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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 #include "src/arm64/lithium-codegen-arm64.h"
      8 #include "src/hydrogen-osr.h"
      9 #include "src/lithium-inl.h"
     10 
     11 namespace v8 {
     12 namespace internal {
     13 
     14 #define DEFINE_COMPILE(type)                            \
     15   void L##type::CompileToNative(LCodeGen* generator) {  \
     16     generator->Do##type(this);                          \
     17   }
     18 LITHIUM_CONCRETE_INSTRUCTION_LIST(DEFINE_COMPILE)
     19 #undef DEFINE_COMPILE
     20 
     21 #ifdef DEBUG
     22 void LInstruction::VerifyCall() {
     23   // Call instructions can use only fixed registers as temporaries and
     24   // outputs because all registers are blocked by the calling convention.
     25   // Inputs operands must use a fixed register or use-at-start policy or
     26   // a non-register policy.
     27   DCHECK(Output() == NULL ||
     28          LUnallocated::cast(Output())->HasFixedPolicy() ||
     29          !LUnallocated::cast(Output())->HasRegisterPolicy());
     30   for (UseIterator it(this); !it.Done(); it.Advance()) {
     31     LUnallocated* operand = LUnallocated::cast(it.Current());
     32     DCHECK(operand->HasFixedPolicy() ||
     33            operand->IsUsedAtStart());
     34   }
     35   for (TempIterator it(this); !it.Done(); it.Advance()) {
     36     LUnallocated* operand = LUnallocated::cast(it.Current());
     37     DCHECK(operand->HasFixedPolicy() ||!operand->HasRegisterPolicy());
     38   }
     39 }
     40 #endif
     41 
     42 
     43 void LLabel::PrintDataTo(StringStream* stream) {
     44   LGap::PrintDataTo(stream);
     45   LLabel* rep = replacement();
     46   if (rep != NULL) {
     47     stream->Add(" Dead block replaced with B%d", rep->block_id());
     48   }
     49 }
     50 
     51 
     52 void LAccessArgumentsAt::PrintDataTo(StringStream* stream) {
     53   arguments()->PrintTo(stream);
     54   stream->Add(" length ");
     55   length()->PrintTo(stream);
     56   stream->Add(" index ");
     57   index()->PrintTo(stream);
     58 }
     59 
     60 
     61 void LBranch::PrintDataTo(StringStream* stream) {
     62   stream->Add("B%d | B%d on ", true_block_id(), false_block_id());
     63   value()->PrintTo(stream);
     64 }
     65 
     66 
     67 void LCallJSFunction::PrintDataTo(StringStream* stream) {
     68   stream->Add("= ");
     69   function()->PrintTo(stream);
     70   stream->Add("#%d / ", arity());
     71 }
     72 
     73 
     74 void LCallWithDescriptor::PrintDataTo(StringStream* stream) {
     75   for (int i = 0; i < InputCount(); i++) {
     76     InputAt(i)->PrintTo(stream);
     77     stream->Add(" ");
     78   }
     79   stream->Add("#%d / ", arity());
     80 }
     81 
     82 
     83 void LCallNew::PrintDataTo(StringStream* stream) {
     84   stream->Add("= ");
     85   constructor()->PrintTo(stream);
     86   stream->Add(" #%d / ", arity());
     87 }
     88 
     89 
     90 void LCallNewArray::PrintDataTo(StringStream* stream) {
     91   stream->Add("= ");
     92   constructor()->PrintTo(stream);
     93   stream->Add(" #%d / ", arity());
     94   ElementsKind kind = hydrogen()->elements_kind();
     95   stream->Add(" (%s) ", ElementsKindToString(kind));
     96 }
     97 
     98 
     99 void LClassOfTestAndBranch::PrintDataTo(StringStream* stream) {
    100   stream->Add("if class_of_test(");
    101   value()->PrintTo(stream);
    102   stream->Add(", \"%o\") then B%d else B%d",
    103               *hydrogen()->class_name(),
    104               true_block_id(),
    105               false_block_id());
    106 }
    107 
    108 
    109 void LCompareNumericAndBranch::PrintDataTo(StringStream* stream) {
    110   stream->Add("if ");
    111   left()->PrintTo(stream);
    112   stream->Add(" %s ", Token::String(op()));
    113   right()->PrintTo(stream);
    114   stream->Add(" then B%d else B%d", true_block_id(), false_block_id());
    115 }
    116 
    117 
    118 void LHasCachedArrayIndexAndBranch::PrintDataTo(StringStream* stream) {
    119   stream->Add("if has_cached_array_index(");
    120   value()->PrintTo(stream);
    121   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    122 }
    123 
    124 
    125 bool LGoto::HasInterestingComment(LCodeGen* gen) const {
    126   return !gen->IsNextEmittedBlock(block_id());
    127 }
    128 
    129 
    130 void LGoto::PrintDataTo(StringStream* stream) {
    131   stream->Add("B%d", block_id());
    132 }
    133 
    134 
    135 void LInnerAllocatedObject::PrintDataTo(StringStream* stream) {
    136   stream->Add(" = ");
    137   base_object()->PrintTo(stream);
    138   stream->Add(" + ");
    139   offset()->PrintTo(stream);
    140 }
    141 
    142 
    143 void LInvokeFunction::PrintDataTo(StringStream* stream) {
    144   stream->Add("= ");
    145   function()->PrintTo(stream);
    146   stream->Add(" #%d / ", arity());
    147 }
    148 
    149 
    150 void LInstruction::PrintTo(StringStream* stream) {
    151   stream->Add("%s ", this->Mnemonic());
    152 
    153   PrintOutputOperandTo(stream);
    154 
    155   PrintDataTo(stream);
    156 
    157   if (HasEnvironment()) {
    158     stream->Add(" ");
    159     environment()->PrintTo(stream);
    160   }
    161 
    162   if (HasPointerMap()) {
    163     stream->Add(" ");
    164     pointer_map()->PrintTo(stream);
    165   }
    166 }
    167 
    168 
    169 void LInstruction::PrintDataTo(StringStream* stream) {
    170   stream->Add("= ");
    171   for (int i = 0; i < InputCount(); i++) {
    172     if (i > 0) stream->Add(" ");
    173     if (InputAt(i) == NULL) {
    174       stream->Add("NULL");
    175     } else {
    176       InputAt(i)->PrintTo(stream);
    177     }
    178   }
    179 }
    180 
    181 
    182 void LInstruction::PrintOutputOperandTo(StringStream* stream) {
    183   if (HasResult()) result()->PrintTo(stream);
    184 }
    185 
    186 
    187 void LHasInstanceTypeAndBranch::PrintDataTo(StringStream* stream) {
    188   stream->Add("if has_instance_type(");
    189   value()->PrintTo(stream);
    190   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    191 }
    192 
    193 
    194 void LIsObjectAndBranch::PrintDataTo(StringStream* stream) {
    195   stream->Add("if is_object(");
    196   value()->PrintTo(stream);
    197   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    198 }
    199 
    200 
    201 void LIsStringAndBranch::PrintDataTo(StringStream* stream) {
    202   stream->Add("if is_string(");
    203   value()->PrintTo(stream);
    204   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    205 }
    206 
    207 
    208 void LIsSmiAndBranch::PrintDataTo(StringStream* stream) {
    209   stream->Add("if is_smi(");
    210   value()->PrintTo(stream);
    211   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    212 }
    213 
    214 
    215 void LTypeofIsAndBranch::PrintDataTo(StringStream* stream) {
    216   stream->Add("if typeof ");
    217   value()->PrintTo(stream);
    218   stream->Add(" == \"%s\" then B%d else B%d",
    219               hydrogen()->type_literal()->ToCString().get(),
    220               true_block_id(), false_block_id());
    221 }
    222 
    223 
    224 void LIsUndetectableAndBranch::PrintDataTo(StringStream* stream) {
    225   stream->Add("if is_undetectable(");
    226   value()->PrintTo(stream);
    227   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    228 }
    229 
    230 
    231 bool LGap::IsRedundant() const {
    232   for (int i = 0; i < 4; i++) {
    233     if ((parallel_moves_[i] != NULL) && !parallel_moves_[i]->IsRedundant()) {
    234       return false;
    235     }
    236   }
    237 
    238   return true;
    239 }
    240 
    241 
    242 void LGap::PrintDataTo(StringStream* stream) {
    243   for (int i = 0; i < 4; i++) {
    244     stream->Add("(");
    245     if (parallel_moves_[i] != NULL) {
    246       parallel_moves_[i]->PrintDataTo(stream);
    247     }
    248     stream->Add(") ");
    249   }
    250 }
    251 
    252 
    253 void LLoadContextSlot::PrintDataTo(StringStream* stream) {
    254   context()->PrintTo(stream);
    255   stream->Add("[%d]", slot_index());
    256 }
    257 
    258 
    259 void LStoreCodeEntry::PrintDataTo(StringStream* stream) {
    260   stream->Add(" = ");
    261   function()->PrintTo(stream);
    262   stream->Add(".code_entry = ");
    263   code_object()->PrintTo(stream);
    264 }
    265 
    266 
    267 void LStoreContextSlot::PrintDataTo(StringStream* stream) {
    268   context()->PrintTo(stream);
    269   stream->Add("[%d] <- ", slot_index());
    270   value()->PrintTo(stream);
    271 }
    272 
    273 
    274 void LStoreKeyedGeneric::PrintDataTo(StringStream* stream) {
    275   object()->PrintTo(stream);
    276   stream->Add("[");
    277   key()->PrintTo(stream);
    278   stream->Add("] <- ");
    279   value()->PrintTo(stream);
    280 }
    281 
    282 
    283 void LStoreNamedField::PrintDataTo(StringStream* stream) {
    284   object()->PrintTo(stream);
    285   OStringStream os;
    286   os << hydrogen()->access();
    287   stream->Add(os.c_str());
    288   stream->Add(" <- ");
    289   value()->PrintTo(stream);
    290 }
    291 
    292 
    293 void LStoreNamedGeneric::PrintDataTo(StringStream* stream) {
    294   object()->PrintTo(stream);
    295   stream->Add(".");
    296   stream->Add(String::cast(*name())->ToCString().get());
    297   stream->Add(" <- ");
    298   value()->PrintTo(stream);
    299 }
    300 
    301 
    302 void LStringCompareAndBranch::PrintDataTo(StringStream* stream) {
    303   stream->Add("if string_compare(");
    304   left()->PrintTo(stream);
    305   right()->PrintTo(stream);
    306   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    307 }
    308 
    309 
    310 void LTransitionElementsKind::PrintDataTo(StringStream* stream) {
    311   object()->PrintTo(stream);
    312   stream->Add("%p -> %p", *original_map(), *transitioned_map());
    313 }
    314 
    315 
    316 template<int T>
    317 void LUnaryMathOperation<T>::PrintDataTo(StringStream* stream) {
    318   value()->PrintTo(stream);
    319 }
    320 
    321 
    322 const char* LArithmeticD::Mnemonic() const {
    323   switch (op()) {
    324     case Token::ADD: return "add-d";
    325     case Token::SUB: return "sub-d";
    326     case Token::MUL: return "mul-d";
    327     case Token::DIV: return "div-d";
    328     case Token::MOD: return "mod-d";
    329     default:
    330       UNREACHABLE();
    331       return NULL;
    332   }
    333 }
    334 
    335 
    336 const char* LArithmeticT::Mnemonic() const {
    337   switch (op()) {
    338     case Token::ADD: return "add-t";
    339     case Token::SUB: return "sub-t";
    340     case Token::MUL: return "mul-t";
    341     case Token::MOD: return "mod-t";
    342     case Token::DIV: return "div-t";
    343     case Token::BIT_AND: return "bit-and-t";
    344     case Token::BIT_OR: return "bit-or-t";
    345     case Token::BIT_XOR: return "bit-xor-t";
    346     case Token::ROR: return "ror-t";
    347     case Token::SHL: return "shl-t";
    348     case Token::SAR: return "sar-t";
    349     case Token::SHR: return "shr-t";
    350     default:
    351       UNREACHABLE();
    352       return NULL;
    353   }
    354 }
    355 
    356 
    357 LUnallocated* LChunkBuilder::ToUnallocated(Register reg) {
    358   return new(zone()) LUnallocated(LUnallocated::FIXED_REGISTER,
    359                                   Register::ToAllocationIndex(reg));
    360 }
    361 
    362 
    363 LUnallocated* LChunkBuilder::ToUnallocated(DoubleRegister reg) {
    364   return new(zone()) LUnallocated(LUnallocated::FIXED_DOUBLE_REGISTER,
    365                                   DoubleRegister::ToAllocationIndex(reg));
    366 }
    367 
    368 
    369 LOperand* LChunkBuilder::Use(HValue* value, LUnallocated* operand) {
    370   if (value->EmitAtUses()) {
    371     HInstruction* instr = HInstruction::cast(value);
    372     VisitInstruction(instr);
    373   }
    374   operand->set_virtual_register(value->id());
    375   return operand;
    376 }
    377 
    378 
    379 LOperand* LChunkBuilder::UseFixed(HValue* value, Register fixed_register) {
    380   return Use(value, ToUnallocated(fixed_register));
    381 }
    382 
    383 
    384 LOperand* LChunkBuilder::UseFixedDouble(HValue* value,
    385                                         DoubleRegister fixed_register) {
    386   return Use(value, ToUnallocated(fixed_register));
    387 }
    388 
    389 
    390 LOperand* LChunkBuilder::UseRegister(HValue* value) {
    391   return Use(value, new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER));
    392 }
    393 
    394 
    395 LOperand* LChunkBuilder::UseRegisterAndClobber(HValue* value) {
    396   return Use(value, new(zone()) LUnallocated(LUnallocated::WRITABLE_REGISTER));
    397 }
    398 
    399 
    400 LOperand* LChunkBuilder::UseRegisterAtStart(HValue* value) {
    401   return Use(value,
    402              new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER,
    403                                       LUnallocated::USED_AT_START));
    404 }
    405 
    406 
    407 LOperand* LChunkBuilder::UseRegisterOrConstant(HValue* value) {
    408   return value->IsConstant() ? UseConstant(value) : UseRegister(value);
    409 }
    410 
    411 
    412 LOperand* LChunkBuilder::UseRegisterOrConstantAtStart(HValue* value) {
    413   return value->IsConstant() ? UseConstant(value) : UseRegisterAtStart(value);
    414 }
    415 
    416 
    417 LConstantOperand* LChunkBuilder::UseConstant(HValue* value) {
    418   return chunk_->DefineConstantOperand(HConstant::cast(value));
    419 }
    420 
    421 
    422 LOperand* LChunkBuilder::UseAny(HValue* value) {
    423   return value->IsConstant()
    424       ? UseConstant(value)
    425       : Use(value, new(zone()) LUnallocated(LUnallocated::ANY));
    426 }
    427 
    428 
    429 LInstruction* LChunkBuilder::Define(LTemplateResultInstruction<1>* instr,
    430                                     LUnallocated* result) {
    431   result->set_virtual_register(current_instruction_->id());
    432   instr->set_result(result);
    433   return instr;
    434 }
    435 
    436 
    437 LInstruction* LChunkBuilder::DefineAsRegister(
    438     LTemplateResultInstruction<1>* instr) {
    439   return Define(instr,
    440                 new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER));
    441 }
    442 
    443 
    444 LInstruction* LChunkBuilder::DefineAsSpilled(
    445     LTemplateResultInstruction<1>* instr, int index) {
    446   return Define(instr,
    447                 new(zone()) LUnallocated(LUnallocated::FIXED_SLOT, index));
    448 }
    449 
    450 
    451 LInstruction* LChunkBuilder::DefineSameAsFirst(
    452     LTemplateResultInstruction<1>* instr) {
    453   return Define(instr,
    454                 new(zone()) LUnallocated(LUnallocated::SAME_AS_FIRST_INPUT));
    455 }
    456 
    457 
    458 LInstruction* LChunkBuilder::DefineFixed(
    459     LTemplateResultInstruction<1>* instr, Register reg) {
    460   return Define(instr, ToUnallocated(reg));
    461 }
    462 
    463 
    464 LInstruction* LChunkBuilder::DefineFixedDouble(
    465     LTemplateResultInstruction<1>* instr, DoubleRegister reg) {
    466   return Define(instr, ToUnallocated(reg));
    467 }
    468 
    469 
    470 LInstruction* LChunkBuilder::MarkAsCall(LInstruction* instr,
    471                                         HInstruction* hinstr,
    472                                         CanDeoptimize can_deoptimize) {
    473   info()->MarkAsNonDeferredCalling();
    474 #ifdef DEBUG
    475   instr->VerifyCall();
    476 #endif
    477   instr->MarkAsCall();
    478   instr = AssignPointerMap(instr);
    479 
    480   // If instruction does not have side-effects lazy deoptimization
    481   // after the call will try to deoptimize to the point before the call.
