->binary_operation(),
                              op,
                              mode,
                              expr->target(),
                              expr->value());
      } else {
        EmitBinaryOp(expr->binary_operation(), op, mode);
      }
      // Deoptimization point in case the binary operation may have side effects.
      PrepareForBailout(expr->binary_operation(), TOS_REG);
    } else {
      VisitForAccumulatorValue(expr->value());
    }
  
    // Record source position before possible IC call.
    SetSourcePosition(expr->position());
  
    // Store the value.
    switch (assign_type) {
      case VARIABLE:
        EmitVariableAssignment(expr->target()->AsVariableProxy()->var(),
                               expr->op());
        PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
        context()->Plug(rax);
        break;
      case NAMED_PROPERTY:
        EmitNamedPropertyAssignment(expr);
        break;
      case NAMED_SUPER_PROPERTY:
        EmitNamedSuperPropertyStore(property);
        context()->Plug(rax);
        break;
      case KEYED_SUPER_PROPERTY:
        EmitKeyedSuperPropertyStore(property);
        context()->Plug(rax);
        break;
      case KEYED_PROPERTY:
        EmitKeyedPropertyAssignment(expr);
        break;
    }
  }
  
  
  void FullCodeGenerator::VisitYield(Yield* expr) {
    Comment cmnt(masm_, "[ Yield");
    // Evaluate yielded value first; the initial iterator definition depends on
    // this.  It stays on the stack while we update the iterator.
    VisitForStackValue(expr->expression());
  
    switch (expr->yield_kind()) {
      case Yield::kSuspend:
        // Pop value from top-of-stack slot; box result into result register.
        EmitCreateIteratorResult(false);
        __ Push(result_register());
        // Fall through.
      case Yield::kInitial: {
        Label suspend, continuation, post_runtime, resume;
  
        __ jmp(&suspend);
  
        __ bind(&continuation);
        __ jmp(&resume);
  
        __ bind(&suspend);
        VisitForAccumulatorValue(expr->generator_object());
        DCHECK(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
        __ Move(FieldOperand(rax, JSGeneratorObject::kContinuationOffset),
                Smi::FromInt(continuation.pos()));
        __ movp(FieldOperand(rax, JSGeneratorObject::kContextOffset), rsi);
        __ movp(rcx, rsi);
        __ RecordWriteField(rax, JSGeneratorObject::kContextOffset, rcx, rdx,
                            kDontSaveFPRegs);
        __ leap(rbx, Operand(rbp, StandardFrameConstants::kExpressionsOffset));
        __ cmpp(rsp, rbx);
        __ j(equal, &post_runtime);
        __ Push(rax);  // generator object
        __ CallRuntime(Runtime::kSuspendJSGeneratorObject, 1);
        __ movp(context_register(),
                Operand(rbp, StandardFrameConstants::kContextOffset));
        __ bind(&post_runtime);
  
        __ Pop(result_register());
        EmitReturnSequence();
  
        __ bind(&resume);
        context()->Plug(result_register());
        break;
      }
  
      case Yield::kFinal: {
        VisitForAccumulatorValue(expr->generator_object());
        __ Move(FieldOperand(result_register(),
                             JSGeneratorObject::kContinuationOffset),
                Smi::FromInt(JSGeneratorObject::kGeneratorClosed));
        // Pop value from top-of-stack slot, box result into result register.
        EmitCreateIteratorResult(true);
        EmitUnwindBeforeReturn();
        EmitReturnSequence();
        break;
      }
  
      case Yield::kDelegating: {
        VisitForStackValue(expr->generator_object());
  
        // Initial stack layout is as follows:
        // [sp + 1 * kPointerSize] iter
        // [sp + 0 * kPointerSize] g
  
        Label l_catch, l_try, l_suspend, l_continuation, l_resume;
        Label l_next, l_call, l_loop;
        Register load_receiver = LoadDescriptor::ReceiverRegister();
        Register load_name = LoadDescriptor::NameRegister();
  
        // Initial send value is undefined.
        __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
        __ jmp(&l_next);
  
        // catch (e) { receiver = iter; f = 'throw'; arg = e; goto l_call; }
        __ bind(&l_catch);
        handler_table()->set(expr->index(), Smi::FromInt(l_catch.pos()));
        __ LoadRoot(load_name, Heap::kthrow_stringRootIndex);  // "throw"
        __ Push(load_name);
        __ Push(Operand(rsp, 2 * kPointerSize));               // iter
        __ Push(rax);                                          // exception
        __ jmp(&l_call);
  
        // try { received = %yield result }
        // Shuffle the received result above a try handler and yield it without
        // re-boxing.
        __ bind(&l_try);
        __ Pop(rax);                                       // result
        __ PushTryHandler(StackHandler::CATCH, expr->index());
        const int handler_size = StackHandlerConstants::kSize;
        __ Push(rax);                                      // result
        __ jmp(&l_suspend);
        __ bind(&l_continuation);
        __ jmp(&l_resume);
        __ bind(&l_suspend);
        const int generator_object_depth = kPointerSize + handler_size;
        __ movp(rax, Operand(rsp, generator_object_depth));
        __ Push(rax);                                      // g
        DCHECK(l_continuation.pos() > 0 && Smi::IsValid(l_continuation.pos()));
        __ Move(FieldOperand(rax, JSGeneratorObject::kContinuationOffset),
                Smi::FromInt(l_continuation.pos()));
        __ movp(FieldOperand(rax, JSGeneratorObject::kContextOffset), rsi);
        __ movp(rcx, rsi);
        __ RecordWriteField(rax, JSGeneratorObject::kContextOffset, rcx, rdx,
                            kDontSaveFPRegs);
        __ CallRuntime(Runtime::kSuspendJSGeneratorObject, 1);
        __ movp(context_register(),
                Operand(rbp, StandardFrameConstants::kContextOffset));
        __ Pop(rax);                                       // result
        EmitReturnSequence();
        __ bind(&l_resume);                                // received in rax
        __ PopTryHandler();
  
        // receiver = iter; f = 'next'; arg = received;
        __ bind(&l_next);
  
        __ LoadRoot(load_name, Heap::knext_stringRootIndex);
        __ Push(load_name);                           // "next"
        __ Push(Operand(rsp, 2 * kPointerSize));      // iter
        __ Push(rax);                                 // received
  
        // result = receiver[f](arg);
        __ bind(&l_call);
        __ movp(load_receiver, Operand(rsp, kPointerSize));
        if (FLAG_vector_ics) {
          __ Move(VectorLoadICDescriptor::SlotRegister(),
                  SmiFromSlot(expr->KeyedLoadFeedbackSlot()));
        }
        Handle<Code> ic = CodeFactory::KeyedLoadIC(isolate()).code();
        CallIC(ic, TypeFeedbackId::None());
        __ movp(rdi, rax);
        __ movp(Operand(rsp, 2 * kPointerSize), rdi);
        CallFunctionStub stub(isolate(), 1, CALL_AS_METHOD);
        __ CallStub(&stub);
  
        __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
        __ Drop(1);  // The function is still on the stack; drop it.
  
        // if (!result.done) goto l_try;
        __ bind(&l_loop);
        __ Move(load_receiver, rax);
        __ Push(load_receiver);                               // save result
        __ LoadRoot(load_name, Heap::kdone_stringRootIndex);  // "done"
        if (FLAG_vector_ics) {
          __ Move(VectorLoadICDescriptor::SlotRegister(),
                  SmiFromSlot(expr->DoneFeedbackSlot()));
        }
        CallLoadIC(NOT_CONTEXTUAL);                           // rax=result.done
        Handle<Code> bool_ic = ToBooleanStub::GetUninitialized(isolate());
        CallIC(bool_ic);
        __ testp(result_register(), result_register());
        __ j(zero, &l_try);
  
        // result.value
        __ Pop(load_receiver);                             // result
        __ LoadRoot(load_name, Heap::kvalue_stringRootIndex);  // "value"
        if (FLAG_vector_ics) {
          __ Move(VectorLoadICDescriptor::SlotRegister(),
                  SmiFromSlot(expr->ValueFeedbackSlot()));
        }
        CallLoadIC(NOT_CONTEXTUAL);                        // result.value in rax
        context()->DropAndPlug(2, rax);                    // drop iter and g
        break;
      }
    }
  }
  
  
  void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
      Expression *value,
      JSGeneratorObject::ResumeMode resume_mode) {
    // The value stays in rax, and is ultimately read by the resumed generator, as
    // if CallRuntime(Runtime::kSuspendJSGeneratorObject) returned it. Or it
    // is read to throw the value when the resumed generator is already closed.
    // rbx will hold the generator object until the activation has been resumed.
    VisitForStackValue(generator);
    VisitForAccumulatorValue(value);
    __ Pop(rbx);
  
    // Check generator state.
    Label wrong_state, closed_state, done;
    STATIC_ASSERT(JSGeneratorObject::kGeneratorExecuting < 0);
    STATIC_ASSERT(JSGeneratorObject::kGeneratorClosed == 0);
    __ SmiCompare(FieldOperand(rbx, JSGeneratorObject::kContinuationOffset),
                  Smi::FromInt(0));
    __ j(equal, &closed_state);
    __ j(less, &wrong_state);
  
    // Load suspended function and context.
    __ movp(rsi, FieldOperand(rbx, JSGeneratorObject::kContextOffset));
    __ movp(rdi, FieldOperand(rbx, JSGeneratorObject::kFunctionOffset));
  
    // Push receiver.
    __ Push(FieldOperand(rbx, JSGeneratorObject::kReceiverOffset));
  
    // Push holes for arguments to generator function.
    __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
    __ LoadSharedFunctionInfoSpecialField(rdx, rdx,
        SharedFunctionInfo::kFormalParameterCountOffset);
    __ LoadRoot(rcx, Heap::kTheHoleValueRootIndex);
    Label push_argument_holes, push_frame;
    __ bind(&push_argument_holes);
    __ subp(rdx, Immediate(1));
    __ j(carry, &push_frame);
    __ Push(rcx);
    __ jmp(&push_argument_holes);
  
    // Enter a new JavaScript frame, and initialize its slots as they were when
    // the generator was suspended.
    Label resume_frame;
    __ bind(&push_frame);
    __ call(&resume_frame);
    __ jmp(&done);
    __ bind(&resume_frame);
    __ pushq(rbp);  // Caller's frame pointer.
    __ movp(rbp, rsp);
    __ Push(rsi);  // Callee's context.
    __ Push(rdi);  // Callee's JS Function.
  
    // Load the operand stack size.
    __ movp(rdx, FieldOperand(rbx, JSGeneratorObject::kOperandStackOffset));
    __ movp(rdx, FieldOperand(rdx, FixedArray::kLengthOffset));
    __ SmiToInteger32(rdx, rdx);
  
    // If we are sending a value and there is no operand stack, we can jump back
    // in directly.
    if (resume_mode == JSGeneratorObject::NEXT) {
      Label slow_resume;
      __ cmpp(rdx, Immediate(0));
      __ j(not_zero, &slow_resume);
      __ movp(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
      __ SmiToInteger64(rcx,
          FieldOperand(rbx, JSGeneratorObject::kContinuationOffset));
      __ addp(rdx, rcx);
      __ Move(FieldOperand(rbx, JSGeneratorObject::kContinuationOffset),
              Smi::FromInt(JSGeneratorObject::kGeneratorExecuting));
      __ jmp(rdx);
      __ bind(&slow_resume);
    }
  
    // Otherwise, we push holes for the operand stack and call the runtime to fix
    // up the stack and the handlers.
    Label push_operand_holes, call_resume;
    __ bind(&push_operand_holes);
    __ subp(rdx, Immediate(1));
    __ j(carry, &call_resume);
    __ Push(rcx);
    __ jmp(&push_operand_holes);
    __ bind(&call_resume);
    __ Push(rbx);
    __ Push(result_register());
    __ Push(Smi::FromInt(resume_mode));
    __ CallRuntime(Runtime::kResumeJSGeneratorObject, 3);
    // Not reached: the runtime call returns elsewhere.
    __ Abort(kGeneratorFailedToResume);
  
    // Reach here when generator is closed.
    __ bind(&closed_state);
    if (resume_mode == JSGeneratorObject::NEXT) {
      // Return completed iterator result when generator is closed.
      __ PushRoot(Heap::kUndefinedValueRootIndex);
      // Pop value from top-of-stack slot; box result into result register.
      EmitCreateIteratorResult(true);
    } else {
      // Throw the provided value.
      __ Push(rax);
      __ CallRuntime(Runtime::kThrow, 1);
    }
    __ jmp(&done);
  
    // Throw error if we attempt to operate on a running generator.
    __ bind(&wrong_state);
    __ Push(rbx);
    __ CallRuntime(Runtime::kThrowGeneratorStateError, 1);
  
    __ bind(&done);
    context()->Plug(result_register());
  }
  
  
  void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
    Label gc_required;
    Label allocated;
  
    Handle<Map> map(isolate()->native_context()->iterator_result_map());
  
