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      1 // Copyright 2012 the V8 project authors. All rights reserved.7
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 #include "src/v8.h"
     29 
     30 #include "src/base/bits.h"
     31 #include "src/code-factory.h"
     32 #include "src/code-stubs.h"
     33 #include "src/hydrogen-osr.h"
     34 #include "src/ic/ic.h"
     35 #include "src/ic/stub-cache.h"
     36 #include "src/mips/lithium-codegen-mips.h"
     37 #include "src/mips/lithium-gap-resolver-mips.h"
     38 
     39 
     40 namespace v8 {
     41 namespace internal {
     42 
     43 
     44 class SafepointGenerator FINAL  : public CallWrapper {
     45  public:
     46   SafepointGenerator(LCodeGen* codegen,
     47                      LPointerMap* pointers,
     48                      Safepoint::DeoptMode mode)
     49       : codegen_(codegen),
     50         pointers_(pointers),
     51         deopt_mode_(mode) { }
     52   virtual ~SafepointGenerator() {}
     53 
     54   virtual void BeforeCall(int call_size) const OVERRIDE {}
     55 
     56   virtual void AfterCall() const OVERRIDE {
     57     codegen_->RecordSafepoint(pointers_, deopt_mode_);
     58   }
     59 
     60  private:
     61   LCodeGen* codegen_;
     62   LPointerMap* pointers_;
     63   Safepoint::DeoptMode deopt_mode_;
     64 };
     65 
     66 
     67 #define __ masm()->
     68 
     69 bool LCodeGen::GenerateCode() {
     70   LPhase phase("Z_Code generation", chunk());
     71   DCHECK(is_unused());
     72   status_ = GENERATING;
     73 
     74   // Open a frame scope to indicate that there is a frame on the stack.  The
     75   // NONE indicates that the scope shouldn't actually generate code to set up
     76   // the frame (that is done in GeneratePrologue).
     77   FrameScope frame_scope(masm_, StackFrame::NONE);
     78 
     79   return GeneratePrologue() && GenerateBody() && GenerateDeferredCode() &&
     80          GenerateJumpTable() && GenerateSafepointTable();
     81 }
     82 
     83 
     84 void LCodeGen::FinishCode(Handle<Code> code) {
     85   DCHECK(is_done());
     86   code->set_stack_slots(GetStackSlotCount());
     87   code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
     88   if (code->is_optimized_code()) RegisterWeakObjectsInOptimizedCode(code);
     89   PopulateDeoptimizationData(code);
     90 }
     91 
     92 
     93 void LCodeGen::SaveCallerDoubles() {
     94   DCHECK(info()->saves_caller_doubles());
     95   DCHECK(NeedsEagerFrame());
     96   Comment(";;; Save clobbered callee double registers");
     97   int count = 0;
     98   BitVector* doubles = chunk()->allocated_double_registers();
     99   BitVector::Iterator save_iterator(doubles);
    100   while (!save_iterator.Done()) {
    101     __ sdc1(DoubleRegister::FromAllocationIndex(save_iterator.Current()),
    102             MemOperand(sp, count * kDoubleSize));
    103     save_iterator.Advance();
    104     count++;
    105   }
    106 }
    107 
    108 
    109 void LCodeGen::RestoreCallerDoubles() {
    110   DCHECK(info()->saves_caller_doubles());
    111   DCHECK(NeedsEagerFrame());
    112   Comment(";;; Restore clobbered callee double registers");
    113   BitVector* doubles = chunk()->allocated_double_registers();
    114   BitVector::Iterator save_iterator(doubles);
    115   int count = 0;
    116   while (!save_iterator.Done()) {
    117     __ ldc1(DoubleRegister::FromAllocationIndex(save_iterator.Current()),
    118             MemOperand(sp, count * kDoubleSize));
    119     save_iterator.Advance();
    120     count++;
    121   }
    122 }
    123 
    124 
    125 bool LCodeGen::GeneratePrologue() {
    126   DCHECK(is_generating());
    127 
    128   if (info()->IsOptimizing()) {
    129     ProfileEntryHookStub::MaybeCallEntryHook(masm_);
    130 
    131 #ifdef DEBUG
    132     if (strlen(FLAG_stop_at) > 0 &&
    133         info_->function()->name()->IsUtf8EqualTo(CStrVector(FLAG_stop_at))) {
    134       __ stop("stop_at");
    135     }
    136 #endif
    137 
    138     // a1: Callee's JS function.
    139     // cp: Callee's context.
    140     // fp: Caller's frame pointer.
    141     // lr: Caller's pc.
    142 
    143     // Sloppy mode functions and builtins need to replace the receiver with the
    144     // global proxy when called as functions (without an explicit receiver
    145     // object).
    146     if (info_->this_has_uses() &&
    147         info_->strict_mode() == SLOPPY &&
    148         !info_->is_native()) {
    149       Label ok;
    150       int receiver_offset = info_->scope()->num_parameters() * kPointerSize;
    151       __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
    152       __ lw(a2, MemOperand(sp, receiver_offset));
    153       __ Branch(&ok, ne, a2, Operand(at));
    154 
    155       __ lw(a2, GlobalObjectOperand());
    156       __ lw(a2, FieldMemOperand(a2, GlobalObject::kGlobalProxyOffset));
    157 
    158       __ sw(a2, MemOperand(sp, receiver_offset));
    159 
    160       __ bind(&ok);
    161     }
    162   }
    163 
    164   info()->set_prologue_offset(masm_->pc_offset());
    165   if (NeedsEagerFrame()) {
    166     if (info()->IsStub()) {
    167       __ StubPrologue();
    168     } else {
    169       __ Prologue(info()->IsCodePreAgingActive());
    170     }
    171     frame_is_built_ = true;
    172     info_->AddNoFrameRange(0, masm_->pc_offset());
    173   }
    174 
    175   // Reserve space for the stack slots needed by the code.
    176   int slots = GetStackSlotCount();
    177   if (slots > 0) {
    178     if (FLAG_debug_code) {
    179       __ Subu(sp,  sp, Operand(slots * kPointerSize));
    180       __ Push(a0, a1);
    181       __ Addu(a0, sp, Operand(slots *  kPointerSize));
    182       __ li(a1, Operand(kSlotsZapValue));
    183       Label loop;
    184       __ bind(&loop);
    185       __ Subu(a0, a0, Operand(kPointerSize));
    186       __ sw(a1, MemOperand(a0, 2 * kPointerSize));
    187       __ Branch(&loop, ne, a0, Operand(sp));
    188       __ Pop(a0, a1);
    189     } else {
    190       __ Subu(sp, sp, Operand(slots * kPointerSize));
    191     }
    192   }
    193 
    194   if (info()->saves_caller_doubles()) {
    195     SaveCallerDoubles();
    196   }
    197 
    198   // Possibly allocate a local context.
    199   int heap_slots = info()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
    200   if (heap_slots > 0) {
    201     Comment(";;; Allocate local context");
    202     bool need_write_barrier = true;
    203     // Argument to NewContext is the function, which is in a1.
    204     if (heap_slots <= FastNewContextStub::kMaximumSlots) {
    205       FastNewContextStub stub(isolate(), heap_slots);
    206       __ CallStub(&stub);
    207       // Result of FastNewContextStub is always in new space.
    208       need_write_barrier = false;
    209     } else {
    210       __ push(a1);
    211       __ CallRuntime(Runtime::kNewFunctionContext, 1);
    212     }
    213     RecordSafepoint(Safepoint::kNoLazyDeopt);
    214     // Context is returned in both v0. It replaces the context passed to us.
    215     // It's saved in the stack and kept live in cp.
    216     __ mov(cp, v0);
    217     __ sw(v0, MemOperand(fp, StandardFrameConstants::kContextOffset));
    218     // Copy any necessary parameters into the context.
    219     int num_parameters = scope()->num_parameters();
    220     for (int i = 0; i < num_parameters; i++) {
    221       Variable* var = scope()->parameter(i);
    222       if (var->IsContextSlot()) {
    223         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
    224             (num_parameters - 1 - i) * kPointerSize;
    225         // Load parameter from stack.
    226         __ lw(a0, MemOperand(fp, parameter_offset));
    227         // Store it in the context.
    228         MemOperand target = ContextOperand(cp, var->index());
    229         __ sw(a0, target);
    230         // Update the write barrier. This clobbers a3 and a0.
    231         if (need_write_barrier) {
    232           __ RecordWriteContextSlot(
    233               cp, target.offset(), a0, a3, GetRAState(), kSaveFPRegs);
    234         } else if (FLAG_debug_code) {
    235           Label done;
    236           __ JumpIfInNewSpace(cp, a0, &done);
    237           __ Abort(kExpectedNewSpaceObject);
    238           __ bind(&done);
    239         }
    240       }
    241     }
    242     Comment(";;; End allocate local context");
    243   }
    244 
    245   // Trace the call.
    246   if (FLAG_trace && info()->IsOptimizing()) {
    247     // We have not executed any compiled code yet, so cp still holds the
    248     // incoming context.
    249     __ CallRuntime(Runtime::kTraceEnter, 0);
    250   }
    251   return !is_aborted();
    252 }
    253 
    254 
    255 void LCodeGen::GenerateOsrPrologue() {
    256   // Generate the OSR entry prologue at the first unknown OSR value, or if there
    257   // are none, at the OSR entrypoint instruction.
    258   if (osr_pc_offset_ >= 0) return;
    259 
    260   osr_pc_offset_ = masm()->pc_offset();
    261 
    262   // Adjust the frame size, subsuming the unoptimized frame into the
    263   // optimized frame.
    264   int slots = GetStackSlotCount() - graph()->osr()->UnoptimizedFrameSlots();
    265   DCHECK(slots >= 0);
    266   __ Subu(sp, sp, Operand(slots * kPointerSize));
    267 }
    268 
    269 
    270 void LCodeGen::GenerateBodyInstructionPre(LInstruction* instr) {
    271   if (instr->IsCall()) {
    272     EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
    273   }
    274   if (!instr->IsLazyBailout() && !instr->IsGap()) {
    275     safepoints_.BumpLastLazySafepointIndex();
    276   }
    277 }
    278 
    279 
    280 bool LCodeGen::GenerateDeferredCode() {
    281   DCHECK(is_generating());
    282   if (deferred_.length() > 0) {
    283     for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
    284       LDeferredCode* code = deferred_[i];
    285 
    286       HValue* value =
    287           instructions_->at(code->instruction_index())->hydrogen_value();
    288       RecordAndWritePosition(
    289           chunk()->graph()->SourcePositionToScriptPosition(value->position()));
    290 
    291       Comment(";;; <@%d,#%d> "
    292               "-------------------- Deferred %s --------------------",
    293               code->instruction_index(),
    294               code->instr()->hydrogen_value()->id(),
    295               code->instr()->Mnemonic());
    296       __ bind(code->entry());
    297       if (NeedsDeferredFrame()) {
    298         Comment(";;; Build frame");
    299         DCHECK(!frame_is_built_);
    300         DCHECK(info()->IsStub());
    301         frame_is_built_ = true;
    302         __ MultiPush(cp.bit() | fp.bit() | ra.bit());
    303         __ li(scratch0(), Operand(Smi::FromInt(StackFrame::STUB)));
    304         __ push(scratch0());
    305         __ Addu(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
    306         Comment(";;; Deferred code");
    307       }
    308       code->Generate();
    309       if (NeedsDeferredFrame()) {
    310         Comment(";;; Destroy frame");
    311         DCHECK(frame_is_built_);
    312         __ pop(at);
    313         __ MultiPop(cp.bit() | fp.bit() | ra.bit());
    314         frame_is_built_ = false;
    315       }
    316       __ jmp(code->exit());
    317     }
    318   }
    319   // Deferred code is the last part of the instruction sequence. Mark
    320   // the generated code as done unless we bailed out.
    321   if (!is_aborted()) status_ = DONE;
    322   return !is_aborted();
    323 }
    324 
    325 
    326 bool LCodeGen::GenerateJumpTable() {
    327   if (jump_table_.length() > 0) {
    328     Label needs_frame, call_deopt_entry;
    329 
    330     Comment(";;; -------------------- Jump table --------------------");
    331     Address base = jump_table_[0].address;
    332 
    333     Register entry_offset = t9;
    334 
    335     int length = jump_table_.length();
    336     for (int i = 0; i < length; i++) {
    337       Deoptimizer::JumpTableEntry* table_entry = &jump_table_[i];
    338       __ bind(&table_entry->label);
    339 
    340       DCHECK(table_entry->bailout_type == jump_table_[0].bailout_type);
    341       Address entry = table_entry->address;
    342       DeoptComment(table_entry->reason);
    343 
    344       // Second-level deopt table entries are contiguous and small, so instead
    345       // of loading the full, absolute address of each one, load an immediate
    346       // offset which will be added to the base address later.
    347       __ li(entry_offset, Operand(entry - base));
    348 
    349       if (table_entry->needs_frame) {
    350         DCHECK(!info()->saves_caller_doubles());
    351         if (needs_frame.is_bound()) {
    352           __ Branch(&needs_frame);
    353         } else {
    354           __ bind(&needs_frame);
    355           Comment(";;; call deopt with frame");
    356           __ MultiPush(cp.bit() | fp.bit() | ra.bit());
    357           // This variant of deopt can only be used with stubs. Since we don't
    358           // have a function pointer to install in the stack frame that we're
    359           // building, install a special marker there instead.
    360           DCHECK(info()->IsStub());
    361           __ li(at, Operand(Smi::FromInt(StackFrame::STUB)));
    362           __ push(at);
    363           __ Addu(fp, sp,
    364                   Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
    365           __ bind(&call_deopt_entry);
    366           // Add the base address to the offset previously loaded in
    367           // entry_offset.
    368           __ Addu(entry_offset, entry_offset,
    369                   Operand(ExternalReference::ForDeoptEntry(base)));
    370           __ Call(entry_offset);
    371         }
    372       } else {
    373         // The last entry can fall through into `call_deopt_entry`, avoiding a
    374         // branch.
    375         bool need_branch = ((i + 1) != length) || call_deopt_entry.is_bound();
    376 
    377         if (need_branch) __ Branch(&call_deopt_entry);
    378       }
    379     }
    380 
    381     if (!call_deopt_entry.is_bound()) {
    382       Comment(";;; call deopt");
    383       __ bind(&call_deopt_entry);
    384 
    385       if (info()->saves_caller_doubles()) {
    386         DCHECK(info()->IsStub());
    387         RestoreCallerDoubles();
    388       }
    389 
    390       // Add the base address to the offset previously loaded in entry_offset.
    391       __ Addu(entry_offset, entry_offset,
    392               Operand(ExternalReference::ForDeoptEntry(base)));
    393       __ Call(entry_offset);
    394     }
    395   }
    396   __ RecordComment("]");
    397 
    398   // The deoptimization jump table is the last part of the instruction
    399   // sequence. Mark the generated code as done unless we bailed out.