    482   // Thus we still need to attach environment to this call even if
    483   // call sequence can not deoptimize eagerly.
    484   bool needs_environment =
    485       (can_deoptimize == CAN_DEOPTIMIZE_EAGERLY) ||
    486       !hinstr->HasObservableSideEffects();
    487   if (needs_environment && !instr->HasEnvironment()) {
    488     instr = AssignEnvironment(instr);
    489     // We can't really figure out if the environment is needed or not.
    490     instr->environment()->set_has_been_used();
    491   }
    492 
    493   return instr;
    494 }
    495 
    496 
    497 LInstruction* LChunkBuilder::AssignPointerMap(LInstruction* instr) {
    498   DCHECK(!instr->HasPointerMap());
    499   instr->set_pointer_map(new(zone()) LPointerMap(zone()));
    500   return instr;
    501 }
    502 
    503 
    504 LUnallocated* LChunkBuilder::TempRegister() {
    505   LUnallocated* operand =
    506       new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER);
    507   int vreg = allocator_->GetVirtualRegister();
    508   if (!allocator_->AllocationOk()) {
    509     Abort(kOutOfVirtualRegistersWhileTryingToAllocateTempRegister);
    510     vreg = 0;
    511   }
    512   operand->set_virtual_register(vreg);
    513   return operand;
    514 }
    515 
    516 
    517 LUnallocated* LChunkBuilder::TempDoubleRegister() {
    518   LUnallocated* operand =
    519       new(zone()) LUnallocated(LUnallocated::MUST_HAVE_DOUBLE_REGISTER);
    520   int vreg = allocator_->GetVirtualRegister();
    521   if (!allocator_->AllocationOk()) {
    522     Abort(kOutOfVirtualRegistersWhileTryingToAllocateTempRegister);
    523     vreg = 0;
    524   }
    525   operand->set_virtual_register(vreg);
    526   return operand;
    527 }
    528 
    529 
    530 int LPlatformChunk::GetNextSpillIndex() {
    531   return spill_slot_count_++;
    532 }
    533 
    534 
    535 LOperand* LPlatformChunk::GetNextSpillSlot(RegisterKind kind) {
    536   int index = GetNextSpillIndex();
    537   if (kind == DOUBLE_REGISTERS) {
    538     return LDoubleStackSlot::Create(index, zone());
    539   } else {
    540     DCHECK(kind == GENERAL_REGISTERS);
    541     return LStackSlot::Create(index, zone());
    542   }
    543 }
    544 
    545 
    546 LOperand* LChunkBuilder::FixedTemp(Register reg) {
    547   LUnallocated* operand = ToUnallocated(reg);
    548   DCHECK(operand->HasFixedPolicy());
    549   return operand;
    550 }
    551 
    552 
    553 LOperand* LChunkBuilder::FixedTemp(DoubleRegister reg) {
    554   LUnallocated* operand = ToUnallocated(reg);
    555   DCHECK(operand->HasFixedPolicy());
    556   return operand;
    557 }
    558 
    559 
    560 LPlatformChunk* LChunkBuilder::Build() {
    561   DCHECK(is_unused());
    562   chunk_ = new(zone()) LPlatformChunk(info_, graph_);
    563   LPhase phase("L_Building chunk", chunk_);
    564   status_ = BUILDING;
    565 
    566   // If compiling for OSR, reserve space for the unoptimized frame,
    567   // which will be subsumed into this frame.
    568   if (graph()->has_osr()) {
    569     // TODO(all): GetNextSpillIndex just increments a field. It has no other
    570     // side effects, so we should get rid of this loop.
    571     for (int i = graph()->osr()->UnoptimizedFrameSlots(); i > 0; i--) {
    572       chunk_->GetNextSpillIndex();
    573     }
    574   }
    575 
    576   const ZoneList<HBasicBlock*>* blocks = graph_->blocks();
    577   for (int i = 0; i < blocks->length(); i++) {
    578     DoBasicBlock(blocks->at(i));
    579     if (is_aborted()) return NULL;
    580   }
    581   status_ = DONE;
    582   return chunk_;
    583 }
    584 
    585 
    586 void LChunkBuilder::DoBasicBlock(HBasicBlock* block) {
    587   DCHECK(is_building());
    588   current_block_ = block;
    589 
    590   if (block->IsStartBlock()) {
    591     block->UpdateEnvironment(graph_->start_environment());
    592     argument_count_ = 0;
    593   } else if (block->predecessors()->length() == 1) {
    594     // We have a single predecessor => copy environment and outgoing
    595     // argument count from the predecessor.
    596     DCHECK(block->phis()->length() == 0);
    597     HBasicBlock* pred = block->predecessors()->at(0);
    598     HEnvironment* last_environment = pred->last_environment();
    599     DCHECK(last_environment != NULL);
    600 
    601     // Only copy the environment, if it is later used again.
    602     if (pred->end()->SecondSuccessor() == NULL) {
    603       DCHECK(pred->end()->FirstSuccessor() == block);
    604     } else {
    605       if ((pred->end()->FirstSuccessor()->block_id() > block->block_id()) ||
    606           (pred->end()->SecondSuccessor()->block_id() > block->block_id())) {
    607         last_environment = last_environment->Copy();
    608       }
    609     }
    610     block->UpdateEnvironment(last_environment);
    611     DCHECK(pred->argument_count() >= 0);
    612     argument_count_ = pred->argument_count();
    613   } else {
    614     // We are at a state join => process phis.
    615     HBasicBlock* pred = block->predecessors()->at(0);
    616     // No need to copy the environment, it cannot be used later.
    617     HEnvironment* last_environment = pred->last_environment();
    618     for (int i = 0; i < block->phis()->length(); ++i) {
    619       HPhi* phi = block->phis()->at(i);
    620       if (phi->HasMergedIndex()) {
    621         last_environment->SetValueAt(phi->merged_index(), phi);
    622       }
    623     }
    624     for (int i = 0; i < block->deleted_phis()->length(); ++i) {
    625       if (block->deleted_phis()->at(i) < last_environment->length()) {
    626         last_environment->SetValueAt(block->deleted_phis()->at(i),
    627                                      graph_->GetConstantUndefined());
    628       }
    629     }
    630     block->UpdateEnvironment(last_environment);
    631     // Pick up the outgoing argument count of one of the predecessors.
    632     argument_count_ = pred->argument_count();
    633   }
    634 
    635   // Translate hydrogen instructions to lithium ones for the current block.
    636   HInstruction* current = block->first();
    637   int start = chunk_->instructions()->length();
    638   while ((current != NULL) && !is_aborted()) {
    639     // Code for constants in registers is generated lazily.
    640     if (!current->EmitAtUses()) {
    641       VisitInstruction(current);
    642     }
    643     current = current->next();
    644   }
    645   int end = chunk_->instructions()->length() - 1;
    646   if (end >= start) {
    647     block->set_first_instruction_index(start);
    648     block->set_last_instruction_index(end);
    649   }
    650   block->set_argument_count(argument_count_);
    651   current_block_ = NULL;
    652 }
    653 
    654 
    655 void LChunkBuilder::VisitInstruction(HInstruction* current) {
    656   HInstruction* old_current = current_instruction_;
    657   current_instruction_ = current;
    658 
    659   LInstruction* instr = NULL;
    660   if (current->CanReplaceWithDummyUses()) {
    661     if (current->OperandCount() == 0) {
    662       instr = DefineAsRegister(new(zone()) LDummy());
    663     } else {
    664       DCHECK(!current->OperandAt(0)->IsControlInstruction());
    665       instr = DefineAsRegister(new(zone())
    666           LDummyUse(UseAny(current->OperandAt(0))));
    667     }
    668     for (int i = 1; i < current->OperandCount(); ++i) {
    669       if (current->OperandAt(i)->IsControlInstruction()) continue;
    670       LInstruction* dummy =
    671           new(zone()) LDummyUse(UseAny(current->OperandAt(i)));
    672       dummy->set_hydrogen_value(current);
    673       chunk_->AddInstruction(dummy, current_block_);
    674     }
    675   } else {
    676     HBasicBlock* successor;
    677     if (current->IsControlInstruction() &&
    678         HControlInstruction::cast(current)->KnownSuccessorBlock(&successor) &&
    679         successor != NULL) {
    680       instr = new(zone()) LGoto(successor);
    681     } else {
    682       instr = current->CompileToLithium(this);
    683     }
    684   }
    685 
    686   argument_count_ += current->argument_delta();
    687   DCHECK(argument_count_ >= 0);
    688 
    689   if (instr != NULL) {
    690     AddInstruction(instr, current);
    691   }
    692 
    693   current_instruction_ = old_current;
    694 }
    695 
    696 
    697 void LChunkBuilder::AddInstruction(LInstruction* instr,
    698                                    HInstruction* hydrogen_val) {
    699   // Associate the hydrogen instruction first, since we may need it for
    700   // the ClobbersRegisters() or ClobbersDoubleRegisters() calls below.
    701   instr->set_hydrogen_value(hydrogen_val);
    702 
    703 #if DEBUG
    704   // Make sure that the lithium instruction has either no fixed register
    705   // constraints in temps or the result OR no uses that are only used at
    706   // start. If this invariant doesn't hold, the register allocator can decide
    707   // to insert a split of a range immediately before the instruction due to an
    708   // already allocated register needing to be used for the instruction's fixed
    709   // register constraint. In this case, the register allocator won't see an
    710   // interference between the split child and the use-at-start (it would if
    711   // the it was just a plain use), so it is free to move the split child into
    712   // the same register that is used for the use-at-start.
    713   // See https://code.google.com/p/chromium/issues/detail?id=201590
    714   if (!(instr->ClobbersRegisters() &&
    715         instr->ClobbersDoubleRegisters(isolate()))) {
    716     int fixed = 0;
    717     int used_at_start = 0;
    718     for (UseIterator it(instr); !it.Done(); it.Advance()) {
    719       LUnallocated* operand = LUnallocated::cast(it.Current());
    720       if (operand->IsUsedAtStart()) ++used_at_start;
    721     }
    722     if (instr->Output() != NULL) {
    723       if (LUnallocated::cast(instr->Output())->HasFixedPolicy()) ++fixed;
    724     }
    725     for (TempIterator it(instr); !it.Done(); it.Advance()) {
    726       LUnallocated* operand = LUnallocated::cast(it.Current());
    727       if (operand->HasFixedPolicy()) ++fixed;
    728     }
    729     DCHECK(fixed == 0 || used_at_start == 0);
    730   }
    731 #endif
    732 
    733   if (FLAG_stress_pointer_maps && !instr->HasPointerMap()) {
    734     instr = AssignPointerMap(instr);
    735   }
    736   if (FLAG_stress_environments && !instr->HasEnvironment()) {
    737     instr = AssignEnvironment(instr);
    738   }
    739   chunk_->AddInstruction(instr, current_block_);
    740 
    741   if (instr->IsCall()) {
    742     HValue* hydrogen_value_for_lazy_bailout = hydrogen_val;
    743     LInstruction* instruction_needing_environment = NULL;
    744     if (hydrogen_val->HasObservableSideEffects()) {
    745       HSimulate* sim = HSimulate::cast(hydrogen_val->next());
    746       instruction_needing_environment = instr;
    747       sim->ReplayEnvironment(current_block_->last_environment());
    748       hydrogen_value_for_lazy_bailout = sim;
    749     }
    750     LInstruction* bailout = AssignEnvironment(new(zone()) LLazyBailout());
    751     bailout->set_hydrogen_value(hydrogen_value_for_lazy_bailout);
    752     chunk_->AddInstruction(bailout, current_block_);
    753     if (instruction_needing_environment != NULL) {
    754       // Store the lazy deopt environment with the instruction if needed.
    755       // Right now it is only used for LInstanceOfKnownGlobal.
    756       instruction_needing_environment->
    757           SetDeferredLazyDeoptimizationEnvironment(bailout->environment());
    758     }
    759   }
    760 }
    761 
    762 
    763 LInstruction* LChunkBuilder::AssignEnvironment(LInstruction* instr) {
    764   HEnvironment* hydrogen_env = current_block_->last_environment();
    765   int argument_index_accumulator = 0;
    766   ZoneList<HValue*> objects_to_materialize(0, zone());
    767   instr->set_environment(CreateEnvironment(hydrogen_env,
    768                                            &argument_index_accumulator,
    769                                            &objects_to_materialize));
    770   return instr;
    771 }
    772 
    773 
    774 LInstruction* LChunkBuilder::DoAbnormalExit(HAbnormalExit* instr) {
    775   // The control instruction marking the end of a block that completed
    776   // abruptly (e.g., threw an exception). There is nothing specific to do.
    777   return NULL;
    778 }
    779 
    780 
    781 LInstruction* LChunkBuilder::DoArithmeticD(Token::Value op,
    782                                            HArithmeticBinaryOperation* instr) {
    783   DCHECK(instr->representation().IsDouble());
    784   DCHECK(instr->left()->representation().IsDouble());
    785   DCHECK(instr->right()->representation().IsDouble());
    786 
    787   if (op == Token::MOD) {
    788     LOperand* left = UseFixedDouble(instr->left(), d0);
    789     LOperand* right = UseFixedDouble(instr->right(), d1);
    790     LArithmeticD* result = new(zone()) LArithmeticD(Token::MOD, left, right);
    791     return MarkAsCall(DefineFixedDouble(result, d0), instr);
    792   } else {
    793     LOperand* left = UseRegisterAtStart(instr->left());
    794     LOperand* right = UseRegisterAtStart(instr->right());
    795     LArithmeticD* result = new(zone()) LArithmeticD(op, left, right);
    796     return DefineAsRegister(result);
    797   }
    798 }
    799 
    800 
    801 LInstruction* LChunkBuilder::DoArithmeticT(Token::Value op,
    802                                            HBinaryOperation* instr) {
    803   DCHECK((op == Token::ADD) || (op == Token::SUB) || (op == Token::MUL) ||
    804          (op == Token::DIV) || (op == Token::MOD) || (op == Token::SHR) ||
    805          (op == Token::SHL) || (op == Token::SAR) || (op == Token::ROR) ||
    806          (op == Token::BIT_OR) || (op == Token::BIT_AND) ||
    807          (op == Token::BIT_XOR));
    808   HValue* left = instr->left();
    809   HValue* right = instr->right();
    810 
    811   // TODO(jbramley): Once we've implemented smi support for all arithmetic
    812   // operations, these assertions should check IsTagged().
