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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/crankshaft/arm64/lithium-arm64.h"
      6 
      7 #include <sstream>
      8 
      9 #include "src/crankshaft/arm64/lithium-codegen-arm64.h"
     10 #include "src/crankshaft/hydrogen-osr.h"
     11 #include "src/crankshaft/lithium-inl.h"
     12 
     13 namespace v8 {
     14 namespace internal {
     15 
     16 #define DEFINE_COMPILE(type)                            \
     17   void L##type::CompileToNative(LCodeGen* generator) {  \
     18     generator->Do##type(this);                          \
     19   }
     20 LITHIUM_CONCRETE_INSTRUCTION_LIST(DEFINE_COMPILE)
     21 #undef DEFINE_COMPILE
     22 
     23 #ifdef DEBUG
     24 void LInstruction::VerifyCall() {
     25   // Call instructions can use only fixed registers as temporaries and
     26   // outputs because all registers are blocked by the calling convention.
     27   // Inputs operands must use a fixed register or use-at-start policy or
     28   // a non-register policy.
     29   DCHECK(Output() == NULL ||
     30          LUnallocated::cast(Output())->HasFixedPolicy() ||
     31          !LUnallocated::cast(Output())->HasRegisterPolicy());
     32   for (UseIterator it(this); !it.Done(); it.Advance()) {
     33     LUnallocated* operand = LUnallocated::cast(it.Current());
     34     DCHECK(operand->HasFixedPolicy() ||
     35            operand->IsUsedAtStart());
     36   }
     37   for (TempIterator it(this); !it.Done(); it.Advance()) {
     38     LUnallocated* operand = LUnallocated::cast(it.Current());
     39     DCHECK(operand->HasFixedPolicy() ||!operand->HasRegisterPolicy());
     40   }
     41 }
     42 #endif
     43 
     44 
     45 void LLabel::PrintDataTo(StringStream* stream) {
     46   LGap::PrintDataTo(stream);
     47   LLabel* rep = replacement();
     48   if (rep != NULL) {
     49     stream->Add(" Dead block replaced with B%d", rep->block_id());
     50   }
     51 }
     52 
     53 
     54 void LAccessArgumentsAt::PrintDataTo(StringStream* stream) {
     55   arguments()->PrintTo(stream);
     56   stream->Add(" length ");
     57   length()->PrintTo(stream);
     58   stream->Add(" index ");
     59   index()->PrintTo(stream);
     60 }
     61 
     62 
     63 void LBranch::PrintDataTo(StringStream* stream) {
     64   stream->Add("B%d | B%d on ", true_block_id(), false_block_id());
     65   value()->PrintTo(stream);
     66 }
     67 
     68 
     69 void LCallWithDescriptor::PrintDataTo(StringStream* stream) {
     70   for (int i = 0; i < InputCount(); i++) {
     71     InputAt(i)->PrintTo(stream);
     72     stream->Add(" ");
     73   }
     74   stream->Add("#%d / ", arity());
     75 }
     76 
     77 
     78 void LCallNewArray::PrintDataTo(StringStream* stream) {
     79   stream->Add("= ");
     80   constructor()->PrintTo(stream);
     81   stream->Add(" #%d / ", arity());
     82   ElementsKind kind = hydrogen()->elements_kind();
     83   stream->Add(" (%s) ", ElementsKindToString(kind));
     84 }
     85 
     86 
     87 void LClassOfTestAndBranch::PrintDataTo(StringStream* stream) {
     88   stream->Add("if class_of_test(");
     89   value()->PrintTo(stream);
     90   stream->Add(", \"%o\") then B%d else B%d",
     91               *hydrogen()->class_name(),
     92               true_block_id(),
     93               false_block_id());
     94 }
     95 
     96 
     97 void LCompareNumericAndBranch::PrintDataTo(StringStream* stream) {
     98   stream->Add("if ");
     99   left()->PrintTo(stream);
    100   stream->Add(" %s ", Token::String(op()));
    101   right()->PrintTo(stream);
    102   stream->Add(" then B%d else B%d", true_block_id(), false_block_id());
    103 }
    104 
    105 
    106 void LHasCachedArrayIndexAndBranch::PrintDataTo(StringStream* stream) {
    107   stream->Add("if has_cached_array_index(");
    108   value()->PrintTo(stream);
    109   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    110 }
    111 
    112 
    113 bool LGoto::HasInterestingComment(LCodeGen* gen) const {
    114   return !gen->IsNextEmittedBlock(block_id());
    115 }
    116 
    117 
    118 void LGoto::PrintDataTo(StringStream* stream) {
    119   stream->Add("B%d", block_id());
    120 }
    121 
    122 
    123 void LInnerAllocatedObject::PrintDataTo(StringStream* stream) {
    124   stream->Add(" = ");
    125   base_object()->PrintTo(stream);
    126   stream->Add(" + ");
    127   offset()->PrintTo(stream);
    128 }
    129 
    130 
    131 void LInvokeFunction::PrintDataTo(StringStream* stream) {
    132   stream->Add("= ");
    133   function()->PrintTo(stream);
    134   stream->Add(" #%d / ", arity());
    135 }
    136 
    137 
    138 void LInstruction::PrintTo(StringStream* stream) {
    139   stream->Add("%s ", this->Mnemonic());
    140 
    141   PrintOutputOperandTo(stream);
    142 
    143   PrintDataTo(stream);
    144 
    145   if (HasEnvironment()) {
    146     stream->Add(" ");
    147     environment()->PrintTo(stream);
    148   }
    149 
    150   if (HasPointerMap()) {
    151     stream->Add(" ");
    152     pointer_map()->PrintTo(stream);
    153   }
    154 }
    155 
    156 
    157 void LInstruction::PrintDataTo(StringStream* stream) {
    158   stream->Add("= ");
    159   for (int i = 0; i < InputCount(); i++) {
    160     if (i > 0) stream->Add(" ");
    161     if (InputAt(i) == NULL) {
    162       stream->Add("NULL");
    163     } else {
    164       InputAt(i)->PrintTo(stream);
    165     }
    166   }
    167 }
    168 
    169 
    170 void LInstruction::PrintOutputOperandTo(StringStream* stream) {
    171   if (HasResult()) result()->PrintTo(stream);
    172 }
    173 
    174 
    175 void LHasInstanceTypeAndBranch::PrintDataTo(StringStream* stream) {
    176   stream->Add("if has_instance_type(");
    177   value()->PrintTo(stream);
    178   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    179 }
    180 
    181 
    182 void LIsStringAndBranch::PrintDataTo(StringStream* stream) {
    183   stream->Add("if is_string(");
    184   value()->PrintTo(stream);
    185   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    186 }
    187 
    188 
    189 void LIsSmiAndBranch::PrintDataTo(StringStream* stream) {
    190   stream->Add("if is_smi(");
    191   value()->PrintTo(stream);
    192   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    193 }
    194 
    195 
    196 void LTypeofIsAndBranch::PrintDataTo(StringStream* stream) {
    197   stream->Add("if typeof ");
    198   value()->PrintTo(stream);
    199   stream->Add(" == \"%s\" then B%d else B%d",
    200               hydrogen()->type_literal()->ToCString().get(),
    201               true_block_id(), false_block_id());
    202 }
    203 
    204 
    205 void LIsUndetectableAndBranch::PrintDataTo(StringStream* stream) {
    206   stream->Add("if is_undetectable(");
    207   value()->PrintTo(stream);
    208   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    209 }
    210 
    211 
    212 bool LGap::IsRedundant() const {
    213   for (int i = 0; i < 4; i++) {
    214     if ((parallel_moves_[i] != NULL) && !parallel_moves_[i]->IsRedundant()) {
    215       return false;
    216     }
    217   }
    218 
    219   return true;
    220 }
    221 
    222 
    223 void LGap::PrintDataTo(StringStream* stream) {
    224   for (int i = 0; i < 4; i++) {
    225     stream->Add("(");
    226     if (parallel_moves_[i] != NULL) {
    227       parallel_moves_[i]->PrintDataTo(stream);
    228     }
    229     stream->Add(") ");
    230   }
    231 }
    232 
    233 
    234 void LLoadContextSlot::PrintDataTo(StringStream* stream) {
    235   context()->PrintTo(stream);
    236   stream->Add("[%d]", slot_index());
    237 }
    238 
    239 
    240 void LStoreCodeEntry::PrintDataTo(StringStream* stream) {
    241   stream->Add(" = ");
    242   function()->PrintTo(stream);
    243   stream->Add(".code_entry = ");
    244   code_object()->PrintTo(stream);
    245 }
    246 
    247 
    248 void LStoreContextSlot::PrintDataTo(StringStream* stream) {
    249   context()->PrintTo(stream);
    250   stream->Add("[%d] <- ", slot_index());
    251   value()->PrintTo(stream);
    252 }
    253 
    254 
    255 void LStoreKeyedGeneric::PrintDataTo(StringStream* stream) {
    256   object()->PrintTo(stream);
    257   stream->Add("[");
    258   key()->PrintTo(stream);
    259   stream->Add("] <- ");
    260   value()->PrintTo(stream);
    261 }
    262 
    263 
    264 void LStoreNamedField::PrintDataTo(StringStream* stream) {
    265   object()->PrintTo(stream);
    266   std::ostringstream os;
    267   os << hydrogen()->access();
    268   stream->Add(os.str().c_str());
    269   stream->Add(" <- ");
    270   value()->PrintTo(stream);
    271 }
    272 
    273 
    274 void LStoreNamedGeneric::PrintDataTo(StringStream* stream) {
    275   object()->PrintTo(stream);
    276   stream->Add(".");
    277   stream->Add(String::cast(*name())->ToCString().get());
    278   stream->Add(" <- ");
    279   value()->PrintTo(stream);
    280 }
    281 
    282 
    283 void LStringCompareAndBranch::PrintDataTo(StringStream* stream) {
    284   stream->Add("if string_compare(");
    285   left()->PrintTo(stream);
    286   right()->PrintTo(stream);
    287   stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
    288 }
    289 
    290 
    291 void LTransitionElementsKind::PrintDataTo(StringStream* stream) {
    292   object()->PrintTo(stream);
    293   stream->Add("%p -> %p", *original_map(), *transitioned_map());
    294 }
    295 
    296 
    297 template<int T>
    298 void LUnaryMathOperation<T>::PrintDataTo(StringStream* stream) {
    299   value()->PrintTo(stream);
    300 }
    301 
    302 
    303 const char* LArithmeticD::Mnemonic() const {
    304   switch (op()) {
    305     case Token::ADD: return "add-d";
    306     case Token::SUB: return "sub-d";
    307     case Token::MUL: return "mul-d";
    308     case Token::DIV: return "div-d";
    309     case Token::MOD: return "mod-d";
    310     default:
    311       UNREACHABLE();
    312       return NULL;
    313   }
    314 }
    315 
    316 
    317 const char* LArithmeticT::Mnemonic() const {
    318   switch (op()) {
    319     case Token::ADD: return "add-t";
    320     case Token::SUB: return "sub-t";
    321     case Token::MUL: return "mul-t";
    322     case Token::MOD: return "mod-t";
    323     case Token::DIV: return "div-t";
    324     case Token::BIT_AND: return "bit-and-t";
    325     case Token::BIT_OR: return "bit-or-t";
    326     case Token::BIT_XOR: return "bit-xor-t";
    327     case Token::ROR: return "ror-t";
    328     case Token::SHL: return "shl-t";
    329     case Token::SAR: return "sar-t";
    330     case Token::SHR: return "shr-t";
    331     default:
    332       UNREACHABLE();
    333       return NULL;
    334   }
    335 }
    336 
    337 
    338 LUnallocated* LChunkBuilder::ToUnallocated(Register reg) {
    339   return new (zone()) LUnallocated(LUnallocated::FIXED_REGISTER, reg.code());
    340 }
    341 
    342 
    343 LUnallocated* LChunkBuilder::ToUnallocated(DoubleRegister reg) {
    344   return new (zone())
    345       LUnallocated(LUnallocated::FIXED_DOUBLE_REGISTER, reg.code());
    346 }
    347 
    348 
    349 LOperand* LChunkBuilder::Use(HValue* value, LUnallocated* operand) {
    350   if (value->EmitAtUses()) {
    351     HInstruction* instr = HInstruction::cast(value);
    352     VisitInstruction(instr);
    353   }
    354   operand->set_virtual_register(value->id());
    355   return operand;
    356 }
    357 
    358 
    359 LOperand* LChunkBuilder::UseFixed(HValue* value, Register fixed_register) {
    360   return Use(value, ToUnallocated(fixed_register));
    361 }
    362 
    363 
    364 LOperand* LChunkBuilder::UseFixedDouble(HValue* value,
    365                                         DoubleRegister fixed_register) {
    366   return Use(value, ToUnallocated(fixed_register));
    367 }
    368 
    369 
    370 LOperand* LChunkBuilder::UseRegister(HValue* value) {
    371   return Use(value, new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER));
    372 }
    373 
    374 
    375 LOperand* LChunkBuilder::UseRegisterAndClobber(HValue* value) {
    376   return Use(value, new(zone()) LUnallocated(LUnallocated::WRITABLE_REGISTER));
    377 }
    378 
    379 
    380 LOperand* LChunkBuilder::UseRegisterAtStart(HValue* value) {
    381   return Use(value,
    382              new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER,
    383                                       LUnallocated::USED_AT_START));
    384 }
    385 
    386 
    387 LOperand* LChunkBuilder::UseRegisterOrConstant(HValue* value) {
    388   return value->IsConstant() ? UseConstant(value) : UseRegister(value);
    389 }
    390 
    391 
    392 LOperand* LChunkBuilder::UseRegisterOrConstantAtStart(HValue* value) {
    393   return value->IsConstant() ? UseConstant(value) : UseRegisterAtStart(value);
    394 }
    395 
    396 
    397 LConstantOperand* LChunkBuilder::UseConstant(HValue* value) {
    398   return chunk_->DefineConstantOperand(HConstant::cast(value));
    399 }
    400 
    401 
    402 LOperand* LChunkBuilder::UseAny(HValue* value) {
    403   return value->IsConstant()
    404       ? UseConstant(value)
    405       : Use(value, new(zone()) LUnallocated(LUnallocated::ANY));
    406 }
    407 
    408 
    409 LInstruction* LChunkBuilder::Define(LTemplateResultInstruction<1>* instr,
    410                                     LUnallocated* result) {
    411   result->set_virtual_register(current_instruction_->id());
    412   instr->set_result(result);
    413   return instr;
    414 }
    415 
    416 
    417 LInstruction* LChunkBuilder::DefineAsRegister(
    418     LTemplateResultInstruction<1>* instr) {
    419   return Define(instr,
    420                 new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER));
    421 }
    422 
    423 
    424 LInstruction* LChunkBuilder::DefineAsSpilled(
    425     LTemplateResultInstruction<1>* instr, int index) {
    426   return Define(instr,
    427                 new(zone()) LUnallocated(LUnallocated::FIXED_SLOT, index));
    428 }
    429 
    430 
    431 LInstruction* LChunkBuilder::DefineSameAsFirst(
    432     LTemplateResultInstruction<1>* instr) {
    433   return Define(instr,
    434                 new(zone()) LUnallocated(LUnallocated::SAME_AS_FIRST_INPUT));
    435 }
    436 
    437 
    438 LInstruction* LChunkBuilder::DefineFixed(
    439     LTemplateResultInstruction<1>* instr, Register reg) {
    440   return Define(instr, ToUnallocated(reg));
    441 }
    442 
    443 
    444 LInstruction* LChunkBuilder::DefineFixedDouble(
    445     LTemplateResultInstruction<1>* instr, DoubleRegister reg) {
    446   return Define(instr, ToUnallocated(reg));
    447 }
    448 
    449 
    450 LInstruction* LChunkBuilder::MarkAsCall(LInstruction* instr,
    451                                         HInstruction* hinstr,
    452                                         CanDeoptimize can_deoptimize) {
    453   info()->MarkAsNonDeferredCalling();
    454 #ifdef DEBUG
    455   instr->VerifyCall();
    456 #endif
    457   instr->MarkAsCall();
    458   instr = AssignPointerMap(instr);
    459 
    460   // If instruction does not have side-effects lazy deoptimization
    461   // after the call will try to deoptimize to the point before the call.