    400   if (!is_aborted()) status_ = DONE;
    401   return !is_aborted();
    402 }
    403 
    404 
    405 bool LCodeGen::GenerateSafepointTable() {
    406   DCHECK(is_done());
    407   safepoints_.Emit(masm(), GetStackSlotCount());
    408   return !is_aborted();
    409 }
    410 
    411 
    412 Register LCodeGen::ToRegister(int index) const {
    413   return Register::FromAllocationIndex(index);
    414 }
    415 
    416 
    417 DoubleRegister LCodeGen::ToDoubleRegister(int index) const {
    418   return DoubleRegister::FromAllocationIndex(index);
    419 }
    420 
    421 
    422 Register LCodeGen::ToRegister(LOperand* op) const {
    423   DCHECK(op->IsRegister());
    424   return ToRegister(op->index());
    425 }
    426 
    427 
    428 Register LCodeGen::EmitLoadRegister(LOperand* op, Register scratch) {
    429   if (op->IsRegister()) {
    430     return ToRegister(op->index());
    431   } else if (op->IsConstantOperand()) {
    432     LConstantOperand* const_op = LConstantOperand::cast(op);
    433     HConstant* constant = chunk_->LookupConstant(const_op);
    434     Handle<Object> literal = constant->handle(isolate());
    435     Representation r = chunk_->LookupLiteralRepresentation(const_op);
    436     if (r.IsInteger32()) {
    437       DCHECK(literal->IsNumber());
    438       __ li(scratch, Operand(static_cast<int32_t>(literal->Number())));
    439     } else if (r.IsSmi()) {
    440       DCHECK(constant->HasSmiValue());
    441       __ li(scratch, Operand(Smi::FromInt(constant->Integer32Value())));
    442     } else if (r.IsDouble()) {
    443       Abort(kEmitLoadRegisterUnsupportedDoubleImmediate);
    444     } else {
    445       DCHECK(r.IsSmiOrTagged());
    446       __ li(scratch, literal);
    447     }
    448     return scratch;
    449   } else if (op->IsStackSlot()) {
    450     __ lw(scratch, ToMemOperand(op));
    451     return scratch;
    452   }
    453   UNREACHABLE();
    454   return scratch;
    455 }
    456 
    457 
    458 DoubleRegister LCodeGen::ToDoubleRegister(LOperand* op) const {
    459   DCHECK(op->IsDoubleRegister());
    460   return ToDoubleRegister(op->index());
    461 }
    462 
    463 
    464 DoubleRegister LCodeGen::EmitLoadDoubleRegister(LOperand* op,
    465                                                 FloatRegister flt_scratch,
    466                                                 DoubleRegister dbl_scratch) {
    467   if (op->IsDoubleRegister()) {
    468     return ToDoubleRegister(op->index());
    469   } else if (op->IsConstantOperand()) {
    470     LConstantOperand* const_op = LConstantOperand::cast(op);
    471     HConstant* constant = chunk_->LookupConstant(const_op);
    472     Handle<Object> literal = constant->handle(isolate());
    473     Representation r = chunk_->LookupLiteralRepresentation(const_op);
    474     if (r.IsInteger32()) {
    475       DCHECK(literal->IsNumber());
    476       __ li(at, Operand(static_cast<int32_t>(literal->Number())));
    477       __ mtc1(at, flt_scratch);
    478       __ cvt_d_w(dbl_scratch, flt_scratch);
    479       return dbl_scratch;
    480     } else if (r.IsDouble()) {
    481       Abort(kUnsupportedDoubleImmediate);
    482     } else if (r.IsTagged()) {
    483       Abort(kUnsupportedTaggedImmediate);
    484     }
    485   } else if (op->IsStackSlot()) {
    486     MemOperand mem_op = ToMemOperand(op);
    487     __ ldc1(dbl_scratch, mem_op);
    488     return dbl_scratch;
    489   }
    490   UNREACHABLE();
    491   return dbl_scratch;
    492 }
    493 
    494 
    495 Handle<Object> LCodeGen::ToHandle(LConstantOperand* op) const {
    496   HConstant* constant = chunk_->LookupConstant(op);
    497   DCHECK(chunk_->LookupLiteralRepresentation(op).IsSmiOrTagged());
    498   return constant->handle(isolate());
    499 }
    500 
    501 
    502 bool LCodeGen::IsInteger32(LConstantOperand* op) const {
    503   return chunk_->LookupLiteralRepresentation(op).IsSmiOrInteger32();
    504 }
    505 
    506 
    507 bool LCodeGen::IsSmi(LConstantOperand* op) const {
    508   return chunk_->LookupLiteralRepresentation(op).IsSmi();
    509 }
    510 
    511 
    512 int32_t LCodeGen::ToInteger32(LConstantOperand* op) const {
    513   return ToRepresentation(op, Representation::Integer32());
    514 }
    515 
    516 
    517 int32_t LCodeGen::ToRepresentation(LConstantOperand* op,
    518                                    const Representation& r) const {
    519   HConstant* constant = chunk_->LookupConstant(op);
    520   int32_t value = constant->Integer32Value();
    521   if (r.IsInteger32()) return value;
    522   DCHECK(r.IsSmiOrTagged());
    523   return reinterpret_cast<int32_t>(Smi::FromInt(value));
    524 }
    525 
    526 
    527 Smi* LCodeGen::ToSmi(LConstantOperand* op) const {
    528   HConstant* constant = chunk_->LookupConstant(op);
    529   return Smi::FromInt(constant->Integer32Value());
    530 }
    531 
    532 
    533 double LCodeGen::ToDouble(LConstantOperand* op) const {
    534   HConstant* constant = chunk_->LookupConstant(op);
    535   DCHECK(constant->HasDoubleValue());
    536   return constant->DoubleValue();
    537 }
    538 
    539 
    540 Operand LCodeGen::ToOperand(LOperand* op) {
    541   if (op->IsConstantOperand()) {
    542     LConstantOperand* const_op = LConstantOperand::cast(op);
    543     HConstant* constant = chunk()->LookupConstant(const_op);
    544     Representation r = chunk_->LookupLiteralRepresentation(const_op);
    545     if (r.IsSmi()) {
    546       DCHECK(constant->HasSmiValue());
    547       return Operand(Smi::FromInt(constant->Integer32Value()));
    548     } else if (r.IsInteger32()) {
    549       DCHECK(constant->HasInteger32Value());
    550       return Operand(constant->Integer32Value());
    551     } else if (r.IsDouble()) {
    552       Abort(kToOperandUnsupportedDoubleImmediate);
    553     }
    554     DCHECK(r.IsTagged());
    555     return Operand(constant->handle(isolate()));
    556   } else if (op->IsRegister()) {
    557     return Operand(ToRegister(op));
    558   } else if (op->IsDoubleRegister()) {
    559     Abort(kToOperandIsDoubleRegisterUnimplemented);
    560     return Operand(0);
    561   }
    562   // Stack slots not implemented, use ToMemOperand instead.
    563   UNREACHABLE();
    564   return Operand(0);
    565 }
    566 
    567 
    568 static int ArgumentsOffsetWithoutFrame(int index) {
    569   DCHECK(index < 0);
    570   return -(index + 1) * kPointerSize;
    571 }
    572 
    573 
    574 MemOperand LCodeGen::ToMemOperand(LOperand* op) const {
    575   DCHECK(!op->IsRegister());
    576   DCHECK(!op->IsDoubleRegister());
    577   DCHECK(op->IsStackSlot() || op->IsDoubleStackSlot());
    578   if (NeedsEagerFrame()) {
    579     return MemOperand(fp, StackSlotOffset(op->index()));
    580   } else {
    581     // Retrieve parameter without eager stack-frame relative to the
    582     // stack-pointer.
    583     return MemOperand(sp, ArgumentsOffsetWithoutFrame(op->index()));
    584   }
    585 }
    586 
    587 
    588 MemOperand LCodeGen::ToHighMemOperand(LOperand* op) const {
    589   DCHECK(op->IsDoubleStackSlot());
    590   if (NeedsEagerFrame()) {
    591     return MemOperand(fp, StackSlotOffset(op->index()) + kPointerSize);
    592   } else {
    593     // Retrieve parameter without eager stack-frame relative to the
    594     // stack-pointer.
    595     return MemOperand(
    596         sp, ArgumentsOffsetWithoutFrame(op->index()) + kPointerSize);
    597   }
    598 }
    599 
    600 
    601 void LCodeGen::WriteTranslation(LEnvironment* environment,
    602                                 Translation* translation) {
    603   if (environment == NULL) return;
    604 
    605   // The translation includes one command per value in the environment.
    606   int translation_size = environment->translation_size();
    607   // The output frame height does not include the parameters.
    608   int height = translation_size - environment->parameter_count();
    609 
    610   WriteTranslation(environment->outer(), translation);
    611   bool has_closure_id = !info()->closure().is_null() &&
    612       !info()->closure().is_identical_to(environment->closure());
    613   int closure_id = has_closure_id
    614       ? DefineDeoptimizationLiteral(environment->closure())
    615       : Translation::kSelfLiteralId;
    616 
    617   switch (environment->frame_type()) {
    618     case JS_FUNCTION:
    619       translation->BeginJSFrame(environment->ast_id(), closure_id, height);
    620       break;
    621     case JS_CONSTRUCT:
    622       translation->BeginConstructStubFrame(closure_id, translation_size);
    623       break;
    624     case JS_GETTER:
    625       DCHECK(translation_size == 1);
    626       DCHECK(height == 0);
    627       translation->BeginGetterStubFrame(closure_id);
    628       break;
    629     case JS_SETTER:
    630       DCHECK(translation_size == 2);
    631       DCHECK(height == 0);
    632       translation->BeginSetterStubFrame(closure_id);
    633       break;
    634     case STUB:
    635       translation->BeginCompiledStubFrame();
    636       break;
    637     case ARGUMENTS_ADAPTOR:
    638       translation->BeginArgumentsAdaptorFrame(closure_id, translation_size);
    639       break;
    640   }
    641 
    642   int object_index = 0;
    643   int dematerialized_index = 0;
    644   for (int i = 0; i < translation_size; ++i) {
    645     LOperand* value = environment->values()->at(i);
    646     AddToTranslation(environment,
    647                      translation,
    648                      value,
    649                      environment->HasTaggedValueAt(i),
    650                      environment->HasUint32ValueAt(i),
    651                      &object_index,
    652                      &dematerialized_index);
    653   }
    654 }
    655 
    656 
    657 void LCodeGen::AddToTranslation(LEnvironment* environment,
    658                                 Translation* translation,
    659                                 LOperand* op,
    660                                 bool is_tagged,
    661                                 bool is_uint32,
    662                                 int* object_index_pointer,
    663                                 int* dematerialized_index_pointer) {
    664   if (op == LEnvironment::materialization_marker()) {
    665     int object_index = (*object_index_pointer)++;
    666     if (environment->ObjectIsDuplicateAt(object_index)) {
    667       int dupe_of = environment->ObjectDuplicateOfAt(object_index);
    668       translation->DuplicateObject(dupe_of);
    669       return;
    670     }
    671     int object_length = environment->ObjectLengthAt(object_index);
    672     if (environment->ObjectIsArgumentsAt(object_index)) {
    673       translation->BeginArgumentsObject(object_length);
    674     } else {
    675       translation->BeginCapturedObject(object_length);
    676     }
    677     int dematerialized_index = *dematerialized_index_pointer;
    678     int env_offset = environment->translation_size() + dematerialized_index;
    679     *dematerialized_index_pointer += object_length;
    680     for (int i = 0; i < object_length; ++i) {
    681       LOperand* value = environment->values()->at(env_offset + i);
    682       AddToTranslation(environment,
    683                        translation,
    684                        value,
    685                        environment->HasTaggedValueAt(env_offset + i),
    686                        environment->HasUint32ValueAt(env_offset + i),
    687                        object_index_pointer,
    688                        dematerialized_index_pointer);
    689     }
    690     return;
    691   }
    692 
    693   if (op->IsStackSlot()) {
    694     if (is_tagged) {
    695       translation->StoreStackSlot(op->index());
    696     } else if (is_uint32) {
    697       translation->StoreUint32StackSlot(op->index());
    698     } else {
    699       translation->StoreInt32StackSlot(op->index());
    700     }
    701   } else if (op->IsDoubleStackSlot()) {
    702     translation->StoreDoubleStackSlot(op->index());
    703   } else if (op->IsRegister()) {
    704     Register reg = ToRegister(op);
    705     if (is_tagged) {
    706       translation->StoreRegister(reg);
    707     } else if (is_uint32) {
    708       translation->StoreUint32Register(reg);
    709     } else {
    710       translation->StoreInt32Register(reg);
    711     }
    712   } else if (op->IsDoubleRegister()) {
    713     DoubleRegister reg = ToDoubleRegister(op);
    714     translation->StoreDoubleRegister(reg);
    715   } else if (op->IsConstantOperand()) {
    716     HConstant* constant = chunk()->LookupConstant(LConstantOperand::cast(op));
    717     int src_index = DefineDeoptimizationLiteral(constant->handle(isolate()));
    718     translation->StoreLiteral(src_index);
    719   } else {
    720     UNREACHABLE();
    721   }
    722 }
    723 
    724 
    725 void LCodeGen::CallCode(Handle<Code> code,
    726                         RelocInfo::Mode mode,
    727                         LInstruction* instr) {
    728   CallCodeGeneric(code, mode, instr, RECORD_SIMPLE_SAFEPOINT);
    729 }
    730 
    731 
    732 void LCodeGen::CallCodeGeneric(Handle<Code> code,
    733                                RelocInfo::Mode mode,
    734                                LInstruction* instr,
    735                                SafepointMode safepoint_mode) {
    736   DCHECK(instr != NULL);
    737   __ Call(code, mode);
    738   RecordSafepointWithLazyDeopt(instr, safepoint_mode);
    739 }
    740 
    741 
    742 void LCodeGen::CallRuntime(const Runtime::Function* function,
    743                            int num_arguments,
    744                            LInstruction* instr,
    745                            SaveFPRegsMode save_doubles) {
    746   DCHECK(instr != NULL);
    747 
    748   __ CallRuntime(function, num_arguments, save_doubles);
    749 
    750   RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
    751 }
    752 
    753 
    754 void LCodeGen::LoadContextFromDeferred(LOperand* context) {
    755   if (context->IsRegister()) {
    756     __ Move(cp, ToRegister(context));
    757   } else if (context->IsStackSlot()) {
    758     __ lw(cp, ToMemOperand(context));
    759   } else if (context->IsConstantOperand()) {
    760     HConstant* constant =
    761         chunk_->LookupConstant(LConstantOperand::cast(context));
    762     __ li(cp, Handle<Object>::cast(constant->handle(isolate())));
    763   } else {
    764     UNREACHABLE();
    765   }
    766 }
    767 
    768 
    769 void LCodeGen::CallRuntimeFromDeferred(Runtime::FunctionId id,
    770                                        int argc,
    771                                        LInstruction* instr,
    772                                        LOperand* context) {
    773   LoadContextFromDeferred(context);
    774   __ CallRuntimeSaveDoubles(id);
    775   RecordSafepointWithRegisters(
    776       instr->pointer_map(), argc, Safepoint::kNoLazyDeopt);
    777 }
    778 
    779 
    780 void LCodeGen::RegisterEnvironmentForDeoptimization(LEnvironment* environment,
    781                                                     Safepoint::DeoptMode mode) {
    782   environment->set_has_been_used();
    783   if (!environment->HasBeenRegistered()) {
    784     // Physical stack frame layout:
    785     // -x ............. -4  0 ..................................... y
    786     // [incoming arguments] [spill slots] [pushed outgoing arguments]
    787 
    788     // Layout of the environment:
    789     // 0 ..................................................... size-1
    790     // [parameters] [locals] [expression stack including arguments]
    791 
    792     // Layout of the translation:
    793     // 0 ........................................................ size - 1 + 4
    794     // [expression stack including arguments] [locals] [4 words] [parameters]
    795     // |>------------  translation_size ------------<|
    796 
    797     int frame_count = 0;
    798     int jsframe_count = 0;
    799     for (LEnvironment* e = environment; e != NULL; e = e->outer()) {
    800       ++frame_count;
    801       if (e->frame_type() == JS_FUNCTION) {
    802         ++jsframe_count;
    803       }
    804     }
    805     Translation translation(&translations_, frame_count, jsframe_count, zone());
    806     WriteTranslation(environment, &translation);
    807     int deoptimization_index = deoptimizations_.length();
    808     int pc_offset = masm()->pc_offset();
    809     environment->Register(deoptimization_index,
    810                           translation.index(),
    811                           (mode == Safepoint::kLazyDeopt) ? pc_offset : -1);
    812     deoptimizations_.Add(environment, zone());
    813   }
    814 }
    815 
    816 
    817 void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
    818                             Deoptimizer::BailoutType bailout_type,
    819                             Register src1, const Operand& src2,
    820                             const char* detail) {
    821   LEnvironment* environment = instr->environment();
    822   RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
    823   DCHECK(environment->HasBeenRegistered());
    824   int id = environment->deoptimization_index();
    825   DCHECK(info()->IsOptimizing() || info()->IsStub());
    826   Address entry =
    827       Deoptimizer::GetDeoptimizationEntry(isolate(), id, bailout_type);
    828   if (entry == NULL) {
    829     Abort(kBailoutWasNotPrepared);
    830     return;
    831   }
    832 
    833   if (FLAG_deopt_every_n_times != 0 && !info()->IsStub()) {
    834     Register scratch = scratch0();
    835     ExternalReference count = ExternalReference::stress_deopt_count(isolate());
    836     Label no_deopt;
    837     __ Push(a1, scratch);
    838     __ li(scratch, Operand(count));
    839     __ lw(a1, MemOperand(scratch));
    840     __ Subu(a1, a1, Operand(1));
    841     __ Branch(&no_deopt, ne, a1, Operand(zero_reg));
    842     __ li(a1, Operand(FLAG_deopt_every_n_times));
    843     __ sw(a1, MemOperand(scratch));
    844     __ Pop(a1, scratch);
    845 
    846     __ Call(entry, RelocInfo::RUNTIME_ENTRY);
    847     __ bind(&no_deopt);
    848     __ sw(a1, MemOperand(scratch));
    849     __ Pop(a1, scratch);
    850   }
    851 
    852   if (info()->ShouldTrapOnDeopt()) {
    853     Label skip;
    854     if (condition != al) {
    855       __ Branch(&skip, NegateCondition(condition), src1, src2);
    856     }
    857     __ stop("trap_on_deopt");
    858     __ bind(&skip);
    859   }
    860 
    861   Deoptimizer::Reason reason(instr->hydrogen_value()->position().raw(),
    862                              instr->Mnemonic(), detail);
    863   DCHECK(info()->IsStub() || frame_is_built_);
    864   // Go through jump table if we need to handle condition, build frame, or
    865   // restore caller doubles.
    866   if (condition == al && frame_is_built_ &&
    867       !info()->saves_caller_doubles()) {
    868     DeoptComment(reason);
    869     __ Call(entry, RelocInfo::RUNTIME_ENTRY, condition, src1, src2);
    870   } else {
    871     Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
    872                                             !frame_is_built_);
    873     // We often have several deopts to the same entry, reuse the last
    874     // jump entry if this is the case.
    875     if (jump_table_.is_empty() ||
    876         !table_entry.IsEquivalentTo(jump_table_.last())) {
    877       jump_table_.Add(table_entry, zone());
    878     }
    879     __ Branch(&jump_table_.last().label, condition, src1, src2);
    880   }
    881 }
    882 
    883 
    884 void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
    885                             Register src1, const Operand& src2,
    886                             const char* detail) {
    887   Deoptimizer::BailoutType bailout_type = info()->IsStub()
    888       ? Deoptimizer::LAZY
    889       : Deoptimizer::EAGER;
    890   DeoptimizeIf(condition, instr, bailout_type, src1, src2, detail);
    891 }
    892 
    893 
    894 void LCodeGen::PopulateDeoptimizationData(Handle<Code> code) {
    895   int length = deoptimizations_.length();
    896   if (length == 0) return;
    897   Handle<DeoptimizationInputData> data =
    898       DeoptimizationInputData::New(isolate(), length, TENURED);
    899 
    900   Handle<ByteArray> translations =
    901       translations_.CreateByteArray(isolate()->factory());
    902   data->SetTranslationByteArray(*translations);
    903   data->SetInlinedFunctionCount(Smi::FromInt(inlined_function_count_));
    904   data->SetOptimizationId(Smi::FromInt(info_->optimization_id()));
    905   if (info_->IsOptimizing()) {
    906     // Reference to shared function info does not change between phases.
    907     AllowDeferredHandleDereference allow_handle_dereference;
    908     data->SetSharedFunctionInfo(*info_->shared_info());
    909   } else {
    910     data->SetSharedFunctionInfo(Smi::FromInt(0));
    911   }
    912 
    913   Handle<FixedArray> literals =
    914       factory()->NewFixedArray(deoptimization_literals_.length(), TENURED);
    915   { AllowDeferredHandleDereference copy_handles;
    916     for (int i = 0; i < deoptimization_literals_.length(); i++) {
    917       literals->set(i, *deoptimization_literals_[i]);
    918     }
    919     data->SetLiteralArray(*literals);
    920   }
    921 
    922   data->SetOsrAstId(Smi::FromInt(info_->osr_ast_id().ToInt()));
    923   data->SetOsrPcOffset(Smi::FromInt(osr_pc_offset_));
    924 
    925   // Populate the deoptimization entries.