    813   DCHECK(instr->representation().IsSmiOrTagged());
    814   DCHECK(left->representation().IsSmiOrTagged());
    815   DCHECK(right->representation().IsSmiOrTagged());
    816 
    817   LOperand* context = UseFixed(instr->context(), cp);
    818   LOperand* left_operand = UseFixed(left, x1);
    819   LOperand* right_operand = UseFixed(right, x0);
    820   LArithmeticT* result =
    821       new(zone()) LArithmeticT(op, context, left_operand, right_operand);
    822   return MarkAsCall(DefineFixed(result, x0), instr);
    823 }
    824 
    825 
    826 LInstruction* LChunkBuilder::DoBoundsCheckBaseIndexInformation(
    827     HBoundsCheckBaseIndexInformation* instr) {
    828   UNREACHABLE();
    829   return NULL;
    830 }
    831 
    832 
    833 LInstruction* LChunkBuilder::DoAccessArgumentsAt(HAccessArgumentsAt* instr) {
    834   info()->MarkAsRequiresFrame();
    835   LOperand* args = NULL;
    836   LOperand* length = NULL;
    837   LOperand* index = NULL;
    838 
    839   if (instr->length()->IsConstant() && instr->index()->IsConstant()) {
    840     args = UseRegisterAtStart(instr->arguments());
    841     length = UseConstant(instr->length());
    842     index = UseConstant(instr->index());
    843   } else {
    844     args = UseRegister(instr->arguments());
    845     length = UseRegisterAtStart(instr->length());
    846     index = UseRegisterOrConstantAtStart(instr->index());
    847   }
    848 
    849   return DefineAsRegister(new(zone()) LAccessArgumentsAt(args, length, index));
    850 }
    851 
    852 
    853 LInstruction* LChunkBuilder::DoAdd(HAdd* instr) {
    854   if (instr->representation().IsSmiOrInteger32()) {
    855     DCHECK(instr->left()->representation().Equals(instr->representation()));
    856     DCHECK(instr->right()->representation().Equals(instr->representation()));
    857 
    858     LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
    859     if (shifted_operation != NULL) {
    860       return shifted_operation;
    861     }
    862 
    863     LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand());
    864     LOperand* right =
    865         UseRegisterOrConstantAtStart(instr->BetterRightOperand());
    866     LInstruction* result = instr->representation().IsSmi() ?
    867         DefineAsRegister(new(zone()) LAddS(left, right)) :
    868         DefineAsRegister(new(zone()) LAddI(left, right));
    869     if (instr->CheckFlag(HValue::kCanOverflow)) {
    870       result = AssignEnvironment(result);
    871     }
    872     return result;
    873   } else if (instr->representation().IsExternal()) {
    874     DCHECK(instr->left()->representation().IsExternal());
    875     DCHECK(instr->right()->representation().IsInteger32());
    876     DCHECK(!instr->CheckFlag(HValue::kCanOverflow));
    877     LOperand* left = UseRegisterAtStart(instr->left());
    878     LOperand* right = UseRegisterOrConstantAtStart(instr->right());
    879     return DefineAsRegister(new(zone()) LAddE(left, right));
    880   } else if (instr->representation().IsDouble()) {
    881     return DoArithmeticD(Token::ADD, instr);
    882   } else {
    883     DCHECK(instr->representation().IsTagged());
    884     return DoArithmeticT(Token::ADD, instr);
    885   }
    886 }
    887 
    888 
    889 LInstruction* LChunkBuilder::DoAllocate(HAllocate* instr) {
    890   info()->MarkAsDeferredCalling();
    891   LOperand* context = UseAny(instr->context());
    892   LOperand* size = UseRegisterOrConstant(instr->size());
    893   LOperand* temp1 = TempRegister();
    894   LOperand* temp2 = TempRegister();
    895   LOperand* temp3 = instr->MustPrefillWithFiller() ? TempRegister() : NULL;
    896   LAllocate* result = new(zone()) LAllocate(context, size, temp1, temp2, temp3);
    897   return AssignPointerMap(DefineAsRegister(result));
    898 }
    899 
    900 
    901 LInstruction* LChunkBuilder::DoApplyArguments(HApplyArguments* instr) {
    902   LOperand* function = UseFixed(instr->function(), x1);
    903   LOperand* receiver = UseFixed(instr->receiver(), x0);
    904   LOperand* length = UseFixed(instr->length(), x2);
    905   LOperand* elements = UseFixed(instr->elements(), x3);
    906   LApplyArguments* result = new(zone()) LApplyArguments(function,
    907                                                         receiver,
    908                                                         length,
    909                                                         elements);
    910   return MarkAsCall(DefineFixed(result, x0), instr, CAN_DEOPTIMIZE_EAGERLY);
    911 }
    912 
    913 
    914 LInstruction* LChunkBuilder::DoArgumentsElements(HArgumentsElements* instr) {
    915   info()->MarkAsRequiresFrame();
    916   LOperand* temp = instr->from_inlined() ? NULL : TempRegister();
    917   return DefineAsRegister(new(zone()) LArgumentsElements(temp));
    918 }
    919 
    920 
    921 LInstruction* LChunkBuilder::DoArgumentsLength(HArgumentsLength* instr) {
    922   info()->MarkAsRequiresFrame();
    923   LOperand* value = UseRegisterAtStart(instr->value());
    924   return DefineAsRegister(new(zone()) LArgumentsLength(value));
    925 }
    926 
    927 
    928 LInstruction* LChunkBuilder::DoArgumentsObject(HArgumentsObject* instr) {
    929   // There are no real uses of the arguments object.
    930   // arguments.length and element access are supported directly on
    931   // stack arguments, and any real arguments object use causes a bailout.
    932   // So this value is never used.
    933   return NULL;
    934 }
    935 
    936 
    937 LInstruction* LChunkBuilder::DoBitwise(HBitwise* instr) {
    938   if (instr->representation().IsSmiOrInteger32()) {
    939     DCHECK(instr->left()->representation().Equals(instr->representation()));
    940     DCHECK(instr->right()->representation().Equals(instr->representation()));
    941     DCHECK(instr->CheckFlag(HValue::kTruncatingToInt32));
    942 
    943     LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
    944     if (shifted_operation != NULL) {
    945       return shifted_operation;
    946     }
    947 
    948     LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand());
    949     LOperand* right =
    950         UseRegisterOrConstantAtStart(instr->BetterRightOperand());
    951     return instr->representation().IsSmi() ?
    952         DefineAsRegister(new(zone()) LBitS(left, right)) :
    953         DefineAsRegister(new(zone()) LBitI(left, right));
    954   } else {
    955     return DoArithmeticT(instr->op(), instr);
    956   }
    957 }
    958 
    959 
    960 LInstruction* LChunkBuilder::DoBlockEntry(HBlockEntry* instr) {
    961   // V8 expects a label to be generated for each basic block.
    962   // This is used in some places like LAllocator::IsBlockBoundary
    963   // in lithium-allocator.cc
    964   return new(zone()) LLabel(instr->block());
    965 }
    966 
    967 
    968 LInstruction* LChunkBuilder::DoBoundsCheck(HBoundsCheck* instr) {
    969   if (!FLAG_debug_code && instr->skip_check()) return NULL;
    970   LOperand* index = UseRegisterOrConstantAtStart(instr->index());
    971   LOperand* length = !index->IsConstantOperand()
    972       ? UseRegisterOrConstantAtStart(instr->length())
    973       : UseRegisterAtStart(instr->length());
    974   LInstruction* result = new(zone()) LBoundsCheck(index, length);
    975   if (!FLAG_debug_code || !instr->skip_check()) {
    976     result = AssignEnvironment(result);
    977   }
    978   return result;
    979 }
    980 
    981 
    982 LInstruction* LChunkBuilder::DoBranch(HBranch* instr) {
    983   HValue* value = instr->value();
    984   Representation r = value->representation();
    985   HType type = value->type();
    986 
    987   if (r.IsInteger32() || r.IsSmi() || r.IsDouble()) {
    988     // These representations have simple checks that cannot deoptimize.
    989     return new(zone()) LBranch(UseRegister(value), NULL, NULL);
    990   } else {
    991     DCHECK(r.IsTagged());
    992     if (type.IsBoolean() || type.IsSmi() || type.IsJSArray() ||
    993         type.IsHeapNumber()) {
    994       // These types have simple checks that cannot deoptimize.
    995       return new(zone()) LBranch(UseRegister(value), NULL, NULL);
    996     }
    997 
    998     if (type.IsString()) {
    999       // This type cannot deoptimize, but needs a scratch register.
   1000       return new(zone()) LBranch(UseRegister(value), TempRegister(), NULL);
   1001     }
   1002 
   1003     ToBooleanStub::Types expected = instr->expected_input_types();
   1004     bool needs_temps = expected.NeedsMap() || expected.IsEmpty();
   1005     LOperand* temp1 = needs_temps ? TempRegister() : NULL;
   1006     LOperand* temp2 = needs_temps ? TempRegister() : NULL;
   1007 
   1008     if (expected.IsGeneric() || expected.IsEmpty()) {
   1009       // The generic case cannot deoptimize because it already supports every
   1010       // possible input type.
   1011       DCHECK(needs_temps);
   1012       return new(zone()) LBranch(UseRegister(value), temp1, temp2);
   1013     } else {
   1014       return AssignEnvironment(
   1015           new(zone()) LBranch(UseRegister(value), temp1, temp2));
   1016     }
   1017   }
   1018 }
   1019 
   1020 
   1021 LInstruction* LChunkBuilder::DoCallJSFunction(
   1022     HCallJSFunction* instr) {
   1023   LOperand* function = UseFixed(instr->function(), x1);
   1024 
   1025   LCallJSFunction* result = new(zone()) LCallJSFunction(function);
   1026 
   1027   return MarkAsCall(DefineFixed(result, x0), instr);
   1028 }
   1029 
   1030 
   1031 LInstruction* LChunkBuilder::DoCallWithDescriptor(
   1032     HCallWithDescriptor* instr) {
   1033   CallInterfaceDescriptor descriptor = instr->descriptor();
   1034 
   1035   LOperand* target = UseRegisterOrConstantAtStart(instr->target());
   1036   ZoneList<LOperand*> ops(instr->OperandCount(), zone());
   1037   ops.Add(target, zone());
   1038   for (int i = 1; i < instr->OperandCount(); i++) {
   1039     LOperand* op =
   1040         UseFixed(instr->OperandAt(i), descriptor.GetParameterRegister(i - 1));
   1041     ops.Add(op, zone());
   1042   }
   1043 
   1044   LCallWithDescriptor* result = new(zone()) LCallWithDescriptor(descriptor,
   1045                                                                 ops,
   1046                                                                 zone());
   1047   return MarkAsCall(DefineFixed(result, x0), instr);
   1048 }
   1049 
   1050 
   1051 LInstruction* LChunkBuilder::DoCallFunction(HCallFunction* instr) {
   1052   LOperand* context = UseFixed(instr->context(), cp);
   1053   LOperand* function = UseFixed(instr->function(), x1);
   1054   LCallFunction* call = new(zone()) LCallFunction(context, function);
   1055   return MarkAsCall(DefineFixed(call, x0), instr);
   1056 }
   1057 
   1058 
   1059 LInstruction* LChunkBuilder::DoCallNew(HCallNew* instr) {
   1060   LOperand* context = UseFixed(instr->context(), cp);
   1061   // The call to CallConstructStub will expect the constructor to be in x1.
   1062   LOperand* constructor = UseFixed(instr->constructor(), x1);
   1063   LCallNew* result = new(zone()) LCallNew(context, constructor);
   1064   return MarkAsCall(DefineFixed(result, x0), instr);
   1065 }
   1066 
   1067 
   1068 LInstruction* LChunkBuilder::DoCallNewArray(HCallNewArray* instr) {
   1069   LOperand* context = UseFixed(instr->context(), cp);
   1070   // The call to ArrayConstructCode will expect the constructor to be in x1.
   1071   LOperand* constructor = UseFixed(instr->constructor(), x1);
   1072   LCallNewArray* result = new(zone()) LCallNewArray(context, constructor);
   1073   return MarkAsCall(DefineFixed(result, x0), instr);
   1074 }
   1075 
   1076 
   1077 LInstruction* LChunkBuilder::DoCallRuntime(HCallRuntime* instr) {
   1078   LOperand* context = UseFixed(instr->context(), cp);
   1079   return MarkAsCall(DefineFixed(new(zone()) LCallRuntime(context), x0), instr);
   1080 }
   1081 
   1082 
   1083 LInstruction* LChunkBuilder::DoCallStub(HCallStub* instr) {
   1084   LOperand* context = UseFixed(instr->context(), cp);
   1085   return MarkAsCall(DefineFixed(new(zone()) LCallStub(context), x0), instr);
   1086 }
   1087 
   1088 
   1089 LInstruction* LChunkBuilder::DoCapturedObject(HCapturedObject* instr) {
   1090   instr->ReplayEnvironment(current_block_->last_environment());
   1091 
   1092   // There are no real uses of a captured object.
