src/x64/full-codegen-x64.cc - platform/external/v8 - Git at Google

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 #include "v8.h"

 #if defined(V8_TARGET_ARCH_X64)

 #include "code-stubs.h"
 #include "codegen-inl.h"
 #include "compiler.h"
 #include "debug.h"
 #include "full-codegen.h"
 #include "parser.h"
 #include "scopes.h"
 #include "stub-cache.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() {
     ASSERT(patch_site_.is_bound() == info_emitted_);
   }

   void EmitJumpIfNotSmi(Register reg, NearLabel* target) {
     __ testb(reg, Immediate(kSmiTagMask));
     EmitJump(not_carry, target);   // Always taken before patched.
   }

   void EmitJumpIfSmi(Register reg, NearLabel* target) {
     __ testb(reg, Immediate(kSmiTagMask));
     EmitJump(carry, target);  // Never taken before patched.
   }

   void EmitPatchInfo() {
     int delta_to_patch_site = masm_->SizeOfCodeGeneratedSince(&patch_site_);
     ASSERT(is_int8(delta_to_patch_site));
     __ testl(rax, Immediate(delta_to_patch_site));
 #ifdef DEBUG
     info_emitted_ = true;
 #endif
   }

   bool is_bound() const { return patch_site_.is_bound(); }

  private:
   // jc will be patched with jz, jnc will become jnz.
   void EmitJump(Condition cc, NearLabel* target) {
     ASSERT(!patch_site_.is_bound() && !info_emitted_);
     ASSERT(cc == carry || cc == not_carry);
     __ bind(&patch_site_);
     __ j(cc, target);
   }

   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 (ie, 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) {
   ASSERT(info_ == NULL);
   info_ = info;
   SetFunctionPosition(function());
   Comment cmnt(masm_, "[ function compiled by full code generator");

 #ifdef DEBUG
   if (strlen(FLAG_stop_at) > 0 &&
       info->function()->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
     __ int3();
   }
 #endif
   __ push(rbp);  // Caller's frame pointer.
   __ movq(rbp, rsp);
   __ push(rsi);  // Callee's context.
   __ push(rdi);  // Callee's JS Function.

   { Comment cmnt(masm_, "[ Allocate locals");
     int locals_count = scope()->num_stack_slots();
     if (locals_count == 1) {
       __ PushRoot(Heap::kUndefinedValueRootIndex);
     } else if (locals_count > 1) {
       __ LoadRoot(rdx, Heap::kUndefinedValueRootIndex);
       for (int i = 0; i < locals_count; i++) {
         __ push(rdx);
       }
     }
   }

   bool function_in_register = true;

   // Possibly allocate a local context.
   int heap_slots = scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
   if (heap_slots > 0) {
     Comment cmnt(masm_, "[ Allocate local context");
     // Argument to NewContext is the function, which is still in rdi.
     __ push(rdi);
     if (heap_slots <= FastNewContextStub::kMaximumSlots) {
       FastNewContextStub stub(heap_slots);
       __ CallStub(&stub);
     } else {
       __ CallRuntime(Runtime::kNewContext, 1);
     }
     function_in_register = false;
     // Context is returned in both rax and rsi.  It replaces the context
     // passed to us.  It's saved in the stack and kept live in rsi.
     __ movq(Operand(rbp, StandardFrameConstants::kContextOffset), rsi);

     // Copy any necessary parameters into the context.
     int num_parameters = scope()->num_parameters();
     for (int i = 0; i < num_parameters; i++) {
       Slot* slot = scope()->parameter(i)->AsSlot();
       if (slot != NULL && slot->type() == Slot::CONTEXT) {
         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
             (num_parameters - 1 - i) * kPointerSize;
         // Load parameter from stack.
         __ movq(rax, Operand(rbp, parameter_offset));
         // Store it in the context.
         int context_offset = Context::SlotOffset(slot->index());
         __ movq(Operand(rsi, context_offset), rax);
         // Update the write barrier. This clobbers all involved
         // registers, so we have use a third register to avoid
         // clobbering rsi.
         __ movq(rcx, rsi);
         __ RecordWrite(rcx, context_offset, rax, rbx);
       }
     }
   }

   // 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 offset = scope()->num_parameters() * kPointerSize;
     __ lea(rdx,
            Operand(rbp, StandardFrameConstants::kCallerSPOffset + offset));
     __ push(rdx);
     __ Push(Smi::FromInt(scope()->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 stub(ArgumentsAccessStub::NEW_OBJECT);
     __ CallStub(&stub);
     // Store new arguments object in both "arguments" and ".arguments" slots.
     __ movq(rcx, rax);
     Move(arguments->AsSlot(), rax, rbx, rdx);
     Slot* dot_arguments_slot = scope()->arguments_shadow()->AsSlot();
     Move(dot_arguments_slot, rcx, 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 {
     { Comment cmnt(masm_, "[ Declarations");
       // For named function expressions, declare the function name as a
       // constant.
       if (scope()->is_function_scope() && scope()->function() != NULL) {
         EmitDeclaration(scope()->function(), Variable::CONST, NULL);
       }
       VisitDeclarations(scope()->declarations());
     }

     { Comment cmnt(masm_, "[ Stack check");
       PrepareForBailout(info->function(), NO_REGISTERS);
       NearLabel ok;
       __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
       __ j(above_equal, &ok);
       StackCheckStub stub;
       __ CallStub(&stub);
       __ bind(&ok);
     }

     { Comment cmnt(masm_, "[ Body");
       ASSERT(loop_depth() == 0);
       VisitStatements(function()->body());
       ASSERT(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::EmitStackCheck(IterationStatement* stmt) {
   Comment cmnt(masm_, "[ Stack check");
   NearLabel ok;
   __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
   __ j(above_equal, &ok);
   StackCheckStub stub;
   __ CallStub(&stub);
   // 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.
   RecordStackCheck(stmt->OsrEntryId());

   // Loop stack checks can be patched to perform on-stack replacement. In
   // order to decide whether or not to perform OSR we embed the loop depth
   // in a test instruction after the call so we can extract it from the OSR
   // builtin.
   ASSERT(loop_depth() > 0);
   __ testl(rax, Immediate(Min(loop_depth(), Code::kMaxLoopNestingMarker)));

   __ 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);
     }
 #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.
     __ movq(rsp, rbp);
     __ pop(rbp);

     int arguments_bytes = (scope()->num_parameters() + 1) * kPointerSize;
     __ Ret(arguments_bytes, rcx);

 #ifdef ENABLE_DEBUGGER_SUPPORT
     // Add padding that will be overwritten by a debugger breakpoint.  We
     // have just generated at least 7 bytes: "movq rsp, rbp; pop rbp; ret k"
     // (3 + 1 + 3).
     const int kPadding = Assembler::kJSReturnSequenceLength - 7;
     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.
     ASSERT(Assembler::kJSReturnSequenceLength <=
            masm_->SizeOfCodeGeneratedSince(&check_exit_codesize));
 #endif
   }
 }


 void FullCodeGenerator::EffectContext::Plug(Slot* slot) const {
 }


 void FullCodeGenerator::AccumulatorValueContext::Plug(Slot* slot) const {
   MemOperand slot_operand = codegen()->EmitSlotSearch(slot, result_register());
   __ movq(result_register(), slot_operand);
 }


 void FullCodeGenerator::StackValueContext::Plug(Slot* slot) const {
   MemOperand slot_operand = codegen()->EmitSlotSearch(slot, result_register());
   __ push(slot_operand);
 }


 void FullCodeGenerator::TestContext::Plug(Slot* slot) const {
   codegen()->Move(result_register(), slot);
   codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
   codegen()->DoTest(true_label_, false_label_, fall_through_);
 }


 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(TOS_REG,
                                           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(true_label_, false_label_, fall_through_);
   }
 }


 void FullCodeGenerator::EffectContext::Plug(Handle<Object> lit) const {
 }


 void FullCodeGenerator::AccumulatorValueContext::Plug(
     Handle<Object> lit) const {
   __ Move(result_register(), lit);
 }


 void FullCodeGenerator::StackValueContext::Plug(Handle<Object> lit) const {
   __ Push(lit);
 }


 void FullCodeGenerator::TestContext::Plug(Handle<Object> lit) const {
   codegen()->PrepareForBailoutBeforeSplit(TOS_REG,
                                           true,
                                           true_label_,
                                           false_label_);
   ASSERT(!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(true_label_, false_label_, fall_through_);
   }
 }


 void FullCodeGenerator::EffectContext::DropAndPlug(int count,
                                                    Register reg) const {
   ASSERT(count > 0);
   __ Drop(count);
 }


 void FullCodeGenerator::AccumulatorValueContext::DropAndPlug(
     int count,
     Register reg) const {
   ASSERT(count > 0);
   __ Drop(count);
   __ Move(result_register(), reg);
 }


 void FullCodeGenerator::StackValueContext::DropAndPlug(int count,
                                                        Register reg) const {
   ASSERT(count > 0);
   if (count > 1) __ Drop(count - 1);
   __ movq(Operand(rsp, 0), reg);
 }


 void FullCodeGenerator::TestContext::DropAndPlug(int count,
                                                  Register reg) const {
   ASSERT(count > 0);
   // For simplicity we always test the accumulator register.
   __ Drop(count);
   __ Move(result_register(), reg);
   codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
   codegen()->DoTest(true_label_, false_label_, fall_through_);
 }


 void FullCodeGenerator::EffectContext::Plug(Label* materialize_true,
                                             Label* materialize_false) const {
   ASSERT(materialize_true == materialize_false);
   __ bind(materialize_true);
 }


 void FullCodeGenerator::AccumulatorValueContext::Plug(
     Label* materialize_true,
     Label* materialize_false) const {
   NearLabel done;
   __ bind(materialize_true);
   __ Move(result_register(), Factory::true_value());
   __ jmp(&done);
   __ bind(materialize_false);
   __ Move(result_register(), Factory::false_value());
   __ bind(&done);
 }


 void FullCodeGenerator::StackValueContext::Plug(
     Label* materialize_true,
     Label* materialize_false) const {
   NearLabel done;
   __ bind(materialize_true);
   __ Push(Factory::true_value());
   __ jmp(&done);
   __ bind(materialize_false);
   __ Push(Factory::false_value());
   __ bind(&done);
 }


 void FullCodeGenerator::TestContext::Plug(Label* materialize_true,
                                           Label* materialize_false) const {
   ASSERT(materialize_true == true_label_);
   ASSERT(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(TOS_REG,
                                           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(Label* if_true,
                                Label* if_false,
                                Label* fall_through) {
   // Emit the inlined tests assumed by the stub.
   __ CompareRoot(result_register(), Heap::kUndefinedValueRootIndex);
   __ j(equal, if_false);
   __ CompareRoot(result_register(), Heap::kTrueValueRootIndex);
   __ j(equal, if_true);
   __ CompareRoot(result_register(), Heap::kFalseValueRootIndex);
   __ j(equal, if_false);
   STATIC_ASSERT(kSmiTag == 0);
   __ SmiCompare(result_register(), Smi::FromInt(0));
   __ j(equal, if_false);
   Condition is_smi = masm_->CheckSmi(result_register());
   __ j(is_smi, if_true);

   // Call the ToBoolean stub for all other cases.
   ToBooleanStub stub;
   __ push(result_register());
   __ CallStub(&stub);
   __ testq(rax, rax);

   // 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::EmitSlotSearch(Slot* slot, Register scratch) {
   switch (slot->type()) {
     case Slot::PARAMETER:
     case Slot::LOCAL:
       return Operand(rbp, SlotOffset(slot));
     case Slot::CONTEXT: {
       int context_chain_length =
           scope()->ContextChainLength(slot->var()->scope());
       __ LoadContext(scratch, context_chain_length);
       return ContextOperand(scratch, slot->index());
     }
     case Slot::LOOKUP:
       UNREACHABLE();
   }
   UNREACHABLE();
   return Operand(rax, 0);
 }


 void FullCodeGenerator::Move(Register destination, Slot* source) {
   MemOperand location = EmitSlotSearch(source, destination);
   __ movq(destination, location);
 }


 void FullCodeGenerator::Move(Slot* dst,
                              Register src,
                              Register scratch1,
                              Register scratch2) {
   ASSERT(dst->type() != Slot::LOOKUP);  // Not yet implemented.
   ASSERT(!scratch1.is(src) && !scratch2.is(src));
   MemOperand location = EmitSlotSearch(dst, scratch1);
   __ movq(location, src);
   // Emit the write barrier code if the location is in the heap.
   if (dst->type() == Slot::CONTEXT) {
     int offset = FixedArray::kHeaderSize + dst->index() * kPointerSize;
     __ RecordWrite(scratch1, offset, src, scratch2);
   }
 }


 void FullCodeGenerator::PrepareForBailoutBeforeSplit(State state,
                                                      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;

   NearLabel skip;
   if (should_normalize) __ jmp(&skip);

   ForwardBailoutStack* current = forward_bailout_stack_;
   while (current != NULL) {
     PrepareForBailout(current->expr(), state);
     current = current->parent();
   }

   if (should_normalize) {
     __ CompareRoot(rax, Heap::kTrueValueRootIndex);
     Split(equal, if_true, if_false, NULL);
     __ bind(&skip);
   }
 }


 void FullCodeGenerator::EmitDeclaration(Variable* variable,
                                         Variable::Mode mode,
                                         FunctionLiteral* function) {
   Comment cmnt(masm_, "[ Declaration");
   ASSERT(variable != NULL);  // Must have been resolved.
   Slot* slot = variable->AsSlot();
   Property* prop = variable->AsProperty();

   if (slot != NULL) {
     switch (slot->type()) {
       case Slot::PARAMETER:
       case Slot::LOCAL:
         if (mode == Variable::CONST) {
           __ LoadRoot(kScratchRegister, Heap::kTheHoleValueRootIndex);
           __ movq(Operand(rbp, SlotOffset(slot)), kScratchRegister);
         } else if (function != NULL) {
           VisitForAccumulatorValue(function);
           __ movq(Operand(rbp, SlotOffset(slot)), result_register());
         }
         break;

       case Slot::CONTEXT:
         // We bypass the general EmitSlotSearch because we know more about
         // this specific context.