    926   for (int i = 0; i < length; i++) {
    927     LEnvironment* env = deoptimizations_[i];
    928     data->SetAstId(i, env->ast_id());
    929     data->SetTranslationIndex(i, Smi::FromInt(env->translation_index()));
    930     data->SetArgumentsStackHeight(i,
    931                                   Smi::FromInt(env->arguments_stack_height()));
    932     data->SetPc(i, Smi::FromInt(env->pc_offset()));
    933   }
    934   code->set_deoptimization_data(*data);
    935 }
    936 
    937 
    938 int LCodeGen::DefineDeoptimizationLiteral(Handle<Object> literal) {
    939   int result = deoptimization_literals_.length();
    940   for (int i = 0; i < deoptimization_literals_.length(); ++i) {
    941     if (deoptimization_literals_[i].is_identical_to(literal)) return i;
    942   }
    943   deoptimization_literals_.Add(literal, zone());
    944   return result;
    945 }
    946 
    947 
    948 void LCodeGen::PopulateDeoptimizationLiteralsWithInlinedFunctions() {
    949   DCHECK(deoptimization_literals_.length() == 0);
    950 
    951   const ZoneList<Handle<JSFunction> >* inlined_closures =
    952       chunk()->inlined_closures();
    953 
    954   for (int i = 0, length = inlined_closures->length();
    955        i < length;
    956        i++) {
    957     DefineDeoptimizationLiteral(inlined_closures->at(i));
    958   }
    959 
    960   inlined_function_count_ = deoptimization_literals_.length();
    961 }
    962 
    963 
    964 void LCodeGen::RecordSafepointWithLazyDeopt(
    965     LInstruction* instr, SafepointMode safepoint_mode) {
    966   if (safepoint_mode == RECORD_SIMPLE_SAFEPOINT) {
    967     RecordSafepoint(instr->pointer_map(), Safepoint::kLazyDeopt);
    968   } else {
    969     DCHECK(safepoint_mode == RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
    970     RecordSafepointWithRegisters(
    971         instr->pointer_map(), 0, Safepoint::kLazyDeopt);
    972   }
    973 }
    974 
    975 
    976 void LCodeGen::RecordSafepoint(
    977     LPointerMap* pointers,
    978     Safepoint::Kind kind,
    979     int arguments,
    980     Safepoint::DeoptMode deopt_mode) {
    981   DCHECK(expected_safepoint_kind_ == kind);
    982 
    983   const ZoneList<LOperand*>* operands = pointers->GetNormalizedOperands();
    984   Safepoint safepoint = safepoints_.DefineSafepoint(masm(),
    985       kind, arguments, deopt_mode);
    986   for (int i = 0; i < operands->length(); i++) {
    987     LOperand* pointer = operands->at(i);
    988     if (pointer->IsStackSlot()) {
    989       safepoint.DefinePointerSlot(pointer->index(), zone());
    990     } else if (pointer->IsRegister() && (kind & Safepoint::kWithRegisters)) {
    991       safepoint.DefinePointerRegister(ToRegister(pointer), zone());
    992     }
    993   }
    994 }
    995 
    996 
    997 void LCodeGen::RecordSafepoint(LPointerMap* pointers,
    998                                Safepoint::DeoptMode deopt_mode) {
    999   RecordSafepoint(pointers, Safepoint::kSimple, 0, deopt_mode);
   1000 }
   1001 
   1002 
   1003 void LCodeGen::RecordSafepoint(Safepoint::DeoptMode deopt_mode) {
   1004   LPointerMap empty_pointers(zone());
   1005   RecordSafepoint(&empty_pointers, deopt_mode);
   1006 }
   1007 
   1008 
   1009 void LCodeGen::RecordSafepointWithRegisters(LPointerMap* pointers,
   1010                                             int arguments,
   1011                                             Safepoint::DeoptMode deopt_mode) {
   1012   RecordSafepoint(
   1013       pointers, Safepoint::kWithRegisters, arguments, deopt_mode);
   1014 }
   1015 
   1016 
   1017 void LCodeGen::RecordAndWritePosition(int position) {
   1018   if (position == RelocInfo::kNoPosition) return;
   1019   masm()->positions_recorder()->RecordPosition(position);
   1020   masm()->positions_recorder()->WriteRecordedPositions();
   1021 }
   1022 
   1023 
   1024 static const char* LabelType(LLabel* label) {
   1025   if (label->is_loop_header()) return " (loop header)";
   1026   if (label->is_osr_entry()) return " (OSR entry)";
   1027   return "";
   1028 }
   1029 
   1030 
   1031 void LCodeGen::DoLabel(LLabel* label) {
   1032   Comment(";;; <@%d,#%d> -------------------- B%d%s --------------------",
   1033           current_instruction_,
   1034           label->hydrogen_value()->id(),
   1035           label->block_id(),
   1036           LabelType(label));
   1037   __ bind(label->label());
   1038   current_block_ = label->block_id();
   1039   DoGap(label);
   1040 }
   1041 
   1042 
   1043 void LCodeGen::DoParallelMove(LParallelMove* move) {
   1044   resolver_.Resolve(move);
   1045 }
   1046 
   1047 
   1048 void LCodeGen::DoGap(LGap* gap) {
   1049   for (int i = LGap::FIRST_INNER_POSITION;
   1050        i <= LGap::LAST_INNER_POSITION;
   1051        i++) {
   1052     LGap::InnerPosition inner_pos = static_cast<LGap::InnerPosition>(i);
   1053     LParallelMove* move = gap->GetParallelMove(inner_pos);
   1054     if (move != NULL) DoParallelMove(move);
   1055   }
   1056 }
   1057 
   1058 
   1059 void LCodeGen::DoInstructionGap(LInstructionGap* instr) {
   1060   DoGap(instr);
   1061 }
   1062 
   1063 
   1064 void LCodeGen::DoParameter(LParameter* instr) {
   1065   // Nothing to do.
   1066 }
   1067 
   1068 
   1069 void LCodeGen::DoCallStub(LCallStub* instr) {
   1070   DCHECK(ToRegister(instr->context()).is(cp));
   1071   DCHECK(ToRegister(instr->result()).is(v0));
   1072   switch (instr->hydrogen()->major_key()) {
   1073     case CodeStub::RegExpExec: {
   1074       RegExpExecStub stub(isolate());
   1075       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   1076       break;
   1077     }
   1078     case CodeStub::SubString: {
   1079       SubStringStub stub(isolate());
   1080       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   1081       break;
   1082     }
   1083     case CodeStub::StringCompare: {
   1084       StringCompareStub stub(isolate());
   1085       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   1086       break;
   1087     }
   1088     default:
   1089       UNREACHABLE();
   1090   }
   1091 }
   1092 
   1093 
   1094 void LCodeGen::DoUnknownOSRValue(LUnknownOSRValue* instr) {
   1095   GenerateOsrPrologue();
   1096 }
   1097 
   1098 
   1099 void LCodeGen::DoModByPowerOf2I(LModByPowerOf2I* instr) {
   1100   Register dividend = ToRegister(instr->dividend());
   1101   int32_t divisor = instr->divisor();
   1102   DCHECK(dividend.is(ToRegister(instr->result())));
   1103 
   1104   // Theoretically, a variation of the branch-free code for integer division by
   1105   // a power of 2 (calculating the remainder via an additional multiplication
   1106   // (which gets simplified to an 'and') and subtraction) should be faster, and
   1107   // this is exactly what GCC and clang emit. Nevertheless, benchmarks seem to
   1108   // indicate that positive dividends are heavily favored, so the branching
   1109   // version performs better.
   1110   HMod* hmod = instr->hydrogen();
   1111   int32_t mask = divisor < 0 ? -(divisor + 1) : (divisor - 1);
   1112   Label dividend_is_not_negative, done;
   1113 
   1114   if (hmod->CheckFlag(HValue::kLeftCanBeNegative)) {
   1115     __ Branch(&dividend_is_not_negative, ge, dividend, Operand(zero_reg));
   1116     // Note: The code below even works when right contains kMinInt.
   1117     __ subu(dividend, zero_reg, dividend);
   1118     __ And(dividend, dividend, Operand(mask));
   1119     if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1120       DeoptimizeIf(eq, instr, dividend, Operand(zero_reg));
   1121     }
   1122     __ Branch(USE_DELAY_SLOT, &done);
   1123     __ subu(dividend, zero_reg, dividend);
   1124   }
   1125 
   1126   __ bind(&dividend_is_not_negative);
   1127   __ And(dividend, dividend, Operand(mask));
   1128   __ bind(&done);
   1129 }
   1130 
   1131 
   1132 void LCodeGen::DoModByConstI(LModByConstI* instr) {
   1133   Register dividend = ToRegister(instr->dividend());
   1134   int32_t divisor = instr->divisor();
   1135   Register result = ToRegister(instr->result());
   1136   DCHECK(!dividend.is(result));
   1137 
   1138   if (divisor == 0) {
   1139     DeoptimizeIf(al, instr);
   1140     return;
   1141   }
   1142 
   1143   __ TruncatingDiv(result, dividend, Abs(divisor));
   1144   __ Mul(result, result, Operand(Abs(divisor)));
   1145   __ Subu(result, dividend, Operand(result));
   1146 
   1147   // Check for negative zero.
   1148   HMod* hmod = instr->hydrogen();
   1149   if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1150     Label remainder_not_zero;
   1151     __ Branch(&remainder_not_zero, ne, result, Operand(zero_reg));
   1152     DeoptimizeIf(lt, instr, dividend, Operand(zero_reg));
   1153     __ bind(&remainder_not_zero);
   1154   }
   1155 }
   1156 
   1157 
   1158 void LCodeGen::DoModI(LModI* instr) {
   1159   HMod* hmod = instr->hydrogen();
   1160   const Register left_reg = ToRegister(instr->left());
   1161   const Register right_reg = ToRegister(instr->right());
   1162   const Register result_reg = ToRegister(instr->result());
   1163 
   1164   // div runs in the background while we check for special cases.
   1165   __ Mod(result_reg, left_reg, right_reg);
   1166 
   1167   Label done;
   1168   // Check for x % 0, we have to deopt in this case because we can't return a
   1169   // NaN.
   1170   if (hmod->CheckFlag(HValue::kCanBeDivByZero)) {
   1171     DeoptimizeIf(eq, instr, right_reg, Operand(zero_reg));
   1172   }
   1173 
   1174   // Check for kMinInt % -1, div will return kMinInt, which is not what we
   1175   // want. We have to deopt if we care about -0, because we can't return that.
   1176   if (hmod->CheckFlag(HValue::kCanOverflow)) {
   1177     Label no_overflow_possible;
   1178     __ Branch(&no_overflow_possible, ne, left_reg, Operand(kMinInt));
   1179     if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1180       DeoptimizeIf(eq, instr, right_reg, Operand(-1));
   1181     } else {
   1182       __ Branch(&no_overflow_possible, ne, right_reg, Operand(-1));
   1183       __ Branch(USE_DELAY_SLOT, &done);
   1184       __ mov(result_reg, zero_reg);
   1185     }
   1186     __ bind(&no_overflow_possible);
   1187   }
   1188 
   1189   // If we care about -0, test if the dividend is <0 and the result is 0.
   1190   __ Branch(&done, ge, left_reg, Operand(zero_reg));
   1191   if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1192     DeoptimizeIf(eq, instr, result_reg, Operand(zero_reg));
   1193   }
   1194   __ bind(&done);
   1195 }
   1196 
   1197 
   1198 void LCodeGen::DoDivByPowerOf2I(LDivByPowerOf2I* instr) {
   1199   Register dividend = ToRegister(instr->dividend());
   1200   int32_t divisor = instr->divisor();
   1201   Register result = ToRegister(instr->result());
   1202   DCHECK(divisor == kMinInt || base::bits::IsPowerOfTwo32(Abs(divisor)));
   1203   DCHECK(!result.is(dividend));
   1204 
   1205   // Check for (0 / -x) that will produce negative zero.
   1206   HDiv* hdiv = instr->hydrogen();
   1207   if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
   1208     DeoptimizeIf(eq, instr, dividend, Operand(zero_reg));
   1209   }
   1210   // Check for (kMinInt / -1).
   1211   if (hdiv->CheckFlag(HValue::kCanOverflow) && divisor == -1) {
   1212     DeoptimizeIf(eq, instr, dividend, Operand(kMinInt));
   1213   }
   1214   // Deoptimize if remainder will not be 0.
   1215   if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32) &&
   1216       divisor != 1 && divisor != -1) {
   1217     int32_t mask = divisor < 0 ? -(divisor + 1) : (divisor - 1);
   1218     __ And(at, dividend, Operand(mask));
   1219     DeoptimizeIf(ne, instr, at, Operand(zero_reg));
   1220   }
   1221 
   1222   if (divisor == -1) {  // Nice shortcut, not needed for correctness.
   1223     __ Subu(result, zero_reg, dividend);
   1224     return;
   1225   }
   1226   uint16_t shift = WhichPowerOf2Abs(divisor);
   1227   if (shift == 0) {
   1228     __ Move(result, dividend);
   1229   } else if (shift == 1) {
   1230     __ srl(result, dividend, 31);
   1231     __ Addu(result, dividend, Operand(result));
   1232   } else {
   1233     __ sra(result, dividend, 31);
   1234     __ srl(result, result, 32 - shift);
   1235     __ Addu(result, dividend, Operand(result));
   1236   }
   1237   if (shift > 0) __ sra(result, result, shift);
   1238   if (divisor < 0) __ Subu(result, zero_reg, result);
   1239 }
   1240 
   1241 
   1242 void LCodeGen::DoDivByConstI(LDivByConstI* instr) {
   1243   Register dividend = ToRegister(instr->dividend());
   1244   int32_t divisor = instr->divisor();
   1245   Register result = ToRegister(instr->result());
   1246   DCHECK(!dividend.is(result));
   1247 
   1248   if (divisor == 0) {
   1249     DeoptimizeIf(al, instr);
   1250     return;
   1251   }
   1252 
   1253   // Check for (0 / -x) that will produce negative zero.
   1254   HDiv* hdiv = instr->hydrogen();
   1255   if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
   1256     DeoptimizeIf(eq, instr, dividend, Operand(zero_reg));
   1257   }
   1258 
   1259   __ TruncatingDiv(result, dividend, Abs(divisor));
   1260   if (divisor < 0) __ Subu(result, zero_reg, result);
   1261 
   1262   if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
   1263     __ Mul(scratch0(), result, Operand(divisor));
   1264     __ Subu(scratch0(), scratch0(), dividend);
   1265     DeoptimizeIf(ne, instr, scratch0(), Operand(zero_reg));
   1266   }
   1267 }
   1268 
   1269 
   1270 // TODO(svenpanne) Refactor this to avoid code duplication with DoFlooringDivI.
   1271 void LCodeGen::DoDivI(LDivI* instr) {
   1272   HBinaryOperation* hdiv = instr->hydrogen();
   1273   Register dividend = ToRegister(instr->dividend());
   1274   Register divisor = ToRegister(instr->divisor());
   1275   const Register result = ToRegister(instr->result());
   1276   Register remainder = ToRegister(instr->temp());
   1277 
   1278   // On MIPS div is asynchronous - it will run in the background while we
   1279   // check for special cases.
   1280   __ Div(remainder, result, dividend, divisor);
   1281 
   1282   // Check for x / 0.
   1283   if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
   1284     DeoptimizeIf(eq, instr, divisor, Operand(zero_reg));
   1285   }
   1286 
   1287   // Check for (0 / -x) that will produce negative zero.
   1288   if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1289     Label left_not_zero;
   1290     __ Branch(&left_not_zero, ne, dividend, Operand(zero_reg));
   1291     DeoptimizeIf(lt, instr, divisor, Operand(zero_reg));
   1292     __ bind(&left_not_zero);
   1293   }
   1294 
   1295   // Check for (kMinInt / -1).
   1296   if (hdiv->CheckFlag(HValue::kCanOverflow) &&
   1297       !hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
   1298     Label left_not_min_int;
   1299     __ Branch(&left_not_min_int, ne, dividend, Operand(kMinInt));
   1300     DeoptimizeIf(eq, instr, divisor, Operand(-1));
   1301     __ bind(&left_not_min_int);
   1302   }
   1303 
   1304   if (!hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
   1305     DeoptimizeIf(ne, instr, remainder, Operand(zero_reg));
   1306   }
   1307 }
   1308 
   1309 
   1310 void LCodeGen::DoMultiplyAddD(LMultiplyAddD* instr) {
   1311   DoubleRegister addend = ToDoubleRegister(instr->addend());
   1312   DoubleRegister multiplier = ToDoubleRegister(instr->multiplier());
   1313   DoubleRegister multiplicand = ToDoubleRegister(instr->multiplicand());
   1314 
   1315   // This is computed in-place.
   1316   DCHECK(addend.is(ToDoubleRegister(instr->result())));
   1317 
   1318   __ madd_d(addend, addend, multiplier, multiplicand);
   1319 }
   1320 
   1321 
   1322 void LCodeGen::DoFlooringDivByPowerOf2I(LFlooringDivByPowerOf2I* instr) {
   1323   Register dividend = ToRegister(instr->dividend());
   1324   Register result = ToRegister(instr->result());
   1325   int32_t divisor = instr->divisor();
   1326   Register scratch = result.is(dividend) ? scratch0() : dividend;
   1327   DCHECK(!result.is(dividend) || !scratch.is(dividend));
   1328 
   1329   // If the divisor is 1, return the dividend.
   1330   if (divisor == 1) {
   1331     __ Move(result, dividend);
   1332     return;
   1333   }
   1334 
   1335   // If the divisor is positive, things are easy: There can be no deopts and we
   1336   // can simply do an arithmetic right shift.
   1337   uint16_t shift = WhichPowerOf2Abs(divisor);
   1338   if (divisor > 1) {
   1339     __ sra(result, dividend, shift);
   1340     return;
   1341   }
   1342 
   1343   // If the divisor is negative, we have to negate and handle edge cases.
   1344 
   1345   // dividend can be the same register as result so save the value of it
   1346   // for checking overflow.