    __ Allocate(map->instance_size(), rax, rcx, rdx, &gc_required, TAG_OBJECT);
    __ jmp(&allocated);
  
    __ bind(&gc_required);
    __ Push(Smi::FromInt(map->instance_size()));
    __ CallRuntime(Runtime::kAllocateInNewSpace, 1);
    __ movp(context_register(),
            Operand(rbp, StandardFrameConstants::kContextOffset));
  
    __ bind(&allocated);
    __ Move(rbx, map);
    __ Pop(rcx);
    __ Move(rdx, isolate()->factory()->ToBoolean(done));
    DCHECK_EQ(map->instance_size(), 5 * kPointerSize);
    __ movp(FieldOperand(rax, HeapObject::kMapOffset), rbx);
    __ Move(FieldOperand(rax, JSObject::kPropertiesOffset),
            isolate()->factory()->empty_fixed_array());
    __ Move(FieldOperand(rax, JSObject::kElementsOffset),
            isolate()->factory()->empty_fixed_array());
    __ movp(FieldOperand(rax, JSGeneratorObject::kResultValuePropertyOffset),
            rcx);
    __ movp(FieldOperand(rax, JSGeneratorObject::kResultDonePropertyOffset),
            rdx);
  
    // Only the value field needs a write barrier, as the other values are in the
    // root set.
    __ RecordWriteField(rax, JSGeneratorObject::kResultValuePropertyOffset,
                        rcx, rdx, kDontSaveFPRegs);
  }
  
  
  void FullCodeGenerator::EmitNamedPropertyLoad(Property* prop) {
    SetSourcePosition(prop->position());
    Literal* key = prop->key()->AsLiteral();
    DCHECK(!prop->IsSuperAccess());
  
    __ Move(LoadDescriptor::NameRegister(), key->value());
    if (FLAG_vector_ics) {
      __ Move(VectorLoadICDescriptor::SlotRegister(),
              SmiFromSlot(prop->PropertyFeedbackSlot()));
      CallLoadIC(NOT_CONTEXTUAL);
    } else {
      CallLoadIC(NOT_CONTEXTUAL, prop->PropertyFeedbackId());
    }
  }
  
  
  void FullCodeGenerator::EmitNamedSuperPropertyLoad(Property* prop) {
    // Stack: receiver, home_object
    SetSourcePosition(prop->position());
    Literal* key = prop->key()->AsLiteral();
    DCHECK(!key->value()->IsSmi());
    DCHECK(prop->IsSuperAccess());
  
    __ Push(key->value());
    __ CallRuntime(Runtime::kLoadFromSuper, 3);
  }
  
  
  void FullCodeGenerator::EmitKeyedPropertyLoad(Property* prop) {
    SetSourcePosition(prop->position());
    Handle<Code> ic = CodeFactory::KeyedLoadIC(isolate()).code();
    if (FLAG_vector_ics) {
      __ Move(VectorLoadICDescriptor::SlotRegister(),
              SmiFromSlot(prop->PropertyFeedbackSlot()));
      CallIC(ic);
    } else {
      CallIC(ic, prop->PropertyFeedbackId());
    }
  }
  
  
  void FullCodeGenerator::EmitKeyedSuperPropertyLoad(Property* prop) {
    // Stack: receiver, home_object, key.
    SetSourcePosition(prop->position());
  
    __ CallRuntime(Runtime::kLoadKeyedFromSuper, 3);
  }
  
  
  void FullCodeGenerator::EmitInlineSmiBinaryOp(BinaryOperation* expr,
                                                Token::Value op,
                                                OverwriteMode mode,
                                                Expression* left,
                                                Expression* right) {
    // Do combined smi check of the operands. Left operand is on the
    // stack (popped into rdx). Right operand is in rax but moved into
    // rcx to make the shifts easier.
    Label done, stub_call, smi_case;
    __ Pop(rdx);
    __ movp(rcx, rax);
    __ orp(rax, rdx);
    JumpPatchSite patch_site(masm_);
    patch_site.EmitJumpIfSmi(rax, &smi_case, Label::kNear);
  
    __ bind(&stub_call);
    __ movp(rax, rcx);
    Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), op, mode).code();
    CallIC(code, expr->BinaryOperationFeedbackId());
    patch_site.EmitPatchInfo();
    __ jmp(&done, Label::kNear);
  
    __ bind(&smi_case);
    switch (op) {
      case Token::SAR:
        __ SmiShiftArithmeticRight(rax, rdx, rcx);
        break;
      case Token::SHL:
        __ SmiShiftLeft(rax, rdx, rcx, &stub_call);
        break;
      case Token::SHR:
        __ SmiShiftLogicalRight(rax, rdx, rcx, &stub_call);
        break;
      case Token::ADD:
        __ SmiAdd(rax, rdx, rcx, &stub_call);
        break;
      case Token::SUB:
        __ SmiSub(rax, rdx, rcx, &stub_call);
        break;
      case Token::MUL:
        __ SmiMul(rax, rdx, rcx, &stub_call);
        break;
      case Token::BIT_OR:
        __ SmiOr(rax, rdx, rcx);
        break;
      case Token::BIT_AND:
        __ SmiAnd(rax, rdx, rcx);
        break;
      case Token::BIT_XOR:
        __ SmiXor(rax, rdx, rcx);
        break;
      default:
        UNREACHABLE();
        break;
    }
  
    __ bind(&done);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitBinaryOp(BinaryOperation* expr,
                                       Token::Value op,
                                       OverwriteMode mode) {
    __ Pop(rdx);
    Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), op, mode).code();
    JumpPatchSite patch_site(masm_);    // unbound, signals no inlined smi code.
    CallIC(code, expr->BinaryOperationFeedbackId());
    patch_site.EmitPatchInfo();
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitAssignment(Expression* expr) {
    DCHECK(expr->IsValidReferenceExpression());
  
    Property* prop = expr->AsProperty();
    LhsKind assign_type = GetAssignType(prop);
  
    switch (assign_type) {
      case VARIABLE: {
        Variable* var = expr->AsVariableProxy()->var();
        EffectContext context(this);
        EmitVariableAssignment(var, Token::ASSIGN);
        break;
      }
      case NAMED_PROPERTY: {
        __ Push(rax);  // Preserve value.
        VisitForAccumulatorValue(prop->obj());
        __ Move(StoreDescriptor::ReceiverRegister(), rax);
        __ Pop(StoreDescriptor::ValueRegister());  // Restore value.
        __ Move(StoreDescriptor::NameRegister(),
                prop->key()->AsLiteral()->value());
        CallStoreIC();
        break;
      }
      case NAMED_SUPER_PROPERTY: {
        __ Push(rax);
        VisitForStackValue(prop->obj()->AsSuperReference()->this_var());
        EmitLoadHomeObject(prop->obj()->AsSuperReference());
        // stack: value, this; rax: home_object
        Register scratch = rcx;
        Register scratch2 = rdx;
        __ Move(scratch, result_register());               // home_object
        __ movp(rax, MemOperand(rsp, kPointerSize));       // value
        __ movp(scratch2, MemOperand(rsp, 0));             // this
        __ movp(MemOperand(rsp, kPointerSize), scratch2);  // this
        __ movp(MemOperand(rsp, 0), scratch);              // home_object
        // stack: this, home_object; rax: value
        EmitNamedSuperPropertyStore(prop);
        break;
      }
      case KEYED_SUPER_PROPERTY: {
        __ Push(rax);
        VisitForStackValue(prop->obj()->AsSuperReference()->this_var());
        EmitLoadHomeObject(prop->obj()->AsSuperReference());
        __ Push(result_register());
        VisitForAccumulatorValue(prop->key());
        Register scratch = rcx;
        Register scratch2 = rdx;
        __ movp(scratch2, MemOperand(rsp, 2 * kPointerSize));  // value
        // stack: value, this, home_object; rax: key, rdx: value
        __ movp(scratch, MemOperand(rsp, kPointerSize));  // this
        __ movp(MemOperand(rsp, 2 * kPointerSize), scratch);
        __ movp(scratch, MemOperand(rsp, 0));  // home_object
        __ movp(MemOperand(rsp, kPointerSize), scratch);
        __ movp(MemOperand(rsp, 0), rax);
        __ Move(rax, scratch2);
        // stack: this, home_object, key; rax: value.
        EmitKeyedSuperPropertyStore(prop);
        break;
      }
      case KEYED_PROPERTY: {
        __ Push(rax);  // Preserve value.
        VisitForStackValue(prop->obj());
        VisitForAccumulatorValue(prop->key());
        __ Move(StoreDescriptor::NameRegister(), rax);
        __ Pop(StoreDescriptor::ReceiverRegister());
        __ Pop(StoreDescriptor::ValueRegister());  // Restore value.
        Handle<Code> ic =
            CodeFactory::KeyedStoreIC(isolate(), strict_mode()).code();
        CallIC(ic);
        break;
      }
    }
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitStoreToStackLocalOrContextSlot(
      Variable* var, MemOperand location) {
    __ movp(location, rax);
    if (var->IsContextSlot()) {
      __ movp(rdx, rax);
      __ RecordWriteContextSlot(
          rcx, Context::SlotOffset(var->index()), rdx, rbx, kDontSaveFPRegs);
    }
  }
  
  
  void FullCodeGenerator::EmitVariableAssignment(Variable* var,
                                                 Token::Value op) {
    if (var->IsUnallocated()) {
      // Global var, const, or let.
      __ Move(StoreDescriptor::NameRegister(), var->name());
      __ movp(StoreDescriptor::ReceiverRegister(), GlobalObjectOperand());
      CallStoreIC();
  
    } else if (op == Token::INIT_CONST_LEGACY) {
      // Const initializers need a write barrier.
      DCHECK(!var->IsParameter());  // No const parameters.
      if (var->IsLookupSlot()) {
        __ Push(rax);
        __ Push(rsi);
        __ Push(var->name());
        __ CallRuntime(Runtime::kInitializeLegacyConstLookupSlot, 3);
      } else {
        DCHECK(var->IsStackLocal() || var->IsContextSlot());
        Label skip;
        MemOperand location = VarOperand(var, rcx);
        __ movp(rdx, location);
        __ CompareRoot(rdx, Heap::kTheHoleValueRootIndex);
        __ j(not_equal, &skip);
        EmitStoreToStackLocalOrContextSlot(var, location);
        __ bind(&skip);
      }
  
    } else if (var->mode() == LET && op != Token::INIT_LET) {
      // Non-initializing assignment to let variable needs a write barrier.
      DCHECK(!var->IsLookupSlot());
      DCHECK(var->IsStackAllocated() || var->IsContextSlot());
      Label assign;
      MemOperand location = VarOperand(var, rcx);
      __ movp(rdx, location);
      __ CompareRoot(rdx, Heap::kTheHoleValueRootIndex);
      __ j(not_equal, &assign, Label::kNear);
      __ Push(var->name());
      __ CallRuntime(Runtime::kThrowReferenceError, 1);
      __ bind(&assign);
      EmitStoreToStackLocalOrContextSlot(var, location);
  
    } else if (!var->is_const_mode() || op == Token::INIT_CONST) {
      if (var->IsLookupSlot()) {
        // Assignment to var.
        __ Push(rax);  // Value.
        __ Push(rsi);  // Context.
        __ Push(var->name());
        __ Push(Smi::FromInt(strict_mode()));
        __ CallRuntime(Runtime::kStoreLookupSlot, 4);
      } else {
        // Assignment to var or initializing assignment to let/const in harmony
        // mode.
        DCHECK(var->IsStackAllocated() || var->IsContextSlot());
        MemOperand location = VarOperand(var, rcx);
        if (generate_debug_code_ && op == Token::INIT_LET) {
          // Check for an uninitialized let binding.
          __ movp(rdx, location);
          __ CompareRoot(rdx, Heap::kTheHoleValueRootIndex);
          __ Check(equal, kLetBindingReInitialization);
        }
        EmitStoreToStackLocalOrContextSlot(var, location);
      }
    }
    // Non-initializing assignments to consts are ignored.
  }
  
  
  void FullCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) {
    // Assignment to a property, using a named store IC.
    Property* prop = expr->target()->AsProperty();
    DCHECK(prop != NULL);
    DCHECK(prop->key()->IsLiteral());
  
    // Record source code position before IC call.
    SetSourcePosition(expr->position());
    __ Move(StoreDescriptor::NameRegister(), prop->key()->AsLiteral()->value());
    __ Pop(StoreDescriptor::ReceiverRegister());
    CallStoreIC(expr->AssignmentFeedbackId());
  
    PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitNamedSuperPropertyStore(Property* prop) {
    // Assignment to named property of super.
    // rax : value
    // stack : receiver ('this'), home_object
    DCHECK(prop != NULL);
    Literal* key = prop->key()->AsLiteral();
    DCHECK(key != NULL);
  
    __ Push(key->value());
    __ Push(rax);
    __ CallRuntime((strict_mode() == STRICT ? Runtime::kStoreToSuper_Strict
                                            : Runtime::kStoreToSuper_Sloppy),
                   4);
  }
  
  
  void FullCodeGenerator::EmitKeyedSuperPropertyStore(Property* prop) {
    // Assignment to named property of super.
    // rax : value
    // stack : receiver ('this'), home_object, key
    DCHECK(prop != NULL);
  
    __ Push(rax);
    __ CallRuntime((strict_mode() == STRICT ? Runtime::kStoreKeyedToSuper_Strict
                                            : Runtime::kStoreKeyedToSuper_Sloppy),
                   4);
  }
  
  
  void FullCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) {
    // Assignment to a property, using a keyed store IC.
  
