text: // Copyright 2015 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #if V8_TARGET_ARCH_S390
  
  #include "src/ast/compile-time-value.h"
  #include "src/ast/scopes.h"
  #include "src/builtins/builtins-constructor.h"
  #include "src/code-factory.h"
  #include "src/code-stubs.h"
  #include "src/codegen.h"
  #include "src/compilation-info.h"
  #include "src/compiler.h"
  #include "src/debug/debug.h"
  #include "src/full-codegen/full-codegen.h"
  #include "src/ic/ic.h"
  
  #include "src/s390/code-stubs-s390.h"
  #include "src/s390/macro-assembler-s390.h"
  
  namespace v8 {
  namespace internal {
  
  #define __ ACCESS_MASM(masm())
  
  // A patch site is a location in the code which it is possible to patch. This
  // class has a number of methods to emit the code which is patchable and the
  // method EmitPatchInfo to record a marker back to the patchable code. This
  // marker is a cmpi rx, #yyy instruction, and x * 0x0000ffff + yyy (raw 16 bit
  // immediate value is used) is the delta from the pc to the first instruction of
  // the patchable code.
  // See PatchInlinedSmiCode in ic-s390.cc for the code that patches it
  class JumpPatchSite BASE_EMBEDDED {
   public:
    explicit JumpPatchSite(MacroAssembler* masm) : masm_(masm) {
  #ifdef DEBUG
      info_emitted_ = false;
  #endif
    }
  
    ~JumpPatchSite() { DCHECK(patch_site_.is_bound() == info_emitted_); }
  
    // When initially emitting this ensure that a jump is always generated to skip
    // the inlined smi code.
    void EmitJumpIfNotSmi(Register reg, Label* target) {
      DCHECK(!patch_site_.is_bound() && !info_emitted_);
      __ bind(&patch_site_);
      __ CmpP(reg, reg);
  // Emit the Nop to make bigger place for patching on 31-bit
  // as the TestIfSmi sequence uses 4-byte TMLL
  #ifndef V8_TARGET_ARCH_S390X
      __ nop();
  #endif
      __ beq(target);  // Always taken before patched.
    }
  
    // When initially emitting this ensure that a jump is never generated to skip
    // the inlined smi code.
    void EmitJumpIfSmi(Register reg, Label* target) {
      DCHECK(!patch_site_.is_bound() && !info_emitted_);
      __ bind(&patch_site_);
      __ CmpP(reg, reg);
  // Emit the Nop to make bigger place for patching on 31-bit
  // as the TestIfSmi sequence uses 4-byte TMLL
  #ifndef V8_TARGET_ARCH_S390X
      __ nop();
  #endif
      __ bne(target);  // Never taken before patched.
    }
  
    void EmitPatchInfo() {
      if (patch_site_.is_bound()) {
        int delta_to_patch_site = masm_->SizeOfCodeGeneratedSince(&patch_site_);
        DCHECK(is_int16(delta_to_patch_site));
        __ chi(r0, Operand(delta_to_patch_site));
  #ifdef DEBUG
        info_emitted_ = true;
  #endif
      } else {
        __ nop();
        __ nop();
      }
    }
  
   private:
    MacroAssembler* masm() { return masm_; }
    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.  The actual
  // argument count matches the formal parameter count expected by the
  // function.
  //
  // The live registers are:
  //   o r3: the JS function object being called (i.e., ourselves)
  //   o r5: the new target value
  //   o cp: our context
  //   o fp: our caller's frame pointer
  //   o sp: stack pointer
  //   o lr: return address
  //   o ip: our own function entry (required by the prologue)
  //
  // The function builds a JS frame.  Please see JavaScriptFrameConstants in
  // frames-s390.h for its layout.
  void FullCodeGenerator::Generate() {
    CompilationInfo* info = info_;
    profiling_counter_ = isolate()->factory()->NewCell(
        Handle<Smi>(Smi::FromInt(FLAG_interrupt_budget), isolate()));
    SetFunctionPosition(literal());
    Comment cmnt(masm_, "[ function compiled by full code generator");
  
    ProfileEntryHookStub::MaybeCallEntryHook(masm_);
  
    if (FLAG_debug_code && info->ExpectsJSReceiverAsReceiver()) {
      int receiver_offset = info->scope()->num_parameters() * kPointerSize;
      __ LoadP(r4, MemOperand(sp, receiver_offset), r0);
      __ AssertNotSmi(r4);
      __ CompareObjectType(r4, r4, no_reg, FIRST_JS_RECEIVER_TYPE);
      __ Assert(ge, kSloppyFunctionExpectsJSReceiverReceiver);
    }
  
    // Open a frame scope to indicate that there is a frame on the stack.  The
    // MANUAL indicates that the scope shouldn't actually generate code to set up
    // the frame (that is done below).
    FrameScope frame_scope(masm_, StackFrame::MANUAL);
    int prologue_offset = masm_->pc_offset();
  
    info->set_prologue_offset(prologue_offset);
    __ Prologue(info->GeneratePreagedPrologue(), ip, prologue_offset);
  
    // Increment invocation count for the function.
    {
      Comment cmnt(masm_, "[ Increment invocation count");
      __ LoadP(r6, FieldMemOperand(r3, JSFunction::kFeedbackVectorOffset));
      __ LoadP(r6, FieldMemOperand(r6, Cell::kValueOffset));
      __ LoadP(r1, FieldMemOperand(
                       r6, FeedbackVector::kInvocationCountIndex * kPointerSize +
                               FeedbackVector::kHeaderSize));
      __ AddSmiLiteral(r1, r1, Smi::FromInt(1), r0);
      __ StoreP(r1, FieldMemOperand(
                        r6, FeedbackVector::kInvocationCountIndex * kPointerSize +
                                FeedbackVector::kHeaderSize));
    }
  
    {
      Comment cmnt(masm_, "[ Allocate locals");
      int locals_count = info->scope()->num_stack_slots();
      OperandStackDepthIncrement(locals_count);
      if (locals_count > 0) {
        if (locals_count >= 128) {
          Label ok;
          __ AddP(ip, sp, Operand(-(locals_count * kPointerSize)));
          __ LoadRoot(r5, Heap::kRealStackLimitRootIndex);
          __ CmpLogicalP(ip, r5);
          __ bge(&ok, Label::kNear);
          __ CallRuntime(Runtime::kThrowStackOverflow);
          __ bind(&ok);
        }
        __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
        int kMaxPushes = FLAG_optimize_for_size ? 4 : 32;
        if (locals_count >= kMaxPushes) {
          int loop_iterations = locals_count / kMaxPushes;
          __ mov(r4, Operand(loop_iterations));
          Label loop_header;
          __ bind(&loop_header);
          // Do pushes.
          // TODO(joransiu): Use MVC for better performance
          __ lay(sp, MemOperand(sp, -kMaxPushes * kPointerSize));
          for (int i = 0; i < kMaxPushes; i++) {
            __ StoreP(ip, MemOperand(sp, i * kPointerSize));
          }
          // Continue loop if not done.
          __ BranchOnCount(r4, &loop_header);
        }
        int remaining = locals_count % kMaxPushes;
        // Emit the remaining pushes.
        // TODO(joransiu): Use MVC for better performance
        if (remaining > 0) {
          __ lay(sp, MemOperand(sp, -remaining * kPointerSize));
          for (int i = 0; i < remaining; i++) {
            __ StoreP(ip, MemOperand(sp, i * kPointerSize));
          }
        }
      }
    }
  
    bool function_in_register_r3 = true;
  
    // Possibly allocate a local context.
    if (info->scope()->NeedsContext()) {
      // Argument to NewContext is the function, which is still in r3.
      Comment cmnt(masm_, "[ Allocate context");
      bool need_write_barrier = true;
      int slots = info->scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
      if (info->scope()->is_script_scope()) {
        __ push(r3);
        __ Push(info->scope()->scope_info());
        __ CallRuntime(Runtime::kNewScriptContext);
        // The new target value is not used, clobbering is safe.
        DCHECK_NULL(info->scope()->new_target_var());
      } else {
        if (info->scope()->new_target_var() != nullptr) {
          __ push(r5);  // Preserve new target.
        }
        if (slots <= ConstructorBuiltins::MaximumFunctionContextSlots()) {
          Callable callable = CodeFactory::FastNewFunctionContext(
              isolate(), info->scope()->scope_type());
          __ mov(FastNewFunctionContextDescriptor::SlotsRegister(),
                 Operand(slots));
          __ Call(callable.code(), RelocInfo::CODE_TARGET);
          // Result of the FastNewFunctionContext builtin is always in new space.
          need_write_barrier = false;
        } else {
          __ push(r3);
          __ Push(Smi::FromInt(info->scope()->scope_type()));
          __ CallRuntime(Runtime::kNewFunctionContext);
        }
        if (info->scope()->new_target_var() != nullptr) {
          __ pop(r5);  // Preserve new target.
        }
      }
      function_in_register_r3 = false;
      // Context is returned in r2.  It replaces the context passed to us.
      // It's saved in the stack and kept live in cp.
      __ LoadRR(cp, r2);
      __ StoreP(r2, MemOperand(fp, StandardFrameConstants::kContextOffset));
      // Copy any necessary parameters into the context.
      int num_parameters = info->scope()->num_parameters();
      int first_parameter = info->scope()->has_this_declaration() ? -1 : 0;
      for (int i = first_parameter; i < num_parameters; i++) {
        Variable* var =
            (i == -1) ? info->scope()->receiver() : info->scope()->parameter(i);
        if (var->IsContextSlot()) {
          int parameter_offset = StandardFrameConstants::kCallerSPOffset +
                                 (num_parameters - 1 - i) * kPointerSize;
          // Load parameter from stack.
          __ LoadP(r2, MemOperand(fp, parameter_offset), r0);
          // Store it in the context.
          MemOperand target = ContextMemOperand(cp, var->index());
          __ StoreP(r2, target);
  
          // Update the write barrier.
          if (need_write_barrier) {
            __ RecordWriteContextSlot(cp, target.offset(), r2, r4,
                                      kLRHasBeenSaved, kDontSaveFPRegs);
          } else if (FLAG_debug_code) {
            Label done;
            __ JumpIfInNewSpace(cp, r2, &done);
            __ Abort(kExpectedNewSpaceObject);
            __ bind(&done);
          }
        }
      }
    }
  
    // We don't support new.target and rest parameters here.
    DCHECK_NULL(info->scope()->new_target_var());
    DCHECK_NULL(info->scope()->rest_parameter());
    DCHECK_NULL(info->scope()->this_function_var());
  