   1347   __ Move(scratch, dividend);
   1348 
   1349   __ Subu(result, zero_reg, dividend);
   1350   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1351     DeoptimizeIf(eq, instr, result, Operand(zero_reg));
   1352   }
   1353 
   1354   // Dividing by -1 is basically negation, unless we overflow.
   1355   __ Xor(scratch, scratch, result);
   1356   if (divisor == -1) {
   1357     if (instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
   1358       DeoptimizeIf(ge, instr, scratch, Operand(zero_reg));
   1359     }
   1360     return;
   1361   }
   1362 
   1363   // If the negation could not overflow, simply shifting is OK.
   1364   if (!instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
   1365     __ sra(result, result, shift);
   1366     return;
   1367   }
   1368 
   1369   Label no_overflow, done;
   1370   __ Branch(&no_overflow, lt, scratch, Operand(zero_reg));
   1371   __ li(result, Operand(kMinInt / divisor));
   1372   __ Branch(&done);
   1373   __ bind(&no_overflow);
   1374   __ sra(result, result, shift);
   1375   __ bind(&done);
   1376 }
   1377 
   1378 
   1379 void LCodeGen::DoFlooringDivByConstI(LFlooringDivByConstI* instr) {
   1380   Register dividend = ToRegister(instr->dividend());
   1381   int32_t divisor = instr->divisor();
   1382   Register result = ToRegister(instr->result());
   1383   DCHECK(!dividend.is(result));
   1384 
   1385   if (divisor == 0) {
   1386     DeoptimizeIf(al, instr);
   1387     return;
   1388   }
   1389 
   1390   // Check for (0 / -x) that will produce negative zero.
   1391   HMathFloorOfDiv* hdiv = instr->hydrogen();
   1392   if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
   1393     DeoptimizeIf(eq, instr, dividend, Operand(zero_reg));
   1394   }
   1395 
   1396   // Easy case: We need no dynamic check for the dividend and the flooring
   1397   // division is the same as the truncating division.
   1398   if ((divisor > 0 && !hdiv->CheckFlag(HValue::kLeftCanBeNegative)) ||
   1399       (divisor < 0 && !hdiv->CheckFlag(HValue::kLeftCanBePositive))) {
   1400     __ TruncatingDiv(result, dividend, Abs(divisor));
   1401     if (divisor < 0) __ Subu(result, zero_reg, result);
   1402     return;
   1403   }
   1404 
   1405   // In the general case we may need to adjust before and after the truncating
   1406   // division to get a flooring division.
   1407   Register temp = ToRegister(instr->temp());
   1408   DCHECK(!temp.is(dividend) && !temp.is(result));
   1409   Label needs_adjustment, done;
   1410   __ Branch(&needs_adjustment, divisor > 0 ? lt : gt,
   1411             dividend, Operand(zero_reg));
   1412   __ TruncatingDiv(result, dividend, Abs(divisor));
   1413   if (divisor < 0) __ Subu(result, zero_reg, result);
   1414   __ jmp(&done);
   1415   __ bind(&needs_adjustment);
   1416   __ Addu(temp, dividend, Operand(divisor > 0 ? 1 : -1));
   1417   __ TruncatingDiv(result, temp, Abs(divisor));
   1418   if (divisor < 0) __ Subu(result, zero_reg, result);
   1419   __ Subu(result, result, Operand(1));
   1420   __ bind(&done);
   1421 }
   1422 
   1423 
   1424 // TODO(svenpanne) Refactor this to avoid code duplication with DoDivI.
   1425 void LCodeGen::DoFlooringDivI(LFlooringDivI* instr) {
   1426   HBinaryOperation* hdiv = instr->hydrogen();
   1427   Register dividend = ToRegister(instr->dividend());
   1428   Register divisor = ToRegister(instr->divisor());
   1429   const Register result = ToRegister(instr->result());
   1430   Register remainder = scratch0();
   1431   // On MIPS div is asynchronous - it will run in the background while we
   1432   // check for special cases.
   1433   __ Div(remainder, result, dividend, divisor);
   1434 
   1435   // Check for x / 0.
   1436   if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
   1437     DeoptimizeIf(eq, instr, divisor, Operand(zero_reg));
   1438   }
   1439 
   1440   // Check for (0 / -x) that will produce negative zero.
   1441   if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
   1442     Label left_not_zero;
   1443     __ Branch(&left_not_zero, ne, dividend, Operand(zero_reg));
   1444     DeoptimizeIf(lt, instr, divisor, Operand(zero_reg));
   1445     __ bind(&left_not_zero);
   1446   }
   1447 
   1448   // Check for (kMinInt / -1).
   1449   if (hdiv->CheckFlag(HValue::kCanOverflow) &&
   1450       !hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
   1451     Label left_not_min_int;
   1452     __ Branch(&left_not_min_int, ne, dividend, Operand(kMinInt));
   1453     DeoptimizeIf(eq, instr, divisor, Operand(-1));
   1454     __ bind(&left_not_min_int);
   1455   }
   1456 
   1457   // We performed a truncating division. Correct the result if necessary.
   1458   Label done;
   1459   __ Branch(&done, eq, remainder, Operand(zero_reg), USE_DELAY_SLOT);
   1460   __ Xor(remainder, remainder, Operand(divisor));
   1461   __ Branch(&done, ge, remainder, Operand(zero_reg));
   1462   __ Subu(result, result, Operand(1));
   1463   __ bind(&done);
   1464 }
   1465 
   1466 
   1467 void LCodeGen::DoMulI(LMulI* instr) {
   1468   Register scratch = scratch0();
   1469   Register result = ToRegister(instr->result());
   1470   // Note that result may alias left.
   1471   Register left = ToRegister(instr->left());
   1472   LOperand* right_op = instr->right();
   1473 
   1474   bool bailout_on_minus_zero =
   1475     instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);
   1476   bool overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
   1477 
   1478   if (right_op->IsConstantOperand()) {
   1479     int32_t constant = ToInteger32(LConstantOperand::cast(right_op));
   1480 
   1481     if (bailout_on_minus_zero && (constant < 0)) {
   1482       // The case of a null constant will be handled separately.
   1483       // If constant is negative and left is null, the result should be -0.
   1484       DeoptimizeIf(eq, instr, left, Operand(zero_reg));
   1485     }
   1486 
   1487     switch (constant) {
   1488       case -1:
   1489         if (overflow) {
   1490           __ SubuAndCheckForOverflow(result, zero_reg, left, scratch);
   1491           DeoptimizeIf(lt, instr, scratch, Operand(zero_reg));
   1492         } else {
   1493           __ Subu(result, zero_reg, left);
   1494         }
   1495         break;
   1496       case 0:
   1497         if (bailout_on_minus_zero) {
   1498           // If left is strictly negative and the constant is null, the
   1499           // result is -0. Deoptimize if required, otherwise return 0.
   1500           DeoptimizeIf(lt, instr, left, Operand(zero_reg));
   1501         }
   1502         __ mov(result, zero_reg);
   1503         break;
   1504       case 1:
   1505         // Nothing to do.
   1506         __ Move(result, left);
   1507         break;
   1508       default:
   1509         // Multiplying by powers of two and powers of two plus or minus
   1510         // one can be done faster with shifted operands.
   1511         // For other constants we emit standard code.
   1512         int32_t mask = constant >> 31;
   1513         uint32_t constant_abs = (constant + mask) ^ mask;
   1514 
   1515         if (base::bits::IsPowerOfTwo32(constant_abs)) {
   1516           int32_t shift = WhichPowerOf2(constant_abs);
   1517           __ sll(result, left, shift);
   1518           // Correct the sign of the result if the constant is negative.
   1519           if (constant < 0)  __ Subu(result, zero_reg, result);
   1520         } else if (base::bits::IsPowerOfTwo32(constant_abs - 1)) {
   1521           int32_t shift = WhichPowerOf2(constant_abs - 1);
   1522           __ sll(scratch, left, shift);
   1523           __ Addu(result, scratch, left);
   1524           // Correct the sign of the result if the constant is negative.
   1525           if (constant < 0)  __ Subu(result, zero_reg, result);
   1526         } else if (base::bits::IsPowerOfTwo32(constant_abs + 1)) {
   1527           int32_t shift = WhichPowerOf2(constant_abs + 1);
   1528           __ sll(scratch, left, shift);
   1529           __ Subu(result, scratch, left);
   1530           // Correct the sign of the result if the constant is negative.
   1531           if (constant < 0)  __ Subu(result, zero_reg, result);
   1532         } else {
   1533           // Generate standard code.
   1534           __ li(at, constant);
   1535           __ Mul(result, left, at);
   1536         }
   1537     }
   1538 
   1539   } else {
   1540     DCHECK(right_op->IsRegister());
   1541     Register right = ToRegister(right_op);
   1542 
   1543     if (overflow) {
   1544       // hi:lo = left * right.
   1545       if (instr->hydrogen()->representation().IsSmi()) {
   1546         __ SmiUntag(result, left);
   1547         __ Mul(scratch, result, result, right);
   1548       } else {
   1549         __ Mul(scratch, result, left, right);
   1550       }
   1551       __ sra(at, result, 31);
   1552       DeoptimizeIf(ne, instr, scratch, Operand(at));
   1553     } else {
   1554       if (instr->hydrogen()->representation().IsSmi()) {
   1555         __ SmiUntag(result, left);
   1556         __ Mul(result, result, right);
   1557       } else {
   1558         __ Mul(result, left, right);
   1559       }
   1560     }
   1561 
   1562     if (bailout_on_minus_zero) {
   1563       Label done;
   1564       __ Xor(at, left, right);
   1565       __ Branch(&done, ge, at, Operand(zero_reg));
   1566       // Bail out if the result is minus zero.
   1567       DeoptimizeIf(eq, instr, result, Operand(zero_reg));
   1568       __ bind(&done);
   1569     }
   1570   }
   1571 }
   1572 
   1573 
   1574 void LCodeGen::DoBitI(LBitI* instr) {
   1575   LOperand* left_op = instr->left();
   1576   LOperand* right_op = instr->right();
   1577   DCHECK(left_op->IsRegister());
   1578   Register left = ToRegister(left_op);
   1579   Register result = ToRegister(instr->result());
   1580   Operand right(no_reg);
   1581 
   1582   if (right_op->IsStackSlot()) {
   1583     right = Operand(EmitLoadRegister(right_op, at));
   1584   } else {
   1585     DCHECK(right_op->IsRegister() || right_op->IsConstantOperand());
   1586     right = ToOperand(right_op);
   1587   }
   1588 
   1589   switch (instr->op()) {
   1590     case Token::BIT_AND:
   1591       __ And(result, left, right);
   1592       break;
   1593     case Token::BIT_OR:
   1594       __ Or(result, left, right);
   1595       break;
   1596     case Token::BIT_XOR:
   1597       if (right_op->IsConstantOperand() && right.immediate() == int32_t(~0)) {
   1598         __ Nor(result, zero_reg, left);
   1599       } else {
   1600         __ Xor(result, left, right);
   1601       }
   1602       break;
   1603     default:
   1604       UNREACHABLE();
   1605       break;
   1606   }
   1607 }
   1608 
   1609 
   1610 void LCodeGen::DoShiftI(LShiftI* instr) {
   1611   // Both 'left' and 'right' are "used at start" (see LCodeGen::DoShift), so
   1612   // result may alias either of them.
   1613   LOperand* right_op = instr->right();
   1614   Register left = ToRegister(instr->left());
   1615   Register result = ToRegister(instr->result());
   1616   Register scratch = scratch0();
   1617 
   1618   if (right_op->IsRegister()) {
   1619     // No need to mask the right operand on MIPS, it is built into the variable
   1620     // shift instructions.
   1621     switch (instr->op()) {
   1622       case Token::ROR:
   1623         __ Ror(result, left, Operand(ToRegister(right_op)));
   1624         break;
   1625       case Token::SAR:
   1626         __ srav(result, left, ToRegister(right_op));
   1627         break;
   1628       case Token::SHR:
   1629         __ srlv(result, left, ToRegister(right_op));
   1630         if (instr->can_deopt()) {
   1631           DeoptimizeIf(lt, instr, result, Operand(zero_reg));
   1632         }
   1633         break;
   1634       case Token::SHL:
   1635         __ sllv(result, left, ToRegister(right_op));
   1636         break;
   1637       default:
   1638         UNREACHABLE();
   1639         break;
   1640     }
   1641   } else {
   1642     // Mask the right_op operand.
   1643     int value = ToInteger32(LConstantOperand::cast(right_op));
   1644     uint8_t shift_count = static_cast<uint8_t>(value & 0x1F);
   1645     switch (instr->op()) {
   1646       case Token::ROR:
   1647         if (shift_count != 0) {
   1648           __ Ror(result, left, Operand(shift_count));
   1649         } else {
   1650           __ Move(result, left);
   1651         }
   1652         break;
   1653       case Token::SAR:
   1654         if (shift_count != 0) {
   1655           __ sra(result, left, shift_count);
   1656         } else {
   1657           __ Move(result, left);
   1658         }
   1659         break;
   1660       case Token::SHR:
   1661         if (shift_count != 0) {
   1662           __ srl(result, left, shift_count);
   1663         } else {
   1664           if (instr->can_deopt()) {
   1665             __ And(at, left, Operand(0x80000000));
   1666             DeoptimizeIf(ne, instr, at, Operand(zero_reg));
   1667           }
   1668           __ Move(result, left);
   1669         }
   1670         break;
   1671       case Token::SHL:
   1672         if (shift_count != 0) {
   1673           if (instr->hydrogen_value()->representation().IsSmi() &&
   1674               instr->can_deopt()) {
   1675             if (shift_count != 1) {
   1676               __ sll(result, left, shift_count - 1);
   1677               __ SmiTagCheckOverflow(result, result, scratch);
   1678             } else {
   1679               __ SmiTagCheckOverflow(result, left, scratch);
   1680             }
   1681             DeoptimizeIf(lt, instr, scratch, Operand(zero_reg));
   1682           } else {
   1683             __ sll(result, left, shift_count);
   1684           }
   1685         } else {
   1686           __ Move(result, left);
   1687         }
   1688         break;
   1689       default:
   1690         UNREACHABLE();
   1691         break;
   1692     }
   1693   }
   1694 }
   1695 
   1696 
   1697 void LCodeGen::DoSubI(LSubI* instr) {
   1698   LOperand* left = instr->left();
   1699   LOperand* right = instr->right();
   1700   LOperand* result = instr->result();
   1701   bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
   1702 
   1703   if (!can_overflow) {
   1704     if (right->IsStackSlot()) {
   1705       Register right_reg = EmitLoadRegister(right, at);
   1706       __ Subu(ToRegister(result), ToRegister(left), Operand(right_reg));
   1707     } else {
   1708       DCHECK(right->IsRegister() || right->IsConstantOperand());
   1709       __ Subu(ToRegister(result), ToRegister(left), ToOperand(right));
   1710     }
   1711   } else {  // can_overflow.
   1712     Register overflow = scratch0();
   1713     Register scratch = scratch1();
   1714     if (right->IsStackSlot() || right->IsConstantOperand()) {
   1715       Register right_reg = EmitLoadRegister(right, scratch);
   1716       __ SubuAndCheckForOverflow(ToRegister(result),
   1717                                  ToRegister(left),
   1718                                  right_reg,
   1719                                  overflow);  // Reg at also used as scratch.
   1720     } else {
   1721       DCHECK(right->IsRegister());
   1722       // Due to overflow check macros not supporting constant operands,
   1723       // handling the IsConstantOperand case was moved to prev if clause.
   1724       __ SubuAndCheckForOverflow(ToRegister(result),
   1725                                  ToRegister(left),
   1726                                  ToRegister(right),
   1727                                  overflow);  // Reg at also used as scratch.