   1093   return NULL;
   1094 }
   1095 
   1096 
   1097 LInstruction* LChunkBuilder::DoChange(HChange* instr) {
   1098   Representation from = instr->from();
   1099   Representation to = instr->to();
   1100   HValue* val = instr->value();
   1101   if (from.IsSmi()) {
   1102     if (to.IsTagged()) {
   1103       LOperand* value = UseRegister(val);
   1104       return DefineSameAsFirst(new(zone()) LDummyUse(value));
   1105     }
   1106     from = Representation::Tagged();
   1107   }
   1108   if (from.IsTagged()) {
   1109     if (to.IsDouble()) {
   1110       LOperand* value = UseRegister(val);
   1111       LOperand* temp = TempRegister();
   1112       LInstruction* result =
   1113           DefineAsRegister(new(zone()) LNumberUntagD(value, temp));
   1114       if (!val->representation().IsSmi()) result = AssignEnvironment(result);
   1115       return result;
   1116     } else if (to.IsSmi()) {
   1117       LOperand* value = UseRegister(val);
   1118       if (val->type().IsSmi()) {
   1119         return DefineSameAsFirst(new(zone()) LDummyUse(value));
   1120       }
   1121       return AssignEnvironment(DefineSameAsFirst(new(zone()) LCheckSmi(value)));
   1122     } else {
   1123       DCHECK(to.IsInteger32());
   1124       if (val->type().IsSmi() || val->representation().IsSmi()) {
   1125         LOperand* value = UseRegisterAtStart(val);
   1126         return DefineAsRegister(new(zone()) LSmiUntag(value, false));
   1127       } else {
   1128         LOperand* value = UseRegister(val);
   1129         LOperand* temp1 = TempRegister();
   1130         LOperand* temp2 = instr->CanTruncateToInt32()
   1131             ? NULL : TempDoubleRegister();
   1132         LInstruction* result =
   1133             DefineAsRegister(new(zone()) LTaggedToI(value, temp1, temp2));
   1134         if (!val->representation().IsSmi()) result = AssignEnvironment(result);
   1135         return result;
   1136       }
   1137     }
   1138   } else if (from.IsDouble()) {
   1139     if (to.IsTagged()) {
   1140       info()->MarkAsDeferredCalling();
   1141       LOperand* value = UseRegister(val);
   1142       LOperand* temp1 = TempRegister();
   1143       LOperand* temp2 = TempRegister();
   1144       LNumberTagD* result = new(zone()) LNumberTagD(value, temp1, temp2);
   1145       return AssignPointerMap(DefineAsRegister(result));
   1146     } else {
   1147       DCHECK(to.IsSmi() || to.IsInteger32());
   1148       if (instr->CanTruncateToInt32()) {
   1149         LOperand* value = UseRegister(val);
   1150         return DefineAsRegister(new(zone()) LTruncateDoubleToIntOrSmi(value));
   1151       } else {
   1152         LOperand* value = UseRegister(val);
   1153         LDoubleToIntOrSmi* result = new(zone()) LDoubleToIntOrSmi(value);
   1154         return AssignEnvironment(DefineAsRegister(result));
   1155       }
   1156     }
   1157   } else if (from.IsInteger32()) {
   1158     info()->MarkAsDeferredCalling();
   1159     if (to.IsTagged()) {
   1160       if (val->CheckFlag(HInstruction::kUint32)) {
   1161         LOperand* value = UseRegister(val);
   1162         LNumberTagU* result =
   1163             new(zone()) LNumberTagU(value, TempRegister(), TempRegister());
   1164         return AssignPointerMap(DefineAsRegister(result));
   1165       } else {
   1166         STATIC_ASSERT((kMinInt == Smi::kMinValue) &&
   1167                       (kMaxInt == Smi::kMaxValue));
   1168         LOperand* value = UseRegisterAtStart(val);
   1169         return DefineAsRegister(new(zone()) LSmiTag(value));
   1170       }
   1171     } else if (to.IsSmi()) {
   1172       LOperand* value = UseRegisterAtStart(val);
   1173       LInstruction* result = DefineAsRegister(new(zone()) LSmiTag(value));
   1174       if (val->CheckFlag(HInstruction::kUint32)) {
   1175         result = AssignEnvironment(result);
   1176       }
   1177       return result;
   1178     } else {
   1179       DCHECK(to.IsDouble());
   1180       if (val->CheckFlag(HInstruction::kUint32)) {
   1181         return DefineAsRegister(
   1182             new(zone()) LUint32ToDouble(UseRegisterAtStart(val)));
   1183       } else {
   1184         return DefineAsRegister(
   1185             new(zone()) LInteger32ToDouble(UseRegisterAtStart(val)));
   1186       }
   1187     }
   1188   }
   1189   UNREACHABLE();
   1190   return NULL;
   1191 }
   1192 
   1193 
   1194 LInstruction* LChunkBuilder::DoCheckValue(HCheckValue* instr) {
   1195   LOperand* value = UseRegisterAtStart(instr->value());
   1196   return AssignEnvironment(new(zone()) LCheckValue(value));
   1197 }
   1198 
   1199 
   1200 LInstruction* LChunkBuilder::DoCheckInstanceType(HCheckInstanceType* instr) {
   1201   LOperand* value = UseRegisterAtStart(instr->value());
   1202   LOperand* temp = TempRegister();
   1203   LInstruction* result = new(zone()) LCheckInstanceType(value, temp);
   1204   return AssignEnvironment(result);
   1205 }
   1206 
   1207 
   1208 LInstruction* LChunkBuilder::DoCheckMaps(HCheckMaps* instr) {
   1209   if (instr->IsStabilityCheck()) return new(zone()) LCheckMaps;
   1210   LOperand* value = UseRegisterAtStart(instr->value());
   1211   LOperand* temp = TempRegister();
   1212   LInstruction* result = AssignEnvironment(new(zone()) LCheckMaps(value, temp));
   1213   if (instr->HasMigrationTarget()) {
   1214     info()->MarkAsDeferredCalling();
   1215     result = AssignPointerMap(result);
   1216   }
   1217   return result;
   1218 }
   1219 
   1220 
   1221 LInstruction* LChunkBuilder::DoCheckHeapObject(HCheckHeapObject* instr) {
   1222   LOperand* value = UseRegisterAtStart(instr->value());
   1223   LInstruction* result = new(zone()) LCheckNonSmi(value);
   1224   if (!instr->value()->type().IsHeapObject()) {
   1225     result = AssignEnvironment(result);
   1226   }
   1227   return result;
   1228 }
   1229 
   1230 
   1231 LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
   1232   LOperand* value = UseRegisterAtStart(instr->value());
   1233   return AssignEnvironment(new(zone()) LCheckSmi(value));
   1234 }
   1235 
   1236 
   1237 LInstruction* LChunkBuilder::DoClampToUint8(HClampToUint8* instr) {
   1238   HValue* value = instr->value();
   1239   Representation input_rep = value->representation();
   1240   LOperand* reg = UseRegister(value);
   1241   if (input_rep.IsDouble()) {
   1242     return DefineAsRegister(new(zone()) LClampDToUint8(reg));
   1243   } else if (input_rep.IsInteger32()) {
   1244     return DefineAsRegister(new(zone()) LClampIToUint8(reg));
   1245   } else {
   1246     DCHECK(input_rep.IsSmiOrTagged());
   1247     return AssignEnvironment(
   1248         DefineAsRegister(new(zone()) LClampTToUint8(reg,
   1249                                                     TempDoubleRegister())));
   1250   }
   1251 }
   1252 
   1253 
   1254 LInstruction* LChunkBuilder::DoClassOfTestAndBranch(
   1255     HClassOfTestAndBranch* instr) {
   1256   DCHECK(instr->value()->representation().IsTagged());
   1257   LOperand* value = UseRegisterAtStart(instr->value());
   1258   return new(zone()) LClassOfTestAndBranch(value,
   1259                                            TempRegister(),
   1260                                            TempRegister());
   1261 }
   1262 
   1263 
   1264 LInstruction* LChunkBuilder::DoCompareNumericAndBranch(
   1265     HCompareNumericAndBranch* instr) {
   1266   Representation r = instr->representation();
   1267   if (r.IsSmiOrInteger32()) {
   1268     DCHECK(instr->left()->representation().Equals(r));
   1269     DCHECK(instr->right()->representation().Equals(r));
   1270     LOperand* left = UseRegisterOrConstantAtStart(instr->left());
   1271     LOperand* right = UseRegisterOrConstantAtStart(instr->right());
   1272     return new(zone()) LCompareNumericAndBranch(left, right);
   1273   } else {
   1274     DCHECK(r.IsDouble());
   1275     DCHECK(instr->left()->representation().IsDouble());
   1276     DCHECK(instr->right()->representation().IsDouble());
   1277     if (instr->left()->IsConstant() && instr->right()->IsConstant()) {
   1278       LOperand* left = UseConstant(instr->left());
   1279       LOperand* right = UseConstant(instr->right());
   1280       return new(zone()) LCompareNumericAndBranch(left, right);
   1281     }
   1282     LOperand* left = UseRegisterAtStart(instr->left());
   1283     LOperand* right = UseRegisterAtStart(instr->right());
   1284     return new(zone()) LCompareNumericAndBranch(left, right);
   1285   }
   1286 }
   1287 
   1288 
   1289 LInstruction* LChunkBuilder::DoCompareGeneric(HCompareGeneric* instr) {
   1290   DCHECK(instr->left()->representation().IsTagged());
   1291   DCHECK(instr->right()->representation().IsTagged());
   1292   LOperand* context = UseFixed(instr->context(), cp);
   1293   LOperand* left = UseFixed(instr->left(), x1);
   1294   LOperand* right = UseFixed(instr->right(), x0);
   1295   LCmpT* result = new(zone()) LCmpT(context, left, right);
   1296   return MarkAsCall(DefineFixed(result, x0), instr);
   1297 }
   1298 
   1299 
   1300 LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
   1301     HCompareHoleAndBranch* instr) {
   1302   LOperand* value = UseRegister(instr->value());
   1303   if (instr->representation().IsTagged()) {
   1304     return new(zone()) LCmpHoleAndBranchT(value);
   1305   } else {
   1306     LOperand* temp = TempRegister();
   1307     return new(zone()) LCmpHoleAndBranchD(value, temp);
   1308   }
   1309 }
   1310 
   1311 
   1312 LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
   1313     HCompareObjectEqAndBranch* instr) {
   1314   LOperand* left = UseRegisterAtStart(instr->left());
   1315   LOperand* right = UseRegisterAtStart(instr->right());
   1316   return new(zone()) LCmpObjectEqAndBranch(left, right);
   1317 }
   1318 
   1319 
   1320 LInstruction* LChunkBuilder::DoCompareMap(HCompareMap* instr) {
   1321   DCHECK(instr->value()->representation().IsTagged());
   1322   LOperand* value = UseRegisterAtStart(instr->value());
   1323   LOperand* temp = TempRegister();
   1324   return new(zone()) LCmpMapAndBranch(value, temp);
   1325 }
   1326 
   1327 
   1328 LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
   1329   Representation r = instr->representation();
   1330   if (r.IsSmi()) {
   1331     return DefineAsRegister(new(zone()) LConstantS);
   1332   } else if (r.IsInteger32()) {
   1333     return DefineAsRegister(new(zone()) LConstantI);
   1334   } else if (r.IsDouble()) {
   1335     return DefineAsRegister(new(zone()) LConstantD);
   1336   } else if (r.IsExternal()) {
   1337     return DefineAsRegister(new(zone()) LConstantE);
   1338   } else if (r.IsTagged()) {
   1339     return DefineAsRegister(new(zone()) LConstantT);
   1340   } else {
   1341     UNREACHABLE();
   1342     return NULL;
   1343   }
   1344 }
   1345 
   1346 
   1347 LInstruction* LChunkBuilder::DoContext(HContext* instr) {
   1348   if (instr->HasNoUses()) return NULL;
   1349 
   1350   if (info()->IsStub()) {
   1351     return DefineFixed(new(zone()) LContext, cp);
   1352   }
   1353 
   1354   return DefineAsRegister(new(zone()) LContext);
   1355 }
   1356 
   1357 
   1358 LInstruction* LChunkBuilder::DoDateField(HDateField* instr) {
   1359   LOperand* object = UseFixed(instr->value(), x0);
   1360   LDateField* result = new(zone()) LDateField(object, instr->index());
   1361   return MarkAsCall(DefineFixed(result, x0), instr, CAN_DEOPTIMIZE_EAGERLY);
   1362 }
   1363 
   1364 
   1365 LInstruction* LChunkBuilder::DoDebugBreak(HDebugBreak* instr) {
   1366   return new(zone()) LDebugBreak();
   1367 }
   1368 
   1369 
   1370 LInstruction* LChunkBuilder::DoDeclareGlobals(HDeclareGlobals* instr) {
   1371   LOperand* context = UseFixed(instr->context(), cp);
   1372   return MarkAsCall(new(zone()) LDeclareGlobals(context), instr);
   1373 }
   1374 
   1375 
   1376 LInstruction* LChunkBuilder::DoDeoptimize(HDeoptimize* instr) {
   1377   return AssignEnvironment(new(zone()) LDeoptimize);
   1378 }
   1379 
   1380 
   1381 LInstruction* LChunkBuilder::DoDivByPowerOf2I(HDiv* instr) {
   1382   DCHECK(instr->representation().IsInteger32());
   1383   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1384   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1385   LOperand* dividend = UseRegister(instr->left());
   1386   int32_t divisor = instr->right()->GetInteger32Constant();
   1387   LInstruction* result = DefineAsRegister(new(zone()) LDivByPowerOf2I(
   1388           dividend, divisor));
   1389   if ((instr->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) ||
   1390       (instr->CheckFlag(HValue::kCanOverflow) && divisor == -1) ||
   1391       (!instr->CheckFlag(HInstruction::kAllUsesTruncatingToInt32) &&
   1392        divisor != 1 && divisor != -1)) {
   1393     result = AssignEnvironment(result);
   1394   }
   1395   return result;
   1396 }
   1397 
   1398 
   1399 LInstruction* LChunkBuilder::DoDivByConstI(HDiv* instr) {
   1400   DCHECK(instr->representation().IsInteger32());
   1401   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1402   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1403   LOperand* dividend = UseRegister(instr->left());
   1404   int32_t divisor = instr->right()->GetInteger32Constant();
   1405   LOperand* temp = instr->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)
   1406       ? NULL : TempRegister();
   1407   LInstruction* result = DefineAsRegister(new(zone()) LDivByConstI(
   1408           dividend, divisor, temp));
   1409   if (divisor == 0 ||
   1410       (instr->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) ||
   1411       !instr->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
   1412     result = AssignEnvironment(result);
   1413   }
   1414   return result;
   1415 }
   1416 
   1417 
   1418 LInstruction* LChunkBuilder::DoDivI(HBinaryOperation* instr) {
   1419   DCHECK(instr->representation().IsSmiOrInteger32());
   1420   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1421   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1422   LOperand* dividend = UseRegister(instr->left());
   1423   LOperand* divisor = UseRegister(instr->right());
   1424   LOperand* temp = instr->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)
   1425       ? NULL : TempRegister();
   1426   LInstruction* result =
   1427       DefineAsRegister(new(zone()) LDivI(dividend, divisor, temp));
   1428   if (!instr->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
   1429     result = AssignEnvironment(result);
   1430   }
   1431   return result;
   1432 }
   1433 
   1434 
   1435 LInstruction* LChunkBuilder::DoDiv(HDiv* instr) {
   1436   if (instr->representation().IsSmiOrInteger32()) {
   1437     if (instr->RightIsPowerOf2()) {
   1438       return DoDivByPowerOf2I(instr);
   1439     } else if (instr->right()->IsConstant()) {
   1440       return DoDivByConstI(instr);
   1441     } else {
   1442       return DoDivI(instr);
   1443     }
   1444   } else if (instr->representation().IsDouble()) {
   1445     return DoArithmeticD(Token::DIV, instr);
   1446   } else {
   1447     return DoArithmeticT(Token::DIV, instr);
   1448   }
   1449 }
   1450 
   1451 
   1452 LInstruction* LChunkBuilder::DoDummyUse(HDummyUse* instr) {
   1453   return DefineAsRegister(new(zone()) LDummyUse(UseAny(instr->value())));
   1454 }
   1455 
   1456 
   1457 LInstruction* LChunkBuilder::DoEnterInlined(HEnterInlined* instr) {
   1458   HEnvironment* outer = current_block_->last_environment();
   1459   outer->set_ast_id(instr->ReturnId());
   1460   HConstant* undefined = graph()->GetConstantUndefined();
   1461   HEnvironment* inner = outer->CopyForInlining(instr->closure(),
   1462                                                instr->arguments_count(),
   1463                                                instr->function(),
   1464                                                undefined,
   1465                                                instr->inlining_kind());
   1466   // Only replay binding of arguments object if it wasn't removed from graph.