         // The variable in the decl always resides in the current context.
         ASSERT_EQ(0, scope()->ContextChainLength(variable->scope()));
         if (FLAG_debug_code) {
           // Check if we have the correct context pointer.
           __ movq(rbx, ContextOperand(rsi, Context::FCONTEXT_INDEX));
           __ cmpq(rbx, rsi);
           __ Check(equal, "Unexpected declaration in current context.");
         }
         if (mode == Variable::CONST) {
           __ LoadRoot(kScratchRegister, Heap::kTheHoleValueRootIndex);
           __ movq(ContextOperand(rsi, slot->index()), kScratchRegister);
           // No write barrier since the hole value is in old space.
         } else if (function != NULL) {
           VisitForAccumulatorValue(function);
           __ movq(ContextOperand(rsi, slot->index()), result_register());
           int offset = Context::SlotOffset(slot->index());
           __ movq(rbx, rsi);
           __ RecordWrite(rbx, offset, result_register(), rcx);
         }
         break;

       case Slot::LOOKUP: {
         __ push(rsi);
         __ Push(variable->name());
         // Declaration nodes are always introduced in one of two modes.
         ASSERT(mode == Variable::VAR || mode == Variable::CONST);
         PropertyAttributes attr = (mode == Variable::VAR) ? NONE : READ_ONLY;
         __ 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 (mode == Variable::CONST) {
           __ PushRoot(Heap::kTheHoleValueRootIndex);
         } else if (function != NULL) {
           VisitForStackValue(function);
         } else {
           __ Push(Smi::FromInt(0));  // no initial value!
         }
         __ CallRuntime(Runtime::kDeclareContextSlot, 4);
         break;
       }
     }

   } else if (prop != NULL) {
     if (function != NULL || mode == Variable::CONST) {
       // We are declaring a function or constant that rewrites to a
       // property.  Use (keyed) IC to set the initial value.  We
       // cannot visit the rewrite because it's shared and we risk
       // recording duplicate AST IDs for bailouts from optimized code.
       ASSERT(prop->obj()->AsVariableProxy() != NULL);
       { AccumulatorValueContext for_object(this);
         EmitVariableLoad(prop->obj()->AsVariableProxy()->var());
       }
       if (function != NULL) {
         __ push(rax);
         VisitForAccumulatorValue(function);
         __ pop(rdx);
       } else {
         __ movq(rdx, rax);
         __ LoadRoot(rax, Heap::kTheHoleValueRootIndex);
       }
       ASSERT(prop->key()->AsLiteral() != NULL &&
              prop->key()->AsLiteral()->handle()->IsSmi());
       __ Move(rcx, prop->key()->AsLiteral()->handle());

       Handle<Code> ic(Builtins::builtin(is_strict()
           ? Builtins::KeyedStoreIC_Initialize_Strict
           : Builtins::KeyedStoreIC_Initialize));
       EmitCallIC(ic, RelocInfo::CODE_TARGET);
     }
   }
 }


 void FullCodeGenerator::VisitDeclaration(Declaration* decl) {
   EmitDeclaration(decl->proxy()->var(), decl->mode(), decl->fun());
 }


 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(is_eval() ? 1 : 0));
   __ Push(Smi::FromInt(strict_mode_flag()));
   __ CallRuntime(Runtime::kDeclareGlobals, 4);
   // 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()->entry_label()->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 '==='.
     __ movq(rdx, Operand(rsp, 0));  // Switch value.
     bool inline_smi_code = ShouldInlineSmiCase(Token::EQ_STRICT);
     JumpPatchSite patch_site(masm_);
     if (inline_smi_code) {
       NearLabel slow_case;
       __ movq(rcx, rdx);
       __ or_(rcx, rax);
       patch_site.EmitJumpIfNotSmi(rcx, &slow_case);

       __ cmpq(rdx, rax);
       __ j(not_equal, &next_test);
       __ Drop(1);  // Switch value is no longer needed.
       __ jmp(clause->body_target()->entry_label());
       __ bind(&slow_case);
     }

     // Record position before stub call for type feedback.
     SetSourcePosition(clause->position());
     Handle<Code> ic = CompareIC::GetUninitialized(Token::EQ_STRICT);
     EmitCallIC(ic, &patch_site);

     __ testq(rax, rax);
     __ j(not_equal, &next_test);
     __ Drop(1);  // Switch value is no longer needed.
     __ jmp(clause->body_target()->entry_label());
   }

   // 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_target());
   } else {
     __ jmp(default_clause->body_target()->entry_label());
   }

   // 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()->entry_label());
     VisitStatements(clause->statements());
   }

   __ bind(nested_statement.break_target());
   PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
 }


 void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   Comment cmnt(masm_, "[ ForInStatement");
   SetStatementPosition(stmt);

   Label loop, exit;
   ForIn loop_statement(this, stmt);
   increment_loop_depth();

   // Get the object to enumerate over. Both SpiderMonkey and JSC
   // ignore null and undefined in contrast to the specification; see
   // ECMA-262 section 12.6.4.
   VisitForAccumulatorValue(stmt->enumerable());
   __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
   __ j(equal, &exit);
   Register null_value = rdi;
   __ LoadRoot(null_value, Heap::kNullValueRootIndex);
   __ cmpq(rax, null_value);
   __ j(equal, &exit);

   // Convert the object to a JS object.
   Label convert, done_convert;
   __ JumpIfSmi(rax, &convert);
   __ CmpObjectType(rax, FIRST_JS_OBJECT_TYPE, rcx);
   __ j(above_equal, &done_convert);
   __ bind(&convert);
   __ push(rax);
   __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
   __ bind(&done_convert);
   __ push(rax);

   // 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.
   Label next, call_runtime;
   Register empty_fixed_array_value = r8;
   __ LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
   Register empty_descriptor_array_value = r9;
   __ LoadRoot(empty_descriptor_array_value,
               Heap::kEmptyDescriptorArrayRootIndex);
   __ movq(rcx, rax);
   __ bind(&next);

   // Check that there are no elements.  Register rcx contains the
   // current JS object we've reached through the prototype chain.
   __ cmpq(empty_fixed_array_value,
           FieldOperand(rcx, JSObject::kElementsOffset));
   __ j(not_equal, &call_runtime);

   // Check that instance descriptors are not empty so that we can
   // check for an enum cache.  Leave the map in rbx for the subsequent
   // prototype load.
   __ movq(rbx, FieldOperand(rcx, HeapObject::kMapOffset));
   __ movq(rdx, FieldOperand(rbx, Map::kInstanceDescriptorsOffset));
   __ cmpq(rdx, empty_descriptor_array_value);
   __ j(equal, &call_runtime);

   // Check that there is an enum cache in the non-empty instance
   // descriptors (rdx).  This is the case if the next enumeration
   // index field does not contain a smi.
   __ movq(rdx, FieldOperand(rdx, DescriptorArray::kEnumerationIndexOffset));
   __ JumpIfSmi(rdx, &call_runtime);

   // For all objects but the receiver, check that the cache is empty.
   NearLabel check_prototype;
   __ cmpq(rcx, rax);
   __ j(equal, &check_prototype);
   __ movq(rdx, FieldOperand(rdx, DescriptorArray::kEnumCacheBridgeCacheOffset));
   __ cmpq(rdx, empty_fixed_array_value);
   __ j(not_equal, &call_runtime);

   // Load the prototype from the map and loop if non-null.
   __ bind(&check_prototype);
   __ movq(rcx, FieldOperand(rbx, Map::kPrototypeOffset));
   __ cmpq(rcx, null_value);
   __ j(not_equal, &next);

   // The enum cache is valid.  Load the map of the object being
   // iterated over and use the cache for the iteration.
   NearLabel use_cache;
   __ movq(rax, FieldOperand(rax, HeapObject::kMapOffset));
   __ jmp(&use_cache);

   // 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.
   NearLabel 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);
   __ movq(rcx, FieldOperand(rax, Map::kInstanceDescriptorsOffset));
   __ movq(rcx, FieldOperand(rcx, DescriptorArray::kEnumerationIndexOffset));
   __ movq(rdx, FieldOperand(rcx, DescriptorArray::kEnumCacheBridgeCacheOffset));

   // Setup the four remaining stack slots.
   __ push(rax);  // Map.
   __ push(rdx);  // Enumeration cache.
   __ movq(rax, FieldOperand(rdx, FixedArray::kLengthOffset));
   __ push(rax);  // Enumeration cache length (as smi).
   __ Push(Smi::FromInt(0));  // Initial index.
   __ jmp(&loop);

   // We got a fixed array in register rax. Iterate through that.
   __ bind(&fixed_array);
   __ Push(Smi::FromInt(0));  // Map (0) - force slow check.
   __ push(rax);
   __ movq(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.
   __ bind(&loop);
   __ movq(rax, Operand(rsp, 0 * kPointerSize));  // Get the current index.
   __ cmpq(rax, Operand(rsp, 1 * kPointerSize));  // Compare to the array length.
   __ j(above_equal, loop_statement.break_target());

   // Get the current entry of the array into register rbx.
   __ movq(rbx, Operand(rsp, 2 * kPointerSize));
   SmiIndex index = masm()->SmiToIndex(rax, rax, kPointerSizeLog2);
   __ movq(rbx, FieldOperand(rbx,
                             index.reg,
                             index.scale,
                             FixedArray::kHeaderSize));

   // Get the expected map from the stack or a zero map in the
   // permanent slow case into register rdx.
   __ movq(rdx, Operand(rsp, 3 * kPointerSize));

   // Check if the expected map still matches that of the enumerable.
   // If not, we have to filter the key.
   NearLabel update_each;
   __ movq(rcx, Operand(rsp, 4 * kPointerSize));
   __ cmpq(rdx, FieldOperand(rcx, HeapObject::kMapOffset));
   __ j(equal, &update_each);

   // 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);
   __ SmiCompare(rax, Smi::FromInt(0));
   __ j(equal, loop_statement.continue_target());
   __ movq(rbx, rax);

   // Update the 'each' property or variable from the possibly filtered
   // entry in register rbx.
   __ bind(&update_each);
   __ movq(result_register(), rbx);
   // Perform the assignment as if via '='.
   { EffectContext context(this);
     EmitAssignment(stmt->each(), stmt->AssignmentId());
   }

   // 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_target());
   __ SmiAddConstant(Operand(rsp, 0 * kPointerSize), Smi::FromInt(1));

   EmitStackCheck(stmt);
   __ jmp(&loop);

   // Remove the pointers stored on the stack.
   __ bind(loop_statement.break_target());
   __ addq(rsp, Immediate(5 * kPointerSize));