   1728     }
   1729     DeoptimizeIf(lt, instr, overflow, Operand(zero_reg));
   1730   }
   1731 }
   1732 
   1733 
   1734 void LCodeGen::DoConstantI(LConstantI* instr) {
   1735   __ li(ToRegister(instr->result()), Operand(instr->value()));
   1736 }
   1737 
   1738 
   1739 void LCodeGen::DoConstantS(LConstantS* instr) {
   1740   __ li(ToRegister(instr->result()), Operand(instr->value()));
   1741 }
   1742 
   1743 
   1744 void LCodeGen::DoConstantD(LConstantD* instr) {
   1745   DCHECK(instr->result()->IsDoubleRegister());
   1746   DoubleRegister result = ToDoubleRegister(instr->result());
   1747   double v = instr->value();
   1748   __ Move(result, v);
   1749 }
   1750 
   1751 
   1752 void LCodeGen::DoConstantE(LConstantE* instr) {
   1753   __ li(ToRegister(instr->result()), Operand(instr->value()));
   1754 }
   1755 
   1756 
   1757 void LCodeGen::DoConstantT(LConstantT* instr) {
   1758   Handle<Object> object = instr->value(isolate());
   1759   AllowDeferredHandleDereference smi_check;
   1760   __ li(ToRegister(instr->result()), object);
   1761 }
   1762 
   1763 
   1764 void LCodeGen::DoMapEnumLength(LMapEnumLength* instr) {
   1765   Register result = ToRegister(instr->result());
   1766   Register map = ToRegister(instr->value());
   1767   __ EnumLength(result, map);
   1768 }
   1769 
   1770 
   1771 void LCodeGen::DoDateField(LDateField* instr) {
   1772   Register object = ToRegister(instr->date());
   1773   Register result = ToRegister(instr->result());
   1774   Register scratch = ToRegister(instr->temp());
   1775   Smi* index = instr->index();
   1776   Label runtime, done;
   1777   DCHECK(object.is(a0));
   1778   DCHECK(result.is(v0));
   1779   DCHECK(!scratch.is(scratch0()));
   1780   DCHECK(!scratch.is(object));
   1781 
   1782   __ SmiTst(object, at);
   1783   DeoptimizeIf(eq, instr, at, Operand(zero_reg));
   1784   __ GetObjectType(object, scratch, scratch);
   1785   DeoptimizeIf(ne, instr, scratch, Operand(JS_DATE_TYPE));
   1786 
   1787   if (index->value() == 0) {
   1788     __ lw(result, FieldMemOperand(object, JSDate::kValueOffset));
   1789   } else {
   1790     if (index->value() < JSDate::kFirstUncachedField) {
   1791       ExternalReference stamp = ExternalReference::date_cache_stamp(isolate());
   1792       __ li(scratch, Operand(stamp));
   1793       __ lw(scratch, MemOperand(scratch));
   1794       __ lw(scratch0(), FieldMemOperand(object, JSDate::kCacheStampOffset));
   1795       __ Branch(&runtime, ne, scratch, Operand(scratch0()));
   1796       __ lw(result, FieldMemOperand(object, JSDate::kValueOffset +
   1797                                             kPointerSize * index->value()));
   1798       __ jmp(&done);
   1799     }
   1800     __ bind(&runtime);
   1801     __ PrepareCallCFunction(2, scratch);
   1802     __ li(a1, Operand(index));
   1803     __ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2);
   1804     __ bind(&done);
   1805   }
   1806 }
   1807 
   1808 
   1809 MemOperand LCodeGen::BuildSeqStringOperand(Register string,
   1810                                            LOperand* index,
   1811                                            String::Encoding encoding) {
   1812   if (index->IsConstantOperand()) {
   1813     int offset = ToInteger32(LConstantOperand::cast(index));
   1814     if (encoding == String::TWO_BYTE_ENCODING) {
   1815       offset *= kUC16Size;
   1816     }
   1817     STATIC_ASSERT(kCharSize == 1);
   1818     return FieldMemOperand(string, SeqString::kHeaderSize + offset);
   1819   }
   1820   Register scratch = scratch0();
   1821   DCHECK(!scratch.is(string));
   1822   DCHECK(!scratch.is(ToRegister(index)));
   1823   if (encoding == String::ONE_BYTE_ENCODING) {
   1824     __ Addu(scratch, string, ToRegister(index));
   1825   } else {
   1826     STATIC_ASSERT(kUC16Size == 2);
   1827     __ sll(scratch, ToRegister(index), 1);
   1828     __ Addu(scratch, string, scratch);
   1829   }
   1830   return FieldMemOperand(scratch, SeqString::kHeaderSize);
   1831 }
   1832 
   1833 
   1834 void LCodeGen::DoSeqStringGetChar(LSeqStringGetChar* instr) {
   1835   String::Encoding encoding = instr->hydrogen()->encoding();
   1836   Register string = ToRegister(instr->string());
   1837   Register result = ToRegister(instr->result());
   1838 
   1839   if (FLAG_debug_code) {
   1840     Register scratch = scratch0();
   1841     __ lw(scratch, FieldMemOperand(string, HeapObject::kMapOffset));
   1842     __ lbu(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
   1843 
   1844     __ And(scratch, scratch,
   1845            Operand(kStringRepresentationMask | kStringEncodingMask));
   1846     static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
   1847     static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
   1848     __ Subu(at, scratch, Operand(encoding == String::ONE_BYTE_ENCODING
   1849                                 ? one_byte_seq_type : two_byte_seq_type));
   1850     __ Check(eq, kUnexpectedStringType, at, Operand(zero_reg));
   1851   }
   1852 
   1853   MemOperand operand = BuildSeqStringOperand(string, instr->index(), encoding);
   1854   if (encoding == String::ONE_BYTE_ENCODING) {
   1855     __ lbu(result, operand);
   1856   } else {
   1857     __ lhu(result, operand);
   1858   }
   1859 }
   1860 
   1861 
   1862 void LCodeGen::DoSeqStringSetChar(LSeqStringSetChar* instr) {
   1863   String::Encoding encoding = instr->hydrogen()->encoding();
   1864   Register string = ToRegister(instr->string());
   1865   Register value = ToRegister(instr->value());
   1866 
   1867   if (FLAG_debug_code) {
   1868     Register scratch = scratch0();
   1869     Register index = ToRegister(instr->index());
   1870     static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
   1871     static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
   1872     int encoding_mask =
   1873         instr->hydrogen()->encoding() == String::ONE_BYTE_ENCODING
   1874         ? one_byte_seq_type : two_byte_seq_type;
   1875     __ EmitSeqStringSetCharCheck(string, index, value, scratch, encoding_mask);
   1876   }
   1877 
   1878   MemOperand operand = BuildSeqStringOperand(string, instr->index(), encoding);
   1879   if (encoding == String::ONE_BYTE_ENCODING) {
   1880     __ sb(value, operand);
   1881   } else {
   1882     __ sh(value, operand);
   1883   }
   1884 }
   1885 
   1886 
   1887 void LCodeGen::DoAddI(LAddI* instr) {
   1888   LOperand* left = instr->left();
   1889   LOperand* right = instr->right();
   1890   LOperand* result = instr->result();
   1891   bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
   1892 
   1893   if (!can_overflow) {
   1894     if (right->IsStackSlot()) {
   1895       Register right_reg = EmitLoadRegister(right, at);
   1896       __ Addu(ToRegister(result), ToRegister(left), Operand(right_reg));
   1897     } else {
   1898       DCHECK(right->IsRegister() || right->IsConstantOperand());
   1899       __ Addu(ToRegister(result), ToRegister(left), ToOperand(right));
   1900     }
   1901   } else {  // can_overflow.
   1902     Register overflow = scratch0();
   1903     Register scratch = scratch1();
   1904     if (right->IsStackSlot() ||
   1905         right->IsConstantOperand()) {
   1906       Register right_reg = EmitLoadRegister(right, scratch);
   1907       __ AdduAndCheckForOverflow(ToRegister(result),
   1908                                  ToRegister(left),
   1909                                  right_reg,
   1910                                  overflow);  // Reg at also used as scratch.
   1911     } else {
   1912       DCHECK(right->IsRegister());
   1913       // Due to overflow check macros not supporting constant operands,
   1914       // handling the IsConstantOperand case was moved to prev if clause.
   1915       __ AdduAndCheckForOverflow(ToRegister(result),
   1916                                  ToRegister(left),
   1917                                  ToRegister(right),
   1918                                  overflow);  // Reg at also used as scratch.
   1919     }
   1920     DeoptimizeIf(lt, instr, overflow, Operand(zero_reg));
   1921   }
   1922 }
   1923 
   1924 
   1925 void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
   1926   LOperand* left = instr->left();
   1927   LOperand* right = instr->right();
   1928   HMathMinMax::Operation operation = instr->hydrogen()->operation();
   1929   Condition condition = (operation == HMathMinMax::kMathMin) ? le : ge;
   1930   if (instr->hydrogen()->representation().IsSmiOrInteger32()) {
   1931     Register left_reg = ToRegister(left);
   1932     Register right_reg = EmitLoadRegister(right, scratch0());
   1933     Register result_reg = ToRegister(instr->result());
   1934     Label return_right, done;
   1935     Register scratch = scratch1();
   1936     __ Slt(scratch, left_reg, Operand(right_reg));
   1937     if (condition == ge) {
   1938      __  Movz(result_reg, left_reg, scratch);
   1939      __  Movn(result_reg, right_reg, scratch);
   1940     } else {
   1941      DCHECK(condition == le);
   1942      __  Movn(result_reg, left_reg, scratch);
   1943      __  Movz(result_reg, right_reg, scratch);
   1944     }
   1945   } else {
   1946     DCHECK(instr->hydrogen()->representation().IsDouble());
   1947     FPURegister left_reg = ToDoubleRegister(left);
   1948     FPURegister right_reg = ToDoubleRegister(right);
   1949     FPURegister result_reg = ToDoubleRegister(instr->result());
   1950     Label check_nan_left, check_zero, return_left, return_right, done;
   1951     __ BranchF(&check_zero, &check_nan_left, eq, left_reg, right_reg);
   1952     __ BranchF(&return_left, NULL, condition, left_reg, right_reg);
   1953     __ Branch(&return_right);
   1954 
   1955     __ bind(&check_zero);
   1956     // left == right != 0.
   1957     __ BranchF(&return_left, NULL, ne, left_reg, kDoubleRegZero);
   1958     // At this point, both left and right are either 0 or -0.
   1959     if (operation == HMathMinMax::kMathMin) {
   1960       __ neg_d(left_reg, left_reg);
   1961       __ sub_d(result_reg, left_reg, right_reg);
   1962       __ neg_d(result_reg, result_reg);
   1963     } else {
   1964       __ add_d(result_reg, left_reg, right_reg);
   1965     }
   1966     __ Branch(&done);
   1967 
   1968     __ bind(&check_nan_left);
   1969     // left == NaN.
   1970     __ BranchF(NULL, &return_left, eq, left_reg, left_reg);
   1971     __ bind(&return_right);
   1972     if (!right_reg.is(result_reg)) {
   1973       __ mov_d(result_reg, right_reg);
   1974     }
   1975     __ Branch(&done);
   1976 
   1977     __ bind(&return_left);
   1978     if (!left_reg.is(result_reg)) {
   1979       __ mov_d(result_reg, left_reg);
   1980     }
   1981     __ bind(&done);
   1982   }
   1983 }
   1984 
   1985 
   1986 void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
   1987   DoubleRegister left = ToDoubleRegister(instr->left());
   1988   DoubleRegister right = ToDoubleRegister(instr->right());
   1989   DoubleRegister result = ToDoubleRegister(instr->result());
   1990   switch (instr->op()) {
   1991     case Token::ADD:
   1992       __ add_d(result, left, right);
   1993       break;
   1994     case Token::SUB:
   1995       __ sub_d(result, left, right);
   1996       break;
   1997     case Token::MUL:
   1998       __ mul_d(result, left, right);
   1999       break;
   2000     case Token::DIV:
   2001       __ div_d(result, left, right);
   2002       break;
   2003     case Token::MOD: {
   2004       // Save a0-a3 on the stack.
   2005       RegList saved_regs = a0.bit() | a1.bit() | a2.bit() | a3.bit();
   2006       __ MultiPush(saved_regs);
   2007 
   2008       __ PrepareCallCFunction(0, 2, scratch0());
   2009       __ MovToFloatParameters(left, right);
   2010       __ CallCFunction(
   2011           ExternalReference::mod_two_doubles_operation(isolate()),
   2012           0, 2);
   2013       // Move the result in the double result register.
   2014       __ MovFromFloatResult(result);
   2015 
   2016       // Restore saved register.
   2017       __ MultiPop(saved_regs);
   2018       break;
   2019     }
   2020     default:
   2021       UNREACHABLE();
   2022       break;
   2023   }
   2024 }
   2025 
   2026 
   2027 void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
   2028   DCHECK(ToRegister(instr->context()).is(cp));
   2029   DCHECK(ToRegister(instr->left()).is(a1));
   2030   DCHECK(ToRegister(instr->right()).is(a0));
   2031   DCHECK(ToRegister(instr->result()).is(v0));
   2032 
   2033   Handle<Code> code =
   2034       CodeFactory::BinaryOpIC(isolate(), instr->op(), NO_OVERWRITE).code();
   2035   CallCode(code, RelocInfo::CODE_TARGET, instr);
   2036   // Other arch use a nop here, to signal that there is no inlined
   2037   // patchable code. Mips does not need the nop, since our marker
   2038   // instruction (andi zero_reg) will never be used in normal code.
   2039 }
   2040 
   2041 
   2042 template<class InstrType>
   2043 void LCodeGen::EmitBranch(InstrType instr,
   2044                           Condition condition,
   2045                           Register src1,
   2046                           const Operand& src2) {
   2047   int left_block = instr->TrueDestination(chunk_);
   2048   int right_block = instr->FalseDestination(chunk_);
   2049 
   2050   int next_block = GetNextEmittedBlock();
   2051   if (right_block == left_block || condition == al) {
   2052     EmitGoto(left_block);
   2053   } else if (left_block == next_block) {
   2054     __ Branch(chunk_->GetAssemblyLabel(right_block),
   2055               NegateCondition(condition), src1, src2);
   2056   } else if (right_block == next_block) {
   2057     __ Branch(chunk_->GetAssemblyLabel(left_block), condition, src1, src2);
   2058   } else {
   2059     __ Branch(chunk_->GetAssemblyLabel(left_block), condition, src1, src2);
   2060     __ Branch(chunk_->GetAssemblyLabel(right_block));
   2061   }
   2062 }
   2063 
   2064 
   2065 template<class InstrType>
   2066 void LCodeGen::EmitBranchF(InstrType instr,
   2067                            Condition condition,
   2068                            FPURegister src1,
   2069                            FPURegister src2) {
   2070   int right_block = instr->FalseDestination(chunk_);
   2071   int left_block = instr->TrueDestination(chunk_);
   2072 
   2073   int next_block = GetNextEmittedBlock();
   2074   if (right_block == left_block) {
   2075     EmitGoto(left_block);
   2076   } else if (left_block == next_block) {
   2077     __ BranchF(chunk_->GetAssemblyLabel(right_block), NULL,
   2078                NegateCondition(condition), src1, src2);
   2079   } else if (right_block == next_block) {
   2080     __ BranchF(chunk_->GetAssemblyLabel(left_block), NULL,
   2081                condition, src1, src2);
   2082   } else {
   2083     __ BranchF(chunk_->GetAssemblyLabel(left_block), NULL,
   2084                condition, src1, src2);
   2085     __ Branch(chunk_->GetAssemblyLabel(right_block));
   2086   }
   2087 }
   2088 
   2089 
   2090 template<class InstrType>
   2091 void LCodeGen::EmitFalseBranch(InstrType instr,
   2092                                Condition condition,
   2093                                Register src1,
   2094                                const Operand& src2) {
   2095   int false_block = instr->FalseDestination(chunk_);
   2096   __ Branch(chunk_->GetAssemblyLabel(false_block), condition, src1, src2);
   2097 }
   2098 
   2099 
   2100 template<class InstrType>
   2101 void LCodeGen::EmitFalseBranchF(InstrType instr,
   2102                                 Condition condition,
   2103                                 FPURegister src1,
   2104                                 FPURegister src2) {
   2105   int false_block = instr->FalseDestination(chunk_);
   2106   __ BranchF(chunk_->GetAssemblyLabel(false_block), NULL,
   2107              condition, src1, src2);
   2108 }
   2109 
   2110 
   2111 void LCodeGen::DoDebugBreak(LDebugBreak* instr) {
   2112   __ stop("LDebugBreak");
   2113 }
   2114 
   2115 
   2116 void LCodeGen::DoBranch(LBranch* instr) {
   2117   Representation r = instr->hydrogen()->value()->representation();
   2118   if (r.IsInteger32() || r.IsSmi()) {
   2119     DCHECK(!info()->IsStub());
   2120     Register reg = ToRegister(instr->value());
   2121     EmitBranch(instr, ne, reg, Operand(zero_reg));
   2122   } else if (r.IsDouble()) {
   2123     DCHECK(!info()->IsStub());
   2124     DoubleRegister reg = ToDoubleRegister(instr->value());
   2125     // Test the double value. Zero and NaN are false.
   2126     EmitBranchF(instr, nue, reg, kDoubleRegZero);
   2127   } else {
   2128     DCHECK(r.IsTagged());
   2129     Register reg = ToRegister(instr->value());
   2130     HType type = instr->hydrogen()->value()->type();
   2131     if (type.IsBoolean()) {
   2132       DCHECK(!info()->IsStub());
   2133       __ LoadRoot(at, Heap::kTrueValueRootIndex);
   2134       EmitBranch(instr, eq, reg, Operand(at));
   2135     } else if (type.IsSmi()) {
   2136       DCHECK(!info()->IsStub());
   2137       EmitBranch(instr, ne, reg, Operand(zero_reg));
   2138     } else if (type.IsJSArray()) {
   2139       DCHECK(!info()->IsStub());
   2140       EmitBranch(instr, al, zero_reg, Operand(zero_reg));
   2141     } else if (type.IsHeapNumber()) {
   2142       DCHECK(!info()->IsStub());
   2143       DoubleRegister dbl_scratch = double_scratch0();
   2144       __ ldc1(dbl_scratch, FieldMemOperand(reg, HeapNumber::kValueOffset));
   2145       // Test the double value. Zero and NaN are false.
   2146       EmitBranchF(instr, nue, dbl_scratch, kDoubleRegZero);
   2147     } else if (type.IsString()) {
   2148       DCHECK(!info()->IsStub());
   2149       __ lw(at, FieldMemOperand(reg, String::kLengthOffset));
   2150       EmitBranch(instr, ne, at, Operand(zero_reg));
   2151     } else {
   2152       ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
   2153       // Avoid deopts in the case where we've never executed this path before.
   2154       if (expected.IsEmpty()) expected = ToBooleanStub::Types::Generic();
   2155 
   2156       if (expected.Contains(ToBooleanStub::UNDEFINED)) {
   2157         // undefined -> false.
   2158         __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   2159         __ Branch(instr->FalseLabel(chunk_), eq, reg, Operand(at));
   2160       }
   2161       if (expected.Contains(ToBooleanStub::BOOLEAN)) {
   2162         // Boolean -> its value.
   2163         __ LoadRoot(at, Heap::kTrueValueRootIndex);
   2164         __ Branch(instr->TrueLabel(chunk_), eq, reg, Operand(at));
   2165         __ LoadRoot(at, Heap::kFalseValueRootIndex);
   2166         __ Branch(instr->FalseLabel(chunk_), eq, reg, Operand(at));
   2167       }
   2168       if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
   2169         // 'null' -> false.
   2170         __ LoadRoot(at, Heap::kNullValueRootIndex);
   2171         __ Branch(instr->FalseLabel(chunk_), eq, reg, Operand(at));
   2172       }
   2173 
   2174       if (expected.Contains(ToBooleanStub::SMI)) {
   2175         // Smis: 0 -> false, all other -> true.
   2176         __ Branch(instr->FalseLabel(chunk_), eq, reg, Operand(zero_reg));
   2177         __ JumpIfSmi(reg, instr->TrueLabel(chunk_));
   2178       } else if (expected.NeedsMap()) {
   2179         // If we need a map later and have a Smi -> deopt.
   2180         __ SmiTst(reg, at);
   2181         DeoptimizeIf(eq, instr, at, Operand(zero_reg));
   2182       }
   2183 
   2184       const Register map = scratch0();
   2185       if (expected.NeedsMap()) {
   2186         __ lw(map, FieldMemOperand(reg, HeapObject::kMapOffset));
   2187         if (expected.CanBeUndetectable()) {
   2188           // Undetectable -> false.