    Variable* arguments = info->scope()->arguments();
    if (arguments != NULL) {
      // Function uses arguments object.
      Comment cmnt(masm_, "[ Allocate arguments object");
      if (!function_in_register_r3) {
        // Load this again, if it's used by the local context below.
        __ LoadP(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
      }
      if (is_strict(language_mode()) || !has_simple_parameters()) {
        Callable callable =
            Builtins::CallableFor(isolate(), Builtins::kFastNewStrictArguments);
        __ Call(callable.code(), RelocInfo::CODE_TARGET);
        RestoreContext();
      } else if (literal()->has_duplicate_parameters()) {
        __ Push(r3);
        __ CallRuntime(Runtime::kNewSloppyArguments_Generic);
      } else {
        Callable callable =
            Builtins::CallableFor(isolate(), Builtins::kFastNewSloppyArguments);
        __ Call(callable.code(), RelocInfo::CODE_TARGET);
        RestoreContext();
      }
  
      SetVar(arguments, r2, r3, r4);
    }
  
    if (FLAG_trace) {
      __ CallRuntime(Runtime::kTraceEnter);
    }
  
    // Visit the declarations and body.
    {
      Comment cmnt(masm_, "[ Declarations");
      VisitDeclarations(scope()->declarations());
    }
  
    // Assert that the declarations do not use ICs. Otherwise the debugger
    // won't be able to redirect a PC at an IC to the correct IC in newly
    // recompiled code.
    DCHECK_EQ(0, ic_total_count_);
  
    {
      Comment cmnt(masm_, "[ Stack check");
      Label ok;
      __ LoadRoot(ip, Heap::kStackLimitRootIndex);
      __ CmpLogicalP(sp, ip);
      __ bge(&ok, Label::kNear);
      __ Call(isolate()->builtins()->StackCheck(), RelocInfo::CODE_TARGET);
      __ bind(&ok);
    }
  
    {
      Comment cmnt(masm_, "[ Body");
      DCHECK(loop_depth() == 0);
      VisitStatements(literal()->body());
      DCHECK(loop_depth() == 0);
    }
  
    // Always emit a 'return undefined' in case control fell off the end of
    // the body.
    {
      Comment cmnt(masm_, "[ return <undefined>;");
      __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
    }
    EmitReturnSequence();
  }
  
  void FullCodeGenerator::ClearAccumulator() {
    __ LoadSmiLiteral(r2, Smi::kZero);
  }
  
  void FullCodeGenerator::EmitProfilingCounterDecrement(int delta) {
    __ mov(r4, Operand(profiling_counter_));
    intptr_t smi_delta = reinterpret_cast<intptr_t>(Smi::FromInt(delta));
    if (CpuFeatures::IsSupported(GENERAL_INSTR_EXT) && is_int8(-smi_delta)) {
      __ AddP(FieldMemOperand(r4, Cell::kValueOffset), Operand(-smi_delta));
      __ LoadP(r5, FieldMemOperand(r4, Cell::kValueOffset));
    } else {
      __ LoadP(r5, FieldMemOperand(r4, Cell::kValueOffset));
      __ SubSmiLiteral(r5, r5, Smi::FromInt(delta), r0);
      __ StoreP(r5, FieldMemOperand(r4, Cell::kValueOffset));
    }
  }
  
  void FullCodeGenerator::EmitProfilingCounterReset() {
    int reset_value = FLAG_interrupt_budget;
    __ mov(r4, Operand(profiling_counter_));
    __ LoadSmiLiteral(r5, Smi::FromInt(reset_value));
    __ StoreP(r5, FieldMemOperand(r4, Cell::kValueOffset));
  }
  
  void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
                                                  Label* back_edge_target) {
    Comment cmnt(masm_, "[ Back edge bookkeeping");
    Label ok;
  
    DCHECK(back_edge_target->is_bound());
    int distance = masm_->SizeOfCodeGeneratedSince(back_edge_target) +
                   kCodeSizeMultiplier / 2;
    int weight = Min(kMaxBackEdgeWeight, Max(1, distance / kCodeSizeMultiplier));
    EmitProfilingCounterDecrement(weight);
    {
      // BackEdgeTable::PatchAt manipulates this sequence.
      __ bge(&ok, Label::kNear);
      __ Call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
  
      // Record a mapping of this PC offset to the OSR id.  This is used to find
      // the AST id from the unoptimized code in order to use it as a key into
      // the deoptimization input data found in the optimized code.
      RecordBackEdge(stmt->OsrEntryId());
    }
    EmitProfilingCounterReset();
  
    __ bind(&ok);
  }
  
  void FullCodeGenerator::EmitProfilingCounterHandlingForReturnSequence(
      bool is_tail_call) {
    // Pretend that the exit is a backwards jump to the entry.
    int weight = 1;
    if (info_->ShouldSelfOptimize()) {
      weight = FLAG_interrupt_budget / FLAG_self_opt_count;
    } else {
      int distance = masm_->pc_offset() + kCodeSizeMultiplier / 2;
      weight = Min(kMaxBackEdgeWeight, Max(1, distance / kCodeSizeMultiplier));
    }
    EmitProfilingCounterDecrement(weight);
    Label ok;
    __ CmpP(r5, Operand::Zero());
    __ bge(&ok);
    // Don't need to save result register if we are going to do a tail call.
    if (!is_tail_call) {
      __ push(r2);
    }
    __ Call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
    if (!is_tail_call) {
      __ pop(r2);
    }
    EmitProfilingCounterReset();
    __ bind(&ok);
  }
  
  void FullCodeGenerator::EmitReturnSequence() {
    Comment cmnt(masm_, "[ Return sequence");
    if (return_label_.is_bound()) {
      __ b(&return_label_);
    } else {
      __ bind(&return_label_);
      if (FLAG_trace) {
        // Push the return value on the stack as the parameter.
        // Runtime::TraceExit returns its parameter in r2
        __ push(r2);
        __ CallRuntime(Runtime::kTraceExit);
      }
      EmitProfilingCounterHandlingForReturnSequence(false);
  
      // Make sure that the constant pool is not emitted inside of the return
      // sequence.
      {
        int32_t arg_count = info_->scope()->num_parameters() + 1;
        int32_t sp_delta = arg_count * kPointerSize;
        SetReturnPosition(literal());
        __ LeaveFrame(StackFrame::JAVA_SCRIPT, sp_delta);
  
        __ Ret();
      }
    }
  }
  
  void FullCodeGenerator::RestoreContext() {
    __ LoadP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  void FullCodeGenerator::StackValueContext::Plug(Variable* var) const {
    DCHECK(var->IsStackAllocated() || var->IsContextSlot());
    codegen()->GetVar(result_register(), var);
    codegen()->PushOperand(result_register());
  }
  
  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 {
    __ LoadRoot(result_register(), index);
    codegen()->PushOperand(result_register());
  }
  
  void FullCodeGenerator::TestContext::Plug(Heap::RootListIndex index) const {
    if (index == Heap::kUndefinedValueRootIndex ||
        index == Heap::kNullValueRootIndex ||
        index == Heap::kFalseValueRootIndex) {
      if (false_label_ != fall_through_) __ b(false_label_);
    } else if (index == Heap::kTrueValueRootIndex) {
      if (true_label_ != fall_through_) __ b(true_label_);
    } else {
      __ LoadRoot(result_register(), index);
      codegen()->DoTest(this);
    }
  }
  
  void FullCodeGenerator::EffectContext::Plug(Handle<Object> lit) const {}
  
  void FullCodeGenerator::AccumulatorValueContext::Plug(
      Handle<Object> lit) const {
    if (lit->IsHeapObject()) {
      __ mov(result_register(), Operand(Handle<HeapObject>::cast(lit)));
    } else {
      __ mov(result_register(), Operand(Smi::cast(*lit)));
    }
  }
  
  void FullCodeGenerator::StackValueContext::Plug(Handle<Object> lit) const {
    // Immediates cannot be pushed directly.
    if (lit->IsHeapObject()) {
      __ mov(result_register(), Operand(Handle<HeapObject>::cast(lit)));
    } else {
      __ mov(result_register(), Operand(Smi::cast(*lit)));
    }
    codegen()->PushOperand(result_register());
  }
  
  void FullCodeGenerator::TestContext::Plug(Handle<Object> lit) const {
    DCHECK(lit->IsNullOrUndefined(isolate()) || !lit->IsUndetectable());
    if (lit->IsNullOrUndefined(isolate()) || lit->IsFalse(isolate())) {
      if (false_label_ != fall_through_) __ b(false_label_);
    } else if (lit->IsTrue(isolate()) || lit->IsJSObject()) {
      if (true_label_ != fall_through_) __ b(true_label_);
    } else if (lit->IsString()) {
      if (String::cast(*lit)->length() == 0) {
        if (false_label_ != fall_through_) __ b(false_label_);
      } else {
        if (true_label_ != fall_through_) __ b(true_label_);
      }
    } else if (lit->IsSmi()) {
      if (Smi::ToInt(*lit) == 0) {
        if (false_label_ != fall_through_) __ b(false_label_);
      } else {
        if (true_label_ != fall_through_) __ b(true_label_);
      }
    } else {
      // For simplicity we always test the accumulator register.
      __ mov(result_register(), Operand(Handle<HeapObject>::cast(lit)));
      codegen()->DoTest(this);
    }
  }
  
  void FullCodeGenerator::StackValueContext::DropAndPlug(int count,
                                                         Register reg) const {
    DCHECK(count > 0);
    if (count > 1) codegen()->DropOperands(count - 1);
    __ StoreP(reg, MemOperand(sp, 0));
  }
  
  void FullCodeGenerator::EffectContext::Plug(Label* materialize_true,
                                              Label* materialize_false) const {
    DCHECK(materialize_true == materialize_false);
    __ bind(materialize_true);
  }
  
  void FullCodeGenerator::AccumulatorValueContext::Plug(
      Label* materialize_true, Label* materialize_false) const {
    Label done;
    __ bind(materialize_true);
    __ LoadRoot(result_register(), Heap::kTrueValueRootIndex);
    __ b(&done, Label::kNear);
    __ bind(materialize_false);
    __ LoadRoot(result_register(), Heap::kFalseValueRootIndex);
    __ bind(&done);
  }
  
  void FullCodeGenerator::StackValueContext::Plug(
      Label* materialize_true, Label* materialize_false) const {
    Label done;
    __ bind(materialize_true);
    __ LoadRoot(ip, Heap::kTrueValueRootIndex);
    __ b(&done, Label::kNear);
    __ bind(materialize_false);
    __ LoadRoot(ip, Heap::kFalseValueRootIndex);
    __ bind(&done);
    codegen()->PushOperand(ip);
  }
  
  void FullCodeGenerator::TestContext::Plug(Label* materialize_true,
                                            Label* materialize_false) const {
    DCHECK(materialize_true == true_label_);
    DCHECK(materialize_false == false_label_);
  }
  