    __ Pop(StoreDescriptor::NameRegister());  // Key.
    __ Pop(StoreDescriptor::ReceiverRegister());
    DCHECK(StoreDescriptor::ValueRegister().is(rax));
    // Record source code position before IC call.
    SetSourcePosition(expr->position());
    Handle<Code> ic = CodeFactory::KeyedStoreIC(isolate(), strict_mode()).code();
    CallIC(ic, expr->AssignmentFeedbackId());
  
    PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::VisitProperty(Property* expr) {
    Comment cmnt(masm_, "[ Property");
    Expression* key = expr->key();
  
    if (key->IsPropertyName()) {
      if (!expr->IsSuperAccess()) {
        VisitForAccumulatorValue(expr->obj());
        DCHECK(!rax.is(LoadDescriptor::ReceiverRegister()));
        __ movp(LoadDescriptor::ReceiverRegister(), rax);
        EmitNamedPropertyLoad(expr);
      } else {
        VisitForStackValue(expr->obj()->AsSuperReference()->this_var());
        EmitLoadHomeObject(expr->obj()->AsSuperReference());
        __ Push(result_register());
        EmitNamedSuperPropertyLoad(expr);
      }
      PrepareForBailoutForId(expr->LoadId(), TOS_REG);
      context()->Plug(rax);
    } else {
      if (!expr->IsSuperAccess()) {
        VisitForStackValue(expr->obj());
        VisitForAccumulatorValue(expr->key());
        __ Move(LoadDescriptor::NameRegister(), rax);
        __ Pop(LoadDescriptor::ReceiverRegister());
        EmitKeyedPropertyLoad(expr);
      } else {
        VisitForStackValue(expr->obj()->AsSuperReference()->this_var());
        EmitLoadHomeObject(expr->obj()->AsSuperReference());
        __ Push(result_register());
        VisitForStackValue(expr->key());
        EmitKeyedSuperPropertyLoad(expr);
      }
      context()->Plug(rax);
    }
  }
  
  
  void FullCodeGenerator::CallIC(Handle<Code> code,
                                 TypeFeedbackId ast_id) {
    ic_total_count_++;
    __ call(code, RelocInfo::CODE_TARGET, ast_id);
  }
  
  
  // Code common for calls using the IC.
  void FullCodeGenerator::EmitCallWithLoadIC(Call* expr) {
    Expression* callee = expr->expression();
  
    CallICState::CallType call_type =
        callee->IsVariableProxy() ? CallICState::FUNCTION : CallICState::METHOD;
    // Get the target function.
    if (call_type == CallICState::FUNCTION) {
      { StackValueContext context(this);
        EmitVariableLoad(callee->AsVariableProxy());
        PrepareForBailout(callee, NO_REGISTERS);
      }
      // Push undefined as receiver. This is patched in the method prologue if it
      // is a sloppy mode method.
      __ Push(isolate()->factory()->undefined_value());
    } else {
      // Load the function from the receiver.
      DCHECK(callee->IsProperty());
      DCHECK(!callee->AsProperty()->IsSuperAccess());
      __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, 0));
      EmitNamedPropertyLoad(callee->AsProperty());
      PrepareForBailoutForId(callee->AsProperty()->LoadId(), TOS_REG);
      // Push the target function under the receiver.
      __ Push(Operand(rsp, 0));
      __ movp(Operand(rsp, kPointerSize), rax);
    }
  
    EmitCall(expr, call_type);
  }
  
  
  void FullCodeGenerator::EmitSuperCallWithLoadIC(Call* expr) {
    Expression* callee = expr->expression();
    DCHECK(callee->IsProperty());
    Property* prop = callee->AsProperty();
    DCHECK(prop->IsSuperAccess());
  
    SetSourcePosition(prop->position());
    Literal* key = prop->key()->AsLiteral();
    DCHECK(!key->value()->IsSmi());
    // Load the function from the receiver.
    SuperReference* super_ref = prop->obj()->AsSuperReference();
    EmitLoadHomeObject(super_ref);
    __ Push(rax);
    VisitForAccumulatorValue(super_ref->this_var());
    __ Push(rax);
    __ Push(rax);
    __ Push(Operand(rsp, kPointerSize * 2));
    __ Push(key->value());
  
    // Stack here:
    //  - home_object
    //  - this (receiver)
    //  - this (receiver) <-- LoadFromSuper will pop here and below.
    //  - home_object
    //  - key
    __ CallRuntime(Runtime::kLoadFromSuper, 3);
  
    // Replace home_object with target function.
    __ movp(Operand(rsp, kPointerSize), rax);
  
    // Stack here:
    // - target function
    // - this (receiver)
    EmitCall(expr, CallICState::METHOD);
  }
  
  
  // Common code for calls using the IC.
  void FullCodeGenerator::EmitKeyedCallWithLoadIC(Call* expr,
                                                  Expression* key) {
    // Load the key.
    VisitForAccumulatorValue(key);
  
    Expression* callee = expr->expression();
  
    // Load the function from the receiver.
    DCHECK(callee->IsProperty());
    __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, 0));
    __ Move(LoadDescriptor::NameRegister(), rax);
    EmitKeyedPropertyLoad(callee->AsProperty());
    PrepareForBailoutForId(callee->AsProperty()->LoadId(), TOS_REG);
  
    // Push the target function under the receiver.
    __ Push(Operand(rsp, 0));
    __ movp(Operand(rsp, kPointerSize), rax);
  
    EmitCall(expr, CallICState::METHOD);
  }
  
  
  void FullCodeGenerator::EmitKeyedSuperCallWithLoadIC(Call* expr) {
    Expression* callee = expr->expression();
    DCHECK(callee->IsProperty());
    Property* prop = callee->AsProperty();
    DCHECK(prop->IsSuperAccess());
  
    SetSourcePosition(prop->position());
    // Load the function from the receiver.
    SuperReference* super_ref = prop->obj()->AsSuperReference();
    EmitLoadHomeObject(super_ref);
    __ Push(rax);
    VisitForAccumulatorValue(super_ref->this_var());
    __ Push(rax);
    __ Push(rax);
    __ Push(Operand(rsp, kPointerSize * 2));
    VisitForStackValue(prop->key());
  
    // Stack here:
    //  - home_object
    //  - this (receiver)
    //  - this (receiver) <-- LoadKeyedFromSuper will pop here and below.
    //  - home_object
    //  - key
    __ CallRuntime(Runtime::kLoadKeyedFromSuper, 3);
  
    // Replace home_object with target function.
    __ movp(Operand(rsp, kPointerSize), rax);
  
    // Stack here:
    // - target function
    // - this (receiver)
    EmitCall(expr, CallICState::METHOD);
  }
  
  
  void FullCodeGenerator::EmitCall(Call* expr, CallICState::CallType call_type) {
    // Load the arguments.
    ZoneList<Expression*>* args = expr->arguments();
    int arg_count = args->length();
    { PreservePositionScope scope(masm()->positions_recorder());
      for (int i = 0; i < arg_count; i++) {
        VisitForStackValue(args->at(i));
      }
    }
  
    // Record source position of the IC call.
    SetSourcePosition(expr->position());
    Handle<Code> ic = CallIC::initialize_stub(
        isolate(), arg_count, call_type);
    __ Move(rdx, SmiFromSlot(expr->CallFeedbackSlot()));
    __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
    // Don't assign a type feedback id to the IC, since type feedback is provided
    // by the vector above.
    CallIC(ic);
  
    RecordJSReturnSite(expr);
  
    // Restore context register.
    __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
    // Discard the function left on TOS.
    context()->DropAndPlug(1, rax);
  }
  
  
  void FullCodeGenerator::EmitResolvePossiblyDirectEval(int arg_count) {
    // Push copy of the first argument or undefined if it doesn't exist.
    if (arg_count > 0) {
      __ Push(Operand(rsp, arg_count * kPointerSize));
    } else {
      __ PushRoot(Heap::kUndefinedValueRootIndex);
    }
  
    // Push the receiver of the enclosing function and do runtime call.
    StackArgumentsAccessor args(rbp, info_->scope()->num_parameters());
    __ Push(args.GetReceiverOperand());
  
    // Push the language mode.
    __ Push(Smi::FromInt(strict_mode()));
  
    // Push the start position of the scope the calls resides in.
    __ Push(Smi::FromInt(scope()->start_position()));
  
    // Do the runtime call.
    __ CallRuntime(Runtime::kResolvePossiblyDirectEval, 5);
  }
  
  
  void FullCodeGenerator::VisitCall(Call* expr) {
  #ifdef DEBUG
    // We want to verify that RecordJSReturnSite gets called on all paths
    // through this function.  Avoid early returns.
    expr->return_is_recorded_ = false;
  #endif
  
    Comment cmnt(masm_, "[ Call");
    Expression* callee = expr->expression();
    Call::CallType call_type = expr->GetCallType(isolate());
  
    if (call_type == Call::POSSIBLY_EVAL_CALL) {
      // In a call to eval, we first call RuntimeHidden_ResolvePossiblyDirectEval
      // to resolve the function we need to call and the receiver of the call.
      // Then we call the resolved function using the given arguments.
      ZoneList<Expression*>* args = expr->arguments();
      int arg_count = args->length();
      { PreservePositionScope pos_scope(masm()->positions_recorder());
        VisitForStackValue(callee);
        __ PushRoot(Heap::kUndefinedValueRootIndex);  // Reserved receiver slot.
  
        // Push the arguments.
        for (int i = 0; i < arg_count; i++) {
          VisitForStackValue(args->at(i));
        }
  
        // Push a copy of the function (found below the arguments) and resolve
        // eval.
        __ Push(Operand(rsp, (arg_count + 1) * kPointerSize));
        EmitResolvePossiblyDirectEval(arg_count);
  
        // The runtime call returns a pair of values in rax (function) and
        // rdx (receiver). Touch up the stack with the right values.
        __ movp(Operand(rsp, (arg_count + 0) * kPointerSize), rdx);
        __ movp(Operand(rsp, (arg_count + 1) * kPointerSize), rax);
  
        PrepareForBailoutForId(expr->EvalOrLookupId(), NO_REGISTERS);
      }
      // Record source position for debugger.
      SetSourcePosition(expr->position());
      CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
      __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
      __ CallStub(&stub);
      RecordJSReturnSite(expr);
      // Restore context register.
      __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
      context()->DropAndPlug(1, rax);
    } else if (call_type == Call::GLOBAL_CALL) {
      EmitCallWithLoadIC(expr);
  
    } else if (call_type == Call::LOOKUP_SLOT_CALL) {
      // Call to a lookup slot (dynamically introduced variable).
      VariableProxy* proxy = callee->AsVariableProxy();
      Label slow, done;
  
      { PreservePositionScope scope(masm()->positions_recorder());
        // Generate code for loading from variables potentially shadowed by
        // eval-introduced variables.
        EmitDynamicLookupFastCase(proxy, NOT_INSIDE_TYPEOF, &slow, &done);
      }
      __ bind(&slow);
      // Call the runtime to find the function to call (returned in rax) and
      // the object holding it (returned in rdx).
      __ Push(context_register());
      __ Push(proxy->name());
      __ CallRuntime(Runtime::kLoadLookupSlot, 2);
      __ Push(rax);  // Function.
      __ Push(rdx);  // Receiver.
      PrepareForBailoutForId(expr->EvalOrLookupId(), NO_REGISTERS);
  
      // If fast case code has been generated, emit code to push the function
      // and receiver and have the slow path jump around this code.
      if (done.is_linked()) {
        Label call;
        __ jmp(&call, Label::kNear);
        __ bind(&done);
        // Push function.
        __ Push(rax);
        // The receiver is implicitly the global receiver. Indicate this by
        // passing the hole to the call function stub.
        __ PushRoot(Heap::kUndefinedValueRootIndex);
        __ bind(&call);
      }
  
      // The receiver is either the global receiver or an object found by
      // LoadContextSlot.
      EmitCall(expr);
    } else if (call_type == Call::PROPERTY_CALL) {
      Property* property = callee->AsProperty();
      bool is_named_call = property->key()->IsPropertyName();
      if (property->IsSuperAccess()) {
        if (is_named_call) {
          EmitSuperCallWithLoadIC(expr);
        } else {
          EmitKeyedSuperCallWithLoadIC(expr);
        }
      } else {
        {
          PreservePositionScope scope(masm()->positions_recorder());
          VisitForStackValue(property->obj());
        }
        if (is_named_call) {
          EmitCallWithLoadIC(expr);
        } else {
          EmitKeyedCallWithLoadIC(expr, property->key());
        }
      }
    } else {
      DCHECK(call_type == Call::OTHER_CALL);
      // Call to an arbitrary expression not handled specially above.
      { PreservePositionScope scope(masm()->positions_recorder());
        VisitForStackValue(callee);
      }
      __ PushRoot(Heap::kUndefinedValueRootIndex);
      // Emit function call.
      EmitCall(expr);
    }
  
  #ifdef DEBUG
    // RecordJSReturnSite should have been called.
    DCHECK(expr->return_is_recorded_);
  #endif
  }
  
  
  void FullCodeGenerator::VisitCallNew(CallNew* expr) {
    Comment cmnt(masm_, "[ CallNew");
    // According to ECMA-262, section 11.2.2, page 44, the function
    // expression in new calls must be evaluated before the
    // arguments.
  