   2189           __ lbu(at, FieldMemOperand(map, Map::kBitFieldOffset));
   2190           __ And(at, at, Operand(1 << Map::kIsUndetectable));
   2191           __ Branch(instr->FalseLabel(chunk_), ne, at, Operand(zero_reg));
   2192         }
   2193       }
   2194 
   2195       if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
   2196         // spec object -> true.
   2197         __ lbu(at, FieldMemOperand(map, Map::kInstanceTypeOffset));
   2198         __ Branch(instr->TrueLabel(chunk_),
   2199                   ge, at, Operand(FIRST_SPEC_OBJECT_TYPE));
   2200       }
   2201 
   2202       if (expected.Contains(ToBooleanStub::STRING)) {
   2203         // String value -> false iff empty.
   2204         Label not_string;
   2205         __ lbu(at, FieldMemOperand(map, Map::kInstanceTypeOffset));
   2206         __ Branch(&not_string, ge , at, Operand(FIRST_NONSTRING_TYPE));
   2207         __ lw(at, FieldMemOperand(reg, String::kLengthOffset));
   2208         __ Branch(instr->TrueLabel(chunk_), ne, at, Operand(zero_reg));
   2209         __ Branch(instr->FalseLabel(chunk_));
   2210         __ bind(&not_string);
   2211       }
   2212 
   2213       if (expected.Contains(ToBooleanStub::SYMBOL)) {
   2214         // Symbol value -> true.
   2215         const Register scratch = scratch1();
   2216         __ lbu(scratch, FieldMemOperand(map, Map::kInstanceTypeOffset));
   2217         __ Branch(instr->TrueLabel(chunk_), eq, scratch, Operand(SYMBOL_TYPE));
   2218       }
   2219 
   2220       if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
   2221         // heap number -> false iff +0, -0, or NaN.
   2222         DoubleRegister dbl_scratch = double_scratch0();
   2223         Label not_heap_number;
   2224         __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
   2225         __ Branch(&not_heap_number, ne, map, Operand(at));
   2226         __ ldc1(dbl_scratch, FieldMemOperand(reg, HeapNumber::kValueOffset));
   2227         __ BranchF(instr->TrueLabel(chunk_), instr->FalseLabel(chunk_),
   2228                    ne, dbl_scratch, kDoubleRegZero);
   2229         // Falls through if dbl_scratch == 0.
   2230         __ Branch(instr->FalseLabel(chunk_));
   2231         __ bind(&not_heap_number);
   2232       }
   2233 
   2234       if (!expected.IsGeneric()) {
   2235         // We've seen something for the first time -> deopt.
   2236         // This can only happen if we are not generic already.
   2237         DeoptimizeIf(al, instr, zero_reg, Operand(zero_reg));
   2238       }
   2239     }
   2240   }
   2241 }
   2242 
   2243 
   2244 void LCodeGen::EmitGoto(int block) {
   2245   if (!IsNextEmittedBlock(block)) {
   2246     __ jmp(chunk_->GetAssemblyLabel(LookupDestination(block)));
   2247   }
   2248 }
   2249 
   2250 
   2251 void LCodeGen::DoGoto(LGoto* instr) {
   2252   EmitGoto(instr->block_id());
   2253 }
   2254 
   2255 
   2256 Condition LCodeGen::TokenToCondition(Token::Value op, bool is_unsigned) {
   2257   Condition cond = kNoCondition;
   2258   switch (op) {
   2259     case Token::EQ:
   2260     case Token::EQ_STRICT:
   2261       cond = eq;
   2262       break;
   2263     case Token::NE:
   2264     case Token::NE_STRICT:
   2265       cond = ne;
   2266       break;
   2267     case Token::LT:
   2268       cond = is_unsigned ? lo : lt;
   2269       break;
   2270     case Token::GT:
   2271       cond = is_unsigned ? hi : gt;
   2272       break;
   2273     case Token::LTE:
   2274       cond = is_unsigned ? ls : le;
   2275       break;
   2276     case Token::GTE:
   2277       cond = is_unsigned ? hs : ge;
   2278       break;
   2279     case Token::IN:
   2280     case Token::INSTANCEOF:
   2281     default:
   2282       UNREACHABLE();
   2283   }
   2284   return cond;
   2285 }
   2286 
   2287 
   2288 void LCodeGen::DoCompareNumericAndBranch(LCompareNumericAndBranch* instr) {
   2289   LOperand* left = instr->left();
   2290   LOperand* right = instr->right();
   2291   bool is_unsigned =
   2292       instr->hydrogen()->left()->CheckFlag(HInstruction::kUint32) ||
   2293       instr->hydrogen()->right()->CheckFlag(HInstruction::kUint32);
   2294   Condition cond = TokenToCondition(instr->op(), is_unsigned);
   2295 
   2296   if (left->IsConstantOperand() && right->IsConstantOperand()) {
   2297     // We can statically evaluate the comparison.
   2298     double left_val = ToDouble(LConstantOperand::cast(left));
   2299     double right_val = ToDouble(LConstantOperand::cast(right));
   2300     int next_block = EvalComparison(instr->op(), left_val, right_val) ?
   2301         instr->TrueDestination(chunk_) : instr->FalseDestination(chunk_);
   2302     EmitGoto(next_block);
   2303   } else {
   2304     if (instr->is_double()) {
   2305       // Compare left and right as doubles and load the
   2306       // resulting flags into the normal status register.
   2307       FPURegister left_reg = ToDoubleRegister(left);
   2308       FPURegister right_reg = ToDoubleRegister(right);
   2309 
   2310       // If a NaN is involved, i.e. the result is unordered,
   2311       // jump to false block label.
   2312       __ BranchF(NULL, instr->FalseLabel(chunk_), eq,
   2313                  left_reg, right_reg);
   2314 
   2315       EmitBranchF(instr, cond, left_reg, right_reg);
   2316     } else {
   2317       Register cmp_left;
   2318       Operand cmp_right = Operand(0);
   2319 
   2320       if (right->IsConstantOperand()) {
   2321         int32_t value = ToInteger32(LConstantOperand::cast(right));
   2322         if (instr->hydrogen_value()->representation().IsSmi()) {
   2323           cmp_left = ToRegister(left);
   2324           cmp_right = Operand(Smi::FromInt(value));
   2325         } else {
   2326           cmp_left = ToRegister(left);
   2327           cmp_right = Operand(value);
   2328         }
   2329       } else if (left->IsConstantOperand()) {
   2330         int32_t value = ToInteger32(LConstantOperand::cast(left));
   2331         if (instr->hydrogen_value()->representation().IsSmi()) {
   2332            cmp_left = ToRegister(right);
   2333            cmp_right = Operand(Smi::FromInt(value));
   2334         } else {
   2335           cmp_left = ToRegister(right);
   2336           cmp_right = Operand(value);
   2337         }
   2338         // We commuted the operands, so commute the condition.
   2339         cond = CommuteCondition(cond);
   2340       } else {
   2341         cmp_left = ToRegister(left);
   2342         cmp_right = Operand(ToRegister(right));
   2343       }
   2344 
   2345       EmitBranch(instr, cond, cmp_left, cmp_right);
   2346     }
   2347   }
   2348 }
   2349 
   2350 
   2351 void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
   2352   Register left = ToRegister(instr->left());
   2353   Register right = ToRegister(instr->right());
   2354 
   2355   EmitBranch(instr, eq, left, Operand(right));
   2356 }
   2357 
   2358 
   2359 void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
   2360   if (instr->hydrogen()->representation().IsTagged()) {
   2361     Register input_reg = ToRegister(instr->object());
   2362     __ li(at, Operand(factory()->the_hole_value()));
   2363     EmitBranch(instr, eq, input_reg, Operand(at));
   2364     return;
   2365   }
   2366 
   2367   DoubleRegister input_reg = ToDoubleRegister(instr->object());
   2368   EmitFalseBranchF(instr, eq, input_reg, input_reg);
   2369 
   2370   Register scratch = scratch0();
   2371   __ FmoveHigh(scratch, input_reg);
   2372   EmitBranch(instr, eq, scratch, Operand(kHoleNanUpper32));
   2373 }
   2374 
   2375 
   2376 void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
   2377   Representation rep = instr->hydrogen()->value()->representation();
   2378   DCHECK(!rep.IsInteger32());
   2379   Register scratch = ToRegister(instr->temp());
   2380 
   2381   if (rep.IsDouble()) {
   2382     DoubleRegister value = ToDoubleRegister(instr->value());
   2383     EmitFalseBranchF(instr, ne, value, kDoubleRegZero);
   2384     __ FmoveHigh(scratch, value);
   2385     __ li(at, 0x80000000);
   2386   } else {
   2387     Register value = ToRegister(instr->value());
   2388     __ CheckMap(value,
   2389                 scratch,
   2390                 Heap::kHeapNumberMapRootIndex,
   2391                 instr->FalseLabel(chunk()),
   2392                 DO_SMI_CHECK);
   2393     __ lw(scratch, FieldMemOperand(value, HeapNumber::kExponentOffset));
   2394     EmitFalseBranch(instr, ne, scratch, Operand(0x80000000));
   2395     __ lw(scratch, FieldMemOperand(value, HeapNumber::kMantissaOffset));
   2396     __ mov(at, zero_reg);
   2397   }
   2398   EmitBranch(instr, eq, scratch, Operand(at));
   2399 }
   2400 
   2401 
   2402 Condition LCodeGen::EmitIsObject(Register input,
   2403                                  Register temp1,
   2404                                  Register temp2,
   2405                                  Label* is_not_object,
   2406                                  Label* is_object) {
   2407   __ JumpIfSmi(input, is_not_object);
   2408 
   2409   __ LoadRoot(temp2, Heap::kNullValueRootIndex);
   2410   __ Branch(is_object, eq, input, Operand(temp2));
   2411 
   2412   // Load map.
   2413   __ lw(temp1, FieldMemOperand(input, HeapObject::kMapOffset));
   2414   // Undetectable objects behave like undefined.
   2415   __ lbu(temp2, FieldMemOperand(temp1, Map::kBitFieldOffset));
   2416   __ And(temp2, temp2, Operand(1 << Map::kIsUndetectable));
   2417   __ Branch(is_not_object, ne, temp2, Operand(zero_reg));
   2418 
   2419   // Load instance type and check that it is in object type range.
   2420   __ lbu(temp2, FieldMemOperand(temp1, Map::kInstanceTypeOffset));
   2421   __ Branch(is_not_object,
   2422             lt, temp2, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
   2423 
   2424   return le;
   2425 }
   2426 
   2427 
   2428 void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
   2429   Register reg = ToRegister(instr->value());
   2430   Register temp1 = ToRegister(instr->temp());
   2431   Register temp2 = scratch0();
   2432 
   2433   Condition true_cond =
   2434       EmitIsObject(reg, temp1, temp2,
   2435           instr->FalseLabel(chunk_), instr->TrueLabel(chunk_));
   2436 
   2437   EmitBranch(instr, true_cond, temp2,
   2438              Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
   2439 }
   2440 
   2441 
   2442 Condition LCodeGen::EmitIsString(Register input,
   2443                                  Register temp1,
   2444                                  Label* is_not_string,
   2445                                  SmiCheck check_needed = INLINE_SMI_CHECK) {
   2446   if (check_needed == INLINE_SMI_CHECK) {
   2447     __ JumpIfSmi(input, is_not_string);
   2448   }
   2449   __ GetObjectType(input, temp1, temp1);
   2450 
   2451   return lt;
   2452 }
   2453 
   2454 
   2455 void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
   2456   Register reg = ToRegister(instr->value());
   2457   Register temp1 = ToRegister(instr->temp());
   2458 
   2459   SmiCheck check_needed =
   2460       instr->hydrogen()->value()->type().IsHeapObject()
   2461           ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
   2462   Condition true_cond =
   2463       EmitIsString(reg, temp1, instr->FalseLabel(chunk_), check_needed);
   2464 
   2465   EmitBranch(instr, true_cond, temp1,
   2466              Operand(FIRST_NONSTRING_TYPE));
   2467 }
   2468 
   2469 
   2470 void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
   2471   Register input_reg = EmitLoadRegister(instr->value(), at);
   2472   __ And(at, input_reg, kSmiTagMask);
   2473   EmitBranch(instr, eq, at, Operand(zero_reg));
   2474 }
   2475 
   2476 
   2477 void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
   2478   Register input = ToRegister(instr->value());
   2479   Register temp = ToRegister(instr->temp());
   2480 
   2481   if (!instr->hydrogen()->value()->type().IsHeapObject()) {
   2482     __ JumpIfSmi(input, instr->FalseLabel(chunk_));
   2483   }
   2484   __ lw(temp, FieldMemOperand(input, HeapObject::kMapOffset));
   2485   __ lbu(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
   2486   __ And(at, temp, Operand(1 << Map::kIsUndetectable));
   2487   EmitBranch(instr, ne, at, Operand(zero_reg));
   2488 }
   2489 
   2490 
   2491 static Condition ComputeCompareCondition(Token::Value op) {
   2492   switch (op) {
   2493     case Token::EQ_STRICT:
   2494     case Token::EQ:
   2495       return eq;
   2496     case Token::LT:
   2497       return lt;
   2498     case Token::GT:
   2499       return gt;
   2500     case Token::LTE:
   2501       return le;
   2502     case Token::GTE:
   2503       return ge;
   2504     default:
   2505       UNREACHABLE();
   2506       return kNoCondition;
   2507   }
   2508 }
   2509 
   2510 
   2511 void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
   2512   DCHECK(ToRegister(instr->context()).is(cp));
   2513   Token::Value op = instr->op();
   2514 
   2515   Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
   2516   CallCode(ic, RelocInfo::CODE_TARGET, instr);
   2517 
   2518   Condition condition = ComputeCompareCondition(op);
   2519 
   2520   EmitBranch(instr, condition, v0, Operand(zero_reg));
   2521 }
   2522 
   2523 
   2524 static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
   2525   InstanceType from = instr->from();
   2526   InstanceType to = instr->to();
   2527   if (from == FIRST_TYPE) return to;
   2528   DCHECK(from == to || to == LAST_TYPE);
   2529   return from;
   2530 }
   2531 
   2532 
   2533 static Condition BranchCondition(HHasInstanceTypeAndBranch* instr) {
   2534   InstanceType from = instr->from();
   2535   InstanceType to = instr->to();
   2536   if (from == to) return eq;
   2537   if (to == LAST_TYPE) return hs;
   2538   if (from == FIRST_TYPE) return ls;
   2539   UNREACHABLE();
   2540   return eq;
   2541 }
   2542 
   2543 
   2544 void LCodeGen::DoHasInstanceTypeAndBranch(LHasInstanceTypeAndBranch* instr) {
   2545   Register scratch = scratch0();
   2546   Register input = ToRegister(instr->value());
   2547 
   2548   if (!instr->hydrogen()->value()->type().IsHeapObject()) {
   2549     __ JumpIfSmi(input, instr->FalseLabel(chunk_));
   2550   }
   2551 
   2552   __ GetObjectType(input, scratch, scratch);
   2553   EmitBranch(instr,
   2554              BranchCondition(instr->hydrogen()),
   2555              scratch,
   2556              Operand(TestType(instr->hydrogen())));
   2557 }
   2558 
   2559 
   2560 void LCodeGen::DoGetCachedArrayIndex(LGetCachedArrayIndex* instr) {
   2561   Register input = ToRegister(instr->value());
   2562   Register result = ToRegister(instr->result());
   2563 
   2564   __ AssertString(input);
   2565 
   2566   __ lw(result, FieldMemOperand(input, String::kHashFieldOffset));
   2567   __ IndexFromHash(result, result);
   2568 }
   2569 
   2570 
   2571 void LCodeGen::DoHasCachedArrayIndexAndBranch(
   2572     LHasCachedArrayIndexAndBranch* instr) {
   2573   Register input = ToRegister(instr->value());
   2574   Register scratch = scratch0();
   2575 
   2576   __ lw(scratch,
   2577          FieldMemOperand(input, String::kHashFieldOffset));
   2578   __ And(at, scratch, Operand(String::kContainsCachedArrayIndexMask));
   2579   EmitBranch(instr, eq, at, Operand(zero_reg));
   2580 }
   2581 
   2582 
   2583 // Branches to a label or falls through with the answer in flags.  Trashes
   2584 // the temp registers, but not the input.
   2585 void LCodeGen::EmitClassOfTest(Label* is_true,
   2586                                Label* is_false,
   2587                                Handle<String>class_name,
   2588                                Register input,
   2589                                Register temp,
   2590                                Register temp2) {
   2591   DCHECK(!input.is(temp));
   2592   DCHECK(!input.is(temp2));
   2593   DCHECK(!temp.is(temp2));
   2594 
   2595   __ JumpIfSmi(input, is_false);
   2596 
   2597   if (String::Equals(isolate()->factory()->Function_string(), class_name)) {
   2598     // Assuming the following assertions, we can use the same compares to test
   2599     // for both being a function type and being in the object type range.
   2600     STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
   2601     STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
   2602                   FIRST_SPEC_OBJECT_TYPE + 1);
   2603     STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
   2604                   LAST_SPEC_OBJECT_TYPE - 1);
   2605     STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
   2606 
   2607     __ GetObjectType(input, temp, temp2);
   2608     __ Branch(is_false, lt, temp2, Operand(FIRST_SPEC_OBJECT_TYPE));
   2609     __ Branch(is_true, eq, temp2, Operand(FIRST_SPEC_OBJECT_TYPE));
   2610     __ Branch(is_true, eq, temp2, Operand(LAST_SPEC_OBJECT_TYPE));
   2611   } else {
   2612     // Faster code path to avoid two compares: subtract lower bound from the
   2613     // actual type and do a signed compare with the width of the type range.
   2614     __ GetObjectType(input, temp, temp2);
   2615     __ Subu(temp2, temp2, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
   2616     __ Branch(is_false, gt, temp2, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE -
   2617                                            FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
   2618   }
   2619 
   2620   // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
   2621   // Check if the constructor in the map is a function.