    462   // Thus we still need to attach environment to this call even if
    463   // call sequence can not deoptimize eagerly.
    464   bool needs_environment =
    465       (can_deoptimize == CAN_DEOPTIMIZE_EAGERLY) ||
    466       !hinstr->HasObservableSideEffects();
    467   if (needs_environment && !instr->HasEnvironment()) {
    468     instr = AssignEnvironment(instr);
    469     // We can't really figure out if the environment is needed or not.
    470     instr->environment()->set_has_been_used();
    471   }
    472 
    473   return instr;
    474 }
    475 
    476 
    477 LInstruction* LChunkBuilder::AssignPointerMap(LInstruction* instr) {
    478   DCHECK(!instr->HasPointerMap());
    479   instr->set_pointer_map(new(zone()) LPointerMap(zone()));
    480   return instr;
    481 }
    482 
    483 
    484 LUnallocated* LChunkBuilder::TempRegister() {
    485   LUnallocated* operand =
    486       new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER);
    487   int vreg = allocator_->GetVirtualRegister();
    488   if (!allocator_->AllocationOk()) {
    489     Abort(kOutOfVirtualRegistersWhileTryingToAllocateTempRegister);
    490     vreg = 0;
    491   }
    492   operand->set_virtual_register(vreg);
    493   return operand;
    494 }
    495 
    496 
    497 LUnallocated* LChunkBuilder::TempDoubleRegister() {
    498   LUnallocated* operand =
    499       new(zone()) LUnallocated(LUnallocated::MUST_HAVE_DOUBLE_REGISTER);
    500   int vreg = allocator_->GetVirtualRegister();
    501   if (!allocator_->AllocationOk()) {
    502     Abort(kOutOfVirtualRegistersWhileTryingToAllocateTempRegister);
    503     vreg = 0;
    504   }
    505   operand->set_virtual_register(vreg);
    506   return operand;
    507 }
    508 
    509 int LPlatformChunk::GetNextSpillIndex() { return current_frame_slots_++; }
    510 
    511 LOperand* LPlatformChunk::GetNextSpillSlot(RegisterKind kind) {
    512   int index = GetNextSpillIndex();
    513   if (kind == DOUBLE_REGISTERS) {
    514     return LDoubleStackSlot::Create(index, zone());
    515   } else {
    516     DCHECK(kind == GENERAL_REGISTERS);
    517     return LStackSlot::Create(index, zone());
    518   }
    519 }
    520 
    521 
    522 LOperand* LChunkBuilder::FixedTemp(Register reg) {
    523   LUnallocated* operand = ToUnallocated(reg);
    524   DCHECK(operand->HasFixedPolicy());
    525   return operand;
    526 }
    527 
    528 
    529 LOperand* LChunkBuilder::FixedTemp(DoubleRegister reg) {
    530   LUnallocated* operand = ToUnallocated(reg);
    531   DCHECK(operand->HasFixedPolicy());
    532   return operand;
    533 }
    534 
    535 
    536 LPlatformChunk* LChunkBuilder::Build() {
    537   DCHECK(is_unused());
    538   chunk_ = new(zone()) LPlatformChunk(info_, graph_);
    539   LPhase phase("L_Building chunk", chunk_);
    540   status_ = BUILDING;
    541 
    542   // If compiling for OSR, reserve space for the unoptimized frame,
    543   // which will be subsumed into this frame.
    544   if (graph()->has_osr()) {
    545     // TODO(all): GetNextSpillIndex just increments a field. It has no other
    546     // side effects, so we should get rid of this loop.
    547     for (int i = graph()->osr()->UnoptimizedFrameSlots(); i > 0; i--) {
    548       chunk_->GetNextSpillIndex();
    549     }
    550   }
    551 
    552   const ZoneList<HBasicBlock*>* blocks = graph_->blocks();
    553   for (int i = 0; i < blocks->length(); i++) {
    554     DoBasicBlock(blocks->at(i));
    555     if (is_aborted()) return NULL;
    556   }
    557   status_ = DONE;
    558   return chunk_;
    559 }
    560 
    561 
    562 void LChunkBuilder::DoBasicBlock(HBasicBlock* block) {
    563   DCHECK(is_building());
    564   current_block_ = block;
    565 
    566   if (block->IsStartBlock()) {
    567     block->UpdateEnvironment(graph_->start_environment());
    568     argument_count_ = 0;
    569   } else if (block->predecessors()->length() == 1) {
    570     // We have a single predecessor => copy environment and outgoing
    571     // argument count from the predecessor.
    572     DCHECK(block->phis()->length() == 0);
    573     HBasicBlock* pred = block->predecessors()->at(0);
    574     HEnvironment* last_environment = pred->last_environment();
    575     DCHECK(last_environment != NULL);
    576 
    577     // Only copy the environment, if it is later used again.
    578     if (pred->end()->SecondSuccessor() == NULL) {
    579       DCHECK(pred->end()->FirstSuccessor() == block);
    580     } else {
    581       if ((pred->end()->FirstSuccessor()->block_id() > block->block_id()) ||
    582           (pred->end()->SecondSuccessor()->block_id() > block->block_id())) {
    583         last_environment = last_environment->Copy();
    584       }
    585     }
    586     block->UpdateEnvironment(last_environment);
    587     DCHECK(pred->argument_count() >= 0);
    588     argument_count_ = pred->argument_count();
    589   } else {
    590     // We are at a state join => process phis.
    591     HBasicBlock* pred = block->predecessors()->at(0);
    592     // No need to copy the environment, it cannot be used later.
    593     HEnvironment* last_environment = pred->last_environment();
    594     for (int i = 0; i < block->phis()->length(); ++i) {
    595       HPhi* phi = block->phis()->at(i);
    596       if (phi->HasMergedIndex()) {
    597         last_environment->SetValueAt(phi->merged_index(), phi);
    598       }
    599     }
    600     for (int i = 0; i < block->deleted_phis()->length(); ++i) {
    601       if (block->deleted_phis()->at(i) < last_environment->length()) {
    602         last_environment->SetValueAt(block->deleted_phis()->at(i),
    603                                      graph_->GetConstantUndefined());
    604       }
    605     }
    606     block->UpdateEnvironment(last_environment);
    607     // Pick up the outgoing argument count of one of the predecessors.
    608     argument_count_ = pred->argument_count();
    609   }
    610 
    611   // Translate hydrogen instructions to lithium ones for the current block.
    612   HInstruction* current = block->first();
    613   int start = chunk_->instructions()->length();
    614   while ((current != NULL) && !is_aborted()) {
    615     // Code for constants in registers is generated lazily.
    616     if (!current->EmitAtUses()) {
    617       VisitInstruction(current);
    618     }
    619     current = current->next();
    620   }
    621   int end = chunk_->instructions()->length() - 1;
    622   if (end >= start) {
    623     block->set_first_instruction_index(start);
    624     block->set_last_instruction_index(end);
    625   }
    626   block->set_argument_count(argument_count_);
    627   current_block_ = NULL;
    628 }
    629 
    630 
    631 void LChunkBuilder::VisitInstruction(HInstruction* current) {
    632   HInstruction* old_current = current_instruction_;
    633   current_instruction_ = current;
    634 
    635   LInstruction* instr = NULL;
    636   if (current->CanReplaceWithDummyUses()) {
    637     if (current->OperandCount() == 0) {
    638       instr = DefineAsRegister(new(zone()) LDummy());
    639     } else {
    640       DCHECK(!current->OperandAt(0)->IsControlInstruction());
    641       instr = DefineAsRegister(new(zone())
    642           LDummyUse(UseAny(current->OperandAt(0))));
    643     }
    644     for (int i = 1; i < current->OperandCount(); ++i) {
    645       if (current->OperandAt(i)->IsControlInstruction()) continue;
    646       LInstruction* dummy =
    647           new(zone()) LDummyUse(UseAny(current->OperandAt(i)));
    648       dummy->set_hydrogen_value(current);
    649       chunk_->AddInstruction(dummy, current_block_);
    650     }
    651   } else {
    652     HBasicBlock* successor;
    653     if (current->IsControlInstruction() &&
    654         HControlInstruction::cast(current)->KnownSuccessorBlock(&successor) &&
    655         successor != NULL) {
    656       instr = new(zone()) LGoto(successor);
    657     } else {
    658       instr = current->CompileToLithium(this);
    659     }
    660   }
    661 
    662   argument_count_ += current->argument_delta();
    663   DCHECK(argument_count_ >= 0);
    664 
    665   if (instr != NULL) {
    666     AddInstruction(instr, current);
    667   }
    668 
    669   current_instruction_ = old_current;
    670 }
    671 
    672 
    673 void LChunkBuilder::AddInstruction(LInstruction* instr,
    674                                    HInstruction* hydrogen_val) {
    675   // Associate the hydrogen instruction first, since we may need it for
    676   // the ClobbersRegisters() or ClobbersDoubleRegisters() calls below.
    677   instr->set_hydrogen_value(hydrogen_val);
    678 
    679 #if DEBUG
    680   // Make sure that the lithium instruction has either no fixed register
    681   // constraints in temps or the result OR no uses that are only used at
    682   // start. If this invariant doesn't hold, the register allocator can decide
    683   // to insert a split of a range immediately before the instruction due to an
    684   // already allocated register needing to be used for the instruction's fixed
    685   // register constraint. In this case, the register allocator won't see an
    686   // interference between the split child and the use-at-start (it would if
    687   // the it was just a plain use), so it is free to move the split child into
    688   // the same register that is used for the use-at-start.
    689   // See https://code.google.com/p/chromium/issues/detail?id=201590
    690   if (!(instr->ClobbersRegisters() &&
    691         instr->ClobbersDoubleRegisters(isolate()))) {
    692     int fixed = 0;
    693     int used_at_start = 0;
    694     for (UseIterator it(instr); !it.Done(); it.Advance()) {
    695       LUnallocated* operand = LUnallocated::cast(it.Current());
    696       if (operand->IsUsedAtStart()) ++used_at_start;
    697     }
    698     if (instr->Output() != NULL) {
    699       if (LUnallocated::cast(instr->Output())->HasFixedPolicy()) ++fixed;
    700     }
    701     for (TempIterator it(instr); !it.Done(); it.Advance()) {
    702       LUnallocated* operand = LUnallocated::cast(it.Current());
    703       if (operand->HasFixedPolicy()) ++fixed;
    704     }
    705     DCHECK(fixed == 0 || used_at_start == 0);
    706   }
    707 #endif
    708 
    709   if (FLAG_stress_pointer_maps && !instr->HasPointerMap()) {
    710     instr = AssignPointerMap(instr);
    711   }
    712   if (FLAG_stress_environments && !instr->HasEnvironment()) {
    713     instr = AssignEnvironment(instr);
    714   }
    715   chunk_->AddInstruction(instr, current_block_);
    716 
    717   CreateLazyBailoutForCall(current_block_, instr, hydrogen_val);
    718 }
    719 
    720 
    721 LInstruction* LChunkBuilder::AssignEnvironment(LInstruction* instr) {
    722   HEnvironment* hydrogen_env = current_block_->last_environment();
    723   return LChunkBuilderBase::AssignEnvironment(instr, hydrogen_env);
    724 }
    725 
    726 
    727 LInstruction* LChunkBuilder::DoPrologue(HPrologue* instr) {
    728   LInstruction* result = new (zone()) LPrologue();
    729   if (info_->scope()->num_heap_slots() > 0) {
    730     result = MarkAsCall(result, instr);
    731   }
    732   return result;
    733 }
    734 
    735 
    736 LInstruction* LChunkBuilder::DoAbnormalExit(HAbnormalExit* instr) {
    737   // The control instruction marking the end of a block that completed
    738   // abruptly (e.g., threw an exception). There is nothing specific to do.