    // Push constructor on the stack.  If it's not a function it's used as
    // receiver for CALL_NON_FUNCTION, otherwise the value on the stack is
    // ignored.
    VisitForStackValue(expr->expression());
  
    // Push the arguments ("left-to-right") on the stack.
    ZoneList<Expression*>* args = expr->arguments();
    int arg_count = args->length();
    for (int i = 0; i < arg_count; i++) {
      VisitForStackValue(args->at(i));
    }
  
    // Call the construct call builtin that handles allocation and
    // constructor invocation.
    SetSourcePosition(expr->position());
  
    // Load function and argument count into rdi and rax.
    __ Set(rax, arg_count);
    __ movp(rdi, Operand(rsp, arg_count * kPointerSize));
  
    // Record call targets in unoptimized code, but not in the snapshot.
    if (FLAG_pretenuring_call_new) {
      EnsureSlotContainsAllocationSite(expr->AllocationSiteFeedbackSlot());
      DCHECK(expr->AllocationSiteFeedbackSlot().ToInt() ==
             expr->CallNewFeedbackSlot().ToInt() + 1);
    }
  
    __ Move(rbx, FeedbackVector());
    __ Move(rdx, SmiFromSlot(expr->CallNewFeedbackSlot()));
  
    CallConstructStub stub(isolate(), RECORD_CONSTRUCTOR_TARGET);
    __ Call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
    PrepareForBailoutForId(expr->ReturnId(), TOS_REG);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitIsSmi(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    __ JumpIfSmi(rax, if_true);
    __ jmp(if_false);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsNonNegativeSmi(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Condition non_negative_smi = masm()->CheckNonNegativeSmi(rax);
    Split(non_negative_smi, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsObject(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ JumpIfSmi(rax, if_false);
    __ CompareRoot(rax, Heap::kNullValueRootIndex);
    __ j(equal, if_true);
    __ movp(rbx, FieldOperand(rax, HeapObject::kMapOffset));
    // Undetectable objects behave like undefined when tested with typeof.
    __ testb(FieldOperand(rbx, Map::kBitFieldOffset),
             Immediate(1 << Map::kIsUndetectable));
    __ j(not_zero, if_false);
    __ movzxbp(rbx, FieldOperand(rbx, Map::kInstanceTypeOffset));
    __ cmpp(rbx, Immediate(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
    __ j(below, if_false);
    __ cmpp(rbx, Immediate(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(below_equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsSpecObject(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ JumpIfSmi(rax, if_false);
    __ CmpObjectType(rax, FIRST_SPEC_OBJECT_TYPE, rbx);
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(above_equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsUndetectableObject(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ JumpIfSmi(rax, if_false);
    __ movp(rbx, FieldOperand(rax, HeapObject::kMapOffset));
    __ testb(FieldOperand(rbx, Map::kBitFieldOffset),
             Immediate(1 << Map::kIsUndetectable));
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(not_zero, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsStringWrapperSafeForDefaultValueOf(
      CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false, skip_lookup;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ AssertNotSmi(rax);
  
    // Check whether this map has already been checked to be safe for default
    // valueOf.
    __ movp(rbx, FieldOperand(rax, HeapObject::kMapOffset));
    __ testb(FieldOperand(rbx, Map::kBitField2Offset),
             Immediate(1 << Map::kStringWrapperSafeForDefaultValueOf));
    __ j(not_zero, &skip_lookup);
  
    // Check for fast case object. Generate false result for slow case object.
    __ movp(rcx, FieldOperand(rax, JSObject::kPropertiesOffset));
    __ movp(rcx, FieldOperand(rcx, HeapObject::kMapOffset));
    __ CompareRoot(rcx, Heap::kHashTableMapRootIndex);
    __ j(equal, if_false);
  
    // Look for valueOf string in the descriptor array, and indicate false if
    // found. Since we omit an enumeration index check, if it is added via a
    // transition that shares its descriptor array, this is a false positive.
    Label entry, loop, done;
  
    // Skip loop if no descriptors are valid.
    __ NumberOfOwnDescriptors(rcx, rbx);
    __ cmpp(rcx, Immediate(0));
    __ j(equal, &done);
  
    __ LoadInstanceDescriptors(rbx, r8);
    // rbx: descriptor array.
    // rcx: valid entries in the descriptor array.
    // Calculate the end of the descriptor array.
    __ imulp(rcx, rcx, Immediate(DescriptorArray::kDescriptorSize));
    __ leap(rcx,
            Operand(r8, rcx, times_pointer_size, DescriptorArray::kFirstOffset));
    // Calculate location of the first key name.
    __ addp(r8, Immediate(DescriptorArray::kFirstOffset));
    // Loop through all the keys in the descriptor array. If one of these is the
    // internalized string "valueOf" the result is false.
    __ jmp(&entry);
    __ bind(&loop);
    __ movp(rdx, FieldOperand(r8, 0));
    __ Cmp(rdx, isolate()->factory()->value_of_string());
    __ j(equal, if_false);
    __ addp(r8, Immediate(DescriptorArray::kDescriptorSize * kPointerSize));
    __ bind(&entry);
    __ cmpp(r8, rcx);
    __ j(not_equal, &loop);
  
    __ bind(&done);
  
    // Set the bit in the map to indicate that there is no local valueOf field.
    __ orp(FieldOperand(rbx, Map::kBitField2Offset),
           Immediate(1 << Map::kStringWrapperSafeForDefaultValueOf));
  
    __ bind(&skip_lookup);
  
    // If a valueOf property is not found on the object check that its
    // prototype is the un-modified String prototype. If not result is false.
    __ movp(rcx, FieldOperand(rbx, Map::kPrototypeOffset));
    __ testp(rcx, Immediate(kSmiTagMask));
    __ j(zero, if_false);
    __ movp(rcx, FieldOperand(rcx, HeapObject::kMapOffset));
    __ movp(rdx, Operand(rsi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
    __ movp(rdx, FieldOperand(rdx, GlobalObject::kNativeContextOffset));
    __ cmpp(rcx,
            ContextOperand(rdx, Context::STRING_FUNCTION_PROTOTYPE_MAP_INDEX));
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsFunction(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ JumpIfSmi(rax, if_false);
    __ CmpObjectType(rax, JS_FUNCTION_TYPE, rbx);
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
    __ CheckMap(rax, map, if_false, DO_SMI_CHECK);
    __ cmpl(FieldOperand(rax, HeapNumber::kExponentOffset),
            Immediate(0x1));
    __ j(no_overflow, if_false);
    __ cmpl(FieldOperand(rax, HeapNumber::kMantissaOffset),
            Immediate(0x00000000));
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ JumpIfSmi(rax, if_false);
    __ CmpObjectType(rax, JS_ARRAY_TYPE, rbx);
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitIsRegExp(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ JumpIfSmi(rax, if_false);
    __ CmpObjectType(rax, JS_REGEXP_TYPE, rbx);
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  
  void FullCodeGenerator::EmitIsConstructCall(CallRuntime* expr) {
    DCHECK(expr->arguments()->length() == 0);
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    // Get the frame pointer for the calling frame.
    __ movp(rax, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
  
    // Skip the arguments adaptor frame if it exists.
    Label check_frame_marker;
    __ Cmp(Operand(rax, StandardFrameConstants::kContextOffset),
           Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
    __ j(not_equal, &check_frame_marker);
    __ movp(rax, Operand(rax, StandardFrameConstants::kCallerFPOffset));
  
    // Check the marker in the calling frame.
    __ bind(&check_frame_marker);
    __ Cmp(Operand(rax, StandardFrameConstants::kMarkerOffset),
           Smi::FromInt(StackFrame::CONSTRUCT));
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitObjectEquals(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 2);
  
    // Load the two objects into registers and perform the comparison.
    VisitForStackValue(args->at(0));
    VisitForAccumulatorValue(args->at(1));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ Pop(rbx);
    __ cmpp(rax, rbx);
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    Split(equal, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitArguments(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    // ArgumentsAccessStub expects the key in rdx and the formal
    // parameter count in rax.
    VisitForAccumulatorValue(args->at(0));
    __ movp(rdx, rax);
    __ Move(rax, Smi::FromInt(info_->scope()->num_parameters()));
    ArgumentsAccessStub stub(isolate(), ArgumentsAccessStub::READ_ELEMENT);
    __ CallStub(&stub);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitArgumentsLength(CallRuntime* expr) {
    DCHECK(expr->arguments()->length() == 0);
  
    Label exit;
    // Get the number of formal parameters.
    __ Move(rax, Smi::FromInt(info_->scope()->num_parameters()));
  
    // Check if the calling frame is an arguments adaptor frame.
    __ movp(rbx, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
    __ Cmp(Operand(rbx, StandardFrameConstants::kContextOffset),
           Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
    __ j(not_equal, &exit, Label::kNear);
  
    // Arguments adaptor case: Read the arguments length from the
    // adaptor frame.
    __ movp(rax, Operand(rbx, ArgumentsAdaptorFrameConstants::kLengthOffset));
  
    __ bind(&exit);
    __ AssertSmi(rax);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitClassOf(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
    Label done, null, function, non_function_constructor;
  
    VisitForAccumulatorValue(args->at(0));
  
    // If the object is a smi, we return null.
    __ JumpIfSmi(rax, &null);
  
    // Check that the object is a JS object but take special care of JS
    // functions to make sure they have 'Function' as their class.
    // Assume that there are only two callable types, and one of them is at
    // either end of the type range for JS object types. Saves extra comparisons.
    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
    __ CmpObjectType(rax, FIRST_SPEC_OBJECT_TYPE, rax);
    // Map is now in rax.
    __ j(below, &null);
    STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                  FIRST_SPEC_OBJECT_TYPE + 1);
    __ j(equal, &function);
  
    __ CmpInstanceType(rax, LAST_SPEC_OBJECT_TYPE);
    STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                  LAST_SPEC_OBJECT_TYPE - 1);
    __ j(equal, &function);
    // Assume that there is no larger type.
    STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE == LAST_TYPE - 1);
  
    // Check if the constructor in the map is a JS function.
    __ movp(rax, FieldOperand(rax, Map::kConstructorOffset));
    __ CmpObjectType(rax, JS_FUNCTION_TYPE, rbx);
    __ j(not_equal, &non_function_constructor);
  
    // rax now contains the constructor function. Grab the
    // instance class name from there.
    __ movp(rax, FieldOperand(rax, JSFunction::kSharedFunctionInfoOffset));
    __ movp(rax, FieldOperand(rax, SharedFunctionInfo::kInstanceClassNameOffset));
    __ jmp(&done);
  
    // Functions have class 'Function'.
    __ bind(&function);
    __ Move(rax, isolate()->factory()->Function_string());
    __ jmp(&done);
  
    // Objects with a non-function constructor have class 'Object'.
    __ bind(&non_function_constructor);
    __ Move(rax, isolate()->factory()->Object_string());
    __ jmp(&done);
  
    // Non-JS objects have class null.
    __ bind(&null);
    __ LoadRoot(rax, Heap::kNullValueRootIndex);
  
    // All done.
    __ bind(&done);
  
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitSubString(CallRuntime* expr) {
    // Load the arguments on the stack and call the stub.
    SubStringStub stub(isolate());
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 3);
    VisitForStackValue(args->at(0));
    VisitForStackValue(args->at(1));
    VisitForStackValue(args->at(2));
    __ CallStub(&stub);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitRegExpExec(CallRuntime* expr) {
    // Load the arguments on the stack and call the stub.
    RegExpExecStub stub(isolate());
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 4);
    VisitForStackValue(args->at(0));
    VisitForStackValue(args->at(1));
    VisitForStackValue(args->at(2));
    VisitForStackValue(args->at(3));
    __ CallStub(&stub);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitValueOf(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));  // Load the object.
  