   2622   __ lw(temp, FieldMemOperand(temp, Map::kConstructorOffset));
   2623 
   2624   // Objects with a non-function constructor have class 'Object'.
   2625   __ GetObjectType(temp, temp2, temp2);
   2626   if (String::Equals(class_name, isolate()->factory()->Object_string())) {
   2627     __ Branch(is_true, ne, temp2, Operand(JS_FUNCTION_TYPE));
   2628   } else {
   2629     __ Branch(is_false, ne, temp2, Operand(JS_FUNCTION_TYPE));
   2630   }
   2631 
   2632   // temp now contains the constructor function. Grab the
   2633   // instance class name from there.
   2634   __ lw(temp, FieldMemOperand(temp, JSFunction::kSharedFunctionInfoOffset));
   2635   __ lw(temp, FieldMemOperand(temp,
   2636                                SharedFunctionInfo::kInstanceClassNameOffset));
   2637   // The class name we are testing against is internalized since it's a literal.
   2638   // The name in the constructor is internalized because of the way the context
   2639   // is booted.  This routine isn't expected to work for random API-created
   2640   // classes and it doesn't have to because you can't access it with natives
   2641   // syntax.  Since both sides are internalized it is sufficient to use an
   2642   // identity comparison.
   2643 
   2644   // End with the address of this class_name instance in temp register.
   2645   // On MIPS, the caller must do the comparison with Handle<String>class_name.
   2646 }
   2647 
   2648 
   2649 void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
   2650   Register input = ToRegister(instr->value());
   2651   Register temp = scratch0();
   2652   Register temp2 = ToRegister(instr->temp());
   2653   Handle<String> class_name = instr->hydrogen()->class_name();
   2654 
   2655   EmitClassOfTest(instr->TrueLabel(chunk_), instr->FalseLabel(chunk_),
   2656                   class_name, input, temp, temp2);
   2657 
   2658   EmitBranch(instr, eq, temp, Operand(class_name));
   2659 }
   2660 
   2661 
   2662 void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
   2663   Register reg = ToRegister(instr->value());
   2664   Register temp = ToRegister(instr->temp());
   2665 
   2666   __ lw(temp, FieldMemOperand(reg, HeapObject::kMapOffset));
   2667   EmitBranch(instr, eq, temp, Operand(instr->map()));
   2668 }
   2669 
   2670 
   2671 void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
   2672   DCHECK(ToRegister(instr->context()).is(cp));
   2673   Label true_label, done;
   2674   DCHECK(ToRegister(instr->left()).is(a0));  // Object is in a0.
   2675   DCHECK(ToRegister(instr->right()).is(a1));  // Function is in a1.
   2676   Register result = ToRegister(instr->result());
   2677   DCHECK(result.is(v0));
   2678 
   2679   InstanceofStub stub(isolate(), InstanceofStub::kArgsInRegisters);
   2680   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   2681 
   2682   __ Branch(&true_label, eq, result, Operand(zero_reg));
   2683   __ li(result, Operand(factory()->false_value()));
   2684   __ Branch(&done);
   2685   __ bind(&true_label);
   2686   __ li(result, Operand(factory()->true_value()));
   2687   __ bind(&done);
   2688 }
   2689 
   2690 
   2691 void LCodeGen::DoInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr) {
   2692   class DeferredInstanceOfKnownGlobal FINAL : public LDeferredCode {
   2693    public:
   2694     DeferredInstanceOfKnownGlobal(LCodeGen* codegen,
   2695                                   LInstanceOfKnownGlobal* instr)
   2696         : LDeferredCode(codegen), instr_(instr) { }
   2697     virtual void Generate() OVERRIDE {
   2698       codegen()->DoDeferredInstanceOfKnownGlobal(instr_, &map_check_);
   2699     }
   2700     virtual LInstruction* instr() OVERRIDE { return instr_; }
   2701     Label* map_check() { return &map_check_; }
   2702 
   2703    private:
   2704     LInstanceOfKnownGlobal* instr_;
   2705     Label map_check_;
   2706   };
   2707 
   2708   DeferredInstanceOfKnownGlobal* deferred;
   2709   deferred = new(zone()) DeferredInstanceOfKnownGlobal(this, instr);
   2710 
   2711   Label done, false_result;
   2712   Register object = ToRegister(instr->value());
   2713   Register temp = ToRegister(instr->temp());
   2714   Register result = ToRegister(instr->result());
   2715 
   2716   DCHECK(object.is(a0));
   2717   DCHECK(result.is(v0));
   2718 
   2719   // A Smi is not instance of anything.
   2720   __ JumpIfSmi(object, &false_result);
   2721 
   2722   // This is the inlined call site instanceof cache. The two occurences of the
   2723   // hole value will be patched to the last map/result pair generated by the
   2724   // instanceof stub.
   2725   Label cache_miss;
   2726   Register map = temp;
   2727   __ lw(map, FieldMemOperand(object, HeapObject::kMapOffset));
   2728 
   2729   Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
   2730   __ bind(deferred->map_check());  // Label for calculating code patching.
   2731   // We use Factory::the_hole_value() on purpose instead of loading from the
   2732   // root array to force relocation to be able to later patch with
   2733   // the cached map.
   2734   Handle<Cell> cell = factory()->NewCell(factory()->the_hole_value());
   2735   __ li(at, Operand(Handle<Object>(cell)));
   2736   __ lw(at, FieldMemOperand(at, PropertyCell::kValueOffset));
   2737   __ BranchShort(&cache_miss, ne, map, Operand(at));
   2738   // We use Factory::the_hole_value() on purpose instead of loading from the
   2739   // root array to force relocation to be able to later patch
   2740   // with true or false. The distance from map check has to be constant.
   2741   __ li(result, Operand(factory()->the_hole_value()), CONSTANT_SIZE);
   2742   __ Branch(&done);
   2743 
   2744   // The inlined call site cache did not match. Check null and string before
   2745   // calling the deferred code.
   2746   __ bind(&cache_miss);
   2747   // Null is not instance of anything.
   2748   __ LoadRoot(temp, Heap::kNullValueRootIndex);
   2749   __ Branch(&false_result, eq, object, Operand(temp));
   2750 
   2751   // String values is not instance of anything.
   2752   Condition cc = __ IsObjectStringType(object, temp, temp);
   2753   __ Branch(&false_result, cc, temp, Operand(zero_reg));
   2754 
   2755   // Go to the deferred code.
   2756   __ Branch(deferred->entry());
   2757 
   2758   __ bind(&false_result);
   2759   __ LoadRoot(result, Heap::kFalseValueRootIndex);
   2760 
   2761   // Here result has either true or false. Deferred code also produces true or
   2762   // false object.
   2763   __ bind(deferred->exit());
   2764   __ bind(&done);
   2765 }
   2766 
   2767 
   2768 void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
   2769                                                Label* map_check) {
   2770   Register result = ToRegister(instr->result());
   2771   DCHECK(result.is(v0));
   2772 
   2773   InstanceofStub::Flags flags = InstanceofStub::kNoFlags;
   2774   flags = static_cast<InstanceofStub::Flags>(
   2775       flags | InstanceofStub::kArgsInRegisters);
   2776   flags = static_cast<InstanceofStub::Flags>(
   2777       flags | InstanceofStub::kCallSiteInlineCheck);
   2778   flags = static_cast<InstanceofStub::Flags>(
   2779       flags | InstanceofStub::kReturnTrueFalseObject);
   2780   InstanceofStub stub(isolate(), flags);
   2781 
   2782   PushSafepointRegistersScope scope(this);
   2783   LoadContextFromDeferred(instr->context());
   2784 
   2785   // Get the temp register reserved by the instruction. This needs to be t0 as
   2786   // its slot of the pushing of safepoint registers is used to communicate the
   2787   // offset to the location of the map check.
   2788   Register temp = ToRegister(instr->temp());
   2789   DCHECK(temp.is(t0));
   2790   __ li(InstanceofStub::right(), instr->function());
   2791   static const int kAdditionalDelta = 7;
   2792   int delta = masm_->InstructionsGeneratedSince(map_check) + kAdditionalDelta;
   2793   Label before_push_delta;
   2794   __ bind(&before_push_delta);
   2795   {
   2796     Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
   2797     __ li(temp, Operand(delta * kPointerSize), CONSTANT_SIZE);
   2798     __ StoreToSafepointRegisterSlot(temp, temp);
   2799   }
   2800   CallCodeGeneric(stub.GetCode(),
   2801                   RelocInfo::CODE_TARGET,
   2802                   instr,
   2803                   RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
   2804   LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
   2805   safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
   2806   // Put the result value into the result register slot and
   2807   // restore all registers.
   2808   __ StoreToSafepointRegisterSlot(result, result);
   2809 }
   2810 
   2811 
   2812 void LCodeGen::DoCmpT(LCmpT* instr) {
   2813   DCHECK(ToRegister(instr->context()).is(cp));
   2814   Token::Value op = instr->op();
   2815 
   2816   Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
   2817   CallCode(ic, RelocInfo::CODE_TARGET, instr);
   2818   // On MIPS there is no need for a "no inlined smi code" marker (nop).
   2819 
   2820   Condition condition = ComputeCompareCondition(op);
   2821   // A minor optimization that relies on LoadRoot always emitting one
   2822   // instruction.
   2823   Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm());
   2824   Label done, check;
   2825   __ Branch(USE_DELAY_SLOT, &done, condition, v0, Operand(zero_reg));
   2826   __ bind(&check);
   2827   __ LoadRoot(ToRegister(instr->result()), Heap::kTrueValueRootIndex);
   2828   DCHECK_EQ(1, masm()->InstructionsGeneratedSince(&check));
   2829   __ LoadRoot(ToRegister(instr->result()), Heap::kFalseValueRootIndex);
   2830   __ bind(&done);
   2831 }
   2832 
   2833 
   2834 void LCodeGen::DoReturn(LReturn* instr) {
   2835   if (FLAG_trace && info()->IsOptimizing()) {
   2836     // Push the return value on the stack as the parameter.
   2837     // Runtime::TraceExit returns its parameter in v0. We're leaving the code
   2838     // managed by the register allocator and tearing down the frame, it's
   2839     // safe to write to the context register.
   2840     __ push(v0);
   2841     __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   2842     __ CallRuntime(Runtime::kTraceExit, 1);
   2843   }
   2844   if (info()->saves_caller_doubles()) {
   2845     RestoreCallerDoubles();
   2846   }
   2847   int no_frame_start = -1;
   2848   if (NeedsEagerFrame()) {
   2849     __ mov(sp, fp);
   2850     no_frame_start = masm_->pc_offset();
   2851     __ Pop(ra, fp);
   2852   }
   2853   if (instr->has_constant_parameter_count()) {
   2854     int parameter_count = ToInteger32(instr->constant_parameter_count());
   2855     int32_t sp_delta = (parameter_count + 1) * kPointerSize;
   2856     if (sp_delta != 0) {
   2857       __ Addu(sp, sp, Operand(sp_delta));
   2858     }
   2859   } else {
   2860     Register reg = ToRegister(instr->parameter_count());
   2861     // The argument count parameter is a smi
   2862     __ SmiUntag(reg);
   2863     __ sll(at, reg, kPointerSizeLog2);
   2864     __ Addu(sp, sp, at);
   2865   }
   2866 
   2867   __ Jump(ra);
   2868 
   2869   if (no_frame_start != -1) {
   2870     info_->AddNoFrameRange(no_frame_start, masm_->pc_offset());
   2871   }
   2872 }
   2873 
   2874 
   2875 void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
   2876   Register result = ToRegister(instr->result());
   2877   __ li(at, Operand(Handle<Object>(instr->hydrogen()->cell().handle())));
   2878   __ lw(result, FieldMemOperand(at, Cell::kValueOffset));
   2879   if (instr->hydrogen()->RequiresHoleCheck()) {
   2880     __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
   2881     DeoptimizeIf(eq, instr, result, Operand(at));
   2882   }
   2883 }
   2884 
   2885 
   2886 template <class T>
   2887 void LCodeGen::EmitVectorLoadICRegisters(T* instr) {
   2888   DCHECK(FLAG_vector_ics);
   2889   Register vector = ToRegister(instr->temp_vector());
   2890   DCHECK(vector.is(VectorLoadICDescriptor::VectorRegister()));
   2891   __ li(vector, instr->hydrogen()->feedback_vector());
   2892   // No need to allocate this register.
   2893   DCHECK(VectorLoadICDescriptor::SlotRegister().is(a0));
   2894   __ li(VectorLoadICDescriptor::SlotRegister(),
   2895         Operand(Smi::FromInt(instr->hydrogen()->slot())));
   2896 }
   2897 
   2898 
   2899 void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
   2900   DCHECK(ToRegister(instr->context()).is(cp));
   2901   DCHECK(ToRegister(instr->global_object())
   2902              .is(LoadDescriptor::ReceiverRegister()));
   2903   DCHECK(ToRegister(instr->result()).is(v0));
   2904 
   2905   __ li(LoadDescriptor::NameRegister(), Operand(instr->name()));
   2906   if (FLAG_vector_ics) {
   2907     EmitVectorLoadICRegisters<LLoadGlobalGeneric>(instr);
   2908   }
   2909   ContextualMode mode = instr->for_typeof() ? NOT_CONTEXTUAL : CONTEXTUAL;
   2910   Handle<Code> ic = CodeFactory::LoadIC(isolate(), mode).code();
   2911   CallCode(ic, RelocInfo::CODE_TARGET, instr);
   2912 }
   2913 
   2914 
   2915 void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
   2916   Register value = ToRegister(instr->value());
   2917   Register cell = scratch0();
   2918 
   2919   // Load the cell.
   2920   __ li(cell, Operand(instr->hydrogen()->cell().handle()));
   2921 
   2922   // If the cell we are storing to contains the hole it could have
   2923   // been deleted from the property dictionary. In that case, we need
   2924   // to update the property details in the property dictionary to mark
   2925   // it as no longer deleted.
   2926   if (instr->hydrogen()->RequiresHoleCheck()) {
   2927     // We use a temp to check the payload.
   2928     Register payload = ToRegister(instr->temp());
   2929     __ lw(payload, FieldMemOperand(cell, Cell::kValueOffset));
   2930     __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
   2931     DeoptimizeIf(eq, instr, payload, Operand(at));
   2932   }
   2933 
   2934   // Store the value.
   2935   __ sw(value, FieldMemOperand(cell, Cell::kValueOffset));
   2936   // Cells are always rescanned, so no write barrier here.
   2937 }
   2938 
   2939 
   2940 
   2941 void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
   2942   Register context = ToRegister(instr->context());
   2943   Register result = ToRegister(instr->result());
   2944 
   2945   __ lw(result, ContextOperand(context, instr->slot_index()));
   2946   if (instr->hydrogen()->RequiresHoleCheck()) {
   2947     __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
   2948 
   2949     if (instr->hydrogen()->DeoptimizesOnHole()) {
   2950       DeoptimizeIf(eq, instr, result, Operand(at));
   2951     } else {
   2952       Label is_not_hole;
   2953       __ Branch(&is_not_hole, ne, result, Operand(at));
   2954       __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
   2955       __ bind(&is_not_hole);
   2956     }
   2957   }
   2958 }
   2959 
   2960 
   2961 void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
   2962   Register context = ToRegister(instr->context());
   2963   Register value = ToRegister(instr->value());
   2964   Register scratch = scratch0();
   2965   MemOperand target = ContextOperand(context, instr->slot_index());
   2966 
   2967   Label skip_assignment;
   2968 
   2969   if (instr->hydrogen()->RequiresHoleCheck()) {
   2970     __ lw(scratch, target);
   2971     __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
   2972 
   2973     if (instr->hydrogen()->DeoptimizesOnHole()) {
   2974       DeoptimizeIf(eq, instr, scratch, Operand(at));
   2975     } else {
   2976       __ Branch(&skip_assignment, ne, scratch, Operand(at));
   2977     }
   2978   }
   2979 
   2980   __ sw(value, target);
   2981   if (instr->hydrogen()->NeedsWriteBarrier()) {
   2982     SmiCheck check_needed =
   2983         instr->hydrogen()->value()->type().IsHeapObject()
   2984             ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
   2985     __ RecordWriteContextSlot(context,
   2986                               target.offset(),
   2987                               value,
   2988                               scratch0(),
   2989                               GetRAState(),
   2990                               kSaveFPRegs,
   2991                               EMIT_REMEMBERED_SET,
   2992                               check_needed);
   2993   }
   2994 
   2995   __ bind(&skip_assignment);
   2996 }
   2997 
   2998 
   2999 void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
   3000   HObjectAccess access = instr->hydrogen()->access();
   3001   int offset = access.offset();
   3002   Register object = ToRegister(instr->object());
   3003 
   3004   if (access.IsExternalMemory()) {
   3005     Register result = ToRegister(instr->result());
   3006     MemOperand operand = MemOperand(object, offset);
   3007     __ Load(result, operand, access.representation());
   3008     return;
   3009   }
   3010 
   3011   if (instr->hydrogen()->representation().IsDouble()) {
   3012     DoubleRegister result = ToDoubleRegister(instr->result());
   3013     __ ldc1(result, FieldMemOperand(object, offset));
   3014     return;
   3015   }
   3016 
   3017   Register result = ToRegister(instr->result());
   3018   if (!access.IsInobject()) {
   3019     __ lw(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
   3020     object = result;
   3021   }
   3022   MemOperand operand = FieldMemOperand(object, offset);
   3023   __ Load(result, operand, access.representation());
   3024 }
   3025 
   3026 
   3027 void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
   3028   DCHECK(ToRegister(instr->context()).is(cp));
   3029   DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
   3030   DCHECK(ToRegister(instr->result()).is(v0));
   3031 
   3032   // Name is always in a2.
   3033   __ li(LoadDescriptor::NameRegister(), Operand(instr->name()));
   3034   if (FLAG_vector_ics) {
   3035     EmitVectorLoadICRegisters<LLoadNamedGeneric>(instr);
   3036   }
   3037   Handle<Code> ic = CodeFactory::LoadIC(isolate(), NOT_CONTEXTUAL).code();
   3038   CallCode(ic, RelocInfo::CODE_TARGET, instr);
   3039 }
   3040 
   3041 
   3042 void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
   3043   Register scratch = scratch0();
   3044   Register function = ToRegister(instr->function());
   3045   Register result = ToRegister(instr->result());
   3046 
   3047   // Get the prototype or initial map from the function.