    739   return NULL;
    740 }
    741 
    742 
    743 LInstruction* LChunkBuilder::DoArithmeticD(Token::Value op,
    744                                            HArithmeticBinaryOperation* instr) {
    745   DCHECK(instr->representation().IsDouble());
    746   DCHECK(instr->left()->representation().IsDouble());
    747   DCHECK(instr->right()->representation().IsDouble());
    748 
    749   if (op == Token::MOD) {
    750     LOperand* left = UseFixedDouble(instr->left(), d0);
    751     LOperand* right = UseFixedDouble(instr->right(), d1);
    752     LArithmeticD* result = new(zone()) LArithmeticD(Token::MOD, left, right);
    753     return MarkAsCall(DefineFixedDouble(result, d0), instr);
    754   } else {
    755     LOperand* left = UseRegisterAtStart(instr->left());
    756     LOperand* right = UseRegisterAtStart(instr->right());
    757     LArithmeticD* result = new(zone()) LArithmeticD(op, left, right);
    758     return DefineAsRegister(result);
    759   }
    760 }
    761 
    762 
    763 LInstruction* LChunkBuilder::DoArithmeticT(Token::Value op,
    764                                            HBinaryOperation* instr) {
    765   DCHECK((op == Token::ADD) || (op == Token::SUB) || (op == Token::MUL) ||
    766          (op == Token::DIV) || (op == Token::MOD) || (op == Token::SHR) ||
    767          (op == Token::SHL) || (op == Token::SAR) || (op == Token::ROR) ||
    768          (op == Token::BIT_OR) || (op == Token::BIT_AND) ||
    769          (op == Token::BIT_XOR));
    770   HValue* left = instr->left();
    771   HValue* right = instr->right();
    772 
    773   // TODO(jbramley): Once we've implemented smi support for all arithmetic
    774   // operations, these assertions should check IsTagged().
    775   DCHECK(instr->representation().IsSmiOrTagged());
    776   DCHECK(left->representation().IsSmiOrTagged());
    777   DCHECK(right->representation().IsSmiOrTagged());
    778 
    779   LOperand* context = UseFixed(instr->context(), cp);
    780   LOperand* left_operand = UseFixed(left, x1);
    781   LOperand* right_operand = UseFixed(right, x0);
    782   LArithmeticT* result =
    783       new(zone()) LArithmeticT(op, context, left_operand, right_operand);
    784   return MarkAsCall(DefineFixed(result, x0), instr);
    785 }
    786 
    787 
    788 LInstruction* LChunkBuilder::DoAccessArgumentsAt(HAccessArgumentsAt* instr) {
    789   info()->MarkAsRequiresFrame();
    790   LOperand* args = NULL;
    791   LOperand* length = NULL;
    792   LOperand* index = NULL;
    793 
    794   if (instr->length()->IsConstant() && instr->index()->IsConstant()) {
    795     args = UseRegisterAtStart(instr->arguments());
    796     length = UseConstant(instr->length());
    797     index = UseConstant(instr->index());
    798   } else {
    799     args = UseRegister(instr->arguments());
    800     length = UseRegisterAtStart(instr->length());
    801     index = UseRegisterOrConstantAtStart(instr->index());
    802   }
    803 
    804   return DefineAsRegister(new(zone()) LAccessArgumentsAt(args, length, index));
    805 }
    806 
    807 
    808 LInstruction* LChunkBuilder::DoAdd(HAdd* instr) {
    809   if (instr->representation().IsSmiOrInteger32()) {
    810     DCHECK(instr->left()->representation().Equals(instr->representation()));
    811     DCHECK(instr->right()->representation().Equals(instr->representation()));
    812 
    813     LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
    814     if (shifted_operation != NULL) {
    815       return shifted_operation;
    816     }
    817 
    818     LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand());
    819     LOperand* right =
    820         UseRegisterOrConstantAtStart(instr->BetterRightOperand());
    821     LInstruction* result = instr->representation().IsSmi() ?
    822         DefineAsRegister(new(zone()) LAddS(left, right)) :
    823         DefineAsRegister(new(zone()) LAddI(left, right));
    824     if (instr->CheckFlag(HValue::kCanOverflow)) {
    825       result = AssignEnvironment(result);
    826     }
    827     return result;
    828   } else if (instr->representation().IsExternal()) {
    829     DCHECK(instr->IsConsistentExternalRepresentation());
    830     DCHECK(!instr->CheckFlag(HValue::kCanOverflow));
    831     LOperand* left = UseRegisterAtStart(instr->left());
    832     LOperand* right = UseRegisterOrConstantAtStart(instr->right());
    833     return DefineAsRegister(new(zone()) LAddE(left, right));
    834   } else if (instr->representation().IsDouble()) {
    835     return DoArithmeticD(Token::ADD, instr);
    836   } else {
    837     DCHECK(instr->representation().IsTagged());
    838     return DoArithmeticT(Token::ADD, instr);
    839   }
    840 }
    841 
    842 
    843 LInstruction* LChunkBuilder::DoAllocate(HAllocate* instr) {
    844   LOperand* size = UseRegisterOrConstant(instr->size());
    845   LOperand* temp1 = TempRegister();
    846   LOperand* temp2 = TempRegister();
    847   if (instr->IsAllocationFolded()) {
    848     LFastAllocate* result = new (zone()) LFastAllocate(size, temp1, temp2);
    849     return DefineAsRegister(result);
    850   } else {
    851     info()->MarkAsDeferredCalling();
    852     LOperand* context = UseAny(instr->context());
    853     LOperand* temp3 = instr->MustPrefillWithFiller() ? TempRegister() : NULL;
    854     LAllocate* result =
    855         new (zone()) LAllocate(context, size, temp1, temp2, temp3);
    856     return AssignPointerMap(DefineAsRegister(result));
    857   }
    858 }
    859 
    860 
    861 LInstruction* LChunkBuilder::DoApplyArguments(HApplyArguments* instr) {
    862   LOperand* function = UseFixed(instr->function(), x1);
    863   LOperand* receiver = UseFixed(instr->receiver(), x0);
    864   LOperand* length = UseFixed(instr->length(), x2);
    865   LOperand* elements = UseFixed(instr->elements(), x3);
    866   LApplyArguments* result = new(zone()) LApplyArguments(function,
    867                                                         receiver,
    868                                                         length,
    869                                                         elements);
    870   return MarkAsCall(DefineFixed(result, x0), instr, CAN_DEOPTIMIZE_EAGERLY);
    871 }
    872 
    873 
    874 LInstruction* LChunkBuilder::DoArgumentsElements(HArgumentsElements* instr) {
    875   info()->MarkAsRequiresFrame();
    876   LOperand* temp = instr->from_inlined() ? NULL : TempRegister();
    877   return DefineAsRegister(new(zone()) LArgumentsElements(temp));
    878 }
    879 
    880 
    881 LInstruction* LChunkBuilder::DoArgumentsLength(HArgumentsLength* instr) {
    882   info()->MarkAsRequiresFrame();
    883   LOperand* value = UseRegisterAtStart(instr->value());
    884   return DefineAsRegister(new(zone()) LArgumentsLength(value));
    885 }
    886 
    887 
    888 LInstruction* LChunkBuilder::DoArgumentsObject(HArgumentsObject* instr) {
    889   // There are no real uses of the arguments object.
    890   // arguments.length and element access are supported directly on
    891   // stack arguments, and any real arguments object use causes a bailout.
    892   // So this value is never used.
    893   return NULL;
    894 }
    895 
    896 
    897 LInstruction* LChunkBuilder::DoBitwise(HBitwise* instr) {
    898   if (instr->representation().IsSmiOrInteger32()) {
    899     DCHECK(instr->left()->representation().Equals(instr->representation()));
    900     DCHECK(instr->right()->representation().Equals(instr->representation()));
    901     DCHECK(instr->CheckFlag(HValue::kTruncatingToInt32));
    902 
    903     LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
    904     if (shifted_operation != NULL) {
    905       return shifted_operation;
    906     }
    907 
    908     LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand());
    909     LOperand* right =
    910         UseRegisterOrConstantAtStart(instr->BetterRightOperand());
    911     return instr->representation().IsSmi() ?
    912         DefineAsRegister(new(zone()) LBitS(left, right)) :
    913         DefineAsRegister(new(zone()) LBitI(left, right));
    914   } else {
    915     return DoArithmeticT(instr->op(), instr);
    916   }
    917 }
    918 
    919 
    920 LInstruction* LChunkBuilder::DoBlockEntry(HBlockEntry* instr) {
    921   // V8 expects a label to be generated for each basic block.
    922   // This is used in some places like LAllocator::IsBlockBoundary
    923   // in lithium-allocator.cc
    924   return new(zone()) LLabel(instr->block());
    925 }
    926 
    927 
    928 LInstruction* LChunkBuilder::DoBoundsCheck(HBoundsCheck* instr) {
    929   if (!FLAG_debug_code && instr->skip_check()) return NULL;
    930   LOperand* index = UseRegisterOrConstantAtStart(instr->index());
    931   LOperand* length = !index->IsConstantOperand()
    932       ? UseRegisterOrConstantAtStart(instr->length())
    933       : UseRegisterAtStart(instr->length());
    934   LInstruction* result = new(zone()) LBoundsCheck(index, length);
    935   if (!FLAG_debug_code || !instr->skip_check()) {
    936     result = AssignEnvironment(result);
    937   }
    938   return result;
    939 }
    940 
    941 
    942 LInstruction* LChunkBuilder::DoBranch(HBranch* instr) {
    943   HValue* value = instr->value();
    944   Representation r = value->representation();
    945   HType type = value->type();
    946 
    947   if (r.IsInteger32() || r.IsSmi() || r.IsDouble()) {
    948     // These representations have simple checks that cannot deoptimize.
    949     return new(zone()) LBranch(UseRegister(value), NULL, NULL);
    950   } else {
    951     DCHECK(r.IsTagged());
    952     if (type.IsBoolean() || type.IsSmi() || type.IsJSArray() ||
    953         type.IsHeapNumber()) {
    954       // These types have simple checks that cannot deoptimize.
    955       return new(zone()) LBranch(UseRegister(value), NULL, NULL);
    956     }
    957 
    958     if (type.IsString()) {
    959       // This type cannot deoptimize, but needs a scratch register.
    960       return new(zone()) LBranch(UseRegister(value), TempRegister(), NULL);
    961     }
    962 
    963     ToBooleanICStub::Types expected = instr->expected_input_types();
    964     bool needs_temps = expected.NeedsMap() || expected.IsEmpty();
    965     LOperand* temp1 = needs_temps ? TempRegister() : NULL;
    966     LOperand* temp2 = needs_temps ? TempRegister() : NULL;
    967 
    968     if (expected.IsGeneric() || expected.IsEmpty()) {
    969       // The generic case cannot deoptimize because it already supports every
    970       // possible input type.
    971       DCHECK(needs_temps);
    972       return new(zone()) LBranch(UseRegister(value), temp1, temp2);
    973     } else {
    974       return AssignEnvironment(
    975           new(zone()) LBranch(UseRegister(value), temp1, temp2));
    976     }
    977   }
    978 }
    979 
    980 
    981 LInstruction* LChunkBuilder::DoCallWithDescriptor(
    982     HCallWithDescriptor* instr) {
    983   CallInterfaceDescriptor descriptor = instr->descriptor();
    984 
    985   LOperand* target = UseRegisterOrConstantAtStart(instr->target());
    986   ZoneList<LOperand*> ops(instr->OperandCount(), zone());
    987   // Target
    988   ops.Add(target, zone());
    989   // Context
    990   LOperand* op = UseFixed(instr->OperandAt(1), cp);
    991   ops.Add(op, zone());
    992   // Other register parameters
    993   for (int i = LCallWithDescriptor::kImplicitRegisterParameterCount;
    994        i < instr->OperandCount(); i++) {
    995     op =
    996         UseFixed(instr->OperandAt(i),
    997                  descriptor.GetRegisterParameter(
    998                      i - LCallWithDescriptor::kImplicitRegisterParameterCount));
    999     ops.Add(op, zone());
   1000   }
   1001 
   1002   LCallWithDescriptor* result = new(zone()) LCallWithDescriptor(descriptor,
   1003                                                                 ops,
   1004                                                                 zone());
   1005   if (instr->syntactic_tail_call_mode() == TailCallMode::kAllow) {
   1006     result->MarkAsSyntacticTailCall();
   1007   }
   1008   return MarkAsCall(DefineFixed(result, x0), instr);
   1009 }
   1010 
   1011 
   1012 LInstruction* LChunkBuilder::DoCallNewArray(HCallNewArray* instr) {
   1013   LOperand* context = UseFixed(instr->context(), cp);
   1014   // The call to ArrayConstructCode will expect the constructor to be in x1.
   1015   LOperand* constructor = UseFixed(instr->constructor(), x1);
   1016   LCallNewArray* result = new(zone()) LCallNewArray(context, constructor);
   1017   return MarkAsCall(DefineFixed(result, x0), instr);
   1018 }
   1019 
   1020 
   1021 LInstruction* LChunkBuilder::DoCallRuntime(HCallRuntime* instr) {
   1022   LOperand* context = UseFixed(instr->context(), cp);
   1023   return MarkAsCall(DefineFixed(new(zone()) LCallRuntime(context), x0), instr);
   1024 }
   1025 
   1026 
   1027 LInstruction* LChunkBuilder::DoCapturedObject(HCapturedObject* instr) {
   1028   instr->ReplayEnvironment(current_block_->last_environment());
   1029 
   1030   // There are no real uses of a captured object.