   // Exit and decrement the loop depth.
   __ bind(&exit);
   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 &&
       scope()->is_function_scope() &&
       info->num_literals() == 0 &&
       !pretenure) {
     FastNewClosureStub stub;
     __ Push(info);
     __ CallStub(&stub);
   } else {
     __ push(rsi);
     __ Push(info);
     __ Push(pretenure ? Factory::true_value() : Factory::false_value());
     __ CallRuntime(Runtime::kNewClosure, 3);
   }
   context()->Plug(rax);
 }


 void FullCodeGenerator::VisitVariableProxy(VariableProxy* expr) {
   Comment cmnt(masm_, "[ VariableProxy");
   EmitVariableLoad(expr->var());
 }


 void FullCodeGenerator::EmitLoadGlobalSlotCheckExtensions(
     Slot* slot,
     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_eval()) {
         // Check that extension is NULL.
         __ cmpq(ContextOperand(context, Context::EXTENSION_INDEX),
                 Immediate(0));
         __ j(not_equal, slow);
       }
       // Load next context in chain.
       __ movq(temp, ContextOperand(context, Context::CLOSURE_INDEX));
       __ movq(temp, FieldOperand(temp, JSFunction::kContextOffset));
       // 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_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.
     NearLabel next, fast;
     if (!context.is(temp)) {
       __ movq(temp, context);
     }
     // Load map for comparison into register, outside loop.
     __ LoadRoot(kScratchRegister, Heap::kGlobalContextMapRootIndex);
     __ bind(&next);
     // Terminate at global context.
     __ cmpq(kScratchRegister, FieldOperand(temp, HeapObject::kMapOffset));
     __ j(equal, &fast);
     // Check that extension is NULL.
     __ cmpq(ContextOperand(temp, Context::EXTENSION_INDEX), Immediate(0));
     __ j(not_equal, slow);
     // Load next context in chain.
     __ movq(temp, ContextOperand(temp, Context::CLOSURE_INDEX));
     __ movq(temp, FieldOperand(temp, JSFunction::kContextOffset));
     __ jmp(&next);
     __ bind(&fast);
   }

   // All extension objects were empty and it is safe to use a global
   // load IC call.
   __ movq(rax, GlobalObjectOperand());
   __ Move(rcx, slot->var()->name());
   Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
   RelocInfo::Mode mode = (typeof_state == INSIDE_TYPEOF)
       ? RelocInfo::CODE_TARGET
       : RelocInfo::CODE_TARGET_CONTEXT;
   EmitCallIC(ic, mode);
 }


 MemOperand FullCodeGenerator::ContextSlotOperandCheckExtensions(
     Slot* slot,
     Label* slow) {
   ASSERT(slot->type() == Slot::CONTEXT);
   Register context = rsi;
   Register temp = rbx;

   for (Scope* s = scope(); s != slot->var()->scope(); s = s->outer_scope()) {
     if (s->num_heap_slots() > 0) {
       if (s->calls_eval()) {
         // Check that extension is NULL.
         __ cmpq(ContextOperand(context, Context::EXTENSION_INDEX),
                 Immediate(0));
         __ j(not_equal, slow);
       }
       __ movq(temp, ContextOperand(context, Context::CLOSURE_INDEX));
       __ movq(temp, FieldOperand(temp, JSFunction::kContextOffset));
       // Walk the rest of the chain without clobbering rsi.
       context = temp;
     }
   }
   // Check that last extension is NULL.
   __ cmpq(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, slot->index());
 }


 void FullCodeGenerator::EmitDynamicLoadFromSlotFastCase(
     Slot* slot,
     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.
   if (slot->var()->mode() == Variable::DYNAMIC_GLOBAL) {
     EmitLoadGlobalSlotCheckExtensions(slot, typeof_state, slow);
     __ jmp(done);
   } else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
     Slot* potential_slot = slot->var()->local_if_not_shadowed()->AsSlot();
     Expression* rewrite = slot->var()->local_if_not_shadowed()->rewrite();
     if (potential_slot != NULL) {
       // Generate fast case for locals that rewrite to slots.
       __ movq(rax,
               ContextSlotOperandCheckExtensions(potential_slot, slow));
       if (potential_slot->var()->mode() == Variable::CONST) {
         __ CompareRoot(rax, Heap::kTheHoleValueRootIndex);
         __ j(not_equal, done);
         __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
       }
       __ jmp(done);
     } else if (rewrite != NULL) {
       // Generate fast case for calls of an argument function.
       Property* property = rewrite->AsProperty();
       if (property != NULL) {
         VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
         Literal* key_literal = property->key()->AsLiteral();
         if (obj_proxy != NULL &&
             key_literal != NULL &&
             obj_proxy->IsArguments() &&
             key_literal->handle()->IsSmi()) {
           // Load arguments object if there are no eval-introduced
           // variables. Then load the argument from the arguments
           // object using keyed load.
           __ movq(rdx,
                   ContextSlotOperandCheckExtensions(obj_proxy->var()->AsSlot(),
                                                     slow));
           __ Move(rax, key_literal->handle());
           Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
           EmitCallIC(ic, RelocInfo::CODE_TARGET);
           __ jmp(done);
         }
       }
     }
   }
 }


 void FullCodeGenerator::EmitVariableLoad(Variable* var) {
   // Four cases: non-this global variables, lookup slots, all other
   // types of slots, and parameters that rewrite to explicit property
   // accesses on the arguments object.
   Slot* slot = var->AsSlot();
   Property* property = var->AsProperty();

   if (var->is_global() && !var->is_this()) {
     Comment cmnt(masm_, "Global variable");
     // Use inline caching. Variable name is passed in rcx and the global
     // object on the stack.
     __ Move(rcx, var->name());
     __ movq(rax, GlobalObjectOperand());
     Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
     EmitCallIC(ic, RelocInfo::CODE_TARGET_CONTEXT);
     context()->Plug(rax);

   } else if (slot != NULL && slot->type() == Slot::LOOKUP) {
     Label done, slow;

     // Generate code for loading from variables potentially shadowed
     // by eval-introduced variables.
     EmitDynamicLoadFromSlotFastCase(slot, NOT_INSIDE_TYPEOF, &slow, &done);

     __ bind(&slow);
     Comment cmnt(masm_, "Lookup slot");
     __ push(rsi);  // Context.
     __ Push(var->name());
     __ CallRuntime(Runtime::kLoadContextSlot, 2);
     __ bind(&done);

     context()->Plug(rax);

   } else if (slot != NULL) {
     Comment cmnt(masm_, (slot->type() == Slot::CONTEXT)
                             ? "Context slot"
                             : "Stack slot");
     if (var->mode() == Variable::CONST) {
       // Constants may be the hole value if they have not been initialized.
       // Unhole them.
       NearLabel done;
       MemOperand slot_operand = EmitSlotSearch(slot, rax);
       __ movq(rax, slot_operand);
       __ CompareRoot(rax, Heap::kTheHoleValueRootIndex);
       __ j(not_equal, &done);
       __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
       __ bind(&done);
       context()->Plug(rax);
     } else {
       context()->Plug(slot);
     }

   } else {
     Comment cmnt(masm_, "Rewritten parameter");
     ASSERT_NOT_NULL(property);
     // Rewritten parameter accesses are of the form "slot[literal]".

     // Assert that the object is in a slot.
     Variable* object_var = property->obj()->AsVariableProxy()->AsVariable();
     ASSERT_NOT_NULL(object_var);
     Slot* object_slot = object_var->AsSlot();
     ASSERT_NOT_NULL(object_slot);

     // Load the object.
     MemOperand object_loc = EmitSlotSearch(object_slot, rax);
     __ movq(rdx, object_loc);

     // Assert that the key is a smi.
     Literal* key_literal = property->key()->AsLiteral();
     ASSERT_NOT_NULL(key_literal);
     ASSERT(key_literal->handle()->IsSmi());

     // Load the key.
     __ Move(rax, key_literal->handle());

     // Do a keyed property load.
     Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
     EmitCallIC(ic, RelocInfo::CODE_TARGET);
     context()->Plug(rax);
   }
 }


 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.
   __ movq(rdi, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   __ movq(rcx, FieldOperand(rdi, JSFunction::kLiteralsOffset));
   int literal_offset =
       FixedArray::kHeaderSize + expr->literal_index() * kPointerSize;
   __ movq(rbx, FieldOperand(rcx, literal_offset));
   __ CompareRoot(rbx, Heap::kUndefinedValueRootIndex);
   __ j(not_equal, &materialized);

   // 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);
   __ movq(rbx, rax);

   __ bind(&materialized);
   int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
   Label allocated, runtime_allocate;
   __ AllocateInNewSpace(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) {
     __ movq(rdx, FieldOperand(rbx, i));
     __ movq(rcx, FieldOperand(rbx, i + kPointerSize));
     __ movq(FieldOperand(rax, i), rdx);
     __ movq(FieldOperand(rax, i + kPointerSize), rcx);
   }
   if ((size % (2 * kPointerSize)) != 0) {
     __ movq(rdx, FieldOperand(rbx, size - kPointerSize));
     __ movq(FieldOperand(rax, size - kPointerSize), rdx);
   }
   context()->Plug(rax);
 }


 void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
   Comment cmnt(masm_, "[ ObjectLiteral");
   __ movq(rdi, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   __ push(FieldOperand(rdi, JSFunction::kLiteralsOffset));
   __ Push(Smi::FromInt(expr->literal_index()));
   __ Push(expr->constant_properties());
   __ Push(Smi::FromInt(expr->fast_elements() ? 1 : 0));
   if (expr->depth() > 1) {
     __ CallRuntime(Runtime::kCreateObjectLiteral, 4);
   } else {
     __ CallRuntime(Runtime::kCreateObjectLiteralShallow, 4);
   }

   // 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();

   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:
         ASSERT(!CompileTimeValue::IsCompileTimeValue(value));
         // Fall through.
       case ObjectLiteral::Property::COMPUTED:
         if (key->handle()->IsSymbol()) {
           VisitForAccumulatorValue(value);
           __ Move(rcx, key->handle());
           __ movq(rdx, Operand(rsp, 0));
           if (property->emit_store()) {
             Handle<Code> ic(Builtins::builtin(Builtins::StoreIC_Initialize));
             EmitCallIC(ic, RelocInfo::CODE_TARGET);
             PrepareForBailoutForId(key->id(), NO_REGISTERS);
           }
           break;
         }
         // Fall through.
       case ObjectLiteral::Property::PROTOTYPE:
         __ push(Operand(rsp, 0));  // Duplicate receiver.
         VisitForStackValue(key);
         VisitForStackValue(value);
         if (property->emit_store()) {
           __ Push(Smi::FromInt(NONE));    // PropertyAttributes
           __ CallRuntime(Runtime::kSetProperty, 4);
         } else {
           __ Drop(3);
         }
         break;
       case ObjectLiteral::Property::SETTER:
       case ObjectLiteral::Property::GETTER:
         __ push(Operand(rsp, 0));  // Duplicate receiver.
         VisitForStackValue(key);
         __ Push(property->kind() == ObjectLiteral::Property::SETTER ?
                 Smi::FromInt(1) :
                 Smi::FromInt(0));
         VisitForStackValue(value);
         __ CallRuntime(Runtime::kDefineAccessor, 4);
         break;
     }
   }

   if (result_saved) {
     context()->PlugTOS();
   } else {
     context()->Plug(rax);
   }
 }


 void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   Comment cmnt(masm_, "[ ArrayLiteral");

   ZoneList<Expression*>* subexprs = expr->values();
   int length = subexprs->length();

   __ movq(rbx, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   __ push(FieldOperand(rbx, JSFunction::kLiteralsOffset));
   __ Push(Smi::FromInt(expr->literal_index()));
   __ Push(expr->constant_elements());
   if (expr->constant_elements()->map() == Heap::fixed_cow_array_map()) {
     FastCloneShallowArrayStub stub(
         FastCloneShallowArrayStub::COPY_ON_WRITE_ELEMENTS, length);
     __ CallStub(&stub);
     __ IncrementCounter(&Counters::cow_arrays_created_stub, 1);
   } else if (expr->depth() > 1) {
     __ CallRuntime(Runtime::kCreateArrayLiteral, 3);
   } else if (length > FastCloneShallowArrayStub::kMaximumClonedLength) {
     __ CallRuntime(Runtime::kCreateArrayLiteralShallow, 3);
   } else {
     FastCloneShallowArrayStub stub(
         FastCloneShallowArrayStub::CLONE_ELEMENTS, length);
     __ 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 (subexpr->AsLiteral() != NULL ||
         CompileTimeValue::IsCompileTimeValue(subexpr)) {
       continue;
     }

     if (!result_saved) {
       __ push(rax);
       result_saved = true;
     }
     VisitForAccumulatorValue(subexpr);

     // Store the subexpression value in the array's elements.
     __ movq(rbx, Operand(rsp, 0));  // Copy of array literal.
     __ movq(rbx, FieldOperand(rbx, JSObject::kElementsOffset));
     int offset = FixedArray::kHeaderSize + (i * kPointerSize);
     __ movq(FieldOperand(rbx, offset), result_register());

     // Update the write barrier for the array store.
     __ RecordWrite(rbx, offset, result_register(), rcx);

