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      1 // Copyright 2013 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "src/v8.h"
      6 
      7 #if V8_TARGET_ARCH_ARM64
      8 
      9 #include "src/code-factory.h"
     10 #include "src/code-stubs.h"
     11 #include "src/codegen.h"
     12 #include "src/compiler.h"
     13 #include "src/debug.h"
     14 #include "src/full-codegen.h"
     15 #include "src/ic/ic.h"
     16 #include "src/isolate-inl.h"
     17 #include "src/parser.h"
     18 #include "src/scopes.h"
     19 
     20 #include "src/arm64/code-stubs-arm64.h"
     21 #include "src/arm64/macro-assembler-arm64.h"
     22 
     23 namespace v8 {
     24 namespace internal {
     25 
     26 #define __ ACCESS_MASM(masm_)
     27 
     28 class JumpPatchSite BASE_EMBEDDED {
     29  public:
     30   explicit JumpPatchSite(MacroAssembler* masm) : masm_(masm), reg_(NoReg) {
     31 #ifdef DEBUG
     32     info_emitted_ = false;
     33 #endif
     34   }
     35 
     36   ~JumpPatchSite() {
     37     if (patch_site_.is_bound()) {
     38       DCHECK(info_emitted_);
     39     } else {
     40       DCHECK(reg_.IsNone());
     41     }
     42   }
     43 
     44   void EmitJumpIfNotSmi(Register reg, Label* target) {
     45     // This code will be patched by PatchInlinedSmiCode, in ic-arm64.cc.
     46     InstructionAccurateScope scope(masm_, 1);
     47     DCHECK(!info_emitted_);
     48     DCHECK(reg.Is64Bits());
     49     DCHECK(!reg.Is(csp));
     50     reg_ = reg;
     51     __ bind(&patch_site_);
     52     __ tbz(xzr, 0, target);   // Always taken before patched.
     53   }
     54 
     55   void EmitJumpIfSmi(Register reg, Label* target) {
     56     // This code will be patched by PatchInlinedSmiCode, in ic-arm64.cc.
     57     InstructionAccurateScope scope(masm_, 1);
     58     DCHECK(!info_emitted_);
     59     DCHECK(reg.Is64Bits());
     60     DCHECK(!reg.Is(csp));
     61     reg_ = reg;
     62     __ bind(&patch_site_);
     63     __ tbnz(xzr, 0, target);  // Never taken before patched.
     64   }
     65 
     66   void EmitJumpIfEitherNotSmi(Register reg1, Register reg2, Label* target) {
     67     UseScratchRegisterScope temps(masm_);
     68     Register temp = temps.AcquireX();
     69     __ Orr(temp, reg1, reg2);
     70     EmitJumpIfNotSmi(temp, target);
     71   }
     72 
     73   void EmitPatchInfo() {
     74     Assembler::BlockPoolsScope scope(masm_);
     75     InlineSmiCheckInfo::Emit(masm_, reg_, &patch_site_);
     76 #ifdef DEBUG
     77     info_emitted_ = true;
     78 #endif
     79   }
     80 
     81  private:
     82   MacroAssembler* masm_;
     83   Label patch_site_;
     84   Register reg_;
     85 #ifdef DEBUG
     86   bool info_emitted_;
     87 #endif
     88 };
     89 
     90 
     91 // Generate code for a JS function. On entry to the function the receiver
     92 // and arguments have been pushed on the stack left to right. The actual
     93 // argument count matches the formal parameter count expected by the
     94 // function.
     95 //
     96 // The live registers are:
     97 //   - x1: the JS function object being called (i.e. ourselves).
     98 //   - cp: our context.
     99 //   - fp: our caller's frame pointer.
    100 //   - jssp: stack pointer.
    101 //   - lr: return address.
    102 //
    103 // The function builds a JS frame. See JavaScriptFrameConstants in
    104 // frames-arm.h for its layout.
    105 void FullCodeGenerator::Generate() {
    106   CompilationInfo* info = info_;
    107   handler_table_ =
    108       isolate()->factory()->NewFixedArray(function()->handler_count(), TENURED);
    109 
    110   profiling_counter_ = isolate()->factory()->NewCell(
    111       Handle<Smi>(Smi::FromInt(FLAG_interrupt_budget), isolate()));
    112   SetFunctionPosition(function());
    113   Comment cmnt(masm_, "[ Function compiled by full code generator");
    114 
    115   ProfileEntryHookStub::MaybeCallEntryHook(masm_);
    116 
    117 #ifdef DEBUG
    118   if (strlen(FLAG_stop_at) > 0 &&
    119       info->function()->name()->IsUtf8EqualTo(CStrVector(FLAG_stop_at))) {
    120     __ Debug("stop-at", __LINE__, BREAK);
    121   }
    122 #endif
    123 
    124   // Sloppy mode functions and builtins need to replace the receiver with the
    125   // global proxy when called as functions (without an explicit receiver
    126   // object).
    127   if (info->strict_mode() == SLOPPY && !info->is_native()) {
    128     Label ok;
    129     int receiver_offset = info->scope()->num_parameters() * kXRegSize;
    130     __ Peek(x10, receiver_offset);
    131     __ JumpIfNotRoot(x10, Heap::kUndefinedValueRootIndex, &ok);
    132 
    133     __ Ldr(x10, GlobalObjectMemOperand());
    134     __ Ldr(x10, FieldMemOperand(x10, GlobalObject::kGlobalProxyOffset));
    135     __ Poke(x10, receiver_offset);
    136 
    137     __ Bind(&ok);
    138   }
    139 
    140 
    141   // Open a frame scope to indicate that there is a frame on the stack.
    142   // The MANUAL indicates that the scope shouldn't actually generate code
    143   // to set up the frame because we do it manually below.
    144   FrameScope frame_scope(masm_, StackFrame::MANUAL);
    145 
    146   // This call emits the following sequence in a way that can be patched for
    147   // code ageing support:
    148   //  Push(lr, fp, cp, x1);
    149   //  Add(fp, jssp, 2 * kPointerSize);
    150   info->set_prologue_offset(masm_->pc_offset());
    151   __ Prologue(info->IsCodePreAgingActive());
    152   info->AddNoFrameRange(0, masm_->pc_offset());
    153 
    154   // Reserve space on the stack for locals.
    155   { Comment cmnt(masm_, "[ Allocate locals");
    156     int locals_count = info->scope()->num_stack_slots();
    157     // Generators allocate locals, if any, in context slots.
    158     DCHECK(!info->function()->is_generator() || locals_count == 0);
    159 
    160     if (locals_count > 0) {
    161       if (locals_count >= 128) {
    162         Label ok;
    163         DCHECK(jssp.Is(__ StackPointer()));
    164         __ Sub(x10, jssp, locals_count * kPointerSize);
    165         __ CompareRoot(x10, Heap::kRealStackLimitRootIndex);
    166         __ B(hs, &ok);
    167         __ InvokeBuiltin(Builtins::STACK_OVERFLOW, CALL_FUNCTION);
    168         __ Bind(&ok);
    169       }
    170       __ LoadRoot(x10, Heap::kUndefinedValueRootIndex);
    171       if (FLAG_optimize_for_size) {
    172         __ PushMultipleTimes(x10 , locals_count);
    173       } else {
    174         const int kMaxPushes = 32;
    175         if (locals_count >= kMaxPushes) {
    176           int loop_iterations = locals_count / kMaxPushes;
    177           __ Mov(x3, loop_iterations);
    178           Label loop_header;
    179           __ Bind(&loop_header);
    180           // Do pushes.
    181           __ PushMultipleTimes(x10 , kMaxPushes);
    182           __ Subs(x3, x3, 1);
    183           __ B(ne, &loop_header);
    184         }
    185         int remaining = locals_count % kMaxPushes;
    186         // Emit the remaining pushes.
    187         __ PushMultipleTimes(x10 , remaining);
    188       }
    189     }
    190   }
    191 
    192   bool function_in_register_x1 = true;
    193 
    194   int heap_slots = info->scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
    195   if (heap_slots > 0) {
    196     // Argument to NewContext is the function, which is still in x1.
    197     Comment cmnt(masm_, "[ Allocate context");
    198     bool need_write_barrier = true;
    199     if (FLAG_harmony_scoping && info->scope()->is_global_scope()) {
    200       __ Mov(x10, Operand(info->scope()->GetScopeInfo()));
    201       __ Push(x1, x10);
    202       __ CallRuntime(Runtime::kNewGlobalContext, 2);
    203     } else if (heap_slots <= FastNewContextStub::kMaximumSlots) {
    204       FastNewContextStub stub(isolate(), heap_slots);
    205       __ CallStub(&stub);
    206       // Result of FastNewContextStub is always in new space.
    207       need_write_barrier = false;
    208     } else {
    209       __ Push(x1);
    210       __ CallRuntime(Runtime::kNewFunctionContext, 1);
    211     }
    212     function_in_register_x1 = false;
    213     // Context is returned in x0.  It replaces the context passed to us.
    214     // It's saved in the stack and kept live in cp.
    215     __ Mov(cp, x0);
    216     __ Str(x0, MemOperand(fp, StandardFrameConstants::kContextOffset));
    217     // Copy any necessary parameters into the context.
    218     int num_parameters = info->scope()->num_parameters();
    219     for (int i = 0; i < num_parameters; i++) {
    220       Variable* var = scope()->parameter(i);
    221       if (var->IsContextSlot()) {
    222         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
    223             (num_parameters - 1 - i) * kPointerSize;
    224         // Load parameter from stack.
    225         __ Ldr(x10, MemOperand(fp, parameter_offset));
    226         // Store it in the context.
    227         MemOperand target = ContextMemOperand(cp, var->index());
    228         __ Str(x10, target);
    229 
    230         // Update the write barrier.
    231         if (need_write_barrier) {
    232           __ RecordWriteContextSlot(
    233               cp, target.offset(), x10, x11, kLRHasBeenSaved, kDontSaveFPRegs);
    234         } else if (FLAG_debug_code) {
    235           Label done;
    236           __ JumpIfInNewSpace(cp, &done);
    237           __ Abort(kExpectedNewSpaceObject);
    238           __ bind(&done);
    239         }
    240       }
    241     }
    242   }
    243 
    244   Variable* arguments = scope()->arguments();
    245   if (arguments != NULL) {
    246     // Function uses arguments object.
    247     Comment cmnt(masm_, "[ Allocate arguments object");
    248     if (!function_in_register_x1) {
    249       // Load this again, if it's used by the local context below.
    250       __ Ldr(x3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
    251     } else {
    252       __ Mov(x3, x1);
    253     }
    254     // Receiver is just before the parameters on the caller's stack.
    255     int num_parameters = info->scope()->num_parameters();
    256     int offset = num_parameters * kPointerSize;
    257     __ Add(x2, fp, StandardFrameConstants::kCallerSPOffset + offset);
    258     __ Mov(x1, Smi::FromInt(num_parameters));
    259     __ Push(x3, x2, x1);
    260 
    261     // Arguments to ArgumentsAccessStub:
    262     //   function, receiver address, parameter count.
    263     // The stub will rewrite receiver and parameter count if the previous
    264     // stack frame was an arguments adapter frame.
    265     ArgumentsAccessStub::Type type;
    266     if (strict_mode() == STRICT) {
    267       type = ArgumentsAccessStub::NEW_STRICT;
    268     } else if (function()->has_duplicate_parameters()) {
    269       type = ArgumentsAccessStub::NEW_SLOPPY_SLOW;
    270     } else {
    271       type = ArgumentsAccessStub::NEW_SLOPPY_FAST;
    272     }
    273     ArgumentsAccessStub stub(isolate(), type);
    274     __ CallStub(&stub);
    275 
    276     SetVar(arguments, x0, x1, x2);
    277   }
    278 
    279   if (FLAG_trace) {
    280     __ CallRuntime(Runtime::kTraceEnter, 0);
    281   }
    282 
    283 
    284   // Visit the declarations and body unless there is an illegal
    285   // redeclaration.
    286   if (scope()->HasIllegalRedeclaration()) {
    287     Comment cmnt(masm_, "[ Declarations");
    288     scope()->VisitIllegalRedeclaration(this);
    289 
    290   } else {
    291     PrepareForBailoutForId(BailoutId::FunctionEntry(), NO_REGISTERS);
    292     { Comment cmnt(masm_, "[ Declarations");
    293       if (scope()->is_function_scope() && scope()->function() != NULL) {
    294         VariableDeclaration* function = scope()->function();
    295         DCHECK(function->proxy()->var()->mode() == CONST ||
    296                function->proxy()->var()->mode() == CONST_LEGACY);
    297         DCHECK(function->proxy()->var()->location() != Variable::UNALLOCATED);
    298         VisitVariableDeclaration(function);
    299       }
    300       VisitDeclarations(scope()->declarations());
    301     }
    302   }
    303 
    304   { Comment cmnt(masm_, "[ Stack check");
    305     PrepareForBailoutForId(BailoutId::Declarations(), NO_REGISTERS);
    306     Label ok;
    307     DCHECK(jssp.Is(__ StackPointer()));
    308     __ CompareRoot(jssp, Heap::kStackLimitRootIndex);
    309     __ B(hs, &ok);
    310     PredictableCodeSizeScope predictable(masm_,
    311                                          Assembler::kCallSizeWithRelocation);
    312     __ Call(isolate()->builtins()->StackCheck(), RelocInfo::CODE_TARGET);
    313     __ Bind(&ok);
    314   }
    315 
    316   { Comment cmnt(masm_, "[ Body");
    317     DCHECK(loop_depth() == 0);
    318     VisitStatements(function()->body());
    319     DCHECK(loop_depth() == 0);
    320   }
    321 
    322   // Always emit a 'return undefined' in case control fell off the end of
    323   // the body.
    324   { Comment cmnt(masm_, "[ return <undefined>;");
    325     __ LoadRoot(x0, Heap::kUndefinedValueRootIndex);
    326   }
    327   EmitReturnSequence();
    328 
    329   // Force emission of the pools, so they don't get emitted in the middle
    330   // of the back edge table.
    331   masm()->CheckVeneerPool(true, false);
    332   masm()->CheckConstPool(true, false);
    333 }
    334 
    335 
    336 void FullCodeGenerator::ClearAccumulator() {
    337   __ Mov(x0, Smi::FromInt(0));
    338 }
    339 
    340 
    341 void FullCodeGenerator::EmitProfilingCounterDecrement(int delta) {
    342   __ Mov(x2, Operand(profiling_counter_));
    343   __ Ldr(x3, FieldMemOperand(x2, Cell::kValueOffset));
    344   __ Subs(x3, x3, Smi::FromInt(delta));
    345   __ Str(x3, FieldMemOperand(x2, Cell::kValueOffset));
    346 }
    347 
    348 
    349 void FullCodeGenerator::EmitProfilingCounterReset() {
    350   int reset_value = FLAG_interrupt_budget;
    351   if (info_->is_debug()) {
    352     // Detect debug break requests as soon as possible.
    353     reset_value = FLAG_interrupt_budget >> 4;
    354   }
    355   __ Mov(x2, Operand(profiling_counter_));
    356   __ Mov(x3, Smi::FromInt(reset_value));
    357   __ Str(x3, FieldMemOperand(x2, Cell::kValueOffset));
    358 }
    359 
    360 
    361 void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
    362                                                 Label* back_edge_target) {
    363   DCHECK(jssp.Is(__ StackPointer()));
    364   Comment cmnt(masm_, "[ Back edge bookkeeping");
    365   // Block literal pools whilst emitting back edge code.
    366   Assembler::BlockPoolsScope block_const_pool(masm_);
    367   Label ok;
    368 
    369   DCHECK(back_edge_target->is_bound());
    370   // We want to do a round rather than a floor of distance/kCodeSizeMultiplier
    371   // to reduce the absolute error due to the integer division. To do that,
    372   // we add kCodeSizeMultiplier/2 to the distance (equivalent to adding 0.5 to
    373   // the result).
    374   int distance =
    375     masm_->SizeOfCodeGeneratedSince(back_edge_target) + kCodeSizeMultiplier / 2;
    376   int weight = Min(kMaxBackEdgeWeight,
    377                    Max(1, distance / kCodeSizeMultiplier));
    378   EmitProfilingCounterDecrement(weight);
    379   __ B(pl, &ok);
    380   __ Call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
    381 
    382   // Record a mapping of this PC offset to the OSR id.  This is used to find
    383   // the AST id from the unoptimized code in order to use it as a key into
    384   // the deoptimization input data found in the optimized code.
    385   RecordBackEdge(stmt->OsrEntryId());
    386 
    387   EmitProfilingCounterReset();
    388 
    389   __ Bind(&ok);
    390   PrepareForBailoutForId(stmt->EntryId(), NO_REGISTERS);
    391   // Record a mapping of the OSR id to this PC.  This is used if the OSR
    392   // entry becomes the target of a bailout.  We don't expect it to be, but
    393   // we want it to work if it is.
    394   PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
    395 }
    396 
    397 
    398 void FullCodeGenerator::EmitReturnSequence() {
    399   Comment cmnt(masm_, "[ Return sequence");
    400 
    401   if (return_label_.is_bound()) {
    402     __ B(&return_label_);
    403 
    404   } else {
    405     __ Bind(&return_label_);
    406     if (FLAG_trace) {
    407       // Push the return value on the stack as the parameter.
    408       // Runtime::TraceExit returns its parameter in x0.
    409       __ Push(result_register());
    410       __ CallRuntime(Runtime::kTraceExit, 1);
    411       DCHECK(x0.Is(result_register()));
    412     }
    413     // Pretend that the exit is a backwards jump to the entry.
    414     int weight = 1;
    415     if (info_->ShouldSelfOptimize()) {
    416       weight = FLAG_interrupt_budget / FLAG_self_opt_count;
    417     } else {
    418       int distance = masm_->pc_offset() + kCodeSizeMultiplier / 2;
    419       weight = Min(kMaxBackEdgeWeight,
    420                    Max(1, distance / kCodeSizeMultiplier));
    421     }
    422     EmitProfilingCounterDecrement(weight);
    423     Label ok;
    424     __ B(pl, &ok);
    425     __ Push(x0);
    426     __ Call(isolate()->builtins()->InterruptCheck(),
    427             RelocInfo::CODE_TARGET);
    428     __ Pop(x0);
    429     EmitProfilingCounterReset();
    430     __ Bind(&ok);
    431 
    432     // Make sure that the constant pool is not emitted inside of the return
    433     // sequence. This sequence can get patched when the debugger is used. See
    434     // debug-arm64.cc:BreakLocationIterator::SetDebugBreakAtReturn().
    435     {
    436       InstructionAccurateScope scope(masm_,
    437                                      Assembler::kJSRetSequenceInstructions);
    438       CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
    439       __ RecordJSReturn();
    440       // This code is generated using Assembler methods rather than Macro
    441       // Assembler methods because it will be patched later on, and so the size
    442       // of the generated code must be consistent.
    443       const Register& current_sp = __ StackPointer();
    444       // Nothing ensures 16 bytes alignment here.
    445       DCHECK(!current_sp.Is(csp));
    446       __ mov(current_sp, fp);
    447       int no_frame_start = masm_->pc_offset();
    448       __ ldp(fp, lr, MemOperand(current_sp, 2 * kXRegSize, PostIndex));
    449       // Drop the arguments and receiver and return.
    450       // TODO(all): This implementation is overkill as it supports 2**31+1
    451       // arguments, consider how to improve it without creating a security
    452       // hole.
    453       __ ldr_pcrel(ip0, (3 * kInstructionSize) >> kLoadLiteralScaleLog2);
    454       __ add(current_sp, current_sp, ip0);
    455       __ ret();
    456       __ dc64(kXRegSize * (info_->scope()->num_parameters() + 1));
    457       info_->AddNoFrameRange(no_frame_start, masm_->pc_offset());
    458     }
    459   }
    460 }
    461 
    462 
    463 void FullCodeGenerator::EffectContext::Plug(Variable* var) const {
    464   DCHECK(var->IsStackAllocated() || var->IsContextSlot());
    465 }
    466 
    467 
    468 void FullCodeGenerator::AccumulatorValueContext::Plug(Variable* var) const {
    469   DCHECK(var->IsStackAllocated() || var->IsContextSlot());
    470   codegen()->GetVar(result_register(), var);
    471 }
    472 
    473 
    474 void FullCodeGenerator::StackValueContext::Plug(Variable* var) const {
    475   DCHECK(var->IsStackAllocated() || var->IsContextSlot());
    476   codegen()->GetVar(result_register(), var);
    477   __ Push(result_register());
    478 }
    479 
    480 
    481 void FullCodeGenerator::TestContext::Plug(Variable* var) const {
    482   DCHECK(var->IsStackAllocated() || var->IsContextSlot());
    483   // For simplicity we always test the accumulator register.
    484   codegen()->GetVar(result_register(), var);
    485   codegen()->PrepareForBailoutBeforeSplit(condition(), false, NULL, NULL);
    486   codegen()->DoTest(this);
    487 }
    488 
    489 
    490 void FullCodeGenerator::EffectContext::Plug(Heap::RootListIndex index) const {
    491   // Root values have no side effects.
    492 }
    493 
    494 
    495 void FullCodeGenerator::AccumulatorValueContext::Plug(
    496     Heap::RootListIndex index) const {
    497   __ LoadRoot(result_register(), index);
    498 }
    499 
    500 
    501 void FullCodeGenerator::StackValueContext::Plug(
    502     Heap::RootListIndex index) const {
    503   __ LoadRoot(result_register(), index);
    504   __ Push(result_register());
    505 }
    506 
    507 
    508 void FullCodeGenerator::TestContext::Plug(Heap::RootListIndex index) const {
    509   codegen()->PrepareForBailoutBeforeSplit(condition(), true, true_label_,
    510                                           false_label_);
    511   if (index == Heap::kUndefinedValueRootIndex ||
    512       index == Heap::kNullValueRootIndex ||
    513       index == Heap::kFalseValueRootIndex) {
    514     if (false_label_ != fall_through_) __ B(false_label_);
    515   } else if (index == Heap::kTrueValueRootIndex) {
    516     if (true_label_ != fall_through_) __ B(true_label_);
    517   } else {
    518     __ LoadRoot(result_register(), index);
    519     codegen()->DoTest(this);
    520   }
    521 }
    522 
    523 
    524 void FullCodeGenerator::EffectContext::Plug(Handle<Object> lit) const {
    525 }
    526 
    527 
    528 void FullCodeGenerator::AccumulatorValueContext::Plug(
    529     Handle<Object> lit) const {
    530   __ Mov(result_register(), Operand(lit));
    531 }
    532 
    533 
    534 void FullCodeGenerator::StackValueContext::Plug(Handle<Object> lit) const {
    535   // Immediates cannot be pushed directly.
    536   __ Mov(result_register(), Operand(lit));
    537   __ Push(result_register());
    538 }
    539 
    540 
    541 void FullCodeGenerator::TestContext::Plug(Handle<Object> lit) const {
    542   codegen()->PrepareForBailoutBeforeSplit(condition(),
    543                                           true,
    544                                           true_label_,
    545                                           false_label_);
    546   DCHECK(!lit->IsUndetectableObject());  // There are no undetectable literals.
    547   if (lit->IsUndefined() || lit->IsNull() || lit->IsFalse()) {
    548     if (false_label_ != fall_through_) __ B(false_label_);
    549   } else if (lit->IsTrue() || lit->IsJSObject()) {
    550     if (true_label_ != fall_through_) __ B(true_label_);
    551   } else if (lit->IsString()) {
    552     if (String::cast(*lit)->length() == 0) {
    553       if (false_label_ != fall_through_) __ B(false_label_);
    554     } else {
    555       if (true_label_ != fall_through_) __ B(true_label_);
    556     }
    557   } else if (lit->IsSmi()) {
    558     if (Smi::cast(*lit)->value() == 0) {
    559       if (false_label_ != fall_through_) __ B(false_label_);
    560     } else {
    561       if (true_label_ != fall_through_) __ B(true_label_);
    562     }
    563   } else {
    564     // For simplicity we always test the accumulator register.
    565     __ Mov(result_register(), Operand(lit));
    566     codegen()->DoTest(this);
    567   }
    568 }
    569 
    570 
    571 void FullCodeGenerator::EffectContext::DropAndPlug(int count,
    572                                                    Register reg) const {
    573   DCHECK(count > 0);
    574   __ Drop(count);
    575 }
    576 
    577 
    578 void FullCodeGenerator::AccumulatorValueContext::DropAndPlug(
    579     int count,
    580     Register reg) const {
    581   DCHECK(count > 0);
    582   __ Drop(count);
    583   __ Move(result_register(), reg);
    584 }
    585 
    586 
    587 void FullCodeGenerator::StackValueContext::DropAndPlug(int count,
    588                                                        Register reg) const {
    589   DCHECK(count > 0);
    590   if (count > 1) __ Drop(count - 1);
    591   __ Poke(reg, 0);
    592 }
    593 
    594 
    595 void FullCodeGenerator::TestContext::DropAndPlug(int count,
    596                                                  Register reg) const {
    597   DCHECK(count > 0);
    598   // For simplicity we always test the accumulator register.
    599   __ Drop(count);
    600   __ Mov(result_register(), reg);
    601   codegen()->PrepareForBailoutBeforeSplit(condition(), false, NULL, NULL);
    602   codegen()->DoTest(this);
    603 }
    604 
    605 
    606 void FullCodeGenerator::EffectContext::Plug(Label* materialize_true,
    607                                             Label* materialize_false) const {
    608   DCHECK(materialize_true == materialize_false);
    609   __ Bind(materialize_true);
    610 }
    611 
    612 
    613 void FullCodeGenerator::AccumulatorValueContext::Plug(
    614     Label* materialize_true,
    615     Label* materialize_false) const {
    616   Label done;
    617   __ Bind(materialize_true);
    618   __ LoadRoot(result_register(), Heap::kTrueValueRootIndex);
    619   __ B(&done);
    620   __ Bind(materialize_false);
    621   __ LoadRoot(result_register(), Heap::kFalseValueRootIndex);
    622   __ Bind(&done);
    623 }
    624 
    625 
    626 void FullCodeGenerator::StackValueContext::Plug(
    627     Label* materialize_true,
    628     Label* materialize_false) const {
    629   Label done;
    630   __ Bind(materialize_true);
    631   __ LoadRoot(x10, Heap::kTrueValueRootIndex);
    632   __ B(&done);
    633   __ Bind(materialize_false);
    634   __ LoadRoot(x10, Heap::kFalseValueRootIndex);
    635   __ Bind(&done);
    636   __ Push(x10);
    637 }
    638 
    639 
    640 void FullCodeGenerator::TestContext::Plug(Label* materialize_true,
    641                                           Label* materialize_false) const {
    642   DCHECK(materialize_true == true_label_);
    643   DCHECK(materialize_false == false_label_);
    644 }
    645 
    646 
    647 void FullCodeGenerator::EffectContext::Plug(bool flag) const {
    648 }
    649 
    650 
    651 void FullCodeGenerator::AccumulatorValueContext::Plug(bool flag) const {
    652   Heap::RootListIndex value_root_index =
    653       flag ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex;
    654   __ LoadRoot(result_register(), value_root_index);
    655 }
    656 
    657 
    658 void FullCodeGenerator::StackValueContext::Plug(bool flag) const {
    659   Heap::RootListIndex value_root_index =
    660       flag ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex;
    661   __ LoadRoot(x10, value_root_index);
    662   __ Push(x10);
    663 }
    664 
    665 
    666 void FullCodeGenerator::TestContext::Plug(bool flag) const {
    667   codegen()->PrepareForBailoutBeforeSplit(condition(),
    668                                           true,
    669                                           true_label_,
    670                                           false_label_);
    671   if (flag) {
    672     if (true_label_ != fall_through_) {
    673       __ B(true_label_);
    674     }
    675   } else {
    676     if (false_label_ != fall_through_) {
    677       __ B(false_label_);
    678     }
    679   }
    680 }
    681 
    682 
    683 void FullCodeGenerator::DoTest(Expression* condition,
    684                                Label* if_true,
    685                                Label* if_false,
    686                                Label* fall_through) {
    687   Handle<Code> ic = ToBooleanStub::GetUninitialized(isolate());
    688   CallIC(ic, condition->test_id());
    689   __ CompareAndSplit(result_register(), 0, ne, if_true, if_false, fall_through);
    690 }
    691 
    692 
    693 // If (cond), branch to if_true.