   1031   return NULL;
   1032 }
   1033 
   1034 
   1035 LInstruction* LChunkBuilder::DoChange(HChange* instr) {
   1036   Representation from = instr->from();
   1037   Representation to = instr->to();
   1038   HValue* val = instr->value();
   1039   if (from.IsSmi()) {
   1040     if (to.IsTagged()) {
   1041       LOperand* value = UseRegister(val);
   1042       return DefineSameAsFirst(new(zone()) LDummyUse(value));
   1043     }
   1044     from = Representation::Tagged();
   1045   }
   1046   if (from.IsTagged()) {
   1047     if (to.IsDouble()) {
   1048       LOperand* value = UseRegister(val);
   1049       LOperand* temp = TempRegister();
   1050       LInstruction* result =
   1051           DefineAsRegister(new(zone()) LNumberUntagD(value, temp));
   1052       if (!val->representation().IsSmi()) result = AssignEnvironment(result);
   1053       return result;
   1054     } else if (to.IsSmi()) {
   1055       LOperand* value = UseRegister(val);
   1056       if (val->type().IsSmi()) {
   1057         return DefineSameAsFirst(new(zone()) LDummyUse(value));
   1058       }
   1059       return AssignEnvironment(DefineSameAsFirst(new(zone()) LCheckSmi(value)));
   1060     } else {
   1061       DCHECK(to.IsInteger32());
   1062       if (val->type().IsSmi() || val->representation().IsSmi()) {
   1063         LOperand* value = UseRegisterAtStart(val);
   1064         return DefineAsRegister(new(zone()) LSmiUntag(value, false));
   1065       } else {
   1066         LOperand* value = UseRegister(val);
   1067         LOperand* temp1 = TempRegister();
   1068         LOperand* temp2 = instr->CanTruncateToInt32()
   1069             ? NULL : TempDoubleRegister();
   1070         LInstruction* result =
   1071             DefineAsRegister(new(zone()) LTaggedToI(value, temp1, temp2));
   1072         if (!val->representation().IsSmi()) result = AssignEnvironment(result);
   1073         return result;
   1074       }
   1075     }
   1076   } else if (from.IsDouble()) {
   1077     if (to.IsTagged()) {
   1078       info()->MarkAsDeferredCalling();
   1079       LOperand* value = UseRegister(val);
   1080       LOperand* temp1 = TempRegister();
   1081       LOperand* temp2 = TempRegister();
   1082       LNumberTagD* result = new(zone()) LNumberTagD(value, temp1, temp2);
   1083       return AssignPointerMap(DefineAsRegister(result));
   1084     } else {
   1085       DCHECK(to.IsSmi() || to.IsInteger32());
   1086       if (instr->CanTruncateToInt32()) {
   1087         LOperand* value = UseRegister(val);
   1088         return DefineAsRegister(new(zone()) LTruncateDoubleToIntOrSmi(value));
   1089       } else {
   1090         LOperand* value = UseRegister(val);
   1091         LDoubleToIntOrSmi* result = new(zone()) LDoubleToIntOrSmi(value);
   1092         return AssignEnvironment(DefineAsRegister(result));
   1093       }
   1094     }
   1095   } else if (from.IsInteger32()) {
   1096     info()->MarkAsDeferredCalling();
   1097     if (to.IsTagged()) {
   1098       if (val->CheckFlag(HInstruction::kUint32)) {
   1099         LOperand* value = UseRegister(val);
   1100         LNumberTagU* result =
   1101             new(zone()) LNumberTagU(value, TempRegister(), TempRegister());
   1102         return AssignPointerMap(DefineAsRegister(result));
   1103       } else {
   1104         STATIC_ASSERT((kMinInt == Smi::kMinValue) &&
   1105                       (kMaxInt == Smi::kMaxValue));
   1106         LOperand* value = UseRegisterAtStart(val);
   1107         return DefineAsRegister(new(zone()) LSmiTag(value));
   1108       }
   1109     } else if (to.IsSmi()) {
   1110       LOperand* value = UseRegisterAtStart(val);
   1111       LInstruction* result = DefineAsRegister(new(zone()) LSmiTag(value));
   1112       if (instr->CheckFlag(HValue::kCanOverflow)) {
   1113         result = AssignEnvironment(result);
   1114       }
   1115       return result;
   1116     } else {
   1117       DCHECK(to.IsDouble());
   1118       if (val->CheckFlag(HInstruction::kUint32)) {
   1119         return DefineAsRegister(
   1120             new(zone()) LUint32ToDouble(UseRegisterAtStart(val)));
   1121       } else {
   1122         return DefineAsRegister(
   1123             new(zone()) LInteger32ToDouble(UseRegisterAtStart(val)));
   1124       }
   1125     }
   1126   }
   1127   UNREACHABLE();
   1128   return NULL;
   1129 }
   1130 
   1131 
   1132 LInstruction* LChunkBuilder::DoCheckValue(HCheckValue* instr) {
   1133   LOperand* value = UseRegisterAtStart(instr->value());
   1134   return AssignEnvironment(new(zone()) LCheckValue(value));
   1135 }
   1136 
   1137 
   1138 LInstruction* LChunkBuilder::DoCheckArrayBufferNotNeutered(
   1139     HCheckArrayBufferNotNeutered* instr) {
   1140   LOperand* view = UseRegisterAtStart(instr->value());
   1141   LCheckArrayBufferNotNeutered* result =
   1142       new (zone()) LCheckArrayBufferNotNeutered(view);
   1143   return AssignEnvironment(result);
   1144 }
   1145 
   1146 
   1147 LInstruction* LChunkBuilder::DoCheckInstanceType(HCheckInstanceType* instr) {
   1148   LOperand* value = UseRegisterAtStart(instr->value());
   1149   LOperand* temp = TempRegister();
   1150   LInstruction* result = new(zone()) LCheckInstanceType(value, temp);
   1151   return AssignEnvironment(result);
   1152 }
   1153 
   1154 
   1155 LInstruction* LChunkBuilder::DoCheckMaps(HCheckMaps* instr) {
   1156   if (instr->IsStabilityCheck()) return new(zone()) LCheckMaps;
   1157   LOperand* value = UseRegisterAtStart(instr->value());
   1158   LOperand* temp = TempRegister();
   1159   LInstruction* result = AssignEnvironment(new(zone()) LCheckMaps(value, temp));
   1160   if (instr->HasMigrationTarget()) {
   1161     info()->MarkAsDeferredCalling();
   1162     result = AssignPointerMap(result);
   1163   }
   1164   return result;
   1165 }
   1166 
   1167 
   1168 LInstruction* LChunkBuilder::DoCheckHeapObject(HCheckHeapObject* instr) {
   1169   LOperand* value = UseRegisterAtStart(instr->value());
   1170   LInstruction* result = new(zone()) LCheckNonSmi(value);
   1171   if (!instr->value()->type().IsHeapObject()) {
   1172     result = AssignEnvironment(result);
   1173   }
   1174   return result;
   1175 }
   1176 
   1177 
   1178 LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
   1179   LOperand* value = UseRegisterAtStart(instr->value());
   1180   return AssignEnvironment(new(zone()) LCheckSmi(value));
   1181 }
   1182 
   1183 
   1184 LInstruction* LChunkBuilder::DoClampToUint8(HClampToUint8* instr) {
   1185   HValue* value = instr->value();
   1186   Representation input_rep = value->representation();
   1187   LOperand* reg = UseRegister(value);
   1188   if (input_rep.IsDouble()) {
   1189     return DefineAsRegister(new(zone()) LClampDToUint8(reg));
   1190   } else if (input_rep.IsInteger32()) {
   1191     return DefineAsRegister(new(zone()) LClampIToUint8(reg));
   1192   } else {
   1193     DCHECK(input_rep.IsSmiOrTagged());
   1194     return AssignEnvironment(
   1195         DefineAsRegister(new(zone()) LClampTToUint8(reg,
   1196                                                     TempDoubleRegister())));
   1197   }
   1198 }
   1199 
   1200 
   1201 LInstruction* LChunkBuilder::DoClassOfTestAndBranch(
   1202     HClassOfTestAndBranch* instr) {
   1203   DCHECK(instr->value()->representation().IsTagged());
   1204   LOperand* value = UseRegisterAtStart(instr->value());
   1205   return new(zone()) LClassOfTestAndBranch(value,
   1206                                            TempRegister(),
   1207                                            TempRegister());
   1208 }
   1209 
   1210 
   1211 LInstruction* LChunkBuilder::DoCompareNumericAndBranch(
   1212     HCompareNumericAndBranch* instr) {
   1213   Representation r = instr->representation();
   1214   if (r.IsSmiOrInteger32()) {
   1215     DCHECK(instr->left()->representation().Equals(r));
   1216     DCHECK(instr->right()->representation().Equals(r));
   1217     LOperand* left = UseRegisterOrConstantAtStart(instr->left());
   1218     LOperand* right = UseRegisterOrConstantAtStart(instr->right());
   1219     return new(zone()) LCompareNumericAndBranch(left, right);
   1220   } else {
   1221     DCHECK(r.IsDouble());
   1222     DCHECK(instr->left()->representation().IsDouble());
   1223     DCHECK(instr->right()->representation().IsDouble());
   1224     if (instr->left()->IsConstant() && instr->right()->IsConstant()) {
   1225       LOperand* left = UseConstant(instr->left());
   1226       LOperand* right = UseConstant(instr->right());
   1227       return new(zone()) LCompareNumericAndBranch(left, right);
   1228     }
   1229     LOperand* left = UseRegisterAtStart(instr->left());
   1230     LOperand* right = UseRegisterAtStart(instr->right());
   1231     return new(zone()) LCompareNumericAndBranch(left, right);
   1232   }
   1233 }
   1234 
   1235 
   1236 LInstruction* LChunkBuilder::DoCompareGeneric(HCompareGeneric* instr) {
   1237   DCHECK(instr->left()->representation().IsTagged());
   1238   DCHECK(instr->right()->representation().IsTagged());
   1239   LOperand* context = UseFixed(instr->context(), cp);
   1240   LOperand* left = UseFixed(instr->left(), x1);
   1241   LOperand* right = UseFixed(instr->right(), x0);
   1242   LCmpT* result = new(zone()) LCmpT(context, left, right);
   1243   return MarkAsCall(DefineFixed(result, x0), instr);
   1244 }
   1245 
   1246 
   1247 LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
   1248     HCompareHoleAndBranch* instr) {
   1249   LOperand* value = UseRegister(instr->value());
   1250   if (instr->representation().IsTagged()) {
   1251     return new(zone()) LCmpHoleAndBranchT(value);
   1252   } else {
   1253     LOperand* temp = TempRegister();
   1254     return new(zone()) LCmpHoleAndBranchD(value, temp);
   1255   }
   1256 }
   1257 
   1258 
   1259 LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
   1260     HCompareObjectEqAndBranch* instr) {
   1261   LOperand* left = UseRegisterAtStart(instr->left());
   1262   LOperand* right = UseRegisterAtStart(instr->right());
   1263   return new(zone()) LCmpObjectEqAndBranch(left, right);
   1264 }
   1265 
   1266 
   1267 LInstruction* LChunkBuilder::DoCompareMap(HCompareMap* instr) {
   1268   DCHECK(instr->value()->representation().IsTagged());
   1269   LOperand* value = UseRegisterAtStart(instr->value());
   1270   LOperand* temp = TempRegister();
   1271   return new(zone()) LCmpMapAndBranch(value, temp);
   1272 }
   1273 
   1274 
   1275 LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
   1276   Representation r = instr->representation();
   1277   if (r.IsSmi()) {
   1278     return DefineAsRegister(new(zone()) LConstantS);
   1279   } else if (r.IsInteger32()) {
   1280     return DefineAsRegister(new(zone()) LConstantI);
   1281   } else if (r.IsDouble()) {
   1282     return DefineAsRegister(new(zone()) LConstantD);
   1283   } else if (r.IsExternal()) {
   1284     return DefineAsRegister(new(zone()) LConstantE);
   1285   } else if (r.IsTagged()) {
   1286     return DefineAsRegister(new(zone()) LConstantT);
   1287   } else {
   1288     UNREACHABLE();
   1289     return NULL;
   1290   }
   1291 }
   1292 
   1293 
   1294 LInstruction* LChunkBuilder::DoContext(HContext* instr) {
   1295   if (instr->HasNoUses()) return NULL;
   1296 
   1297   if (info()->IsStub()) {
   1298     return DefineFixed(new(zone()) LContext, cp);
   1299   }
   1300 
   1301   return DefineAsRegister(new(zone()) LContext);
   1302 }
   1303 
   1304 
   1305 LInstruction* LChunkBuilder::DoDebugBreak(HDebugBreak* instr) {
   1306   return new(zone()) LDebugBreak();
   1307 }
   1308 
   1309 
   1310 LInstruction* LChunkBuilder::DoDeclareGlobals(HDeclareGlobals* instr) {
   1311   LOperand* context = UseFixed(instr->context(), cp);
   1312   return MarkAsCall(new(zone()) LDeclareGlobals(context), instr);
   1313 }
   1314 
   1315 
   1316 LInstruction* LChunkBuilder::DoDeoptimize(HDeoptimize* instr) {
   1317   return AssignEnvironment(new(zone()) LDeoptimize);
   1318 }
   1319 
   1320 
   1321 LInstruction* LChunkBuilder::DoDivByPowerOf2I(HDiv* instr) {
   1322   DCHECK(instr->representation().IsInteger32());
   1323   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1324   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1325   LOperand* dividend = UseRegister(instr->left());
   1326   int32_t divisor = instr->right()->GetInteger32Constant();
   1327   LInstruction* result = DefineAsRegister(new(zone()) LDivByPowerOf2I(
   1328           dividend, divisor));
   1329   if ((instr->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) ||
   1330       (instr->CheckFlag(HValue::kCanOverflow) && divisor == -1) ||
   1331       (!instr->CheckFlag(HInstruction::kAllUsesTruncatingToInt32) &&
   1332        divisor != 1 && divisor != -1)) {
   1333     result = AssignEnvironment(result);
   1334   }
   1335   return result;
   1336 }
   1337 
   1338 
   1339 LInstruction* LChunkBuilder::DoDivByConstI(HDiv* instr) {
   1340   DCHECK(instr->representation().IsInteger32());
   1341   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1342   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1343   LOperand* dividend = UseRegister(instr->left());
   1344   int32_t divisor = instr->right()->GetInteger32Constant();
   1345   LOperand* temp = instr->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)
   1346       ? NULL : TempRegister();
   1347   LInstruction* result = DefineAsRegister(new(zone()) LDivByConstI(
   1348           dividend, divisor, temp));
   1349   if (divisor == 0 ||
   1350       (instr->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) ||
   1351       !instr->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
   1352     result = AssignEnvironment(result);
   1353   }
   1354   return result;
   1355 }
   1356 
   1357 
   1358 LInstruction* LChunkBuilder::DoDivI(HBinaryOperation* instr) {
   1359   DCHECK(instr->representation().IsSmiOrInteger32());
   1360   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1361   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1362   LOperand* dividend = UseRegister(instr->left());
   1363   LOperand* divisor = UseRegister(instr->right());
   1364   LOperand* temp = instr->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)
   1365       ? NULL : TempRegister();
   1366   LInstruction* result =
   1367       DefineAsRegister(new(zone()) LDivI(dividend, divisor, temp));
   1368   if (!instr->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
   1369     result = AssignEnvironment(result);
   1370   }
   1371   return result;
   1372 }
   1373 
   1374 
   1375 LInstruction* LChunkBuilder::DoDiv(HDiv* instr) {
   1376   if (instr->representation().IsSmiOrInteger32()) {
   1377     if (instr->RightIsPowerOf2()) {
   1378       return DoDivByPowerOf2I(instr);
   1379     } else if (instr->right()->IsConstant()) {
   1380       return DoDivByConstI(instr);
   1381     } else {
   1382       return DoDivI(instr);
   1383     }
   1384   } else if (instr->representation().IsDouble()) {
   1385     return DoArithmeticD(Token::DIV, instr);
   1386   } else {
   1387     return DoArithmeticT(Token::DIV, instr);
   1388   }
   1389 }
   1390 
   1391 
   1392 LInstruction* LChunkBuilder::DoDummyUse(HDummyUse* instr) {
   1393   return DefineAsRegister(new(zone()) LDummyUse(UseAny(instr->value())));
   1394 }
   1395 
   1396 
   1397 LInstruction* LChunkBuilder::DoEnterInlined(HEnterInlined* instr) {
   1398   HEnvironment* outer = current_block_->last_environment();
   1399   outer->set_ast_id(instr->ReturnId());
   1400   HConstant* undefined = graph()->GetConstantUndefined();
   1401   HEnvironment* inner = outer->CopyForInlining(
   1402       instr->closure(), instr->arguments_count(), instr->function(), undefined,
   1403       instr->inlining_kind(), instr->syntactic_tail_call_mode());
   1404   // Only replay binding of arguments object if it wasn't removed from graph.