   1467   if ((instr->arguments_var() != NULL) &&
   1468       instr->arguments_object()->IsLinked()) {
   1469     inner->Bind(instr->arguments_var(), instr->arguments_object());
   1470   }
   1471   inner->BindContext(instr->closure_context());
   1472   inner->set_entry(instr);
   1473   current_block_->UpdateEnvironment(inner);
   1474   chunk_->AddInlinedClosure(instr->closure());
   1475   return NULL;
   1476 }
   1477 
   1478 
   1479 LInstruction* LChunkBuilder::DoEnvironmentMarker(HEnvironmentMarker* instr) {
   1480   UNREACHABLE();
   1481   return NULL;
   1482 }
   1483 
   1484 
   1485 LInstruction* LChunkBuilder::DoForceRepresentation(
   1486     HForceRepresentation* instr) {
   1487   // All HForceRepresentation instructions should be eliminated in the
   1488   // representation change phase of Hydrogen.
   1489   UNREACHABLE();
   1490   return NULL;
   1491 }
   1492 
   1493 
   1494 LInstruction* LChunkBuilder::DoFunctionLiteral(HFunctionLiteral* instr) {
   1495   LOperand* context = UseFixed(instr->context(), cp);
   1496   return MarkAsCall(
   1497       DefineFixed(new(zone()) LFunctionLiteral(context), x0), instr);
   1498 }
   1499 
   1500 
   1501 LInstruction* LChunkBuilder::DoGetCachedArrayIndex(
   1502     HGetCachedArrayIndex* instr) {
   1503   DCHECK(instr->value()->representation().IsTagged());
   1504   LOperand* value = UseRegisterAtStart(instr->value());
   1505   return DefineAsRegister(new(zone()) LGetCachedArrayIndex(value));
   1506 }
   1507 
   1508 
   1509 LInstruction* LChunkBuilder::DoGoto(HGoto* instr) {
   1510   return new(zone()) LGoto(instr->FirstSuccessor());
   1511 }
   1512 
   1513 
   1514 LInstruction* LChunkBuilder::DoHasCachedArrayIndexAndBranch(
   1515     HHasCachedArrayIndexAndBranch* instr) {
   1516   DCHECK(instr->value()->representation().IsTagged());
   1517   return new(zone()) LHasCachedArrayIndexAndBranch(
   1518       UseRegisterAtStart(instr->value()), TempRegister());
   1519 }
   1520 
   1521 
   1522 LInstruction* LChunkBuilder::DoHasInstanceTypeAndBranch(
   1523     HHasInstanceTypeAndBranch* instr) {
   1524   DCHECK(instr->value()->representation().IsTagged());
   1525   LOperand* value = UseRegisterAtStart(instr->value());
   1526   return new(zone()) LHasInstanceTypeAndBranch(value, TempRegister());
   1527 }
   1528 
   1529 
   1530 LInstruction* LChunkBuilder::DoInnerAllocatedObject(
   1531     HInnerAllocatedObject* instr) {
   1532   LOperand* base_object = UseRegisterAtStart(instr->base_object());
   1533   LOperand* offset = UseRegisterOrConstantAtStart(instr->offset());
   1534   return DefineAsRegister(
   1535       new(zone()) LInnerAllocatedObject(base_object, offset));
   1536 }
   1537 
   1538 
   1539 LInstruction* LChunkBuilder::DoInstanceOf(HInstanceOf* instr) {
   1540   LOperand* context = UseFixed(instr->context(), cp);
   1541   LInstanceOf* result = new(zone()) LInstanceOf(
   1542       context,
   1543       UseFixed(instr->left(), InstanceofStub::left()),
   1544       UseFixed(instr->right(), InstanceofStub::right()));
   1545   return MarkAsCall(DefineFixed(result, x0), instr);
   1546 }
   1547 
   1548 
   1549 LInstruction* LChunkBuilder::DoInstanceOfKnownGlobal(
   1550     HInstanceOfKnownGlobal* instr) {
   1551   LInstanceOfKnownGlobal* result = new(zone()) LInstanceOfKnownGlobal(
   1552       UseFixed(instr->context(), cp),
   1553       UseFixed(instr->left(), InstanceofStub::left()));
   1554   return MarkAsCall(DefineFixed(result, x0), instr);
   1555 }
   1556 
   1557 
   1558 LInstruction* LChunkBuilder::DoTailCallThroughMegamorphicCache(
   1559     HTailCallThroughMegamorphicCache* instr) {
   1560   LOperand* context = UseFixed(instr->context(), cp);
   1561   LOperand* receiver_register =
   1562       UseFixed(instr->receiver(), LoadDescriptor::ReceiverRegister());
   1563   LOperand* name_register =
   1564       UseFixed(instr->name(), LoadDescriptor::NameRegister());
   1565   // Not marked as call. It can't deoptimize, and it never returns.
   1566   return new (zone()) LTailCallThroughMegamorphicCache(
   1567       context, receiver_register, name_register);
   1568 }
   1569 
   1570 
   1571 LInstruction* LChunkBuilder::DoInvokeFunction(HInvokeFunction* instr) {
   1572   LOperand* context = UseFixed(instr->context(), cp);
   1573   // The function is required (by MacroAssembler::InvokeFunction) to be in x1.
   1574   LOperand* function = UseFixed(instr->function(), x1);
   1575   LInvokeFunction* result = new(zone()) LInvokeFunction(context, function);
   1576   return MarkAsCall(DefineFixed(result, x0), instr, CANNOT_DEOPTIMIZE_EAGERLY);
   1577 }
   1578 
   1579 
   1580 LInstruction* LChunkBuilder::DoIsConstructCallAndBranch(
   1581     HIsConstructCallAndBranch* instr) {
   1582   return new(zone()) LIsConstructCallAndBranch(TempRegister(), TempRegister());
   1583 }
   1584 
   1585 
   1586 LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
   1587     HCompareMinusZeroAndBranch* instr) {
   1588   LOperand* value = UseRegister(instr->value());
   1589   LOperand* scratch = TempRegister();
   1590   return new(zone()) LCompareMinusZeroAndBranch(value, scratch);
   1591 }
   1592 
   1593 
   1594 LInstruction* LChunkBuilder::DoIsObjectAndBranch(HIsObjectAndBranch* instr) {
   1595   DCHECK(instr->value()->representation().IsTagged());
   1596   LOperand* value = UseRegisterAtStart(instr->value());
   1597   LOperand* temp1 = TempRegister();
   1598   LOperand* temp2 = TempRegister();
   1599   return new(zone()) LIsObjectAndBranch(value, temp1, temp2);
   1600 }
   1601 
   1602 
   1603 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   1604   DCHECK(instr->value()->representation().IsTagged());
   1605   LOperand* value = UseRegisterAtStart(instr->value());
   1606   LOperand* temp = TempRegister();
   1607   return new(zone()) LIsStringAndBranch(value, temp);
   1608 }
   1609 
   1610 
   1611 LInstruction* LChunkBuilder::DoIsSmiAndBranch(HIsSmiAndBranch* instr) {
   1612   DCHECK(instr->value()->representation().IsTagged());
   1613   return new(zone()) LIsSmiAndBranch(UseRegisterAtStart(instr->value()));
   1614 }
   1615 
   1616 
   1617 LInstruction* LChunkBuilder::DoIsUndetectableAndBranch(
   1618     HIsUndetectableAndBranch* instr) {
   1619   DCHECK(instr->value()->representation().IsTagged());
   1620   LOperand* value = UseRegisterAtStart(instr->value());
   1621   return new(zone()) LIsUndetectableAndBranch(value, TempRegister());
   1622 }
   1623 
   1624 
   1625 LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
   1626   LInstruction* pop = NULL;
   1627   HEnvironment* env = current_block_->last_environment();
   1628 
   1629   if (env->entry()->arguments_pushed()) {
   1630     int argument_count = env->arguments_environment()->parameter_count();
   1631     pop = new(zone()) LDrop(argument_count);
   1632     DCHECK(instr->argument_delta() == -argument_count);
   1633   }
   1634 
   1635   HEnvironment* outer =
   1636       current_block_->last_environment()->DiscardInlined(false);
   1637   current_block_->UpdateEnvironment(outer);
   1638 
   1639   return pop;
   1640 }
   1641 
   1642 
   1643 LInstruction* LChunkBuilder::DoLoadContextSlot(HLoadContextSlot* instr) {
   1644   LOperand* context = UseRegisterAtStart(instr->value());
   1645   LInstruction* result =
   1646       DefineAsRegister(new(zone()) LLoadContextSlot(context));
   1647   if (instr->RequiresHoleCheck() && instr->DeoptimizesOnHole()) {
   1648     result = AssignEnvironment(result);
   1649   }
   1650   return result;
   1651 }
   1652 
   1653 
   1654 LInstruction* LChunkBuilder::DoLoadFunctionPrototype(
   1655     HLoadFunctionPrototype* instr) {
   1656   LOperand* function = UseRegister(instr->function());
   1657   LOperand* temp = TempRegister();
   1658   return AssignEnvironment(DefineAsRegister(
   1659       new(zone()) LLoadFunctionPrototype(function, temp)));
   1660 }
   1661 
   1662 
   1663 LInstruction* LChunkBuilder::DoLoadGlobalCell(HLoadGlobalCell* instr) {
   1664   LLoadGlobalCell* result = new(zone()) LLoadGlobalCell();
   1665   return instr->RequiresHoleCheck()
   1666       ? AssignEnvironment(DefineAsRegister(result))
   1667       : DefineAsRegister(result);
   1668 }
   1669 
   1670 
   1671 LInstruction* LChunkBuilder::DoLoadGlobalGeneric(HLoadGlobalGeneric* instr) {
   1672   LOperand* context = UseFixed(instr->context(), cp);
   1673   LOperand* global_object =
   1674       UseFixed(instr->global_object(), LoadDescriptor::ReceiverRegister());
   1675   LOperand* vector = NULL;
   1676   if (FLAG_vector_ics) {
   1677     vector = FixedTemp(VectorLoadICDescriptor::VectorRegister());
   1678   }
   1679 
   1680   LLoadGlobalGeneric* result =
   1681       new(zone()) LLoadGlobalGeneric(context, global_object, vector);
   1682   return MarkAsCall(DefineFixed(result, x0), instr);
   1683 }
   1684 
   1685 
   1686 LInstruction* LChunkBuilder::DoLoadKeyed(HLoadKeyed* instr) {
   1687   DCHECK(instr->key()->representation().IsSmiOrInteger32());
   1688   ElementsKind elements_kind = instr->elements_kind();
   1689   LOperand* elements = UseRegister(instr->elements());
   1690   LOperand* key = UseRegisterOrConstant(instr->key());
   1691 
   1692   if (!instr->is_typed_elements()) {
   1693     if (instr->representation().IsDouble()) {
   1694       LOperand* temp = (!instr->key()->IsConstant() ||
   1695                         instr->RequiresHoleCheck())
   1696              ? TempRegister()
   1697              : NULL;
   1698 
   1699       LLoadKeyedFixedDouble* result =
   1700           new(zone()) LLoadKeyedFixedDouble(elements, key, temp);
   1701       return instr->RequiresHoleCheck()
   1702           ? AssignEnvironment(DefineAsRegister(result))
   1703           : DefineAsRegister(result);
   1704     } else {
   1705       DCHECK(instr->representation().IsSmiOrTagged() ||
   1706              instr->representation().IsInteger32());
   1707       LOperand* temp = instr->key()->IsConstant() ? NULL : TempRegister();
   1708       LLoadKeyedFixed* result =
   1709           new(zone()) LLoadKeyedFixed(elements, key, temp);
   1710       return instr->RequiresHoleCheck()
   1711           ? AssignEnvironment(DefineAsRegister(result))
   1712           : DefineAsRegister(result);
   1713     }
   1714   } else {
   1715     DCHECK((instr->representation().IsInteger32() &&
   1716             !IsDoubleOrFloatElementsKind(instr->elements_kind())) ||
   1717            (instr->representation().IsDouble() &&
   1718             IsDoubleOrFloatElementsKind(instr->elements_kind())));
   1719 
   1720     LOperand* temp = instr->key()->IsConstant() ? NULL : TempRegister();
   1721     LInstruction* result = DefineAsRegister(
   1722         new(zone()) LLoadKeyedExternal(elements, key, temp));
   1723     if ((elements_kind == EXTERNAL_UINT32_ELEMENTS ||
   1724          elements_kind == UINT32_ELEMENTS) &&
   1725         !instr->CheckFlag(HInstruction::kUint32)) {
   1726       result = AssignEnvironment(result);
   1727     }
   1728     return result;
   1729   }
   1730 }
   1731 
   1732 
   1733 LInstruction* LChunkBuilder::DoLoadKeyedGeneric(HLoadKeyedGeneric* instr) {
   1734   LOperand* context = UseFixed(instr->context(), cp);
   1735   LOperand* object =
   1736       UseFixed(instr->object(), LoadDescriptor::ReceiverRegister());
   1737   LOperand* key = UseFixed(instr->key(), LoadDescriptor::NameRegister());
   1738   LOperand* vector = NULL;
   1739   if (FLAG_vector_ics) {
   1740     vector = FixedTemp(VectorLoadICDescriptor::VectorRegister());
   1741   }
   1742 
   1743   LInstruction* result =
   1744       DefineFixed(new(zone()) LLoadKeyedGeneric(context, object, key, vector),
   1745                   x0);
   1746   return MarkAsCall(result, instr);
   1747 }
   1748 
   1749 
   1750 LInstruction* LChunkBuilder::DoLoadNamedField(HLoadNamedField* instr) {
   1751   LOperand* object = UseRegisterAtStart(instr->object());
   1752   return DefineAsRegister(new(zone()) LLoadNamedField(object));
   1753 }
   1754 
   1755 
   1756 LInstruction* LChunkBuilder::DoLoadNamedGeneric(HLoadNamedGeneric* instr) {
   1757   LOperand* context = UseFixed(instr->context(), cp);
   1758   LOperand* object =
   1759       UseFixed(instr->object(), LoadDescriptor::ReceiverRegister());
   1760   LOperand* vector = NULL;
   1761   if (FLAG_vector_ics) {
   1762     vector = FixedTemp(VectorLoadICDescriptor::VectorRegister());
   1763   }
   1764 
   1765   LInstruction* result =
   1766       DefineFixed(new(zone()) LLoadNamedGeneric(context, object, vector), x0);
   1767   return MarkAsCall(result, instr);
   1768 }
   1769 
   1770 
   1771 LInstruction* LChunkBuilder::DoLoadRoot(HLoadRoot* instr) {
   1772   return DefineAsRegister(new(zone()) LLoadRoot);
   1773 }
   1774 
   1775 
   1776 LInstruction* LChunkBuilder::DoMapEnumLength(HMapEnumLength* instr) {
   1777   LOperand* map = UseRegisterAtStart(instr->value());
   1778   return DefineAsRegister(new(zone()) LMapEnumLength(map));
   1779 }
   1780 
   1781 
   1782 LInstruction* LChunkBuilder::DoFlooringDivByPowerOf2I(HMathFloorOfDiv* instr) {
   1783   DCHECK(instr->representation().IsInteger32());
   1784   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1785   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1786   LOperand* dividend = UseRegisterAtStart(instr->left());
   1787   int32_t divisor = instr->right()->GetInteger32Constant();
   1788   LInstruction* result = DefineAsRegister(new(zone()) LFlooringDivByPowerOf2I(
   1789           dividend, divisor));
   1790   if ((instr->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) ||
   1791       (instr->CheckFlag(HValue::kLeftCanBeMinInt) && divisor == -1)) {
   1792     result = AssignEnvironment(result);
   1793   }
   1794   return result;
   1795 }
   1796 
   1797 
   1798 LInstruction* LChunkBuilder::DoFlooringDivByConstI(HMathFloorOfDiv* instr) {
   1799   DCHECK(instr->representation().IsInteger32());
   1800   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1801   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1802   LOperand* dividend = UseRegister(instr->left());
   1803   int32_t divisor = instr->right()->GetInteger32Constant();
   1804   LOperand* temp =
   1805       ((divisor > 0 && !instr->CheckFlag(HValue::kLeftCanBeNegative)) ||
   1806        (divisor < 0 && !instr->CheckFlag(HValue::kLeftCanBePositive))) ?