    694 // If (!cond), branch to if_false.
    695 // fall_through is used as an optimization in cases where only one branch
    696 // instruction is necessary.
    697 void FullCodeGenerator::Split(Condition cond,
    698                               Label* if_true,
    699                               Label* if_false,
    700                               Label* fall_through) {
    701   if (if_false == fall_through) {
    702     __ B(cond, if_true);
    703   } else if (if_true == fall_through) {
    704     DCHECK(if_false != fall_through);
    705     __ B(NegateCondition(cond), if_false);
    706   } else {
    707     __ B(cond, if_true);
    708     __ B(if_false);
    709   }
    710 }
    711 
    712 
    713 MemOperand FullCodeGenerator::StackOperand(Variable* var) {
    714   // Offset is negative because higher indexes are at lower addresses.
    715   int offset = -var->index() * kXRegSize;
    716   // Adjust by a (parameter or local) base offset.
    717   if (var->IsParameter()) {
    718     offset += (info_->scope()->num_parameters() + 1) * kPointerSize;
    719   } else {
    720     offset += JavaScriptFrameConstants::kLocal0Offset;
    721   }
    722   return MemOperand(fp, offset);
    723 }
    724 
    725 
    726 MemOperand FullCodeGenerator::VarOperand(Variable* var, Register scratch) {
    727   DCHECK(var->IsContextSlot() || var->IsStackAllocated());
    728   if (var->IsContextSlot()) {
    729     int context_chain_length = scope()->ContextChainLength(var->scope());
    730     __ LoadContext(scratch, context_chain_length);
    731     return ContextMemOperand(scratch, var->index());
    732   } else {
    733     return StackOperand(var);
    734   }
    735 }
    736 
    737 
    738 void FullCodeGenerator::GetVar(Register dest, Variable* var) {
    739   // Use destination as scratch.
    740   MemOperand location = VarOperand(var, dest);
    741   __ Ldr(dest, location);
    742 }
    743 
    744 
    745 void FullCodeGenerator::SetVar(Variable* var,
    746                                Register src,
    747                                Register scratch0,
    748                                Register scratch1) {
    749   DCHECK(var->IsContextSlot() || var->IsStackAllocated());
    750   DCHECK(!AreAliased(src, scratch0, scratch1));
    751   MemOperand location = VarOperand(var, scratch0);
    752   __ Str(src, location);
    753 
    754   // Emit the write barrier code if the location is in the heap.
    755   if (var->IsContextSlot()) {
    756     // scratch0 contains the correct context.
    757     __ RecordWriteContextSlot(scratch0,
    758                               location.offset(),
    759                               src,
    760                               scratch1,
    761                               kLRHasBeenSaved,
    762                               kDontSaveFPRegs);
    763   }
    764 }
    765 
    766 
    767 void FullCodeGenerator::PrepareForBailoutBeforeSplit(Expression* expr,
    768                                                      bool should_normalize,
    769                                                      Label* if_true,
    770                                                      Label* if_false) {
    771   // Only prepare for bailouts before splits if we're in a test
    772   // context. Otherwise, we let the Visit function deal with the
    773   // preparation to avoid preparing with the same AST id twice.
    774   if (!context()->IsTest() || !info_->IsOptimizable()) return;
    775 
    776   // TODO(all): Investigate to see if there is something to work on here.
    777   Label skip;
    778   if (should_normalize) {
    779     __ B(&skip);
    780   }
    781   PrepareForBailout(expr, TOS_REG);
    782   if (should_normalize) {
    783     __ CompareRoot(x0, Heap::kTrueValueRootIndex);
    784     Split(eq, if_true, if_false, NULL);
    785     __ Bind(&skip);
    786   }
    787 }
    788 
    789 
    790 void FullCodeGenerator::EmitDebugCheckDeclarationContext(Variable* variable) {
    791   // The variable in the declaration always resides in the current function
    792   // context.
    793   DCHECK_EQ(0, scope()->ContextChainLength(variable->scope()));
    794   if (generate_debug_code_) {
    795     // Check that we're not inside a with or catch context.
    796     __ Ldr(x1, FieldMemOperand(cp, HeapObject::kMapOffset));
    797     __ CompareRoot(x1, Heap::kWithContextMapRootIndex);
    798     __ Check(ne, kDeclarationInWithContext);
    799     __ CompareRoot(x1, Heap::kCatchContextMapRootIndex);
    800     __ Check(ne, kDeclarationInCatchContext);
    801   }
    802 }
    803 
    804 
    805 void FullCodeGenerator::VisitVariableDeclaration(
    806     VariableDeclaration* declaration) {
    807   // If it was not possible to allocate the variable at compile time, we
    808   // need to "declare" it at runtime to make sure it actually exists in the
    809   // local context.
    810   VariableProxy* proxy = declaration->proxy();
    811   VariableMode mode = declaration->mode();
    812   Variable* variable = proxy->var();
    813   bool hole_init = mode == LET || mode == CONST || mode == CONST_LEGACY;
    814 
    815   switch (variable->location()) {
    816     case Variable::UNALLOCATED:
    817       globals_->Add(variable->name(), zone());
    818       globals_->Add(variable->binding_needs_init()
    819                         ? isolate()->factory()->the_hole_value()
    820                         : isolate()->factory()->undefined_value(),
    821                     zone());
    822       break;
    823 
    824     case Variable::PARAMETER:
    825     case Variable::LOCAL:
    826       if (hole_init) {
    827         Comment cmnt(masm_, "[ VariableDeclaration");
    828         __ LoadRoot(x10, Heap::kTheHoleValueRootIndex);
    829         __ Str(x10, StackOperand(variable));
    830       }
    831       break;
    832 
    833     case Variable::CONTEXT:
    834       if (hole_init) {
    835         Comment cmnt(masm_, "[ VariableDeclaration");
    836         EmitDebugCheckDeclarationContext(variable);
    837         __ LoadRoot(x10, Heap::kTheHoleValueRootIndex);
    838         __ Str(x10, ContextMemOperand(cp, variable->index()));
    839         // No write barrier since the_hole_value is in old space.
    840         PrepareForBailoutForId(proxy->id(), NO_REGISTERS);
    841       }
    842       break;
    843 
    844     case Variable::LOOKUP: {
    845       Comment cmnt(masm_, "[ VariableDeclaration");
    846       __ Mov(x2, Operand(variable->name()));
    847       // Declaration nodes are always introduced in one of four modes.
    848       DCHECK(IsDeclaredVariableMode(mode));
    849       PropertyAttributes attr = IsImmutableVariableMode(mode) ? READ_ONLY
    850                                                               : NONE;
    851       __ Mov(x1, Smi::FromInt(attr));
    852       // Push initial value, if any.
    853       // Note: For variables we must not push an initial value (such as
    854       // 'undefined') because we may have a (legal) redeclaration and we
    855       // must not destroy the current value.
    856       if (hole_init) {
    857         __ LoadRoot(x0, Heap::kTheHoleValueRootIndex);
    858         __ Push(cp, x2, x1, x0);
    859       } else {
    860         // Pushing 0 (xzr) indicates no initial value.
    861         __ Push(cp, x2, x1, xzr);
    862       }
    863       __ CallRuntime(Runtime::kDeclareLookupSlot, 4);
    864       break;
    865     }
    866   }
    867 }
    868 
    869 
    870 void FullCodeGenerator::VisitFunctionDeclaration(
    871     FunctionDeclaration* declaration) {
    872   VariableProxy* proxy = declaration->proxy();
    873   Variable* variable = proxy->var();
    874   switch (variable->location()) {
    875     case Variable::UNALLOCATED: {
    876       globals_->Add(variable->name(), zone());
    877       Handle<SharedFunctionInfo> function =
    878           Compiler::BuildFunctionInfo(declaration->fun(), script(), info_);
    879       // Check for stack overflow exception.
    880       if (function.is_null()) return SetStackOverflow();
    881       globals_->Add(function, zone());
    882       break;
    883     }
    884 
    885     case Variable::PARAMETER:
    886     case Variable::LOCAL: {
    887       Comment cmnt(masm_, "[ Function Declaration");
    888       VisitForAccumulatorValue(declaration->fun());
    889       __ Str(result_register(), StackOperand(variable));
    890       break;
    891     }
    892 
    893     case Variable::CONTEXT: {
    894       Comment cmnt(masm_, "[ Function Declaration");
    895       EmitDebugCheckDeclarationContext(variable);
    896       VisitForAccumulatorValue(declaration->fun());
    897       __ Str(result_register(), ContextMemOperand(cp, variable->index()));
    898       int offset = Context::SlotOffset(variable->index());
    899       // We know that we have written a function, which is not a smi.
    900       __ RecordWriteContextSlot(cp,
    901                                 offset,
    902                                 result_register(),
    903                                 x2,
    904                                 kLRHasBeenSaved,
    905                                 kDontSaveFPRegs,
    906                                 EMIT_REMEMBERED_SET,
    907                                 OMIT_SMI_CHECK);
    908       PrepareForBailoutForId(proxy->id(), NO_REGISTERS);
    909       break;
    910     }
    911 
    912     case Variable::LOOKUP: {
    913       Comment cmnt(masm_, "[ Function Declaration");
    914       __ Mov(x2, Operand(variable->name()));
    915       __ Mov(x1, Smi::FromInt(NONE));
    916       __ Push(cp, x2, x1);
    917       // Push initial value for function declaration.
    918       VisitForStackValue(declaration->fun());
    919       __ CallRuntime(Runtime::kDeclareLookupSlot, 4);
    920       break;
    921     }
    922   }
    923 }
    924 
    925 
    926 void FullCodeGenerator::VisitModuleDeclaration(ModuleDeclaration* declaration) {
    927   Variable* variable = declaration->proxy()->var();
    928   DCHECK(variable->location() == Variable::CONTEXT);
    929   DCHECK(variable->interface()->IsFrozen());
    930 
    931   Comment cmnt(masm_, "[ ModuleDeclaration");
    932   EmitDebugCheckDeclarationContext(variable);
    933 
    934   // Load instance object.
    935   __ LoadContext(x1, scope_->ContextChainLength(scope_->GlobalScope()));
    936   __ Ldr(x1, ContextMemOperand(x1, variable->interface()->Index()));
    937   __ Ldr(x1, ContextMemOperand(x1, Context::EXTENSION_INDEX));
    938 
    939   // Assign it.
    940   __ Str(x1, ContextMemOperand(cp, variable->index()));
    941   // We know that we have written a module, which is not a smi.
    942   __ RecordWriteContextSlot(cp,
    943                             Context::SlotOffset(variable->index()),
    944                             x1,
    945                             x3,
    946                             kLRHasBeenSaved,
    947                             kDontSaveFPRegs,
    948                             EMIT_REMEMBERED_SET,
    949                             OMIT_SMI_CHECK);
    950   PrepareForBailoutForId(declaration->proxy()->id(), NO_REGISTERS);
    951 
    952   // Traverse info body.
    953   Visit(declaration->module());
    954 }
    955 
    956 
    957 void FullCodeGenerator::VisitImportDeclaration(ImportDeclaration* declaration) {
    958   VariableProxy* proxy = declaration->proxy();
    959   Variable* variable = proxy->var();
    960   switch (variable->location()) {
    961     case Variable::UNALLOCATED:
    962       // TODO(rossberg)
    963       break;
    964 
    965     case Variable::CONTEXT: {
    966       Comment cmnt(masm_, "[ ImportDeclaration");
    967       EmitDebugCheckDeclarationContext(variable);
    968       // TODO(rossberg)
    969       break;
    970     }
    971 
    972     case Variable::PARAMETER:
    973     case Variable::LOCAL:
    974     case Variable::LOOKUP:
    975       UNREACHABLE();
    976   }
    977 }
    978 
    979 
    980 void FullCodeGenerator::VisitExportDeclaration(ExportDeclaration* declaration) {
    981   // TODO(rossberg)
    982 }
    983 
    984 
    985 void FullCodeGenerator::DeclareGlobals(Handle<FixedArray> pairs) {
    986   // Call the runtime to declare the globals.
    987   __ Mov(x11, Operand(pairs));
    988   Register flags = xzr;
    989   if (Smi::FromInt(DeclareGlobalsFlags())) {
    990     flags = x10;
    991   __ Mov(flags, Smi::FromInt(DeclareGlobalsFlags()));
    992   }
    993   __ Push(cp, x11, flags);
    994   __ CallRuntime(Runtime::kDeclareGlobals, 3);
    995   // Return value is ignored.
    996 }
    997 
    998 
    999 void FullCodeGenerator::DeclareModules(Handle<FixedArray> descriptions) {
   1000   // Call the runtime to declare the modules.
   1001   __ Push(descriptions);
   1002   __ CallRuntime(Runtime::kDeclareModules, 1);
   1003   // Return value is ignored.
   1004 }
   1005 
   1006 
   1007 void FullCodeGenerator::VisitSwitchStatement(SwitchStatement* stmt) {
   1008   ASM_LOCATION("FullCodeGenerator::VisitSwitchStatement");
   1009   Comment cmnt(masm_, "[ SwitchStatement");
   1010   Breakable nested_statement(this, stmt);
   1011   SetStatementPosition(stmt);
   1012 
   1013   // Keep the switch value on the stack until a case matches.
   1014   VisitForStackValue(stmt->tag());
   1015   PrepareForBailoutForId(stmt->EntryId(), NO_REGISTERS);
   1016 
   1017   ZoneList<CaseClause*>* clauses = stmt->cases();
   1018   CaseClause* default_clause = NULL;  // Can occur anywhere in the list.
   1019 
   1020   Label next_test;  // Recycled for each test.
   1021   // Compile all the tests with branches to their bodies.
   1022   for (int i = 0; i < clauses->length(); i++) {
   1023     CaseClause* clause = clauses->at(i);
   1024     clause->body_target()->Unuse();
   1025 
   1026     // The default is not a test, but remember it as final fall through.
   1027     if (clause->is_default()) {
   1028       default_clause = clause;
   1029       continue;
   1030     }
   1031 
   1032     Comment cmnt(masm_, "[ Case comparison");
   1033     __ Bind(&next_test);
   1034     next_test.Unuse();
   1035 
   1036     // Compile the label expression.
   1037     VisitForAccumulatorValue(clause->label());
   1038 
   1039     // Perform the comparison as if via '==='.
   1040     __ Peek(x1, 0);   // Switch value.
   1041 
   1042     JumpPatchSite patch_site(masm_);
   1043     if (ShouldInlineSmiCase(Token::EQ_STRICT)) {
   1044       Label slow_case;
   1045       patch_site.EmitJumpIfEitherNotSmi(x0, x1, &slow_case);
   1046       __ Cmp(x1, x0);
   1047       __ B(ne, &next_test);
   1048       __ Drop(1);  // Switch value is no longer needed.
   1049       __ B(clause->body_target());
   1050       __ Bind(&slow_case);
   1051     }
   1052 
   1053     // Record position before stub call for type feedback.
   1054     SetSourcePosition(clause->position());
   1055     Handle<Code> ic =
   1056         CodeFactory::CompareIC(isolate(), Token::EQ_STRICT).code();
   1057     CallIC(ic, clause->CompareId());
   1058     patch_site.EmitPatchInfo();
   1059 
   1060     Label skip;
   1061     __ B(&skip);
   1062     PrepareForBailout(clause, TOS_REG);
   1063     __ JumpIfNotRoot(x0, Heap::kTrueValueRootIndex, &next_test);
   1064     __ Drop(1);
   1065     __ B(clause->body_target());
   1066     __ Bind(&skip);
   1067 
   1068     __ Cbnz(x0, &next_test);
   1069     __ Drop(1);  // Switch value is no longer needed.
   1070     __ B(clause->body_target());
   1071   }
   1072 
   1073   // Discard the test value and jump to the default if present, otherwise to
   1074   // the end of the statement.
   1075   __ Bind(&next_test);
   1076   __ Drop(1);  // Switch value is no longer needed.
   1077   if (default_clause == NULL) {
   1078     __ B(nested_statement.break_label());
   1079   } else {
   1080     __ B(default_clause->body_target());
   1081   }
   1082 
   1083   // Compile all the case bodies.
   1084   for (int i = 0; i < clauses->length(); i++) {
   1085     Comment cmnt(masm_, "[ Case body");
   1086     CaseClause* clause = clauses->at(i);
   1087     __ Bind(clause->body_target());
   1088     PrepareForBailoutForId(clause->EntryId(), NO_REGISTERS);
   1089     VisitStatements(clause->statements());
   1090   }
   1091 
   1092   __ Bind(nested_statement.break_label());
   1093   PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
   1094 }
   1095 
   1096 
   1097 void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   1098   ASM_LOCATION("FullCodeGenerator::VisitForInStatement");
   1099   Comment cmnt(masm_, "[ ForInStatement");
   1100   int slot = stmt->ForInFeedbackSlot();
   1101   // TODO(all): This visitor probably needs better comments and a revisit.
   1102   SetStatementPosition(stmt);
   1103 
   1104   Label loop, exit;
   1105   ForIn loop_statement(this, stmt);
   1106   increment_loop_depth();
   1107 
   1108   // Get the object to enumerate over. If the object is null or undefined, skip
   1109   // over the loop.  See ECMA-262 version 5, section 12.6.4.
   1110   VisitForAccumulatorValue(stmt->enumerable());
   1111   __ JumpIfRoot(x0, Heap::kUndefinedValueRootIndex, &exit);
   1112   Register null_value = x15;
   1113   __ LoadRoot(null_value, Heap::kNullValueRootIndex);
   1114   __ Cmp(x0, null_value);
   1115   __ B(eq, &exit);
   1116 
   1117   PrepareForBailoutForId(stmt->PrepareId(), TOS_REG);
   1118 
   1119   // Convert the object to a JS object.
   1120   Label convert, done_convert;
   1121   __ JumpIfSmi(x0, &convert);
   1122   __ JumpIfObjectType(x0, x10, x11, FIRST_SPEC_OBJECT_TYPE, &done_convert, ge);
   1123   __ Bind(&convert);
   1124   __ Push(x0);
   1125   __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
   1126   __ Bind(&done_convert);
   1127   __ Push(x0);
   1128 
   1129   // Check for proxies.
   1130   Label call_runtime;
   1131   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   1132   __ JumpIfObjectType(x0, x10, x11, LAST_JS_PROXY_TYPE, &call_runtime, le);
   1133 
   1134   // Check cache validity in generated code. This is a fast case for
   1135   // the JSObject::IsSimpleEnum cache validity checks. If we cannot
   1136   // guarantee cache validity, call the runtime system to check cache
   1137   // validity or get the property names in a fixed array.
   1138   __ CheckEnumCache(x0, null_value, x10, x11, x12, x13, &call_runtime);
   1139 
   1140   // The enum cache is valid.  Load the map of the object being
   1141   // iterated over and use the cache for the iteration.
   1142   Label use_cache;
   1143   __ Ldr(x0, FieldMemOperand(x0, HeapObject::kMapOffset));
   1144   __ B(&use_cache);
   1145 
   1146   // Get the set of properties to enumerate.
   1147   __ Bind(&call_runtime);
   1148   __ Push(x0);  // Duplicate the enumerable object on the stack.
   1149   __ CallRuntime(Runtime::kGetPropertyNamesFast, 1);
   1150 
   1151   // If we got a map from the runtime call, we can do a fast
   1152   // modification check. Otherwise, we got a fixed array, and we have
   1153   // to do a slow check.
   1154   Label fixed_array, no_descriptors;
   1155   __ Ldr(x2, FieldMemOperand(x0, HeapObject::kMapOffset));
   1156   __ JumpIfNotRoot(x2, Heap::kMetaMapRootIndex, &fixed_array);
   1157 
   1158   // We got a map in register x0. Get the enumeration cache from it.
   1159   __ Bind(&use_cache);
   1160 
   1161   __ EnumLengthUntagged(x1, x0);
   1162   __ Cbz(x1, &no_descriptors);
   1163 
   1164   __ LoadInstanceDescriptors(x0, x2);
   1165   __ Ldr(x2, FieldMemOperand(x2, DescriptorArray::kEnumCacheOffset));
   1166   __ Ldr(x2,
   1167          FieldMemOperand(x2, DescriptorArray::kEnumCacheBridgeCacheOffset));
   1168 
   1169   // Set up the four remaining stack slots.
   1170   __ SmiTag(x1);
   1171   // Map, enumeration cache, enum cache length, zero (both last as smis).
   1172   __ Push(x0, x2, x1, xzr);
   1173   __ B(&loop);
   1174 
   1175   __ Bind(&no_descriptors);
   1176   __ Drop(1);
   1177   __ B(&exit);
   1178 
   1179   // We got a fixed array in register x0. Iterate through that.
   1180   __ Bind(&fixed_array);
   1181 
   1182   __ LoadObject(x1, FeedbackVector());
   1183   __ Mov(x10, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   1184   __ Str(x10, FieldMemOperand(x1, FixedArray::OffsetOfElementAt(slot)));
   1185 
   1186   __ Mov(x1, Smi::FromInt(1));  // Smi indicates slow check.
   1187   __ Peek(x10, 0);  // Get enumerated object.
   1188   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   1189   // TODO(all): similar check was done already. Can we avoid it here?
   1190   __ CompareObjectType(x10, x11, x12, LAST_JS_PROXY_TYPE);
   1191   DCHECK(Smi::FromInt(0) == 0);
   1192   __ CzeroX(x1, le);  // Zero indicates proxy.
   1193   __ Ldr(x2, FieldMemOperand(x0, FixedArray::kLengthOffset));
   1194   // Smi and array, fixed array length (as smi) and initial index.
   1195   __ Push(x1, x0, x2, xzr);
   1196 
   1197   // Generate code for doing the condition check.
   1198   PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
   1199   __ Bind(&loop);
   1200   // Load the current count to x0, load the length to x1.
   1201   __ PeekPair(x0, x1, 0);
   1202   __ Cmp(x0, x1);  // Compare to the array length.
   1203   __ B(hs, loop_statement.break_label());
   1204 
   1205   // Get the current entry of the array into register r3.
   1206   __ Peek(x10, 2 * kXRegSize);
   1207   __ Add(x10, x10, Operand::UntagSmiAndScale(x0, kPointerSizeLog2));
   1208   __ Ldr(x3, MemOperand(x10, FixedArray::kHeaderSize - kHeapObjectTag));
   1209 
   1210   // Get the expected map from the stack or a smi in the
   1211   // permanent slow case into register x10.
   1212   __ Peek(x2, 3 * kXRegSize);
   1213 
   1214   // Check if the expected map still matches that of the enumerable.
   1215   // If not, we may have to filter the key.
   1216   Label update_each;
   1217   __ Peek(x1, 4 * kXRegSize);
   1218   __ Ldr(x11, FieldMemOperand(x1, HeapObject::kMapOffset));
   1219   __ Cmp(x11, x2);
   1220   __ B(eq, &update_each);
   1221 
   1222   // For proxies, no filtering is done.
   1223   // TODO(rossberg): What if only a prototype is a proxy? Not specified yet.
   1224   STATIC_ASSERT(kSmiTag == 0);
   1225   __ Cbz(x2, &update_each);
   1226 
   1227   // Convert the entry to a string or (smi) 0 if it isn't a property
   1228   // any more. If the property has been removed while iterating, we
   1229   // just skip it.
   1230   __ Push(x1, x3);
   1231   __ InvokeBuiltin(Builtins::FILTER_KEY, CALL_FUNCTION);
   1232   __ Mov(x3, x0);
   1233   __ Cbz(x0, loop_statement.continue_label());
   1234 
   1235   // Update the 'each' property or variable from the possibly filtered
   1236   // entry in register x3.
   1237   __ Bind(&update_each);
   1238   __ Mov(result_register(), x3);
   1239   // Perform the assignment as if via '='.
   1240   { EffectContext context(this);
   1241     EmitAssignment(stmt->each());
   1242   }
   1243 
   1244   // Generate code for the body of the loop.
   1245   Visit(stmt->body());
   1246 
   1247   // Generate code for going to the next element by incrementing
   1248   // the index (smi) stored on top of the stack.
   1249   __ Bind(loop_statement.continue_label());
   1250   // TODO(all): We could use a callee saved register to avoid popping.
   1251   __ Pop(x0);
   1252   __ Add(x0, x0, Smi::FromInt(1));
   1253   __ Push(x0);
   1254 
   1255   EmitBackEdgeBookkeeping(stmt, &loop);
   1256   __ B(&loop);
   1257 
   1258   // Remove the pointers stored on the stack.
   1259   __ Bind(loop_statement.break_label());
   1260   __ Drop(5);
   1261 
   1262   // Exit and decrement the loop depth.
   1263   PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
   1264   __ Bind(&exit);
   1265   decrement_loop_depth();
   1266 }
   1267 
   1268 
   1269 void FullCodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
   1270   Comment cmnt(masm_, "[ ForOfStatement");
   1271   SetStatementPosition(stmt);
   1272 
   1273   Iteration loop_statement(this, stmt);
   1274   increment_loop_depth();
   1275 
   1276   // var iterator = iterable[Symbol.iterator]();
   1277   VisitForEffect(stmt->assign_iterator());
   1278 
   1279   // Loop entry.
   1280   __ Bind(loop_statement.continue_label());
   1281 
   1282   // result = iterator.next()
   1283   VisitForEffect(stmt->next_result());
   1284 
   1285   // if (result.done) break;
   1286   Label result_not_done;
   1287   VisitForControl(stmt->result_done(),
   1288                   loop_statement.break_label(),
   1289                   &result_not_done,
   1290                   &result_not_done);
   1291   __ Bind(&result_not_done);
   1292 
   1293   // each = result.value
   1294   VisitForEffect(stmt->assign_each());
   1295 
   1296   // Generate code for the body of the loop.
   1297   Visit(stmt->body());
   1298 
   1299   // Check stack before looping.
   1300   PrepareForBailoutForId(stmt->BackEdgeId(), NO_REGISTERS);
   1301   EmitBackEdgeBookkeeping(stmt, loop_statement.continue_label());
   1302   __ B(loop_statement.continue_label());
   1303 
   1304   // Exit and decrement the loop depth.
   1305   PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
   1306   __ Bind(loop_statement.break_label());
   1307   decrement_loop_depth();
   1308 }
   1309 
   1310 
   1311 void FullCodeGenerator::EmitNewClosure(Handle<SharedFunctionInfo> info,
   1312                                        bool pretenure) {
   1313   // Use the fast case closure allocation code that allocates in new space for
   1314   // nested functions that don't need literals cloning. If we're running with
   1315   // the --always-opt or the --prepare-always-opt flag, we need to use the
   1316   // runtime function so that the new function we are creating here gets a
   1317   // chance to have its code optimized and doesn't just get a copy of the
   1318   // existing unoptimized code.