    Label done;
    // If the object is a smi return the object.
    __ JumpIfSmi(rax, &done);
    // If the object is not a value type, return the object.
    __ CmpObjectType(rax, JS_VALUE_TYPE, rbx);
    __ j(not_equal, &done);
    __ movp(rax, FieldOperand(rax, JSValue::kValueOffset));
  
    __ bind(&done);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitDateField(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 2);
    DCHECK_NE(NULL, args->at(1)->AsLiteral());
    Smi* index = Smi::cast(*(args->at(1)->AsLiteral()->value()));
  
    VisitForAccumulatorValue(args->at(0));  // Load the object.
  
    Label runtime, done, not_date_object;
    Register object = rax;
    Register result = rax;
    Register scratch = rcx;
  
    __ JumpIfSmi(object, &not_date_object);
    __ CmpObjectType(object, JS_DATE_TYPE, scratch);
    __ j(not_equal, &not_date_object);
  
    if (index->value() == 0) {
      __ movp(result, FieldOperand(object, JSDate::kValueOffset));
      __ jmp(&done);
    } else {
      if (index->value() < JSDate::kFirstUncachedField) {
        ExternalReference stamp = ExternalReference::date_cache_stamp(isolate());
        Operand stamp_operand = __ ExternalOperand(stamp);
        __ movp(scratch, stamp_operand);
        __ cmpp(scratch, FieldOperand(object, JSDate::kCacheStampOffset));
        __ j(not_equal, &runtime, Label::kNear);
        __ movp(result, FieldOperand(object, JSDate::kValueOffset +
                                             kPointerSize * index->value()));
        __ jmp(&done);
      }
      __ bind(&runtime);
      __ PrepareCallCFunction(2);
      __ movp(arg_reg_1, object);
      __ Move(arg_reg_2, index, Assembler::RelocInfoNone());
      __ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2);
      __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
      __ jmp(&done);
    }
  
    __ bind(&not_date_object);
    __ CallRuntime(Runtime::kThrowNotDateError, 0);
    __ bind(&done);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitOneByteSeqStringSetChar(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK_EQ(3, args->length());
  
    Register string = rax;
    Register index = rbx;
    Register value = rcx;
  
    VisitForStackValue(args->at(0));        // index
    VisitForStackValue(args->at(1));        // value
    VisitForAccumulatorValue(args->at(2));  // string
    __ Pop(value);
    __ Pop(index);
  
    if (FLAG_debug_code) {
      __ Check(__ CheckSmi(value), kNonSmiValue);
      __ Check(__ CheckSmi(index), kNonSmiValue);
    }
  
    __ SmiToInteger32(value, value);
    __ SmiToInteger32(index, index);
  
    if (FLAG_debug_code) {
      static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
      __ EmitSeqStringSetCharCheck(string, index, value, one_byte_seq_type);
    }
  
    __ movb(FieldOperand(string, index, times_1, SeqOneByteString::kHeaderSize),
            value);
    context()->Plug(string);
  }
  
  
  void FullCodeGenerator::EmitTwoByteSeqStringSetChar(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK_EQ(3, args->length());
  
    Register string = rax;
    Register index = rbx;
    Register value = rcx;
  
    VisitForStackValue(args->at(0));        // index
    VisitForStackValue(args->at(1));        // value
    VisitForAccumulatorValue(args->at(2));  // string
    __ Pop(value);
    __ Pop(index);
  
    if (FLAG_debug_code) {
      __ Check(__ CheckSmi(value), kNonSmiValue);
      __ Check(__ CheckSmi(index), kNonSmiValue);
    }
  
    __ SmiToInteger32(value, value);
    __ SmiToInteger32(index, index);
  
    if (FLAG_debug_code) {
      static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
      __ EmitSeqStringSetCharCheck(string, index, value, two_byte_seq_type);
    }
  
    __ movw(FieldOperand(string, index, times_2, SeqTwoByteString::kHeaderSize),
            value);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitMathPow(CallRuntime* expr) {
    // Load the arguments on the stack and call the runtime function.
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 2);
    VisitForStackValue(args->at(0));
    VisitForStackValue(args->at(1));
    MathPowStub stub(isolate(), MathPowStub::ON_STACK);
    __ CallStub(&stub);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitSetValueOf(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 2);
  
    VisitForStackValue(args->at(0));  // Load the object.
    VisitForAccumulatorValue(args->at(1));  // Load the value.
    __ Pop(rbx);  // rax = value. rbx = object.
  
    Label done;
    // If the object is a smi, return the value.
    __ JumpIfSmi(rbx, &done);
  
    // If the object is not a value type, return the value.
    __ CmpObjectType(rbx, JS_VALUE_TYPE, rcx);
    __ j(not_equal, &done);
  
    // Store the value.
    __ movp(FieldOperand(rbx, JSValue::kValueOffset), rax);
    // Update the write barrier.  Save the value as it will be
    // overwritten by the write barrier code and is needed afterward.
    __ movp(rdx, rax);
    __ RecordWriteField(rbx, JSValue::kValueOffset, rdx, rcx, kDontSaveFPRegs);
  
    __ bind(&done);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitNumberToString(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK_EQ(args->length(), 1);
  
    // Load the argument into rax and call the stub.
    VisitForAccumulatorValue(args->at(0));
  
    NumberToStringStub stub(isolate());
    __ CallStub(&stub);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitStringCharFromCode(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label done;
    StringCharFromCodeGenerator generator(rax, rbx);
    generator.GenerateFast(masm_);
    __ jmp(&done);
  
    NopRuntimeCallHelper call_helper;
    generator.GenerateSlow(masm_, call_helper);
  
    __ bind(&done);
    context()->Plug(rbx);
  }
  
  
  void FullCodeGenerator::EmitStringCharCodeAt(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 2);
  
    VisitForStackValue(args->at(0));
    VisitForAccumulatorValue(args->at(1));
  
    Register object = rbx;
    Register index = rax;
    Register result = rdx;
  
    __ Pop(object);
  
    Label need_conversion;
    Label index_out_of_range;
    Label done;
    StringCharCodeAtGenerator generator(object,
                                        index,
                                        result,
                                        &need_conversion,
                                        &need_conversion,
                                        &index_out_of_range,
                                        STRING_INDEX_IS_NUMBER);
    generator.GenerateFast(masm_);
    __ jmp(&done);
  
    __ bind(&index_out_of_range);
    // When the index is out of range, the spec requires us to return
    // NaN.
    __ LoadRoot(result, Heap::kNanValueRootIndex);
    __ jmp(&done);
  
    __ bind(&need_conversion);
    // Move the undefined value into the result register, which will
    // trigger conversion.
    __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
    __ jmp(&done);
  
    NopRuntimeCallHelper call_helper;
    generator.GenerateSlow(masm_, call_helper);
  
    __ bind(&done);
    context()->Plug(result);
  }
  
  
  void FullCodeGenerator::EmitStringCharAt(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 2);
  
    VisitForStackValue(args->at(0));
    VisitForAccumulatorValue(args->at(1));
  
    Register object = rbx;
    Register index = rax;
    Register scratch = rdx;
    Register result = rax;
  
    __ Pop(object);
  
    Label need_conversion;
    Label index_out_of_range;
    Label done;
    StringCharAtGenerator generator(object,
                                    index,
                                    scratch,
                                    result,
                                    &need_conversion,
                                    &need_conversion,
                                    &index_out_of_range,
                                    STRING_INDEX_IS_NUMBER);
    generator.GenerateFast(masm_);
    __ jmp(&done);
  
    __ bind(&index_out_of_range);
    // When the index is out of range, the spec requires us to return
    // the empty string.
    __ LoadRoot(result, Heap::kempty_stringRootIndex);
    __ jmp(&done);
  
    __ bind(&need_conversion);
    // Move smi zero into the result register, which will trigger
    // conversion.
    __ Move(result, Smi::FromInt(0));
    __ jmp(&done);
  
    NopRuntimeCallHelper call_helper;
    generator.GenerateSlow(masm_, call_helper);
  
    __ bind(&done);
    context()->Plug(result);
  }
  
  
  void FullCodeGenerator::EmitStringAdd(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK_EQ(2, args->length());
    VisitForStackValue(args->at(0));
    VisitForAccumulatorValue(args->at(1));
  
    __ Pop(rdx);
    StringAddStub stub(isolate(), STRING_ADD_CHECK_BOTH, NOT_TENURED);
    __ CallStub(&stub);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitStringCompare(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK_EQ(2, args->length());
  
    VisitForStackValue(args->at(0));
    VisitForStackValue(args->at(1));
  
    StringCompareStub stub(isolate());
    __ CallStub(&stub);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitCallFunction(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() >= 2);
  
    int arg_count = args->length() - 2;  // 2 ~ receiver and function.
    for (int i = 0; i < arg_count + 1; i++) {
      VisitForStackValue(args->at(i));
    }
    VisitForAccumulatorValue(args->last());  // Function.
  
    Label runtime, done;
    // Check for non-function argument (including proxy).
    __ JumpIfSmi(rax, &runtime);
    __ CmpObjectType(rax, JS_FUNCTION_TYPE, rbx);
    __ j(not_equal, &runtime);
  
    // InvokeFunction requires the function in rdi. Move it in there.
    __ movp(rdi, result_register());
    ParameterCount count(arg_count);
    __ InvokeFunction(rdi, count, CALL_FUNCTION, NullCallWrapper());
    __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
    __ jmp(&done);
  
    __ bind(&runtime);
    __ Push(rax);
    __ CallRuntime(Runtime::kCall, args->length());
    __ bind(&done);
  
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitRegExpConstructResult(CallRuntime* expr) {
    RegExpConstructResultStub stub(isolate());
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 3);
    VisitForStackValue(args->at(0));
    VisitForStackValue(args->at(1));
    VisitForAccumulatorValue(args->at(2));
    __ Pop(rbx);
    __ Pop(rcx);
    __ CallStub(&stub);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitGetFromCache(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK_EQ(2, args->length());
  
    DCHECK_NE(NULL, args->at(0)->AsLiteral());
    int cache_id = Smi::cast(*(args->at(0)->AsLiteral()->value()))->value();
  
    Handle<FixedArray> jsfunction_result_caches(
        isolate()->native_context()->jsfunction_result_caches());
    if (jsfunction_result_caches->length() <= cache_id) {
      __ Abort(kAttemptToUseUndefinedCache);
      __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
      context()->Plug(rax);
      return;
    }
  
    VisitForAccumulatorValue(args->at(1));
  
    Register key = rax;
    Register cache = rbx;
    Register tmp = rcx;
    __ movp(cache, ContextOperand(rsi, Context::GLOBAL_OBJECT_INDEX));
    __ movp(cache,
            FieldOperand(cache, GlobalObject::kNativeContextOffset));
    __ movp(cache,
            ContextOperand(cache, Context::JSFUNCTION_RESULT_CACHES_INDEX));
    __ movp(cache,
            FieldOperand(cache, FixedArray::OffsetOfElementAt(cache_id)));
  
    Label done, not_found;
    STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize == 1);
    __ movp(tmp, FieldOperand(cache, JSFunctionResultCache::kFingerOffset));
    // tmp now holds finger offset as a smi.
    SmiIndex index =
        __ SmiToIndex(kScratchRegister, tmp, kPointerSizeLog2);
    __ cmpp(key, FieldOperand(cache,
                              index.reg,
                              index.scale,
                              FixedArray::kHeaderSize));
    __ j(not_equal, &not_found, Label::kNear);
    __ movp(rax, FieldOperand(cache,
                              index.reg,
                              index.scale,
                              FixedArray::kHeaderSize + kPointerSize));
    __ jmp(&done, Label::kNear);
  
    __ bind(&not_found);
    // Call runtime to perform the lookup.
    __ Push(cache);
    __ Push(key);
    __ CallRuntime(Runtime::kGetFromCache, 2);
  
    __ bind(&done);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitHasCachedArrayIndex(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    __ testl(FieldOperand(rax, String::kHashFieldOffset),
             Immediate(String::kContainsCachedArrayIndexMask));
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    __ j(zero, if_true);
    __ jmp(if_false);
  
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitGetCachedArrayIndex(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
    VisitForAccumulatorValue(args->at(0));
  
    __ AssertString(rax);
  
    __ movl(rax, FieldOperand(rax, String::kHashFieldOffset));
    DCHECK(String::kHashShift >= kSmiTagSize);
    __ IndexFromHash(rax, rax);
  
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitFastOneByteArrayJoin(CallRuntime* expr) {
    Label bailout, return_result, done, one_char_separator, long_separator,
        non_trivial_array, not_size_one_array, loop,
        loop_1, loop_1_condition, loop_2, loop_2_entry, loop_3, loop_3_entry;
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 2);
    // We will leave the separator on the stack until the end of the function.
    VisitForStackValue(args->at(1));
    // Load this to rax (= array)
    VisitForAccumulatorValue(args->at(0));
    // All aliases of the same register have disjoint lifetimes.
    Register array = rax;
    Register elements = no_reg;  // Will be rax.
  
    Register index = rdx;
  
    Register string_length = rcx;
  
    Register string = rsi;
  
    Register scratch = rbx;
  
    Register array_length = rdi;
    Register result_pos = no_reg;  // Will be rdi.
  