     PrepareForBailoutForId(expr->GetIdForElement(i), NO_REGISTERS);
   }

   if (result_saved) {
     context()->PlugTOS();
   } else {
     context()->Plug(rax);
   }
 }


 void FullCodeGenerator::VisitAssignment(Assignment* expr) {
   Comment cmnt(masm_, "[ Assignment");
   // Invalid left-hand sides are rewritten to have a 'throw ReferenceError'
   // on the left-hand side.
   if (!expr->target()->IsValidLeftHandSide()) {
     VisitForEffect(expr->target());
     return;
   }

   // Left-hand side can only be a property, a global or a (parameter or local)
   // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* property = expr->target()->AsProperty();
   if (property != NULL) {
     assign_type = (property->key()->IsPropertyName())
         ? NAMED_PROPERTY
         : KEYED_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 accumulator.
         VisitForAccumulatorValue(property->obj());
         __ push(result_register());
       } else {
         VisitForStackValue(property->obj());
       }
       break;
     case KEYED_PROPERTY: {
       if (expr->is_compound()) {
         if (property->is_arguments_access()) {
           VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
           MemOperand slot_operand =
               EmitSlotSearch(obj_proxy->var()->AsSlot(), rcx);
           __ push(slot_operand);
           __ Move(rax, property->key()->AsLiteral()->handle());
         } else {
           VisitForStackValue(property->obj());
           VisitForAccumulatorValue(property->key());
         }
         __ movq(rdx, Operand(rsp, 0));
         __ push(rax);
       } else {
         if (property->is_arguments_access()) {
           VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
           MemOperand slot_operand =
               EmitSlotSearch(obj_proxy->var()->AsSlot(), rcx);
           __ push(slot_operand);
           __ Push(property->key()->AsLiteral()->handle());
         } else {
           VisitForStackValue(property->obj());
           VisitForStackValue(property->key());
         }
       }
       break;
     }
   }

   if (expr->is_compound()) {
     { AccumulatorValueContext context(this);
       switch (assign_type) {
         case VARIABLE:
           EmitVariableLoad(expr->target()->AsVariableProxy()->var());
           break;
         case NAMED_PROPERTY:
           EmitNamedPropertyLoad(property);
           break;
         case KEYED_PROPERTY:
           EmitKeyedPropertyLoad(property);
           break;
       }
     }

     // For property compound assignments we need another deoptimization
     // point after the property load.
     if (property != NULL) {
       PrepareForBailoutForId(expr->CompoundLoadId(), TOS_REG);
     }

     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,
                             op,
                             mode,
                             expr->target(),
                             expr->value());
     } else {
       EmitBinaryOp(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 KEYED_PROPERTY:
       EmitKeyedPropertyAssignment(expr);
       break;
   }
 }


 void FullCodeGenerator::EmitNamedPropertyLoad(Property* prop) {
   SetSourcePosition(prop->position());
   Literal* key = prop->key()->AsLiteral();
   __ Move(rcx, key->handle());
   Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
   EmitCallIC(ic, RelocInfo::CODE_TARGET);
 }


 void FullCodeGenerator::EmitKeyedPropertyLoad(Property* prop) {
   SetSourcePosition(prop->position());
   Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
   EmitCallIC(ic, RelocInfo::CODE_TARGET);
 }


 void FullCodeGenerator::EmitInlineSmiBinaryOp(Expression* 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.
   NearLabel done, stub_call, smi_case;
   __ pop(rdx);
   __ movq(rcx, rax);
   __ or_(rax, rdx);
   JumpPatchSite patch_site(masm_);
   patch_site.EmitJumpIfSmi(rax, &smi_case);

   __ bind(&stub_call);
   __ movq(rax, rcx);
   TypeRecordingBinaryOpStub stub(op, mode);
   EmitCallIC(stub.GetCode(), &patch_site);
   __ jmp(&done);

   __ bind(&smi_case);
   switch (op) {
     case Token::SAR:
       __ SmiShiftArithmeticRight(rax, rdx, rcx);
       break;
     case Token::SHL:
       __ SmiShiftLeft(rax, rdx, rcx);
       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(Token::Value op,
                                      OverwriteMode mode) {
   __ pop(rdx);
   TypeRecordingBinaryOpStub stub(op, mode);
   EmitCallIC(stub.GetCode(), NULL);  // NULL signals no inlined smi code.
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitAssignment(Expression* expr, int bailout_ast_id) {
   // Invalid left-hand sides are rewritten to have a 'throw
   // ReferenceError' on the left-hand side.
   if (!expr->IsValidLeftHandSide()) {
     VisitForEffect(expr);
     return;
   }

   // Left-hand side can only be a property, a global or a (parameter or local)
   // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* prop = expr->AsProperty();
   if (prop != NULL) {
     assign_type = (prop->key()->IsPropertyName())
         ? NAMED_PROPERTY
         : KEYED_PROPERTY;
   }

   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());
       __ movq(rdx, rax);
       __ pop(rax);  // Restore value.
       __ Move(rcx, prop->key()->AsLiteral()->handle());
       Handle<Code> ic(Builtins::builtin(
           is_strict() ? Builtins::StoreIC_Initialize_Strict
                       : Builtins::StoreIC_Initialize));
       EmitCallIC(ic, RelocInfo::CODE_TARGET);
       break;
     }
     case KEYED_PROPERTY: {
       __ push(rax);  // Preserve value.
       if (prop->is_synthetic()) {
         ASSERT(prop->obj()->AsVariableProxy() != NULL);
         ASSERT(prop->key()->AsLiteral() != NULL);
         { AccumulatorValueContext for_object(this);
           EmitVariableLoad(prop->obj()->AsVariableProxy()->var());
         }
         __ movq(rdx, rax);
         __ Move(rcx, prop->key()->AsLiteral()->handle());
       } else {
         VisitForStackValue(prop->obj());
         VisitForAccumulatorValue(prop->key());
         __ movq(rcx, rax);
         __ pop(rdx);
       }
       __ pop(rax);  // Restore value.
       Handle<Code> ic(Builtins::builtin(
           is_strict() ? Builtins::KeyedStoreIC_Initialize_Strict
                       : Builtins::KeyedStoreIC_Initialize));
       EmitCallIC(ic, RelocInfo::CODE_TARGET);
       break;
     }
   }
   PrepareForBailoutForId(bailout_ast_id, TOS_REG);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitVariableAssignment(Variable* var,
                                                Token::Value op) {
   // Left-hand sides that rewrite to explicit property accesses do not reach
   // here.
   ASSERT(var != NULL);
   ASSERT(var->is_global() || var->AsSlot() != NULL);

   if (var->is_global()) {
     ASSERT(!var->is_this());
     // Assignment to a global variable.  Use inline caching for the
     // assignment.  Right-hand-side value is passed in rax, variable name in
     // rcx, and the global object on the stack.
     __ Move(rcx, var->name());
     __ movq(rdx, GlobalObjectOperand());
     Handle<Code> ic(Builtins::builtin(is_strict()
         ? Builtins::StoreIC_Initialize_Strict
         : Builtins::StoreIC_Initialize));
     EmitCallIC(ic, RelocInfo::CODE_TARGET_CONTEXT);

   } else if (op == Token::INIT_CONST) {
     // Like var declarations, const declarations are hoisted to function
     // scope.  However, unlike var initializers, const initializers are able
     // to drill a hole to that function context, even from inside a 'with'
     // context.  We thus bypass the normal static scope lookup.
     Slot* slot = var->AsSlot();
     Label skip;
     switch (slot->type()) {
       case Slot::PARAMETER:
         // No const parameters.
         UNREACHABLE();
         break;
       case Slot::LOCAL:
         __ movq(rdx, Operand(rbp, SlotOffset(slot)));
         __ CompareRoot(rdx, Heap::kTheHoleValueRootIndex);
         __ j(not_equal, &skip);
         __ movq(Operand(rbp, SlotOffset(slot)), rax);
         break;
       case Slot::CONTEXT: {
         __ movq(rcx, ContextOperand(rsi, Context::FCONTEXT_INDEX));
         __ movq(rdx, ContextOperand(rcx, slot->index()));
         __ CompareRoot(rdx, Heap::kTheHoleValueRootIndex);
         __ j(not_equal, &skip);
         __ movq(ContextOperand(rcx, slot->index()), rax);
         int offset = Context::SlotOffset(slot->index());
         __ movq(rdx, rax);  // Preserve the stored value in eax.
         __ RecordWrite(rcx, offset, rdx, rbx);
         break;
       }
       case Slot::LOOKUP:
         __ push(rax);
         __ push(rsi);
         __ Push(var->name());
         __ CallRuntime(Runtime::kInitializeConstContextSlot, 3);
         break;
     }
     __ bind(&skip);

   } else if (var->mode() != Variable::CONST) {
     // Perform the assignment for non-const variables.  Const assignments
     // are simply skipped.
     Slot* slot = var->AsSlot();
     switch (slot->type()) {
       case Slot::PARAMETER:
       case Slot::LOCAL:
         // Perform the assignment.
         __ movq(Operand(rbp, SlotOffset(slot)), rax);
         break;

       case Slot::CONTEXT: {
         MemOperand target = EmitSlotSearch(slot, rcx);
         // Perform the assignment and issue the write barrier.
         __ movq(target, rax);
         // The value of the assignment is in rax.  RecordWrite clobbers its
         // register arguments.
         __ movq(rdx, rax);
         int offset = Context::SlotOffset(slot->index());
         __ RecordWrite(rcx, offset, rdx, rbx);
         break;
       }

       case Slot::LOOKUP:
         // Call the runtime for the assignment.
         __ push(rax);  // Value.
         __ push(rsi);  // Context.
         __ Push(var->name());
         __ Push(Smi::FromInt(strict_mode_flag()));
         __ CallRuntime(Runtime::kStoreContextSlot, 4);
         break;
     }
   }
 }


 void FullCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) {
   // Assignment to a property, using a named store IC.
   Property* prop = expr->target()->AsProperty();
   ASSERT(prop != NULL);
   ASSERT(prop->key()->AsLiteral() != NULL);

   // If the assignment starts a block of assignments to the same object,
   // change to slow case to avoid the quadratic behavior of repeatedly
   // adding fast properties.
   if (expr->starts_initialization_block()) {
     __ push(result_register());
     __ push(Operand(rsp, kPointerSize));  // Receiver is now under value.
     __ CallRuntime(Runtime::kToSlowProperties, 1);
     __ pop(result_register());
   }

   // Record source code position before IC call.
   SetSourcePosition(expr->position());
   __ Move(rcx, prop->key()->AsLiteral()->handle());
   if (expr->ends_initialization_block()) {
     __ movq(rdx, Operand(rsp, 0));
   } else {
     __ pop(rdx);
   }
   Handle<Code> ic(Builtins::builtin(
       is_strict() ? Builtins::StoreIC_Initialize_Strict
                   : Builtins::StoreIC_Initialize));
   EmitCallIC(ic, RelocInfo::CODE_TARGET);

   // If the assignment ends an initialization block, revert to fast case.
   if (expr->ends_initialization_block()) {
     __ push(rax);  // Result of assignment, saved even if not needed.
     __ push(Operand(rsp, kPointerSize));  // Receiver is under value.
     __ CallRuntime(Runtime::kToFastProperties, 1);
     __ pop(rax);
     __ Drop(1);
   }
   PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) {
   // Assignment to a property, using a keyed store IC.