   1319   if (!FLAG_always_opt &&
   1320       !FLAG_prepare_always_opt &&
   1321       !pretenure &&
   1322       scope()->is_function_scope() &&
   1323       info->num_literals() == 0) {
   1324     FastNewClosureStub stub(isolate(), info->strict_mode(), info->kind());
   1325     __ Mov(x2, Operand(info));
   1326     __ CallStub(&stub);
   1327   } else {
   1328     __ Mov(x11, Operand(info));
   1329     __ LoadRoot(x10, pretenure ? Heap::kTrueValueRootIndex
   1330                                : Heap::kFalseValueRootIndex);
   1331     __ Push(cp, x11, x10);
   1332     __ CallRuntime(Runtime::kNewClosure, 3);
   1333   }
   1334   context()->Plug(x0);
   1335 }
   1336 
   1337 
   1338 void FullCodeGenerator::VisitVariableProxy(VariableProxy* expr) {
   1339   Comment cmnt(masm_, "[ VariableProxy");
   1340   EmitVariableLoad(expr);
   1341 }
   1342 
   1343 
   1344 void FullCodeGenerator::EmitLoadHomeObject(SuperReference* expr) {
   1345   Comment cnmt(masm_, "[ SuperReference ");
   1346 
   1347   __ ldr(LoadDescriptor::ReceiverRegister(),
   1348          MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   1349 
   1350   Handle<Symbol> home_object_symbol(isolate()->heap()->home_object_symbol());
   1351   __ Mov(LoadDescriptor::NameRegister(), Operand(home_object_symbol));
   1352 
   1353   CallLoadIC(NOT_CONTEXTUAL, expr->HomeObjectFeedbackId());
   1354 
   1355   __ Mov(x10, Operand(isolate()->factory()->undefined_value()));
   1356   __ cmp(x0, x10);
   1357   Label done;
   1358   __ b(&done, ne);
   1359   __ CallRuntime(Runtime::kThrowNonMethodError, 0);
   1360   __ bind(&done);
   1361 }
   1362 
   1363 
   1364 void FullCodeGenerator::EmitLoadGlobalCheckExtensions(VariableProxy* proxy,
   1365                                                       TypeofState typeof_state,
   1366                                                       Label* slow) {
   1367   Register current = cp;
   1368   Register next = x10;
   1369   Register temp = x11;
   1370 
   1371   Scope* s = scope();
   1372   while (s != NULL) {
   1373     if (s->num_heap_slots() > 0) {
   1374       if (s->calls_sloppy_eval()) {
   1375         // Check that extension is NULL.
   1376         __ Ldr(temp, ContextMemOperand(current, Context::EXTENSION_INDEX));
   1377         __ Cbnz(temp, slow);
   1378       }
   1379       // Load next context in chain.
   1380       __ Ldr(next, ContextMemOperand(current, Context::PREVIOUS_INDEX));
   1381       // Walk the rest of the chain without clobbering cp.
   1382       current = next;
   1383     }
   1384     // If no outer scope calls eval, we do not need to check more
   1385     // context extensions.
   1386     if (!s->outer_scope_calls_sloppy_eval() || s->is_eval_scope()) break;
   1387     s = s->outer_scope();
   1388   }
   1389 
   1390   if (s->is_eval_scope()) {
   1391     Label loop, fast;
   1392     __ Mov(next, current);
   1393 
   1394     __ Bind(&loop);
   1395     // Terminate at native context.
   1396     __ Ldr(temp, FieldMemOperand(next, HeapObject::kMapOffset));
   1397     __ JumpIfRoot(temp, Heap::kNativeContextMapRootIndex, &fast);
   1398     // Check that extension is NULL.
   1399     __ Ldr(temp, ContextMemOperand(next, Context::EXTENSION_INDEX));
   1400     __ Cbnz(temp, slow);
   1401     // Load next context in chain.
   1402     __ Ldr(next, ContextMemOperand(next, Context::PREVIOUS_INDEX));
   1403     __ B(&loop);
   1404     __ Bind(&fast);
   1405   }
   1406 
   1407   __ Ldr(LoadDescriptor::ReceiverRegister(), GlobalObjectMemOperand());
   1408   __ Mov(LoadDescriptor::NameRegister(), Operand(proxy->var()->name()));
   1409   if (FLAG_vector_ics) {
   1410     __ Mov(VectorLoadICDescriptor::SlotRegister(),
   1411            Smi::FromInt(proxy->VariableFeedbackSlot()));
   1412   }
   1413 
   1414   ContextualMode mode = (typeof_state == INSIDE_TYPEOF) ? NOT_CONTEXTUAL
   1415                                                         : CONTEXTUAL;
   1416   CallLoadIC(mode);
   1417 }
   1418 
   1419 
   1420 MemOperand FullCodeGenerator::ContextSlotOperandCheckExtensions(Variable* var,
   1421                                                                 Label* slow) {
   1422   DCHECK(var->IsContextSlot());
   1423   Register context = cp;
   1424   Register next = x10;
   1425   Register temp = x11;
   1426 
   1427   for (Scope* s = scope(); s != var->scope(); s = s->outer_scope()) {
   1428     if (s->num_heap_slots() > 0) {
   1429       if (s->calls_sloppy_eval()) {
   1430         // Check that extension is NULL.
   1431         __ Ldr(temp, ContextMemOperand(context, Context::EXTENSION_INDEX));
   1432         __ Cbnz(temp, slow);
   1433       }
   1434       __ Ldr(next, ContextMemOperand(context, Context::PREVIOUS_INDEX));
   1435       // Walk the rest of the chain without clobbering cp.
   1436       context = next;
   1437     }
   1438   }
   1439   // Check that last extension is NULL.
   1440   __ Ldr(temp, ContextMemOperand(context, Context::EXTENSION_INDEX));
   1441   __ Cbnz(temp, slow);
   1442 
   1443   // This function is used only for loads, not stores, so it's safe to
   1444   // return an cp-based operand (the write barrier cannot be allowed to
   1445   // destroy the cp register).
   1446   return ContextMemOperand(context, var->index());
   1447 }
   1448 
   1449 
   1450 void FullCodeGenerator::EmitDynamicLookupFastCase(VariableProxy* proxy,
   1451                                                   TypeofState typeof_state,
   1452                                                   Label* slow,
   1453                                                   Label* done) {
   1454   // Generate fast-case code for variables that might be shadowed by
   1455   // eval-introduced variables.  Eval is used a lot without
   1456   // introducing variables.  In those cases, we do not want to
   1457   // perform a runtime call for all variables in the scope
   1458   // containing the eval.
   1459   Variable* var = proxy->var();
   1460   if (var->mode() == DYNAMIC_GLOBAL) {
   1461     EmitLoadGlobalCheckExtensions(proxy, typeof_state, slow);
   1462     __ B(done);
   1463   } else if (var->mode() == DYNAMIC_LOCAL) {
   1464     Variable* local = var->local_if_not_shadowed();
   1465     __ Ldr(x0, ContextSlotOperandCheckExtensions(local, slow));
   1466     if (local->mode() == LET || local->mode() == CONST ||
   1467         local->mode() == CONST_LEGACY) {
   1468       __ JumpIfNotRoot(x0, Heap::kTheHoleValueRootIndex, done);
   1469       if (local->mode() == CONST_LEGACY) {
   1470         __ LoadRoot(x0, Heap::kUndefinedValueRootIndex);
   1471       } else {  // LET || CONST
   1472         __ Mov(x0, Operand(var->name()));
   1473         __ Push(x0);
   1474         __ CallRuntime(Runtime::kThrowReferenceError, 1);
   1475       }
   1476     }
   1477     __ B(done);
   1478   }
   1479 }
   1480 
   1481 
   1482 void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
   1483   // Record position before possible IC call.
   1484   SetSourcePosition(proxy->position());
   1485   Variable* var = proxy->var();
   1486 
   1487   // Three cases: global variables, lookup variables, and all other types of
   1488   // variables.
   1489   switch (var->location()) {
   1490     case Variable::UNALLOCATED: {
   1491       Comment cmnt(masm_, "Global variable");
   1492       __ Ldr(LoadDescriptor::ReceiverRegister(), GlobalObjectMemOperand());
   1493       __ Mov(LoadDescriptor::NameRegister(), Operand(var->name()));
   1494       if (FLAG_vector_ics) {
   1495         __ Mov(VectorLoadICDescriptor::SlotRegister(),
   1496                Smi::FromInt(proxy->VariableFeedbackSlot()));
   1497       }
   1498       CallLoadIC(CONTEXTUAL);
   1499       context()->Plug(x0);
   1500       break;
   1501     }
   1502 
   1503     case Variable::PARAMETER:
   1504     case Variable::LOCAL:
   1505     case Variable::CONTEXT: {
   1506       Comment cmnt(masm_, var->IsContextSlot()
   1507                               ? "Context variable"
   1508                               : "Stack variable");
   1509       if (var->binding_needs_init()) {
   1510         // var->scope() may be NULL when the proxy is located in eval code and
   1511         // refers to a potential outside binding. Currently those bindings are
   1512         // always looked up dynamically, i.e. in that case
   1513         //     var->location() == LOOKUP.
   1514         // always holds.
   1515         DCHECK(var->scope() != NULL);
   1516 
   1517         // Check if the binding really needs an initialization check. The check
   1518         // can be skipped in the following situation: we have a LET or CONST
   1519         // binding in harmony mode, both the Variable and the VariableProxy have
   1520         // the same declaration scope (i.e. they are both in global code, in the
   1521         // same function or in the same eval code) and the VariableProxy is in
   1522         // the source physically located after the initializer of the variable.
   1523         //
   1524         // We cannot skip any initialization checks for CONST in non-harmony
   1525         // mode because const variables may be declared but never initialized:
   1526         //   if (false) { const x; }; var y = x;
   1527         //
   1528         // The condition on the declaration scopes is a conservative check for
   1529         // nested functions that access a binding and are called before the
   1530         // binding is initialized:
   1531         //   function() { f(); let x = 1; function f() { x = 2; } }
   1532         //
   1533         bool skip_init_check;
   1534         if (var->scope()->DeclarationScope() != scope()->DeclarationScope()) {
   1535           skip_init_check = false;
   1536         } else {
   1537           // Check that we always have valid source position.
   1538           DCHECK(var->initializer_position() != RelocInfo::kNoPosition);
   1539           DCHECK(proxy->position() != RelocInfo::kNoPosition);
   1540           skip_init_check = var->mode() != CONST_LEGACY &&
   1541               var->initializer_position() < proxy->position();
   1542         }
   1543 
   1544         if (!skip_init_check) {
   1545           // Let and const need a read barrier.
   1546           GetVar(x0, var);
   1547           Label done;
   1548           __ JumpIfNotRoot(x0, Heap::kTheHoleValueRootIndex, &done);
   1549           if (var->mode() == LET || var->mode() == CONST) {
   1550             // Throw a reference error when using an uninitialized let/const
   1551             // binding in harmony mode.
   1552             __ Mov(x0, Operand(var->name()));
   1553             __ Push(x0);
   1554             __ CallRuntime(Runtime::kThrowReferenceError, 1);
   1555             __ Bind(&done);
   1556           } else {
   1557             // Uninitalized const bindings outside of harmony mode are unholed.
   1558             DCHECK(var->mode() == CONST_LEGACY);
   1559             __ LoadRoot(x0, Heap::kUndefinedValueRootIndex);
   1560             __ Bind(&done);
   1561           }
   1562           context()->Plug(x0);
   1563           break;
   1564         }
   1565       }
   1566       context()->Plug(var);
   1567       break;
   1568     }
   1569 
   1570     case Variable::LOOKUP: {
   1571       Label done, slow;
   1572       // Generate code for loading from variables potentially shadowed by
   1573       // eval-introduced variables.
   1574       EmitDynamicLookupFastCase(proxy, NOT_INSIDE_TYPEOF, &slow, &done);
   1575       __ Bind(&slow);
   1576       Comment cmnt(masm_, "Lookup variable");
   1577       __ Mov(x1, Operand(var->name()));
   1578       __ Push(cp, x1);  // Context and name.
   1579       __ CallRuntime(Runtime::kLoadLookupSlot, 2);
   1580       __ Bind(&done);
   1581       context()->Plug(x0);
   1582       break;
   1583     }
   1584   }
   1585 }
   1586 
   1587 
   1588 void FullCodeGenerator::VisitRegExpLiteral(RegExpLiteral* expr) {
   1589   Comment cmnt(masm_, "[ RegExpLiteral");
   1590   Label materialized;
   1591   // Registers will be used as follows:
   1592   // x5 = materialized value (RegExp literal)
   1593   // x4 = JS function, literals array
   1594   // x3 = literal index
   1595   // x2 = RegExp pattern
   1596   // x1 = RegExp flags
   1597   // x0 = RegExp literal clone
   1598   __ Ldr(x10, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   1599   __ Ldr(x4, FieldMemOperand(x10, JSFunction::kLiteralsOffset));
   1600   int literal_offset =
   1601       FixedArray::kHeaderSize + expr->literal_index() * kPointerSize;
   1602   __ Ldr(x5, FieldMemOperand(x4, literal_offset));
   1603   __ JumpIfNotRoot(x5, Heap::kUndefinedValueRootIndex, &materialized);
   1604 
   1605   // Create regexp literal using runtime function.
   1606   // Result will be in x0.
   1607   __ Mov(x3, Smi::FromInt(expr->literal_index()));
   1608   __ Mov(x2, Operand(expr->pattern()));
   1609   __ Mov(x1, Operand(expr->flags()));
   1610   __ Push(x4, x3, x2, x1);
   1611   __ CallRuntime(Runtime::kMaterializeRegExpLiteral, 4);
   1612   __ Mov(x5, x0);
   1613 
   1614   __ Bind(&materialized);
   1615   int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
   1616   Label allocated, runtime_allocate;
   1617   __ Allocate(size, x0, x2, x3, &runtime_allocate, TAG_OBJECT);
   1618   __ B(&allocated);
   1619 
   1620   __ Bind(&runtime_allocate);
   1621   __ Mov(x10, Smi::FromInt(size));
   1622   __ Push(x5, x10);
   1623   __ CallRuntime(Runtime::kAllocateInNewSpace, 1);
   1624   __ Pop(x5);
   1625 
   1626   __ Bind(&allocated);
   1627   // After this, registers are used as follows:
   1628   // x0: Newly allocated regexp.
   1629   // x5: Materialized regexp.
   1630   // x10, x11, x12: temps.
   1631   __ CopyFields(x0, x5, CPURegList(x10, x11, x12), size / kPointerSize);
   1632   context()->Plug(x0);
   1633 }
   1634 
   1635 
   1636 void FullCodeGenerator::EmitAccessor(Expression* expression) {
   1637   if (expression == NULL) {
   1638     __ LoadRoot(x10, Heap::kNullValueRootIndex);
   1639     __ Push(x10);
   1640   } else {
   1641     VisitForStackValue(expression);
   1642   }
   1643 }
   1644 
   1645 
   1646 void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
   1647   Comment cmnt(masm_, "[ ObjectLiteral");
   1648 
   1649   expr->BuildConstantProperties(isolate());
   1650   Handle<FixedArray> constant_properties = expr->constant_properties();
   1651   __ Ldr(x3, MemOperand(fp,  JavaScriptFrameConstants::kFunctionOffset));
   1652   __ Ldr(x3, FieldMemOperand(x3, JSFunction::kLiteralsOffset));
   1653   __ Mov(x2, Smi::FromInt(expr->literal_index()));
   1654   __ Mov(x1, Operand(constant_properties));
   1655   int flags = expr->fast_elements()
   1656       ? ObjectLiteral::kFastElements
   1657       : ObjectLiteral::kNoFlags;
   1658   flags |= expr->has_function()
   1659       ? ObjectLiteral::kHasFunction
   1660       : ObjectLiteral::kNoFlags;
   1661   __ Mov(x0, Smi::FromInt(flags));
   1662   int properties_count = constant_properties->length() / 2;
   1663   const int max_cloned_properties =
   1664       FastCloneShallowObjectStub::kMaximumClonedProperties;
   1665   if (expr->may_store_doubles() || expr->depth() > 1 ||
   1666       masm()->serializer_enabled() || flags != ObjectLiteral::kFastElements ||
   1667       properties_count > max_cloned_properties) {
   1668     __ Push(x3, x2, x1, x0);
   1669     __ CallRuntime(Runtime::kCreateObjectLiteral, 4);
   1670   } else {
   1671     FastCloneShallowObjectStub stub(isolate(), properties_count);
   1672     __ CallStub(&stub);
   1673   }
   1674 
   1675   // If result_saved is true the result is on top of the stack.  If
   1676   // result_saved is false the result is in x0.
   1677   bool result_saved = false;
   1678 
   1679   // Mark all computed expressions that are bound to a key that
   1680   // is shadowed by a later occurrence of the same key. For the
   1681   // marked expressions, no store code is emitted.
   1682   expr->CalculateEmitStore(zone());
   1683 
   1684   AccessorTable accessor_table(zone());
   1685   for (int i = 0; i < expr->properties()->length(); i++) {
   1686     ObjectLiteral::Property* property = expr->properties()->at(i);
   1687     if (property->IsCompileTimeValue()) continue;
   1688 
   1689     Literal* key = property->key();
   1690     Expression* value = property->value();
   1691     if (!result_saved) {
   1692       __ Push(x0);  // Save result on stack
   1693       result_saved = true;
   1694     }
   1695     switch (property->kind()) {
   1696       case ObjectLiteral::Property::CONSTANT:
   1697         UNREACHABLE();
   1698       case ObjectLiteral::Property::MATERIALIZED_LITERAL:
   1699         DCHECK(!CompileTimeValue::IsCompileTimeValue(property->value()));
   1700         // Fall through.
   1701       case ObjectLiteral::Property::COMPUTED:
   1702         if (key->value()->IsInternalizedString()) {
   1703           if (property->emit_store()) {
   1704             VisitForAccumulatorValue(value);
   1705             DCHECK(StoreDescriptor::ValueRegister().is(x0));
   1706             __ Mov(StoreDescriptor::NameRegister(), Operand(key->value()));
   1707             __ Peek(StoreDescriptor::ReceiverRegister(), 0);
   1708             CallStoreIC(key->LiteralFeedbackId());
   1709             PrepareForBailoutForId(key->id(), NO_REGISTERS);
   1710           } else {
   1711             VisitForEffect(value);
   1712           }
   1713           break;
   1714         }
   1715         if (property->emit_store()) {
   1716           // Duplicate receiver on stack.
   1717           __ Peek(x0, 0);
   1718           __ Push(x0);
   1719           VisitForStackValue(key);
   1720           VisitForStackValue(value);
   1721           __ Mov(x0, Smi::FromInt(SLOPPY));  // Strict mode
   1722           __ Push(x0);
   1723           __ CallRuntime(Runtime::kSetProperty, 4);
   1724         } else {
   1725           VisitForEffect(key);
   1726           VisitForEffect(value);
   1727         }
   1728         break;
   1729       case ObjectLiteral::Property::PROTOTYPE:
   1730         if (property->emit_store()) {
   1731           // Duplicate receiver on stack.
   1732           __ Peek(x0, 0);
   1733           __ Push(x0);
   1734           VisitForStackValue(value);
   1735           __ CallRuntime(Runtime::kSetPrototype, 2);
   1736         } else {
   1737           VisitForEffect(value);
   1738         }
   1739         break;
   1740       case ObjectLiteral::Property::GETTER:
   1741         accessor_table.lookup(key)->second->getter = value;
   1742         break;
   1743       case ObjectLiteral::Property::SETTER:
   1744         accessor_table.lookup(key)->second->setter = value;
   1745         break;
   1746     }
   1747   }
   1748 
   1749   // Emit code to define accessors, using only a single call to the runtime for
   1750   // each pair of corresponding getters and setters.
   1751   for (AccessorTable::Iterator it = accessor_table.begin();
   1752        it != accessor_table.end();
   1753        ++it) {
   1754       __ Peek(x10, 0);  // Duplicate receiver.
   1755       __ Push(x10);
   1756       VisitForStackValue(it->first);
   1757       EmitAccessor(it->second->getter);
   1758       EmitAccessor(it->second->setter);
   1759       __ Mov(x10, Smi::FromInt(NONE));
   1760       __ Push(x10);
   1761       __ CallRuntime(Runtime::kDefineAccessorPropertyUnchecked, 5);
   1762   }
   1763 
   1764   if (expr->has_function()) {
   1765     DCHECK(result_saved);
   1766     __ Peek(x0, 0);
   1767     __ Push(x0);
   1768     __ CallRuntime(Runtime::kToFastProperties, 1);
   1769   }
   1770 
   1771   if (result_saved) {
   1772     context()->PlugTOS();
   1773   } else {
   1774     context()->Plug(x0);
   1775   }
   1776 }
   1777 
   1778 
   1779 void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   1780   Comment cmnt(masm_, "[ ArrayLiteral");
   1781 
   1782   expr->BuildConstantElements(isolate());
   1783   int flags = (expr->depth() == 1) ? ArrayLiteral::kShallowElements
   1784                                    : ArrayLiteral::kNoFlags;
   1785 
   1786   ZoneList<Expression*>* subexprs = expr->values();
   1787   int length = subexprs->length();
   1788   Handle<FixedArray> constant_elements = expr->constant_elements();
   1789   DCHECK_EQ(2, constant_elements->length());
   1790   ElementsKind constant_elements_kind =
   1791       static_cast<ElementsKind>(Smi::cast(constant_elements->get(0))->value());
   1792   bool has_fast_elements = IsFastObjectElementsKind(constant_elements_kind);
   1793   Handle<FixedArrayBase> constant_elements_values(
   1794       FixedArrayBase::cast(constant_elements->get(1)));
   1795 
   1796   AllocationSiteMode allocation_site_mode = TRACK_ALLOCATION_SITE;
   1797   if (has_fast_elements && !FLAG_allocation_site_pretenuring) {
   1798     // If the only customer of allocation sites is transitioning, then
   1799     // we can turn it off if we don't have anywhere else to transition to.
   1800     allocation_site_mode = DONT_TRACK_ALLOCATION_SITE;
   1801   }
   1802 
   1803   __ Ldr(x3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   1804   __ Ldr(x3, FieldMemOperand(x3, JSFunction::kLiteralsOffset));
   1805   __ Mov(x2, Smi::FromInt(expr->literal_index()));
   1806   __ Mov(x1, Operand(constant_elements));
   1807   if (expr->depth() > 1 || length > JSObject::kInitialMaxFastElementArray) {
   1808     __ Mov(x0, Smi::FromInt(flags));
   1809     __ Push(x3, x2, x1, x0);
   1810     __ CallRuntime(Runtime::kCreateArrayLiteral, 4);
   1811   } else {
   1812     FastCloneShallowArrayStub stub(isolate(), allocation_site_mode);
   1813     __ CallStub(&stub);
   1814   }
   1815 
   1816   bool result_saved = false;  // Is the result saved to the stack?
   1817 
   1818   // Emit code to evaluate all the non-constant subexpressions and to store
   1819   // them into the newly cloned array.
   1820   for (int i = 0; i < length; i++) {
   1821     Expression* subexpr = subexprs->at(i);
   1822     // If the subexpression is a literal or a simple materialized literal it
   1823     // is already set in the cloned array.
   1824     if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;
   1825 
   1826     if (!result_saved) {
   1827       __ Mov(x1, Smi::FromInt(expr->literal_index()));
   1828       __ Push(x0, x1);
   1829       result_saved = true;
   1830     }
   1831     VisitForAccumulatorValue(subexpr);
   1832 
   1833     if (IsFastObjectElementsKind(constant_elements_kind)) {
   1834       int offset = FixedArray::kHeaderSize + (i * kPointerSize);
   1835       __ Peek(x6, kPointerSize);  // Copy of array literal.
   1836       __ Ldr(x1, FieldMemOperand(x6, JSObject::kElementsOffset));
   1837       __ Str(result_register(), FieldMemOperand(x1, offset));
   1838       // Update the write barrier for the array store.
   1839       __ RecordWriteField(x1, offset, result_register(), x10,
   1840                           kLRHasBeenSaved, kDontSaveFPRegs,
   1841                           EMIT_REMEMBERED_SET, INLINE_SMI_CHECK);
   1842     } else {
   1843       __ Mov(x3, Smi::FromInt(i));
   1844       StoreArrayLiteralElementStub stub(isolate());
   1845       __ CallStub(&stub);
   1846     }
   1847 
   1848     PrepareForBailoutForId(expr->GetIdForElement(i), NO_REGISTERS);
   1849   }
   1850 
   1851   if (result_saved) {
   1852     __ Drop(1);   // literal index
   1853     context()->PlugTOS();
   1854   } else {
   1855     context()->Plug(x0);
   1856   }
   1857 }
   1858 
   1859 
   1860 void FullCodeGenerator::VisitAssignment(Assignment* expr) {
   1861   DCHECK(expr->target()->IsValidReferenceExpression());
   1862 
   1863   Comment cmnt(masm_, "[ Assignment");
   1864 
   1865   // Left-hand side can only be a property, a global or a (parameter or local)
   1866   // slot.
   1867   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   1868   LhsKind assign_type = VARIABLE;
   1869   Property* property = expr->target()->AsProperty();
   1870   if (property != NULL) {
   1871     assign_type = (property->key()->IsPropertyName())
   1872         ? NAMED_PROPERTY
   1873         : KEYED_PROPERTY;
   1874   }
   1875 
   1876   // Evaluate LHS expression.
   1877   switch (assign_type) {
   1878     case VARIABLE:
   1879       // Nothing to do here.
   1880       break;
   1881     case NAMED_PROPERTY:
   1882       if (expr->is_compound()) {
   1883         // We need the receiver both on the stack and in the register.
   1884         VisitForStackValue(property->obj());
   1885         __ Peek(LoadDescriptor::ReceiverRegister(), 0);
   1886       } else {
   1887         VisitForStackValue(property->obj());
   1888       }
   1889       break;
   1890     case KEYED_PROPERTY:
   1891       if (expr->is_compound()) {
   1892         VisitForStackValue(property->obj());
   1893         VisitForStackValue(property->key());
   1894         __ Peek(LoadDescriptor::ReceiverRegister(), 1 * kPointerSize);
   1895         __ Peek(LoadDescriptor::NameRegister(), 0);
   1896       } else {
   1897         VisitForStackValue(property->obj());
   1898         VisitForStackValue(property->key());
   1899       }
   1900       break;
   1901   }
   1902 
   1903   // For compound assignments we need another deoptimization point after the
   1904   // variable/property load.
   1905   if (expr->is_compound()) {
   1906     { AccumulatorValueContext context(this);
   1907       switch (assign_type) {
   1908         case VARIABLE:
   1909           EmitVariableLoad(expr->target()->AsVariableProxy());
   1910           PrepareForBailout(expr->target(), TOS_REG);
   1911           break;
   1912         case NAMED_PROPERTY:
   1913           EmitNamedPropertyLoad(property);
   1914           PrepareForBailoutForId(property->LoadId(), TOS_REG);
   1915           break;
   1916         case KEYED_PROPERTY:
   1917           EmitKeyedPropertyLoad(property);
   1918           PrepareForBailoutForId(property->LoadId(), TOS_REG);
   1919           break;
   1920       }
   1921     }
   1922 
   1923     Token::Value op = expr->binary_op();
   1924     __ Push(x0);  // Left operand goes on the stack.