   1807       NULL : TempRegister();
   1808   LInstruction* result = DefineAsRegister(
   1809       new(zone()) LFlooringDivByConstI(dividend, divisor, temp));
   1810   if (divisor == 0 ||
   1811       (instr->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0)) {
   1812     result = AssignEnvironment(result);
   1813   }
   1814   return result;
   1815 }
   1816 
   1817 
   1818 LInstruction* LChunkBuilder::DoFlooringDivI(HMathFloorOfDiv* instr) {
   1819   LOperand* dividend = UseRegister(instr->left());
   1820   LOperand* divisor = UseRegister(instr->right());
   1821   LOperand* remainder = TempRegister();
   1822   LInstruction* result =
   1823       DefineAsRegister(new(zone()) LFlooringDivI(dividend, divisor, remainder));
   1824   return AssignEnvironment(result);
   1825 }
   1826 
   1827 
   1828 LInstruction* LChunkBuilder::DoMathFloorOfDiv(HMathFloorOfDiv* instr) {
   1829   if (instr->RightIsPowerOf2()) {
   1830     return DoFlooringDivByPowerOf2I(instr);
   1831   } else if (instr->right()->IsConstant()) {
   1832     return DoFlooringDivByConstI(instr);
   1833   } else {
   1834     return DoFlooringDivI(instr);
   1835   }
   1836 }
   1837 
   1838 
   1839 LInstruction* LChunkBuilder::DoMathMinMax(HMathMinMax* instr) {
   1840   LOperand* left = NULL;
   1841   LOperand* right = NULL;
   1842   if (instr->representation().IsSmiOrInteger32()) {
   1843     DCHECK(instr->left()->representation().Equals(instr->representation()));
   1844     DCHECK(instr->right()->representation().Equals(instr->representation()));
   1845     left = UseRegisterAtStart(instr->BetterLeftOperand());
   1846     right = UseRegisterOrConstantAtStart(instr->BetterRightOperand());
   1847   } else {
   1848     DCHECK(instr->representation().IsDouble());
   1849     DCHECK(instr->left()->representation().IsDouble());
   1850     DCHECK(instr->right()->representation().IsDouble());
   1851     left = UseRegisterAtStart(instr->left());
   1852     right = UseRegisterAtStart(instr->right());
   1853   }
   1854   return DefineAsRegister(new(zone()) LMathMinMax(left, right));
   1855 }
   1856 
   1857 
   1858 LInstruction* LChunkBuilder::DoModByPowerOf2I(HMod* instr) {
   1859   DCHECK(instr->representation().IsInteger32());
   1860   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1861   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1862   LOperand* dividend = UseRegisterAtStart(instr->left());
   1863   int32_t divisor = instr->right()->GetInteger32Constant();
   1864   LInstruction* result = DefineSameAsFirst(new(zone()) LModByPowerOf2I(
   1865           dividend, divisor));
   1866   if (instr->CheckFlag(HValue::kLeftCanBeNegative) &&
   1867       instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1868     result = AssignEnvironment(result);
   1869   }
   1870   return result;
   1871 }
   1872 
   1873 
   1874 LInstruction* LChunkBuilder::DoModByConstI(HMod* instr) {
   1875   DCHECK(instr->representation().IsInteger32());
   1876   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1877   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1878   LOperand* dividend = UseRegister(instr->left());
   1879   int32_t divisor = instr->right()->GetInteger32Constant();
   1880   LOperand* temp = TempRegister();
   1881   LInstruction* result = DefineAsRegister(new(zone()) LModByConstI(
   1882           dividend, divisor, temp));
   1883   if (divisor == 0 || instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1884     result = AssignEnvironment(result);
   1885   }
   1886   return result;
   1887 }
   1888 
   1889 
   1890 LInstruction* LChunkBuilder::DoModI(HMod* instr) {
   1891   DCHECK(instr->representation().IsSmiOrInteger32());
   1892   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1893   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1894   LOperand* dividend = UseRegister(instr->left());
   1895   LOperand* divisor = UseRegister(instr->right());
   1896   LInstruction* result = DefineAsRegister(new(zone()) LModI(dividend, divisor));
   1897   if (instr->CheckFlag(HValue::kCanBeDivByZero) ||
   1898       instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1899     result = AssignEnvironment(result);
   1900   }
   1901   return result;
   1902 }
   1903 
   1904 
   1905 LInstruction* LChunkBuilder::DoMod(HMod* instr) {
   1906   if (instr->representation().IsSmiOrInteger32()) {
   1907     if (instr->RightIsPowerOf2()) {
   1908       return DoModByPowerOf2I(instr);
   1909     } else if (instr->right()->IsConstant()) {
   1910       return DoModByConstI(instr);
   1911     } else {
   1912       return DoModI(instr);
   1913     }
   1914   } else if (instr->representation().IsDouble()) {
   1915     return DoArithmeticD(Token::MOD, instr);
   1916   } else {
   1917     return DoArithmeticT(Token::MOD, instr);
   1918   }
   1919 }
   1920 
   1921 
   1922 LInstruction* LChunkBuilder::DoMul(HMul* instr) {
   1923   if (instr->representation().IsSmiOrInteger32()) {
   1924     DCHECK(instr->left()->representation().Equals(instr->representation()));
   1925     DCHECK(instr->right()->representation().Equals(instr->representation()));
   1926 
   1927     bool can_overflow = instr->CheckFlag(HValue::kCanOverflow);
   1928     bool bailout_on_minus_zero = instr->CheckFlag(HValue::kBailoutOnMinusZero);
   1929 
   1930     HValue* least_const = instr->BetterLeftOperand();
   1931     HValue* most_const = instr->BetterRightOperand();
   1932 
   1933     // LMulConstI can handle a subset of constants:
   1934     //  With support for overflow detection:
   1935     //    -1, 0, 1, 2
   1936     //    2^n, -(2^n)
   1937     //  Without support for overflow detection:
   1938     //    2^n + 1, -(2^n - 1)
   1939     if (most_const->IsConstant()) {
   1940       int32_t constant = HConstant::cast(most_const)->Integer32Value();
   1941       bool small_constant = (constant >= -1) && (constant <= 2);
   1942       bool end_range_constant = (constant <= -kMaxInt) || (constant == kMaxInt);
   1943       int32_t constant_abs = Abs(constant);
   1944 
   1945       if (!end_range_constant &&
   1946           (small_constant || (base::bits::IsPowerOfTwo32(constant_abs)) ||
   1947            (!can_overflow && (base::bits::IsPowerOfTwo32(constant_abs + 1) ||
   1948                               base::bits::IsPowerOfTwo32(constant_abs - 1))))) {
   1949         LConstantOperand* right = UseConstant(most_const);
   1950         bool need_register =
   1951             base::bits::IsPowerOfTwo32(constant_abs) && !small_constant;
   1952         LOperand* left = need_register ? UseRegister(least_const)
   1953                                        : UseRegisterAtStart(least_const);
   1954         LInstruction* result =
   1955             DefineAsRegister(new(zone()) LMulConstIS(left, right));
   1956         if ((bailout_on_minus_zero && constant <= 0) || can_overflow) {
   1957           result = AssignEnvironment(result);
   1958         }
   1959         return result;
   1960       }
   1961     }
   1962 
   1963     // LMulI/S can handle all cases, but it requires that a register is
   1964     // allocated for the second operand.
   1965     LOperand* left = UseRegisterAtStart(least_const);
   1966     LOperand* right = UseRegisterAtStart(most_const);
   1967     LInstruction* result = instr->representation().IsSmi()
   1968         ? DefineAsRegister(new(zone()) LMulS(left, right))
   1969         : DefineAsRegister(new(zone()) LMulI(left, right));
   1970     if ((bailout_on_minus_zero && least_const != most_const) || can_overflow) {
   1971       result = AssignEnvironment(result);
   1972     }
   1973     return result;
   1974   } else if (instr->representation().IsDouble()) {
   1975     return DoArithmeticD(Token::MUL, instr);
   1976   } else {
   1977     return DoArithmeticT(Token::MUL, instr);
   1978   }
   1979 }
   1980 
   1981 
   1982 LInstruction* LChunkBuilder::DoOsrEntry(HOsrEntry* instr) {
   1983   DCHECK(argument_count_ == 0);
   1984   allocator_->MarkAsOsrEntry();
   1985   current_block_->last_environment()->set_ast_id(instr->ast_id());
   1986   return AssignEnvironment(new(zone()) LOsrEntry);
   1987 }
   1988 
   1989 
   1990 LInstruction* LChunkBuilder::DoParameter(HParameter* instr) {
   1991   LParameter* result = new(zone()) LParameter;
   1992   if (instr->kind() == HParameter::STACK_PARAMETER) {
   1993     int spill_index = chunk_->GetParameterStackSlot(instr->index());
   1994     return DefineAsSpilled(result, spill_index);
   1995   } else {
   1996     DCHECK(info()->IsStub());
   1997     CallInterfaceDescriptor descriptor =
   1998         info()->code_stub()->GetCallInterfaceDescriptor();
   1999     int index = static_cast<int>(instr->index());
   2000     Register reg = descriptor.GetEnvironmentParameterRegister(index);
   2001     return DefineFixed(result, reg);
   2002   }
   2003 }
   2004 
   2005 
   2006 LInstruction* LChunkBuilder::DoPower(HPower* instr) {
   2007   DCHECK(instr->representation().IsDouble());
   2008   // We call a C function for double power. It can't trigger a GC.
   2009   // We need to use fixed result register for the call.
   2010   Representation exponent_type = instr->right()->representation();
   2011   DCHECK(instr->left()->representation().IsDouble());
   2012   LOperand* left = UseFixedDouble(instr->left(), d0);
   2013   LOperand* right;
   2014   if (exponent_type.IsInteger32()) {
   2015     right = UseFixed(instr->right(), MathPowIntegerDescriptor::exponent());
   2016   } else if (exponent_type.IsDouble()) {
   2017     right = UseFixedDouble(instr->right(), d1);
   2018   } else {
   2019     right = UseFixed(instr->right(), MathPowTaggedDescriptor::exponent());
   2020   }
   2021   LPower* result = new(zone()) LPower(left, right);
   2022   return MarkAsCall(DefineFixedDouble(result, d0),
   2023                     instr,
   2024                     CAN_DEOPTIMIZE_EAGERLY);
   2025 }
   2026 
   2027 
   2028 LInstruction* LChunkBuilder::DoPushArguments(HPushArguments* instr) {
   2029   int argc = instr->OperandCount();
   2030   AddInstruction(new(zone()) LPreparePushArguments(argc), instr);
   2031 
   2032   LPushArguments* push_args = new(zone()) LPushArguments(zone());
   2033 
   2034   for (int i = 0; i < argc; ++i) {
   2035     if (push_args->ShouldSplitPush()) {
   2036       AddInstruction(push_args, instr);
   2037       push_args = new(zone()) LPushArguments(zone());
   2038     }
   2039     push_args->AddArgument(UseRegister(instr->argument(i)));
   2040   }
   2041 
   2042   return push_args;
   2043 }
   2044 
   2045 
   2046 LInstruction* LChunkBuilder::DoRegExpLiteral(HRegExpLiteral* instr) {
   2047   LOperand* context = UseFixed(instr->context(), cp);
   2048   return MarkAsCall(
   2049       DefineFixed(new(zone()) LRegExpLiteral(context), x0), instr);
   2050 }
   2051 
   2052 
   2053 LInstruction* LChunkBuilder::DoDoubleBits(HDoubleBits* instr) {
   2054   HValue* value = instr->value();
   2055   DCHECK(value->representation().IsDouble());
   2056   return DefineAsRegister(new(zone()) LDoubleBits(UseRegister(value)));
   2057 }
   2058 
   2059 
   2060 LInstruction* LChunkBuilder::DoConstructDouble(HConstructDouble* instr) {
   2061   LOperand* lo = UseRegisterAndClobber(instr->lo());
   2062   LOperand* hi = UseRegister(instr->hi());
   2063   return DefineAsRegister(new(zone()) LConstructDouble(hi, lo));
   2064 }
   2065 
   2066 
   2067 LInstruction* LChunkBuilder::DoReturn(HReturn* instr) {
   2068   LOperand* context = info()->IsStub()
   2069       ? UseFixed(instr->context(), cp)
   2070       : NULL;
   2071   LOperand* parameter_count = UseRegisterOrConstant(instr->parameter_count());
   2072   return new(zone()) LReturn(UseFixed(instr->value(), x0), context,
   2073                              parameter_count);
   2074 }
   2075 
   2076 
   2077 LInstruction* LChunkBuilder::DoSeqStringGetChar(HSeqStringGetChar* instr) {
   2078   LOperand* string = UseRegisterAtStart(instr->string());
   2079   LOperand* index = UseRegisterOrConstantAtStart(instr->index());
   2080   LOperand* temp = TempRegister();
   2081   LSeqStringGetChar* result =
   2082       new(zone()) LSeqStringGetChar(string, index, temp);
   2083   return DefineAsRegister(result);
   2084 }
   2085 
   2086 
   2087 LInstruction* LChunkBuilder::DoSeqStringSetChar(HSeqStringSetChar* instr) {
   2088   LOperand* string = UseRegister(instr->string());
   2089   LOperand* index = FLAG_debug_code
   2090       ? UseRegister(instr->index())
   2091       : UseRegisterOrConstant(instr->index());
   2092   LOperand* value = UseRegister(instr->value());
   2093   LOperand* context = FLAG_debug_code ? UseFixed(instr->context(), cp) : NULL;
   2094   LOperand* temp = TempRegister();
   2095   LSeqStringSetChar* result =
   2096       new(zone()) LSeqStringSetChar(context, string, index, value, temp);
   2097   return DefineAsRegister(result);
   2098 }
   2099 
   2100 
   2101 HBitwiseBinaryOperation* LChunkBuilder::CanTransformToShiftedOp(HValue* val,
   2102                                                                 HValue** left) {
   2103   if (!val->representation().IsInteger32()) return NULL;
   2104   if (!(val->IsBitwise() || val->IsAdd() || val->IsSub())) return NULL;
   2105 
   2106   HBinaryOperation* hinstr = HBinaryOperation::cast(val);
   2107   HValue* hleft = hinstr->left();
   2108   HValue* hright = hinstr->right();
   2109   DCHECK(hleft->representation().Equals(hinstr->representation()));
   2110   DCHECK(hright->representation().Equals(hinstr->representation()));
   2111 
   2112   if ((hright->IsConstant() &&
   2113        LikelyFitsImmField(hinstr, HConstant::cast(hright)->Integer32Value())) ||
   2114       (hinstr->IsCommutative() && hleft->IsConstant() &&
   2115        LikelyFitsImmField(hinstr, HConstant::cast(hleft)->Integer32Value()))) {
   2116     // The constant operand will likely fit in the immediate field. We are
   2117     // better off with
   2118     //     lsl x8, x9, #imm
   2119     //     add x0, x8, #imm2
   2120     // than with
   2121     //     mov x16, #imm2
   2122     //     add x0, x16, x9 LSL #imm
   2123     return NULL;
   2124   }
   2125 
   2126   HBitwiseBinaryOperation* shift = NULL;
   2127   // TODO(aleram): We will miss situations where a shift operation is used by
   2128   // different instructions both as a left and right operands.