  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;
    __ LoadRoot(ip, value_root_index);
    codegen()->PushOperand(ip);
  }
  
  void FullCodeGenerator::TestContext::Plug(bool flag) const {
    if (flag) {
      if (true_label_ != fall_through_) __ b(true_label_);
    } else {
      if (false_label_ != fall_through_) __ b(false_label_);
    }
  }
  
  void FullCodeGenerator::DoTest(Expression* condition, Label* if_true,
                                 Label* if_false, Label* fall_through) {
    Callable callable = Builtins::CallableFor(isolate(), Builtins::kToBoolean);
    __ Call(callable.code(), RelocInfo::CODE_TARGET);
    RestoreContext();
    __ CompareRoot(result_register(), Heap::kTrueValueRootIndex);
    Split(eq, if_true, if_false, fall_through);
  }
  
  void FullCodeGenerator::Split(Condition cond, Label* if_true, Label* if_false,
                                Label* fall_through) {
    if (if_false == fall_through) {
      __ b(cond, if_true);
    } else if (if_true == fall_through) {
      __ b(NegateCondition(cond), if_false);
    } else {
      __ b(cond, if_true);
      __ b(if_false);
    }
  }
  
  MemOperand FullCodeGenerator::StackOperand(Variable* var) {
    DCHECK(var->IsStackAllocated());
    // Offset is negative because higher indexes are at lower addresses.
    int offset = -var->index() * kPointerSize;
    // Adjust by a (parameter or local) base offset.
    if (var->IsParameter()) {
      offset += (info_->scope()->num_parameters() + 1) * kPointerSize;
    } else {
      offset += JavaScriptFrameConstants::kLocal0Offset;
    }
    return MemOperand(fp, offset);
  }
  
  MemOperand FullCodeGenerator::VarOperand(Variable* var, Register scratch) {
    DCHECK(var->IsContextSlot() || var->IsStackAllocated());
    if (var->IsContextSlot()) {
      int context_chain_length = scope()->ContextChainLength(var->scope());
      __ LoadContext(scratch, context_chain_length);
      return ContextMemOperand(scratch, var->index());
    } else {
      return StackOperand(var);
    }
  }
  
  void FullCodeGenerator::GetVar(Register dest, Variable* var) {
    // Use destination as scratch.
    MemOperand location = VarOperand(var, dest);
    __ LoadP(dest, location, r0);
  }
  
  void FullCodeGenerator::SetVar(Variable* var, Register src, Register scratch0,
                                 Register scratch1) {
    DCHECK(var->IsContextSlot() || var->IsStackAllocated());
    DCHECK(!scratch0.is(src));
    DCHECK(!scratch0.is(scratch1));
    DCHECK(!scratch1.is(src));
    MemOperand location = VarOperand(var, scratch0);
    __ StoreP(src, location);
  
    // Emit the write barrier code if the location is in the heap.
    if (var->IsContextSlot()) {
      __ RecordWriteContextSlot(scratch0, location.offset(), src, scratch1,
                                kLRHasBeenSaved, kDontSaveFPRegs);
    }
  }
  
  void FullCodeGenerator::EmitDebugCheckDeclarationContext(Variable* variable) {
    // The variable in the declaration always resides in the current function
    // context.
    DCHECK_EQ(0, scope()->ContextChainLength(variable->scope()));
    if (FLAG_debug_code) {
      // Check that we're not inside a with or catch context.
      __ LoadP(r3, FieldMemOperand(cp, HeapObject::kMapOffset));
      __ CompareRoot(r3, Heap::kWithContextMapRootIndex);
      __ Check(ne, kDeclarationInWithContext);
      __ CompareRoot(r3, Heap::kCatchContextMapRootIndex);
      __ Check(ne, kDeclarationInCatchContext);
    }
  }
  
  void FullCodeGenerator::VisitVariableDeclaration(
      VariableDeclaration* declaration) {
    VariableProxy* proxy = declaration->proxy();
    Variable* variable = proxy->var();
    switch (variable->location()) {
      case VariableLocation::UNALLOCATED: {
        DCHECK(!variable->binding_needs_init());
        globals_->Add(variable->name(), zone());
        FeedbackSlot slot = proxy->VariableFeedbackSlot();
        DCHECK(!slot.IsInvalid());
        globals_->Add(handle(Smi::FromInt(slot.ToInt()), isolate()), zone());
        globals_->Add(isolate()->factory()->undefined_value(), zone());
        globals_->Add(isolate()->factory()->undefined_value(), zone());
        break;
      }
      case VariableLocation::PARAMETER:
      case VariableLocation::LOCAL:
        if (variable->binding_needs_init()) {
          Comment cmnt(masm_, "[ VariableDeclaration");
          __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
          __ StoreP(ip, StackOperand(variable));
        }
        break;
  
      case VariableLocation::CONTEXT:
        if (variable->binding_needs_init()) {
          Comment cmnt(masm_, "[ VariableDeclaration");
          EmitDebugCheckDeclarationContext(variable);
          __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
          __ StoreP(ip, ContextMemOperand(cp, variable->index()));
          // No write barrier since the_hole_value is in old space.
        }
        break;
  
      case VariableLocation::LOOKUP:
      case VariableLocation::MODULE:
        UNREACHABLE();
    }
  }
  
  void FullCodeGenerator::VisitFunctionDeclaration(
      FunctionDeclaration* declaration) {
    VariableProxy* proxy = declaration->proxy();
    Variable* variable = proxy->var();
    switch (variable->location()) {
      case VariableLocation::UNALLOCATED: {
        globals_->Add(variable->name(), zone());
        FeedbackSlot slot = proxy->VariableFeedbackSlot();
        DCHECK(!slot.IsInvalid());
        globals_->Add(handle(Smi::FromInt(slot.ToInt()), isolate()), zone());
  
        // We need the slot where the literals array lives, too.
        slot = declaration->fun()->LiteralFeedbackSlot();
        DCHECK(!slot.IsInvalid());
        globals_->Add(handle(Smi::FromInt(slot.ToInt()), isolate()), zone());
  
        Handle<SharedFunctionInfo> function =
            Compiler::GetSharedFunctionInfo(declaration->fun(), script(), info_);
        // Check for stack-overflow exception.
        if (function.is_null()) return SetStackOverflow();
        globals_->Add(function, zone());
        break;
      }
  
      case VariableLocation::PARAMETER:
      case VariableLocation::LOCAL: {
        Comment cmnt(masm_, "[ FunctionDeclaration");
        VisitForAccumulatorValue(declaration->fun());
        __ StoreP(result_register(), StackOperand(variable));
        break;
      }
  
      case VariableLocation::CONTEXT: {
        Comment cmnt(masm_, "[ FunctionDeclaration");
        EmitDebugCheckDeclarationContext(variable);
        VisitForAccumulatorValue(declaration->fun());
        __ StoreP(result_register(), ContextMemOperand(cp, variable->index()));
        int offset = Context::SlotOffset(variable->index());
        // We know that we have written a function, which is not a smi.
        __ RecordWriteContextSlot(cp, offset, result_register(), r4,
                                  kLRHasBeenSaved, kDontSaveFPRegs,
                                  EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
        break;
      }
  
      case VariableLocation::LOOKUP:
      case VariableLocation::MODULE:
        UNREACHABLE();
    }
  }
  
  void FullCodeGenerator::DeclareGlobals(Handle<FixedArray> pairs) {
    // Call the runtime to declare the globals.
    __ mov(r3, Operand(pairs));
    __ LoadSmiLiteral(r2, Smi::FromInt(DeclareGlobalsFlags()));
    __ EmitLoadFeedbackVector(r4);
    __ Push(r3, r2, r4);
    __ CallRuntime(Runtime::kDeclareGlobals);
    // 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());
  
    ZoneList<CaseClause*>* clauses = stmt->cases();
    CaseClause* default_clause = NULL;  // Can occur anywhere in the list.
  
    Label next_test;  // Recycled for each test.
    // Compile all the tests with branches to their bodies.
    for (int i = 0; i < clauses->length(); i++) {
      CaseClause* clause = clauses->at(i);
      clause->body_target()->Unuse();
  
      // The default is not a test, but remember it as final fall through.
      if (clause->is_default()) {
        default_clause = clause;
        continue;
      }
  
      Comment cmnt(masm_, "[ Case comparison");
      __ bind(&next_test);
      next_test.Unuse();
  
      // Compile the label expression.
      VisitForAccumulatorValue(clause->label());
  
      // Perform the comparison as if via '==='.
      __ LoadP(r3, MemOperand(sp, 0));  // Switch value.
      bool inline_smi_code = ShouldInlineSmiCase(Token::EQ_STRICT);
      JumpPatchSite patch_site(masm_);
      if (inline_smi_code) {
        Label slow_case;
        __ LoadRR(r4, r2);
        __ OrP(r4, r3);
        patch_site.EmitJumpIfNotSmi(r4, &slow_case);
  
        __ CmpP(r3, r2);
        __ bne(&next_test);
        __ Drop(1);  // Switch value is no longer needed.
        __ b(clause->body_target());
        __ bind(&slow_case);
      }
  
      // Record position before stub call for type feedback.
      SetExpressionPosition(clause);
      Handle<Code> ic =
          CodeFactory::CompareIC(isolate(), Token::EQ_STRICT).code();
      CallIC(ic);
      patch_site.EmitPatchInfo();
  
      Label skip;
      __ b(&skip);
      __ CompareRoot(r2, Heap::kTrueValueRootIndex);
      __ bne(&next_test);
      __ Drop(1);
      __ b(clause->body_target());
      __ bind(&skip);
  
      __ CmpP(r2, Operand::Zero());
      __ bne(&next_test);
      __ Drop(1);  // Switch value is no longer needed.
      __ b(clause->body_target());
    }
  
    // Discard the test value and jump to the default if present, otherwise to
    // the end of the statement.
    __ bind(&next_test);
    DropOperands(1);  // Switch value is no longer needed.
    if (default_clause == NULL) {
      __ b(nested_statement.break_label());
    } else {
      __ b(default_clause->body_target());
    }
  
    // Compile all the case bodies.
    for (int i = 0; i < clauses->length(); i++) {
      Comment cmnt(masm_, "[ Case body");
      CaseClause* clause = clauses->at(i);
      __ bind(clause->body_target());
      VisitStatements(clause->statements());
    }
  
    __ bind(nested_statement.break_label());
  }
  
  void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
    Comment cmnt(masm_, "[ ForInStatement");
    SetStatementPosition(stmt, SKIP_BREAK);
  
    FeedbackSlot slot = stmt->ForInFeedbackSlot();
  
    // Get the object to enumerate over.
    SetExpressionAsStatementPosition(stmt->enumerable());
    VisitForAccumulatorValue(stmt->enumerable());
    OperandStackDepthIncrement(5);
  
    Label loop, exit;
    Iteration loop_statement(this, stmt);
    increment_loop_depth();
  
    // If the object is null or undefined, skip over the loop, otherwise convert
    // it to a JS receiver.  See ECMA-262 version 5, section 12.6.4.
    Label convert, done_convert;
    __ JumpIfSmi(r2, &convert);
    __ CompareObjectType(r2, r3, r3, FIRST_JS_RECEIVER_TYPE);
    __ bge(&done_convert);
    __ CompareRoot(r2, Heap::kNullValueRootIndex);
    __ beq(&exit);
    __ CompareRoot(r2, Heap::kUndefinedValueRootIndex);
    __ beq(&exit);
    __ bind(&convert);
    __ Call(isolate()->builtins()->ToObject(), RelocInfo::CODE_TARGET);
    RestoreContext();
    __ bind(&done_convert);
    __ push(r2);
  