   1925     VisitForAccumulatorValue(expr->value());
   1926 
   1927     OverwriteMode mode = expr->value()->ResultOverwriteAllowed()
   1928         ? OVERWRITE_RIGHT
   1929         : NO_OVERWRITE;
   1930     SetSourcePosition(expr->position() + 1);
   1931     AccumulatorValueContext context(this);
   1932     if (ShouldInlineSmiCase(op)) {
   1933       EmitInlineSmiBinaryOp(expr->binary_operation(),
   1934                             op,
   1935                             mode,
   1936                             expr->target(),
   1937                             expr->value());
   1938     } else {
   1939       EmitBinaryOp(expr->binary_operation(), op, mode);
   1940     }
   1941 
   1942     // Deoptimization point in case the binary operation may have side effects.
   1943     PrepareForBailout(expr->binary_operation(), TOS_REG);
   1944   } else {
   1945     VisitForAccumulatorValue(expr->value());
   1946   }
   1947 
   1948   // Record source position before possible IC call.
   1949   SetSourcePosition(expr->position());
   1950 
   1951   // Store the value.
   1952   switch (assign_type) {
   1953     case VARIABLE:
   1954       EmitVariableAssignment(expr->target()->AsVariableProxy()->var(),
   1955                              expr->op());
   1956       PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   1957       context()->Plug(x0);
   1958       break;
   1959     case NAMED_PROPERTY:
   1960       EmitNamedPropertyAssignment(expr);
   1961       break;
   1962     case KEYED_PROPERTY:
   1963       EmitKeyedPropertyAssignment(expr);
   1964       break;
   1965   }
   1966 }
   1967 
   1968 
   1969 void FullCodeGenerator::EmitNamedPropertyLoad(Property* prop) {
   1970   SetSourcePosition(prop->position());
   1971   Literal* key = prop->key()->AsLiteral();
   1972   DCHECK(!prop->IsSuperAccess());
   1973 
   1974   __ Mov(LoadDescriptor::NameRegister(), Operand(key->value()));
   1975   if (FLAG_vector_ics) {
   1976     __ Mov(VectorLoadICDescriptor::SlotRegister(),
   1977            Smi::FromInt(prop->PropertyFeedbackSlot()));
   1978     CallLoadIC(NOT_CONTEXTUAL);
   1979   } else {
   1980     CallLoadIC(NOT_CONTEXTUAL, prop->PropertyFeedbackId());
   1981   }
   1982 }
   1983 
   1984 
   1985 void FullCodeGenerator::EmitNamedSuperPropertyLoad(Property* prop) {
   1986   SetSourcePosition(prop->position());
   1987   Literal* key = prop->key()->AsLiteral();
   1988   DCHECK(!key->value()->IsSmi());
   1989   DCHECK(prop->IsSuperAccess());
   1990 
   1991   SuperReference* super_ref = prop->obj()->AsSuperReference();
   1992   EmitLoadHomeObject(super_ref);
   1993   __ Push(x0);
   1994   VisitForStackValue(super_ref->this_var());
   1995   __ Push(key->value());
   1996   __ CallRuntime(Runtime::kLoadFromSuper, 3);
   1997 }
   1998 
   1999 
   2000 void FullCodeGenerator::EmitKeyedPropertyLoad(Property* prop) {
   2001   SetSourcePosition(prop->position());
   2002   // Call keyed load IC. It has arguments key and receiver in r0 and r1.
   2003   Handle<Code> ic = CodeFactory::KeyedLoadIC(isolate()).code();
   2004   if (FLAG_vector_ics) {
   2005     __ Mov(VectorLoadICDescriptor::SlotRegister(),
   2006            Smi::FromInt(prop->PropertyFeedbackSlot()));
   2007     CallIC(ic);
   2008   } else {
   2009     CallIC(ic, prop->PropertyFeedbackId());
   2010   }
   2011 }
   2012 
   2013 
   2014 void FullCodeGenerator::EmitInlineSmiBinaryOp(BinaryOperation* expr,
   2015                                               Token::Value op,
   2016                                               OverwriteMode mode,
   2017                                               Expression* left_expr,
   2018                                               Expression* right_expr) {
   2019   Label done, both_smis, stub_call;
   2020 
   2021   // Get the arguments.
   2022   Register left = x1;
   2023   Register right = x0;
   2024   Register result = x0;
   2025   __ Pop(left);
   2026 
   2027   // Perform combined smi check on both operands.
   2028   __ Orr(x10, left, right);
   2029   JumpPatchSite patch_site(masm_);
   2030   patch_site.EmitJumpIfSmi(x10, &both_smis);
   2031 
   2032   __ Bind(&stub_call);
   2033 
   2034   Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), op, mode).code();
   2035   {
   2036     Assembler::BlockPoolsScope scope(masm_);
   2037     CallIC(code, expr->BinaryOperationFeedbackId());
   2038     patch_site.EmitPatchInfo();
   2039   }
   2040   __ B(&done);
   2041 
   2042   __ Bind(&both_smis);
   2043   // Smi case. This code works in the same way as the smi-smi case in the type
   2044   // recording binary operation stub, see
   2045   // BinaryOpStub::GenerateSmiSmiOperation for comments.
   2046   // TODO(all): That doesn't exist any more. Where are the comments?
   2047   //
   2048   // The set of operations that needs to be supported here is controlled by
   2049   // FullCodeGenerator::ShouldInlineSmiCase().
   2050   switch (op) {
   2051     case Token::SAR:
   2052       __ Ubfx(right, right, kSmiShift, 5);
   2053       __ Asr(result, left, right);
   2054       __ Bic(result, result, kSmiShiftMask);
   2055       break;
   2056     case Token::SHL:
   2057       __ Ubfx(right, right, kSmiShift, 5);
   2058       __ Lsl(result, left, right);
   2059       break;
   2060     case Token::SHR:
   2061       // If `left >>> right` >= 0x80000000, the result is not representable in a
   2062       // signed 32-bit smi.
   2063       __ Ubfx(right, right, kSmiShift, 5);
   2064       __ Lsr(x10, left, right);
   2065       __ Tbnz(x10, kXSignBit, &stub_call);
   2066       __ Bic(result, x10, kSmiShiftMask);
   2067       break;
   2068     case Token::ADD:
   2069       __ Adds(x10, left, right);
   2070       __ B(vs, &stub_call);
   2071       __ Mov(result, x10);
   2072       break;
   2073     case Token::SUB:
   2074       __ Subs(x10, left, right);
   2075       __ B(vs, &stub_call);
   2076       __ Mov(result, x10);
   2077       break;
   2078     case Token::MUL: {
   2079       Label not_minus_zero, done;
   2080       STATIC_ASSERT(static_cast<unsigned>(kSmiShift) == (kXRegSizeInBits / 2));
   2081       STATIC_ASSERT(kSmiTag == 0);
   2082       __ Smulh(x10, left, right);
   2083       __ Cbnz(x10, &not_minus_zero);
   2084       __ Eor(x11, left, right);
   2085       __ Tbnz(x11, kXSignBit, &stub_call);
   2086       __ Mov(result, x10);
   2087       __ B(&done);
   2088       __ Bind(&not_minus_zero);
   2089       __ Cls(x11, x10);
   2090       __ Cmp(x11, kXRegSizeInBits - kSmiShift);
   2091       __ B(lt, &stub_call);
   2092       __ SmiTag(result, x10);
   2093       __ Bind(&done);
   2094       break;
   2095     }
   2096     case Token::BIT_OR:
   2097       __ Orr(result, left, right);
   2098       break;
   2099     case Token::BIT_AND:
   2100       __ And(result, left, right);
   2101       break;
   2102     case Token::BIT_XOR:
   2103       __ Eor(result, left, right);
   2104       break;
   2105     default:
   2106       UNREACHABLE();
   2107   }
   2108 
   2109   __ Bind(&done);
   2110   context()->Plug(x0);
   2111 }
   2112 
   2113 
   2114 void FullCodeGenerator::EmitBinaryOp(BinaryOperation* expr,
   2115                                      Token::Value op,
   2116                                      OverwriteMode mode) {
   2117   __ Pop(x1);
   2118   Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), op, mode).code();
   2119   JumpPatchSite patch_site(masm_);    // Unbound, signals no inlined smi code.
   2120   {
   2121     Assembler::BlockPoolsScope scope(masm_);
   2122     CallIC(code, expr->BinaryOperationFeedbackId());
   2123     patch_site.EmitPatchInfo();
   2124   }
   2125   context()->Plug(x0);
   2126 }
   2127 
   2128 
   2129 void FullCodeGenerator::EmitAssignment(Expression* expr) {
   2130   DCHECK(expr->IsValidReferenceExpression());
   2131 
   2132   // Left-hand side can only be a property, a global or a (parameter or local)
   2133   // slot.
   2134   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   2135   LhsKind assign_type = VARIABLE;
   2136   Property* prop = expr->AsProperty();
   2137   if (prop != NULL) {
   2138     assign_type = (prop->key()->IsPropertyName())
   2139         ? NAMED_PROPERTY
   2140         : KEYED_PROPERTY;
   2141   }
   2142 
   2143   switch (assign_type) {
   2144     case VARIABLE: {
   2145       Variable* var = expr->AsVariableProxy()->var();
   2146       EffectContext context(this);
   2147       EmitVariableAssignment(var, Token::ASSIGN);
   2148       break;
   2149     }
   2150     case NAMED_PROPERTY: {
   2151       __ Push(x0);  // Preserve value.
   2152       VisitForAccumulatorValue(prop->obj());
   2153       // TODO(all): We could introduce a VisitForRegValue(reg, expr) to avoid
   2154       // this copy.
   2155       __ Mov(StoreDescriptor::ReceiverRegister(), x0);
   2156       __ Pop(StoreDescriptor::ValueRegister());  // Restore value.
   2157       __ Mov(StoreDescriptor::NameRegister(),
   2158              Operand(prop->key()->AsLiteral()->value()));
   2159       CallStoreIC();
   2160       break;
   2161     }
   2162     case KEYED_PROPERTY: {
   2163       __ Push(x0);  // Preserve value.
   2164       VisitForStackValue(prop->obj());
   2165       VisitForAccumulatorValue(prop->key());
   2166       __ Mov(StoreDescriptor::NameRegister(), x0);
   2167       __ Pop(StoreDescriptor::ReceiverRegister(),
   2168              StoreDescriptor::ValueRegister());
   2169       Handle<Code> ic =
   2170           CodeFactory::KeyedStoreIC(isolate(), strict_mode()).code();
   2171       CallIC(ic);
   2172       break;
   2173     }
   2174   }
   2175   context()->Plug(x0);
   2176 }
   2177 
   2178 
   2179 void FullCodeGenerator::EmitStoreToStackLocalOrContextSlot(
   2180     Variable* var, MemOperand location) {
   2181   __ Str(result_register(), location);
   2182   if (var->IsContextSlot()) {
   2183     // RecordWrite may destroy all its register arguments.
   2184     __ Mov(x10, result_register());
   2185     int offset = Context::SlotOffset(var->index());
   2186     __ RecordWriteContextSlot(
   2187         x1, offset, x10, x11, kLRHasBeenSaved, kDontSaveFPRegs);
   2188   }
   2189 }
   2190 
   2191 
   2192 void FullCodeGenerator::EmitVariableAssignment(Variable* var,
   2193                                                Token::Value op) {
   2194   ASM_LOCATION("FullCodeGenerator::EmitVariableAssignment");
   2195   if (var->IsUnallocated()) {
   2196     // Global var, const, or let.
   2197     __ Mov(StoreDescriptor::NameRegister(), Operand(var->name()));
   2198     __ Ldr(StoreDescriptor::ReceiverRegister(), GlobalObjectMemOperand());
   2199     CallStoreIC();
   2200 
   2201   } else if (op == Token::INIT_CONST_LEGACY) {
   2202     // Const initializers need a write barrier.
   2203     DCHECK(!var->IsParameter());  // No const parameters.
   2204     if (var->IsLookupSlot()) {
   2205       __ Mov(x1, Operand(var->name()));
   2206       __ Push(x0, cp, x1);
   2207       __ CallRuntime(Runtime::kInitializeLegacyConstLookupSlot, 3);
   2208     } else {
   2209       DCHECK(var->IsStackLocal() || var->IsContextSlot());
   2210       Label skip;
   2211       MemOperand location = VarOperand(var, x1);
   2212       __ Ldr(x10, location);
   2213       __ JumpIfNotRoot(x10, Heap::kTheHoleValueRootIndex, &skip);
   2214       EmitStoreToStackLocalOrContextSlot(var, location);
   2215       __ Bind(&skip);
   2216     }
   2217 
   2218   } else if (var->mode() == LET && op != Token::INIT_LET) {
   2219     // Non-initializing assignment to let variable needs a write barrier.
   2220     DCHECK(!var->IsLookupSlot());
   2221     DCHECK(var->IsStackAllocated() || var->IsContextSlot());
   2222     Label assign;
   2223     MemOperand location = VarOperand(var, x1);
   2224     __ Ldr(x10, location);
   2225     __ JumpIfNotRoot(x10, Heap::kTheHoleValueRootIndex, &assign);
   2226     __ Mov(x10, Operand(var->name()));
   2227     __ Push(x10);
   2228     __ CallRuntime(Runtime::kThrowReferenceError, 1);
   2229     // Perform the assignment.
   2230     __ Bind(&assign);
   2231     EmitStoreToStackLocalOrContextSlot(var, location);
   2232 
   2233   } else if (!var->is_const_mode() || op == Token::INIT_CONST) {
   2234     if (var->IsLookupSlot()) {
   2235       // Assignment to var.
   2236       __ Mov(x11, Operand(var->name()));
   2237       __ Mov(x10, Smi::FromInt(strict_mode()));
   2238       // jssp[0]  : mode.
   2239       // jssp[8]  : name.
   2240       // jssp[16] : context.
   2241       // jssp[24] : value.
   2242       __ Push(x0, cp, x11, x10);
   2243       __ CallRuntime(Runtime::kStoreLookupSlot, 4);
   2244     } else {
   2245       // Assignment to var or initializing assignment to let/const in harmony
   2246       // mode.
   2247       DCHECK(var->IsStackAllocated() || var->IsContextSlot());
   2248       MemOperand location = VarOperand(var, x1);
   2249       if (FLAG_debug_code && op == Token::INIT_LET) {
   2250         __ Ldr(x10, location);
   2251         __ CompareRoot(x10, Heap::kTheHoleValueRootIndex);
   2252         __ Check(eq, kLetBindingReInitialization);
   2253       }
   2254       EmitStoreToStackLocalOrContextSlot(var, location);
   2255     }
   2256   }
   2257   // Non-initializing assignments to consts are ignored.
   2258 }
   2259 
   2260 
   2261 void FullCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) {
   2262   ASM_LOCATION("FullCodeGenerator::EmitNamedPropertyAssignment");
   2263   // Assignment to a property, using a named store IC.
   2264   Property* prop = expr->target()->AsProperty();
   2265   DCHECK(prop != NULL);
   2266   DCHECK(prop->key()->IsLiteral());
   2267 
   2268   // Record source code position before IC call.
   2269   SetSourcePosition(expr->position());
   2270   __ Mov(StoreDescriptor::NameRegister(),
   2271          Operand(prop->key()->AsLiteral()->value()));
   2272   __ Pop(StoreDescriptor::ReceiverRegister());
   2273   CallStoreIC(expr->AssignmentFeedbackId());
   2274 
   2275   PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   2276   context()->Plug(x0);
   2277 }
   2278 
   2279 
   2280 void FullCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) {
   2281   ASM_LOCATION("FullCodeGenerator::EmitKeyedPropertyAssignment");
   2282   // Assignment to a property, using a keyed store IC.
   2283 
   2284   // Record source code position before IC call.
   2285   SetSourcePosition(expr->position());
   2286   // TODO(all): Could we pass this in registers rather than on the stack?
   2287   __ Pop(StoreDescriptor::NameRegister(), StoreDescriptor::ReceiverRegister());
   2288   DCHECK(StoreDescriptor::ValueRegister().is(x0));
   2289 
   2290   Handle<Code> ic = CodeFactory::KeyedStoreIC(isolate(), strict_mode()).code();
   2291   CallIC(ic, expr->AssignmentFeedbackId());
   2292 
   2293   PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   2294   context()->Plug(x0);
   2295 }
   2296 
   2297 
   2298 void FullCodeGenerator::VisitProperty(Property* expr) {
   2299   Comment cmnt(masm_, "[ Property");
   2300   Expression* key = expr->key();
   2301 
   2302   if (key->IsPropertyName()) {
   2303     if (!expr->IsSuperAccess()) {
   2304       VisitForAccumulatorValue(expr->obj());
   2305       __ Move(LoadDescriptor::ReceiverRegister(), x0);
   2306       EmitNamedPropertyLoad(expr);
   2307     } else {
   2308       EmitNamedSuperPropertyLoad(expr);
   2309     }
   2310     PrepareForBailoutForId(expr->LoadId(), TOS_REG);
   2311     context()->Plug(x0);
   2312   } else {
   2313     VisitForStackValue(expr->obj());
   2314     VisitForAccumulatorValue(expr->key());
   2315     __ Move(LoadDescriptor::NameRegister(), x0);
   2316     __ Pop(LoadDescriptor::ReceiverRegister());
   2317     EmitKeyedPropertyLoad(expr);
   2318     context()->Plug(x0);
   2319   }
   2320 }
   2321 
   2322 
   2323 void FullCodeGenerator::CallIC(Handle<Code> code,
   2324                                TypeFeedbackId ast_id) {
   2325   ic_total_count_++;
   2326   // All calls must have a predictable size in full-codegen code to ensure that
   2327   // the debugger can patch them correctly.
   2328   __ Call(code, RelocInfo::CODE_TARGET, ast_id);
   2329 }
   2330 
   2331 
   2332 // Code common for calls using the IC.
   2333 void FullCodeGenerator::EmitCallWithLoadIC(Call* expr) {
   2334   Expression* callee = expr->expression();
   2335 
   2336   CallICState::CallType call_type =
   2337       callee->IsVariableProxy() ? CallICState::FUNCTION : CallICState::METHOD;
   2338 
   2339   // Get the target function.
   2340   if (call_type == CallICState::FUNCTION) {
   2341     { StackValueContext context(this);
   2342       EmitVariableLoad(callee->AsVariableProxy());
   2343       PrepareForBailout(callee, NO_REGISTERS);
   2344     }
   2345     // Push undefined as receiver. This is patched in the method prologue if it
   2346     // is a sloppy mode method.
   2347     __ Push(isolate()->factory()->undefined_value());
   2348   } else {
   2349     // Load the function from the receiver.
   2350     DCHECK(callee->IsProperty());
   2351     DCHECK(!callee->AsProperty()->IsSuperAccess());
   2352     __ Peek(LoadDescriptor::ReceiverRegister(), 0);
   2353     EmitNamedPropertyLoad(callee->AsProperty());
   2354     PrepareForBailoutForId(callee->AsProperty()->LoadId(), TOS_REG);
   2355     // Push the target function under the receiver.
   2356     __ Pop(x10);
   2357     __ Push(x0, x10);
   2358   }
   2359 
   2360   EmitCall(expr, call_type);
   2361 }
   2362 
   2363 
   2364 void FullCodeGenerator::EmitSuperCallWithLoadIC(Call* expr) {
   2365   Expression* callee = expr->expression();
   2366   DCHECK(callee->IsProperty());
   2367   Property* prop = callee->AsProperty();
   2368   DCHECK(prop->IsSuperAccess());
   2369 
   2370   SetSourcePosition(prop->position());
   2371   Literal* key = prop->key()->AsLiteral();
   2372   DCHECK(!key->value()->IsSmi());
   2373 
   2374   // Load the function from the receiver.
   2375   const Register scratch = x10;
   2376   SuperReference* super_ref = callee->AsProperty()->obj()->AsSuperReference();
   2377   EmitLoadHomeObject(super_ref);
   2378   __ Push(x0);
   2379   VisitForAccumulatorValue(super_ref->this_var());
   2380   __ Push(x0);
   2381   __ Peek(scratch, kPointerSize);
   2382   __ Push(scratch, x0);
   2383   __ Push(key->value());
   2384 
   2385   // Stack here:
   2386   //  - home_object
   2387   //  - this (receiver)
   2388   //  - home_object <-- LoadFromSuper will pop here and below.
   2389   //  - this (receiver)
   2390   //  - key
   2391   __ CallRuntime(Runtime::kLoadFromSuper, 3);
   2392 
   2393   // Replace home_object with target function.
   2394   __ Poke(x0, kPointerSize);
   2395 
   2396   // Stack here:
   2397   // - target function
   2398   // - this (receiver)
   2399   EmitCall(expr, CallICState::METHOD);
   2400 }
   2401 
   2402 
   2403 // Code common for calls using the IC.
   2404 void FullCodeGenerator::EmitKeyedCallWithLoadIC(Call* expr,
   2405                                                 Expression* key) {
   2406   // Load the key.
   2407   VisitForAccumulatorValue(key);
   2408 
   2409   Expression* callee = expr->expression();
   2410 
   2411   // Load the function from the receiver.
   2412   DCHECK(callee->IsProperty());
   2413   __ Peek(LoadDescriptor::ReceiverRegister(), 0);
   2414   __ Move(LoadDescriptor::NameRegister(), x0);
   2415   EmitKeyedPropertyLoad(callee->AsProperty());
   2416   PrepareForBailoutForId(callee->AsProperty()->LoadId(), TOS_REG);
   2417 
   2418   // Push the target function under the receiver.
   2419   __ Pop(x10);
   2420   __ Push(x0, x10);
   2421 
   2422   EmitCall(expr, CallICState::METHOD);
   2423 }
   2424 
   2425 
   2426 void FullCodeGenerator::EmitCall(Call* expr, CallICState::CallType call_type) {
   2427   // Load the arguments.
   2428   ZoneList<Expression*>* args = expr->arguments();
   2429   int arg_count = args->length();
   2430   { PreservePositionScope scope(masm()->positions_recorder());
   2431     for (int i = 0; i < arg_count; i++) {
   2432       VisitForStackValue(args->at(i));
   2433     }
   2434   }
   2435   // Record source position of the IC call.
   2436   SetSourcePosition(expr->position());
   2437 
   2438   Handle<Code> ic = CallIC::initialize_stub(
   2439       isolate(), arg_count, call_type);
   2440   __ Mov(x3, Smi::FromInt(expr->CallFeedbackSlot()));
   2441   __ Peek(x1, (arg_count + 1) * kXRegSize);
   2442   // Don't assign a type feedback id to the IC, since type feedback is provided
   2443   // by the vector above.
   2444   CallIC(ic);
   2445 
   2446   RecordJSReturnSite(expr);
   2447   // Restore context register.
   2448   __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   2449   context()->DropAndPlug(1, x0);
   2450 }
   2451 
   2452 
   2453 void FullCodeGenerator::EmitResolvePossiblyDirectEval(int arg_count) {
   2454   ASM_LOCATION("FullCodeGenerator::EmitResolvePossiblyDirectEval");
   2455   // Prepare to push a copy of the first argument or undefined if it doesn't
   2456   // exist.
   2457   if (arg_count > 0) {
   2458     __ Peek(x9, arg_count * kXRegSize);
   2459   } else {
   2460     __ LoadRoot(x9, Heap::kUndefinedValueRootIndex);
   2461   }
   2462 
   2463   __ Ldr(x10, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   2464   // Prepare to push the receiver of the enclosing function.
   2465   int receiver_offset = 2 + info_->scope()->num_parameters();
   2466   __ Ldr(x11, MemOperand(fp, receiver_offset * kPointerSize));
   2467 
   2468   // Prepare to push the language mode.
   2469   __ Mov(x12, Smi::FromInt(strict_mode()));
   2470   // Prepare to push the start position of the scope the calls resides in.
   2471   __ Mov(x13, Smi::FromInt(scope()->start_position()));
   2472 
   2473   // Push.
   2474   __ Push(x9, x10, x11, x12, x13);
   2475 
   2476   // Do the runtime call.
   2477   __ CallRuntime(Runtime::kResolvePossiblyDirectEval, 6);
   2478 }
   2479 
   2480 
   2481 void FullCodeGenerator::VisitCall(Call* expr) {
   2482 #ifdef DEBUG
   2483   // We want to verify that RecordJSReturnSite gets called on all paths
   2484   // through this function.  Avoid early returns.
   2485   expr->return_is_recorded_ = false;
   2486 #endif
   2487 
   2488   Comment cmnt(masm_, "[ Call");
   2489   Expression* callee = expr->expression();
   2490   Call::CallType call_type = expr->GetCallType(isolate());
   2491 
   2492   if (call_type == Call::POSSIBLY_EVAL_CALL) {
   2493     // In a call to eval, we first call RuntimeHidden_ResolvePossiblyDirectEval
   2494     // to resolve the function we need to call and the receiver of the
   2495     // call.  Then we call the resolved function using the given
   2496     // arguments.
   2497     ZoneList<Expression*>* args = expr->arguments();
   2498     int arg_count = args->length();
   2499 
   2500     {
   2501       PreservePositionScope pos_scope(masm()->positions_recorder());
   2502       VisitForStackValue(callee);
   2503       __ LoadRoot(x10, Heap::kUndefinedValueRootIndex);
   2504       __ Push(x10);  // Reserved receiver slot.
   2505 
   2506       // Push the arguments.
   2507       for (int i = 0; i < arg_count; i++) {
   2508         VisitForStackValue(args->at(i));
   2509       }
   2510 
   2511       // Push a copy of the function (found below the arguments) and
   2512       // resolve eval.
   2513       __ Peek(x10, (arg_count + 1) * kPointerSize);
   2514       __ Push(x10);
   2515       EmitResolvePossiblyDirectEval(arg_count);
   2516 
   2517       // The runtime call returns a pair of values in x0 (function) and
   2518       // x1 (receiver). Touch up the stack with the right values.
   2519       __ PokePair(x1, x0, arg_count * kPointerSize);
   2520     }
   2521 
   2522     // Record source position for debugger.
   2523     SetSourcePosition(expr->position());
   2524 
   2525     // Call the evaluated function.
   2526     CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
   2527     __ Peek(x1, (arg_count + 1) * kXRegSize);
   2528     __ CallStub(&stub);
   2529     RecordJSReturnSite(expr);
   2530     // Restore context register.
   2531     __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   2532     context()->DropAndPlug(1, x0);
   2533 
   2534   } else if (call_type == Call::GLOBAL_CALL) {
   2535     EmitCallWithLoadIC(expr);
   2536 
   2537   } else if (call_type == Call::LOOKUP_SLOT_CALL) {
   2538     // Call to a lookup slot (dynamically introduced variable).
   2539     VariableProxy* proxy = callee->AsVariableProxy();
   2540     Label slow, done;
   2541 
   2542     { PreservePositionScope scope(masm()->positions_recorder());
   2543       // Generate code for loading from variables potentially shadowed
   2544       // by eval-introduced variables.
   2545       EmitDynamicLookupFastCase(proxy, NOT_INSIDE_TYPEOF, &slow, &done);
   2546     }
   2547 
   2548     __ Bind(&slow);
   2549     // Call the runtime to find the function to call (returned in x0)
   2550     // and the object holding it (returned in x1).
   2551     __ Mov(x10, Operand(proxy->name()));
   2552     __ Push(context_register(), x10);
   2553     __ CallRuntime(Runtime::kLoadLookupSlot, 2);
   2554     __ Push(x0, x1);  // Receiver, function.