   2129   if (hright->IsBitwiseBinaryShift() &&
   2130       HBitwiseBinaryOperation::cast(hright)->right()->IsConstant()) {
   2131     shift = HBitwiseBinaryOperation::cast(hright);
   2132     if (left != NULL) {
   2133       *left = hleft;
   2134     }
   2135   } else if (hinstr->IsCommutative() &&
   2136              hleft->IsBitwiseBinaryShift() &&
   2137              HBitwiseBinaryOperation::cast(hleft)->right()->IsConstant()) {
   2138     shift = HBitwiseBinaryOperation::cast(hleft);
   2139     if (left != NULL) {
   2140       *left = hright;
   2141     }
   2142   } else {
   2143     return NULL;
   2144   }
   2145 
   2146   if ((JSShiftAmountFromHConstant(shift->right()) == 0) && shift->IsShr()) {
   2147     // Shifts right by zero can deoptimize.
   2148     return NULL;
   2149   }
   2150 
   2151   return shift;
   2152 }
   2153 
   2154 
   2155 bool LChunkBuilder::ShiftCanBeOptimizedAway(HBitwiseBinaryOperation* shift) {
   2156   if (!shift->representation().IsInteger32()) {
   2157     return false;
   2158   }
   2159   for (HUseIterator it(shift->uses()); !it.Done(); it.Advance()) {
   2160     if (shift != CanTransformToShiftedOp(it.value())) {
   2161       return false;
   2162     }
   2163   }
   2164   return true;
   2165 }
   2166 
   2167 
   2168 LInstruction* LChunkBuilder::TryDoOpWithShiftedRightOperand(
   2169     HBinaryOperation* instr) {
   2170   HValue* left;
   2171   HBitwiseBinaryOperation* shift = CanTransformToShiftedOp(instr, &left);
   2172 
   2173   if ((shift != NULL) && ShiftCanBeOptimizedAway(shift)) {
   2174     return DoShiftedBinaryOp(instr, left, shift);
   2175   }
   2176   return NULL;
   2177 }
   2178 
   2179 
   2180 LInstruction* LChunkBuilder::DoShiftedBinaryOp(
   2181     HBinaryOperation* hinstr, HValue* hleft, HBitwiseBinaryOperation* hshift) {
   2182   DCHECK(hshift->IsBitwiseBinaryShift());
   2183   DCHECK(!hshift->IsShr() || (JSShiftAmountFromHConstant(hshift->right()) > 0));
   2184 
   2185   LTemplateResultInstruction<1>* res;
   2186   LOperand* left = UseRegisterAtStart(hleft);
   2187   LOperand* right = UseRegisterAtStart(hshift->left());
   2188   LOperand* shift_amount = UseConstant(hshift->right());
   2189   Shift shift_op;
   2190   switch (hshift->opcode()) {
   2191     case HValue::kShl: shift_op = LSL; break;
   2192     case HValue::kShr: shift_op = LSR; break;
   2193     case HValue::kSar: shift_op = ASR; break;
   2194     default: UNREACHABLE(); shift_op = NO_SHIFT;
   2195   }
   2196 
   2197   if (hinstr->IsBitwise()) {
   2198     res = new(zone()) LBitI(left, right, shift_op, shift_amount);
   2199   } else if (hinstr->IsAdd()) {
   2200     res = new(zone()) LAddI(left, right, shift_op, shift_amount);
   2201   } else {
   2202     DCHECK(hinstr->IsSub());
   2203     res = new(zone()) LSubI(left, right, shift_op, shift_amount);
   2204   }
   2205   if (hinstr->CheckFlag(HValue::kCanOverflow)) {
   2206     AssignEnvironment(res);
   2207   }
   2208   return DefineAsRegister(res);
   2209 }
   2210 
   2211 
   2212 LInstruction* LChunkBuilder::DoShift(Token::Value op,
   2213                                      HBitwiseBinaryOperation* instr) {
   2214   if (instr->representation().IsTagged()) {
   2215     return DoArithmeticT(op, instr);
   2216   }
   2217 
   2218   DCHECK(instr->representation().IsSmiOrInteger32());
   2219   DCHECK(instr->left()->representation().Equals(instr->representation()));
   2220   DCHECK(instr->right()->representation().Equals(instr->representation()));
   2221 
   2222   if (ShiftCanBeOptimizedAway(instr)) {
   2223     return NULL;
   2224   }
   2225 
   2226   LOperand* left = instr->representation().IsSmi()
   2227       ? UseRegister(instr->left())
   2228       : UseRegisterAtStart(instr->left());
   2229   LOperand* right = UseRegisterOrConstantAtStart(instr->right());
   2230 
   2231   // The only shift that can deoptimize is `left >>> 0`, where left is negative.
   2232   // In these cases, the result is a uint32 that is too large for an int32.
   2233   bool right_can_be_zero = !instr->right()->IsConstant() ||
   2234                            (JSShiftAmountFromHConstant(instr->right()) == 0);
   2235   bool can_deopt = false;
   2236   if ((op == Token::SHR) && right_can_be_zero) {
   2237     if (FLAG_opt_safe_uint32_operations) {
   2238       can_deopt = !instr->CheckFlag(HInstruction::kUint32);
   2239     } else {
   2240       can_deopt = !instr->CheckUsesForFlag(HValue::kTruncatingToInt32);
   2241     }
   2242   }
   2243 
   2244   LInstruction* result;
   2245   if (instr->representation().IsInteger32()) {
   2246     result = DefineAsRegister(new (zone()) LShiftI(op, left, right, can_deopt));
   2247   } else {
   2248     DCHECK(instr->representation().IsSmi());
   2249     result = DefineAsRegister(new (zone()) LShiftS(op, left, right, can_deopt));
   2250   }
   2251 
   2252   return can_deopt ? AssignEnvironment(result) : result;
   2253 }
   2254 
   2255 
   2256 LInstruction* LChunkBuilder::DoRor(HRor* instr) {
   2257   return DoShift(Token::ROR, instr);
   2258 }
   2259 
   2260 
   2261 LInstruction* LChunkBuilder::DoSar(HSar* instr) {
   2262   return DoShift(Token::SAR, instr);
   2263 }
   2264 
   2265 
   2266 LInstruction* LChunkBuilder::DoShl(HShl* instr) {
   2267   return DoShift(Token::SHL, instr);
   2268 }
   2269 
   2270 
   2271 LInstruction* LChunkBuilder::DoShr(HShr* instr) {
   2272   return DoShift(Token::SHR, instr);
   2273 }
   2274 
   2275 
   2276 LInstruction* LChunkBuilder::DoSimulate(HSimulate* instr) {
   2277   instr->ReplayEnvironment(current_block_->last_environment());
   2278   return NULL;
   2279 }
   2280 
   2281 
   2282 LInstruction* LChunkBuilder::DoStackCheck(HStackCheck* instr) {
   2283   if (instr->is_function_entry()) {
   2284     LOperand* context = UseFixed(instr->context(), cp);
   2285     return MarkAsCall(new(zone()) LStackCheck(context), instr);
   2286   } else {
   2287     DCHECK(instr->is_backwards_branch());
   2288     LOperand* context = UseAny(instr->context());
   2289     return AssignEnvironment(
   2290         AssignPointerMap(new(zone()) LStackCheck(context)));
   2291   }
   2292 }
   2293 
   2294 
   2295 LInstruction* LChunkBuilder::DoStoreCodeEntry(HStoreCodeEntry* instr) {
   2296   LOperand* function = UseRegister(instr->function());
   2297   LOperand* code_object = UseRegisterAtStart(instr->code_object());
   2298   LOperand* temp = TempRegister();
   2299   return new(zone()) LStoreCodeEntry(function, code_object, temp);
   2300 }
   2301 
   2302 
   2303 LInstruction* LChunkBuilder::DoStoreContextSlot(HStoreContextSlot* instr) {
   2304   LOperand* temp = TempRegister();
   2305   LOperand* context;
   2306   LOperand* value;
   2307   if (instr->NeedsWriteBarrier()) {
   2308     // TODO(all): Replace these constraints when RecordWriteStub has been
   2309     // rewritten.
   2310     context = UseRegisterAndClobber(instr->context());
   2311     value = UseRegisterAndClobber(instr->value());
   2312   } else {
   2313     context = UseRegister(instr->context());
   2314     value = UseRegister(instr->value());
   2315   }
   2316   LInstruction* result = new(zone()) LStoreContextSlot(context, value, temp);
   2317   if (instr->RequiresHoleCheck() && instr->DeoptimizesOnHole()) {
   2318     result = AssignEnvironment(result);
   2319   }
   2320   return result;
   2321 }
   2322 
   2323 
   2324 LInstruction* LChunkBuilder::DoStoreGlobalCell(HStoreGlobalCell* instr) {
   2325   LOperand* value = UseRegister(instr->value());
   2326   if (instr->RequiresHoleCheck()) {
   2327     return AssignEnvironment(new(zone()) LStoreGlobalCell(value,
   2328                                                           TempRegister(),
   2329                                                           TempRegister()));
   2330   } else {
   2331     return new(zone()) LStoreGlobalCell(value, TempRegister(), NULL);
   2332   }
   2333 }
   2334 
   2335 
   2336 LInstruction* LChunkBuilder::DoStoreKeyed(HStoreKeyed* instr) {
   2337   LOperand* key = UseRegisterOrConstant(instr->key());
   2338   LOperand* temp = NULL;
   2339   LOperand* elements = NULL;
   2340   LOperand* val = NULL;
   2341 
   2342   if (!instr->is_typed_elements() &&
   2343       instr->value()->representation().IsTagged() &&
   2344       instr->NeedsWriteBarrier()) {
   2345     // RecordWrite() will clobber all registers.
   2346     elements = UseRegisterAndClobber(instr->elements());
   2347     val = UseRegisterAndClobber(instr->value());
   2348     temp = TempRegister();
   2349   } else {
   2350     elements = UseRegister(instr->elements());
   2351     val = UseRegister(instr->value());
   2352     temp = instr->key()->IsConstant() ? NULL : TempRegister();
   2353   }
   2354 
   2355   if (instr->is_typed_elements()) {
   2356     DCHECK((instr->value()->representation().IsInteger32() &&
   2357             !IsDoubleOrFloatElementsKind(instr->elements_kind())) ||
   2358            (instr->value()->representation().IsDouble() &&
   2359             IsDoubleOrFloatElementsKind(instr->elements_kind())));
   2360     DCHECK((instr->is_fixed_typed_array() &&
   2361             instr->elements()->representation().IsTagged()) ||
   2362            (instr->is_external() &&
   2363             instr->elements()->representation().IsExternal()));
   2364     return new(zone()) LStoreKeyedExternal(elements, key, val, temp);
   2365 
   2366   } else if (instr->value()->representation().IsDouble()) {
   2367     DCHECK(instr->elements()->representation().IsTagged());
   2368     return new(zone()) LStoreKeyedFixedDouble(elements, key, val, temp);
   2369 
   2370   } else {
   2371     DCHECK(instr->elements()->representation().IsTagged());
   2372     DCHECK(instr->value()->representation().IsSmiOrTagged() ||
   2373            instr->value()->representation().IsInteger32());
   2374     return new(zone()) LStoreKeyedFixed(elements, key, val, temp);
   2375   }
   2376 }
   2377 
   2378 
   2379 LInstruction* LChunkBuilder::DoStoreKeyedGeneric(HStoreKeyedGeneric* instr) {
   2380   LOperand* context = UseFixed(instr->context(), cp);
   2381   LOperand* object =
   2382       UseFixed(instr->object(), StoreDescriptor::ReceiverRegister());
   2383   LOperand* key = UseFixed(instr->key(), StoreDescriptor::NameRegister());
   2384   LOperand* value = UseFixed(instr->value(), StoreDescriptor::ValueRegister());
   2385 
   2386   DCHECK(instr->object()->representation().IsTagged());
   2387   DCHECK(instr->key()->representation().IsTagged());
   2388   DCHECK(instr->value()->representation().IsTagged());
   2389 
   2390   return MarkAsCall(
   2391       new(zone()) LStoreKeyedGeneric(context, object, key, value), instr);
   2392 }
   2393 
   2394 
   2395 LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
   2396   // TODO(jbramley): It might be beneficial to allow value to be a constant in
   2397   // some cases. x64 makes use of this with FLAG_track_fields, for example.