   1405   if ((instr->arguments_var() != NULL) &&
   1406       instr->arguments_object()->IsLinked()) {
   1407     inner->Bind(instr->arguments_var(), instr->arguments_object());
   1408   }
   1409   inner->BindContext(instr->closure_context());
   1410   inner->set_entry(instr);
   1411   current_block_->UpdateEnvironment(inner);
   1412   chunk_->AddInlinedFunction(instr->shared());
   1413   return NULL;
   1414 }
   1415 
   1416 
   1417 LInstruction* LChunkBuilder::DoEnvironmentMarker(HEnvironmentMarker* instr) {
   1418   UNREACHABLE();
   1419   return NULL;
   1420 }
   1421 
   1422 
   1423 LInstruction* LChunkBuilder::DoForceRepresentation(
   1424     HForceRepresentation* instr) {
   1425   // All HForceRepresentation instructions should be eliminated in the
   1426   // representation change phase of Hydrogen.
   1427   UNREACHABLE();
   1428   return NULL;
   1429 }
   1430 
   1431 
   1432 LInstruction* LChunkBuilder::DoGetCachedArrayIndex(
   1433     HGetCachedArrayIndex* instr) {
   1434   DCHECK(instr->value()->representation().IsTagged());
   1435   LOperand* value = UseRegisterAtStart(instr->value());
   1436   return DefineAsRegister(new(zone()) LGetCachedArrayIndex(value));
   1437 }
   1438 
   1439 
   1440 LInstruction* LChunkBuilder::DoGoto(HGoto* instr) {
   1441   return new(zone()) LGoto(instr->FirstSuccessor());
   1442 }
   1443 
   1444 
   1445 LInstruction* LChunkBuilder::DoHasCachedArrayIndexAndBranch(
   1446     HHasCachedArrayIndexAndBranch* instr) {
   1447   DCHECK(instr->value()->representation().IsTagged());
   1448   return new(zone()) LHasCachedArrayIndexAndBranch(
   1449       UseRegisterAtStart(instr->value()), TempRegister());
   1450 }
   1451 
   1452 
   1453 LInstruction* LChunkBuilder::DoHasInstanceTypeAndBranch(
   1454     HHasInstanceTypeAndBranch* instr) {
   1455   DCHECK(instr->value()->representation().IsTagged());
   1456   LOperand* value = UseRegisterAtStart(instr->value());
   1457   return new(zone()) LHasInstanceTypeAndBranch(value, TempRegister());
   1458 }
   1459 
   1460 
   1461 LInstruction* LChunkBuilder::DoInnerAllocatedObject(
   1462     HInnerAllocatedObject* instr) {
   1463   LOperand* base_object = UseRegisterAtStart(instr->base_object());
   1464   LOperand* offset = UseRegisterOrConstantAtStart(instr->offset());
   1465   return DefineAsRegister(
   1466       new(zone()) LInnerAllocatedObject(base_object, offset));
   1467 }
   1468 
   1469 
   1470 LInstruction* LChunkBuilder::DoHasInPrototypeChainAndBranch(
   1471     HHasInPrototypeChainAndBranch* instr) {
   1472   LOperand* object = UseRegister(instr->object());
   1473   LOperand* prototype = UseRegister(instr->prototype());
   1474   LOperand* scratch1 = TempRegister();
   1475   LOperand* scratch2 = TempRegister();
   1476   LHasInPrototypeChainAndBranch* result = new (zone())
   1477       LHasInPrototypeChainAndBranch(object, prototype, scratch1, scratch2);
   1478   return AssignEnvironment(result);
   1479 }
   1480 
   1481 
   1482 LInstruction* LChunkBuilder::DoInvokeFunction(HInvokeFunction* instr) {
   1483   LOperand* context = UseFixed(instr->context(), cp);
   1484   // The function is required (by MacroAssembler::InvokeFunction) to be in x1.
   1485   LOperand* function = UseFixed(instr->function(), x1);
   1486   LInvokeFunction* result = new(zone()) LInvokeFunction(context, function);
   1487   if (instr->syntactic_tail_call_mode() == TailCallMode::kAllow) {
   1488     result->MarkAsSyntacticTailCall();
   1489   }
   1490   return MarkAsCall(DefineFixed(result, x0), instr, CANNOT_DEOPTIMIZE_EAGERLY);
   1491 }
   1492 
   1493 
   1494 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   1495   DCHECK(instr->value()->representation().IsTagged());
   1496   LOperand* value = UseRegisterAtStart(instr->value());
   1497   LOperand* temp = TempRegister();
   1498   return new(zone()) LIsStringAndBranch(value, temp);
   1499 }
   1500 
   1501 
   1502 LInstruction* LChunkBuilder::DoIsSmiAndBranch(HIsSmiAndBranch* instr) {
   1503   DCHECK(instr->value()->representation().IsTagged());
   1504   return new(zone()) LIsSmiAndBranch(UseRegisterAtStart(instr->value()));
   1505 }
   1506 
   1507 
   1508 LInstruction* LChunkBuilder::DoIsUndetectableAndBranch(
   1509     HIsUndetectableAndBranch* instr) {
   1510   DCHECK(instr->value()->representation().IsTagged());
   1511   LOperand* value = UseRegisterAtStart(instr->value());
   1512   return new(zone()) LIsUndetectableAndBranch(value, TempRegister());
   1513 }
   1514 
   1515 
   1516 LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
   1517   LInstruction* pop = NULL;
   1518   HEnvironment* env = current_block_->last_environment();
   1519 
   1520   if (env->entry()->arguments_pushed()) {
   1521     int argument_count = env->arguments_environment()->parameter_count();
   1522     pop = new(zone()) LDrop(argument_count);
   1523     DCHECK(instr->argument_delta() == -argument_count);
   1524   }
   1525 
   1526   HEnvironment* outer =
   1527       current_block_->last_environment()->DiscardInlined(false);
   1528   current_block_->UpdateEnvironment(outer);
   1529 
   1530   return pop;
   1531 }
   1532 
   1533 
   1534 LInstruction* LChunkBuilder::DoLoadContextSlot(HLoadContextSlot* instr) {
   1535   LOperand* context = UseRegisterAtStart(instr->value());
   1536   LInstruction* result =
   1537       DefineAsRegister(new(zone()) LLoadContextSlot(context));
   1538   if (instr->RequiresHoleCheck() && instr->DeoptimizesOnHole()) {
   1539     result = AssignEnvironment(result);
   1540   }
   1541   return result;
   1542 }
   1543 
   1544 
   1545 LInstruction* LChunkBuilder::DoLoadFunctionPrototype(
   1546     HLoadFunctionPrototype* instr) {
   1547   LOperand* function = UseRegister(instr->function());
   1548   LOperand* temp = TempRegister();
   1549   return AssignEnvironment(DefineAsRegister(
   1550       new(zone()) LLoadFunctionPrototype(function, temp)));
   1551 }
   1552 
   1553 
   1554 LInstruction* LChunkBuilder::DoLoadGlobalGeneric(HLoadGlobalGeneric* instr) {
   1555   LOperand* context = UseFixed(instr->context(), cp);
   1556   LOperand* vector = FixedTemp(LoadWithVectorDescriptor::VectorRegister());
   1557 
   1558   LLoadGlobalGeneric* result = new (zone()) LLoadGlobalGeneric(context, vector);
   1559   return MarkAsCall(DefineFixed(result, x0), instr);
   1560 }
   1561 
   1562 
   1563 LInstruction* LChunkBuilder::DoLoadKeyed(HLoadKeyed* instr) {
   1564   DCHECK(instr->key()->representation().IsSmiOrInteger32());
   1565   ElementsKind elements_kind = instr->elements_kind();
   1566   LOperand* elements = UseRegister(instr->elements());
   1567   LOperand* key = UseRegisterOrConstant(instr->key());
   1568 
   1569   if (!instr->is_fixed_typed_array()) {
   1570     if (instr->representation().IsDouble()) {
   1571       LOperand* temp = (!instr->key()->IsConstant() ||
   1572                         instr->RequiresHoleCheck())
   1573              ? TempRegister()
   1574              : NULL;
   1575       LInstruction* result = DefineAsRegister(
   1576           new (zone()) LLoadKeyedFixedDouble(elements, key, temp));
   1577       if (instr->RequiresHoleCheck()) {
   1578         result = AssignEnvironment(result);
   1579       }
   1580       return result;
   1581     } else {
   1582       DCHECK(instr->representation().IsSmiOrTagged() ||
   1583              instr->representation().IsInteger32());
   1584       LOperand* temp = instr->key()->IsConstant() ? NULL : TempRegister();
   1585       LInstruction* result =
   1586           DefineAsRegister(new (zone()) LLoadKeyedFixed(elements, key, temp));
   1587       if (instr->RequiresHoleCheck() ||
   1588           (instr->hole_mode() == CONVERT_HOLE_TO_UNDEFINED &&
   1589            info()->IsStub())) {
   1590         result = AssignEnvironment(result);
   1591       }
   1592       return result;
   1593     }
   1594   } else {
   1595     DCHECK((instr->representation().IsInteger32() &&
   1596             !IsDoubleOrFloatElementsKind(instr->elements_kind())) ||
   1597            (instr->representation().IsDouble() &&
   1598             IsDoubleOrFloatElementsKind(instr->elements_kind())));
   1599 
   1600     LOperand* temp = instr->key()->IsConstant() ? NULL : TempRegister();
   1601     LOperand* backing_store_owner = UseAny(instr->backing_store_owner());
   1602     LInstruction* result = DefineAsRegister(new (zone()) LLoadKeyedExternal(
   1603         elements, key, backing_store_owner, temp));
   1604     if (elements_kind == UINT32_ELEMENTS &&
   1605         !instr->CheckFlag(HInstruction::kUint32)) {
   1606       result = AssignEnvironment(result);
   1607     }
   1608     return result;
   1609   }
   1610 }
   1611 
   1612 
   1613 LInstruction* LChunkBuilder::DoLoadKeyedGeneric(HLoadKeyedGeneric* instr) {
   1614   LOperand* context = UseFixed(instr->context(), cp);
   1615   LOperand* object =
   1616       UseFixed(instr->object(), LoadDescriptor::ReceiverRegister());
   1617   LOperand* key = UseFixed(instr->key(), LoadDescriptor::NameRegister());
   1618   LOperand* vector = FixedTemp(LoadWithVectorDescriptor::VectorRegister());
   1619 
   1620   LInstruction* result =
   1621       DefineFixed(new(zone()) LLoadKeyedGeneric(context, object, key, vector),
   1622                   x0);
   1623   return MarkAsCall(result, instr);
   1624 }
   1625 
   1626 
   1627 LInstruction* LChunkBuilder::DoLoadNamedField(HLoadNamedField* instr) {
   1628   LOperand* object = UseRegisterAtStart(instr->object());
   1629   return DefineAsRegister(new(zone()) LLoadNamedField(object));
   1630 }
   1631 
   1632 
   1633 LInstruction* LChunkBuilder::DoLoadNamedGeneric(HLoadNamedGeneric* instr) {
   1634   LOperand* context = UseFixed(instr->context(), cp);
   1635   LOperand* object =
   1636       UseFixed(instr->object(), LoadDescriptor::ReceiverRegister());
   1637   LOperand* vector = FixedTemp(LoadWithVectorDescriptor::VectorRegister());
   1638 
   1639   LInstruction* result =
   1640       DefineFixed(new(zone()) LLoadNamedGeneric(context, object, vector), x0);
   1641   return MarkAsCall(result, instr);
   1642 }
   1643 
   1644 
   1645 LInstruction* LChunkBuilder::DoLoadRoot(HLoadRoot* instr) {
   1646   return DefineAsRegister(new(zone()) LLoadRoot);
   1647 }
   1648 
   1649 
   1650 LInstruction* LChunkBuilder::DoFlooringDivByPowerOf2I(HMathFloorOfDiv* instr) {
   1651   DCHECK(instr->representation().IsInteger32());
   1652   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1653   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1654   LOperand* dividend = UseRegisterAtStart(instr->left());
   1655   int32_t divisor = instr->right()->GetInteger32Constant();
   1656   LInstruction* result = DefineAsRegister(new(zone()) LFlooringDivByPowerOf2I(
   1657           dividend, divisor));
   1658   if ((instr->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) ||
   1659       (instr->CheckFlag(HValue::kLeftCanBeMinInt) && divisor == -1)) {
   1660     result = AssignEnvironment(result);
   1661   }
   1662   return result;
   1663 }
   1664 
   1665 
   1666 LInstruction* LChunkBuilder::DoFlooringDivByConstI(HMathFloorOfDiv* instr) {
   1667   DCHECK(instr->representation().IsInteger32());
   1668   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1669   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1670   LOperand* dividend = UseRegister(instr->left());
   1671   int32_t divisor = instr->right()->GetInteger32Constant();
   1672   LOperand* temp =
   1673       ((divisor > 0 && !instr->CheckFlag(HValue::kLeftCanBeNegative)) ||
   1674        (divisor < 0 && !instr->CheckFlag(HValue::kLeftCanBePositive))) ?