   2555 
   2556     // If fast case code has been generated, emit code to push the
   2557     // function and receiver and have the slow path jump around this
   2558     // code.
   2559     if (done.is_linked()) {
   2560       Label call;
   2561       __ B(&call);
   2562       __ Bind(&done);
   2563       // Push function.
   2564       // The receiver is implicitly the global receiver. Indicate this
   2565       // by passing the undefined to the call function stub.
   2566       __ LoadRoot(x1, Heap::kUndefinedValueRootIndex);
   2567       __ Push(x0, x1);
   2568       __ Bind(&call);
   2569     }
   2570 
   2571     // The receiver is either the global receiver or an object found
   2572     // by LoadContextSlot.
   2573     EmitCall(expr);
   2574   } else if (call_type == Call::PROPERTY_CALL) {
   2575     Property* property = callee->AsProperty();
   2576     bool is_named_call = property->key()->IsPropertyName();
   2577     // super.x() is handled in EmitCallWithLoadIC.
   2578     if (property->IsSuperAccess() && is_named_call) {
   2579       EmitSuperCallWithLoadIC(expr);
   2580     } else {
   2581       {
   2582         PreservePositionScope scope(masm()->positions_recorder());
   2583         VisitForStackValue(property->obj());
   2584       }
   2585       if (is_named_call) {
   2586         EmitCallWithLoadIC(expr);
   2587       } else {
   2588         EmitKeyedCallWithLoadIC(expr, property->key());
   2589       }
   2590     }
   2591   } else {
   2592     DCHECK(call_type == Call::OTHER_CALL);
   2593     // Call to an arbitrary expression not handled specially above.
   2594     { PreservePositionScope scope(masm()->positions_recorder());
   2595       VisitForStackValue(callee);
   2596     }
   2597     __ LoadRoot(x1, Heap::kUndefinedValueRootIndex);
   2598     __ Push(x1);
   2599     // Emit function call.
   2600     EmitCall(expr);
   2601   }
   2602 
   2603 #ifdef DEBUG
   2604   // RecordJSReturnSite should have been called.
   2605   DCHECK(expr->return_is_recorded_);
   2606 #endif
   2607 }
   2608 
   2609 
   2610 void FullCodeGenerator::VisitCallNew(CallNew* expr) {
   2611   Comment cmnt(masm_, "[ CallNew");
   2612   // According to ECMA-262, section 11.2.2, page 44, the function
   2613   // expression in new calls must be evaluated before the
   2614   // arguments.
   2615 
   2616   // Push constructor on the stack.  If it's not a function it's used as
   2617   // receiver for CALL_NON_FUNCTION, otherwise the value on the stack is
   2618   // ignored.
   2619   VisitForStackValue(expr->expression());
   2620 
   2621   // Push the arguments ("left-to-right") on the stack.
   2622   ZoneList<Expression*>* args = expr->arguments();
   2623   int arg_count = args->length();
   2624   for (int i = 0; i < arg_count; i++) {
   2625     VisitForStackValue(args->at(i));
   2626   }
   2627 
   2628   // Call the construct call builtin that handles allocation and
   2629   // constructor invocation.
   2630   SetSourcePosition(expr->position());
   2631 
   2632   // Load function and argument count into x1 and x0.
   2633   __ Mov(x0, arg_count);
   2634   __ Peek(x1, arg_count * kXRegSize);
   2635 
   2636   // Record call targets in unoptimized code.
   2637   if (FLAG_pretenuring_call_new) {
   2638     EnsureSlotContainsAllocationSite(expr->AllocationSiteFeedbackSlot());
   2639     DCHECK(expr->AllocationSiteFeedbackSlot() ==
   2640            expr->CallNewFeedbackSlot() + 1);
   2641   }
   2642 
   2643   __ LoadObject(x2, FeedbackVector());
   2644   __ Mov(x3, Smi::FromInt(expr->CallNewFeedbackSlot()));
   2645 
   2646   CallConstructStub stub(isolate(), RECORD_CONSTRUCTOR_TARGET);
   2647   __ Call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
   2648   PrepareForBailoutForId(expr->ReturnId(), TOS_REG);
   2649   context()->Plug(x0);
   2650 }
   2651 
   2652 
   2653 void FullCodeGenerator::EmitIsSmi(CallRuntime* expr) {
   2654   ZoneList<Expression*>* args = expr->arguments();
   2655   DCHECK(args->length() == 1);
   2656 
   2657   VisitForAccumulatorValue(args->at(0));
   2658 
   2659   Label materialize_true, materialize_false;
   2660   Label* if_true = NULL;
   2661   Label* if_false = NULL;
   2662   Label* fall_through = NULL;
   2663   context()->PrepareTest(&materialize_true, &materialize_false,
   2664                          &if_true, &if_false, &fall_through);
   2665 
   2666   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2667   __ TestAndSplit(x0, kSmiTagMask, if_true, if_false, fall_through);
   2668 
   2669   context()->Plug(if_true, if_false);
   2670 }
   2671 
   2672 
   2673 void FullCodeGenerator::EmitIsNonNegativeSmi(CallRuntime* expr) {
   2674   ZoneList<Expression*>* args = expr->arguments();
   2675   DCHECK(args->length() == 1);
   2676 
   2677   VisitForAccumulatorValue(args->at(0));
   2678 
   2679   Label materialize_true, materialize_false;
   2680   Label* if_true = NULL;
   2681   Label* if_false = NULL;
   2682   Label* fall_through = NULL;
   2683   context()->PrepareTest(&materialize_true, &materialize_false,
   2684                          &if_true, &if_false, &fall_through);
   2685 
   2686   uint64_t sign_mask = V8_UINT64_C(1) << (kSmiShift + kSmiValueSize - 1);
   2687 
   2688   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2689   __ TestAndSplit(x0, kSmiTagMask | sign_mask, if_true, if_false, fall_through);
   2690 
   2691   context()->Plug(if_true, if_false);
   2692 }
   2693 
   2694 
   2695 void FullCodeGenerator::EmitIsObject(CallRuntime* expr) {
   2696   ZoneList<Expression*>* args = expr->arguments();
   2697   DCHECK(args->length() == 1);
   2698 
   2699   VisitForAccumulatorValue(args->at(0));
   2700 
   2701   Label materialize_true, materialize_false;
   2702   Label* if_true = NULL;
   2703   Label* if_false = NULL;
   2704   Label* fall_through = NULL;
   2705   context()->PrepareTest(&materialize_true, &materialize_false,
   2706                          &if_true, &if_false, &fall_through);
   2707 
   2708   __ JumpIfSmi(x0, if_false);
   2709   __ JumpIfRoot(x0, Heap::kNullValueRootIndex, if_true);
   2710   __ Ldr(x10, FieldMemOperand(x0, HeapObject::kMapOffset));
   2711   // Undetectable objects behave like undefined when tested with typeof.
   2712   __ Ldrb(x11, FieldMemOperand(x10, Map::kBitFieldOffset));
   2713   __ Tbnz(x11, Map::kIsUndetectable, if_false);
   2714   __ Ldrb(x12, FieldMemOperand(x10, Map::kInstanceTypeOffset));
   2715   __ Cmp(x12, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE);
   2716   __ B(lt, if_false);
   2717   __ Cmp(x12, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
   2718   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2719   Split(le, if_true, if_false, fall_through);
   2720 
   2721   context()->Plug(if_true, if_false);
   2722 }
   2723 
   2724 
   2725 void FullCodeGenerator::EmitIsSpecObject(CallRuntime* expr) {
   2726   ZoneList<Expression*>* args = expr->arguments();
   2727   DCHECK(args->length() == 1);
   2728 
   2729   VisitForAccumulatorValue(args->at(0));
   2730 
   2731   Label materialize_true, materialize_false;
   2732   Label* if_true = NULL;
   2733   Label* if_false = NULL;
   2734   Label* fall_through = NULL;
   2735   context()->PrepareTest(&materialize_true, &materialize_false,
   2736                          &if_true, &if_false, &fall_through);
   2737 
   2738   __ JumpIfSmi(x0, if_false);
   2739   __ CompareObjectType(x0, x10, x11, FIRST_SPEC_OBJECT_TYPE);
   2740   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2741   Split(ge, if_true, if_false, fall_through);
   2742 
   2743   context()->Plug(if_true, if_false);
   2744 }
   2745 
   2746 
   2747 void FullCodeGenerator::EmitIsUndetectableObject(CallRuntime* expr) {
   2748   ASM_LOCATION("FullCodeGenerator::EmitIsUndetectableObject");
   2749   ZoneList<Expression*>* args = expr->arguments();
   2750   DCHECK(args->length() == 1);
   2751 
   2752   VisitForAccumulatorValue(args->at(0));
   2753 
   2754   Label materialize_true, materialize_false;
   2755   Label* if_true = NULL;
   2756   Label* if_false = NULL;
   2757   Label* fall_through = NULL;
   2758   context()->PrepareTest(&materialize_true, &materialize_false,
   2759                          &if_true, &if_false, &fall_through);
   2760 
   2761   __ JumpIfSmi(x0, if_false);
   2762   __ Ldr(x10, FieldMemOperand(x0, HeapObject::kMapOffset));
   2763   __ Ldrb(x11, FieldMemOperand(x10, Map::kBitFieldOffset));
   2764   __ Tst(x11, 1 << Map::kIsUndetectable);
   2765   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2766   Split(ne, if_true, if_false, fall_through);
   2767 
   2768   context()->Plug(if_true, if_false);
   2769 }
   2770 
   2771 
   2772 void FullCodeGenerator::EmitIsStringWrapperSafeForDefaultValueOf(
   2773     CallRuntime* expr) {
   2774   ZoneList<Expression*>* args = expr->arguments();
   2775   DCHECK(args->length() == 1);
   2776   VisitForAccumulatorValue(args->at(0));
   2777 
   2778   Label materialize_true, materialize_false, skip_lookup;
   2779   Label* if_true = NULL;
   2780   Label* if_false = NULL;
   2781   Label* fall_through = NULL;
   2782   context()->PrepareTest(&materialize_true, &materialize_false,
   2783                          &if_true, &if_false, &fall_through);
   2784 
   2785   Register object = x0;
   2786   __ AssertNotSmi(object);
   2787 
   2788   Register map = x10;
   2789   Register bitfield2 = x11;
   2790   __ Ldr(map, FieldMemOperand(object, HeapObject::kMapOffset));
   2791   __ Ldrb(bitfield2, FieldMemOperand(map, Map::kBitField2Offset));
   2792   __ Tbnz(bitfield2, Map::kStringWrapperSafeForDefaultValueOf, &skip_lookup);
   2793 
   2794   // Check for fast case object. Generate false result for slow case object.
   2795   Register props = x12;
   2796   Register props_map = x12;
   2797   Register hash_table_map = x13;
   2798   __ Ldr(props, FieldMemOperand(object, JSObject::kPropertiesOffset));
   2799   __ Ldr(props_map, FieldMemOperand(props, HeapObject::kMapOffset));
   2800   __ LoadRoot(hash_table_map, Heap::kHashTableMapRootIndex);
   2801   __ Cmp(props_map, hash_table_map);
   2802   __ B(eq, if_false);
   2803 
   2804   // Look for valueOf name in the descriptor array, and indicate false if found.
   2805   // Since we omit an enumeration index check, if it is added via a transition
   2806   // that shares its descriptor array, this is a false positive.
   2807   Label loop, done;
   2808 
   2809   // Skip loop if no descriptors are valid.
   2810   Register descriptors = x12;
   2811   Register descriptors_length = x13;
   2812   __ NumberOfOwnDescriptors(descriptors_length, map);
   2813   __ Cbz(descriptors_length, &done);
   2814 
   2815   __ LoadInstanceDescriptors(map, descriptors);
   2816 
   2817   // Calculate the end of the descriptor array.
   2818   Register descriptors_end = x14;
   2819   __ Mov(x15, DescriptorArray::kDescriptorSize);
   2820   __ Mul(descriptors_length, descriptors_length, x15);
   2821   // Calculate location of the first key name.
   2822   __ Add(descriptors, descriptors,
   2823          DescriptorArray::kFirstOffset - kHeapObjectTag);
   2824   // Calculate the end of the descriptor array.
   2825   __ Add(descriptors_end, descriptors,
   2826          Operand(descriptors_length, LSL, kPointerSizeLog2));
   2827 
   2828   // Loop through all the keys in the descriptor array. If one of these is the
   2829   // string "valueOf" the result is false.
   2830   Register valueof_string = x1;
   2831   int descriptor_size = DescriptorArray::kDescriptorSize * kPointerSize;
   2832   __ Mov(valueof_string, Operand(isolate()->factory()->value_of_string()));
   2833   __ Bind(&loop);
   2834   __ Ldr(x15, MemOperand(descriptors, descriptor_size, PostIndex));
   2835   __ Cmp(x15, valueof_string);
   2836   __ B(eq, if_false);
   2837   __ Cmp(descriptors, descriptors_end);
   2838   __ B(ne, &loop);
   2839 
   2840   __ Bind(&done);
   2841 
   2842   // Set the bit in the map to indicate that there is no local valueOf field.
   2843   __ Ldrb(x2, FieldMemOperand(map, Map::kBitField2Offset));
   2844   __ Orr(x2, x2, 1 << Map::kStringWrapperSafeForDefaultValueOf);
   2845   __ Strb(x2, FieldMemOperand(map, Map::kBitField2Offset));
   2846 
   2847   __ Bind(&skip_lookup);
   2848 
   2849   // If a valueOf property is not found on the object check that its prototype
   2850   // is the unmodified String prototype. If not result is false.
   2851   Register prototype = x1;
   2852   Register global_idx = x2;
   2853   Register native_context = x2;
   2854   Register string_proto = x3;
   2855   Register proto_map = x4;
   2856   __ Ldr(prototype, FieldMemOperand(map, Map::kPrototypeOffset));
   2857   __ JumpIfSmi(prototype, if_false);
   2858   __ Ldr(proto_map, FieldMemOperand(prototype, HeapObject::kMapOffset));
   2859   __ Ldr(global_idx, GlobalObjectMemOperand());
   2860   __ Ldr(native_context,
   2861          FieldMemOperand(global_idx, GlobalObject::kNativeContextOffset));
   2862   __ Ldr(string_proto,
   2863          ContextMemOperand(native_context,
   2864                            Context::STRING_FUNCTION_PROTOTYPE_MAP_INDEX));
   2865   __ Cmp(proto_map, string_proto);
   2866 
   2867   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2868   Split(eq, if_true, if_false, fall_through);
   2869 
   2870   context()->Plug(if_true, if_false);
   2871 }
   2872 
   2873 
   2874 void FullCodeGenerator::EmitIsFunction(CallRuntime* expr) {
   2875   ZoneList<Expression*>* args = expr->arguments();
   2876   DCHECK(args->length() == 1);
   2877 
   2878   VisitForAccumulatorValue(args->at(0));
   2879 
   2880   Label materialize_true, materialize_false;
   2881   Label* if_true = NULL;
   2882   Label* if_false = NULL;
   2883   Label* fall_through = NULL;
   2884   context()->PrepareTest(&materialize_true, &materialize_false,
   2885                          &if_true, &if_false, &fall_through);
   2886 
   2887   __ JumpIfSmi(x0, if_false);
   2888   __ CompareObjectType(x0, x10, x11, JS_FUNCTION_TYPE);
   2889   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2890   Split(eq, if_true, if_false, fall_through);
   2891 
   2892   context()->Plug(if_true, if_false);
   2893 }
   2894 
   2895 
   2896 void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
   2897   ZoneList<Expression*>* args = expr->arguments();
   2898   DCHECK(args->length() == 1);
   2899 
   2900   VisitForAccumulatorValue(args->at(0));
   2901 
   2902   Label materialize_true, materialize_false;
   2903   Label* if_true = NULL;
   2904   Label* if_false = NULL;
   2905   Label* fall_through = NULL;
   2906   context()->PrepareTest(&materialize_true, &materialize_false,
   2907                          &if_true, &if_false, &fall_through);
   2908 
   2909   // Only a HeapNumber can be -0.0, so return false if we have something else.
   2910   __ JumpIfNotHeapNumber(x0, if_false, DO_SMI_CHECK);
   2911 
   2912   // Test the bit pattern.
   2913   __ Ldr(x10, FieldMemOperand(x0, HeapNumber::kValueOffset));
   2914   __ Cmp(x10, 1);   // Set V on 0x8000000000000000.
   2915 
   2916   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2917   Split(vs, if_true, if_false, fall_through);
   2918 
   2919   context()->Plug(if_true, if_false);
   2920 }
   2921 
   2922 
   2923 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   2924   ZoneList<Expression*>* args = expr->arguments();
   2925   DCHECK(args->length() == 1);
   2926 
   2927   VisitForAccumulatorValue(args->at(0));
   2928 
   2929   Label materialize_true, materialize_false;
   2930   Label* if_true = NULL;
   2931   Label* if_false = NULL;
   2932   Label* fall_through = NULL;
   2933   context()->PrepareTest(&materialize_true, &materialize_false,
   2934                          &if_true, &if_false, &fall_through);
   2935 
   2936   __ JumpIfSmi(x0, if_false);
   2937   __ CompareObjectType(x0, x10, x11, JS_ARRAY_TYPE);
   2938   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2939   Split(eq, if_true, if_false, fall_through);
   2940 
   2941   context()->Plug(if_true, if_false);
   2942 }
   2943 
   2944 
   2945 void FullCodeGenerator::EmitIsRegExp(CallRuntime* expr) {
   2946   ZoneList<Expression*>* args = expr->arguments();
   2947   DCHECK(args->length() == 1);
   2948 
   2949   VisitForAccumulatorValue(args->at(0));
   2950 
   2951   Label materialize_true, materialize_false;
   2952   Label* if_true = NULL;
   2953   Label* if_false = NULL;
   2954   Label* fall_through = NULL;
   2955   context()->PrepareTest(&materialize_true, &materialize_false,
   2956                          &if_true, &if_false, &fall_through);
   2957 
   2958   __ JumpIfSmi(x0, if_false);
   2959   __ CompareObjectType(x0, x10, x11, JS_REGEXP_TYPE);
   2960   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2961   Split(eq, if_true, if_false, fall_through);
   2962 
   2963   context()->Plug(if_true, if_false);
   2964 }
   2965 
   2966 
   2967 
   2968 void FullCodeGenerator::EmitIsConstructCall(CallRuntime* expr) {
   2969   DCHECK(expr->arguments()->length() == 0);
   2970 
   2971   Label materialize_true, materialize_false;
   2972   Label* if_true = NULL;
   2973   Label* if_false = NULL;
   2974   Label* fall_through = NULL;
   2975   context()->PrepareTest(&materialize_true, &materialize_false,
   2976                          &if_true, &if_false, &fall_through);
   2977 
   2978   // Get the frame pointer for the calling frame.
   2979   __ Ldr(x2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   2980 
   2981   // Skip the arguments adaptor frame if it exists.
   2982   Label check_frame_marker;
   2983   __ Ldr(x1, MemOperand(x2, StandardFrameConstants::kContextOffset));
   2984   __ Cmp(x1, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
   2985   __ B(ne, &check_frame_marker);
   2986   __ Ldr(x2, MemOperand(x2, StandardFrameConstants::kCallerFPOffset));
   2987 
   2988   // Check the marker in the calling frame.
   2989   __ Bind(&check_frame_marker);
   2990   __ Ldr(x1, MemOperand(x2, StandardFrameConstants::kMarkerOffset));
   2991   __ Cmp(x1, Smi::FromInt(StackFrame::CONSTRUCT));
   2992   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   2993   Split(eq, if_true, if_false, fall_through);
   2994 
   2995   context()->Plug(if_true, if_false);
   2996 }
   2997 
   2998 
   2999 void FullCodeGenerator::EmitObjectEquals(CallRuntime* expr) {
   3000   ZoneList<Expression*>* args = expr->arguments();
   3001   DCHECK(args->length() == 2);
   3002 
   3003   // Load the two objects into registers and perform the comparison.
   3004   VisitForStackValue(args->at(0));
   3005   VisitForAccumulatorValue(args->at(1));
   3006 
   3007   Label materialize_true, materialize_false;
   3008   Label* if_true = NULL;
   3009   Label* if_false = NULL;
   3010   Label* fall_through = NULL;
   3011   context()->PrepareTest(&materialize_true, &materialize_false,
   3012                          &if_true, &if_false, &fall_through);
   3013 
   3014   __ Pop(x1);
   3015   __ Cmp(x0, x1);
   3016   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   3017   Split(eq, if_true, if_false, fall_through);
   3018 
   3019   context()->Plug(if_true, if_false);
   3020 }
   3021 
   3022 
   3023 void FullCodeGenerator::EmitArguments(CallRuntime* expr) {
   3024   ZoneList<Expression*>* args = expr->arguments();
   3025   DCHECK(args->length() == 1);
   3026 
   3027   // ArgumentsAccessStub expects the key in x1.
   3028   VisitForAccumulatorValue(args->at(0));
   3029   __ Mov(x1, x0);
   3030   __ Mov(x0, Smi::FromInt(info_->scope()->num_parameters()));
   3031   ArgumentsAccessStub stub(isolate(), ArgumentsAccessStub::READ_ELEMENT);
   3032   __ CallStub(&stub);
   3033   context()->Plug(x0);
   3034 }
   3035 
   3036 
   3037 void FullCodeGenerator::EmitArgumentsLength(CallRuntime* expr) {
   3038   DCHECK(expr->arguments()->length() == 0);
   3039   Label exit;
   3040   // Get the number of formal parameters.
   3041   __ Mov(x0, Smi::FromInt(info_->scope()->num_parameters()));
   3042 
   3043   // Check if the calling frame is an arguments adaptor frame.
   3044   __ Ldr(x12, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   3045   __ Ldr(x13, MemOperand(x12, StandardFrameConstants::kContextOffset));
   3046   __ Cmp(x13, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
   3047   __ B(ne, &exit);
   3048 
   3049   // Arguments adaptor case: Read the arguments length from the
   3050   // adaptor frame.
   3051   __ Ldr(x0, MemOperand(x12, ArgumentsAdaptorFrameConstants::kLengthOffset));
   3052 
   3053   __ Bind(&exit);
   3054   context()->Plug(x0);
   3055 }
   3056 
   3057 
   3058 void FullCodeGenerator::EmitClassOf(CallRuntime* expr) {
   3059   ASM_LOCATION("FullCodeGenerator::EmitClassOf");
   3060   ZoneList<Expression*>* args = expr->arguments();
   3061   DCHECK(args->length() == 1);
   3062   Label done, null, function, non_function_constructor;
   3063 
   3064   VisitForAccumulatorValue(args->at(0));
   3065 
   3066   // If the object is a smi, we return null.
   3067   __ JumpIfSmi(x0, &null);
   3068 
   3069   // Check that the object is a JS object but take special care of JS
   3070   // functions to make sure they have 'Function' as their class.
   3071   // Assume that there are only two callable types, and one of them is at
   3072   // either end of the type range for JS object types. Saves extra comparisons.
   3073   STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
   3074   __ CompareObjectType(x0, x10, x11, FIRST_SPEC_OBJECT_TYPE);
   3075   // x10: object's map.
   3076   // x11: object's type.
   3077   __ B(lt, &null);
   3078   STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
   3079                 FIRST_SPEC_OBJECT_TYPE + 1);
   3080   __ B(eq, &function);
   3081 
   3082   __ Cmp(x11, LAST_SPEC_OBJECT_TYPE);
   3083   STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
   3084                 LAST_SPEC_OBJECT_TYPE - 1);
   3085   __ B(eq, &function);
   3086   // Assume that there is no larger type.
   3087   STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE == LAST_TYPE - 1);
   3088 
   3089   // Check if the constructor in the map is a JS function.
   3090   __ Ldr(x12, FieldMemOperand(x10, Map::kConstructorOffset));
   3091   __ JumpIfNotObjectType(x12, x13, x14, JS_FUNCTION_TYPE,
   3092                          &non_function_constructor);
   3093 
   3094   // x12 now contains the constructor function. Grab the
   3095   // instance class name from there.
   3096   __ Ldr(x13, FieldMemOperand(x12, JSFunction::kSharedFunctionInfoOffset));
   3097   __ Ldr(x0,
   3098          FieldMemOperand(x13, SharedFunctionInfo::kInstanceClassNameOffset));
   3099   __ B(&done);
   3100 
   3101   // Functions have class 'Function'.
   3102   __ Bind(&function);
   3103   __ LoadRoot(x0, Heap::kFunction_stringRootIndex);
   3104   __ B(&done);
   3105 
   3106   // Objects with a non-function constructor have class 'Object'.
   3107   __ Bind(&non_function_constructor);
   3108   __ LoadRoot(x0, Heap::kObject_stringRootIndex);
   3109   __ B(&done);
   3110 
   3111   // Non-JS objects have class null.
   3112   __ Bind(&null);
   3113   __ LoadRoot(x0, Heap::kNullValueRootIndex);
   3114 
   3115   // All done.
   3116   __ Bind(&done);
   3117 
   3118   context()->Plug(x0);
   3119 }
   3120 
   3121 
   3122 void FullCodeGenerator::EmitSubString(CallRuntime* expr) {
   3123   // Load the arguments on the stack and call the stub.
   3124   SubStringStub stub(isolate());
   3125   ZoneList<Expression*>* args = expr->arguments();
   3126   DCHECK(args->length() == 3);
   3127   VisitForStackValue(args->at(0));
   3128   VisitForStackValue(args->at(1));
   3129   VisitForStackValue(args->at(2));
   3130   __ CallStub(&stub);
   3131   context()->Plug(x0);
   3132 }
   3133 
   3134 
   3135 void FullCodeGenerator::EmitRegExpExec(CallRuntime* expr) {
   3136   // Load the arguments on the stack and call the stub.
   3137   RegExpExecStub stub(isolate());
   3138   ZoneList<Expression*>* args = expr->arguments();
   3139   DCHECK(args->length() == 4);
   3140   VisitForStackValue(args->at(0));
   3141   VisitForStackValue(args->at(1));
   3142   VisitForStackValue(args->at(2));
   3143   VisitForStackValue(args->at(3));
   3144   __ CallStub(&stub);
   3145   context()->Plug(x0);
   3146 }
   3147 
   3148 
   3149 void FullCodeGenerator::EmitValueOf(CallRuntime* expr) {
   3150   ASM_LOCATION("FullCodeGenerator::EmitValueOf");
   3151   ZoneList<Expression*>* args = expr->arguments();
   3152   DCHECK(args->length() == 1);
   3153   VisitForAccumulatorValue(args->at(0));  // Load the object.
   3154 
   3155   Label done;
   3156   // If the object is a smi return the object.
   3157   __ JumpIfSmi(x0, &done);
   3158   // If the object is not a value type, return the object.