    // Check cache validity in generated code. If we cannot guarantee cache
    // validity, call the runtime system to check cache validity or get the
    // property names in a fixed array. Note: Proxies never have an enum cache,
    // so will always take the slow path.
    Label call_runtime;
    __ CheckEnumCache(&call_runtime);
  
    // The enum cache is valid.  Load the map of the object being
    // iterated over and use the cache for the iteration.
    Label use_cache;
    __ LoadP(r2, FieldMemOperand(r2, HeapObject::kMapOffset));
    __ b(&use_cache);
  
    // Get the set of properties to enumerate.
    __ bind(&call_runtime);
    __ push(r2);  // Duplicate the enumerable object on the stack.
    __ CallRuntime(Runtime::kForInEnumerate);
  
    // If we got a map from the runtime call, we can do a fast
    // modification check. Otherwise, we got a fixed array, and we have
    // to do a slow check.
    Label fixed_array;
    __ LoadP(r4, FieldMemOperand(r2, HeapObject::kMapOffset));
    __ CompareRoot(r4, Heap::kMetaMapRootIndex);
    __ bne(&fixed_array);
  
    // We got a map in register r2. Get the enumeration cache from it.
    Label no_descriptors;
    __ bind(&use_cache);
  
    __ EnumLength(r3, r2);
    __ CmpSmiLiteral(r3, Smi::kZero, r0);
    __ beq(&no_descriptors, Label::kNear);
  
    __ LoadInstanceDescriptors(r2, r4);
    __ LoadP(r4, FieldMemOperand(r4, DescriptorArray::kEnumCacheBridgeOffset));
    __ LoadP(r4,
             FieldMemOperand(r4, DescriptorArray::kEnumCacheBridgeCacheOffset));
  
    // Set up the four remaining stack slots.
    __ push(r2);  // Map.
    __ LoadSmiLiteral(r2, Smi::kZero);
    // Push enumeration cache, enumeration cache length (as smi) and zero.
    __ Push(r4, r3, r2);
    __ b(&loop);
  
    __ bind(&no_descriptors);
    __ Drop(1);
    __ b(&exit);
  
    // We got a fixed array in register r2. Iterate through that.
    __ bind(&fixed_array);
  
    __ LoadSmiLiteral(r3, Smi::FromInt(1));  // Smi(1) indicates slow check
    __ Push(r3, r2);                         // Smi and array
    __ LoadP(r3, FieldMemOperand(r2, FixedArray::kLengthOffset));
    __ Push(r3);  // Fixed array length (as smi).
    __ LoadSmiLiteral(r2, Smi::kZero);
    __ Push(r2);  // Initial index.
  
    // Generate code for doing the condition check.
    __ bind(&loop);
    SetExpressionAsStatementPosition(stmt->each());
  
    // Load the current count to r2, load the length to r3.
    __ LoadP(r2, MemOperand(sp, 0 * kPointerSize));
    __ LoadP(r3, MemOperand(sp, 1 * kPointerSize));
    __ CmpLogicalP(r2, r3);  // Compare to the array length.
    __ bge(loop_statement.break_label());
  
    // Get the current entry of the array into register r5.
    __ LoadP(r4, MemOperand(sp, 2 * kPointerSize));
    __ AddP(r4, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
    __ SmiToPtrArrayOffset(r5, r2);
    __ LoadP(r5, MemOperand(r5, r4));
  
    // Get the expected map from the stack or a smi in the
    // permanent slow case into register r4.
    __ LoadP(r4, MemOperand(sp, 3 * kPointerSize));
  
    // Check if the expected map still matches that of the enumerable.
    // If not, we may have to filter the key.
    Label update_each;
    __ LoadP(r3, MemOperand(sp, 4 * kPointerSize));
    __ LoadP(r6, FieldMemOperand(r3, HeapObject::kMapOffset));
    __ CmpP(r6, r4);
    __ beq(&update_each);
  
    // We need to filter the key, record slow-path here.
    int const vector_index = SmiFromSlot(slot)->value();
    __ EmitLoadFeedbackVector(r2);
    __ mov(r4, Operand(FeedbackVector::MegamorphicSentinel(isolate())));
    __ StoreP(
        r4, FieldMemOperand(r2, FixedArray::OffsetOfElementAt(vector_index)), r0);
  
    // Convert the entry to a string or (smi) 0 if it isn't a property
    // any more. If the property has been removed while iterating, we
    // just skip it.
    __ Push(r3, r5);  // Enumerable and current entry.
    __ CallRuntime(Runtime::kForInFilter);
    __ LoadRR(r5, r2);
    __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
    __ CmpP(r2, r0);
    __ beq(loop_statement.continue_label());
  
    // Update the 'each' property or variable from the possibly filtered
    // entry in register r5.
    __ bind(&update_each);
    __ LoadRR(result_register(), r5);
    // Perform the assignment as if via '='.
    {
      EffectContext context(this);
      EmitAssignment(stmt->each(), stmt->EachFeedbackSlot());
    }
  
    // Generate code for the body of the loop.
    Visit(stmt->body());
  
    // Generate code for the going to the next element by incrementing
    // the index (smi) stored on top of the stack.
    __ bind(loop_statement.continue_label());
    __ pop(r2);
    __ AddSmiLiteral(r2, r2, Smi::FromInt(1), r0);
    __ push(r2);
  
    EmitBackEdgeBookkeeping(stmt, &loop);
    __ b(&loop);
  
    // Remove the pointers stored on the stack.
    __ bind(loop_statement.break_label());
    DropOperands(5);
  
    // Exit and decrement the loop depth.
    __ bind(&exit);
    decrement_loop_depth();
  }
  
  void FullCodeGenerator::EmitSetHomeObject(Expression* initializer, int offset,
                                            FeedbackSlot slot) {
    DCHECK(NeedsHomeObject(initializer));
    __ LoadP(StoreDescriptor::ReceiverRegister(), MemOperand(sp));
    __ LoadP(StoreDescriptor::ValueRegister(),
             MemOperand(sp, offset * kPointerSize));
    CallStoreIC(slot, isolate()->factory()->home_object_symbol());
  }
  
  void FullCodeGenerator::EmitSetHomeObjectAccumulator(Expression* initializer,
                                                       int offset,
                                                       FeedbackSlot slot) {
    DCHECK(NeedsHomeObject(initializer));
    __ Move(StoreDescriptor::ReceiverRegister(), r2);
    __ LoadP(StoreDescriptor::ValueRegister(),
             MemOperand(sp, offset * kPointerSize));
    CallStoreIC(slot, isolate()->factory()->home_object_symbol());
  }
  
  void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy,
                                           TypeofMode typeof_mode) {
    // Record position before possible IC call.
    SetExpressionPosition(proxy);
    Variable* var = proxy->var();
  
    // Two cases: global variables and all other types of variables.
    switch (var->location()) {
      case VariableLocation::UNALLOCATED: {
        Comment cmnt(masm_, "[ Global variable");
        EmitGlobalVariableLoad(proxy, typeof_mode);
        context()->Plug(r2);
        break;
      }
  
      case VariableLocation::PARAMETER:
      case VariableLocation::LOCAL:
      case VariableLocation::CONTEXT: {
        DCHECK_EQ(NOT_INSIDE_TYPEOF, typeof_mode);
        Comment cmnt(masm_, var->IsContextSlot() ? "[ Context variable"
                                                 : "[ Stack variable");
        if (proxy->hole_check_mode() == HoleCheckMode::kRequired) {
          // Throw a reference error when using an uninitialized let/const
          // binding in harmony mode.
          Label done;
          GetVar(r2, var);
          __ CompareRoot(r2, Heap::kTheHoleValueRootIndex);
          __ bne(&done);
          __ mov(r2, Operand(var->name()));
          __ push(r2);
          __ CallRuntime(Runtime::kThrowReferenceError);
          __ bind(&done);
          context()->Plug(r2);
          break;
        }
        context()->Plug(var);
        break;
      }
  
      case VariableLocation::LOOKUP:
      case VariableLocation::MODULE:
        UNREACHABLE();
    }
  }
  
  void FullCodeGenerator::EmitAccessor(ObjectLiteralProperty* property) {
    Expression* expression = (property == NULL) ? NULL : property->value();
    if (expression == NULL) {
      __ LoadRoot(r3, Heap::kNullValueRootIndex);
      PushOperand(r3);
    } else {
      VisitForStackValue(expression);
      if (NeedsHomeObject(expression)) {
        DCHECK(property->kind() == ObjectLiteral::Property::GETTER ||
               property->kind() == ObjectLiteral::Property::SETTER);
        int offset = property->kind() == ObjectLiteral::Property::GETTER ? 2 : 3;
        EmitSetHomeObject(expression, offset, property->GetSlot());
      }
    }
  }
  
  void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
    Comment cmnt(masm_, "[ ObjectLiteral");
  
    Handle<BoilerplateDescription> constant_properties =
        expr->GetOrBuildConstantProperties(isolate());
    __ LoadP(r5, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
    __ LoadSmiLiteral(r4, SmiFromSlot(expr->literal_slot()));
    __ mov(r3, Operand(constant_properties));
    int flags = expr->ComputeFlags();
    __ LoadSmiLiteral(r2, Smi::FromInt(flags));
    if (MustCreateObjectLiteralWithRuntime(expr)) {
      __ Push(r5, r4, r3, r2);
      __ CallRuntime(Runtime::kCreateObjectLiteral);
    } else {
      Callable callable =
          Builtins::CallableFor(isolate(), Builtins::kFastCloneShallowObject);
      __ Call(callable.code(), RelocInfo::CODE_TARGET);
      RestoreContext();
    }
  
    // If result_saved is true the result is on top of the stack.  If
    // result_saved is false the result is in r2.
    bool result_saved = false;
  
    AccessorTable accessor_table(zone());
    for (int i = 0; i < expr->properties()->length(); i++) {
      ObjectLiteral::Property* property = expr->properties()->at(i);
      DCHECK(!property->is_computed_name());
      if (property->IsCompileTimeValue()) continue;
  