   1675       NULL : TempRegister();
   1676   LInstruction* result = DefineAsRegister(
   1677       new(zone()) LFlooringDivByConstI(dividend, divisor, temp));
   1678   if (divisor == 0 ||
   1679       (instr->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0)) {
   1680     result = AssignEnvironment(result);
   1681   }
   1682   return result;
   1683 }
   1684 
   1685 
   1686 LInstruction* LChunkBuilder::DoFlooringDivI(HMathFloorOfDiv* instr) {
   1687   LOperand* dividend = UseRegister(instr->left());
   1688   LOperand* divisor = UseRegister(instr->right());
   1689   LOperand* remainder = TempRegister();
   1690   LInstruction* result =
   1691       DefineAsRegister(new(zone()) LFlooringDivI(dividend, divisor, remainder));
   1692   return AssignEnvironment(result);
   1693 }
   1694 
   1695 
   1696 LInstruction* LChunkBuilder::DoMathFloorOfDiv(HMathFloorOfDiv* instr) {
   1697   if (instr->RightIsPowerOf2()) {
   1698     return DoFlooringDivByPowerOf2I(instr);
   1699   } else if (instr->right()->IsConstant()) {
   1700     return DoFlooringDivByConstI(instr);
   1701   } else {
   1702     return DoFlooringDivI(instr);
   1703   }
   1704 }
   1705 
   1706 
   1707 LInstruction* LChunkBuilder::DoMathMinMax(HMathMinMax* instr) {
   1708   LOperand* left = NULL;
   1709   LOperand* right = NULL;
   1710   if (instr->representation().IsSmiOrInteger32()) {
   1711     DCHECK(instr->left()->representation().Equals(instr->representation()));
   1712     DCHECK(instr->right()->representation().Equals(instr->representation()));
   1713     left = UseRegisterAtStart(instr->BetterLeftOperand());
   1714     right = UseRegisterOrConstantAtStart(instr->BetterRightOperand());
   1715   } else {
   1716     DCHECK(instr->representation().IsDouble());
   1717     DCHECK(instr->left()->representation().IsDouble());
   1718     DCHECK(instr->right()->representation().IsDouble());
   1719     left = UseRegisterAtStart(instr->left());
   1720     right = UseRegisterAtStart(instr->right());
   1721   }
   1722   return DefineAsRegister(new(zone()) LMathMinMax(left, right));
   1723 }
   1724 
   1725 
   1726 LInstruction* LChunkBuilder::DoModByPowerOf2I(HMod* instr) {
   1727   DCHECK(instr->representation().IsInteger32());
   1728   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1729   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1730   LOperand* dividend = UseRegisterAtStart(instr->left());
   1731   int32_t divisor = instr->right()->GetInteger32Constant();
   1732   LInstruction* result = DefineSameAsFirst(new(zone()) LModByPowerOf2I(
   1733           dividend, divisor));
   1734   if (instr->CheckFlag(HValue::kLeftCanBeNegative) &&
   1735       instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1736     result = AssignEnvironment(result);
   1737   }
   1738   return result;
   1739 }
   1740 
   1741 
   1742 LInstruction* LChunkBuilder::DoModByConstI(HMod* instr) {
   1743   DCHECK(instr->representation().IsInteger32());
   1744   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1745   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1746   LOperand* dividend = UseRegister(instr->left());
   1747   int32_t divisor = instr->right()->GetInteger32Constant();
   1748   LOperand* temp = TempRegister();
   1749   LInstruction* result = DefineAsRegister(new(zone()) LModByConstI(
   1750           dividend, divisor, temp));
   1751   if (divisor == 0 || instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1752     result = AssignEnvironment(result);
   1753   }
   1754   return result;
   1755 }
   1756 
   1757 
   1758 LInstruction* LChunkBuilder::DoModI(HMod* instr) {
   1759   DCHECK(instr->representation().IsSmiOrInteger32());
   1760   DCHECK(instr->left()->representation().Equals(instr->representation()));
   1761   DCHECK(instr->right()->representation().Equals(instr->representation()));
   1762   LOperand* dividend = UseRegister(instr->left());
   1763   LOperand* divisor = UseRegister(instr->right());
   1764   LInstruction* result = DefineAsRegister(new(zone()) LModI(dividend, divisor));
   1765   if (instr->CheckFlag(HValue::kCanBeDivByZero) ||
   1766       instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1767     result = AssignEnvironment(result);
   1768   }
   1769   return result;
   1770 }
   1771 
   1772 
   1773 LInstruction* LChunkBuilder::DoMod(HMod* instr) {
   1774   if (instr->representation().IsSmiOrInteger32()) {
   1775     if (instr->RightIsPowerOf2()) {
   1776       return DoModByPowerOf2I(instr);
   1777     } else if (instr->right()->IsConstant()) {
   1778       return DoModByConstI(instr);
   1779     } else {
   1780       return DoModI(instr);
   1781     }
   1782   } else if (instr->representation().IsDouble()) {
   1783     return DoArithmeticD(Token::MOD, instr);
   1784   } else {
   1785     return DoArithmeticT(Token::MOD, instr);
   1786   }
   1787 }
   1788 
   1789 
   1790 LInstruction* LChunkBuilder::DoMul(HMul* instr) {
   1791   if (instr->representation().IsSmiOrInteger32()) {
   1792     DCHECK(instr->left()->representation().Equals(instr->representation()));
   1793     DCHECK(instr->right()->representation().Equals(instr->representation()));
   1794 
   1795     bool can_overflow = instr->CheckFlag(HValue::kCanOverflow);
   1796     bool bailout_on_minus_zero = instr->CheckFlag(HValue::kBailoutOnMinusZero);
   1797 
   1798     HValue* least_const = instr->BetterLeftOperand();
   1799     HValue* most_const = instr->BetterRightOperand();
   1800 
   1801     // LMulConstI can handle a subset of constants:
   1802     //  With support for overflow detection:
   1803     //    -1, 0, 1, 2
   1804     //    2^n, -(2^n)
   1805     //  Without support for overflow detection:
   1806     //    2^n + 1, -(2^n - 1)
   1807     if (most_const->IsConstant()) {
   1808       int32_t constant = HConstant::cast(most_const)->Integer32Value();
   1809       bool small_constant = (constant >= -1) && (constant <= 2);
   1810       bool end_range_constant = (constant <= -kMaxInt) || (constant == kMaxInt);
   1811       int32_t constant_abs = Abs(constant);
   1812 
   1813       if (!end_range_constant &&
   1814           (small_constant || (base::bits::IsPowerOfTwo32(constant_abs)) ||
   1815            (!can_overflow && (base::bits::IsPowerOfTwo32(constant_abs + 1) ||
   1816                               base::bits::IsPowerOfTwo32(constant_abs - 1))))) {
   1817         LConstantOperand* right = UseConstant(most_const);
   1818         bool need_register =
   1819             base::bits::IsPowerOfTwo32(constant_abs) && !small_constant;
   1820         LOperand* left = need_register ? UseRegister(least_const)
   1821                                        : UseRegisterAtStart(least_const);
   1822         LInstruction* result =
   1823             DefineAsRegister(new(zone()) LMulConstIS(left, right));
   1824         if ((bailout_on_minus_zero && constant <= 0) ||
   1825             (can_overflow && constant != 1 &&
   1826              base::bits::IsPowerOfTwo32(constant_abs))) {
   1827           result = AssignEnvironment(result);
   1828         }
   1829         return result;
   1830       }
   1831     }
   1832 
   1833     // LMulI/S can handle all cases, but it requires that a register is
   1834     // allocated for the second operand.
   1835     LOperand* left = UseRegisterAtStart(least_const);
   1836     LOperand* right = UseRegisterAtStart(most_const);
   1837     LInstruction* result = instr->representation().IsSmi()
   1838         ? DefineAsRegister(new(zone()) LMulS(left, right))
   1839         : DefineAsRegister(new(zone()) LMulI(left, right));
   1840     if ((bailout_on_minus_zero && least_const != most_const) || can_overflow) {
   1841       result = AssignEnvironment(result);
   1842     }
   1843     return result;
   1844   } else if (instr->representation().IsDouble()) {
   1845     return DoArithmeticD(Token::MUL, instr);
   1846   } else {
   1847     return DoArithmeticT(Token::MUL, instr);
   1848   }
   1849 }
   1850 
   1851 
   1852 LInstruction* LChunkBuilder::DoOsrEntry(HOsrEntry* instr) {
   1853   DCHECK(argument_count_ == 0);
   1854   allocator_->MarkAsOsrEntry();
   1855   current_block_->last_environment()->set_ast_id(instr->ast_id());
   1856   return AssignEnvironment(new(zone()) LOsrEntry);
   1857 }
   1858 
   1859 
   1860 LInstruction* LChunkBuilder::DoParameter(HParameter* instr) {
   1861   LParameter* result = new(zone()) LParameter;
   1862   if (instr->kind() == HParameter::STACK_PARAMETER) {
   1863     int spill_index = chunk_->GetParameterStackSlot(instr->index());
   1864     return DefineAsSpilled(result, spill_index);
   1865   } else {
   1866     DCHECK(info()->IsStub());
   1867     CallInterfaceDescriptor descriptor = graph()->descriptor();
   1868     int index = static_cast<int>(instr->index());
   1869     Register reg = descriptor.GetRegisterParameter(index);
   1870     return DefineFixed(result, reg);
   1871   }
   1872 }
   1873 
   1874 
   1875 LInstruction* LChunkBuilder::DoPower(HPower* instr) {
   1876   DCHECK(instr->representation().IsDouble());
   1877   // We call a C function for double power. It can't trigger a GC.
   1878   // We need to use fixed result register for the call.
   1879   Representation exponent_type = instr->right()->representation();
   1880   DCHECK(instr->left()->representation().IsDouble());
   1881   LOperand* left = UseFixedDouble(instr->left(), d0);
   1882   LOperand* right;
   1883   if (exponent_type.IsInteger32()) {
   1884     right = UseFixed(instr->right(), MathPowIntegerDescriptor::exponent());
   1885   } else if (exponent_type.IsDouble()) {
   1886     right = UseFixedDouble(instr->right(), d1);
   1887   } else {
   1888     right = UseFixed(instr->right(), MathPowTaggedDescriptor::exponent());
   1889   }
   1890   LPower* result = new(zone()) LPower(left, right);
   1891   return MarkAsCall(DefineFixedDouble(result, d0),
   1892                     instr,
   1893                     CAN_DEOPTIMIZE_EAGERLY);
   1894 }
   1895 
   1896 
   1897 LInstruction* LChunkBuilder::DoPushArguments(HPushArguments* instr) {
   1898   int argc = instr->OperandCount();
   1899   AddInstruction(new(zone()) LPreparePushArguments(argc), instr);
   1900 
   1901   LPushArguments* push_args = new(zone()) LPushArguments(zone());
   1902 
   1903   for (int i = 0; i < argc; ++i) {
   1904     if (push_args->ShouldSplitPush()) {
   1905       AddInstruction(push_args, instr);
   1906       push_args = new(zone()) LPushArguments(zone());
   1907     }
   1908     push_args->AddArgument(UseRegister(instr->argument(i)));
   1909   }
   1910 
   1911   return push_args;
   1912 }
   1913 
   1914 
   1915 LInstruction* LChunkBuilder::DoDoubleBits(HDoubleBits* instr) {
   1916   HValue* value = instr->value();
   1917   DCHECK(value->representation().IsDouble());
   1918   return DefineAsRegister(new(zone()) LDoubleBits(UseRegister(value)));
   1919 }
   1920 
   1921 
   1922 LInstruction* LChunkBuilder::DoReturn(HReturn* instr) {
   1923   LOperand* context = info()->IsStub()
   1924       ? UseFixed(instr->context(), cp)
   1925       : NULL;
   1926   LOperand* parameter_count = UseRegisterOrConstant(instr->parameter_count());
   1927   return new(zone()) LReturn(UseFixed(instr->value(), x0), context,
   1928                              parameter_count);
   1929 }
   1930 
   1931 
   1932 LInstruction* LChunkBuilder::DoSeqStringGetChar(HSeqStringGetChar* instr) {
   1933   LOperand* string = UseRegisterAtStart(instr->string());
   1934   LOperand* index = UseRegisterOrConstantAtStart(instr->index());
   1935   LOperand* temp = TempRegister();
   1936   LSeqStringGetChar* result =
   1937       new(zone()) LSeqStringGetChar(string, index, temp);
   1938   return DefineAsRegister(result);
   1939 }
   1940 
   1941 
   1942 LInstruction* LChunkBuilder::DoSeqStringSetChar(HSeqStringSetChar* instr) {
   1943   LOperand* string = UseRegister(instr->string());
   1944   LOperand* index = FLAG_debug_code
   1945       ? UseRegister(instr->index())
   1946       : UseRegisterOrConstant(instr->index());
   1947   LOperand* value = UseRegister(instr->value());
   1948   LOperand* context = FLAG_debug_code ? UseFixed(instr->context(), cp) : NULL;
   1949   LOperand* temp = TempRegister();
   1950   LSeqStringSetChar* result =
   1951       new(zone()) LSeqStringSetChar(context, string, index, value, temp);
   1952   return DefineAsRegister(result);
   1953 }
   1954 
   1955 
   1956 HBitwiseBinaryOperation* LChunkBuilder::CanTransformToShiftedOp(HValue* val,
   1957                                                                 HValue** left) {
   1958   if (!val->representation().IsInteger32()) return NULL;
   1959   if (!(val->IsBitwise() || val->IsAdd() || val->IsSub())) return NULL;
   1960 
   1961   HBinaryOperation* hinstr = HBinaryOperation::cast(val);
   1962   HValue* hleft = hinstr->left();
   1963   HValue* hright = hinstr->right();
   1964   DCHECK(hleft->representation().Equals(hinstr->representation()));
   1965   DCHECK(hright->representation().Equals(hinstr->representation()));
   1966 
   1967   if (hleft == hright) return NULL;
   1968 
   1969   if ((hright->IsConstant() &&
   1970        LikelyFitsImmField(hinstr, HConstant::cast(hright)->Integer32Value())) ||
   1971       (hinstr->IsCommutative() && hleft->IsConstant() &&
   1972        LikelyFitsImmField(hinstr, HConstant::cast(hleft)->Integer32Value()))) {
   1973     // The constant operand will likely fit in the immediate field. We are
   1974     // better off with
   1975     //     lsl x8, x9, #imm
   1976     //     add x0, x8, #imm2
   1977     // than with
   1978     //     mov x16, #imm2
   1979     //     add x0, x16, x9 LSL #imm
   1980     return NULL;
   1981   }
   1982 
   1983   HBitwiseBinaryOperation* shift = NULL;
   1984   // TODO(aleram): We will miss situations where a shift operation is used by
   1985   // different instructions both as a left and right operands.