   3159   __ JumpIfNotObjectType(x0, x10, x11, JS_VALUE_TYPE, &done);
   3160   __ Ldr(x0, FieldMemOperand(x0, JSValue::kValueOffset));
   3161 
   3162   __ Bind(&done);
   3163   context()->Plug(x0);
   3164 }
   3165 
   3166 
   3167 void FullCodeGenerator::EmitDateField(CallRuntime* expr) {
   3168   ZoneList<Expression*>* args = expr->arguments();
   3169   DCHECK(args->length() == 2);
   3170   DCHECK_NE(NULL, args->at(1)->AsLiteral());
   3171   Smi* index = Smi::cast(*(args->at(1)->AsLiteral()->value()));
   3172 
   3173   VisitForAccumulatorValue(args->at(0));  // Load the object.
   3174 
   3175   Label runtime, done, not_date_object;
   3176   Register object = x0;
   3177   Register result = x0;
   3178   Register stamp_addr = x10;
   3179   Register stamp_cache = x11;
   3180 
   3181   __ JumpIfSmi(object, &not_date_object);
   3182   __ JumpIfNotObjectType(object, x10, x10, JS_DATE_TYPE, &not_date_object);
   3183 
   3184   if (index->value() == 0) {
   3185     __ Ldr(result, FieldMemOperand(object, JSDate::kValueOffset));
   3186     __ B(&done);
   3187   } else {
   3188     if (index->value() < JSDate::kFirstUncachedField) {
   3189       ExternalReference stamp = ExternalReference::date_cache_stamp(isolate());
   3190       __ Mov(x10, stamp);
   3191       __ Ldr(stamp_addr, MemOperand(x10));
   3192       __ Ldr(stamp_cache, FieldMemOperand(object, JSDate::kCacheStampOffset));
   3193       __ Cmp(stamp_addr, stamp_cache);
   3194       __ B(ne, &runtime);
   3195       __ Ldr(result, FieldMemOperand(object, JSDate::kValueOffset +
   3196                                              kPointerSize * index->value()));
   3197       __ B(&done);
   3198     }
   3199 
   3200     __ Bind(&runtime);
   3201     __ Mov(x1, index);
   3202     __ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2);
   3203     __ B(&done);
   3204   }
   3205 
   3206   __ Bind(&not_date_object);
   3207   __ CallRuntime(Runtime::kThrowNotDateError, 0);
   3208   __ Bind(&done);
   3209   context()->Plug(x0);
   3210 }
   3211 
   3212 
   3213 void FullCodeGenerator::EmitOneByteSeqStringSetChar(CallRuntime* expr) {
   3214   ZoneList<Expression*>* args = expr->arguments();
   3215   DCHECK_EQ(3, args->length());
   3216 
   3217   Register string = x0;
   3218   Register index = x1;
   3219   Register value = x2;
   3220   Register scratch = x10;
   3221 
   3222   VisitForStackValue(args->at(0));        // index
   3223   VisitForStackValue(args->at(1));        // value
   3224   VisitForAccumulatorValue(args->at(2));  // string
   3225   __ Pop(value, index);
   3226 
   3227   if (FLAG_debug_code) {
   3228     __ AssertSmi(value, kNonSmiValue);
   3229     __ AssertSmi(index, kNonSmiIndex);
   3230     static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
   3231     __ EmitSeqStringSetCharCheck(string, index, kIndexIsSmi, scratch,
   3232                                  one_byte_seq_type);
   3233   }
   3234 
   3235   __ Add(scratch, string, SeqOneByteString::kHeaderSize - kHeapObjectTag);
   3236   __ SmiUntag(value);
   3237   __ SmiUntag(index);
   3238   __ Strb(value, MemOperand(scratch, index));
   3239   context()->Plug(string);
   3240 }
   3241 
   3242 
   3243 void FullCodeGenerator::EmitTwoByteSeqStringSetChar(CallRuntime* expr) {
   3244   ZoneList<Expression*>* args = expr->arguments();
   3245   DCHECK_EQ(3, args->length());
   3246 
   3247   Register string = x0;
   3248   Register index = x1;
   3249   Register value = x2;
   3250   Register scratch = x10;
   3251 
   3252   VisitForStackValue(args->at(0));        // index
   3253   VisitForStackValue(args->at(1));        // value
   3254   VisitForAccumulatorValue(args->at(2));  // string
   3255   __ Pop(value, index);
   3256 
   3257   if (FLAG_debug_code) {
   3258     __ AssertSmi(value, kNonSmiValue);
   3259     __ AssertSmi(index, kNonSmiIndex);
   3260     static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
   3261     __ EmitSeqStringSetCharCheck(string, index, kIndexIsSmi, scratch,
   3262                                  two_byte_seq_type);
   3263   }
   3264 
   3265   __ Add(scratch, string, SeqTwoByteString::kHeaderSize - kHeapObjectTag);
   3266   __ SmiUntag(value);
   3267   __ SmiUntag(index);
   3268   __ Strh(value, MemOperand(scratch, index, LSL, 1));
   3269   context()->Plug(string);
   3270 }
   3271 
   3272 
   3273 void FullCodeGenerator::EmitMathPow(CallRuntime* expr) {
   3274   // Load the arguments on the stack and call the MathPow stub.
   3275   ZoneList<Expression*>* args = expr->arguments();
   3276   DCHECK(args->length() == 2);
   3277   VisitForStackValue(args->at(0));
   3278   VisitForStackValue(args->at(1));
   3279   MathPowStub stub(isolate(), MathPowStub::ON_STACK);
   3280   __ CallStub(&stub);
   3281   context()->Plug(x0);
   3282 }
   3283 
   3284 
   3285 void FullCodeGenerator::EmitSetValueOf(CallRuntime* expr) {
   3286   ZoneList<Expression*>* args = expr->arguments();
   3287   DCHECK(args->length() == 2);
   3288   VisitForStackValue(args->at(0));  // Load the object.
   3289   VisitForAccumulatorValue(args->at(1));  // Load the value.
   3290   __ Pop(x1);
   3291   // x0 = value.
   3292   // x1 = object.
   3293 
   3294   Label done;
   3295   // If the object is a smi, return the value.
   3296   __ JumpIfSmi(x1, &done);
   3297 
   3298   // If the object is not a value type, return the value.
   3299   __ JumpIfNotObjectType(x1, x10, x11, JS_VALUE_TYPE, &done);
   3300 
   3301   // Store the value.
   3302   __ Str(x0, FieldMemOperand(x1, JSValue::kValueOffset));
   3303   // Update the write barrier. Save the value as it will be
   3304   // overwritten by the write barrier code and is needed afterward.
   3305   __ Mov(x10, x0);
   3306   __ RecordWriteField(
   3307       x1, JSValue::kValueOffset, x10, x11, kLRHasBeenSaved, kDontSaveFPRegs);
   3308 
   3309   __ Bind(&done);
   3310   context()->Plug(x0);
   3311 }
   3312 
   3313 
   3314 void FullCodeGenerator::EmitNumberToString(CallRuntime* expr) {
   3315   ZoneList<Expression*>* args = expr->arguments();
   3316   DCHECK_EQ(args->length(), 1);
   3317 
   3318   // Load the argument into x0 and call the stub.
   3319   VisitForAccumulatorValue(args->at(0));
   3320 
   3321   NumberToStringStub stub(isolate());
   3322   __ CallStub(&stub);
   3323   context()->Plug(x0);
   3324 }
   3325 
   3326 
   3327 void FullCodeGenerator::EmitStringCharFromCode(CallRuntime* expr) {
   3328   ZoneList<Expression*>* args = expr->arguments();
   3329   DCHECK(args->length() == 1);
   3330 
   3331   VisitForAccumulatorValue(args->at(0));
   3332 
   3333   Label done;
   3334   Register code = x0;
   3335   Register result = x1;
   3336 
   3337   StringCharFromCodeGenerator generator(code, result);
   3338   generator.GenerateFast(masm_);
   3339   __ B(&done);
   3340 
   3341   NopRuntimeCallHelper call_helper;
   3342   generator.GenerateSlow(masm_, call_helper);
   3343 
   3344   __ Bind(&done);
   3345   context()->Plug(result);
   3346 }
   3347 
   3348 
   3349 void FullCodeGenerator::EmitStringCharCodeAt(CallRuntime* expr) {
   3350   ZoneList<Expression*>* args = expr->arguments();
   3351   DCHECK(args->length() == 2);
   3352 
   3353   VisitForStackValue(args->at(0));
   3354   VisitForAccumulatorValue(args->at(1));
   3355 
   3356   Register object = x1;
   3357   Register index = x0;
   3358   Register result = x3;
   3359 
   3360   __ Pop(object);
   3361 
   3362   Label need_conversion;
   3363   Label index_out_of_range;
   3364   Label done;
   3365   StringCharCodeAtGenerator generator(object,
   3366                                       index,
   3367                                       result,
   3368                                       &need_conversion,
   3369                                       &need_conversion,
   3370                                       &index_out_of_range,
   3371                                       STRING_INDEX_IS_NUMBER);
   3372   generator.GenerateFast(masm_);
   3373   __ B(&done);
   3374 
   3375   __ Bind(&index_out_of_range);
   3376   // When the index is out of range, the spec requires us to return NaN.
   3377   __ LoadRoot(result, Heap::kNanValueRootIndex);
   3378   __ B(&done);
   3379 
   3380   __ Bind(&need_conversion);
   3381   // Load the undefined value into the result register, which will
   3382   // trigger conversion.
   3383   __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
   3384   __ B(&done);
   3385 
   3386   NopRuntimeCallHelper call_helper;
   3387   generator.GenerateSlow(masm_, call_helper);
   3388 
   3389   __ Bind(&done);
   3390   context()->Plug(result);
   3391 }
   3392 
   3393 
   3394 void FullCodeGenerator::EmitStringCharAt(CallRuntime* expr) {
   3395   ZoneList<Expression*>* args = expr->arguments();
   3396   DCHECK(args->length() == 2);
   3397 
   3398   VisitForStackValue(args->at(0));
   3399   VisitForAccumulatorValue(args->at(1));
   3400 
   3401   Register object = x1;
   3402   Register index = x0;
   3403   Register result = x0;
   3404 
   3405   __ Pop(object);
   3406 
   3407   Label need_conversion;
   3408   Label index_out_of_range;
   3409   Label done;
   3410   StringCharAtGenerator generator(object,
   3411                                   index,
   3412                                   x3,
   3413                                   result,
   3414                                   &need_conversion,
   3415                                   &need_conversion,
   3416                                   &index_out_of_range,
   3417                                   STRING_INDEX_IS_NUMBER);
   3418   generator.GenerateFast(masm_);
   3419   __ B(&done);
   3420 
   3421   __ Bind(&index_out_of_range);
   3422   // When the index is out of range, the spec requires us to return
   3423   // the empty string.
   3424   __ LoadRoot(result, Heap::kempty_stringRootIndex);
   3425   __ B(&done);
   3426 
   3427   __ Bind(&need_conversion);
   3428   // Move smi zero into the result register, which will trigger conversion.
   3429   __ Mov(result, Smi::FromInt(0));
   3430   __ B(&done);
   3431 
   3432   NopRuntimeCallHelper call_helper;
   3433   generator.GenerateSlow(masm_, call_helper);
   3434 
   3435   __ Bind(&done);
   3436   context()->Plug(result);
   3437 }
   3438 
   3439 
   3440 void FullCodeGenerator::EmitStringAdd(CallRuntime* expr) {
   3441   ASM_LOCATION("FullCodeGenerator::EmitStringAdd");
   3442   ZoneList<Expression*>* args = expr->arguments();
   3443   DCHECK_EQ(2, args->length());
   3444 
   3445   VisitForStackValue(args->at(0));
   3446   VisitForAccumulatorValue(args->at(1));
   3447 
   3448   __ Pop(x1);
   3449   StringAddStub stub(isolate(), STRING_ADD_CHECK_BOTH, NOT_TENURED);
   3450   __ CallStub(&stub);
   3451 
   3452   context()->Plug(x0);
   3453 }
   3454 
   3455 
   3456 void FullCodeGenerator::EmitStringCompare(CallRuntime* expr) {
   3457   ZoneList<Expression*>* args = expr->arguments();
   3458   DCHECK_EQ(2, args->length());
   3459   VisitForStackValue(args->at(0));
   3460   VisitForStackValue(args->at(1));
   3461 
   3462   StringCompareStub stub(isolate());
   3463   __ CallStub(&stub);
   3464   context()->Plug(x0);
   3465 }
   3466 
   3467 
   3468 void FullCodeGenerator::EmitCallFunction(CallRuntime* expr) {
   3469   ASM_LOCATION("FullCodeGenerator::EmitCallFunction");
   3470   ZoneList<Expression*>* args = expr->arguments();
   3471   DCHECK(args->length() >= 2);
   3472 
   3473   int arg_count = args->length() - 2;  // 2 ~ receiver and function.
   3474   for (int i = 0; i < arg_count + 1; i++) {
   3475     VisitForStackValue(args->at(i));
   3476   }
   3477   VisitForAccumulatorValue(args->last());  // Function.
   3478 
   3479   Label runtime, done;
   3480   // Check for non-function argument (including proxy).
   3481   __ JumpIfSmi(x0, &runtime);
   3482   __ JumpIfNotObjectType(x0, x1, x1, JS_FUNCTION_TYPE, &runtime);
   3483 
   3484   // InvokeFunction requires the function in x1. Move it in there.
   3485   __ Mov(x1, x0);
   3486   ParameterCount count(arg_count);
   3487   __ InvokeFunction(x1, count, CALL_FUNCTION, NullCallWrapper());
   3488   __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   3489   __ B(&done);
   3490 
   3491   __ Bind(&runtime);
   3492   __ Push(x0);
   3493   __ CallRuntime(Runtime::kCall, args->length());
   3494   __ Bind(&done);
   3495 
   3496   context()->Plug(x0);
   3497 }
   3498 
   3499 
   3500 void FullCodeGenerator::EmitRegExpConstructResult(CallRuntime* expr) {
   3501   RegExpConstructResultStub stub(isolate());
   3502   ZoneList<Expression*>* args = expr->arguments();
   3503   DCHECK(args->length() == 3);
   3504   VisitForStackValue(args->at(0));
   3505   VisitForStackValue(args->at(1));
   3506   VisitForAccumulatorValue(args->at(2));
   3507   __ Pop(x1, x2);
   3508   __ CallStub(&stub);
   3509   context()->Plug(x0);
   3510 }
   3511 
   3512 
   3513 void FullCodeGenerator::EmitGetFromCache(CallRuntime* expr) {
   3514   ZoneList<Expression*>* args = expr->arguments();
   3515   DCHECK_EQ(2, args->length());
   3516   DCHECK_NE(NULL, args->at(0)->AsLiteral());
   3517   int cache_id = Smi::cast(*(args->at(0)->AsLiteral()->value()))->value();
   3518 
   3519   Handle<FixedArray> jsfunction_result_caches(
   3520       isolate()->native_context()->jsfunction_result_caches());
   3521   if (jsfunction_result_caches->length() <= cache_id) {
   3522     __ Abort(kAttemptToUseUndefinedCache);
   3523     __ LoadRoot(x0, Heap::kUndefinedValueRootIndex);
   3524     context()->Plug(x0);
   3525     return;
   3526   }
   3527 
   3528   VisitForAccumulatorValue(args->at(1));
   3529 
   3530   Register key = x0;
   3531   Register cache = x1;
   3532   __ Ldr(cache, GlobalObjectMemOperand());
   3533   __ Ldr(cache, FieldMemOperand(cache, GlobalObject::kNativeContextOffset));
   3534   __ Ldr(cache, ContextMemOperand(cache,
   3535                                   Context::JSFUNCTION_RESULT_CACHES_INDEX));
   3536   __ Ldr(cache,
   3537          FieldMemOperand(cache, FixedArray::OffsetOfElementAt(cache_id)));
   3538 
   3539   Label done;
   3540   __ Ldrsw(x2, UntagSmiFieldMemOperand(cache,
   3541                                        JSFunctionResultCache::kFingerOffset));
   3542   __ Add(x3, cache, FixedArray::kHeaderSize - kHeapObjectTag);
   3543   __ Add(x3, x3, Operand(x2, LSL, kPointerSizeLog2));
   3544 
   3545   // Load the key and data from the cache.
   3546   __ Ldp(x2, x3, MemOperand(x3));
   3547 
   3548   __ Cmp(key, x2);
   3549   __ CmovX(x0, x3, eq);
   3550   __ B(eq, &done);
   3551 
   3552   // Call runtime to perform the lookup.
   3553   __ Push(cache, key);
   3554   __ CallRuntime(Runtime::kGetFromCache, 2);
   3555 
   3556   __ Bind(&done);
   3557   context()->Plug(x0);
   3558 }
   3559 
   3560 
   3561 void FullCodeGenerator::EmitHasCachedArrayIndex(CallRuntime* expr) {
   3562   ZoneList<Expression*>* args = expr->arguments();
   3563   VisitForAccumulatorValue(args->at(0));
   3564 
   3565   Label materialize_true, materialize_false;
   3566   Label* if_true = NULL;
   3567   Label* if_false = NULL;
   3568   Label* fall_through = NULL;
   3569   context()->PrepareTest(&materialize_true, &materialize_false,
   3570                          &if_true, &if_false, &fall_through);
   3571 
   3572   __ Ldr(x10, FieldMemOperand(x0, String::kHashFieldOffset));
   3573   __ Tst(x10, String::kContainsCachedArrayIndexMask);
   3574   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   3575   Split(eq, if_true, if_false, fall_through);
   3576 
   3577   context()->Plug(if_true, if_false);
   3578 }
   3579 
   3580 
   3581 void FullCodeGenerator::EmitGetCachedArrayIndex(CallRuntime* expr) {
   3582   ZoneList<Expression*>* args = expr->arguments();
   3583   DCHECK(args->length() == 1);
   3584   VisitForAccumulatorValue(args->at(0));
   3585 
   3586   __ AssertString(x0);
   3587 
   3588   __ Ldr(x10, FieldMemOperand(x0, String::kHashFieldOffset));
   3589   __ IndexFromHash(x10, x0);
   3590 
   3591   context()->Plug(x0);
   3592 }
   3593 
   3594 
   3595 void FullCodeGenerator::EmitFastOneByteArrayJoin(CallRuntime* expr) {
   3596   ASM_LOCATION("FullCodeGenerator::EmitFastOneByteArrayJoin");
   3597 
   3598   ZoneList<Expression*>* args = expr->arguments();
   3599   DCHECK(args->length() == 2);
   3600   VisitForStackValue(args->at(1));
   3601   VisitForAccumulatorValue(args->at(0));
   3602 
   3603   Register array = x0;
   3604   Register result = x0;
   3605   Register elements = x1;
   3606   Register element = x2;
   3607   Register separator = x3;
   3608   Register array_length = x4;
   3609   Register result_pos = x5;
   3610   Register map = x6;
   3611   Register string_length = x10;
   3612   Register elements_end = x11;
   3613   Register string = x12;
   3614   Register scratch1 = x13;
   3615   Register scratch2 = x14;
   3616   Register scratch3 = x7;
   3617   Register separator_length = x15;
   3618 
   3619   Label bailout, done, one_char_separator, long_separator,
   3620       non_trivial_array, not_size_one_array, loop,
   3621       empty_separator_loop, one_char_separator_loop,
   3622       one_char_separator_loop_entry, long_separator_loop;
   3623 
   3624   // The separator operand is on the stack.
   3625   __ Pop(separator);
   3626 
   3627   // Check that the array is a JSArray.
   3628   __ JumpIfSmi(array, &bailout);
   3629   __ JumpIfNotObjectType(array, map, scratch1, JS_ARRAY_TYPE, &bailout);
   3630 
   3631   // Check that the array has fast elements.
   3632   __ CheckFastElements(map, scratch1, &bailout);
   3633 
   3634   // If the array has length zero, return the empty string.
   3635   // Load and untag the length of the array.
   3636   // It is an unsigned value, so we can skip sign extension.
   3637   // We assume little endianness.
   3638   __ Ldrsw(array_length,
   3639            UntagSmiFieldMemOperand(array, JSArray::kLengthOffset));
   3640   __ Cbnz(array_length, &non_trivial_array);
   3641   __ LoadRoot(result, Heap::kempty_stringRootIndex);
   3642   __ B(&done);
   3643 
   3644   __ Bind(&non_trivial_array);
   3645   // Get the FixedArray containing array's elements.
   3646   __ Ldr(elements, FieldMemOperand(array, JSArray::kElementsOffset));
   3647 
   3648   // Check that all array elements are sequential one-byte strings, and
   3649   // accumulate the sum of their lengths.
   3650   __ Mov(string_length, 0);
   3651   __ Add(element, elements, FixedArray::kHeaderSize - kHeapObjectTag);
   3652   __ Add(elements_end, element, Operand(array_length, LSL, kPointerSizeLog2));
   3653   // Loop condition: while (element < elements_end).
   3654   // Live values in registers:
   3655   //   elements: Fixed array of strings.
   3656   //   array_length: Length of the fixed array of strings (not smi)
   3657   //   separator: Separator string
   3658   //   string_length: Accumulated sum of string lengths (not smi).
   3659   //   element: Current array element.
   3660   //   elements_end: Array end.
   3661   if (FLAG_debug_code) {
   3662     __ Cmp(array_length, 0);
   3663     __ Assert(gt, kNoEmptyArraysHereInEmitFastOneByteArrayJoin);
   3664   }
   3665   __ Bind(&loop);
   3666   __ Ldr(string, MemOperand(element, kPointerSize, PostIndex));
   3667   __ JumpIfSmi(string, &bailout);
   3668   __ Ldr(scratch1, FieldMemOperand(string, HeapObject::kMapOffset));
   3669   __ Ldrb(scratch1, FieldMemOperand(scratch1, Map::kInstanceTypeOffset));
   3670   __ JumpIfInstanceTypeIsNotSequentialOneByte(scratch1, scratch2, &bailout);
   3671   __ Ldrsw(scratch1,
   3672            UntagSmiFieldMemOperand(string, SeqOneByteString::kLengthOffset));
   3673   __ Adds(string_length, string_length, scratch1);
   3674   __ B(vs, &bailout);
   3675   __ Cmp(element, elements_end);
   3676   __ B(lt, &loop);
   3677 
   3678   // If array_length is 1, return elements[0], a string.
   3679   __ Cmp(array_length, 1);
   3680   __ B(ne, &not_size_one_array);
   3681   __ Ldr(result, FieldMemOperand(elements, FixedArray::kHeaderSize));
   3682   __ B(&done);
   3683 
   3684   __ Bind(&not_size_one_array);
   3685 
   3686   // Live values in registers:
   3687   //   separator: Separator string
   3688   //   array_length: Length of the array (not smi).
   3689   //   string_length: Sum of string lengths (not smi).
   3690   //   elements: FixedArray of strings.
   3691 
   3692   // Check that the separator is a flat one-byte string.
   3693   __ JumpIfSmi(separator, &bailout);
   3694   __ Ldr(scratch1, FieldMemOperand(separator, HeapObject::kMapOffset));
   3695   __ Ldrb(scratch1, FieldMemOperand(scratch1, Map::kInstanceTypeOffset));
   3696   __ JumpIfInstanceTypeIsNotSequentialOneByte(scratch1, scratch2, &bailout);
   3697 
   3698   // Add (separator length times array_length) - separator length to the
   3699   // string_length to get the length of the result string.
   3700   // Load the separator length as untagged.
   3701   // We assume little endianness, and that the length is positive.
   3702   __ Ldrsw(separator_length,
   3703            UntagSmiFieldMemOperand(separator,
   3704                                    SeqOneByteString::kLengthOffset));
   3705   __ Sub(string_length, string_length, separator_length);
   3706   __ Umaddl(string_length, array_length.W(), separator_length.W(),
   3707             string_length);
   3708 
   3709   // Get first element in the array.
   3710   __ Add(element, elements, FixedArray::kHeaderSize - kHeapObjectTag);
   3711   // Live values in registers:
   3712   //   element: First array element
   3713   //   separator: Separator string
   3714   //   string_length: Length of result string (not smi)
   3715   //   array_length: Length of the array (not smi).
   3716   __ AllocateOneByteString(result, string_length, scratch1, scratch2, scratch3,
   3717                            &bailout);
   3718 
   3719   // Prepare for looping. Set up elements_end to end of the array. Set
   3720   // result_pos to the position of the result where to write the first
   3721   // character.
   3722   // TODO(all): useless unless AllocateOneByteString trashes the register.
   3723   __ Add(elements_end, element, Operand(array_length, LSL, kPointerSizeLog2));
   3724   __ Add(result_pos, result, SeqOneByteString::kHeaderSize - kHeapObjectTag);
   3725 
   3726   // Check the length of the separator.
   3727   __ Cmp(separator_length, 1);
   3728   __ B(eq, &one_char_separator);
   3729   __ B(gt, &long_separator);
   3730 
   3731   // Empty separator case
   3732   __ Bind(&empty_separator_loop);
   3733   // Live values in registers:
   3734   //   result_pos: the position to which we are currently copying characters.
   3735   //   element: Current array element.
   3736   //   elements_end: Array end.
   3737 
   3738   // Copy next array element to the result.
   3739   __ Ldr(string, MemOperand(element, kPointerSize, PostIndex));
   3740   __ Ldrsw(string_length,
   3741            UntagSmiFieldMemOperand(string, String::kLengthOffset));
   3742   __ Add(string, string, SeqOneByteString::kHeaderSize - kHeapObjectTag);
   3743   __ CopyBytes(result_pos, string, string_length, scratch1);
   3744   __ Cmp(element, elements_end);
   3745   __ B(lt, &empty_separator_loop);  // End while (element < elements_end).
   3746   __ B(&done);
   3747 
   3748   // One-character separator case
   3749   __ Bind(&one_char_separator);
   3750   // Replace separator with its one-byte character value.
   3751   __ Ldrb(separator, FieldMemOperand(separator, SeqOneByteString::kHeaderSize));
   3752   // Jump into the loop after the code that copies the separator, so the first
   3753   // element is not preceded by a separator
   3754   __ B(&one_char_separator_loop_entry);
   3755 
   3756   __ Bind(&one_char_separator_loop);
   3757   // Live values in registers:
   3758   //   result_pos: the position to which we are currently copying characters.
   3759   //   element: Current array element.
   3760   //   elements_end: Array end.
   3761   //   separator: Single separator one-byte char (in lower byte).
   3762 
   3763   // Copy the separator character to the result.
   3764   __ Strb(separator, MemOperand(result_pos, 1, PostIndex));
   3765 
   3766   // Copy next array element to the result.
   3767   __ Bind(&one_char_separator_loop_entry);
   3768   __ Ldr(string, MemOperand(element, kPointerSize, PostIndex));
   3769   __ Ldrsw(string_length,
   3770            UntagSmiFieldMemOperand(string, String::kLengthOffset));
   3771   __ Add(string, string, SeqOneByteString::kHeaderSize - kHeapObjectTag);
   3772   __ CopyBytes(result_pos, string, string_length, scratch1);
   3773   __ Cmp(element, elements_end);
   3774   __ B(lt, &one_char_separator_loop);  // End while (element < elements_end).
   3775   __ B(&done);
   3776 
   3777   // Long separator case (separator is more than one character). Entry is at the
   3778   // label long_separator below.
   3779   __ Bind(&long_separator_loop);
   3780   // Live values in registers:
   3781   //   result_pos: the position to which we are currently copying characters.
   3782   //   element: Current array element.
   3783   //   elements_end: Array end.
   3784   //   separator: Separator string.
   3785 
   3786   // Copy the separator to the result.
   3787   // TODO(all): hoist next two instructions.