      Literal* key = property->key()->AsLiteral();
      Expression* value = property->value();
      if (!result_saved) {
        PushOperand(r2);  // Save result on stack
        result_saved = true;
      }
      switch (property->kind()) {
        case ObjectLiteral::Property::SPREAD:
        case ObjectLiteral::Property::CONSTANT:
          UNREACHABLE();
        case ObjectLiteral::Property::MATERIALIZED_LITERAL:
          DCHECK(!CompileTimeValue::IsCompileTimeValue(property->value()));
        // Fall through.
        case ObjectLiteral::Property::COMPUTED:
          // It is safe to use [[Put]] here because the boilerplate already
          // contains computed properties with an uninitialized value.
          if (key->IsStringLiteral()) {
            DCHECK(key->IsPropertyName());
            if (property->emit_store()) {
              VisitForAccumulatorValue(value);
              DCHECK(StoreDescriptor::ValueRegister().is(r2));
              __ LoadP(StoreDescriptor::ReceiverRegister(), MemOperand(sp));
              CallStoreIC(property->GetSlot(0), key->value(), kStoreOwn);
  
              if (NeedsHomeObject(value)) {
                EmitSetHomeObjectAccumulator(value, 0, property->GetSlot(1));
              }
            } else {
              VisitForEffect(value);
            }
            break;
          }
          // Duplicate receiver on stack.
          __ LoadP(r2, MemOperand(sp));
          PushOperand(r2);
          VisitForStackValue(key);
          VisitForStackValue(value);
          if (property->emit_store()) {
            if (NeedsHomeObject(value)) {
              EmitSetHomeObject(value, 2, property->GetSlot());
            }
            __ LoadSmiLiteral(r2, Smi::FromInt(SLOPPY));  // PropertyAttributes
            PushOperand(r2);
            CallRuntimeWithOperands(Runtime::kSetProperty);
          } else {
            DropOperands(3);
          }
          break;
        case ObjectLiteral::Property::PROTOTYPE:
          // Duplicate receiver on stack.
          __ LoadP(r2, MemOperand(sp));
          PushOperand(r2);
          VisitForStackValue(value);
          DCHECK(property->emit_store());
          CallRuntimeWithOperands(Runtime::kInternalSetPrototype);
          break;
        case ObjectLiteral::Property::GETTER:
          if (property->emit_store()) {
            AccessorTable::Iterator it = accessor_table.lookup(key);
            it->second->getter = property;
          }
          break;
        case ObjectLiteral::Property::SETTER:
          if (property->emit_store()) {
            AccessorTable::Iterator it = accessor_table.lookup(key);
            it->second->setter = property;
          }
          break;
      }
    }
  
    // Emit code to define accessors, using only a single call to the runtime for
    // each pair of corresponding getters and setters.
    for (AccessorTable::Iterator it = accessor_table.begin();
         it != accessor_table.end(); ++it) {
      __ LoadP(r2, MemOperand(sp));  // Duplicate receiver.
      PushOperand(r2);
      VisitForStackValue(it->first);
      EmitAccessor(it->second->getter);
      EmitAccessor(it->second->setter);
      __ LoadSmiLiteral(r2, Smi::FromInt(NONE));
      PushOperand(r2);
      CallRuntimeWithOperands(Runtime::kDefineAccessorPropertyUnchecked);
    }
  
    if (result_saved) {
      context()->PlugTOS();
    } else {
      context()->Plug(r2);
    }
  }
  
  void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
    Comment cmnt(masm_, "[ ArrayLiteral");
  
    Handle<ConstantElementsPair> constant_elements =
        expr->GetOrBuildConstantElements(isolate());
  
    __ LoadP(r5, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
    __ LoadSmiLiteral(r4, SmiFromSlot(expr->literal_slot()));
    __ mov(r3, Operand(constant_elements));
    if (MustCreateArrayLiteralWithRuntime(expr)) {
      __ LoadSmiLiteral(r2, Smi::FromInt(expr->ComputeFlags()));
      __ Push(r5, r4, r3, r2);
      __ CallRuntime(Runtime::kCreateArrayLiteral);
    } else {
      Callable callable =
          CodeFactory::FastCloneShallowArray(isolate(), TRACK_ALLOCATION_SITE);
      __ Call(callable.code(), RelocInfo::CODE_TARGET);
      RestoreContext();
    }
  
    bool result_saved = false;  // Is the result saved to the stack?
    ZoneList<Expression*>* subexprs = expr->values();
    int length = subexprs->length();
  
    // Emit code to evaluate all the non-constant subexpressions and to store
    // them into the newly cloned array.
    for (int array_index = 0; array_index < length; array_index++) {
      Expression* subexpr = subexprs->at(array_index);
      DCHECK(!subexpr->IsSpread());
      // If the subexpression is a literal or a simple materialized literal it
      // is already set in the cloned array.
      if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;
  
      if (!result_saved) {
        PushOperand(r2);
        result_saved = true;
      }
      VisitForAccumulatorValue(subexpr);
  
      __ LoadSmiLiteral(StoreDescriptor::NameRegister(),
                        Smi::FromInt(array_index));
      __ LoadP(StoreDescriptor::ReceiverRegister(), MemOperand(sp, 0));
      CallKeyedStoreIC(expr->LiteralFeedbackSlot());
    }
  
    if (result_saved) {
      context()->PlugTOS();
    } else {
      context()->Plug(r2);
    }
  }
  
  void FullCodeGenerator::VisitAssignment(Assignment* expr) {
    DCHECK(expr->target()->IsValidReferenceExpressionOrThis());
  
    Comment cmnt(masm_, "[ Assignment");
  
    Property* property = expr->target()->AsProperty();
    LhsKind assign_type = Property::GetAssignType(property);
  
    // Evaluate LHS expression.
    switch (assign_type) {
      case VARIABLE:
        // Nothing to do here.
        break;
      case NAMED_PROPERTY:
        if (expr->is_compound()) {
          // We need the receiver both on the stack and in the register.
          VisitForStackValue(property->obj());
          __ LoadP(LoadDescriptor::ReceiverRegister(), MemOperand(sp, 0));
        } else {
          VisitForStackValue(property->obj());
        }
        break;
      case KEYED_PROPERTY:
        if (expr->is_compound()) {
          VisitForStackValue(property->obj());
          VisitForStackValue(property->key());
          __ LoadP(LoadDescriptor::ReceiverRegister(),
                   MemOperand(sp, 1 * kPointerSize));
          __ LoadP(LoadDescriptor::NameRegister(), MemOperand(sp, 0));
        } else {
          VisitForStackValue(property->obj());
          VisitForStackValue(property->key());
        }
        break;
      case NAMED_SUPER_PROPERTY:
      case KEYED_SUPER_PROPERTY:
        UNREACHABLE();
        break;
    }
  
    // For compound assignments we need another deoptimization point after the
    // variable/property load.
    if (expr->is_compound()) {
      {
        AccumulatorValueContext context(this);
        switch (assign_type) {
          case VARIABLE:
            EmitVariableLoad(expr->target()->AsVariableProxy());
            break;
          case NAMED_PROPERTY:
            EmitNamedPropertyLoad(property);
            break;
          case KEYED_PROPERTY:
            EmitKeyedPropertyLoad(property);
            break;
          case NAMED_SUPER_PROPERTY:
          case KEYED_SUPER_PROPERTY:
            UNREACHABLE();
            break;
        }
      }
  
      Token::Value op = expr->binary_op();
      PushOperand(r2);  // Left operand goes on the stack.
      VisitForAccumulatorValue(expr->value());
  
      AccumulatorValueContext context(this);
      EmitBinaryOp(expr->binary_operation(), op);
    } else {
      VisitForAccumulatorValue(expr->value());
    }
  
    SetExpressionPosition(expr);
  
    // Store the value.
    switch (assign_type) {
      case VARIABLE: {
        VariableProxy* proxy = expr->target()->AsVariableProxy();
        EmitVariableAssignment(proxy->var(), expr->op(), expr->AssignmentSlot(),
                               proxy->hole_check_mode());
        context()->Plug(r2);
        break;
      }
      case NAMED_PROPERTY:
        EmitNamedPropertyAssignment(expr);
        break;
      case KEYED_PROPERTY:
        EmitKeyedPropertyAssignment(expr);
        break;
      case NAMED_SUPER_PROPERTY:
      case KEYED_SUPER_PROPERTY:
        UNREACHABLE();
        break;
    }
  }
  
  void FullCodeGenerator::PushOperands(Register reg1, Register reg2) {
    OperandStackDepthIncrement(2);
    __ Push(reg1, reg2);
  }
  
  void FullCodeGenerator::PushOperands(Register reg1, Register reg2,
                                       Register reg3) {
    OperandStackDepthIncrement(3);
    __ Push(reg1, reg2, reg3);
  }
  
  void FullCodeGenerator::PushOperands(Register reg1, Register reg2,
                                       Register reg3, Register reg4) {
    OperandStackDepthIncrement(4);
    __ Push(reg1, reg2, reg3, reg4);
  }
  
  void FullCodeGenerator::PopOperands(Register reg1, Register reg2) {
    OperandStackDepthDecrement(2);
    __ Pop(reg1, reg2);
  }
  
  void FullCodeGenerator::EmitOperandStackDepthCheck() {
    if (FLAG_debug_code) {
      int expected_diff = StandardFrameConstants::kFixedFrameSizeFromFp +
                          operand_stack_depth_ * kPointerSize;
      __ SubP(r2, fp, sp);
      __ CmpP(r2, Operand(expected_diff));
      __ Assert(eq, kUnexpectedStackDepth);
    }
  }
  
  void FullCodeGenerator::EmitBinaryOp(BinaryOperation* expr, Token::Value op) {
    PopOperand(r3);
    Handle<Code> code = CodeFactory::BinaryOperation(isolate(), op).code();
    __ Call(code, RelocInfo::CODE_TARGET);
    RestoreContext();
    context()->Plug(r2);
  }
  
  void FullCodeGenerator::EmitAssignment(Expression* expr, FeedbackSlot slot) {
    DCHECK(expr->IsValidReferenceExpressionOrThis());
  
    Property* prop = expr->AsProperty();
    LhsKind assign_type = Property::GetAssignType(prop);
  
    switch (assign_type) {
      case VARIABLE: {
        VariableProxy* proxy = expr->AsVariableProxy();
        EffectContext context(this);
        EmitVariableAssignment(proxy->var(), Token::ASSIGN, slot,
                               proxy->hole_check_mode());
        break;
      }
      case NAMED_PROPERTY: {
        PushOperand(r2);  // Preserve value.
        VisitForAccumulatorValue(prop->obj());
        __ Move(StoreDescriptor::ReceiverRegister(), r2);
        PopOperand(StoreDescriptor::ValueRegister());  // Restore value.
        CallStoreIC(slot, prop->key()->AsLiteral()->value());
        break;
      }
      case KEYED_PROPERTY: {
        PushOperand(r2);  // Preserve value.
        VisitForStackValue(prop->obj());
        VisitForAccumulatorValue(prop->key());
        __ Move(StoreDescriptor::NameRegister(), r2);
        PopOperands(StoreDescriptor::ValueRegister(),
                    StoreDescriptor::ReceiverRegister());
        CallKeyedStoreIC(slot);
        break;
      }
      case NAMED_SUPER_PROPERTY:
      case KEYED_SUPER_PROPERTY:
        UNREACHABLE();
        break;
    }
    context()->Plug(r2);
  }
  
  void FullCodeGenerator::EmitStoreToStackLocalOrContextSlot(
      Variable* var, MemOperand location) {
    __ StoreP(result_register(), location);
    if (var->IsContextSlot()) {
      // RecordWrite may destroy all its register arguments.
      __ LoadRR(r5, result_register());
      int offset = Context::SlotOffset(var->index());
      __ RecordWriteContextSlot(r3, offset, r5, r4, kLRHasBeenSaved,
                                kDontSaveFPRegs);
    }
  }
  
  void FullCodeGenerator::EmitVariableAssignment(Variable* var, Token::Value op,
                                                 FeedbackSlot slot,
                                                 HoleCheckMode hole_check_mode) {
    if (var->IsUnallocated()) {
      // Global var, const, or let.
      __ LoadGlobalObject(StoreDescriptor::ReceiverRegister());
      CallStoreIC(slot, var->name(), kStoreGlobal);
  