   1986   if (hright->IsBitwiseBinaryShift() &&
   1987       HBitwiseBinaryOperation::cast(hright)->right()->IsConstant()) {
   1988     shift = HBitwiseBinaryOperation::cast(hright);
   1989     if (left != NULL) {
   1990       *left = hleft;
   1991     }
   1992   } else if (hinstr->IsCommutative() &&
   1993              hleft->IsBitwiseBinaryShift() &&
   1994              HBitwiseBinaryOperation::cast(hleft)->right()->IsConstant()) {
   1995     shift = HBitwiseBinaryOperation::cast(hleft);
   1996     if (left != NULL) {
   1997       *left = hright;
   1998     }
   1999   } else {
   2000     return NULL;
   2001   }
   2002 
   2003   if ((JSShiftAmountFromHConstant(shift->right()) == 0) && shift->IsShr()) {
   2004     // Shifts right by zero can deoptimize.
   2005     return NULL;
   2006   }
   2007 
   2008   return shift;
   2009 }
   2010 
   2011 
   2012 bool LChunkBuilder::ShiftCanBeOptimizedAway(HBitwiseBinaryOperation* shift) {
   2013   if (!shift->representation().IsInteger32()) {
   2014     return false;
   2015   }
   2016   for (HUseIterator it(shift->uses()); !it.Done(); it.Advance()) {
   2017     if (shift != CanTransformToShiftedOp(it.value())) {
   2018       return false;
   2019     }
   2020   }
   2021   return true;
   2022 }
   2023 
   2024 
   2025 LInstruction* LChunkBuilder::TryDoOpWithShiftedRightOperand(
   2026     HBinaryOperation* instr) {
   2027   HValue* left;
   2028   HBitwiseBinaryOperation* shift = CanTransformToShiftedOp(instr, &left);
   2029 
   2030   if ((shift != NULL) && ShiftCanBeOptimizedAway(shift)) {
   2031     return DoShiftedBinaryOp(instr, left, shift);
   2032   }
   2033   return NULL;
   2034 }
   2035 
   2036 
   2037 LInstruction* LChunkBuilder::DoShiftedBinaryOp(
   2038     HBinaryOperation* hinstr, HValue* hleft, HBitwiseBinaryOperation* hshift) {
   2039   DCHECK(hshift->IsBitwiseBinaryShift());
   2040   DCHECK(!hshift->IsShr() || (JSShiftAmountFromHConstant(hshift->right()) > 0));
   2041 
   2042   LTemplateResultInstruction<1>* res;
   2043   LOperand* left = UseRegisterAtStart(hleft);
   2044   LOperand* right = UseRegisterAtStart(hshift->left());
   2045   LOperand* shift_amount = UseConstant(hshift->right());
   2046   Shift shift_op;
   2047   switch (hshift->opcode()) {
   2048     case HValue::kShl: shift_op = LSL; break;
   2049     case HValue::kShr: shift_op = LSR; break;
   2050     case HValue::kSar: shift_op = ASR; break;
   2051     default: UNREACHABLE(); shift_op = NO_SHIFT;
   2052   }
   2053 
   2054   if (hinstr->IsBitwise()) {
   2055     res = new(zone()) LBitI(left, right, shift_op, shift_amount);
   2056   } else if (hinstr->IsAdd()) {
   2057     res = new(zone()) LAddI(left, right, shift_op, shift_amount);
   2058   } else {
   2059     DCHECK(hinstr->IsSub());
   2060     res = new(zone()) LSubI(left, right, shift_op, shift_amount);
   2061   }
   2062   if (hinstr->CheckFlag(HValue::kCanOverflow)) {
   2063     AssignEnvironment(res);
   2064   }
   2065   return DefineAsRegister(res);
   2066 }
   2067 
   2068 
   2069 LInstruction* LChunkBuilder::DoShift(Token::Value op,
   2070                                      HBitwiseBinaryOperation* instr) {
   2071   if (instr->representation().IsTagged()) {
   2072     return DoArithmeticT(op, instr);
   2073   }
   2074 
   2075   DCHECK(instr->representation().IsSmiOrInteger32());
   2076   DCHECK(instr->left()->representation().Equals(instr->representation()));
   2077   DCHECK(instr->right()->representation().Equals(instr->representation()));
   2078 
   2079   if (ShiftCanBeOptimizedAway(instr)) {
   2080     return NULL;
   2081   }
   2082 
   2083   LOperand* left = instr->representation().IsSmi()
   2084       ? UseRegister(instr->left())
   2085       : UseRegisterAtStart(instr->left());
   2086   LOperand* right = UseRegisterOrConstantAtStart(instr->right());
   2087 
   2088   // The only shift that can deoptimize is `left >>> 0`, where left is negative.
   2089   // In these cases, the result is a uint32 that is too large for an int32.
   2090   bool right_can_be_zero = !instr->right()->IsConstant() ||
   2091                            (JSShiftAmountFromHConstant(instr->right()) == 0);
   2092   bool can_deopt = false;
   2093   if ((op == Token::SHR) && right_can_be_zero) {
   2094     can_deopt = !instr->CheckFlag(HInstruction::kUint32);
   2095   }
   2096 
   2097   LInstruction* result;
   2098   if (instr->representation().IsInteger32()) {
   2099     result = DefineAsRegister(new (zone()) LShiftI(op, left, right, can_deopt));
   2100   } else {
   2101     DCHECK(instr->representation().IsSmi());
   2102     result = DefineAsRegister(new (zone()) LShiftS(op, left, right, can_deopt));
   2103   }
   2104 
   2105   return can_deopt ? AssignEnvironment(result) : result;
   2106 }
   2107 
   2108 
   2109 LInstruction* LChunkBuilder::DoRor(HRor* instr) {
   2110   return DoShift(Token::ROR, instr);
   2111 }
   2112 
   2113 
   2114 LInstruction* LChunkBuilder::DoSar(HSar* instr) {
   2115   return DoShift(Token::SAR, instr);
   2116 }
   2117 
   2118 
   2119 LInstruction* LChunkBuilder::DoShl(HShl* instr) {
   2120   return DoShift(Token::SHL, instr);
   2121 }
   2122 
   2123 
   2124 LInstruction* LChunkBuilder::DoShr(HShr* instr) {
   2125   return DoShift(Token::SHR, instr);
   2126 }
   2127 
   2128 
   2129 LInstruction* LChunkBuilder::DoSimulate(HSimulate* instr) {
   2130   instr->ReplayEnvironment(current_block_->last_environment());
   2131   return NULL;
   2132 }
   2133 
   2134 
   2135 LInstruction* LChunkBuilder::DoStackCheck(HStackCheck* instr) {
   2136   if (instr->is_function_entry()) {
   2137     LOperand* context = UseFixed(instr->context(), cp);
   2138     return MarkAsCall(new(zone()) LStackCheck(context), instr);
   2139   } else {
   2140     DCHECK(instr->is_backwards_branch());
   2141     LOperand* context = UseAny(instr->context());
   2142     return AssignEnvironment(
   2143         AssignPointerMap(new(zone()) LStackCheck(context)));
   2144   }
   2145 }
   2146 
   2147 
   2148 LInstruction* LChunkBuilder::DoStoreCodeEntry(HStoreCodeEntry* instr) {
   2149   LOperand* function = UseRegister(instr->function());
   2150   LOperand* code_object = UseRegisterAtStart(instr->code_object());
   2151   LOperand* temp = TempRegister();
   2152   return new(zone()) LStoreCodeEntry(function, code_object, temp);
   2153 }
   2154 
   2155 
   2156 LInstruction* LChunkBuilder::DoStoreContextSlot(HStoreContextSlot* instr) {
   2157   LOperand* temp = TempRegister();
   2158   LOperand* context;
   2159   LOperand* value;
   2160   if (instr->NeedsWriteBarrier()) {
   2161     // TODO(all): Replace these constraints when RecordWriteStub has been
   2162     // rewritten.
   2163     context = UseRegisterAndClobber(instr->context());
   2164     value = UseRegisterAndClobber(instr->value());
   2165   } else {
   2166     context = UseRegister(instr->context());
   2167     value = UseRegister(instr->value());
   2168   }
   2169   LInstruction* result = new(zone()) LStoreContextSlot(context, value, temp);
   2170   if (instr->RequiresHoleCheck() && instr->DeoptimizesOnHole()) {
   2171     result = AssignEnvironment(result);
   2172   }
   2173   return result;
   2174 }
   2175 
   2176 
   2177 LInstruction* LChunkBuilder::DoStoreKeyed(HStoreKeyed* instr) {
   2178   LOperand* key = UseRegisterOrConstant(instr->key());
   2179   LOperand* temp = NULL;
   2180   LOperand* elements = NULL;
   2181   LOperand* val = NULL;
   2182 
   2183   if (!instr->is_fixed_typed_array() &&
   2184       instr->value()->representation().IsTagged() &&
   2185       instr->NeedsWriteBarrier()) {
   2186     // RecordWrite() will clobber all registers.
   2187     elements = UseRegisterAndClobber(instr->elements());
   2188     val = UseRegisterAndClobber(instr->value());
   2189     temp = TempRegister();
   2190   } else {
   2191     elements = UseRegister(instr->elements());
   2192     val = UseRegister(instr->value());
   2193     temp = instr->key()->IsConstant() ? NULL : TempRegister();
   2194   }
   2195 
   2196   if (instr->is_fixed_typed_array()) {
   2197     DCHECK((instr->value()->representation().IsInteger32() &&
   2198             !IsDoubleOrFloatElementsKind(instr->elements_kind())) ||
   2199            (instr->value()->representation().IsDouble() &&
   2200             IsDoubleOrFloatElementsKind(instr->elements_kind())));
   2201     DCHECK(instr->elements()->representation().IsExternal());
   2202     LOperand* backing_store_owner = UseAny(instr->backing_store_owner());
   2203     return new (zone())
   2204         LStoreKeyedExternal(elements, key, val, backing_store_owner, temp);
   2205 
   2206   } else if (instr->value()->representation().IsDouble()) {
   2207     DCHECK(instr->elements()->representation().IsTagged());
   2208     return new(zone()) LStoreKeyedFixedDouble(elements, key, val, temp);
   2209 
   2210   } else {
   2211     DCHECK(instr->elements()->representation().IsTagged());
   2212     DCHECK(instr->value()->representation().IsSmiOrTagged() ||
   2213            instr->value()->representation().IsInteger32());
   2214     return new(zone()) LStoreKeyedFixed(elements, key, val, temp);
   2215   }
   2216 }
   2217 
   2218 
   2219 LInstruction* LChunkBuilder::DoStoreKeyedGeneric(HStoreKeyedGeneric* instr) {
   2220   LOperand* context = UseFixed(instr->context(), cp);
   2221   LOperand* object =
   2222       UseFixed(instr->object(), StoreDescriptor::ReceiverRegister());
   2223   LOperand* key = UseFixed(instr->key(), StoreDescriptor::NameRegister());
   2224   LOperand* value = UseFixed(instr->value(), StoreDescriptor::ValueRegister());
   2225 
   2226   DCHECK(instr->object()->representation().IsTagged());
   2227   DCHECK(instr->key()->representation().IsTagged());
   2228   DCHECK(instr->value()->representation().IsTagged());
   2229 
   2230   LOperand* slot = FixedTemp(VectorStoreICDescriptor::SlotRegister());
   2231   LOperand* vector = FixedTemp(VectorStoreICDescriptor::VectorRegister());
   2232 
   2233   LStoreKeyedGeneric* result = new (zone())
   2234       LStoreKeyedGeneric(context, object, key, value, slot, vector);
   2235   return MarkAsCall(result, instr);
   2236 }
   2237 
   2238 
   2239 LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
   2240   // TODO(jbramley): It might be beneficial to allow value to be a constant in
   2241   // some cases. x64 makes use of this with FLAG_track_fields, for example.
   2242 
   2243   LOperand* object = UseRegister(instr->object());
   2244   LOperand* value;
   2245   LOperand* temp0 = NULL;
   2246   LOperand* temp1 = NULL;
   2247 
   2248   if (instr->access().IsExternalMemory() ||
   2249       (!FLAG_unbox_double_fields && instr->field_representation().IsDouble())) {
   2250     value = UseRegister(instr->value());
   2251   } else if (instr->NeedsWriteBarrier()) {
   2252     value = UseRegisterAndClobber(instr->value());
   2253     temp0 = TempRegister();
   2254     temp1 = TempRegister();
   2255   } else if (instr->NeedsWriteBarrierForMap()) {
   2256     value = UseRegister(instr->value());
   2257     temp0 = TempRegister();
   2258     temp1 = TempRegister();
   2259   } else {
   2260     value = UseRegister(instr->value());
   2261     temp0 = TempRegister();
   2262   }
   2263 
   2264   return new(zone()) LStoreNamedField(object, value, temp0, temp1);
   2265 }
   2266 
   2267 
   2268 LInstruction* LChunkBuilder::DoStoreNamedGeneric(HStoreNamedGeneric* instr) {
   2269   LOperand* context = UseFixed(instr->context(), cp);
   2270   LOperand* object =
   2271       UseFixed(instr->object(), StoreDescriptor::ReceiverRegister());
   2272   LOperand* value = UseFixed(instr->value(), StoreDescriptor::ValueRegister());
   2273 
   2274   LOperand* slot = FixedTemp(VectorStoreICDescriptor::SlotRegister());
   2275   LOperand* vector = FixedTemp(VectorStoreICDescriptor::VectorRegister());
   2276 
   2277   LStoreNamedGeneric* result =
   2278       new (zone()) LStoreNamedGeneric(context, object, value, slot, vector);
   2279   return MarkAsCall(result, instr);
   2280 }
   2281 
   2282 
   2283 LInstruction* LChunkBuilder::DoStringAdd(HStringAdd* instr) {
   2284   LOperand* context = UseFixed(instr->context(), cp);
   2285   LOperand* left = UseFixed(instr->left(), x1);
   2286   LOperand* right = UseFixed(instr->right(), x0);
   2287 
   2288   LStringAdd* result = new(zone()) LStringAdd(context, left, right);
   2289   return MarkAsCall(DefineFixed(result, x0), instr);
   2290 }
   2291 
   2292 
   2293 LInstruction* LChunkBuilder::DoStringCharCodeAt(HStringCharCodeAt* instr) {
   2294   LOperand* string = UseRegisterAndClobber(instr->string());
   2295   LOperand* index = UseRegisterAndClobber(instr->index());
   2296   LOperand* context = UseAny(instr->context());
   2297   LStringCharCodeAt* result =
   2298       new(zone()) LStringCharCodeAt(context, string, index);
   2299   return AssignPointerMap(DefineAsRegister(result));
   2300 }
   2301 
   2302 
   2303 LInstruction* LChunkBuilder::DoStringCharFromCode(HStringCharFromCode* instr) {
   2304   LOperand* char_code = UseRegister(instr->value());
   2305   LOperand* context = UseAny(instr->context());
   2306   LStringCharFromCode* result =
   2307       new(zone()) LStringCharFromCode(context, char_code);
   2308   return AssignPointerMap(DefineAsRegister(result));
   2309 }
   2310 
   2311 
   2312 LInstruction* LChunkBuilder::DoStringCompareAndBranch(
   2313     HStringCompareAndBranch* instr) {
   2314   DCHECK(instr->left()->representation().IsTagged());
   2315   DCHECK(instr->right()->representation().IsTagged());
   2316   LOperand* context = UseFixed(instr->context(), cp);
   2317   LOperand* left = UseFixed(instr->left(), x1);
   2318   LOperand* right = UseFixed(instr->right(), x0);
   2319   LStringCompareAndBranch* result =
   2320       new(zone()) LStringCompareAndBranch(context, left, right);
   2321   return MarkAsCall(result, instr);
   2322 }
   2323 
   2324 
   2325 LInstruction* LChunkBuilder::DoSub(HSub* instr) {
   2326   if (instr->representation().IsSmiOrInteger32()) {
   2327     DCHECK(instr->left()->representation().Equals(instr->representation()));
   2328     DCHECK(instr->right()->representation().Equals(instr->representation()));
   2329 
   2330     LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
   2331     if (shifted_operation != NULL) {
   2332       return shifted_operation;
   2333     }
   2334 
   2335     LOperand *left;
   2336     if (instr->left()->IsConstant() &&
   2337         (HConstant::cast(instr->left())->Integer32Value() == 0)) {
   2338       left = UseConstant(instr->left());
   2339     } else {
   2340       left = UseRegisterAtStart(instr->left());