   2398 
   2399   LOperand* object = UseRegister(instr->object());
   2400   LOperand* value;
   2401   LOperand* temp0 = NULL;
   2402   LOperand* temp1 = NULL;
   2403 
   2404   if (instr->access().IsExternalMemory() ||
   2405       instr->field_representation().IsDouble()) {
   2406     value = UseRegister(instr->value());
   2407   } else if (instr->NeedsWriteBarrier()) {
   2408     value = UseRegisterAndClobber(instr->value());
   2409     temp0 = TempRegister();
   2410     temp1 = TempRegister();
   2411   } else if (instr->NeedsWriteBarrierForMap()) {
   2412     value = UseRegister(instr->value());
   2413     temp0 = TempRegister();
   2414     temp1 = TempRegister();
   2415   } else {
   2416     value = UseRegister(instr->value());
   2417     temp0 = TempRegister();
   2418   }
   2419 
   2420   return new(zone()) LStoreNamedField(object, value, temp0, temp1);
   2421 }
   2422 
   2423 
   2424 LInstruction* LChunkBuilder::DoStoreNamedGeneric(HStoreNamedGeneric* instr) {
   2425   LOperand* context = UseFixed(instr->context(), cp);
   2426   LOperand* object =
   2427       UseFixed(instr->object(), StoreDescriptor::ReceiverRegister());
   2428   LOperand* value = UseFixed(instr->value(), StoreDescriptor::ValueRegister());
   2429 
   2430   LInstruction* result = new(zone()) LStoreNamedGeneric(context, object, value);
   2431   return MarkAsCall(result, instr);
   2432 }
   2433 
   2434 
   2435 LInstruction* LChunkBuilder::DoStringAdd(HStringAdd* instr) {
   2436   LOperand* context = UseFixed(instr->context(), cp);
   2437   LOperand* left = UseFixed(instr->left(), x1);
   2438   LOperand* right = UseFixed(instr->right(), x0);
   2439 
   2440   LStringAdd* result = new(zone()) LStringAdd(context, left, right);
   2441   return MarkAsCall(DefineFixed(result, x0), instr);
   2442 }
   2443 
   2444 
   2445 LInstruction* LChunkBuilder::DoStringCharCodeAt(HStringCharCodeAt* instr) {
   2446   LOperand* string = UseRegisterAndClobber(instr->string());
   2447   LOperand* index = UseRegisterAndClobber(instr->index());
   2448   LOperand* context = UseAny(instr->context());
   2449   LStringCharCodeAt* result =
   2450       new(zone()) LStringCharCodeAt(context, string, index);
   2451   return AssignPointerMap(DefineAsRegister(result));
   2452 }
   2453 
   2454 
   2455 LInstruction* LChunkBuilder::DoStringCharFromCode(HStringCharFromCode* instr) {
   2456   LOperand* char_code = UseRegister(instr->value());
   2457   LOperand* context = UseAny(instr->context());
   2458   LStringCharFromCode* result =
   2459       new(zone()) LStringCharFromCode(context, char_code);
   2460   return AssignPointerMap(DefineAsRegister(result));
   2461 }
   2462 
   2463 
   2464 LInstruction* LChunkBuilder::DoStringCompareAndBranch(
   2465     HStringCompareAndBranch* instr) {
   2466   DCHECK(instr->left()->representation().IsTagged());
   2467   DCHECK(instr->right()->representation().IsTagged());
   2468   LOperand* context = UseFixed(instr->context(), cp);
   2469   LOperand* left = UseFixed(instr->left(), x1);
   2470   LOperand* right = UseFixed(instr->right(), x0);
   2471   LStringCompareAndBranch* result =
   2472       new(zone()) LStringCompareAndBranch(context, left, right);
   2473   return MarkAsCall(result, instr);
   2474 }
   2475 
   2476 
   2477 LInstruction* LChunkBuilder::DoSub(HSub* instr) {
   2478   if (instr->representation().IsSmiOrInteger32()) {
   2479     DCHECK(instr->left()->representation().Equals(instr->representation()));
   2480     DCHECK(instr->right()->representation().Equals(instr->representation()));
   2481 
   2482     LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
   2483     if (shifted_operation != NULL) {
   2484       return shifted_operation;
   2485     }
   2486 
   2487     LOperand *left;
   2488     if (instr->left()->IsConstant() &&
   2489         (HConstant::cast(instr->left())->Integer32Value() == 0)) {
   2490       left = UseConstant(instr->left());
   2491     } else {
   2492       left = UseRegisterAtStart(instr->left());
   2493     }
   2494     LOperand* right = UseRegisterOrConstantAtStart(instr->right());
   2495     LInstruction* result = instr->representation().IsSmi() ?
   2496         DefineAsRegister(new(zone()) LSubS(left, right)) :
   2497         DefineAsRegister(new(zone()) LSubI(left, right));
   2498     if (instr->CheckFlag(HValue::kCanOverflow)) {
   2499       result = AssignEnvironment(result);
   2500     }
   2501     return result;
   2502   } else if (instr->representation().IsDouble()) {
   2503     return DoArithmeticD(Token::SUB, instr);
   2504   } else {
   2505     return DoArithmeticT(Token::SUB, instr);
   2506   }
   2507 }
   2508 
   2509 
   2510 LInstruction* LChunkBuilder::DoThisFunction(HThisFunction* instr) {
   2511   if (instr->HasNoUses()) {
   2512     return NULL;
   2513   } else {
   2514     return DefineAsRegister(new(zone()) LThisFunction);
   2515   }
   2516 }
   2517 
   2518 
   2519 LInstruction* LChunkBuilder::DoToFastProperties(HToFastProperties* instr) {
   2520   LOperand* object = UseFixed(instr->value(), x0);
   2521   LToFastProperties* result = new(zone()) LToFastProperties(object);
   2522   return MarkAsCall(DefineFixed(result, x0), instr);
   2523 }
   2524 
   2525 
   2526 LInstruction* LChunkBuilder::DoTransitionElementsKind(
   2527     HTransitionElementsKind* instr) {
   2528   if (IsSimpleMapChangeTransition(instr->from_kind(), instr->to_kind())) {
   2529     LOperand* object = UseRegister(instr->object());
   2530     LTransitionElementsKind* result =
   2531         new(zone()) LTransitionElementsKind(object, NULL,
   2532                                             TempRegister(), TempRegister());
   2533     return result;
   2534   } else {
   2535     LOperand* object = UseFixed(instr->object(), x0);
   2536     LOperand* context = UseFixed(instr->context(), cp);
   2537     LTransitionElementsKind* result =
   2538         new(zone()) LTransitionElementsKind(object, context, NULL, NULL);
   2539     return MarkAsCall(result, instr);
   2540   }
   2541 }
   2542 
   2543 
   2544 LInstruction* LChunkBuilder::DoTrapAllocationMemento(
   2545     HTrapAllocationMemento* instr) {
   2546   LOperand* object = UseRegister(instr->object());
   2547   LOperand* temp1 = TempRegister();
   2548   LOperand* temp2 = TempRegister();
   2549   LTrapAllocationMemento* result =
   2550       new(zone()) LTrapAllocationMemento(object, temp1, temp2);
   2551   return AssignEnvironment(result);
   2552 }
   2553 
   2554 
   2555 LInstruction* LChunkBuilder::DoTypeof(HTypeof* instr) {
   2556   LOperand* context = UseFixed(instr->context(), cp);
   2557   // TODO(jbramley): In ARM, this uses UseFixed to force the input to x0.
   2558   // However, LCodeGen::DoTypeof just pushes it to the stack (for CallRuntime)
   2559   // anyway, so the input doesn't have to be in x0. We might be able to improve
   2560   // the ARM back-end a little by relaxing this restriction.
   2561   LTypeof* result =
   2562       new(zone()) LTypeof(context, UseRegisterAtStart(instr->value()));
   2563   return MarkAsCall(DefineFixed(result, x0), instr);
   2564 }
   2565 
   2566 
   2567 LInstruction* LChunkBuilder::DoTypeofIsAndBranch(HTypeofIsAndBranch* instr) {
   2568   // We only need temp registers in some cases, but we can't dereference the
   2569   // instr->type_literal() handle to test that here.
   2570   LOperand* temp1 = TempRegister();
   2571   LOperand* temp2 = TempRegister();
   2572 
   2573   return new(zone()) LTypeofIsAndBranch(
   2574       UseRegister(instr->value()), temp1, temp2);
   2575 }
   2576 
   2577 
   2578 LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
   2579   switch (instr->op()) {
   2580     case kMathAbs: {
   2581       Representation r = instr->representation();
   2582       if (r.IsTagged()) {
   2583         // The tagged case might need to allocate a HeapNumber for the result,
   2584         // so it is handled by a separate LInstruction.
   2585         LOperand* context = UseFixed(instr->context(), cp);
   2586         LOperand* input = UseRegister(instr->value());
   2587         LOperand* temp1 = TempRegister();
   2588         LOperand* temp2 = TempRegister();
   2589         LOperand* temp3 = TempRegister();
   2590         LInstruction* result = DefineAsRegister(
   2591             new(zone()) LMathAbsTagged(context, input, temp1, temp2, temp3));
   2592         return AssignEnvironment(AssignPointerMap(result));
   2593       } else {
   2594         LOperand* input = UseRegisterAtStart(instr->value());
   2595         LInstruction* result = DefineAsRegister(new(zone()) LMathAbs(input));
   2596         if (!r.IsDouble()) result = AssignEnvironment(result);
   2597         return result;
   2598       }
   2599     }
   2600     case kMathExp: {
   2601       DCHECK(instr->representation().IsDouble());
   2602       DCHECK(instr->value()->representation().IsDouble());
   2603       LOperand* input = UseRegister(instr->value());
   2604       LOperand* double_temp1 = TempDoubleRegister();
   2605       LOperand* temp1 = TempRegister();
   2606       LOperand* temp2 = TempRegister();
   2607       LOperand* temp3 = TempRegister();
   2608       LMathExp* result = new(zone()) LMathExp(input, double_temp1,
   2609                                               temp1, temp2, temp3);
   2610       return DefineAsRegister(result);
   2611     }
   2612     case kMathFloor: {
   2613       DCHECK(instr->value()->representation().IsDouble());
   2614       LOperand* input = UseRegisterAtStart(instr->value());
   2615       if (instr->representation().IsInteger32()) {
   2616         LMathFloorI* result = new(zone()) LMathFloorI(input);
   2617         return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
   2618       } else {
   2619         DCHECK(instr->representation().IsDouble());
   2620         LMathFloorD* result = new(zone()) LMathFloorD(input);
   2621         return DefineAsRegister(result);
   2622       }
   2623     }
   2624     case kMathLog: {
   2625       DCHECK(instr->representation().IsDouble());
   2626       DCHECK(instr->value()->representation().IsDouble());
   2627       LOperand* input = UseFixedDouble(instr->value(), d0);
   2628       LMathLog* result = new(zone()) LMathLog(input);
   2629       return MarkAsCall(DefineFixedDouble(result, d0), instr);
   2630     }
   2631     case kMathPowHalf: {
   2632       DCHECK(instr->representation().IsDouble());
   2633       DCHECK(instr->value()->representation().IsDouble());
   2634       LOperand* input = UseRegister(instr->value());
   2635       return DefineAsRegister(new(zone()) LMathPowHalf(input));
   2636     }
   2637     case kMathRound: {
   2638       DCHECK(instr->value()->representation().IsDouble());
   2639       LOperand* input = UseRegister(instr->value());
   2640       if (instr->representation().IsInteger32()) {
   2641         LOperand* temp = TempDoubleRegister();
   2642         LMathRoundI* result = new(zone()) LMathRoundI(input, temp);
   2643         return AssignEnvironment(DefineAsRegister(result));
   2644       } else {
   2645         DCHECK(instr->representation().IsDouble());
   2646         LMathRoundD* result = new(zone()) LMathRoundD(input);
   2647         return DefineAsRegister(result);
   2648       }
   2649     }
   2650     case kMathFround: {
   2651       DCHECK(instr->value()->representation().IsDouble());
   2652       LOperand* input = UseRegister(instr->value());
   2653       LMathFround* result = new (zone()) LMathFround(input);
   2654       return DefineAsRegister(result);
   2655     }
   2656     case kMathSqrt: {
   2657       DCHECK(instr->representation().IsDouble());
   2658       DCHECK(instr->value()->representation().IsDouble());
   2659       LOperand* input = UseRegisterAtStart(instr->value());
   2660       return DefineAsRegister(new(zone()) LMathSqrt(input));
   2661     }
   2662     case kMathClz32: {
   2663       DCHECK(instr->representation().IsInteger32());
   2664       DCHECK(instr->value()->representation().IsInteger32());
   2665       LOperand* input = UseRegisterAtStart(instr->value());
   2666       return DefineAsRegister(new(zone()) LMathClz32(input));
   2667     }
   2668     default:
   2669       UNREACHABLE();
   2670       return NULL;
   2671   }
   2672 }
   2673 
   2674 
   2675 LInstruction* LChunkBuilder::DoUnknownOSRValue(HUnknownOSRValue* instr) {
   2676   // Use an index that corresponds to the location in the unoptimized frame,
   2677   // which the optimized frame will subsume.
   2678   int env_index = instr->index();
   2679   int spill_index = 0;
   2680   if (instr->environment()->is_parameter_index(env_index)) {
   2681     spill_index = chunk_->GetParameterStackSlot(env_index);
   2682   } else {
   2683     spill_index = env_index - instr->environment()->first_local_index();
   2684     if (spill_index > LUnallocated::kMaxFixedSlotIndex) {
   2685       Retry(kTooManySpillSlotsNeededForOSR);
   2686       spill_index = 0;
   2687     }
   2688   }
   2689   return DefineAsSpilled(new(zone()) LUnknownOSRValue, spill_index);
   2690 }
   2691 
   2692 
   2693 LInstruction* LChunkBuilder::DoUseConst(HUseConst* instr) {
   2694   return NULL;
   2695 }
   2696 
   2697 
   2698 LInstruction* LChunkBuilder::DoForInPrepareMap(HForInPrepareMap* instr) {
   2699   LOperand* context = UseFixed(instr->context(), cp);
   2700   // Assign object to a fixed register different from those already used in
   2701   // LForInPrepareMap.
   2702   LOperand* object = UseFixed(instr->enumerable(), x0);
   2703   LForInPrepareMap* result = new(zone()) LForInPrepareMap(context, object);
   2704   return MarkAsCall(DefineFixed(result, x0), instr, CAN_DEOPTIMIZE_EAGERLY);
   2705 }
   2706 
   2707 
   2708 LInstruction* LChunkBuilder::DoForInCacheArray(HForInCacheArray* instr) {
   2709   LOperand* map = UseRegister(instr->map());
   2710   return AssignEnvironment(DefineAsRegister(new(zone()) LForInCacheArray(map)));
   2711 }
   2712 
   2713 
   2714 LInstruction* LChunkBuilder::DoCheckMapValue(HCheckMapValue* instr) {
   2715   LOperand* value = UseRegisterAtStart(instr->value());
   2716   LOperand* map = UseRegister(instr->map());
   2717   LOperand* temp = TempRegister();
   2718   return AssignEnvironment(new(zone()) LCheckMapValue(value, map, temp));
   2719 }
   2720 
   2721 
   2722 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   2723   LOperand* object = UseRegisterAtStart(instr->object());
   2724   LOperand* index = UseRegisterAndClobber(instr->index());
   2725   LLoadFieldByIndex* load = new(zone()) LLoadFieldByIndex(object, index);
   2726   LInstruction* result = DefineSameAsFirst(load);
   2727   return AssignPointerMap(result);
   2728 }
   2729 
   2730 
   2731 LInstruction* LChunkBuilder::DoWrapReceiver(HWrapReceiver* instr) {
   2732   LOperand* receiver = UseRegister(instr->receiver());
   2733   LOperand* function = UseRegister(instr->function());
   2734   LWrapReceiver* result = new(zone()) LWrapReceiver(receiver, function);
   2735   return AssignEnvironment(DefineAsRegister(result));
   2736 }
   2737 
   2738 
   2739 LInstruction* LChunkBuilder::DoStoreFrameContext(HStoreFrameContext* instr) {
   2740   LOperand* context = UseRegisterAtStart(instr->context());
   2741   return new(zone()) LStoreFrameContext(context);
   2742 }
   2743 
   2744 
   2745 LInstruction* LChunkBuilder::DoAllocateBlockContext(
   2746     HAllocateBlockContext* instr) {
   2747   LOperand* context = UseFixed(instr->context(), cp);
   2748   LOperand* function = UseRegisterAtStart(instr->function());
   2749   LAllocateBlockContext* result =
   2750       new(zone()) LAllocateBlockContext(context, function);
   2751   return MarkAsCall(DefineFixed(result, cp), instr);
   2752 }
   2753 
   2754 
   2755 } }  // namespace v8::internal
   2756