    } else if (IsLexicalVariableMode(var->mode()) && op != Token::INIT) {
      // Non-initializing assignment to let variable needs a write barrier.
      DCHECK(!var->IsLookupSlot());
      DCHECK(var->IsStackAllocated() || var->IsContextSlot());
      MemOperand location = VarOperand(var, r3);
      // Perform an initialization check for lexically declared variables.
      if (hole_check_mode == HoleCheckMode::kRequired) {
        Label assign;
        __ LoadP(r5, location);
        __ CompareRoot(r5, Heap::kTheHoleValueRootIndex);
        __ bne(&assign);
        __ mov(r5, Operand(var->name()));
        __ push(r5);
        __ CallRuntime(Runtime::kThrowReferenceError);
        __ bind(&assign);
      }
      if (var->mode() != CONST) {
        EmitStoreToStackLocalOrContextSlot(var, location);
      } else if (var->throw_on_const_assignment(language_mode())) {
        __ CallRuntime(Runtime::kThrowConstAssignError);
      }
    } else if (var->is_this() && var->mode() == CONST && op == Token::INIT) {
      // Initializing assignment to const {this} needs a write barrier.
      DCHECK(var->IsStackAllocated() || var->IsContextSlot());
      Label uninitialized_this;
      MemOperand location = VarOperand(var, r3);
      __ LoadP(r5, location);
      __ CompareRoot(r5, Heap::kTheHoleValueRootIndex);
      __ beq(&uninitialized_this);
      __ mov(r3, Operand(var->name()));
      __ push(r3);
      __ CallRuntime(Runtime::kThrowReferenceError);
      __ bind(&uninitialized_this);
      EmitStoreToStackLocalOrContextSlot(var, location);
    } else {
      DCHECK(var->mode() != CONST || op == Token::INIT);
      DCHECK((var->IsStackAllocated() || var->IsContextSlot()));
      DCHECK(!var->IsLookupSlot());
      // Assignment to var or initializing assignment to let/const in harmony
      // mode.
      MemOperand location = VarOperand(var, r3);
      EmitStoreToStackLocalOrContextSlot(var, location);
    }
  }
  
  void FullCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) {
    // Assignment to a property, using a named store IC.
    Property* prop = expr->target()->AsProperty();
    DCHECK(prop != NULL);
    DCHECK(prop->key()->IsLiteral());
  
    PopOperand(StoreDescriptor::ReceiverRegister());
    CallStoreIC(expr->AssignmentSlot(), prop->key()->AsLiteral()->value());
  
    context()->Plug(r2);
  }
  
  void FullCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) {
    // Assignment to a property, using a keyed store IC.
    PopOperands(StoreDescriptor::ReceiverRegister(),
                StoreDescriptor::NameRegister());
    DCHECK(StoreDescriptor::ValueRegister().is(r2));
  
    CallKeyedStoreIC(expr->AssignmentSlot());
  
    context()->Plug(r2);
  }
  
  // Code common for calls using the IC.
  void FullCodeGenerator::EmitCallWithLoadIC(Call* expr) {
    Expression* callee = expr->expression();
  
    // Get the target function.
    ConvertReceiverMode convert_mode;
    if (callee->IsVariableProxy()) {
      {
        StackValueContext context(this);
        EmitVariableLoad(callee->AsVariableProxy());
      }
      // Push undefined as receiver. This is patched in the method prologue if it
      // is a sloppy mode method.
      __ LoadRoot(r1, Heap::kUndefinedValueRootIndex);
      PushOperand(r1);
      convert_mode = ConvertReceiverMode::kNullOrUndefined;
    } else {
      // Load the function from the receiver.
      DCHECK(callee->IsProperty());
      DCHECK(!callee->AsProperty()->IsSuperAccess());
      __ LoadP(LoadDescriptor::ReceiverRegister(), MemOperand(sp, 0));
      EmitNamedPropertyLoad(callee->AsProperty());
      // Push the target function under the receiver.
      __ LoadP(r1, MemOperand(sp, 0));
      PushOperand(r1);
      __ StoreP(r2, MemOperand(sp, kPointerSize));
      convert_mode = ConvertReceiverMode::kNotNullOrUndefined;
    }
  
    EmitCall(expr, convert_mode);
  }
  
  // Code common for calls using the IC.
  void FullCodeGenerator::EmitKeyedCallWithLoadIC(Call* expr, Expression* key) {
    // Load the key.
    VisitForAccumulatorValue(key);
  
    Expression* callee = expr->expression();
  
    // Load the function from the receiver.
    DCHECK(callee->IsProperty());
    __ LoadP(LoadDescriptor::ReceiverRegister(), MemOperand(sp, 0));
    __ Move(LoadDescriptor::NameRegister(), r2);
    EmitKeyedPropertyLoad(callee->AsProperty());
  
    // Push the target function under the receiver.
    __ LoadP(ip, MemOperand(sp, 0));
    PushOperand(ip);
    __ StoreP(r2, MemOperand(sp, kPointerSize));
  
    EmitCall(expr, ConvertReceiverMode::kNotNullOrUndefined);
  }
  
  void FullCodeGenerator::EmitCall(Call* expr, ConvertReceiverMode mode) {
    // Load the arguments.
    ZoneList<Expression*>* args = expr->arguments();
    int arg_count = args->length();
    for (int i = 0; i < arg_count; i++) {
      VisitForStackValue(args->at(i));
    }
    SetCallPosition(expr);
    Handle<Code> code = CodeFactory::CallICTrampoline(isolate(), mode).code();
    __ Load(r5, Operand(IntFromSlot(expr->CallFeedbackICSlot())));
    __ LoadP(r3, MemOperand(sp, (arg_count + 1) * kPointerSize), r0);
    __ mov(r2, Operand(arg_count));
    CallIC(code);
    OperandStackDepthDecrement(arg_count + 1);
  
    RestoreContext();
    context()->DropAndPlug(1, r2);
  }
  
  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.
    DCHECK(!expr->expression()->IsSuperPropertyReference());
    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.
    SetConstructCallPosition(expr);
  
    // Load function and argument count into r3 and r2.
    __ mov(r2, Operand(arg_count));
    __ LoadP(r3, MemOperand(sp, arg_count * kPointerSize), r0);
  
    // Record call targets in unoptimized code.
    __ EmitLoadFeedbackVector(r4);
    __ LoadSmiLiteral(r5, SmiFromSlot(expr->CallNewFeedbackSlot()));
  
    CallConstructStub stub(isolate());
    CallIC(stub.GetCode());
    OperandStackDepthDecrement(arg_count + 1);
    RestoreContext();
    context()->Plug(r2);
  }
  
  void FullCodeGenerator::EmitIsSmi(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false, skip_lookup;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
                           &if_false, &fall_through);
  
    __ TestIfSmi(r2);
    Split(eq, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  void FullCodeGenerator::EmitIsJSReceiver(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
                           &if_false, &fall_through);
  
    __ JumpIfSmi(r2, if_false);
    __ CompareObjectType(r2, r3, r3, FIRST_JS_RECEIVER_TYPE);
    Split(ge, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
                           &if_false, &fall_through);
  
    __ JumpIfSmi(r2, if_false);
    __ CompareObjectType(r2, r3, r3, JS_ARRAY_TYPE);
    Split(eq, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  void FullCodeGenerator::EmitIsTypedArray(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
                           &if_false, &fall_through);
  
    __ JumpIfSmi(r2, if_false);
    __ CompareObjectType(r2, r3, r3, JS_TYPED_ARRAY_TYPE);
    Split(eq, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  void FullCodeGenerator::EmitIsJSProxy(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
  
    VisitForAccumulatorValue(args->at(0));
  
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
                           &if_false, &fall_through);
  
    __ JumpIfSmi(r2, if_false);
    __ CompareObjectType(r2, r3, r3, JS_PROXY_TYPE);
    Split(eq, if_true, if_false, fall_through);
  
    context()->Plug(if_true, if_false);
  }
  
  void FullCodeGenerator::EmitClassOf(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 1);
    Label done, null, function, non_function_constructor;
  
    VisitForAccumulatorValue(args->at(0));
  
    // If the object is not a JSReceiver, we return null.
    __ JumpIfSmi(r2, &null);
    STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
    __ CompareObjectType(r2, r2, r3, FIRST_JS_RECEIVER_TYPE);
    // Map is now in r2.
    __ blt(&null);
  
    // Return 'Function' for JSFunction and JSBoundFunction objects.
    __ CmpLogicalP(r3, Operand(FIRST_FUNCTION_TYPE));
    STATIC_ASSERT(LAST_FUNCTION_TYPE == LAST_TYPE);
    __ bge(&function);
  
    // Check if the constructor in the map is a JS function.
    Register instance_type = r4;
    __ GetMapConstructor(r2, r2, r3, instance_type);
    __ CmpP(instance_type, Operand(JS_FUNCTION_TYPE));
    __ bne(&non_function_constructor, Label::kNear);
  
    // r2 now contains the constructor function. Grab the
    // instance class name from there.
    __ LoadP(r2, FieldMemOperand(r2, JSFunction::kSharedFunctionInfoOffset));
    __ LoadP(r2,
             FieldMemOperand(r2, SharedFunctionInfo::kInstanceClassNameOffset));
    __ b(&done, Label::kNear);
  
    // Functions have class 'Function'.
    __ bind(&function);
    __ LoadRoot(r2, Heap::kFunction_stringRootIndex);
    __ b(&done, Label::kNear);
  
    // Objects with a non-function constructor have class 'Object'.
    __ bind(&non_function_constructor);
    __ LoadRoot(r2, Heap::kObject_stringRootIndex);
    __ b(&done, Label::kNear);
  
    // Non-JS objects have class null.
    __ bind(&null);
    __ LoadRoot(r2, Heap::kNullValueRootIndex);
  
    // All done.
    __ bind(&done);
  
    context()->Plug(r2);
  }
  
  void FullCodeGenerator::EmitStringCharCodeAt(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK(args->length() == 2);
    VisitForStackValue(args->at(0));
    VisitForAccumulatorValue(args->at(1));
  
    Register object = r3;
    Register index = r2;
    Register result = r5;
  
    PopOperand(object);
  
    Label need_conversion;
    Label index_out_of_range;
    Label done;
    StringCharCodeAtGenerator generator(object, index, result, &need_conversion,
                                        &need_conversion, &index_out_of_range);
    generator.GenerateFast(masm_);
    __ b(&done);
  
    __ bind(&index_out_of_range);
    // When the index is out of range, the spec requires us to return
    // NaN.
    __ LoadRoot(result, Heap::kNanValueRootIndex);
    __ b(&done);
  