   // If the assignment starts a block of assignments to the same object,
   // change to slow case to avoid the quadratic behavior of repeatedly
   // adding fast properties.
   if (expr->starts_initialization_block()) {
     __ push(result_register());
     // Receiver is now under the key and value.
     __ push(Operand(rsp, 2 * kPointerSize));
     __ CallRuntime(Runtime::kToSlowProperties, 1);
     __ pop(result_register());
   }

   __ pop(rcx);
   if (expr->ends_initialization_block()) {
     __ movq(rdx, Operand(rsp, 0));  // Leave receiver on the stack for later.
   } else {
     __ pop(rdx);
   }
   // Record source code position before IC call.
   SetSourcePosition(expr->position());
   Handle<Code> ic(Builtins::builtin(
       is_strict() ? Builtins::KeyedStoreIC_Initialize_Strict
                   : Builtins::KeyedStoreIC_Initialize));
   EmitCallIC(ic, RelocInfo::CODE_TARGET);

   // If the assignment ends an initialization block, revert to fast case.
   if (expr->ends_initialization_block()) {
     __ pop(rdx);
     __ push(rax);  // Result of assignment, saved even if not needed.
     __ push(rdx);
     __ CallRuntime(Runtime::kToFastProperties, 1);
     __ pop(rax);
   }

   PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   context()->Plug(rax);
 }


 void FullCodeGenerator::VisitProperty(Property* expr) {
   Comment cmnt(masm_, "[ Property");
   Expression* key = expr->key();

   if (key->IsPropertyName()) {
     VisitForAccumulatorValue(expr->obj());
     EmitNamedPropertyLoad(expr);
     context()->Plug(rax);
   } else {
     VisitForStackValue(expr->obj());
     VisitForAccumulatorValue(expr->key());
     __ pop(rdx);
     EmitKeyedPropertyLoad(expr);
     context()->Plug(rax);
   }
 }


 void FullCodeGenerator::EmitCallWithIC(Call* expr,
                                        Handle<Object> name,
                                        RelocInfo::Mode mode) {
   // Code common for calls using the IC.
   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));
     }
     __ Move(rcx, name);
   }
   // Record source position for debugger.
   SetSourcePosition(expr->position());
   // Call the IC initialization code.
   InLoopFlag in_loop = (loop_depth() > 0) ? IN_LOOP : NOT_IN_LOOP;
   Handle<Code> ic = StubCache::ComputeCallInitialize(arg_count, in_loop);
   EmitCallIC(ic, mode);
   RecordJSReturnSite(expr);
   // Restore context register.
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitKeyedCallWithIC(Call* expr,
                                             Expression* key,
                                             RelocInfo::Mode mode) {
   // Load the key.
   VisitForAccumulatorValue(key);

   // Swap the name of the function and the receiver on the stack to follow
   // the calling convention for call ICs.
   __ pop(rcx);
   __ push(rax);
   __ push(rcx);

   // 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 for debugger.
   SetSourcePosition(expr->position());
   // Call the IC initialization code.
   InLoopFlag in_loop = (loop_depth() > 0) ? IN_LOOP : NOT_IN_LOOP;
   Handle<Code> ic = StubCache::ComputeKeyedCallInitialize(arg_count, in_loop);
   __ movq(rcx, Operand(rsp, (arg_count + 1) * kPointerSize));  // Key.
   EmitCallIC(ic, mode);
   RecordJSReturnSite(expr);
   // Restore context register.
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   context()->DropAndPlug(1, rax);  // Drop the key still on the stack.
 }


 void FullCodeGenerator::EmitCallWithStub(Call* expr) {
   // Code common for calls using the call stub.
   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 for debugger.
   SetSourcePosition(expr->position());
   InLoopFlag in_loop = (loop_depth() > 0) ? IN_LOOP : NOT_IN_LOOP;
   CallFunctionStub stub(arg_count, in_loop, RECEIVER_MIGHT_BE_VALUE);
   __ CallStub(&stub);
   RecordJSReturnSite(expr);
   // Restore context register.
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   // Discard the function left on TOS.
   context()->DropAndPlug(1, rax);
 }


 void FullCodeGenerator::EmitResolvePossiblyDirectEval(ResolveEvalFlag flag,
                                                       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.
   __ push(Operand(rbp, (2 + scope()->num_parameters()) * kPointerSize));

   // Push the strict mode flag.
   __ Push(Smi::FromInt(strict_mode_flag()));

   __ CallRuntime(flag == SKIP_CONTEXT_LOOKUP
                  ? Runtime::kResolvePossiblyDirectEvalNoLookup
                  : Runtime::kResolvePossiblyDirectEval, 4);
 }


 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* fun = expr->expression();
   Variable* var = fun->AsVariableProxy()->AsVariable();

   if (var != NULL && var->is_possibly_eval()) {
     // In a call to eval, we first call %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(fun);
       __ PushRoot(Heap::kUndefinedValueRootIndex);  // Reserved receiver slot.

       // Push the arguments.
       for (int i = 0; i < arg_count; i++) {
         VisitForStackValue(args->at(i));
       }

       // If we know that eval can only be shadowed by eval-introduced
       // variables we attempt to load the global eval function directly
       // in generated code. If we succeed, there is no need to perform a
       // context lookup in the runtime system.
       Label done;
       if (var->AsSlot() != NULL && var->mode() == Variable::DYNAMIC_GLOBAL) {
         Label slow;
         EmitLoadGlobalSlotCheckExtensions(var->AsSlot(),
                                           NOT_INSIDE_TYPEOF,
                                           &slow);
         // Push the function and resolve eval.
         __ push(rax);
         EmitResolvePossiblyDirectEval(SKIP_CONTEXT_LOOKUP, arg_count);
         __ jmp(&done);
         __ bind(&slow);
       }

       // Push copy of the function (found below the arguments) and
       // resolve eval.
       __ push(Operand(rsp, (arg_count + 1) * kPointerSize));
       EmitResolvePossiblyDirectEval(PERFORM_CONTEXT_LOOKUP, arg_count);
       if (done.is_linked()) {
         __ bind(&done);
       }

       // The runtime call returns a pair of values in rax (function) and
       // rdx (receiver). Touch up the stack with the right values.
       __ movq(Operand(rsp, (arg_count + 0) * kPointerSize), rdx);
       __ movq(Operand(rsp, (arg_count + 1) * kPointerSize), rax);
     }
     // Record source position for debugger.
     SetSourcePosition(expr->position());
     InLoopFlag in_loop = (loop_depth() > 0) ? IN_LOOP : NOT_IN_LOOP;
     CallFunctionStub stub(arg_count, in_loop, RECEIVER_MIGHT_BE_VALUE);
     __ CallStub(&stub);
     RecordJSReturnSite(expr);
     // Restore context register.
     __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
     context()->DropAndPlug(1, rax);
   } else if (var != NULL && !var->is_this() && var->is_global()) {
     // Call to a global variable.
     // Push global object as receiver for the call IC lookup.
     __ push(GlobalObjectOperand());
     EmitCallWithIC(expr, var->name(), RelocInfo::CODE_TARGET_CONTEXT);
   } else if (var != NULL && var->AsSlot() != NULL &&
              var->AsSlot()->type() == Slot::LOOKUP) {
     // Call to a lookup slot (dynamically introduced variable).
     Label slow, done;

     { PreservePositionScope scope(masm()->positions_recorder());
       // Generate code for loading from variables potentially shadowed
       // by eval-introduced variables.
       EmitDynamicLoadFromSlotFastCase(var->AsSlot(),
                                       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(var->name());
     __ CallRuntime(Runtime::kLoadContextSlot, 2);
     __ push(rax);  // Function.
     __ push(rdx);  // Receiver.

     // 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()) {
       NearLabel call;
       __ jmp(&call);
       __ bind(&done);
       // Push function.
       __ push(rax);
       // Push global receiver.
         __ movq(rbx, GlobalObjectOperand());
         __ push(FieldOperand(rbx, GlobalObject::kGlobalReceiverOffset));
         __ bind(&call);
     }

     EmitCallWithStub(expr);
   } else if (fun->AsProperty() != NULL) {
     // Call to an object property.
     Property* prop = fun->AsProperty();
     Literal* key = prop->key()->AsLiteral();
     if (key != NULL && key->handle()->IsSymbol()) {
       // Call to a named property, use call IC.
       { PreservePositionScope scope(masm()->positions_recorder());
         VisitForStackValue(prop->obj());
       }
       EmitCallWithIC(expr, key->handle(), RelocInfo::CODE_TARGET);
     } else {
       // Call to a keyed property.
       // For a synthetic property use keyed load IC followed by function call,
       // for a regular property use keyed EmitCallIC.
       if (prop->is_synthetic()) {
         // Do not visit the object and key subexpressions (they are shared
         // by all occurrences of the same rewritten parameter).
         ASSERT(prop->obj()->AsVariableProxy() != NULL);
         ASSERT(prop->obj()->AsVariableProxy()->var()->AsSlot() != NULL);
         Slot* slot = prop->obj()->AsVariableProxy()->var()->AsSlot();
         MemOperand operand = EmitSlotSearch(slot, rdx);
         __ movq(rdx, operand);

         ASSERT(prop->key()->AsLiteral() != NULL);
         ASSERT(prop->key()->AsLiteral()->handle()->IsSmi());
         __ Move(rax, prop->key()->AsLiteral()->handle());

         // Record source code position for IC call.
         SetSourcePosition(prop->position());

         Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
         EmitCallIC(ic, RelocInfo::CODE_TARGET);
         // Push result (function).
         __ push(rax);
         // Push Global receiver.
         __ movq(rcx, GlobalObjectOperand());
         __ push(FieldOperand(rcx, GlobalObject::kGlobalReceiverOffset));
         EmitCallWithStub(expr);
       } else {
         { PreservePositionScope scope(masm()->positions_recorder());
           VisitForStackValue(prop->obj());
         }
         EmitKeyedCallWithIC(expr, prop->key(), RelocInfo::CODE_TARGET);
       }
     }
   } else {
     // Call to some other expression.  If the expression is an anonymous
     // function literal not called in a loop, mark it as one that should
     // also use the full code generator.
     FunctionLiteral* lit = fun->AsFunctionLiteral();
     if (lit != NULL &&
         lit->name()->Equals(Heap::empty_string()) &&
         loop_depth() == 0) {
       lit->set_try_full_codegen(true);
     }
     { PreservePositionScope scope(masm()->positions_recorder());
       VisitForStackValue(fun);
     }
     // Load global receiver object.
     __ movq(rbx, GlobalObjectOperand());
     __ push(FieldOperand(rbx, GlobalObject::kGlobalReceiverOffset));
     // Emit function call.
     EmitCallWithStub(expr);
   }

 #ifdef DEBUG
   // RecordJSReturnSite should have been called.
   ASSERT(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);
   __ movq(rdi, Operand(rsp, arg_count * kPointerSize));

   Handle<Code> construct_builtin(Builtins::builtin(Builtins::JSConstructCall));
   __ Call(construct_builtin, RelocInfo::CONSTRUCT_CALL);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitIsSmi(ZoneList<Expression*>* args) {
   ASSERT(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(TOS_REG, true, if_true, if_false);
   __ JumpIfSmi(rax, if_true);
   __ jmp(if_false);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitIsNonNegativeSmi(ZoneList<Expression*>* args) {
   ASSERT(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(TOS_REG, 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(ZoneList<Expression*>* args) {
   ASSERT(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);
   __ movq(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);
   __ movzxbq(rbx, FieldOperand(rbx, Map::kInstanceTypeOffset));
   __ cmpq(rbx, Immediate(FIRST_JS_OBJECT_TYPE));
   __ j(below, if_false);
   __ cmpq(rbx, Immediate(LAST_JS_OBJECT_TYPE));
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
   Split(below_equal, if_true, if_false, fall_through);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitIsSpecObject(ZoneList<Expression*>* args) {
   ASSERT(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_JS_OBJECT_TYPE, rbx);
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
   Split(above_equal, if_true, if_false, fall_through);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitIsUndetectableObject(ZoneList<Expression*>* args) {
   ASSERT(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);
   __ movq(rbx, FieldOperand(rax, HeapObject::kMapOffset));
   __ testb(FieldOperand(rbx, Map::kBitFieldOffset),
            Immediate(1 << Map::kIsUndetectable));
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
   Split(not_zero, if_true, if_false, fall_through);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitIsStringWrapperSafeForDefaultValueOf(
     ZoneList<Expression*>* args) {
   ASSERT(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);

   // Just indicate false, as %_IsStringWrapperSafeForDefaultValueOf() is only
   // used in a few functions in runtime.js which should not normally be hit by
   // this compiler.
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
   __ jmp(if_false);
   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitIsFunction(ZoneList<Expression*>* args) {
   ASSERT(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(TOS_REG, true, if_true, if_false);
   Split(equal, if_true, if_false, fall_through);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitIsArray(ZoneList<Expression*>* args) {
   ASSERT(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(TOS_REG, true, if_true, if_false);
   Split(equal, if_true, if_false, fall_through);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitIsRegExp(ZoneList<Expression*>* args) {
   ASSERT(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(TOS_REG, true, if_true, if_false);
   Split(equal, if_true, if_false, fall_through);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitIsConstructCall(ZoneList<Expression*>* args) {
   ASSERT(args->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.
   __ movq(rax, Operand(rbp, StandardFrameConstants::kCallerFPOffset));

   // Skip the arguments adaptor frame if it exists.
   Label check_frame_marker;
   __ SmiCompare(Operand(rax, StandardFrameConstants::kContextOffset),
                 Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
   __ j(not_equal, &check_frame_marker);
   __ movq(rax, Operand(rax, StandardFrameConstants::kCallerFPOffset));

   // Check the marker in the calling frame.
   __ bind(&check_frame_marker);
   __ SmiCompare(Operand(rax, StandardFrameConstants::kMarkerOffset),
                 Smi::FromInt(StackFrame::CONSTRUCT));
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
   Split(equal, if_true, if_false, fall_through);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitObjectEquals(ZoneList<Expression*>* args) {
   ASSERT(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);
   __ cmpq(rax, rbx);
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
   Split(equal, if_true, if_false, fall_through);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitArguments(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 1);