    Operand separator_operand =    Operand(rsp, 2 * kPointerSize);
    Operand result_operand =       Operand(rsp, 1 * kPointerSize);
    Operand array_length_operand = Operand(rsp, 0 * kPointerSize);
    // Separator operand is already pushed. Make room for the two
    // other stack fields, and clear the direction flag in anticipation
    // of calling CopyBytes.
    __ subp(rsp, Immediate(2 * kPointerSize));
    __ cld();
    // Check that the array is a JSArray
    __ JumpIfSmi(array, &bailout);
    __ CmpObjectType(array, JS_ARRAY_TYPE, scratch);
    __ j(not_equal, &bailout);
  
    // Check that the array has fast elements.
    __ CheckFastElements(scratch, &bailout);
  
    // Array has fast elements, so its length must be a smi.
    // If the array has length zero, return the empty string.
    __ movp(array_length, FieldOperand(array, JSArray::kLengthOffset));
    __ SmiCompare(array_length, Smi::FromInt(0));
    __ j(not_zero, &non_trivial_array);
    __ LoadRoot(rax, Heap::kempty_stringRootIndex);
    __ jmp(&return_result);
  
    // Save the array length on the stack.
    __ bind(&non_trivial_array);
    __ SmiToInteger32(array_length, array_length);
    __ movl(array_length_operand, array_length);
  
    // Save the FixedArray containing array's elements.
    // End of array's live range.
    elements = array;
    __ movp(elements, FieldOperand(array, JSArray::kElementsOffset));
    array = no_reg;
  
  
    // Check that all array elements are sequential one-byte strings, and
    // accumulate the sum of their lengths, as a smi-encoded value.
    __ Set(index, 0);
    __ Set(string_length, 0);
    // Loop condition: while (index < array_length).
    // Live loop registers: index(int32), array_length(int32), string(String*),
    //                      scratch, string_length(int32), elements(FixedArray*).
    if (generate_debug_code_) {
      __ cmpp(index, array_length);
      __ Assert(below, kNoEmptyArraysHereInEmitFastOneByteArrayJoin);
    }
    __ bind(&loop);
    __ movp(string, FieldOperand(elements,
                                 index,
                                 times_pointer_size,
                                 FixedArray::kHeaderSize));
    __ JumpIfSmi(string, &bailout);
    __ movp(scratch, FieldOperand(string, HeapObject::kMapOffset));
    __ movzxbl(scratch, FieldOperand(scratch, Map::kInstanceTypeOffset));
    __ andb(scratch, Immediate(
        kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask));
    __ cmpb(scratch, Immediate(kStringTag | kOneByteStringTag | kSeqStringTag));
    __ j(not_equal, &bailout);
    __ AddSmiField(string_length,
                   FieldOperand(string, SeqOneByteString::kLengthOffset));
    __ j(overflow, &bailout);
    __ incl(index);
    __ cmpl(index, array_length);
    __ j(less, &loop);
  
    // Live registers:
    // string_length: Sum of string lengths.
    // elements: FixedArray of strings.
    // index: Array length.
    // array_length: Array length.
  
    // If array_length is 1, return elements[0], a string.
    __ cmpl(array_length, Immediate(1));
    __ j(not_equal, &not_size_one_array);
    __ movp(rax, FieldOperand(elements, FixedArray::kHeaderSize));
    __ jmp(&return_result);
  
    __ bind(&not_size_one_array);
  
    // End of array_length live range.
    result_pos = array_length;
    array_length = no_reg;
  
    // Live registers:
    // string_length: Sum of string lengths.
    // elements: FixedArray of strings.
    // index: Array length.
  
    // Check that the separator is a sequential one-byte string.
    __ movp(string, separator_operand);
    __ JumpIfSmi(string, &bailout);
    __ movp(scratch, FieldOperand(string, HeapObject::kMapOffset));
    __ movzxbl(scratch, FieldOperand(scratch, Map::kInstanceTypeOffset));
    __ andb(scratch, Immediate(
        kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask));
    __ cmpb(scratch, Immediate(kStringTag | kOneByteStringTag | kSeqStringTag));
    __ j(not_equal, &bailout);
  
    // Live registers:
    // string_length: Sum of string lengths.
    // elements: FixedArray of strings.
    // index: Array length.
    // string: Separator string.
  
    // Add (separator length times (array_length - 1)) to string_length.
    __ SmiToInteger32(scratch,
                      FieldOperand(string, SeqOneByteString::kLengthOffset));
    __ decl(index);
    __ imull(scratch, index);
    __ j(overflow, &bailout);
    __ addl(string_length, scratch);
    __ j(overflow, &bailout);
  
    // Live registers and stack values:
    //   string_length: Total length of result string.
    //   elements: FixedArray of strings.
    __ AllocateOneByteString(result_pos, string_length, scratch, index, string,
                             &bailout);
    __ movp(result_operand, result_pos);
    __ leap(result_pos, FieldOperand(result_pos, SeqOneByteString::kHeaderSize));
  
    __ movp(string, separator_operand);
    __ SmiCompare(FieldOperand(string, SeqOneByteString::kLengthOffset),
                  Smi::FromInt(1));
    __ j(equal, &one_char_separator);
    __ j(greater, &long_separator);
  
  
    // Empty separator case:
    __ Set(index, 0);
    __ movl(scratch, array_length_operand);
    __ jmp(&loop_1_condition);
    // Loop condition: while (index < array_length).
    __ bind(&loop_1);
    // Each iteration of the loop concatenates one string to the result.
    // Live values in registers:
    //   index: which element of the elements array we are adding to the result.
    //   result_pos: the position to which we are currently copying characters.
    //   elements: the FixedArray of strings we are joining.
    //   scratch: array length.
  
    // Get string = array[index].
    __ movp(string, FieldOperand(elements, index,
                                 times_pointer_size,
                                 FixedArray::kHeaderSize));
    __ SmiToInteger32(string_length,
                      FieldOperand(string, String::kLengthOffset));
    __ leap(string,
           FieldOperand(string, SeqOneByteString::kHeaderSize));
    __ CopyBytes(result_pos, string, string_length);
    __ incl(index);
    __ bind(&loop_1_condition);
    __ cmpl(index, scratch);
    __ j(less, &loop_1);  // Loop while (index < array_length).
    __ jmp(&done);
  
    // Generic bailout code used from several places.
    __ bind(&bailout);
    __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
    __ jmp(&return_result);
  
  
    // One-character separator case
    __ bind(&one_char_separator);
    // Get the separator one-byte character value.
    // Register "string" holds the separator.
    __ movzxbl(scratch, FieldOperand(string, SeqOneByteString::kHeaderSize));
    __ Set(index, 0);
    // Jump into the loop after the code that copies the separator, so the first
    // element is not preceded by a separator
    __ jmp(&loop_2_entry);
    // Loop condition: while (index < length).
    __ bind(&loop_2);
    // Each iteration of the loop concatenates one string to the result.
    // Live values in registers:
    //   elements: The FixedArray of strings we are joining.
    //   index: which element of the elements array we are adding to the result.
    //   result_pos: the position to which we are currently copying characters.
    //   scratch: Separator character.
  
    // Copy the separator character to the result.
    __ movb(Operand(result_pos, 0), scratch);
    __ incp(result_pos);
  
    __ bind(&loop_2_entry);
    // Get string = array[index].
    __ movp(string, FieldOperand(elements, index,
                                 times_pointer_size,
                                 FixedArray::kHeaderSize));
    __ SmiToInteger32(string_length,
                      FieldOperand(string, String::kLengthOffset));
    __ leap(string,
           FieldOperand(string, SeqOneByteString::kHeaderSize));
    __ CopyBytes(result_pos, string, string_length);
    __ incl(index);
    __ cmpl(index, array_length_operand);
    __ j(less, &loop_2);  // End while (index < length).
    __ jmp(&done);
  
  
    // Long separator case (separator is more than one character).
    __ bind(&long_separator);
  
    // Make elements point to end of elements array, and index
    // count from -array_length to zero, so we don't need to maintain
    // a loop limit.
    __ movl(index, array_length_operand);
    __ leap(elements, FieldOperand(elements, index, times_pointer_size,
                                  FixedArray::kHeaderSize));
    __ negq(index);
  
    // Replace separator string with pointer to its first character, and
    // make scratch be its length.
    __ movp(string, separator_operand);
    __ SmiToInteger32(scratch,
                      FieldOperand(string, String::kLengthOffset));
    __ leap(string,
           FieldOperand(string, SeqOneByteString::kHeaderSize));
    __ movp(separator_operand, string);
  
    // Jump into the loop after the code that copies the separator, so the first
    // element is not preceded by a separator
    __ jmp(&loop_3_entry);
    // Loop condition: while (index < length).
    __ bind(&loop_3);
    // Each iteration of the loop concatenates one string to the result.
    // Live values in registers:
    //   index: which element of the elements array we are adding to the result.
    //   result_pos: the position to which we are currently copying characters.
    //   scratch: Separator length.
    //   separator_operand (rsp[0x10]): Address of first char of separator.
  
    // Copy the separator to the result.
    __ movp(string, separator_operand);
    __ movl(string_length, scratch);
    __ CopyBytes(result_pos, string, string_length, 2);
  
    __ bind(&loop_3_entry);
    // Get string = array[index].
    __ movp(string, Operand(elements, index, times_pointer_size, 0));
    __ SmiToInteger32(string_length,
                      FieldOperand(string, String::kLengthOffset));
    __ leap(string,
           FieldOperand(string, SeqOneByteString::kHeaderSize));
    __ CopyBytes(result_pos, string, string_length);
    __ incq(index);
    __ j(not_equal, &loop_3);  // Loop while (index < 0).
  
    __ bind(&done);
    __ movp(rax, result_operand);
  
    __ bind(&return_result);
    // Drop temp values from the stack, and restore context register.
    __ addp(rsp, Immediate(3 * kPointerSize));
    __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::EmitDebugIsActive(CallRuntime* expr) {
    DCHECK(expr->arguments()->length() == 0);
    ExternalReference debug_is_active =
        ExternalReference::debug_is_active_address(isolate());
    __ Move(kScratchRegister, debug_is_active);
    __ movzxbp(rax, Operand(kScratchRegister, 0));
    __ Integer32ToSmi(rax, rax);
    context()->Plug(rax);
  }
  
  
  void FullCodeGenerator::VisitCallRuntime(CallRuntime* expr) {
    if (expr->function() != NULL &&
        expr->function()->intrinsic_type == Runtime::INLINE) {
      Comment cmnt(masm_, "[ InlineRuntimeCall");
      EmitInlineRuntimeCall(expr);
      return;
    }
  
    Comment cmnt(masm_, "[ CallRuntime");
    ZoneList<Expression*>* args = expr->arguments();
    int arg_count = args->length();
  
    if (expr->is_jsruntime()) {
      // Push the builtins object as receiver.
      __ movp(rax, GlobalObjectOperand());
      __ Push(FieldOperand(rax, GlobalObject::kBuiltinsOffset));
  
      // Load the function from the receiver.
      __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, 0));
      __ Move(LoadDescriptor::NameRegister(), expr->name());
      if (FLAG_vector_ics) {
        __ Move(VectorLoadICDescriptor::SlotRegister(),
                SmiFromSlot(expr->CallRuntimeFeedbackSlot()));
        CallLoadIC(NOT_CONTEXTUAL);
      } else {
        CallLoadIC(NOT_CONTEXTUAL, expr->CallRuntimeFeedbackId());
      }
  
      // Push the target function under the receiver.
      __ Push(Operand(rsp, 0));
      __ movp(Operand(rsp, kPointerSize), rax);
  
      // Push the arguments ("left-to-right").
      for (int i = 0; i < arg_count; i++) {
        VisitForStackValue(args->at(i));
      }
  
      // Record source position of the IC call.
      SetSourcePosition(expr->position());
      CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
      __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
      __ CallStub(&stub);
  
      // Restore context register.
      __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
      context()->DropAndPlug(1, rax);
  
    } else {
      // Push the arguments ("left-to-right").
      for (int i = 0; i < arg_count; i++) {
        VisitForStackValue(args->at(i));
      }
  