    __ bind(&need_conversion);
    // Load the undefined value into the result register, which will
    // trigger conversion.
    __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
    __ b(&done);
  
    NopRuntimeCallHelper call_helper;
    generator.GenerateSlow(masm_, NOT_PART_OF_IC_HANDLER, call_helper);
  
    __ bind(&done);
    context()->Plug(result);
  }
  
  void FullCodeGenerator::EmitCall(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK_LE(2, args->length());
    // Push target, receiver and arguments onto the stack.
    for (Expression* const arg : *args) {
      VisitForStackValue(arg);
    }
    // Move target to r3.
    int const argc = args->length() - 2;
    __ LoadP(r3, MemOperand(sp, (argc + 1) * kPointerSize));
    // Call the target.
    __ mov(r2, Operand(argc));
    __ Call(isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
    OperandStackDepthDecrement(argc + 1);
    RestoreContext();
    // Discard the function left on TOS.
    context()->DropAndPlug(1, r2);
  }
  
  void FullCodeGenerator::EmitGetSuperConstructor(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    DCHECK_EQ(1, args->length());
    VisitForAccumulatorValue(args->at(0));
    __ AssertFunction(r2);
    __ LoadP(r2, FieldMemOperand(r2, HeapObject::kMapOffset));
    __ LoadP(r2, FieldMemOperand(r2, Map::kPrototypeOffset));
    context()->Plug(r2);
  }
  
  void FullCodeGenerator::EmitDebugIsActive(CallRuntime* expr) {
    DCHECK(expr->arguments()->length() == 0);
    ExternalReference debug_is_active =
        ExternalReference::debug_is_active_address(isolate());
    __ mov(ip, Operand(debug_is_active));
    __ LoadlB(r2, MemOperand(ip));
    __ SmiTag(r2);
    context()->Plug(r2);
  }
  
  void FullCodeGenerator::EmitLoadJSRuntimeFunction(CallRuntime* expr) {
    // Push function.
    __ LoadNativeContextSlot(expr->context_index(), r2);
    PushOperand(r2);
  
    // Push undefined as the receiver.
    __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
    PushOperand(r2);
  }
  
  void FullCodeGenerator::EmitCallJSRuntimeFunction(CallRuntime* expr) {
    ZoneList<Expression*>* args = expr->arguments();
    int arg_count = args->length();
  
    SetCallPosition(expr);
    __ LoadP(r3, MemOperand(sp, (arg_count + 1) * kPointerSize), r0);
    __ mov(r2, Operand(arg_count));
    __ Call(isolate()->builtins()->Call(ConvertReceiverMode::kNullOrUndefined),
            RelocInfo::CODE_TARGET);
    OperandStackDepthDecrement(arg_count + 1);
    RestoreContext();
  }
  
  void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
    switch (expr->op()) {
      case Token::DELETE: {
        Comment cmnt(masm_, "[ UnaryOperation (DELETE)");
        Property* property = expr->expression()->AsProperty();
        VariableProxy* proxy = expr->expression()->AsVariableProxy();
  
        if (property != NULL) {
          VisitForStackValue(property->obj());
          VisitForStackValue(property->key());
          PushOperand(Smi::FromInt(language_mode()));
          CallRuntimeWithOperands(Runtime::kDeleteProperty);
          context()->Plug(r2);
        } else if (proxy != NULL) {
          Variable* var = proxy->var();
          // Delete of an unqualified identifier is disallowed in strict mode but
          // "delete this" is allowed.
          bool is_this = var->is_this();
          DCHECK(is_sloppy(language_mode()) || is_this);
          if (var->IsUnallocated()) {
            __ LoadGlobalObject(r4);
            __ mov(r3, Operand(var->name()));
            __ Push(r4, r3);
            __ Push(Smi::FromInt(SLOPPY));
            __ CallRuntime(Runtime::kDeleteProperty);
            context()->Plug(r2);
          } else {
            DCHECK(!var->IsLookupSlot());
            DCHECK(var->IsStackAllocated() || var->IsContextSlot());
            // Result of deleting non-global, non-dynamic variables is false.
            // The subexpression does not have side effects.
            context()->Plug(is_this);
          }
        } else {
          // Result of deleting non-property, non-variable reference is true.
          // The subexpression may have side effects.
          VisitForEffect(expr->expression());
          context()->Plug(true);
        }
        break;
      }
  
      case Token::VOID: {
        Comment cmnt(masm_, "[ UnaryOperation (VOID)");
        VisitForEffect(expr->expression());
        context()->Plug(Heap::kUndefinedValueRootIndex);
        break;
      }
  
      case Token::NOT: {
        Comment cmnt(masm_, "[ UnaryOperation (NOT)");
        if (context()->IsEffect()) {
          // Unary NOT has no side effects so it's only necessary to visit the
          // subexpression.  Match the optimizing compiler by not branching.
          VisitForEffect(expr->expression());
        } else if (context()->IsTest()) {
          const TestContext* test = TestContext::cast(context());
          // The labels are swapped for the recursive call.
          VisitForControl(expr->expression(), test->false_label(),
                          test->true_label(), test->fall_through());
          context()->Plug(test->true_label(), test->false_label());
        } else {
          // We handle value contexts explicitly rather than simply visiting
          // for control and plugging the control flow into the context,
          // because we need to prepare a pair of extra administrative AST ids
          // for the optimizing compiler.
          DCHECK(context()->IsAccumulatorValue() || context()->IsStackValue());
          Label materialize_true, materialize_false, done;
          VisitForControl(expr->expression(), &materialize_false,
                          &materialize_true, &materialize_true);
          if (!context()->IsAccumulatorValue()) OperandStackDepthIncrement(1);
          __ bind(&materialize_true);
          __ LoadRoot(r2, Heap::kTrueValueRootIndex);
          if (context()->IsStackValue()) __ push(r2);
          __ b(&done);
          __ bind(&materialize_false);
          __ LoadRoot(r2, Heap::kFalseValueRootIndex);
          if (context()->IsStackValue()) __ push(r2);
          __ bind(&done);
        }
        break;
      }
  
      case Token::TYPEOF: {
        Comment cmnt(masm_, "[ UnaryOperation (TYPEOF)");
        {
          AccumulatorValueContext context(this);
          VisitForTypeofValue(expr->expression());
        }
        __ LoadRR(r5, r2);
        __ Call(isolate()->builtins()->Typeof(), RelocInfo::CODE_TARGET);
        context()->Plug(r2);
        break;
      }
  
      default:
        UNREACHABLE();
    }
  }
  
  void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
    DCHECK(expr->expression()->IsValidReferenceExpressionOrThis());
  
    Comment cmnt(masm_, "[ CountOperation");
  
    Property* prop = expr->expression()->AsProperty();
    LhsKind assign_type = Property::GetAssignType(prop);
  
    // Evaluate expression and get value.
    if (assign_type == VARIABLE) {
      DCHECK(expr->expression()->AsVariableProxy()->var() != NULL);
      AccumulatorValueContext context(this);
      EmitVariableLoad(expr->expression()->AsVariableProxy());
    } else {
      // Reserve space for result of postfix operation.
      if (expr->is_postfix() && !context()->IsEffect()) {
        __ LoadSmiLiteral(ip, Smi::kZero);
        PushOperand(ip);
      }
      switch (assign_type) {
        case NAMED_PROPERTY: {
          // Put the object both on the stack and in the register.
          VisitForStackValue(prop->obj());
          __ LoadP(LoadDescriptor::ReceiverRegister(), MemOperand(sp, 0));
          EmitNamedPropertyLoad(prop);
          break;
        }
  
        case KEYED_PROPERTY: {
          VisitForStackValue(prop->obj());
          VisitForStackValue(prop->key());
          __ LoadP(LoadDescriptor::ReceiverRegister(),
                   MemOperand(sp, 1 * kPointerSize));
          __ LoadP(LoadDescriptor::NameRegister(), MemOperand(sp, 0));
          EmitKeyedPropertyLoad(prop);
          break;
        }
  
        case NAMED_SUPER_PROPERTY:
        case KEYED_SUPER_PROPERTY:
        case VARIABLE:
          UNREACHABLE();
      }
    }
  
    // Convert old value into a number.
    __ Call(isolate()->builtins()->ToNumber(), RelocInfo::CODE_TARGET);
    RestoreContext();
  
    // 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:
            PushOperand(r2);
            break;
          case NAMED_PROPERTY:
            __ StoreP(r2, MemOperand(sp, kPointerSize));
            break;
          case KEYED_PROPERTY:
            __ StoreP(r2, MemOperand(sp, 2 * kPointerSize));
            break;
          case NAMED_SUPER_PROPERTY:
          case KEYED_SUPER_PROPERTY:
            UNREACHABLE();
            break;
        }
      }
    }
  
    int count_value = expr->op() == Token::INC ? 1 : -1;
    __ LoadRR(r3, r2);
    __ LoadSmiLiteral(r2, Smi::FromInt(count_value));
  
    SetExpressionPosition(expr);
  
    Handle<Code> code =
        CodeFactory::BinaryOperation(isolate(), Token::ADD).code();
    __ Call(code, RelocInfo::CODE_TARGET);
    RestoreContext();
  
    // Store the value returned in r2.
    switch (assign_type) {
      case VARIABLE: {
        VariableProxy* proxy = expr->expression()->AsVariableProxy();
        if (expr->is_postfix()) {
          {
            EffectContext context(this);
            EmitVariableAssignment(proxy->var(), Token::ASSIGN, expr->CountSlot(),
                                   proxy->hole_check_mode());
            context.Plug(r2);
          }
          // For all contexts except EffectConstant We have the result on
          // top of the stack.
          if (!context()->IsEffect()) {
            context()->PlugTOS();
          }
        } else {
          EmitVariableAssignment(proxy->var(), Token::ASSIGN, expr->CountSlot(),
                                 proxy->hole_check_mode());
          context()->Plug(r2);
        }
        break;
      }
      case NAMED_PROPERTY: {
        PopOperand(StoreDescriptor::ReceiverRegister());
        CallStoreIC(expr->CountSlot(), prop->key()->AsLiteral()->value());
        if (expr->is_postfix()) {
          if (!context()->IsEffect()) {
            context()->PlugTOS();
          }
        } else {
          context()->Plug(r2);
        }
        break;
      }
      case KEYED_PROPERTY: {
        PopOperands(StoreDescriptor::ReceiverRegister(),
                    StoreDescriptor::NameRegister());
        CallKeyedStoreIC(expr->CountSlot());
        if (expr->is_postfix()) {
          if (!context()->IsEffect()) {
            context()->PlugTOS();
          }
        } else {
          context()->Plug(r2);
        }
        break;
      }
      case NAMED_SUPER_PROPERTY:
      case KEYED_SUPER_PROPERTY:
        UNREACHABLE();
        break;
    }
  }
  
  void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
                                                   Expression* sub_expr,
                                                   Handle<String> check) {
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
                           &if_false, &fall_through);
  