   // ArgumentsAccessStub expects the key in rdx and the formal
   // parameter count in rax.
   VisitForAccumulatorValue(args->at(0));
   __ movq(rdx, rax);
   __ Move(rax, Smi::FromInt(scope()->num_parameters()));
   ArgumentsAccessStub stub(ArgumentsAccessStub::READ_ELEMENT);
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitArgumentsLength(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 0);

   NearLabel exit;
   // Get the number of formal parameters.
   __ Move(rax, Smi::FromInt(scope()->num_parameters()));

   // Check if the calling frame is an arguments adaptor frame.
   __ movq(rbx, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
   __ SmiCompare(Operand(rbx, StandardFrameConstants::kContextOffset),
                 Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
   __ j(not_equal, &exit);

   // Arguments adaptor case: Read the arguments length from the
   // adaptor frame.
   __ movq(rax, Operand(rbx, ArgumentsAdaptorFrameConstants::kLengthOffset));

   __ bind(&exit);
   if (FLAG_debug_code) __ AbortIfNotSmi(rax);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitClassOf(ZoneList<Expression*>* args) {
   ASSERT(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.
   __ CmpObjectType(rax, FIRST_JS_OBJECT_TYPE, rax);  // Map is now in rax.
   __ j(below, &null);

   // As long as JS_FUNCTION_TYPE is the last instance type and it is
   // right after LAST_JS_OBJECT_TYPE, we can avoid checking for
   // LAST_JS_OBJECT_TYPE.
   ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
   ASSERT(JS_FUNCTION_TYPE == LAST_JS_OBJECT_TYPE + 1);
   __ CmpInstanceType(rax, JS_FUNCTION_TYPE);
   __ j(equal, &function);

   // Check if the constructor in the map is a function.
   __ movq(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.
   __ movq(rax, FieldOperand(rax, JSFunction::kSharedFunctionInfoOffset));
   __ movq(rax, FieldOperand(rax, SharedFunctionInfo::kInstanceClassNameOffset));
   __ jmp(&done);

   // Functions have class 'Function'.
   __ bind(&function);
   __ Move(rax, Factory::function_class_symbol());
   __ jmp(&done);

   // Objects with a non-function constructor have class 'Object'.
   __ bind(&non_function_constructor);
   __ Move(rax, Factory::Object_symbol());
   __ jmp(&done);

   // Non-JS objects have class null.
   __ bind(&null);
   __ LoadRoot(rax, Heap::kNullValueRootIndex);

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

   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitLog(ZoneList<Expression*>* args) {
   // Conditionally generate a log call.
   // Args:
   //   0 (literal string): The type of logging (corresponds to the flags).
   //     This is used to determine whether or not to generate the log call.
   //   1 (string): Format string.  Access the string at argument index 2
   //     with '%2s' (see Logger::LogRuntime for all the formats).
   //   2 (array): Arguments to the format string.
   ASSERT_EQ(args->length(), 3);
 #ifdef ENABLE_LOGGING_AND_PROFILING
   if (CodeGenerator::ShouldGenerateLog(args->at(0))) {
     VisitForStackValue(args->at(1));
     VisitForStackValue(args->at(2));
     __ CallRuntime(Runtime::kLog, 2);
   }
 #endif
   // Finally, we're expected to leave a value on the top of the stack.
   __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitRandomHeapNumber(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 0);

   Label slow_allocate_heapnumber;
   Label heapnumber_allocated;

   __ AllocateHeapNumber(rbx, rcx, &slow_allocate_heapnumber);
   __ jmp(&heapnumber_allocated);

   __ bind(&slow_allocate_heapnumber);
   // Allocate a heap number.
   __ CallRuntime(Runtime::kNumberAlloc, 0);
   __ movq(rbx, rax);

   __ bind(&heapnumber_allocated);

   // Return a random uint32 number in rax.
   // The fresh HeapNumber is in rbx, which is callee-save on both x64 ABIs.
   __ PrepareCallCFunction(0);
   __ CallCFunction(ExternalReference::random_uint32_function(), 0);

   // Convert 32 random bits in rax to 0.(32 random bits) in a double
   // by computing:
   // ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
   __ movl(rcx, Immediate(0x49800000));  // 1.0 x 2^20 as single.
   __ movd(xmm1, rcx);
   __ movd(xmm0, rax);
   __ cvtss2sd(xmm1, xmm1);
   __ xorpd(xmm0, xmm1);
   __ subsd(xmm0, xmm1);
   __ movsd(FieldOperand(rbx, HeapNumber::kValueOffset), xmm0);

   __ movq(rax, rbx);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitSubString(ZoneList<Expression*>* args) {
   // Load the arguments on the stack and call the stub.
   SubStringStub stub;
   ASSERT(args->length() == 3);
   VisitForStackValue(args->at(0));
   VisitForStackValue(args->at(1));
   VisitForStackValue(args->at(2));
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitRegExpExec(ZoneList<Expression*>* args) {
   // Load the arguments on the stack and call the stub.
   RegExpExecStub stub;
   ASSERT(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(ZoneList<Expression*>* args) {
   ASSERT(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);
   __ movq(rax, FieldOperand(rax, JSValue::kValueOffset));

   __ bind(&done);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitMathPow(ZoneList<Expression*>* args) {
   // Load the arguments on the stack and call the runtime function.
   ASSERT(args->length() == 2);
   VisitForStackValue(args->at(0));
   VisitForStackValue(args->at(1));
   MathPowStub stub;
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitSetValueOf(ZoneList<Expression*>* args) {
   ASSERT(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.
   __ movq(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.
   __ movq(rdx, rax);
   __ RecordWrite(rbx, JSValue::kValueOffset, rdx, rcx);

   __ bind(&done);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitNumberToString(ZoneList<Expression*>* args) {
   ASSERT_EQ(args->length(), 1);

   // Load the argument on the stack and call the stub.
   VisitForStackValue(args->at(0));

   NumberToStringStub stub;
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitStringCharFromCode(ZoneList<Expression*>* args) {
   ASSERT(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(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 2);

   VisitForStackValue(args->at(0));
   VisitForAccumulatorValue(args->at(1));

   Register object = rbx;
   Register index = rax;
   Register scratch = rcx;
   Register result = rdx;

   __ pop(object);

   Label need_conversion;
   Label index_out_of_range;
   Label done;
   StringCharCodeAtGenerator 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
   // 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(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 2);

   VisitForStackValue(args->at(0));
   VisitForAccumulatorValue(args->at(1));

   Register object = rbx;
   Register index = rax;
   Register scratch1 = rcx;
   Register scratch2 = rdx;
   Register result = rax;

   __ pop(object);

   Label need_conversion;
   Label index_out_of_range;
   Label done;
   StringCharAtGenerator generator(object,
                                   index,
                                   scratch1,
                                   scratch2,
                                   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::kEmptyStringRootIndex);
   __ 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(ZoneList<Expression*>* args) {
   ASSERT_EQ(2, args->length());

   VisitForStackValue(args->at(0));
   VisitForStackValue(args->at(1));

   StringAddStub stub(NO_STRING_ADD_FLAGS);
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitStringCompare(ZoneList<Expression*>* args) {
   ASSERT_EQ(2, args->length());

   VisitForStackValue(args->at(0));
   VisitForStackValue(args->at(1));

   StringCompareStub stub;
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitMathSin(ZoneList<Expression*>* args) {
   // Load the argument on the stack and call the stub.
   TranscendentalCacheStub stub(TranscendentalCache::SIN,
                                TranscendentalCacheStub::TAGGED);
   ASSERT(args->length() == 1);
   VisitForStackValue(args->at(0));
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitMathCos(ZoneList<Expression*>* args) {
   // Load the argument on the stack and call the stub.
   TranscendentalCacheStub stub(TranscendentalCache::COS,
                                TranscendentalCacheStub::TAGGED);
   ASSERT(args->length() == 1);
   VisitForStackValue(args->at(0));
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitMathLog(ZoneList<Expression*>* args) {
   // Load the argument on the stack and call the stub.
   TranscendentalCacheStub stub(TranscendentalCache::LOG,
                                TranscendentalCacheStub::TAGGED);
   ASSERT(args->length() == 1);
   VisitForStackValue(args->at(0));
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitMathSqrt(ZoneList<Expression*>* args) {
   // Load the argument on the stack and call the runtime function.
   ASSERT(args->length() == 1);
   VisitForStackValue(args->at(0));
   __ CallRuntime(Runtime::kMath_sqrt, 1);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitCallFunction(ZoneList<Expression*>* args) {
   ASSERT(args->length() >= 2);

   int arg_count = args->length() - 2;  // For receiver and function.
   VisitForStackValue(args->at(0));  // Receiver.
   for (int i = 0; i < arg_count; i++) {
     VisitForStackValue(args->at(i + 1));
   }
   VisitForAccumulatorValue(args->at(arg_count + 1));  // Function.

   // InvokeFunction requires function in rdi. Move it in there.
   if (!result_register().is(rdi)) __ movq(rdi, result_register());
   ParameterCount count(arg_count);
   __ InvokeFunction(rdi, count, CALL_FUNCTION);
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitRegExpConstructResult(ZoneList<Expression*>* args) {
   RegExpConstructResultStub stub;
   ASSERT(args->length() == 3);
   VisitForStackValue(args->at(0));
   VisitForStackValue(args->at(1));
   VisitForStackValue(args->at(2));
   __ CallStub(&stub);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitSwapElements(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 3);
   VisitForStackValue(args->at(0));
   VisitForStackValue(args->at(1));
   VisitForStackValue(args->at(2));
   Label done;
   Label slow_case;
   Register object = rax;
   Register index_1 = rbx;
   Register index_2 = rcx;
   Register elements = rdi;
   Register temp = rdx;
   __ movq(object, Operand(rsp, 2 * kPointerSize));
   // Fetch the map and check if array is in fast case.
   // Check that object doesn't require security checks and
   // has no indexed interceptor.
   __ CmpObjectType(object, FIRST_JS_OBJECT_TYPE, temp);
   __ j(below, &slow_case);
   __ testb(FieldOperand(temp, Map::kBitFieldOffset),
            Immediate(KeyedLoadIC::kSlowCaseBitFieldMask));
   __ j(not_zero, &slow_case);

   // Check the object's elements are in fast case and writable.
   __ movq(elements, FieldOperand(object, JSObject::kElementsOffset));
   __ CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
                  Heap::kFixedArrayMapRootIndex);
   __ j(not_equal, &slow_case);

   // Check that both indices are smis.
   __ movq(index_1, Operand(rsp, 1 * kPointerSize));
   __ movq(index_2, Operand(rsp, 0 * kPointerSize));
   __ JumpIfNotBothSmi(index_1, index_2, &slow_case);

   // Check that both indices are valid.
   // The JSArray length field is a smi since the array is in fast case mode.
   __ movq(temp, FieldOperand(object, JSArray::kLengthOffset));
   __ SmiCompare(temp, index_1);
   __ j(below_equal, &slow_case);
   __ SmiCompare(temp, index_2);
   __ j(below_equal, &slow_case);

   __ SmiToInteger32(index_1, index_1);
   __ SmiToInteger32(index_2, index_2);
   // Bring addresses into index1 and index2.
   __ lea(index_1, FieldOperand(elements, index_1, times_pointer_size,
                                FixedArray::kHeaderSize));
   __ lea(index_2, FieldOperand(elements, index_2, times_pointer_size,
                                FixedArray::kHeaderSize));

   // Swap elements.  Use object and temp as scratch registers.
   __ movq(object, Operand(index_1, 0));
   __ movq(temp,   Operand(index_2, 0));
   __ movq(Operand(index_2, 0), object);
   __ movq(Operand(index_1, 0), temp);

   Label new_space;
   __ InNewSpace(elements, temp, equal, &new_space);

   __ movq(object, elements);
   __ RecordWriteHelper(object, index_1, temp);
   __ RecordWriteHelper(elements, index_2, temp);

   __ bind(&new_space);
   // We are done. Drop elements from the stack, and return undefined.
   __ addq(rsp, Immediate(3 * kPointerSize));
   __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
   __ jmp(&done);

   __ bind(&slow_case);
   __ CallRuntime(Runtime::kSwapElements, 3);

   __ bind(&done);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitGetFromCache(ZoneList<Expression*>* args) {
   ASSERT_EQ(2, args->length());

   ASSERT_NE(NULL, args->at(0)->AsLiteral());
   int cache_id = Smi::cast(*(args->at(0)->AsLiteral()->handle()))->value();

   Handle<FixedArray> jsfunction_result_caches(
       Top::global_context()->jsfunction_result_caches());
   if (jsfunction_result_caches->length() <= cache_id) {
     __ Abort("Attempt to use undefined cache.");
     __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
     context()->Plug(rax);
     return;
   }

   VisitForAccumulatorValue(args->at(1));