   2341     }
   2342     LOperand* right = UseRegisterOrConstantAtStart(instr->right());
   2343     LInstruction* result = instr->representation().IsSmi() ?
   2344         DefineAsRegister(new(zone()) LSubS(left, right)) :
   2345         DefineAsRegister(new(zone()) LSubI(left, right));
   2346     if (instr->CheckFlag(HValue::kCanOverflow)) {
   2347       result = AssignEnvironment(result);
   2348     }
   2349     return result;
   2350   } else if (instr->representation().IsDouble()) {
   2351     return DoArithmeticD(Token::SUB, instr);
   2352   } else {
   2353     return DoArithmeticT(Token::SUB, instr);
   2354   }
   2355 }
   2356 
   2357 
   2358 LInstruction* LChunkBuilder::DoThisFunction(HThisFunction* instr) {
   2359   if (instr->HasNoUses()) {
   2360     return NULL;
   2361   } else {
   2362     return DefineAsRegister(new(zone()) LThisFunction);
   2363   }
   2364 }
   2365 
   2366 
   2367 LInstruction* LChunkBuilder::DoTransitionElementsKind(
   2368     HTransitionElementsKind* instr) {
   2369   if (IsSimpleMapChangeTransition(instr->from_kind(), instr->to_kind())) {
   2370     LOperand* object = UseRegister(instr->object());
   2371     LTransitionElementsKind* result =
   2372         new(zone()) LTransitionElementsKind(object, NULL,
   2373                                             TempRegister(), TempRegister());
   2374     return result;
   2375   } else {
   2376     LOperand* object = UseFixed(instr->object(), x0);
   2377     LOperand* context = UseFixed(instr->context(), cp);
   2378     LTransitionElementsKind* result =
   2379         new(zone()) LTransitionElementsKind(object, context, NULL, NULL);
   2380     return MarkAsCall(result, instr);
   2381   }
   2382 }
   2383 
   2384 
   2385 LInstruction* LChunkBuilder::DoTrapAllocationMemento(
   2386     HTrapAllocationMemento* instr) {
   2387   LOperand* object = UseRegister(instr->object());
   2388   LOperand* temp1 = TempRegister();
   2389   LOperand* temp2 = TempRegister();
   2390   LTrapAllocationMemento* result =
   2391       new(zone()) LTrapAllocationMemento(object, temp1, temp2);
   2392   return AssignEnvironment(result);
   2393 }
   2394 
   2395 
   2396 LInstruction* LChunkBuilder::DoMaybeGrowElements(HMaybeGrowElements* instr) {
   2397   info()->MarkAsDeferredCalling();
   2398   LOperand* context = UseFixed(instr->context(), cp);
   2399   LOperand* object = UseRegister(instr->object());
   2400   LOperand* elements = UseRegister(instr->elements());
   2401   LOperand* key = UseRegisterOrConstant(instr->key());
   2402   LOperand* current_capacity = UseRegisterOrConstant(instr->current_capacity());
   2403 
   2404   LMaybeGrowElements* result = new (zone())
   2405       LMaybeGrowElements(context, object, elements, key, current_capacity);
   2406   DefineFixed(result, x0);
   2407   return AssignPointerMap(AssignEnvironment(result));
   2408 }
   2409 
   2410 
   2411 LInstruction* LChunkBuilder::DoTypeof(HTypeof* instr) {
   2412   LOperand* context = UseFixed(instr->context(), cp);
   2413   LOperand* value = UseFixed(instr->value(), x3);
   2414   LTypeof* result = new (zone()) LTypeof(context, value);
   2415   return MarkAsCall(DefineFixed(result, x0), instr);
   2416 }
   2417 
   2418 
   2419 LInstruction* LChunkBuilder::DoTypeofIsAndBranch(HTypeofIsAndBranch* instr) {
   2420   // We only need temp registers in some cases, but we can't dereference the
   2421   // instr->type_literal() handle to test that here.
   2422   LOperand* temp1 = TempRegister();
   2423   LOperand* temp2 = TempRegister();
   2424 
   2425   return new(zone()) LTypeofIsAndBranch(
   2426       UseRegister(instr->value()), temp1, temp2);
   2427 }
   2428 
   2429 
   2430 LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
   2431   switch (instr->op()) {
   2432     case kMathAbs: {
   2433       Representation r = instr->representation();
   2434       if (r.IsTagged()) {
   2435         // The tagged case might need to allocate a HeapNumber for the result,
   2436         // so it is handled by a separate LInstruction.
   2437         LOperand* context = UseFixed(instr->context(), cp);
   2438         LOperand* input = UseRegister(instr->value());
   2439         LOperand* temp1 = TempRegister();
   2440         LOperand* temp2 = TempRegister();
   2441         LOperand* temp3 = TempRegister();
   2442         LInstruction* result = DefineAsRegister(
   2443             new(zone()) LMathAbsTagged(context, input, temp1, temp2, temp3));
   2444         return AssignEnvironment(AssignPointerMap(result));
   2445       } else {
   2446         LOperand* input = UseRegisterAtStart(instr->value());
   2447         LInstruction* result = DefineAsRegister(new(zone()) LMathAbs(input));
   2448         if (!r.IsDouble()) result = AssignEnvironment(result);
   2449         return result;
   2450       }
   2451     }
   2452     case kMathCos: {
   2453       DCHECK(instr->representation().IsDouble());
   2454       DCHECK(instr->value()->representation().IsDouble());
   2455       LOperand* input = UseFixedDouble(instr->value(), d0);
   2456       LMathCos* result = new (zone()) LMathCos(input);
   2457       return MarkAsCall(DefineFixedDouble(result, d0), instr);
   2458     }
   2459     case kMathSin: {
   2460       DCHECK(instr->representation().IsDouble());
   2461       DCHECK(instr->value()->representation().IsDouble());
   2462       LOperand* input = UseFixedDouble(instr->value(), d0);
   2463       LMathSin* result = new (zone()) LMathSin(input);
   2464       return MarkAsCall(DefineFixedDouble(result, d0), instr);
   2465     }
   2466     case kMathExp: {
   2467       DCHECK(instr->representation().IsDouble());
   2468       DCHECK(instr->value()->representation().IsDouble());
   2469       LOperand* input = UseFixedDouble(instr->value(), d0);
   2470       LMathExp* result = new (zone()) LMathExp(input);
   2471       return MarkAsCall(DefineFixedDouble(result, d0), instr);
   2472     }
   2473     case kMathFloor: {
   2474       DCHECK(instr->value()->representation().IsDouble());
   2475       LOperand* input = UseRegisterAtStart(instr->value());
   2476       if (instr->representation().IsInteger32()) {
   2477         LMathFloorI* result = new(zone()) LMathFloorI(input);
   2478         return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
   2479       } else {
   2480         DCHECK(instr->representation().IsDouble());
   2481         LMathFloorD* result = new(zone()) LMathFloorD(input);
   2482         return DefineAsRegister(result);
   2483       }
   2484     }
   2485     case kMathLog: {
   2486       DCHECK(instr->representation().IsDouble());
   2487       DCHECK(instr->value()->representation().IsDouble());
   2488       LOperand* input = UseFixedDouble(instr->value(), d0);
   2489       LMathLog* result = new(zone()) LMathLog(input);
   2490       return MarkAsCall(DefineFixedDouble(result, d0), instr);
   2491     }
   2492     case kMathPowHalf: {
   2493       DCHECK(instr->representation().IsDouble());
   2494       DCHECK(instr->value()->representation().IsDouble());
   2495       LOperand* input = UseRegister(instr->value());
   2496       return DefineAsRegister(new(zone()) LMathPowHalf(input));
   2497     }
   2498     case kMathRound: {
   2499       DCHECK(instr->value()->representation().IsDouble());
   2500       LOperand* input = UseRegister(instr->value());
   2501       if (instr->representation().IsInteger32()) {
   2502         LOperand* temp = TempDoubleRegister();
   2503         LMathRoundI* result = new(zone()) LMathRoundI(input, temp);
   2504         return AssignEnvironment(DefineAsRegister(result));
   2505       } else {
   2506         DCHECK(instr->representation().IsDouble());
   2507         LMathRoundD* result = new(zone()) LMathRoundD(input);
   2508         return DefineAsRegister(result);
   2509       }
   2510     }
   2511     case kMathFround: {
   2512       DCHECK(instr->value()->representation().IsDouble());
   2513       LOperand* input = UseRegister(instr->value());
   2514       LMathFround* result = new (zone()) LMathFround(input);
   2515       return DefineAsRegister(result);
   2516     }
   2517     case kMathSqrt: {
   2518       DCHECK(instr->representation().IsDouble());
   2519       DCHECK(instr->value()->representation().IsDouble());
   2520       LOperand* input = UseRegisterAtStart(instr->value());
   2521       return DefineAsRegister(new(zone()) LMathSqrt(input));
   2522     }
   2523     case kMathClz32: {
   2524       DCHECK(instr->representation().IsInteger32());
   2525       DCHECK(instr->value()->representation().IsInteger32());
   2526       LOperand* input = UseRegisterAtStart(instr->value());
   2527       return DefineAsRegister(new(zone()) LMathClz32(input));
   2528     }
   2529     default:
   2530       UNREACHABLE();
   2531       return NULL;
   2532   }
   2533 }
   2534 
   2535 
   2536 LInstruction* LChunkBuilder::DoUnknownOSRValue(HUnknownOSRValue* instr) {
   2537   // Use an index that corresponds to the location in the unoptimized frame,
   2538   // which the optimized frame will subsume.
   2539   int env_index = instr->index();
   2540   int spill_index = 0;
   2541   if (instr->environment()->is_parameter_index(env_index)) {
   2542     spill_index = chunk_->GetParameterStackSlot(env_index);
   2543   } else {
   2544     spill_index = env_index - instr->environment()->first_local_index();
   2545     if (spill_index > LUnallocated::kMaxFixedSlotIndex) {
   2546       Retry(kTooManySpillSlotsNeededForOSR);
   2547       spill_index = 0;
   2548     }
   2549     spill_index += StandardFrameConstants::kFixedSlotCount;
   2550   }
   2551   return DefineAsSpilled(new(zone()) LUnknownOSRValue, spill_index);
   2552 }
   2553 
   2554 
   2555 LInstruction* LChunkBuilder::DoUseConst(HUseConst* instr) {
   2556   return NULL;
   2557 }
   2558 
   2559 
   2560 LInstruction* LChunkBuilder::DoForInPrepareMap(HForInPrepareMap* instr) {
   2561   LOperand* context = UseFixed(instr->context(), cp);
   2562   // Assign object to a fixed register different from those already used in
   2563   // LForInPrepareMap.
   2564   LOperand* object = UseFixed(instr->enumerable(), x0);
   2565   LForInPrepareMap* result = new(zone()) LForInPrepareMap(context, object);
   2566   return MarkAsCall(DefineFixed(result, x0), instr, CAN_DEOPTIMIZE_EAGERLY);
   2567 }
   2568 
   2569 
   2570 LInstruction* LChunkBuilder::DoForInCacheArray(HForInCacheArray* instr) {
   2571   LOperand* map = UseRegister(instr->map());
   2572   return AssignEnvironment(DefineAsRegister(new(zone()) LForInCacheArray(map)));
   2573 }
   2574 
   2575 
   2576 LInstruction* LChunkBuilder::DoCheckMapValue(HCheckMapValue* instr) {
   2577   LOperand* value = UseRegisterAtStart(instr->value());
   2578   LOperand* map = UseRegister(instr->map());
   2579   LOperand* temp = TempRegister();
   2580   return AssignEnvironment(new(zone()) LCheckMapValue(value, map, temp));
   2581 }
   2582 
   2583 
   2584 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   2585   LOperand* object = UseRegisterAtStart(instr->object());
   2586   LOperand* index = UseRegisterAndClobber(instr->index());
   2587   LLoadFieldByIndex* load = new(zone()) LLoadFieldByIndex(object, index);
   2588   LInstruction* result = DefineSameAsFirst(load);
   2589   return AssignPointerMap(result);
   2590 }
   2591 
   2592 
   2593 LInstruction* LChunkBuilder::DoWrapReceiver(HWrapReceiver* instr) {
   2594   LOperand* receiver = UseRegister(instr->receiver());
   2595   LOperand* function = UseRegister(instr->function());
   2596   LWrapReceiver* result = new(zone()) LWrapReceiver(receiver, function);
   2597   return AssignEnvironment(DefineAsRegister(result));
   2598 }
   2599 
   2600 }  // namespace internal
   2601 }  // namespace v8
   2602