      // Call the C runtime.
      __ CallRuntime(expr->function(), arg_count);
      context()->Plug(rax);
    }
  }
  
  
  void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
    switch (expr->op()) {
      case Token::DELETE: {
        Comment cmnt(masm_, "[ UnaryOperation (DELETE)");
        Property* property = expr->expression()->AsProperty();
        VariableProxy* proxy = expr->expression()->AsVariableProxy();
  
        if (property != NULL) {
          VisitForStackValue(property->obj());
          VisitForStackValue(property->key());
          __ Push(Smi::FromInt(strict_mode()));
          __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
          context()->Plug(rax);
        } else if (proxy != NULL) {
          Variable* var = proxy->var();
          // Delete of an unqualified identifier is disallowed in strict mode
          // but "delete this" is allowed.
          DCHECK(strict_mode() == SLOPPY || var->is_this());
          if (var->IsUnallocated()) {
            __ Push(GlobalObjectOperand());
            __ Push(var->name());
            __ Push(Smi::FromInt(SLOPPY));
            __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
            context()->Plug(rax);
          } else if (var->IsStackAllocated() || var->IsContextSlot()) {
            // Result of deleting non-global variables is false.  'this' is
            // not really a variable, though we implement it as one.  The
            // subexpression does not have side effects.
            context()->Plug(var->is_this());
          } else {
            // Non-global variable.  Call the runtime to try to delete from the
            // context where the variable was introduced.
            __ Push(context_register());
            __ Push(var->name());
            __ CallRuntime(Runtime::kDeleteLookupSlot, 2);
            context()->Plug(rax);
          }
        } else {
          // Result of deleting non-property, non-variable reference is true.
          // The subexpression may have side effects.
          VisitForEffect(expr->expression());
          context()->Plug(true);
        }
        break;
      }
  
      case Token::VOID: {
        Comment cmnt(masm_, "[ UnaryOperation (VOID)");
        VisitForEffect(expr->expression());
        context()->Plug(Heap::kUndefinedValueRootIndex);
        break;
      }
  
      case Token::NOT: {
        Comment cmnt(masm_, "[ UnaryOperation (NOT)");
        if (context()->IsEffect()) {
          // Unary NOT has no side effects so it's only necessary to visit the
          // subexpression.  Match the optimizing compiler by not branching.
          VisitForEffect(expr->expression());
        } else if (context()->IsTest()) {
          const TestContext* test = TestContext::cast(context());
          // The labels are swapped for the recursive call.
          VisitForControl(expr->expression(),
                          test->false_label(),
                          test->true_label(),
                          test->fall_through());
          context()->Plug(test->true_label(), test->false_label());
        } else {
          // We handle value contexts explicitly rather than simply visiting
          // for control and plugging the control flow into the context,
          // because we need to prepare a pair of extra administrative AST ids
          // for the optimizing compiler.
          DCHECK(context()->IsAccumulatorValue() || context()->IsStackValue());
          Label materialize_true, materialize_false, done;
          VisitForControl(expr->expression(),
                          &materialize_false,
                          &materialize_true,
                          &materialize_true);
          __ bind(&materialize_true);
          PrepareForBailoutForId(expr->MaterializeTrueId(), NO_REGISTERS);
          if (context()->IsAccumulatorValue()) {
            __ LoadRoot(rax, Heap::kTrueValueRootIndex);
          } else {
            __ PushRoot(Heap::kTrueValueRootIndex);
          }
          __ jmp(&done, Label::kNear);
          __ bind(&materialize_false);
          PrepareForBailoutForId(expr->MaterializeFalseId(), NO_REGISTERS);
          if (context()->IsAccumulatorValue()) {
            __ LoadRoot(rax, Heap::kFalseValueRootIndex);
          } else {
            __ PushRoot(Heap::kFalseValueRootIndex);
          }
          __ bind(&done);
        }
        break;
      }
  
      case Token::TYPEOF: {
        Comment cmnt(masm_, "[ UnaryOperation (TYPEOF)");
        { StackValueContext context(this);
          VisitForTypeofValue(expr->expression());
        }
        __ CallRuntime(Runtime::kTypeof, 1);
        context()->Plug(rax);
        break;
      }
  
      default:
        UNREACHABLE();
    }
  }
  
  
  void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
    DCHECK(expr->expression()->IsValidReferenceExpression());
  
    Comment cmnt(masm_, "[ CountOperation");
    SetSourcePosition(expr->position());
  
    Property* prop = expr->expression()->AsProperty();
    LhsKind assign_type = GetAssignType(prop);
  
    // Evaluate expression and get value.
    if (assign_type == VARIABLE) {
      DCHECK(expr->expression()->AsVariableProxy()->var() != NULL);
      AccumulatorValueContext context(this);
      EmitVariableLoad(expr->expression()->AsVariableProxy());
    } else {
      // Reserve space for result of postfix operation.
      if (expr->is_postfix() && !context()->IsEffect()) {
        __ Push(Smi::FromInt(0));
      }
      switch (assign_type) {
        case NAMED_PROPERTY: {
          VisitForStackValue(prop->obj());
          __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, 0));
          EmitNamedPropertyLoad(prop);
          break;
        }
  
        case NAMED_SUPER_PROPERTY: {
          VisitForStackValue(prop->obj()->AsSuperReference()->this_var());
          EmitLoadHomeObject(prop->obj()->AsSuperReference());
          __ Push(result_register());
          __ Push(MemOperand(rsp, kPointerSize));
          __ Push(result_register());
          EmitNamedSuperPropertyLoad(prop);
          break;
        }
  
        case KEYED_SUPER_PROPERTY: {
          VisitForStackValue(prop->obj()->AsSuperReference()->this_var());
          EmitLoadHomeObject(prop->obj()->AsSuperReference());
          __ Push(result_register());
          VisitForAccumulatorValue(prop->key());
          __ Push(result_register());
          __ Push(MemOperand(rsp, 2 * kPointerSize));
          __ Push(MemOperand(rsp, 2 * kPointerSize));
          __ Push(result_register());
          EmitKeyedSuperPropertyLoad(prop);
          break;
        }
  
        case KEYED_PROPERTY: {
          VisitForStackValue(prop->obj());
          VisitForStackValue(prop->key());
          // Leave receiver on stack
          __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, kPointerSize));
          // Copy of key, needed for later store.
          __ movp(LoadDescriptor::NameRegister(), Operand(rsp, 0));
          EmitKeyedPropertyLoad(prop);
          break;
        }
  
        case VARIABLE:
          UNREACHABLE();
      }
    }
  
    // We need a second deoptimization point after loading the value
    // in case evaluating the property load my have a side effect.
    if (assign_type == VARIABLE) {
      PrepareForBailout(expr->expression(), TOS_REG);
    } else {
      PrepareForBailoutForId(prop->LoadId(), TOS_REG);
    }
  
    // Inline smi case if we are in a loop.
    Label done, stub_call;
    JumpPatchSite patch_site(masm_);
    if (ShouldInlineSmiCase(expr->op())) {
      Label slow;
      patch_site.EmitJumpIfNotSmi(rax, &slow, Label::kNear);
  
      // Save result for postfix expressions.
      if (expr->is_postfix()) {
        if (!context()->IsEffect()) {
          // Save the result on the stack. If we have a named or keyed property
          // we store the result under the receiver that is currently on top
          // of the stack.
          switch (assign_type) {
            case VARIABLE:
              __ Push(rax);
              break;
            case NAMED_PROPERTY:
              __ movp(Operand(rsp, kPointerSize), rax);
              break;
            case NAMED_SUPER_PROPERTY:
              __ movp(Operand(rsp, 2 * kPointerSize), rax);
              break;
            case KEYED_PROPERTY:
              __ movp(Operand(rsp, 2 * kPointerSize), rax);
              break;
            case KEYED_SUPER_PROPERTY:
              __ movp(Operand(rsp, 3 * kPointerSize), rax);
              break;
          }
        }
      }
  
      SmiOperationExecutionMode mode;
      mode.Add(PRESERVE_SOURCE_REGISTER);
      mode.Add(BAILOUT_ON_NO_OVERFLOW);
      if (expr->op() == Token::INC) {
        __ SmiAddConstant(rax, rax, Smi::FromInt(1), mode, &done, Label::kNear);
      } else {
        __ SmiSubConstant(rax, rax, Smi::FromInt(1), mode, &done, Label::kNear);
      }
      __ jmp(&stub_call, Label::kNear);
      __ bind(&slow);
    }
  
    ToNumberStub convert_stub(isolate());
    __ CallStub(&convert_stub);
  
    // Save result for postfix expressions.
    if (expr->is_postfix()) {
      if (!context()->IsEffect()) {
        // Save the result on the stack. If we have a named or keyed property
        // we store the result under the receiver that is currently on top
        // of the stack.
        switch (assign_type) {
          case VARIABLE:
            __ Push(rax);
            break;
          case NAMED_PROPERTY:
            __ movp(Operand(rsp, kPointerSize), rax);
            break;
          case NAMED_SUPER_PROPERTY:
            __ movp(Operand(rsp, 2 * kPointerSize), rax);
            break;
          case KEYED_PROPERTY:
            __ movp(Operand(rsp, 2 * kPointerSize), rax);
            break;
          case KEYED_SUPER_PROPERTY:
            __ movp(Operand(rsp, 3 * kPointerSize), rax);
            break;
        }
      }
    }
  
    // Record position before stub call.
    SetSourcePosition(expr->position());
  
    // Call stub for +1/-1.
    __ bind(&stub_call);
    __ movp(rdx, rax);
    __ Move(rax, Smi::FromInt(1));
    Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), expr->binary_op(),
                                                NO_OVERWRITE).code();
    CallIC(code, expr->CountBinOpFeedbackId());
    patch_site.EmitPatchInfo();
    __ bind(&done);
  
    // Store the value returned in rax.
    switch (assign_type) {
      case VARIABLE:
        if (expr->is_postfix()) {
          // Perform the assignment as if via '='.
          { EffectContext context(this);
            EmitVariableAssignment(expr->expression()->AsVariableProxy()->var(),
                                   Token::ASSIGN);
            PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
            context.Plug(rax);
          }
          // For all contexts except kEffect: We have the result on
          // top of the stack.
          if (!context()->IsEffect()) {
            context()->PlugTOS();
          }
        } else {
          // Perform the assignment as if via '='.
          EmitVariableAssignment(expr->expression()->AsVariableProxy()->var(),
                                 Token::ASSIGN);
          PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
          context()->Plug(rax);
        }
        break;
      case NAMED_PROPERTY: {
        __ Move(StoreDescriptor::NameRegister(),
                prop->key()->AsLiteral()->value());
        __ Pop(StoreDescriptor::ReceiverRegister());
        CallStoreIC(expr->CountStoreFeedbackId());
        PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
        if (expr->is_postfix()) {
          if (!context()->IsEffect()) {
            context()->PlugTOS();
          }
        } else {
          context()->Plug(rax);
        }
        break;
      }
      case NAMED_SUPER_PROPERTY: {
        EmitNamedSuperPropertyStore(prop);
        if (expr->is_postfix()) {
          if (!context()->IsEffect()) {
            context()->PlugTOS();
          }
        } else {
          context()->Plug(rax);
        }
        break;
      }
      case KEYED_SUPER_PROPERTY: {
        EmitKeyedSuperPropertyStore(prop);
        if (expr->is_postfix()) {
          if (!context()->IsEffect()) {
            context()->PlugTOS();
          }
        } else {
          context()->Plug(rax);
        }
        break;
      }
      case KEYED_PROPERTY: {
        __ Pop(StoreDescriptor::NameRegister());
        __ Pop(StoreDescriptor::ReceiverRegister());
        Handle<Code> ic =
            CodeFactory::KeyedStoreIC(isolate(), strict_mode()).code();
        CallIC(ic, expr->CountStoreFeedbackId());
        PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
        if (expr->is_postfix()) {
          if (!context()->IsEffect()) {
            context()->PlugTOS();
          }
        } else {
          context()->Plug(rax);
        }
        break;
      }
    }
  }
  
  
  void FullCodeGenerator::VisitForTypeofValue(Expression* expr) {
    VariableProxy* proxy = expr->AsVariableProxy();
    DCHECK(!context()->IsEffect());
    DCHECK(!context()->IsTest());
  
    if (proxy != NULL && proxy->var()->IsUnallocated()) {
      Comment cmnt(masm_, "[ Global variable");
      __ Move(LoadDescriptor::NameRegister(), proxy->name());
      __ movp(LoadDescriptor::ReceiverRegister(), GlobalObjectOperand());
      if (FLAG_vector_ics) {
        __ Move(VectorLoadICDescriptor::SlotRegister(),
                SmiFromSlot(proxy->VariableFeedbackSlot()));
      }
      // Use a regular load, not a contextual load, to avoid a reference
      // error.
      CallLoadIC(NOT_CONTEXTUAL);
      PrepareForBailout(expr, TOS_REG);
      context()->Plug(rax);
    } else if (proxy != NULL && proxy->var()->IsLookupSlot()) {
      Comment cmnt(masm_, "[ Lookup slot");
      Label done, slow;
  
      // Generate code for loading from variables potentially shadowed
      // by eval-introduced variables.
      EmitDynamicLookupFastCase(proxy, INSIDE_TYPEOF, &slow, &done);
  
      __ bind(&slow);
      __ Push(rsi);
      __ Push(proxy->name());
      __ CallRuntime(Runtime::kLoadLookupSlotNoReferenceError, 2);
      PrepareForBailout(expr, TOS_REG);
      __ bind(&done);
  
      context()->Plug(rax);
    } else {
      // This expression cannot throw a reference error at the top level.
      VisitInDuplicateContext(expr);
    }
  }
  
  
  void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
                                                   Expression* sub_expr,
                                                   Handle<String> check) {
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    { AccumulatorValueContext context(this);
      VisitForTypeofValue(sub_expr);
    }
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
  