   3788   __ Ldrsw(string_length,
   3789            UntagSmiFieldMemOperand(separator, String::kLengthOffset));
   3790   __ Add(string, separator, SeqOneByteString::kHeaderSize - kHeapObjectTag);
   3791   __ CopyBytes(result_pos, string, string_length, scratch1);
   3792 
   3793   __ Bind(&long_separator);
   3794   __ Ldr(string, MemOperand(element, kPointerSize, PostIndex));
   3795   __ Ldrsw(string_length,
   3796            UntagSmiFieldMemOperand(string, String::kLengthOffset));
   3797   __ Add(string, string, SeqOneByteString::kHeaderSize - kHeapObjectTag);
   3798   __ CopyBytes(result_pos, string, string_length, scratch1);
   3799   __ Cmp(element, elements_end);
   3800   __ B(lt, &long_separator_loop);  // End while (element < elements_end).
   3801   __ B(&done);
   3802 
   3803   __ Bind(&bailout);
   3804   // Returning undefined will force slower code to handle it.
   3805   __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
   3806   __ Bind(&done);
   3807   context()->Plug(result);
   3808 }
   3809 
   3810 
   3811 void FullCodeGenerator::EmitDebugIsActive(CallRuntime* expr) {
   3812   DCHECK(expr->arguments()->length() == 0);
   3813   ExternalReference debug_is_active =
   3814       ExternalReference::debug_is_active_address(isolate());
   3815   __ Mov(x10, debug_is_active);
   3816   __ Ldrb(x0, MemOperand(x10));
   3817   __ SmiTag(x0);
   3818   context()->Plug(x0);
   3819 }
   3820 
   3821 
   3822 void FullCodeGenerator::VisitCallRuntime(CallRuntime* expr) {
   3823   if (expr->function() != NULL &&
   3824       expr->function()->intrinsic_type == Runtime::INLINE) {
   3825     Comment cmnt(masm_, "[ InlineRuntimeCall");
   3826     EmitInlineRuntimeCall(expr);
   3827     return;
   3828   }
   3829 
   3830   Comment cmnt(masm_, "[ CallRunTime");
   3831   ZoneList<Expression*>* args = expr->arguments();
   3832   int arg_count = args->length();
   3833 
   3834   if (expr->is_jsruntime()) {
   3835     // Push the builtins object as the receiver.
   3836     __ Ldr(x10, GlobalObjectMemOperand());
   3837     __ Ldr(LoadDescriptor::ReceiverRegister(),
   3838            FieldMemOperand(x10, GlobalObject::kBuiltinsOffset));
   3839     __ Push(LoadDescriptor::ReceiverRegister());
   3840 
   3841     // Load the function from the receiver.
   3842     Handle<String> name = expr->name();
   3843     __ Mov(LoadDescriptor::NameRegister(), Operand(name));
   3844     if (FLAG_vector_ics) {
   3845       __ Mov(VectorLoadICDescriptor::SlotRegister(),
   3846              Smi::FromInt(expr->CallRuntimeFeedbackSlot()));
   3847       CallLoadIC(NOT_CONTEXTUAL);
   3848     } else {
   3849       CallLoadIC(NOT_CONTEXTUAL, expr->CallRuntimeFeedbackId());
   3850     }
   3851 
   3852     // Push the target function under the receiver.
   3853     __ Pop(x10);
   3854     __ Push(x0, x10);
   3855 
   3856     int arg_count = args->length();
   3857     for (int i = 0; i < arg_count; i++) {
   3858       VisitForStackValue(args->at(i));
   3859     }
   3860 
   3861     // Record source position of the IC call.
   3862     SetSourcePosition(expr->position());
   3863     CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
   3864     __ Peek(x1, (arg_count + 1) * kPointerSize);
   3865     __ CallStub(&stub);
   3866 
   3867     // Restore context register.
   3868     __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   3869 
   3870     context()->DropAndPlug(1, x0);
   3871   } else {
   3872     // Push the arguments ("left-to-right").
   3873     for (int i = 0; i < arg_count; i++) {
   3874       VisitForStackValue(args->at(i));
   3875     }
   3876 
   3877     // Call the C runtime function.
   3878     __ CallRuntime(expr->function(), arg_count);
   3879     context()->Plug(x0);
   3880   }
   3881 }
   3882 
   3883 
   3884 void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
   3885   switch (expr->op()) {
   3886     case Token::DELETE: {
   3887       Comment cmnt(masm_, "[ UnaryOperation (DELETE)");
   3888       Property* property = expr->expression()->AsProperty();
   3889       VariableProxy* proxy = expr->expression()->AsVariableProxy();
   3890 
   3891       if (property != NULL) {
   3892         VisitForStackValue(property->obj());
   3893         VisitForStackValue(property->key());
   3894         __ Mov(x10, Smi::FromInt(strict_mode()));
   3895         __ Push(x10);
   3896         __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
   3897         context()->Plug(x0);
   3898       } else if (proxy != NULL) {
   3899         Variable* var = proxy->var();
   3900         // Delete of an unqualified identifier is disallowed in strict mode
   3901         // but "delete this" is allowed.
   3902         DCHECK(strict_mode() == SLOPPY || var->is_this());
   3903         if (var->IsUnallocated()) {
   3904           __ Ldr(x12, GlobalObjectMemOperand());
   3905           __ Mov(x11, Operand(var->name()));
   3906           __ Mov(x10, Smi::FromInt(SLOPPY));
   3907           __ Push(x12, x11, x10);
   3908           __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
   3909           context()->Plug(x0);
   3910         } else if (var->IsStackAllocated() || var->IsContextSlot()) {
   3911           // Result of deleting non-global, non-dynamic variables is false.
   3912           // The subexpression does not have side effects.
   3913           context()->Plug(var->is_this());
   3914         } else {
   3915           // Non-global variable.  Call the runtime to try to delete from the
   3916           // context where the variable was introduced.
   3917           __ Mov(x2, Operand(var->name()));
   3918           __ Push(context_register(), x2);
   3919           __ CallRuntime(Runtime::kDeleteLookupSlot, 2);
   3920           context()->Plug(x0);
   3921         }
   3922       } else {
   3923         // Result of deleting non-property, non-variable reference is true.
   3924         // The subexpression may have side effects.
   3925         VisitForEffect(expr->expression());
   3926         context()->Plug(true);
   3927       }
   3928       break;
   3929       break;
   3930     }
   3931     case Token::VOID: {
   3932       Comment cmnt(masm_, "[ UnaryOperation (VOID)");
   3933       VisitForEffect(expr->expression());
   3934       context()->Plug(Heap::kUndefinedValueRootIndex);
   3935       break;
   3936     }
   3937     case Token::NOT: {
   3938       Comment cmnt(masm_, "[ UnaryOperation (NOT)");
   3939       if (context()->IsEffect()) {
   3940         // Unary NOT has no side effects so it's only necessary to visit the
   3941         // subexpression.  Match the optimizing compiler by not branching.
   3942         VisitForEffect(expr->expression());
   3943       } else if (context()->IsTest()) {
   3944         const TestContext* test = TestContext::cast(context());
   3945         // The labels are swapped for the recursive call.
   3946         VisitForControl(expr->expression(),
   3947                         test->false_label(),
   3948                         test->true_label(),
   3949                         test->fall_through());
   3950         context()->Plug(test->true_label(), test->false_label());
   3951       } else {
   3952         DCHECK(context()->IsAccumulatorValue() || context()->IsStackValue());
   3953         // TODO(jbramley): This could be much more efficient using (for
   3954         // example) the CSEL instruction.
   3955         Label materialize_true, materialize_false, done;
   3956         VisitForControl(expr->expression(),
   3957                         &materialize_false,
   3958                         &materialize_true,
   3959                         &materialize_true);
   3960 
   3961         __ Bind(&materialize_true);
   3962         PrepareForBailoutForId(expr->MaterializeTrueId(), NO_REGISTERS);
   3963         __ LoadRoot(result_register(), Heap::kTrueValueRootIndex);
   3964         __ B(&done);
   3965 
   3966         __ Bind(&materialize_false);
   3967         PrepareForBailoutForId(expr->MaterializeFalseId(), NO_REGISTERS);
   3968         __ LoadRoot(result_register(), Heap::kFalseValueRootIndex);
   3969         __ B(&done);
   3970 
   3971         __ Bind(&done);
   3972         if (context()->IsStackValue()) {
   3973           __ Push(result_register());
   3974         }
   3975       }
   3976       break;
   3977     }
   3978     case Token::TYPEOF: {
   3979       Comment cmnt(masm_, "[ UnaryOperation (TYPEOF)");
   3980       {
   3981         StackValueContext context(this);
   3982         VisitForTypeofValue(expr->expression());
   3983       }
   3984       __ CallRuntime(Runtime::kTypeof, 1);
   3985       context()->Plug(x0);
   3986       break;
   3987     }
   3988     default:
   3989       UNREACHABLE();
   3990   }
   3991 }
   3992 
   3993 
   3994 void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
   3995   DCHECK(expr->expression()->IsValidReferenceExpression());
   3996 
   3997   Comment cmnt(masm_, "[ CountOperation");
   3998   SetSourcePosition(expr->position());
   3999 
   4000   // Expression can only be a property, a global or a (parameter or local)
   4001   // slot.
   4002   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   4003   LhsKind assign_type = VARIABLE;
   4004   Property* prop = expr->expression()->AsProperty();
   4005   // In case of a property we use the uninitialized expression context
   4006   // of the key to detect a named property.
   4007   if (prop != NULL) {
   4008     assign_type =
   4009         (prop->key()->IsPropertyName()) ? NAMED_PROPERTY : KEYED_PROPERTY;
   4010   }
   4011 
   4012   // Evaluate expression and get value.
   4013   if (assign_type == VARIABLE) {
   4014     DCHECK(expr->expression()->AsVariableProxy()->var() != NULL);
   4015     AccumulatorValueContext context(this);
   4016     EmitVariableLoad(expr->expression()->AsVariableProxy());
   4017   } else {
   4018     // Reserve space for result of postfix operation.
   4019     if (expr->is_postfix() && !context()->IsEffect()) {
   4020       __ Push(xzr);
   4021     }
   4022     if (assign_type == NAMED_PROPERTY) {
   4023       // Put the object both on the stack and in the register.
   4024       VisitForStackValue(prop->obj());
   4025       __ Peek(LoadDescriptor::ReceiverRegister(), 0);
   4026       EmitNamedPropertyLoad(prop);
   4027     } else {
   4028       // KEYED_PROPERTY
   4029       VisitForStackValue(prop->obj());
   4030       VisitForStackValue(prop->key());
   4031       __ Peek(LoadDescriptor::ReceiverRegister(), 1 * kPointerSize);
   4032       __ Peek(LoadDescriptor::NameRegister(), 0);
   4033       EmitKeyedPropertyLoad(prop);
   4034     }
   4035   }
   4036 
   4037   // We need a second deoptimization point after loading the value
   4038   // in case evaluating the property load my have a side effect.
   4039   if (assign_type == VARIABLE) {
   4040     PrepareForBailout(expr->expression(), TOS_REG);
   4041   } else {
   4042     PrepareForBailoutForId(prop->LoadId(), TOS_REG);
   4043   }
   4044 
   4045   // Inline smi case if we are in a loop.
   4046   Label stub_call, done;
   4047   JumpPatchSite patch_site(masm_);
   4048 
   4049   int count_value = expr->op() == Token::INC ? 1 : -1;
   4050   if (ShouldInlineSmiCase(expr->op())) {
   4051     Label slow;
   4052     patch_site.EmitJumpIfNotSmi(x0, &slow);
   4053 
   4054     // Save result for postfix expressions.
   4055     if (expr->is_postfix()) {
   4056       if (!context()->IsEffect()) {
   4057         // Save the result on the stack. If we have a named or keyed property we
   4058         // store the result under the receiver that is currently on top of the
   4059         // stack.
   4060         switch (assign_type) {
   4061           case VARIABLE:
   4062             __ Push(x0);
   4063             break;
   4064           case NAMED_PROPERTY:
   4065             __ Poke(x0, kPointerSize);
   4066             break;
   4067           case KEYED_PROPERTY:
   4068             __ Poke(x0, kPointerSize * 2);
   4069             break;
   4070         }
   4071       }
   4072     }
   4073 
   4074     __ Adds(x0, x0, Smi::FromInt(count_value));
   4075     __ B(vc, &done);
   4076     // Call stub. Undo operation first.
   4077     __ Sub(x0, x0, Smi::FromInt(count_value));
   4078     __ B(&stub_call);
   4079     __ Bind(&slow);
   4080   }
   4081   ToNumberStub convert_stub(isolate());
   4082   __ CallStub(&convert_stub);
   4083 
   4084   // Save result for postfix expressions.
   4085   if (expr->is_postfix()) {
   4086     if (!context()->IsEffect()) {
   4087       // Save the result on the stack. If we have a named or keyed property
   4088       // we store the result under the receiver that is currently on top
   4089       // of the stack.
   4090       switch (assign_type) {
   4091         case VARIABLE:
   4092           __ Push(x0);
   4093           break;
   4094         case NAMED_PROPERTY:
   4095           __ Poke(x0, kXRegSize);
   4096           break;
   4097         case KEYED_PROPERTY:
   4098           __ Poke(x0, 2 * kXRegSize);
   4099           break;
   4100       }
   4101     }
   4102   }
   4103 
   4104   __ Bind(&stub_call);
   4105   __ Mov(x1, x0);
   4106   __ Mov(x0, Smi::FromInt(count_value));
   4107 
   4108   // Record position before stub call.
   4109   SetSourcePosition(expr->position());
   4110 
   4111   {
   4112     Assembler::BlockPoolsScope scope(masm_);
   4113     Handle<Code> code =
   4114         CodeFactory::BinaryOpIC(isolate(), Token::ADD, NO_OVERWRITE).code();
   4115     CallIC(code, expr->CountBinOpFeedbackId());
   4116     patch_site.EmitPatchInfo();
   4117   }
   4118   __ Bind(&done);
   4119 
   4120   // Store the value returned in x0.
   4121   switch (assign_type) {
   4122     case VARIABLE:
   4123       if (expr->is_postfix()) {
   4124         { EffectContext context(this);
   4125           EmitVariableAssignment(expr->expression()->AsVariableProxy()->var(),
   4126                                  Token::ASSIGN);
   4127           PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   4128           context.Plug(x0);
   4129         }
   4130         // For all contexts except EffectConstant We have the result on
   4131         // top of the stack.
   4132         if (!context()->IsEffect()) {
   4133           context()->PlugTOS();
   4134         }
   4135       } else {
   4136         EmitVariableAssignment(expr->expression()->AsVariableProxy()->var(),
   4137                                Token::ASSIGN);
   4138         PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   4139         context()->Plug(x0);
   4140       }
   4141       break;
   4142     case NAMED_PROPERTY: {
   4143       __ Mov(StoreDescriptor::NameRegister(),
   4144              Operand(prop->key()->AsLiteral()->value()));
   4145       __ Pop(StoreDescriptor::ReceiverRegister());
   4146       CallStoreIC(expr->CountStoreFeedbackId());
   4147       PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   4148       if (expr->is_postfix()) {
   4149         if (!context()->IsEffect()) {
   4150           context()->PlugTOS();
   4151         }
   4152       } else {
   4153         context()->Plug(x0);
   4154       }
   4155       break;
   4156     }
   4157     case KEYED_PROPERTY: {
   4158       __ Pop(StoreDescriptor::NameRegister());
   4159       __ Pop(StoreDescriptor::ReceiverRegister());
   4160       Handle<Code> ic =
   4161           CodeFactory::KeyedStoreIC(isolate(), strict_mode()).code();
   4162       CallIC(ic, expr->CountStoreFeedbackId());
   4163       PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   4164       if (expr->is_postfix()) {
   4165         if (!context()->IsEffect()) {
   4166           context()->PlugTOS();
   4167         }
   4168       } else {
   4169         context()->Plug(x0);
   4170       }
   4171       break;
   4172     }
   4173   }
   4174 }
   4175 
   4176 
   4177 void FullCodeGenerator::VisitForTypeofValue(Expression* expr) {
   4178   DCHECK(!context()->IsEffect());
   4179   DCHECK(!context()->IsTest());
   4180   VariableProxy* proxy = expr->AsVariableProxy();
   4181   if (proxy != NULL && proxy->var()->IsUnallocated()) {
   4182     Comment cmnt(masm_, "Global variable");
   4183     __ Ldr(LoadDescriptor::ReceiverRegister(), GlobalObjectMemOperand());
   4184     __ Mov(LoadDescriptor::NameRegister(), Operand(proxy->name()));
   4185     if (FLAG_vector_ics) {
   4186       __ Mov(VectorLoadICDescriptor::SlotRegister(),
   4187              Smi::FromInt(proxy->VariableFeedbackSlot()));
   4188     }
   4189     // Use a regular load, not a contextual load, to avoid a reference
   4190     // error.
   4191     CallLoadIC(NOT_CONTEXTUAL);
   4192     PrepareForBailout(expr, TOS_REG);
   4193     context()->Plug(x0);
   4194   } else if (proxy != NULL && proxy->var()->IsLookupSlot()) {
   4195     Label done, slow;
   4196 
   4197     // Generate code for loading from variables potentially shadowed
   4198     // by eval-introduced variables.
   4199     EmitDynamicLookupFastCase(proxy, INSIDE_TYPEOF, &slow, &done);
   4200 
   4201     __ Bind(&slow);
   4202     __ Mov(x0, Operand(proxy->name()));
   4203     __ Push(cp, x0);
   4204     __ CallRuntime(Runtime::kLoadLookupSlotNoReferenceError, 2);
   4205     PrepareForBailout(expr, TOS_REG);
   4206     __ Bind(&done);
   4207 
   4208     context()->Plug(x0);
   4209   } else {
   4210     // This expression cannot throw a reference error at the top level.
   4211     VisitInDuplicateContext(expr);
   4212   }
   4213 }
   4214 
   4215 
   4216 void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
   4217                                                  Expression* sub_expr,
   4218                                                  Handle<String> check) {
   4219   ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareTypeof");
   4220   Comment cmnt(masm_, "[ EmitLiteralCompareTypeof");
   4221   Label materialize_true, materialize_false;
   4222   Label* if_true = NULL;
   4223   Label* if_false = NULL;
   4224   Label* fall_through = NULL;
   4225   context()->PrepareTest(&materialize_true, &materialize_false,
   4226                          &if_true, &if_false, &fall_through);
   4227 
   4228   { AccumulatorValueContext context(this);
   4229     VisitForTypeofValue(sub_expr);
   4230   }
   4231   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   4232 
   4233   Factory* factory = isolate()->factory();
   4234   if (String::Equals(check, factory->number_string())) {
   4235     ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareTypeof number_string");
   4236     __ JumpIfSmi(x0, if_true);
   4237     __ Ldr(x0, FieldMemOperand(x0, HeapObject::kMapOffset));
   4238     __ CompareRoot(x0, Heap::kHeapNumberMapRootIndex);
   4239     Split(eq, if_true, if_false, fall_through);
   4240   } else if (String::Equals(check, factory->string_string())) {
   4241     ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareTypeof string_string");
   4242     __ JumpIfSmi(x0, if_false);
   4243     // Check for undetectable objects => false.
   4244     __ JumpIfObjectType(x0, x0, x1, FIRST_NONSTRING_TYPE, if_false, ge);
   4245     __ Ldrb(x1, FieldMemOperand(x0, Map::kBitFieldOffset));
   4246     __ TestAndSplit(x1, 1 << Map::kIsUndetectable, if_true, if_false,
   4247                     fall_through);
   4248   } else if (String::Equals(check, factory->symbol_string())) {
   4249     ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareTypeof symbol_string");
   4250     __ JumpIfSmi(x0, if_false);
   4251     __ CompareObjectType(x0, x0, x1, SYMBOL_TYPE);
   4252     Split(eq, if_true, if_false, fall_through);
   4253   } else if (String::Equals(check, factory->boolean_string())) {
   4254     ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareTypeof boolean_string");
   4255     __ JumpIfRoot(x0, Heap::kTrueValueRootIndex, if_true);
   4256     __ CompareRoot(x0, Heap::kFalseValueRootIndex);
   4257     Split(eq, if_true, if_false, fall_through);
   4258   } else if (String::Equals(check, factory->undefined_string())) {
   4259     ASM_LOCATION(
   4260         "FullCodeGenerator::EmitLiteralCompareTypeof undefined_string");
   4261     __ JumpIfRoot(x0, Heap::kUndefinedValueRootIndex, if_true);
   4262     __ JumpIfSmi(x0, if_false);
   4263     // Check for undetectable objects => true.
   4264     __ Ldr(x0, FieldMemOperand(x0, HeapObject::kMapOffset));
   4265     __ Ldrb(x1, FieldMemOperand(x0, Map::kBitFieldOffset));
   4266     __ TestAndSplit(x1, 1 << Map::kIsUndetectable, if_false, if_true,
   4267                     fall_through);
   4268   } else if (String::Equals(check, factory->function_string())) {
   4269     ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareTypeof function_string");
   4270     __ JumpIfSmi(x0, if_false);
   4271     STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
   4272     __ JumpIfObjectType(x0, x10, x11, JS_FUNCTION_TYPE, if_true);
   4273     __ CompareAndSplit(x11, JS_FUNCTION_PROXY_TYPE, eq, if_true, if_false,
   4274                        fall_through);
   4275 
   4276   } else if (String::Equals(check, factory->object_string())) {
   4277     ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareTypeof object_string");
   4278     __ JumpIfSmi(x0, if_false);
   4279     __ JumpIfRoot(x0, Heap::kNullValueRootIndex, if_true);
   4280     // Check for JS objects => true.
   4281     Register map = x10;
   4282     __ JumpIfObjectType(x0, map, x11, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE,
   4283                         if_false, lt);
   4284     __ CompareInstanceType(map, x11, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
   4285     __ B(gt, if_false);
   4286     // Check for undetectable objects => false.
   4287     __ Ldrb(x10, FieldMemOperand(map, Map::kBitFieldOffset));
   4288 
   4289     __ TestAndSplit(x10, 1 << Map::kIsUndetectable, if_true, if_false,
   4290                     fall_through);
   4291 
   4292   } else {
   4293     ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareTypeof other");
   4294     if (if_false != fall_through) __ B(if_false);
   4295   }
   4296   context()->Plug(if_true, if_false);
   4297 }
   4298 
   4299 
   4300 void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   4301   Comment cmnt(masm_, "[ CompareOperation");
   4302   SetSourcePosition(expr->position());
   4303 
   4304   // Try to generate an optimized comparison with a literal value.
   4305   // TODO(jbramley): This only checks common values like NaN or undefined.
   4306   // Should it also handle ARM64 immediate operands?
   4307   if (TryLiteralCompare(expr)) {
   4308     return;
   4309   }
   4310 
   4311   // Assign labels according to context()->PrepareTest.
   4312   Label materialize_true;
   4313   Label materialize_false;
   4314   Label* if_true = NULL;
   4315   Label* if_false = NULL;
   4316   Label* fall_through = NULL;
   4317   context()->PrepareTest(&materialize_true, &materialize_false,
   4318                          &if_true, &if_false, &fall_through);
   4319 
   4320   Token::Value op = expr->op();
   4321   VisitForStackValue(expr->left());
   4322   switch (op) {
   4323     case Token::IN:
   4324       VisitForStackValue(expr->right());
   4325       __ InvokeBuiltin(Builtins::IN, CALL_FUNCTION);
   4326       PrepareForBailoutBeforeSplit(expr, false, NULL, NULL);
   4327       __ CompareRoot(x0, Heap::kTrueValueRootIndex);
   4328       Split(eq, if_true, if_false, fall_through);
   4329       break;
   4330 
   4331     case Token::INSTANCEOF: {
   4332       VisitForStackValue(expr->right());
   4333       InstanceofStub stub(isolate(), InstanceofStub::kNoFlags);
   4334       __ CallStub(&stub);
   4335       PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   4336       // The stub returns 0 for true.
   4337       __ CompareAndSplit(x0, 0, eq, if_true, if_false, fall_through);
   4338       break;
   4339     }
   4340 
   4341     default: {
   4342       VisitForAccumulatorValue(expr->right());
   4343       Condition cond = CompareIC::ComputeCondition(op);
   4344 
   4345       // Pop the stack value.
   4346       __ Pop(x1);
   4347 
   4348       JumpPatchSite patch_site(masm_);
   4349       if (ShouldInlineSmiCase(op)) {
   4350         Label slow_case;
   4351         patch_site.EmitJumpIfEitherNotSmi(x0, x1, &slow_case);
   4352         __ Cmp(x1, x0);
   4353         Split(cond, if_true, if_false, NULL);
   4354         __ Bind(&slow_case);
   4355       }
   4356 
   4357       // Record position and call the compare IC.
   4358       SetSourcePosition(expr->position());
   4359       Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
   4360       CallIC(ic, expr->CompareOperationFeedbackId());
   4361       patch_site.EmitPatchInfo();
   4362       PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   4363       __ CompareAndSplit(x0, 0, cond, if_true, if_false, fall_through);
   4364     }
   4365   }
   4366 
   4367   // Convert the result of the comparison into one expected for this
   4368   // expression's context.
   4369   context()->Plug(if_true, if_false);
   4370 }
   4371 
   4372 
   4373 void FullCodeGenerator::EmitLiteralCompareNil(CompareOperation* expr,
   4374                                               Expression* sub_expr,
   4375                                               NilValue nil) {
   4376   ASM_LOCATION("FullCodeGenerator::EmitLiteralCompareNil");
   4377   Label materialize_true, materialize_false;
   4378   Label* if_true = NULL;
   4379   Label* if_false = NULL;
   4380   Label* fall_through = NULL;
   4381   context()->PrepareTest(&materialize_true, &materialize_false,
   4382                          &if_true, &if_false, &fall_through);
   4383 
   4384   VisitForAccumulatorValue(sub_expr);
   4385   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
   4386 
   4387   if (expr->op() == Token::EQ_STRICT) {
   4388     Heap::RootListIndex nil_value = nil == kNullValue ?
   4389         Heap::kNullValueRootIndex :
   4390         Heap::kUndefinedValueRootIndex;
   4391     __ CompareRoot(x0, nil_value);
   4392     Split(eq, if_true, if_false, fall_through);
   4393   } else {
   4394     Handle<Code> ic = CompareNilICStub::GetUninitialized(isolate(), nil);
   4395     CallIC(ic, expr->CompareOperationFeedbackId());
   4396     __ CompareAndSplit(x0, 0, ne, if_true, if_false, fall_through);
   4397   }
   4398 
   4399   context()->Plug(if_true, if_false);
   4400 }
   4401 
   4402 
   4403 void FullCodeGenerator::VisitThisFunction(ThisFunction* expr) {
   4404   __ Ldr(x0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   4405   context()->Plug(x0);
   4406 }
   4407 
   4408 
   4409 void FullCodeGenerator::VisitYield(Yield* expr) {
   4410   Comment cmnt(masm_, "[ Yield");
   4411   // Evaluate yielded value first; the initial iterator definition depends on
   4412   // this. It stays on the stack while we update the iterator.
   4413   VisitForStackValue(expr->expression());
   4414 
   4415   // TODO(jbramley): Tidy this up once the merge is done, using named registers
   4416   // and suchlike. The implementation changes a little by bleeding_edge so I
   4417   // don't want to spend too much time on it now.
   4418 
   4419   switch (expr->yield_kind()) {
   4420     case Yield::kSuspend:
   4421       // Pop value from top-of-stack slot; box result into result register.
   4422       EmitCreateIteratorResult(false);
   4423       __ Push(result_register());
   4424       // Fall through.
   4425     case Yield::kInitial: {
   4426       Label suspend, continuation, post_runtime, resume;
   4427 
   4428       __ B(&suspend);
   4429 
   4430       // TODO(jbramley): This label is bound here because the following code
   4431       // looks at its pos(). Is it possible to do something more efficient here,
   4432       // perhaps using Adr?