   Register key = rax;
   Register cache = rbx;
   Register tmp = rcx;
   __ movq(cache, ContextOperand(rsi, Context::GLOBAL_INDEX));
   __ movq(cache,
           FieldOperand(cache, GlobalObject::kGlobalContextOffset));
   __ movq(cache,
           ContextOperand(cache, Context::JSFUNCTION_RESULT_CACHES_INDEX));
   __ movq(cache,
           FieldOperand(cache, FixedArray::OffsetOfElementAt(cache_id)));

   NearLabel done, not_found;
   // tmp now holds finger offset as a smi.
   ASSERT(kSmiTag == 0 && kSmiTagSize == 1);
   __ movq(tmp, FieldOperand(cache, JSFunctionResultCache::kFingerOffset));
   SmiIndex index =
       __ SmiToIndex(kScratchRegister, tmp, kPointerSizeLog2);
   __ cmpq(key, FieldOperand(cache,
                             index.reg,
                             index.scale,
                             FixedArray::kHeaderSize));
   __ j(not_equal, &not_found);
   __ movq(rax, FieldOperand(cache,
                             index.reg,
                             index.scale,
                             FixedArray::kHeaderSize + kPointerSize));
   __ jmp(&done);

   __ bind(&not_found);
   // Call runtime to perform the lookup.
   __ push(cache);
   __ push(key);
   __ CallRuntime(Runtime::kGetFromCache, 2);

   __ bind(&done);
   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitIsRegExpEquivalent(ZoneList<Expression*>* args) {
   ASSERT_EQ(2, args->length());

   Register right = rax;
   Register left = rbx;
   Register tmp = rcx;

   VisitForStackValue(args->at(0));
   VisitForAccumulatorValue(args->at(1));
   __ pop(left);

   NearLabel done, fail, ok;
   __ cmpq(left, right);
   __ j(equal, &ok);
   // Fail if either is a non-HeapObject.
   Condition either_smi = masm()->CheckEitherSmi(left, right, tmp);
   __ j(either_smi, &fail);
   __ j(zero, &fail);
   __ movq(tmp, FieldOperand(left, HeapObject::kMapOffset));
   __ cmpb(FieldOperand(tmp, Map::kInstanceTypeOffset),
           Immediate(JS_REGEXP_TYPE));
   __ j(not_equal, &fail);
   __ cmpq(tmp, FieldOperand(right, HeapObject::kMapOffset));
   __ j(not_equal, &fail);
   __ movq(tmp, FieldOperand(left, JSRegExp::kDataOffset));
   __ cmpq(tmp, FieldOperand(right, JSRegExp::kDataOffset));
   __ j(equal, &ok);
   __ bind(&fail);
   __ Move(rax, Factory::false_value());
   __ jmp(&done);
   __ bind(&ok);
   __ Move(rax, Factory::true_value());
   __ bind(&done);

   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitHasCachedArrayIndex(ZoneList<Expression*>* args) {
   ASSERT(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(TOS_REG, true, if_true, if_false);
   __ j(zero, if_true);
   __ jmp(if_false);

   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::EmitGetCachedArrayIndex(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 1);
   VisitForAccumulatorValue(args->at(0));

   if (FLAG_debug_code) {
     __ AbortIfNotString(rax);
   }

   __ movl(rax, FieldOperand(rax, String::kHashFieldOffset));
   ASSERT(String::kHashShift >= kSmiTagSize);
   __ IndexFromHash(rax, rax);

   context()->Plug(rax);
 }


 void FullCodeGenerator::EmitFastAsciiArrayJoin(ZoneList<Expression*>* args) {
   context()->Plug(Heap::kUndefinedValueRootIndex);
 }


 void FullCodeGenerator::VisitCallRuntime(CallRuntime* expr) {
   Handle<String> name = expr->name();
   if (name->length() > 0 && name->Get(0) == '_') {
     Comment cmnt(masm_, "[ InlineRuntimeCall");
     EmitInlineRuntimeCall(expr);
     return;
   }

   Comment cmnt(masm_, "[ CallRuntime");
   ZoneList<Expression*>* args = expr->arguments();

   if (expr->is_jsruntime()) {
     // Prepare for calling JS runtime function.
     __ movq(rax, GlobalObjectOperand());
     __ push(FieldOperand(rax, GlobalObject::kBuiltinsOffset));
   }

   // Push the arguments ("left-to-right").
   int arg_count = args->length();
   for (int i = 0; i < arg_count; i++) {
     VisitForStackValue(args->at(i));
   }

   if (expr->is_jsruntime()) {
     // Call the JS runtime function using a call IC.
     __ Move(rcx, expr->name());
     InLoopFlag in_loop = (loop_depth() > 0) ? IN_LOOP : NOT_IN_LOOP;
     Handle<Code> ic = StubCache::ComputeCallInitialize(arg_count, in_loop);
     EmitCallIC(ic, RelocInfo::CODE_TARGET);
     // Restore context register.
     __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   } else {
     __ 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* prop = expr->expression()->AsProperty();
       Variable* var = expr->expression()->AsVariableProxy()->AsVariable();

       if (prop != NULL) {
         if (prop->is_synthetic()) {
           // Result of deleting parameters is false, even when they rewrite
           // to accesses on the arguments object.
           context()->Plug(false);
         } else {
           VisitForStackValue(prop->obj());
           VisitForStackValue(prop->key());
           __ Push(Smi::FromInt(strict_mode_flag()));
           __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
           context()->Plug(rax);
         }
       } else if (var != NULL) {
         // Delete of an unqualified identifier is disallowed in strict mode
         // but "delete this" is.
         ASSERT(strict_mode_flag() == kNonStrictMode || var->is_this());
         if (var->is_global()) {
           __ push(GlobalObjectOperand());
           __ Push(var->name());
           __ Push(Smi::FromInt(kNonStrictMode));
           __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
           context()->Plug(rax);
         } else if (var->AsSlot() != NULL &&
                    var->AsSlot()->type() != Slot::LOOKUP) {
           // Result of deleting non-global, non-dynamic variables is false.
           // The subexpression does not have side effects.
           context()->Plug(false);
         } 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::kDeleteContextSlot, 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 {
         Label materialize_true, materialize_false;
         Label* if_true = NULL;
         Label* if_false = NULL;
         Label* fall_through = NULL;
         // Notice that the labels are swapped.
         context()->PrepareTest(&materialize_true, &materialize_false,
                                &if_false, &if_true, &fall_through);
         if (context()->IsTest()) ForwardBailoutToChild(expr);
         VisitForControl(expr->expression(), if_true, if_false, fall_through);
         context()->Plug(if_false, if_true);  // Labels swapped.
       }
       break;
     }

     case Token::TYPEOF: {
       Comment cmnt(masm_, "[ UnaryOperation (TYPEOF)");
       { StackValueContext context(this);
         VisitForTypeofValue(expr->expression());
       }
       __ CallRuntime(Runtime::kTypeof, 1);
       context()->Plug(rax);
       break;
     }

     case Token::ADD: {
       Comment cmt(masm_, "[ UnaryOperation (ADD)");
       VisitForAccumulatorValue(expr->expression());
       Label no_conversion;
       Condition is_smi = masm_->CheckSmi(result_register());
       __ j(is_smi, &no_conversion);
       ToNumberStub convert_stub;
       __ CallStub(&convert_stub);
       __ bind(&no_conversion);
       context()->Plug(result_register());
       break;
     }

     case Token::SUB: {
       Comment cmt(masm_, "[ UnaryOperation (SUB)");
       bool can_overwrite = expr->expression()->ResultOverwriteAllowed();
       UnaryOverwriteMode overwrite =
           can_overwrite ? UNARY_OVERWRITE : UNARY_NO_OVERWRITE;
       GenericUnaryOpStub stub(Token::SUB, overwrite, NO_UNARY_FLAGS);
       // GenericUnaryOpStub expects the argument to be in the
       // accumulator register rax.
       VisitForAccumulatorValue(expr->expression());
       __ CallStub(&stub);
       context()->Plug(rax);
       break;
     }

     case Token::BIT_NOT: {
       Comment cmt(masm_, "[ UnaryOperation (BIT_NOT)");
       // The generic unary operation stub expects the argument to be
       // in the accumulator register rax.
       VisitForAccumulatorValue(expr->expression());
       Label done;
       bool inline_smi_case = ShouldInlineSmiCase(expr->op());
       if (inline_smi_case) {
         Label call_stub;
         __ JumpIfNotSmi(rax, &call_stub);
         __ SmiNot(rax, rax);
         __ jmp(&done);
         __ bind(&call_stub);
       }
       bool overwrite = expr->expression()->ResultOverwriteAllowed();
       UnaryOverwriteMode mode =
           overwrite ? UNARY_OVERWRITE : UNARY_NO_OVERWRITE;
       UnaryOpFlags flags = inline_smi_case
           ? NO_UNARY_SMI_CODE_IN_STUB
           : NO_UNARY_FLAGS;
       GenericUnaryOpStub stub(Token::BIT_NOT, mode, flags);
       __ CallStub(&stub);
       __ bind(&done);
       context()->Plug(rax);
       break;
     }

     default:
       UNREACHABLE();
   }
 }


 void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
   Comment cmnt(masm_, "[ CountOperation");
   SetSourcePosition(expr->position());

   // Invalid left-hand-sides are rewritten to have a 'throw
   // ReferenceError' as the left-hand side.
   if (!expr->expression()->IsValidLeftHandSide()) {
     VisitForEffect(expr->expression());
     return;
   }

   // Expression can only be a property, a global or a (parameter or local)
   // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* prop = expr->expression()->AsProperty();
   // In case of a property we use the uninitialized expression context
   // of the key to detect a named property.
   if (prop != NULL) {
     assign_type =
         (prop->key()->IsPropertyName()) ? NAMED_PROPERTY : KEYED_PROPERTY;
   }

   // Evaluate expression and get value.
   if (assign_type == VARIABLE) {
     ASSERT(expr->expression()->AsVariableProxy()->var() != NULL);
     AccumulatorValueContext context(this);
     EmitVariableLoad(expr->expression()->AsVariableProxy()->var());
   } else {
     // Reserve space for result of postfix operation.
     if (expr->is_postfix() && !context()->IsEffect()) {
       __ Push(Smi::FromInt(0));
     }
     if (assign_type == NAMED_PROPERTY) {
       VisitForAccumulatorValue(prop->obj());
       __ push(rax);  // Copy of receiver, needed for later store.
       EmitNamedPropertyLoad(prop);
     } else {
       if (prop->is_arguments_access()) {
         VariableProxy* obj_proxy = prop->obj()->AsVariableProxy();
         MemOperand slot_operand =
             EmitSlotSearch(obj_proxy->var()->AsSlot(), rcx);
         __ push(slot_operand);
         __ Move(rax, prop->key()->AsLiteral()->handle());
       } else {
         VisitForStackValue(prop->obj());
         VisitForAccumulatorValue(prop->key());
       }
       __ movq(rdx, Operand(rsp, 0));  // Leave receiver on stack
       __ push(rax);  // Copy of key, needed for later store.
       EmitKeyedPropertyLoad(prop);
     }
   }

   // We need a second deoptimization point after loading the value
   // in case evaluating the property load my have a side effect.
   PrepareForBailout(expr->increment(), TOS_REG);

   // Call ToNumber only if operand is not a smi.
   NearLabel no_conversion;
   Condition is_smi;
   is_smi = masm_->CheckSmi(rax);
   __ j(is_smi, &no_conversion);
   ToNumberStub convert_stub;
   __ CallStub(&convert_stub);
   __ bind(&no_conversion);

   // 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:
           __ movq(Operand(rsp, kPointerSize), rax);
           break;
         case KEYED_PROPERTY:
           __ movq(Operand(rsp, 2 * kPointerSize), rax);
           break;
       }
     }
   }

   // Inline smi case if we are in a loop.
   NearLabel stub_call, done;
   JumpPatchSite patch_site(masm_);

   if (ShouldInlineSmiCase(expr->op())) {
     if (expr->op() == Token::INC) {
       __ SmiAddConstant(rax, rax, Smi::FromInt(1));
     } else {
       __ SmiSubConstant(rax, rax, Smi::FromInt(1));
     }
     __ j(overflow, &stub_call);
     // We could eliminate this smi check if we split the code at
     // the first smi check before calling ToNumber.
     patch_site.EmitJumpIfSmi(rax, &done);

     __ bind(&stub_call);
     // Call stub. Undo operation first.
     if (expr->op() == Token::INC) {
       __ SmiSubConstant(rax, rax, Smi::FromInt(1));
     } else {
       __ SmiAddConstant(rax, rax, Smi::FromInt(1));
     }
   }

   // Record position before stub call.
   SetSourcePosition(expr->position());