    Factory* factory = isolate()->factory();
    if (String::Equals(check, factory->number_string())) {
      __ JumpIfSmi(rax, if_true);
      __ movp(rax, FieldOperand(rax, HeapObject::kMapOffset));
      __ CompareRoot(rax, Heap::kHeapNumberMapRootIndex);
      Split(equal, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->string_string())) {
      __ JumpIfSmi(rax, if_false);
      // Check for undetectable objects => false.
      __ CmpObjectType(rax, FIRST_NONSTRING_TYPE, rdx);
      __ j(above_equal, if_false);
      __ testb(FieldOperand(rdx, Map::kBitFieldOffset),
               Immediate(1 << Map::kIsUndetectable));
      Split(zero, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->symbol_string())) {
      __ JumpIfSmi(rax, if_false);
      __ CmpObjectType(rax, SYMBOL_TYPE, rdx);
      Split(equal, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->boolean_string())) {
      __ CompareRoot(rax, Heap::kTrueValueRootIndex);
      __ j(equal, if_true);
      __ CompareRoot(rax, Heap::kFalseValueRootIndex);
      Split(equal, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->undefined_string())) {
      __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
      __ j(equal, if_true);
      __ JumpIfSmi(rax, if_false);
      // Check for undetectable objects => true.
      __ movp(rdx, FieldOperand(rax, HeapObject::kMapOffset));
      __ testb(FieldOperand(rdx, Map::kBitFieldOffset),
               Immediate(1 << Map::kIsUndetectable));
      Split(not_zero, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->function_string())) {
      __ JumpIfSmi(rax, if_false);
      STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
      __ CmpObjectType(rax, JS_FUNCTION_TYPE, rdx);
      __ j(equal, if_true);
      __ CmpInstanceType(rdx, JS_FUNCTION_PROXY_TYPE);
      Split(equal, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->object_string())) {
      __ JumpIfSmi(rax, if_false);
      __ CompareRoot(rax, Heap::kNullValueRootIndex);
      __ j(equal, if_true);
      __ CmpObjectType(rax, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE, rdx);
      __ j(below, if_false);
      __ CmpInstanceType(rdx, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
      __ j(above, if_false);
      // Check for undetectable objects => false.
      __ testb(FieldOperand(rdx, Map::kBitFieldOffset),
               Immediate(1 << Map::kIsUndetectable));
      Split(zero, if_true, if_false, fall_through);
    } else {
      if (if_false != fall_through) __ jmp(if_false);
    }
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
    Comment cmnt(masm_, "[ CompareOperation");
    SetSourcePosition(expr->position());
  
    // First we try a fast inlined version of the compare when one of
    // the operands is a literal.
    if (TryLiteralCompare(expr)) return;
  
    // Always perform the comparison for its control flow.  Pack the result
    // into the expression's context after the comparison is performed.
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    Token::Value op = expr->op();
    VisitForStackValue(expr->left());
    switch (op) {
      case Token::IN:
        VisitForStackValue(expr->right());
        __ InvokeBuiltin(Builtins::IN, CALL_FUNCTION);
        PrepareForBailoutBeforeSplit(expr, false, NULL, NULL);
        __ CompareRoot(rax, Heap::kTrueValueRootIndex);
        Split(equal, if_true, if_false, fall_through);
        break;
  
      case Token::INSTANCEOF: {
        VisitForStackValue(expr->right());
        InstanceofStub stub(isolate(), InstanceofStub::kNoFlags);
        __ CallStub(&stub);
        PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
        __ testp(rax, rax);
         // The stub returns 0 for true.
        Split(zero, if_true, if_false, fall_through);
        break;
      }
  
      default: {
        VisitForAccumulatorValue(expr->right());
        Condition cc = CompareIC::ComputeCondition(op);
        __ Pop(rdx);
  
        bool inline_smi_code = ShouldInlineSmiCase(op);
        JumpPatchSite patch_site(masm_);
        if (inline_smi_code) {
          Label slow_case;
          __ movp(rcx, rdx);
          __ orp(rcx, rax);
          patch_site.EmitJumpIfNotSmi(rcx, &slow_case, Label::kNear);
          __ cmpp(rdx, rax);
          Split(cc, if_true, if_false, NULL);
          __ bind(&slow_case);
        }
  
        // Record position and call the compare IC.
        SetSourcePosition(expr->position());
        Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
        CallIC(ic, expr->CompareOperationFeedbackId());
        patch_site.EmitPatchInfo();
  
        PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
        __ testp(rax, rax);
        Split(cc, if_true, if_false, fall_through);
      }
    }
  
    // Convert the result of the comparison into one expected for this
    // expression's context.
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::EmitLiteralCompareNil(CompareOperation* expr,
                                                Expression* sub_expr,
                                                NilValue nil) {
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false,
                           &if_true, &if_false, &fall_through);
  
    VisitForAccumulatorValue(sub_expr);
    PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
    if (expr->op() == Token::EQ_STRICT) {
      Heap::RootListIndex nil_value = nil == kNullValue ?
          Heap::kNullValueRootIndex :
          Heap::kUndefinedValueRootIndex;
      __ CompareRoot(rax, nil_value);
      Split(equal, if_true, if_false, fall_through);
    } else {
      Handle<Code> ic = CompareNilICStub::GetUninitialized(isolate(), nil);
      CallIC(ic, expr->CompareOperationFeedbackId());
      __ testp(rax, rax);
      Split(not_zero, if_true, if_false, fall_through);
    }
    context()->Plug(if_true, if_false);
  }
  
  
  void FullCodeGenerator::VisitThisFunction(ThisFunction* expr) {
    __ movp(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
    context()->Plug(rax);
  }
  
  
  Register FullCodeGenerator::result_register() {
    return rax;
  }
  
  
  Register FullCodeGenerator::context_register() {
    return rsi;
  }
  
  
  void FullCodeGenerator::StoreToFrameField(int frame_offset, Register value) {
    DCHECK(IsAligned(frame_offset, kPointerSize));
    __ movp(Operand(rbp, frame_offset), value);
  }
  
  
  void FullCodeGenerator::LoadContextField(Register dst, int context_index) {
    __ movp(dst, ContextOperand(rsi, context_index));
  }
  
  
  void FullCodeGenerator::PushFunctionArgumentForContextAllocation() {
    Scope* declaration_scope = scope()->DeclarationScope();
    if (declaration_scope->is_global_scope() ||
        declaration_scope->is_module_scope()) {
      // Contexts nested in the native context have a canonical empty function
      // as their closure, not the anonymous closure containing the global
      // code.  Pass a smi sentinel and let the runtime look up the empty
      // function.
      __ Push(Smi::FromInt(0));
    } else if (declaration_scope->is_eval_scope()) {
      // Contexts created by a call to eval have the same closure as the
      // context calling eval, not the anonymous closure containing the eval
      // code.  Fetch it from the context.
      __ Push(ContextOperand(rsi, Context::CLOSURE_INDEX));
    } else {
      DCHECK(declaration_scope->is_function_scope());
      __ Push(Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
    }
  }
  
  
  // ----------------------------------------------------------------------------
  // Non-local control flow support.
  
  
  void FullCodeGenerator::EnterFinallyBlock() {
    DCHECK(!result_register().is(rdx));
    DCHECK(!result_register().is(rcx));
    // Cook return address on top of stack (smi encoded Code* delta)
    __ PopReturnAddressTo(rdx);
    __ Move(rcx, masm_->CodeObject());
    __ subp(rdx, rcx);
    __ Integer32ToSmi(rdx, rdx);
    __ Push(rdx);
  
    // Store result register while executing finally block.
    __ Push(result_register());
  
    // Store pending message while executing finally block.
    ExternalReference pending_message_obj =
        ExternalReference::address_of_pending_message_obj(isolate());
    __ Load(rdx, pending_message_obj);
    __ Push(rdx);
  
    ExternalReference has_pending_message =
        ExternalReference::address_of_has_pending_message(isolate());
    __ Load(rdx, has_pending_message);
    __ Integer32ToSmi(rdx, rdx);
    __ Push(rdx);
  
    ExternalReference pending_message_script =
        ExternalReference::address_of_pending_message_script(isolate());
    __ Load(rdx, pending_message_script);
    __ Push(rdx);
  }
  
  
  void FullCodeGenerator::ExitFinallyBlock() {
    DCHECK(!result_register().is(rdx));
    DCHECK(!result_register().is(rcx));
    // Restore pending message from stack.
    __ Pop(rdx);
    ExternalReference pending_message_script =
        ExternalReference::address_of_pending_message_script(isolate());
    __ Store(pending_message_script, rdx);
  
    __ Pop(rdx);
    __ SmiToInteger32(rdx, rdx);
    ExternalReference has_pending_message =
        ExternalReference::address_of_has_pending_message(isolate());
    __ Store(has_pending_message, rdx);
  
    __ Pop(rdx);
    ExternalReference pending_message_obj =
        ExternalReference::address_of_pending_message_obj(isolate());
    __ Store(pending_message_obj, rdx);
  
    // Restore result register from stack.
    __ Pop(result_register());
  
    // Uncook return address.
    __ Pop(rdx);
    __ SmiToInteger32(rdx, rdx);
    __ Move(rcx, masm_->CodeObject());
    __ addp(rdx, rcx);
    __ jmp(rdx);
  }
  
  
  #undef __
  
  #define __ ACCESS_MASM(masm())
  
  FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
      int* stack_depth,
      int* context_length) {
    // The macros used here must preserve the result register.
  
    // Because the handler block contains the context of the finally
    // code, we can restore it directly from there for the finally code
    // rather than iteratively unwinding contexts via their previous
    // links.
    __ Drop(*stack_depth);  // Down to the handler block.
    if (*context_length > 0) {
      // Restore the context to its dedicated register and the stack.
      __ movp(rsi, Operand(rsp, StackHandlerConstants::kContextOffset));
      __ movp(Operand(rbp, StandardFrameConstants::kContextOffset), rsi);
    }
    __ PopTryHandler();
    __ call(finally_entry_);
  
    *stack_depth = 0;
    *context_length = 0;
    return previous_;
  }
  
  
  #undef __
  
  
  static const byte kJnsInstruction = 0x79;
  static const byte kNopByteOne = 0x66;
  static const byte kNopByteTwo = 0x90;
  #ifdef DEBUG
  static const byte kCallInstruction = 0xe8;
  #endif
  
  
  void BackEdgeTable::PatchAt(Code* unoptimized_code,
                              Address pc,
                              BackEdgeState target_state,
                              Code* replacement_code) {
    Address call_target_address = pc - kIntSize;
    Address jns_instr_address = call_target_address - 3;
    Address jns_offset_address = call_target_address - 2;
  
    switch (target_state) {
      case INTERRUPT:
        //     sub <profiling_counter>, <delta>  ;; Not changed
        //     jns ok
        //     call <interrupt stub>
        //   ok:
        *jns_instr_address = kJnsInstruction;
        *jns_offset_address = kJnsOffset;
        break;
      case ON_STACK_REPLACEMENT:
      case OSR_AFTER_STACK_CHECK:
        //     sub <profiling_counter>, <delta>  ;; Not changed
        //     nop
        //     nop
        //     call <on-stack replacment>
        //   ok:
        *jns_instr_address = kNopByteOne;
        *jns_offset_address = kNopByteTwo;
        break;
    }
  
    Assembler::set_target_address_at(call_target_address,
                                     unoptimized_code,
                                     replacement_code->entry());
    unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
        unoptimized_code, call_target_address, replacement_code);
  }
  
  
  BackEdgeTable::BackEdgeState BackEdgeTable::GetBackEdgeState(
      Isolate* isolate,
      Code* unoptimized_code,
      Address pc) {
    Address call_target_address = pc - kIntSize;
    Address jns_instr_address = call_target_address - 3;
    DCHECK_EQ(kCallInstruction, *(call_target_address - 1));
  
    if (*jns_instr_address == kJnsInstruction) {
      DCHECK_EQ(kJnsOffset, *(call_target_address - 2));
      DCHECK_EQ(isolate->builtins()->InterruptCheck()->entry(),
                Assembler::target_address_at(call_target_address,
                                             unoptimized_code));
      return INTERRUPT;
    }
  
    DCHECK_EQ(kNopByteOne, *jns_instr_address);
    DCHECK_EQ(kNopByteTwo, *(call_target_address - 2));
  
    if (Assembler::target_address_at(call_target_address,
                                     unoptimized_code) ==
        isolate->builtins()->OnStackReplacement()->entry()) {
      return ON_STACK_REPLACEMENT;
    }
  
    DCHECK_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
              Assembler::target_address_at(call_target_address,
                                           unoptimized_code));
    return OSR_AFTER_STACK_CHECK;
  }
  
  
  } }  // namespace v8::internal
  
  #endif  // V8_TARGET_ARCH_X64
  