   4433       __ Bind(&continuation);
   4434       __ B(&resume);
   4435 
   4436       __ Bind(&suspend);
   4437       VisitForAccumulatorValue(expr->generator_object());
   4438       DCHECK((continuation.pos() > 0) && Smi::IsValid(continuation.pos()));
   4439       __ Mov(x1, Smi::FromInt(continuation.pos()));
   4440       __ Str(x1, FieldMemOperand(x0, JSGeneratorObject::kContinuationOffset));
   4441       __ Str(cp, FieldMemOperand(x0, JSGeneratorObject::kContextOffset));
   4442       __ Mov(x1, cp);
   4443       __ RecordWriteField(x0, JSGeneratorObject::kContextOffset, x1, x2,
   4444                           kLRHasBeenSaved, kDontSaveFPRegs);
   4445       __ Add(x1, fp, StandardFrameConstants::kExpressionsOffset);
   4446       __ Cmp(__ StackPointer(), x1);
   4447       __ B(eq, &post_runtime);
   4448       __ Push(x0);  // generator object
   4449       __ CallRuntime(Runtime::kSuspendJSGeneratorObject, 1);
   4450       __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   4451       __ Bind(&post_runtime);
   4452       __ Pop(result_register());
   4453       EmitReturnSequence();
   4454 
   4455       __ Bind(&resume);
   4456       context()->Plug(result_register());
   4457       break;
   4458     }
   4459 
   4460     case Yield::kFinal: {
   4461       VisitForAccumulatorValue(expr->generator_object());
   4462       __ Mov(x1, Smi::FromInt(JSGeneratorObject::kGeneratorClosed));
   4463       __ Str(x1, FieldMemOperand(result_register(),
   4464                                  JSGeneratorObject::kContinuationOffset));
   4465       // Pop value from top-of-stack slot, box result into result register.
   4466       EmitCreateIteratorResult(true);
   4467       EmitUnwindBeforeReturn();
   4468       EmitReturnSequence();
   4469       break;
   4470     }
   4471 
   4472     case Yield::kDelegating: {
   4473       VisitForStackValue(expr->generator_object());
   4474 
   4475       // Initial stack layout is as follows:
   4476       // [sp + 1 * kPointerSize] iter
   4477       // [sp + 0 * kPointerSize] g
   4478 
   4479       Label l_catch, l_try, l_suspend, l_continuation, l_resume;
   4480       Label l_next, l_call, l_loop;
   4481       Register load_receiver = LoadDescriptor::ReceiverRegister();
   4482       Register load_name = LoadDescriptor::NameRegister();
   4483 
   4484       // Initial send value is undefined.
   4485       __ LoadRoot(x0, Heap::kUndefinedValueRootIndex);
   4486       __ B(&l_next);
   4487 
   4488       // catch (e) { receiver = iter; f = 'throw'; arg = e; goto l_call; }
   4489       __ Bind(&l_catch);
   4490       handler_table()->set(expr->index(), Smi::FromInt(l_catch.pos()));
   4491       __ LoadRoot(load_name, Heap::kthrow_stringRootIndex);  // "throw"
   4492       __ Peek(x3, 1 * kPointerSize);                         // iter
   4493       __ Push(load_name, x3, x0);                       // "throw", iter, except
   4494       __ B(&l_call);
   4495 
   4496       // try { received = %yield result }
   4497       // Shuffle the received result above a try handler and yield it without
   4498       // re-boxing.
   4499       __ Bind(&l_try);
   4500       __ Pop(x0);                                        // result
   4501       __ PushTryHandler(StackHandler::CATCH, expr->index());
   4502       const int handler_size = StackHandlerConstants::kSize;
   4503       __ Push(x0);                                       // result
   4504       __ B(&l_suspend);
   4505 
   4506       // TODO(jbramley): This label is bound here because the following code
   4507       // looks at its pos(). Is it possible to do something more efficient here,
   4508       // perhaps using Adr?
   4509       __ Bind(&l_continuation);
   4510       __ B(&l_resume);
   4511 
   4512       __ Bind(&l_suspend);
   4513       const int generator_object_depth = kPointerSize + handler_size;
   4514       __ Peek(x0, generator_object_depth);
   4515       __ Push(x0);                                       // g
   4516       DCHECK((l_continuation.pos() > 0) && Smi::IsValid(l_continuation.pos()));
   4517       __ Mov(x1, Smi::FromInt(l_continuation.pos()));
   4518       __ Str(x1, FieldMemOperand(x0, JSGeneratorObject::kContinuationOffset));
   4519       __ Str(cp, FieldMemOperand(x0, JSGeneratorObject::kContextOffset));
   4520       __ Mov(x1, cp);
   4521       __ RecordWriteField(x0, JSGeneratorObject::kContextOffset, x1, x2,
   4522                           kLRHasBeenSaved, kDontSaveFPRegs);
   4523       __ CallRuntime(Runtime::kSuspendJSGeneratorObject, 1);
   4524       __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   4525       __ Pop(x0);                                        // result
   4526       EmitReturnSequence();
   4527       __ Bind(&l_resume);                                // received in x0
   4528       __ PopTryHandler();
   4529 
   4530       // receiver = iter; f = 'next'; arg = received;
   4531       __ Bind(&l_next);
   4532 
   4533       __ LoadRoot(load_name, Heap::knext_stringRootIndex);  // "next"
   4534       __ Peek(x3, 1 * kPointerSize);                        // iter
   4535       __ Push(load_name, x3, x0);                      // "next", iter, received
   4536 
   4537       // result = receiver[f](arg);
   4538       __ Bind(&l_call);
   4539       __ Peek(load_receiver, 1 * kPointerSize);
   4540       __ Peek(load_name, 2 * kPointerSize);
   4541       if (FLAG_vector_ics) {
   4542         __ Mov(VectorLoadICDescriptor::SlotRegister(),
   4543                Smi::FromInt(expr->KeyedLoadFeedbackSlot()));
   4544       }
   4545       Handle<Code> ic = CodeFactory::KeyedLoadIC(isolate()).code();
   4546       CallIC(ic, TypeFeedbackId::None());
   4547       __ Mov(x1, x0);
   4548       __ Poke(x1, 2 * kPointerSize);
   4549       CallFunctionStub stub(isolate(), 1, CALL_AS_METHOD);
   4550       __ CallStub(&stub);
   4551 
   4552       __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   4553       __ Drop(1);  // The function is still on the stack; drop it.
   4554 
   4555       // if (!result.done) goto l_try;
   4556       __ Bind(&l_loop);
   4557       __ Move(load_receiver, x0);
   4558 
   4559       __ Push(load_receiver);                               // save result
   4560       __ LoadRoot(load_name, Heap::kdone_stringRootIndex);  // "done"
   4561       if (FLAG_vector_ics) {
   4562         __ Mov(VectorLoadICDescriptor::SlotRegister(),
   4563                Smi::FromInt(expr->DoneFeedbackSlot()));
   4564       }
   4565       CallLoadIC(NOT_CONTEXTUAL);                           // x0=result.done
   4566       // The ToBooleanStub argument (result.done) is in x0.
   4567       Handle<Code> bool_ic = ToBooleanStub::GetUninitialized(isolate());
   4568       CallIC(bool_ic);
   4569       __ Cbz(x0, &l_try);
   4570 
   4571       // result.value
   4572       __ Pop(load_receiver);                                 // result
   4573       __ LoadRoot(load_name, Heap::kvalue_stringRootIndex);  // "value"
   4574       if (FLAG_vector_ics) {
   4575         __ Mov(VectorLoadICDescriptor::SlotRegister(),
   4576                Smi::FromInt(expr->ValueFeedbackSlot()));
   4577       }
   4578       CallLoadIC(NOT_CONTEXTUAL);                            // x0=result.value
   4579       context()->DropAndPlug(2, x0);                         // drop iter and g
   4580       break;
   4581     }
   4582   }
   4583 }
   4584 
   4585 
   4586 void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
   4587     Expression *value,
   4588     JSGeneratorObject::ResumeMode resume_mode) {
   4589   ASM_LOCATION("FullCodeGenerator::EmitGeneratorResume");
   4590   Register value_reg = x0;
   4591   Register generator_object = x1;
   4592   Register the_hole = x2;
   4593   Register operand_stack_size = w3;
   4594   Register function = x4;
   4595 
   4596   // The value stays in x0, and is ultimately read by the resumed generator, as
   4597   // if CallRuntime(Runtime::kSuspendJSGeneratorObject) returned it. Or it
   4598   // is read to throw the value when the resumed generator is already closed. r1
   4599   // will hold the generator object until the activation has been resumed.
   4600   VisitForStackValue(generator);
   4601   VisitForAccumulatorValue(value);
   4602   __ Pop(generator_object);
   4603 
   4604   // Check generator state.
   4605   Label wrong_state, closed_state, done;
   4606   __ Ldr(x10, FieldMemOperand(generator_object,
   4607                               JSGeneratorObject::kContinuationOffset));
   4608   STATIC_ASSERT(JSGeneratorObject::kGeneratorExecuting < 0);
   4609   STATIC_ASSERT(JSGeneratorObject::kGeneratorClosed == 0);
   4610   __ CompareAndBranch(x10, Smi::FromInt(0), eq, &closed_state);
   4611   __ CompareAndBranch(x10, Smi::FromInt(0), lt, &wrong_state);
   4612 
   4613   // Load suspended function and context.
   4614   __ Ldr(cp, FieldMemOperand(generator_object,
   4615                              JSGeneratorObject::kContextOffset));
   4616   __ Ldr(function, FieldMemOperand(generator_object,
   4617                                    JSGeneratorObject::kFunctionOffset));
   4618 
   4619   // Load receiver and store as the first argument.
   4620   __ Ldr(x10, FieldMemOperand(generator_object,
   4621                               JSGeneratorObject::kReceiverOffset));
   4622   __ Push(x10);
   4623 
   4624   // Push holes for the rest of the arguments to the generator function.
   4625   __ Ldr(x10, FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
   4626 
   4627   // The number of arguments is stored as an int32_t, and -1 is a marker
   4628   // (SharedFunctionInfo::kDontAdaptArgumentsSentinel), so we need sign
   4629   // extension to correctly handle it. However, in this case, we operate on
   4630   // 32-bit W registers, so extension isn't required.
   4631   __ Ldr(w10, FieldMemOperand(x10,
   4632                               SharedFunctionInfo::kFormalParameterCountOffset));
   4633   __ LoadRoot(the_hole, Heap::kTheHoleValueRootIndex);
   4634   __ PushMultipleTimes(the_hole, w10);
   4635 
   4636   // Enter a new JavaScript frame, and initialize its slots as they were when
   4637   // the generator was suspended.
   4638   Label resume_frame;
   4639   __ Bl(&resume_frame);
   4640   __ B(&done);
   4641 
   4642   __ Bind(&resume_frame);
   4643   __ Push(lr,           // Return address.
   4644           fp,           // Caller's frame pointer.
   4645           cp,           // Callee's context.
   4646           function);    // Callee's JS Function.
   4647   __ Add(fp, __ StackPointer(), kPointerSize * 2);
   4648 
   4649   // Load and untag the operand stack size.
   4650   __ Ldr(x10, FieldMemOperand(generator_object,
   4651                               JSGeneratorObject::kOperandStackOffset));
   4652   __ Ldr(operand_stack_size,
   4653          UntagSmiFieldMemOperand(x10, FixedArray::kLengthOffset));
   4654 
   4655   // If we are sending a value and there is no operand stack, we can jump back
   4656   // in directly.
   4657   if (resume_mode == JSGeneratorObject::NEXT) {
   4658     Label slow_resume;
   4659     __ Cbnz(operand_stack_size, &slow_resume);
   4660     __ Ldr(x10, FieldMemOperand(function, JSFunction::kCodeEntryOffset));
   4661     __ Ldrsw(x11,
   4662              UntagSmiFieldMemOperand(generator_object,
   4663                                      JSGeneratorObject::kContinuationOffset));
   4664     __ Add(x10, x10, x11);
   4665     __ Mov(x12, Smi::FromInt(JSGeneratorObject::kGeneratorExecuting));
   4666     __ Str(x12, FieldMemOperand(generator_object,
   4667                                 JSGeneratorObject::kContinuationOffset));
   4668     __ Br(x10);
   4669 
   4670     __ Bind(&slow_resume);
   4671   }
   4672 
   4673   // Otherwise, we push holes for the operand stack and call the runtime to fix
   4674   // up the stack and the handlers.
   4675   __ PushMultipleTimes(the_hole, operand_stack_size);
   4676 
   4677   __ Mov(x10, Smi::FromInt(resume_mode));
   4678   __ Push(generator_object, result_register(), x10);
   4679   __ CallRuntime(Runtime::kResumeJSGeneratorObject, 3);
   4680   // Not reached: the runtime call returns elsewhere.
   4681   __ Unreachable();
   4682 
   4683   // Reach here when generator is closed.
   4684   __ Bind(&closed_state);
   4685   if (resume_mode == JSGeneratorObject::NEXT) {
   4686     // Return completed iterator result when generator is closed.
   4687     __ LoadRoot(x10, Heap::kUndefinedValueRootIndex);
   4688     __ Push(x10);
   4689     // Pop value from top-of-stack slot; box result into result register.
   4690     EmitCreateIteratorResult(true);
   4691   } else {
   4692     // Throw the provided value.
   4693     __ Push(value_reg);
   4694     __ CallRuntime(Runtime::kThrow, 1);
   4695   }
   4696   __ B(&done);
   4697 
   4698   // Throw error if we attempt to operate on a running generator.
   4699   __ Bind(&wrong_state);
   4700   __ Push(generator_object);
   4701   __ CallRuntime(Runtime::kThrowGeneratorStateError, 1);
   4702 
   4703   __ Bind(&done);
   4704   context()->Plug(result_register());
   4705 }
   4706 
   4707 
   4708 void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
   4709   Label gc_required;
   4710   Label allocated;
   4711 
   4712   Handle<Map> map(isolate()->native_context()->iterator_result_map());
   4713 
   4714   // Allocate and populate an object with this form: { value: VAL, done: DONE }
   4715 
   4716   Register result = x0;
   4717   __ Allocate(map->instance_size(), result, x10, x11, &gc_required, TAG_OBJECT);
   4718   __ B(&allocated);
   4719 
   4720   __ Bind(&gc_required);
   4721   __ Push(Smi::FromInt(map->instance_size()));
   4722   __ CallRuntime(Runtime::kAllocateInNewSpace, 1);
   4723   __ Ldr(context_register(),
   4724          MemOperand(fp, StandardFrameConstants::kContextOffset));
   4725 
   4726   __ Bind(&allocated);
   4727   Register map_reg = x1;
   4728   Register result_value = x2;
   4729   Register boolean_done = x3;
   4730   Register empty_fixed_array = x4;
   4731   Register untagged_result = x5;
   4732   __ Mov(map_reg, Operand(map));
   4733   __ Pop(result_value);
   4734   __ Mov(boolean_done, Operand(isolate()->factory()->ToBoolean(done)));
   4735   __ Mov(empty_fixed_array, Operand(isolate()->factory()->empty_fixed_array()));
   4736   DCHECK_EQ(map->instance_size(), 5 * kPointerSize);
   4737   STATIC_ASSERT(JSObject::kPropertiesOffset + kPointerSize ==
   4738                 JSObject::kElementsOffset);
   4739   STATIC_ASSERT(JSGeneratorObject::kResultValuePropertyOffset + kPointerSize ==
   4740                 JSGeneratorObject::kResultDonePropertyOffset);
   4741   __ ObjectUntag(untagged_result, result);
   4742   __ Str(map_reg, MemOperand(untagged_result, HeapObject::kMapOffset));
   4743   __ Stp(empty_fixed_array, empty_fixed_array,
   4744          MemOperand(untagged_result, JSObject::kPropertiesOffset));
   4745   __ Stp(result_value, boolean_done,
   4746          MemOperand(untagged_result,
   4747                     JSGeneratorObject::kResultValuePropertyOffset));
   4748 
   4749   // Only the value field needs a write barrier, as the other values are in the
   4750   // root set.
   4751   __ RecordWriteField(result, JSGeneratorObject::kResultValuePropertyOffset,
   4752                       x10, x11, kLRHasBeenSaved, kDontSaveFPRegs);
   4753 }
   4754 
   4755 
   4756 // TODO(all): I don't like this method.
   4757 // It seems to me that in too many places x0 is used in place of this.
   4758 // Also, this function is not suitable for all places where x0 should be
   4759 // abstracted (eg. when used as an argument). But some places assume that the
   4760 // first argument register is x0, and use this function instead.
   4761 // Considering that most of the register allocation is hard-coded in the
   4762 // FullCodeGen, that it is unlikely we will need to change it extensively, and
   4763 // that abstracting the allocation through functions would not yield any
   4764 // performance benefit, I think the existence of this function is debatable.
   4765 Register FullCodeGenerator::result_register() {
   4766   return x0;
   4767 }
   4768 
   4769 
   4770 Register FullCodeGenerator::context_register() {
   4771   return cp;
   4772 }
   4773 
   4774 
   4775 void FullCodeGenerator::StoreToFrameField(int frame_offset, Register value) {
   4776   DCHECK(POINTER_SIZE_ALIGN(frame_offset) == frame_offset);
   4777   __ Str(value, MemOperand(fp, frame_offset));
   4778 }
   4779 
   4780 
   4781 void FullCodeGenerator::LoadContextField(Register dst, int context_index) {
   4782   __ Ldr(dst, ContextMemOperand(cp, context_index));
   4783 }
   4784 
   4785 
   4786 void FullCodeGenerator::PushFunctionArgumentForContextAllocation() {
   4787   Scope* declaration_scope = scope()->DeclarationScope();
   4788   if (declaration_scope->is_global_scope() ||
   4789       declaration_scope->is_module_scope()) {
   4790     // Contexts nested in the native context have a canonical empty function
   4791     // as their closure, not the anonymous closure containing the global
   4792     // code.  Pass a smi sentinel and let the runtime look up the empty
   4793     // function.
   4794     DCHECK(kSmiTag == 0);
   4795     __ Push(xzr);
   4796   } else if (declaration_scope->is_eval_scope()) {
   4797     // Contexts created by a call to eval have the same closure as the
   4798     // context calling eval, not the anonymous closure containing the eval
   4799     // code.  Fetch it from the context.
   4800     __ Ldr(x10, ContextMemOperand(cp, Context::CLOSURE_INDEX));
   4801     __ Push(x10);
   4802   } else {
   4803     DCHECK(declaration_scope->is_function_scope());
   4804     __ Ldr(x10, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   4805     __ Push(x10);
   4806   }
   4807 }
   4808 
   4809 
   4810 void FullCodeGenerator::EnterFinallyBlock() {
   4811   ASM_LOCATION("FullCodeGenerator::EnterFinallyBlock");
   4812   DCHECK(!result_register().is(x10));
   4813   // Preserve the result register while executing finally block.
   4814   // Also cook the return address in lr to the stack (smi encoded Code* delta).
   4815   __ Sub(x10, lr, Operand(masm_->CodeObject()));
   4816   __ SmiTag(x10);
   4817   __ Push(result_register(), x10);
   4818 
   4819   // Store pending message while executing finally block.
   4820   ExternalReference pending_message_obj =
   4821       ExternalReference::address_of_pending_message_obj(isolate());
   4822   __ Mov(x10, pending_message_obj);
   4823   __ Ldr(x10, MemOperand(x10));
   4824 
   4825   ExternalReference has_pending_message =
   4826       ExternalReference::address_of_has_pending_message(isolate());
   4827   STATIC_ASSERT(sizeof(bool) == 1);   // NOLINT(runtime/sizeof)
   4828   __ Mov(x11, has_pending_message);
   4829   __ Ldrb(x11, MemOperand(x11));
   4830   __ SmiTag(x11);
   4831 
   4832   __ Push(x10, x11);
   4833 
   4834   ExternalReference pending_message_script =
   4835       ExternalReference::address_of_pending_message_script(isolate());
   4836   __ Mov(x10, pending_message_script);
   4837   __ Ldr(x10, MemOperand(x10));
   4838   __ Push(x10);
   4839 }
   4840 
   4841 
   4842 void FullCodeGenerator::ExitFinallyBlock() {
   4843   ASM_LOCATION("FullCodeGenerator::ExitFinallyBlock");
   4844   DCHECK(!result_register().is(x10));
   4845 
   4846   // Restore pending message from stack.
   4847   __ Pop(x10, x11, x12);
   4848   ExternalReference pending_message_script =
   4849       ExternalReference::address_of_pending_message_script(isolate());
   4850   __ Mov(x13, pending_message_script);
   4851   __ Str(x10, MemOperand(x13));
   4852 
   4853   __ SmiUntag(x11);
   4854   ExternalReference has_pending_message =
   4855       ExternalReference::address_of_has_pending_message(isolate());
   4856   __ Mov(x13, has_pending_message);
   4857   STATIC_ASSERT(sizeof(bool) == 1);   // NOLINT(runtime/sizeof)
   4858   __ Strb(x11, MemOperand(x13));
   4859 
   4860   ExternalReference pending_message_obj =
   4861       ExternalReference::address_of_pending_message_obj(isolate());
   4862   __ Mov(x13, pending_message_obj);
   4863   __ Str(x12, MemOperand(x13));
   4864 
   4865   // Restore result register and cooked return address from the stack.
   4866   __ Pop(x10, result_register());
   4867 
   4868   // Uncook the return address (see EnterFinallyBlock).
   4869   __ SmiUntag(x10);
   4870   __ Add(x11, x10, Operand(masm_->CodeObject()));
   4871   __ Br(x11);
   4872 }
   4873 
   4874 
   4875 #undef __
   4876 
   4877 
   4878 void BackEdgeTable::PatchAt(Code* unoptimized_code,
   4879                             Address pc,
   4880                             BackEdgeState target_state,
   4881                             Code* replacement_code) {
   4882   // Turn the jump into a nop.
   4883   Address branch_address = pc - 3 * kInstructionSize;
   4884   PatchingAssembler patcher(branch_address, 1);
   4885 
   4886   DCHECK(Instruction::Cast(branch_address)
   4887              ->IsNop(Assembler::INTERRUPT_CODE_NOP) ||
   4888          (Instruction::Cast(branch_address)->IsCondBranchImm() &&
   4889           Instruction::Cast(branch_address)->ImmPCOffset() ==
   4890               6 * kInstructionSize));
   4891 
   4892   switch (target_state) {
   4893     case INTERRUPT:
   4894       //  <decrement profiling counter>
   4895       //  .. .. .. ..       b.pl ok
   4896       //  .. .. .. ..       ldr x16, pc+<interrupt stub address>
   4897       //  .. .. .. ..       blr x16
   4898       //  ... more instructions.
   4899       //  ok-label
   4900       // Jump offset is 6 instructions.
   4901       patcher.b(6, pl);
   4902       break;
   4903     case ON_STACK_REPLACEMENT:
   4904     case OSR_AFTER_STACK_CHECK:
   4905       //  <decrement profiling counter>
   4906       //  .. .. .. ..       mov x0, x0 (NOP)
   4907       //  .. .. .. ..       ldr x16, pc+<on-stack replacement address>
   4908       //  .. .. .. ..       blr x16
   4909       patcher.nop(Assembler::INTERRUPT_CODE_NOP);
   4910       break;
   4911   }
   4912 
   4913   // Replace the call address.
   4914   Instruction* load = Instruction::Cast(pc)->preceding(2);
   4915   Address interrupt_address_pointer =
   4916       reinterpret_cast<Address>(load) + load->ImmPCOffset();
   4917   DCHECK((Memory::uint64_at(interrupt_address_pointer) ==
   4918           reinterpret_cast<uint64_t>(unoptimized_code->GetIsolate()
   4919                                          ->builtins()
   4920                                          ->OnStackReplacement()
   4921                                          ->entry())) ||
   4922          (Memory::uint64_at(interrupt_address_pointer) ==
   4923           reinterpret_cast<uint64_t>(unoptimized_code->GetIsolate()
   4924                                          ->builtins()
   4925                                          ->InterruptCheck()
   4926                                          ->entry())) ||
   4927          (Memory::uint64_at(interrupt_address_pointer) ==
   4928           reinterpret_cast<uint64_t>(unoptimized_code->GetIsolate()
   4929                                          ->builtins()
   4930                                          ->OsrAfterStackCheck()
   4931                                          ->entry())) ||
   4932          (Memory::uint64_at(interrupt_address_pointer) ==
   4933           reinterpret_cast<uint64_t>(unoptimized_code->GetIsolate()
   4934                                          ->builtins()
   4935                                          ->OnStackReplacement()
   4936                                          ->entry())));
   4937   Memory::uint64_at(interrupt_address_pointer) =
   4938       reinterpret_cast<uint64_t>(replacement_code->entry());
   4939 
   4940   unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
   4941       unoptimized_code, reinterpret_cast<Address>(load), replacement_code);
   4942 }
   4943 
   4944 
   4945 BackEdgeTable::BackEdgeState BackEdgeTable::GetBackEdgeState(
   4946     Isolate* isolate,
   4947     Code* unoptimized_code,
   4948     Address pc) {
   4949   // TODO(jbramley): There should be some extra assertions here (as in the ARM
   4950   // back-end), but this function is gone in bleeding_edge so it might not
   4951   // matter anyway.
   4952   Instruction* jump_or_nop = Instruction::Cast(pc)->preceding(3);
   4953 
   4954   if (jump_or_nop->IsNop(Assembler::INTERRUPT_CODE_NOP)) {
   4955     Instruction* load = Instruction::Cast(pc)->preceding(2);
   4956     uint64_t entry = Memory::uint64_at(reinterpret_cast<Address>(load) +
   4957                                        load->ImmPCOffset());
   4958     if (entry == reinterpret_cast<uint64_t>(
   4959         isolate->builtins()->OnStackReplacement()->entry())) {
   4960       return ON_STACK_REPLACEMENT;
   4961     } else if (entry == reinterpret_cast<uint64_t>(
   4962         isolate->builtins()->OsrAfterStackCheck()->entry())) {
   4963       return OSR_AFTER_STACK_CHECK;
   4964     } else {
   4965       UNREACHABLE();
   4966     }
   4967   }
   4968 
   4969   return INTERRUPT;
   4970 }
   4971 
   4972 
   4973 #define __ ACCESS_MASM(masm())
   4974 
   4975 
   4976 FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
   4977     int* stack_depth,
   4978     int* context_length) {
   4979   ASM_LOCATION("FullCodeGenerator::TryFinally::Exit");
   4980   // The macros used here must preserve the result register.
   4981 
   4982   // Because the handler block contains the context of the finally
   4983   // code, we can restore it directly from there for the finally code
   4984   // rather than iteratively unwinding contexts via their previous
   4985   // links.
   4986   __ Drop(*stack_depth);  // Down to the handler block.
   4987   if (*context_length > 0) {
   4988     // Restore the context to its dedicated register and the stack.
   4989     __ Peek(cp, StackHandlerConstants::kContextOffset);
   4990     __ Str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   4991   }
   4992   __ PopTryHandler();
   4993   __ Bl(finally_entry_);
   4994 
   4995   *stack_depth = 0;
   4996   *context_length = 0;
   4997   return previous_;
   4998 }
   4999 
   5000 
   5001 #undef __
   5002 
   5003 
   5004 } }  // namespace v8::internal
   5005 
   5006 #endif  // V8_TARGET_ARCH_ARM64
   5007