   // Call stub for +1/-1.
   TypeRecordingBinaryOpStub stub(expr->binary_op(), NO_OVERWRITE);
   if (expr->op() == Token::INC) {
     __ Move(rdx, Smi::FromInt(1));
   } else {
     __ movq(rdx, rax);
     __ Move(rax, Smi::FromInt(1));
   }
   EmitCallIC(stub.GetCode(), &patch_site);
   __ 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(rcx, prop->key()->AsLiteral()->handle());
       __ pop(rdx);
       Handle<Code> ic(Builtins::builtin(
           is_strict() ? Builtins::StoreIC_Initialize_Strict
                       : Builtins::StoreIC_Initialize));
       EmitCallIC(ic, RelocInfo::CODE_TARGET);
       PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
       if (expr->is_postfix()) {
         if (!context()->IsEffect()) {
           context()->PlugTOS();
         }
       } else {
         context()->Plug(rax);
       }
       break;
     }
     case KEYED_PROPERTY: {
       __ pop(rcx);
       __ pop(rdx);
       Handle<Code> ic(Builtins::builtin(
           is_strict() ? Builtins::KeyedStoreIC_Initialize_Strict
                       : Builtins::KeyedStoreIC_Initialize));
       EmitCallIC(ic, RelocInfo::CODE_TARGET);
       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();
   ASSERT(!context()->IsEffect());
   ASSERT(!context()->IsTest());

   if (proxy != NULL && !proxy->var()->is_this() && proxy->var()->is_global()) {
     Comment cmnt(masm_, "Global variable");
     __ Move(rcx, proxy->name());
     __ movq(rax, GlobalObjectOperand());
     Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
     // Use a regular load, not a contextual load, to avoid a reference
     // error.
     EmitCallIC(ic, RelocInfo::CODE_TARGET);
     PrepareForBailout(expr, TOS_REG);
     context()->Plug(rax);
   } else if (proxy != NULL &&
              proxy->var()->AsSlot() != NULL &&
              proxy->var()->AsSlot()->type() == Slot::LOOKUP) {
     Label done, slow;

     // Generate code for loading from variables potentially shadowed
     // by eval-introduced variables.
     Slot* slot = proxy->var()->AsSlot();
     EmitDynamicLoadFromSlotFastCase(slot, INSIDE_TYPEOF, &slow, &done);

     __ bind(&slow);
     __ push(rsi);
     __ Push(proxy->name());
     __ CallRuntime(Runtime::kLoadContextSlotNoReferenceError, 2);
     PrepareForBailout(expr, TOS_REG);
     __ bind(&done);

     context()->Plug(rax);
   } else {
     // This expression cannot throw a reference error at the top level.
     context()->HandleExpression(expr);
   }
 }


 bool FullCodeGenerator::TryLiteralCompare(Token::Value op,
                                           Expression* left,
                                           Expression* right,
                                           Label* if_true,
                                           Label* if_false,
                                           Label* fall_through) {
   if (op != Token::EQ && op != Token::EQ_STRICT) return false;

   // Check for the pattern: typeof <expression> == <string literal>.
   Literal* right_literal = right->AsLiteral();
   if (right_literal == NULL) return false;
   Handle<Object> right_literal_value = right_literal->handle();
   if (!right_literal_value->IsString()) return false;
   UnaryOperation* left_unary = left->AsUnaryOperation();
   if (left_unary == NULL || left_unary->op() != Token::TYPEOF) return false;
   Handle<String> check = Handle<String>::cast(right_literal_value);

   { AccumulatorValueContext context(this);
     VisitForTypeofValue(left_unary->expression());
   }
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);

   if (check->Equals(Heap::number_symbol())) {
     __ JumpIfSmi(rax, if_true);
     __ movq(rax, FieldOperand(rax, HeapObject::kMapOffset));
     __ CompareRoot(rax, Heap::kHeapNumberMapRootIndex);
     Split(equal, if_true, if_false, fall_through);
   } else if (check->Equals(Heap::string_symbol())) {
     __ 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 (check->Equals(Heap::boolean_symbol())) {
     __ CompareRoot(rax, Heap::kTrueValueRootIndex);
     __ j(equal, if_true);
     __ CompareRoot(rax, Heap::kFalseValueRootIndex);
     Split(equal, if_true, if_false, fall_through);
   } else if (check->Equals(Heap::undefined_symbol())) {
     __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
     __ j(equal, if_true);
     __ JumpIfSmi(rax, if_false);
     // Check for undetectable objects => true.
     __ movq(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 (check->Equals(Heap::function_symbol())) {
     __ JumpIfSmi(rax, if_false);
     __ CmpObjectType(rax, FIRST_FUNCTION_CLASS_TYPE, rdx);
     Split(above_equal, if_true, if_false, fall_through);
   } else if (check->Equals(Heap::object_symbol())) {
     __ JumpIfSmi(rax, if_false);
     __ CompareRoot(rax, Heap::kNullValueRootIndex);
     __ j(equal, if_true);
     __ CmpObjectType(rax, FIRST_JS_OBJECT_TYPE, rdx);
     __ j(below, if_false);
     __ CmpInstanceType(rdx, FIRST_FUNCTION_CLASS_TYPE);
     __ j(above_equal, 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);
   }

   return true;
 }


 void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   Comment cmnt(masm_, "[ CompareOperation");
   SetSourcePosition(expr->position());

   // 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);

   // First we try a fast inlined version of the compare when one of
   // the operands is a literal.
   Token::Value op = expr->op();
   Expression* left = expr->left();
   Expression* right = expr->right();
   if (TryLiteralCompare(op, left, right, if_true, if_false, fall_through)) {
     context()->Plug(if_true, if_false);
     return;
   }

   VisitForStackValue(expr->left());
   switch (op) {
     case Token::IN:
       VisitForStackValue(expr->right());
       __ InvokeBuiltin(Builtins::IN, CALL_FUNCTION);
       PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
       __ CompareRoot(rax, Heap::kTrueValueRootIndex);
       Split(equal, if_true, if_false, fall_through);
       break;

     case Token::INSTANCEOF: {
       VisitForStackValue(expr->right());
       InstanceofStub stub(InstanceofStub::kNoFlags);
       __ CallStub(&stub);
       PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
       __ testq(rax, rax);
        // The stub returns 0 for true.
       Split(zero, if_true, if_false, fall_through);
       break;
     }

     default: {
       VisitForAccumulatorValue(expr->right());
       Condition cc = no_condition;
       bool strict = false;
       switch (op) {
         case Token::EQ_STRICT:
           strict = true;
           // Fall through.
         case Token::EQ:
           cc = equal;
           __ pop(rdx);
           break;
         case Token::LT:
           cc = less;
           __ pop(rdx);
           break;
         case Token::GT:
           // Reverse left and right sizes to obtain ECMA-262 conversion order.
           cc = less;
           __ movq(rdx, result_register());
           __ pop(rax);
          break;
         case Token::LTE:
           // Reverse left and right sizes to obtain ECMA-262 conversion order.
           cc = greater_equal;
           __ movq(rdx, result_register());
           __ pop(rax);
           break;
         case Token::GTE:
           cc = greater_equal;
           __ pop(rdx);
           break;
         case Token::IN:
         case Token::INSTANCEOF:
         default:
           UNREACHABLE();
       }

       bool inline_smi_code = ShouldInlineSmiCase(op);
       JumpPatchSite patch_site(masm_);
       if (inline_smi_code) {
         NearLabel slow_case;
         __ movq(rcx, rdx);
         __ or_(rcx, rax);
         patch_site.EmitJumpIfNotSmi(rcx, &slow_case);
         __ cmpq(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 = CompareIC::GetUninitialized(op);
       EmitCallIC(ic, &patch_site);

       PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
       __ testq(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::VisitCompareToNull(CompareToNull* expr) {
   Comment cmnt(masm_, "[ CompareToNull");
   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(expr->expression());
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
   __ CompareRoot(rax, Heap::kNullValueRootIndex);
   if (expr->is_strict()) {
     Split(equal, if_true, if_false, fall_through);
   } else {
     __ j(equal, if_true);
     __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
     __ j(equal, if_true);
     Condition is_smi = masm_->CheckSmi(rax);
     __ j(is_smi, if_false);
     // It can be an undetectable object.
     __ movq(rdx, FieldOperand(rax, HeapObject::kMapOffset));
     __ testb(FieldOperand(rdx, Map::kBitFieldOffset),
              Immediate(1 << Map::kIsUndetectable));
     Split(not_zero, if_true, if_false, fall_through);
   }
   context()->Plug(if_true, if_false);
 }


 void FullCodeGenerator::VisitThisFunction(ThisFunction* expr) {
   __ movq(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   context()->Plug(rax);
 }


 Register FullCodeGenerator::result_register() {
   return rax;
 }


 Register FullCodeGenerator::context_register() {
   return rsi;
 }


 void FullCodeGenerator::EmitCallIC(Handle<Code> ic, RelocInfo::Mode mode) {
   ASSERT(mode == RelocInfo::CODE_TARGET ||
          mode == RelocInfo::CODE_TARGET_CONTEXT);
   switch (ic->kind()) {
     case Code::LOAD_IC:
       __ IncrementCounter(&Counters::named_load_full, 1);
       break;
     case Code::KEYED_LOAD_IC:
       __ IncrementCounter(&Counters::keyed_load_full, 1);
       break;
     case Code::STORE_IC:
       __ IncrementCounter(&Counters::named_store_full, 1);
       break;
     case Code::KEYED_STORE_IC:
       __ IncrementCounter(&Counters::keyed_store_full, 1);
     default:
       break;
   }

   __ call(ic, mode);

   // Crankshaft doesn't need patching of inlined loads and stores.
   // When compiling the snapshot we need to produce code that works
   // with and without Crankshaft.
   if (V8::UseCrankshaft() && !Serializer::enabled()) {
     return;
   }

   // If we're calling a (keyed) load or store stub, we have to mark
   // the call as containing no inlined code so we will not attempt to
   // patch it.
   switch (ic->kind()) {
     case Code::LOAD_IC:
     case Code::KEYED_LOAD_IC:
     case Code::STORE_IC:
     case Code::KEYED_STORE_IC:
       __ nop();  // Signals no inlined code.
       break;
     default:
       // Do nothing.
       break;
   }
 }


 void FullCodeGenerator::EmitCallIC(Handle<Code> ic, JumpPatchSite* patch_site) {
   switch (ic->kind()) {
     case Code::LOAD_IC:
       __ IncrementCounter(&Counters::named_load_full, 1);
       break;
     case Code::KEYED_LOAD_IC:
       __ IncrementCounter(&Counters::keyed_load_full, 1);
       break;
     case Code::STORE_IC:
       __ IncrementCounter(&Counters::named_store_full, 1);
       break;
     case Code::KEYED_STORE_IC:
       __ IncrementCounter(&Counters::keyed_store_full, 1);
     default:
       break;
   }

   __ call(ic, RelocInfo::CODE_TARGET);
   if (patch_site != NULL && patch_site->is_bound()) {
     patch_site->EmitPatchInfo();
   } else {
     __ nop();  // Signals no inlined code.
   }
 }


 void FullCodeGenerator::StoreToFrameField(int frame_offset, Register value) {
   ASSERT(IsAligned(frame_offset, kPointerSize));
   __ movq(Operand(rbp, frame_offset), value);
 }


 void FullCodeGenerator::LoadContextField(Register dst, int context_index) {
   __ movq(dst, ContextOperand(rsi, context_index));
 }


 // ----------------------------------------------------------------------------
 // Non-local control flow support.


 void FullCodeGenerator::EnterFinallyBlock() {
   ASSERT(!result_register().is(rdx));
   ASSERT(!result_register().is(rcx));
   // Cook return address on top of stack (smi encoded Code* delta)
   __ movq(rdx, Operand(rsp, 0));
   __ Move(rcx, masm_->CodeObject());
   __ subq(rdx, rcx);
   __ Integer32ToSmi(rdx, rdx);
   __ movq(Operand(rsp, 0), rdx);
   // Store result register while executing finally block.
   __ push(result_register());
 }


 void FullCodeGenerator::ExitFinallyBlock() {
   ASSERT(!result_register().is(rdx));
   ASSERT(!result_register().is(rcx));
   // Restore result register from stack.
   __ pop(result_register());
   // Uncook return address.
   __ movq(rdx, Operand(rsp, 0));
   __ SmiToInteger32(rdx, rdx);
   __ Move(rcx, masm_->CodeObject());
   __ addq(rdx, rcx);
   __ movq(Operand(rsp, 0), rdx);
   // And return.
   __ ret(0);
 }


 #undef __


 } }  // namespace v8::internal

 #endif  // V8_TARGET_ARCH_X64