    {
      AccumulatorValueContext context(this);
      VisitForTypeofValue(sub_expr);
    }
  
    Factory* factory = isolate()->factory();
    if (String::Equals(check, factory->number_string())) {
      __ JumpIfSmi(r2, if_true);
      __ LoadP(r2, FieldMemOperand(r2, HeapObject::kMapOffset));
      __ CompareRoot(r2, Heap::kHeapNumberMapRootIndex);
      Split(eq, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->string_string())) {
      __ JumpIfSmi(r2, if_false);
      __ CompareObjectType(r2, r2, r3, FIRST_NONSTRING_TYPE);
      Split(lt, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->symbol_string())) {
      __ JumpIfSmi(r2, if_false);
      __ CompareObjectType(r2, r2, r3, SYMBOL_TYPE);
      Split(eq, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->boolean_string())) {
      __ CompareRoot(r2, Heap::kTrueValueRootIndex);
      __ beq(if_true);
      __ CompareRoot(r2, Heap::kFalseValueRootIndex);
      Split(eq, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->undefined_string())) {
      __ CompareRoot(r2, Heap::kNullValueRootIndex);
      __ beq(if_false);
      __ JumpIfSmi(r2, if_false);
      // Check for undetectable objects => true.
      __ LoadP(r2, FieldMemOperand(r2, HeapObject::kMapOffset));
      __ tm(FieldMemOperand(r2, Map::kBitFieldOffset),
            Operand(1 << Map::kIsUndetectable));
      Split(ne, if_true, if_false, fall_through);
  
    } else if (String::Equals(check, factory->function_string())) {
      __ JumpIfSmi(r2, if_false);
      __ LoadP(r2, FieldMemOperand(r2, HeapObject::kMapOffset));
      __ LoadlB(r3, FieldMemOperand(r2, Map::kBitFieldOffset));
      __ AndP(r3, r3,
              Operand((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
      __ CmpP(r3, Operand(1 << Map::kIsCallable));
      Split(eq, if_true, if_false, fall_through);
    } else if (String::Equals(check, factory->object_string())) {
      __ JumpIfSmi(r2, if_false);
      __ CompareRoot(r2, Heap::kNullValueRootIndex);
      __ beq(if_true);
      STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
      __ CompareObjectType(r2, r2, r3, FIRST_JS_RECEIVER_TYPE);
      __ blt(if_false);
      __ tm(FieldMemOperand(r2, Map::kBitFieldOffset),
            Operand((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
      Split(eq, if_true, if_false, fall_through);
    } else {
      if (if_false != fall_through) __ b(if_false);
    }
    context()->Plug(if_true, if_false);
  }
  
  void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
    Comment cmnt(masm_, "[ CompareOperation");
  
    // First we try a fast inlined version of the compare when one of
    // the operands is a literal.
    if (TryLiteralCompare(expr)) return;
  
    // Always perform the comparison for its control flow.  Pack the result
    // into the expression's context after the comparison is performed.
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
                           &if_false, &fall_through);
  
    Token::Value op = expr->op();
    VisitForStackValue(expr->left());
    switch (op) {
      case Token::IN:
        VisitForStackValue(expr->right());
        SetExpressionPosition(expr);
        EmitHasProperty();
        __ CompareRoot(r2, Heap::kTrueValueRootIndex);
        Split(eq, if_true, if_false, fall_through);
        break;
  
      case Token::INSTANCEOF: {
        VisitForAccumulatorValue(expr->right());
        SetExpressionPosition(expr);
        PopOperand(r3);
        __ Call(isolate()->builtins()->InstanceOf(), RelocInfo::CODE_TARGET);
        RestoreContext();
        __ CompareRoot(r2, Heap::kTrueValueRootIndex);
        Split(eq, if_true, if_false, fall_through);
        break;
      }
  
      default: {
        VisitForAccumulatorValue(expr->right());
        SetExpressionPosition(expr);
        Condition cond = CompareIC::ComputeCondition(op);
        PopOperand(r3);
  
        bool inline_smi_code = ShouldInlineSmiCase(op);
        JumpPatchSite patch_site(masm_);
        if (inline_smi_code) {
          Label slow_case;
          __ LoadRR(r4, r3);
          __ OrP(r4, r2);
          patch_site.EmitJumpIfNotSmi(r4, &slow_case);
          __ CmpP(r3, r2);
          Split(cond, if_true, if_false, NULL);
          __ bind(&slow_case);
        }
  
        Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
        CallIC(ic);
        patch_site.EmitPatchInfo();
        __ CmpP(r2, Operand::Zero());
        Split(cond, if_true, if_false, fall_through);
      }
    }
  
    // Convert the result of the comparison into one expected for this
    // expression's context.
    context()->Plug(if_true, if_false);
  }
  
  void FullCodeGenerator::EmitLiteralCompareNil(CompareOperation* expr,
                                                Expression* sub_expr,
                                                NilValue nil) {
    Label materialize_true, materialize_false;
    Label* if_true = NULL;
    Label* if_false = NULL;
    Label* fall_through = NULL;
    context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
                           &if_false, &fall_through);
  
    VisitForAccumulatorValue(sub_expr);
    if (expr->op() == Token::EQ_STRICT) {
      Heap::RootListIndex nil_value = nil == kNullValue
                                          ? Heap::kNullValueRootIndex
                                          : Heap::kUndefinedValueRootIndex;
      __ CompareRoot(r2, nil_value);
      Split(eq, if_true, if_false, fall_through);
    } else {
      __ JumpIfSmi(r2, if_false);
      __ LoadP(r2, FieldMemOperand(r2, HeapObject::kMapOffset));
      __ LoadlB(r3, FieldMemOperand(r2, Map::kBitFieldOffset));
      __ AndP(r0, r3, Operand(1 << Map::kIsUndetectable));
      Split(ne, if_true, if_false, fall_through);
    }
    context()->Plug(if_true, if_false);
  }
  Register FullCodeGenerator::result_register() { return r2; }
  
  Register FullCodeGenerator::context_register() { return cp; }
  
  void FullCodeGenerator::LoadFromFrameField(int frame_offset, Register value) {
    DCHECK_EQ(static_cast<int>(POINTER_SIZE_ALIGN(frame_offset)), frame_offset);
    __ LoadP(value, MemOperand(fp, frame_offset));
  }
  
  void FullCodeGenerator::StoreToFrameField(int frame_offset, Register value) {
    DCHECK_EQ(static_cast<int>(POINTER_SIZE_ALIGN(frame_offset)), frame_offset);
    __ StoreP(value, MemOperand(fp, frame_offset));
  }
  
  void FullCodeGenerator::LoadContextField(Register dst, int context_index) {
    __ LoadP(dst, ContextMemOperand(cp, context_index), r0);
  }
  
  void FullCodeGenerator::PushFunctionArgumentForContextAllocation() {
    DeclarationScope* closure_scope = scope()->GetClosureScope();
    if (closure_scope->is_script_scope() || closure_scope->is_module_scope()) {
      // Contexts nested in the native context have a canonical empty function
      // as their closure, not the anonymous closure containing the global
      // code.
      __ LoadNativeContextSlot(Context::CLOSURE_INDEX, ip);
    } else if (closure_scope->is_eval_scope()) {
      // Contexts created by a call to eval have the same closure as the
      // context calling eval, not the anonymous closure containing the eval
      // code.  Fetch it from the context.
      __ LoadP(ip, ContextMemOperand(cp, Context::CLOSURE_INDEX));
    } else {
      DCHECK(closure_scope->is_function_scope());
      __ LoadP(ip, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
    }
    PushOperand(ip);
  }
  
  #undef __
  
  #if V8_TARGET_ARCH_S390X
  static const FourByteInstr kInterruptBranchInstruction = 0xA7A40011;
  static const FourByteInstr kOSRBranchInstruction = 0xA7040011;
  static const int16_t kBackEdgeBranchOffsetInHalfWords = 0x11;
  #else
  static const FourByteInstr kInterruptBranchInstruction = 0xA7A4000D;
  static const FourByteInstr kOSRBranchInstruction = 0xA704000D;
  static const int16_t kBackEdgeBranchOffsetInHalfWords = 0xD;
  #endif
  
  void BackEdgeTable::PatchAt(Code* unoptimized_code, Address pc,
                              BackEdgeState target_state,
                              Code* replacement_code) {
    Address call_address = Assembler::target_address_from_return_address(pc);
    Address branch_address = call_address - 4;
    Isolate* isolate = unoptimized_code->GetIsolate();
    CodePatcher patcher(isolate, branch_address, 4);
  
    switch (target_state) {
      case INTERRUPT: {
        //  <decrement profiling counter>
        //         bge     <ok>            ;; patched to GE BRC
        //         brasrl    r14, <interrupt stub address>
        //  <reset profiling counter>
        //  ok-label
        patcher.masm()->brc(ge, Operand(kBackEdgeBranchOffsetInHalfWords));
        break;
      }
      case ON_STACK_REPLACEMENT:
        //  <decrement profiling counter>
        //         brc   0x0, <ok>            ;;  patched to NOP BRC
        //         brasrl    r14, <interrupt stub address>
        //  <reset profiling counter>
        //  ok-label ----- pc_after points here
        patcher.masm()->brc(CC_NOP, Operand(kBackEdgeBranchOffsetInHalfWords));
        break;
    }
  
    // Replace the stack check address in the mov sequence with the
    // entry address of the replacement code.
    Assembler::set_target_address_at(isolate, call_address, unoptimized_code,
                                     replacement_code->entry());
  
    unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
        unoptimized_code, call_address, replacement_code);
  }
  
  BackEdgeTable::BackEdgeState BackEdgeTable::GetBackEdgeState(
      Isolate* isolate, Code* unoptimized_code, Address pc) {
    Address call_address = Assembler::target_address_from_return_address(pc);
    Address branch_address = call_address - 4;
  #ifdef DEBUG
    Address interrupt_address =
        Assembler::target_address_at(call_address, unoptimized_code);
  #endif
  
    DCHECK(BRC == Instruction::S390OpcodeValue(branch_address));
    // For interrupt, we expect a branch greater than or equal
    // i.e. BRC 0xa, +XXXX  (0xA7A4XXXX)
    FourByteInstr br_instr = Instruction::InstructionBits(
        reinterpret_cast<const byte*>(branch_address));
    if (kInterruptBranchInstruction == br_instr) {
      DCHECK(interrupt_address == isolate->builtins()->InterruptCheck()->entry());
      return INTERRUPT;
    }
  
    // Expect BRC to be patched to NOP branch.
    // i.e. BRC 0x0, +XXXX (0xA704XXXX)
    USE(kOSRBranchInstruction);
    DCHECK(kOSRBranchInstruction == br_instr);
  
    DCHECK(interrupt_address ==
           isolate->builtins()->OnStackReplacement()->entry());
    return ON_STACK_REPLACEMENT;
  }
  }  // namespace internal
  }  // namespace v8
  #endif  // V8_TARGET_ARCH_S390
  