   3048   __ lw(result,
   3049          FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
   3050 
   3051   // Check that the function has a prototype or an initial map.
   3052   __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
   3053   DeoptimizeIf(eq, instr, result, Operand(at));
   3054 
   3055   // If the function does not have an initial map, we're done.
   3056   Label done;
   3057   __ GetObjectType(result, scratch, scratch);
   3058   __ Branch(&done, ne, scratch, Operand(MAP_TYPE));
   3059 
   3060   // Get the prototype from the initial map.
   3061   __ lw(result, FieldMemOperand(result, Map::kPrototypeOffset));
   3062 
   3063   // All done.
   3064   __ bind(&done);
   3065 }
   3066 
   3067 
   3068 void LCodeGen::DoLoadRoot(LLoadRoot* instr) {
   3069   Register result = ToRegister(instr->result());
   3070   __ LoadRoot(result, instr->index());
   3071 }
   3072 
   3073 
   3074 void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
   3075   Register arguments = ToRegister(instr->arguments());
   3076   Register result = ToRegister(instr->result());
   3077   // There are two words between the frame pointer and the last argument.
   3078   // Subtracting from length accounts for one of them add one more.
   3079   if (instr->length()->IsConstantOperand()) {
   3080     int const_length = ToInteger32(LConstantOperand::cast(instr->length()));
   3081     if (instr->index()->IsConstantOperand()) {
   3082       int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
   3083       int index = (const_length - const_index) + 1;
   3084       __ lw(result, MemOperand(arguments, index * kPointerSize));
   3085     } else {
   3086       Register index = ToRegister(instr->index());
   3087       __ li(at, Operand(const_length + 1));
   3088       __ Subu(result, at, index);
   3089       __ sll(at, result, kPointerSizeLog2);
   3090       __ Addu(at, arguments, at);
   3091       __ lw(result, MemOperand(at));
   3092     }
   3093   } else if (instr->index()->IsConstantOperand()) {
   3094     Register length = ToRegister(instr->length());
   3095     int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
   3096     int loc = const_index - 1;
   3097     if (loc != 0) {
   3098       __ Subu(result, length, Operand(loc));
   3099       __ sll(at, result, kPointerSizeLog2);
   3100       __ Addu(at, arguments, at);
   3101       __ lw(result, MemOperand(at));
   3102     } else {
   3103       __ sll(at, length, kPointerSizeLog2);
   3104       __ Addu(at, arguments, at);
   3105       __ lw(result, MemOperand(at));
   3106     }
   3107   } else {
   3108     Register length = ToRegister(instr->length());
   3109     Register index = ToRegister(instr->index());
   3110     __ Subu(result, length, index);
   3111     __ Addu(result, result, 1);
   3112     __ sll(at, result, kPointerSizeLog2);
   3113     __ Addu(at, arguments, at);
   3114     __ lw(result, MemOperand(at));
   3115   }
   3116 }
   3117 
   3118 
   3119 void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
   3120   Register external_pointer = ToRegister(instr->elements());
   3121   Register key = no_reg;
   3122   ElementsKind elements_kind = instr->elements_kind();
   3123   bool key_is_constant = instr->key()->IsConstantOperand();
   3124   int constant_key = 0;
   3125   if (key_is_constant) {
   3126     constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
   3127     if (constant_key & 0xF0000000) {
   3128       Abort(kArrayIndexConstantValueTooBig);
   3129     }
   3130   } else {
   3131     key = ToRegister(instr->key());
   3132   }
   3133   int element_size_shift = ElementsKindToShiftSize(elements_kind);
   3134   int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
   3135       ? (element_size_shift - kSmiTagSize) : element_size_shift;
   3136   int base_offset = instr->base_offset();
   3137 
   3138   if (elements_kind == EXTERNAL_FLOAT32_ELEMENTS ||
   3139       elements_kind == FLOAT32_ELEMENTS ||
   3140       elements_kind == EXTERNAL_FLOAT64_ELEMENTS ||
   3141       elements_kind == FLOAT64_ELEMENTS) {
   3142     int base_offset = instr->base_offset();
   3143     FPURegister result = ToDoubleRegister(instr->result());
   3144     if (key_is_constant) {
   3145       __ Addu(scratch0(), external_pointer, constant_key << element_size_shift);
   3146     } else {
   3147       __ sll(scratch0(), key, shift_size);
   3148       __ Addu(scratch0(), scratch0(), external_pointer);
   3149     }
   3150     if (elements_kind == EXTERNAL_FLOAT32_ELEMENTS ||
   3151         elements_kind == FLOAT32_ELEMENTS) {
   3152       __ lwc1(result, MemOperand(scratch0(), base_offset));
   3153       __ cvt_d_s(result, result);
   3154     } else  {  // i.e. elements_kind == EXTERNAL_DOUBLE_ELEMENTS
   3155       __ ldc1(result, MemOperand(scratch0(), base_offset));
   3156     }
   3157   } else {
   3158     Register result = ToRegister(instr->result());
   3159     MemOperand mem_operand = PrepareKeyedOperand(
   3160         key, external_pointer, key_is_constant, constant_key,
   3161         element_size_shift, shift_size, base_offset);
   3162     switch (elements_kind) {
   3163       case EXTERNAL_INT8_ELEMENTS:
   3164       case INT8_ELEMENTS:
   3165         __ lb(result, mem_operand);
   3166         break;
   3167       case EXTERNAL_UINT8_CLAMPED_ELEMENTS:
   3168       case EXTERNAL_UINT8_ELEMENTS:
   3169       case UINT8_ELEMENTS:
   3170       case UINT8_CLAMPED_ELEMENTS:
   3171         __ lbu(result, mem_operand);
   3172         break;
   3173       case EXTERNAL_INT16_ELEMENTS:
   3174       case INT16_ELEMENTS:
   3175         __ lh(result, mem_operand);
   3176         break;
   3177       case EXTERNAL_UINT16_ELEMENTS:
   3178       case UINT16_ELEMENTS:
   3179         __ lhu(result, mem_operand);
   3180         break;
   3181       case EXTERNAL_INT32_ELEMENTS:
   3182       case INT32_ELEMENTS:
   3183         __ lw(result, mem_operand);
   3184         break;
   3185       case EXTERNAL_UINT32_ELEMENTS:
   3186       case UINT32_ELEMENTS:
   3187         __ lw(result, mem_operand);
   3188         if (!instr->hydrogen()->CheckFlag(HInstruction::kUint32)) {
   3189           DeoptimizeIf(Ugreater_equal, instr, result, Operand(0x80000000));
   3190         }
   3191         break;
   3192       case FLOAT32_ELEMENTS:
   3193       case FLOAT64_ELEMENTS:
   3194       case EXTERNAL_FLOAT32_ELEMENTS:
   3195       case EXTERNAL_FLOAT64_ELEMENTS:
   3196       case FAST_DOUBLE_ELEMENTS:
   3197       case FAST_ELEMENTS:
   3198       case FAST_SMI_ELEMENTS:
   3199       case FAST_HOLEY_DOUBLE_ELEMENTS:
   3200       case FAST_HOLEY_ELEMENTS:
   3201       case FAST_HOLEY_SMI_ELEMENTS:
   3202       case DICTIONARY_ELEMENTS:
   3203       case SLOPPY_ARGUMENTS_ELEMENTS:
   3204         UNREACHABLE();
   3205         break;
   3206     }
   3207   }
   3208 }
   3209 
   3210 
   3211 void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
   3212   Register elements = ToRegister(instr->elements());
   3213   bool key_is_constant = instr->key()->IsConstantOperand();
   3214   Register key = no_reg;
   3215   DoubleRegister result = ToDoubleRegister(instr->result());
   3216   Register scratch = scratch0();
   3217 
   3218   int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
   3219 
   3220   int base_offset = instr->base_offset();
   3221   if (key_is_constant) {
   3222     int constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
   3223     if (constant_key & 0xF0000000) {
   3224       Abort(kArrayIndexConstantValueTooBig);
   3225     }
   3226     base_offset += constant_key * kDoubleSize;
   3227   }
   3228   __ Addu(scratch, elements, Operand(base_offset));
   3229 
   3230   if (!key_is_constant) {
   3231     key = ToRegister(instr->key());
   3232     int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
   3233         ? (element_size_shift - kSmiTagSize) : element_size_shift;
   3234     __ sll(at, key, shift_size);
   3235     __ Addu(scratch, scratch, at);
   3236   }
   3237 
   3238   __ ldc1(result, MemOperand(scratch));
   3239 
   3240   if (instr->hydrogen()->RequiresHoleCheck()) {
   3241     __ lw(scratch, MemOperand(scratch, kHoleNanUpper32Offset));
   3242     DeoptimizeIf(eq, instr, scratch, Operand(kHoleNanUpper32));
   3243   }
   3244 }
   3245 
   3246 
   3247 void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
   3248   Register elements = ToRegister(instr->elements());
   3249   Register result = ToRegister(instr->result());
   3250   Register scratch = scratch0();
   3251   Register store_base = scratch;
   3252   int offset = instr->base_offset();
   3253 
   3254   if (instr->key()->IsConstantOperand()) {
   3255     LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
   3256     offset += ToInteger32(const_operand) * kPointerSize;
   3257     store_base = elements;
   3258   } else {
   3259     Register key = ToRegister(instr->key());
   3260     // Even though the HLoadKeyed instruction forces the input
   3261     // representation for the key to be an integer, the input gets replaced
   3262     // during bound check elimination with the index argument to the bounds
   3263     // check, which can be tagged, so that case must be handled here, too.
   3264     if (instr->hydrogen()->key()->representation().IsSmi()) {
   3265       __ sll(scratch, key, kPointerSizeLog2 - kSmiTagSize);
   3266       __ addu(scratch, elements, scratch);
   3267     } else {
   3268       __ sll(scratch, key, kPointerSizeLog2);
   3269       __ addu(scratch, elements, scratch);
   3270     }
   3271   }
   3272   __ lw(result, MemOperand(store_base, offset));
   3273 
   3274   // Check for the hole value.
   3275   if (instr->hydrogen()->RequiresHoleCheck()) {
   3276     if (IsFastSmiElementsKind(instr->hydrogen()->elements_kind())) {
   3277       __ SmiTst(result, scratch);
   3278       DeoptimizeIf(ne, instr, scratch, Operand(zero_reg));
   3279     } else {
   3280       __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
   3281       DeoptimizeIf(eq, instr, result, Operand(scratch));
   3282     }
   3283   }
   3284 }
   3285 
   3286 
   3287 void LCodeGen::DoLoadKeyed(LLoadKeyed* instr) {
   3288   if (instr->is_typed_elements()) {
   3289     DoLoadKeyedExternalArray(instr);
   3290   } else if (instr->hydrogen()->representation().IsDouble()) {
   3291     DoLoadKeyedFixedDoubleArray(instr);
   3292   } else {
   3293     DoLoadKeyedFixedArray(instr);
   3294   }
   3295 }
   3296 
   3297 
   3298 MemOperand LCodeGen::PrepareKeyedOperand(Register key,
   3299                                          Register base,
   3300                                          bool key_is_constant,
   3301                                          int constant_key,
   3302                                          int element_size,
   3303                                          int shift_size,
   3304                                          int base_offset) {
   3305   if (key_is_constant) {
   3306     return MemOperand(base, (constant_key << element_size) + base_offset);
   3307   }
   3308 
   3309   if (base_offset == 0) {
   3310     if (shift_size >= 0) {
   3311       __ sll(scratch0(), key, shift_size);
   3312       __ Addu(scratch0(), base, scratch0());
   3313       return MemOperand(scratch0());
   3314     } else {
   3315       DCHECK_EQ(-1, shift_size);
   3316       __ srl(scratch0(), key, 1);
   3317       __ Addu(scratch0(), base, scratch0());
   3318       return MemOperand(scratch0());
   3319     }
   3320   }
   3321 
   3322   if (shift_size >= 0) {
   3323     __ sll(scratch0(), key, shift_size);
   3324     __ Addu(scratch0(), base, scratch0());
   3325     return MemOperand(scratch0(), base_offset);
   3326   } else {
   3327     DCHECK_EQ(-1, shift_size);
   3328     __ sra(scratch0(), key, 1);
   3329     __ Addu(scratch0(), base, scratch0());
   3330     return MemOperand(scratch0(), base_offset);
   3331   }
   3332 }
   3333 
   3334 
   3335 void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
   3336   DCHECK(ToRegister(instr->context()).is(cp));
   3337   DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
   3338   DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
   3339 
   3340   if (FLAG_vector_ics) {
   3341     EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
   3342   }
   3343 
   3344   Handle<Code> ic = CodeFactory::KeyedLoadIC(isolate()).code();
   3345   CallCode(ic, RelocInfo::CODE_TARGET, instr);
   3346 }
   3347 
   3348 
   3349 void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
   3350   Register scratch = scratch0();
   3351   Register temp = scratch1();
   3352   Register result = ToRegister(instr->result());
   3353 
   3354   if (instr->hydrogen()->from_inlined()) {
   3355     __ Subu(result, sp, 2 * kPointerSize);
   3356   } else {
   3357     // Check if the calling frame is an arguments adaptor frame.
   3358     Label done, adapted;
   3359     __ lw(scratch, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   3360     __ lw(result, MemOperand(scratch, StandardFrameConstants::kContextOffset));
   3361     __ Xor(temp, result, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
   3362 
   3363     // Result is the frame pointer for the frame if not adapted and for the real
   3364     // frame below the adaptor frame if adapted.
   3365     __ Movn(result, fp, temp);  // Move only if temp is not equal to zero (ne).
   3366     __ Movz(result, scratch, temp);  // Move only if temp is equal to zero (eq).
   3367   }
   3368 }
   3369 
   3370 
   3371 void LCodeGen::DoArgumentsLength(LArgumentsLength* instr) {
   3372   Register elem = ToRegister(instr->elements());
   3373   Register result = ToRegister(instr->result());
   3374 
   3375   Label done;
   3376 
   3377   // If no arguments adaptor frame the number of arguments is fixed.
   3378   __ Addu(result, zero_reg, Operand(scope()->num_parameters()));
   3379   __ Branch(&done, eq, fp, Operand(elem));
   3380 
   3381   // Arguments adaptor frame present. Get argument length from there.
   3382   __ lw(result, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   3383   __ lw(result,
   3384         MemOperand(result, ArgumentsAdaptorFrameConstants::kLengthOffset));
   3385   __ SmiUntag(result);
   3386 
   3387   // Argument length is in result register.
   3388   __ bind(&done);
   3389 }
   3390 
   3391 
   3392 void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
   3393   Register receiver = ToRegister(instr->receiver());
   3394   Register function = ToRegister(instr->function());
   3395   Register result = ToRegister(instr->result());
   3396   Register scratch = scratch0();
   3397 
   3398   // If the receiver is null or undefined, we have to pass the global
   3399   // object as a receiver to normal functions. Values have to be
   3400   // passed unchanged to builtins and strict-mode functions.
   3401   Label global_object, result_in_receiver;
   3402 
   3403   if (!instr->hydrogen()->known_function()) {
   3404     // Do not transform the receiver to object for strict mode
   3405     // functions.
   3406     __ lw(scratch,
   3407            FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
   3408     __ lw(scratch,
   3409            FieldMemOperand(scratch, SharedFunctionInfo::kCompilerHintsOffset));
   3410 
   3411     // Do not transform the receiver to object for builtins.
   3412     int32_t strict_mode_function_mask =
   3413         1 <<  (SharedFunctionInfo::kStrictModeFunction + kSmiTagSize);
   3414     int32_t native_mask = 1 << (SharedFunctionInfo::kNative + kSmiTagSize);
   3415     __ And(scratch, scratch, Operand(strict_mode_function_mask | native_mask));
   3416     __ Branch(&result_in_receiver, ne, scratch, Operand(zero_reg));
   3417   }
   3418 
   3419   // Normal function. Replace undefined or null with global receiver.
   3420   __ LoadRoot(scratch, Heap::kNullValueRootIndex);
   3421   __ Branch(&global_object, eq, receiver, Operand(scratch));
   3422   __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   3423   __ Branch(&global_object, eq, receiver, Operand(scratch));
   3424 
   3425   // Deoptimize if the receiver is not a JS object.
   3426   __ SmiTst(receiver, scratch);
   3427   DeoptimizeIf(eq, instr, scratch, Operand(zero_reg));
   3428 
   3429   __ GetObjectType(receiver, scratch, scratch);
   3430   DeoptimizeIf(lt, instr, scratch, Operand(FIRST_SPEC_OBJECT_TYPE));
   3431 
   3432   __ Branch(&result_in_receiver);
   3433   __ bind(&global_object);
   3434   __ lw(result, FieldMemOperand(function, JSFunction::kContextOffset));
   3435   __ lw(result,
   3436         ContextOperand(result, Context::GLOBAL_OBJECT_INDEX));
   3437   __ lw(result,
   3438         FieldMemOperand(result, GlobalObject::kGlobalProxyOffset));
   3439 
   3440   if (result.is(receiver)) {
   3441     __ bind(&result_in_receiver);
   3442   } else {
   3443     Label result_ok;
   3444     __ Branch(&result_ok);
   3445     __ bind(&result_in_receiver);
   3446     __ mov(result, receiver);
   3447     __ bind(&result_ok);
   3448   }
   3449 }
   3450 
   3451 
   3452 void LCodeGen::DoApplyArguments(LApplyArguments* instr) {
   3453   Register receiver = ToRegister(instr->receiver());
   3454   Register function = ToRegister(instr->function());
   3455   Register length = ToRegister(instr->length());
   3456   Register elements = ToRegister(instr->elements());
   3457   Register scratch = scratch0();
   3458   DCHECK(receiver.is(a0));  // Used for parameter count.
   3459   DCHECK(function.is(a1));  // Required by InvokeFunction.
   3460   DCHECK(ToRegister(instr->result()).is(v0));
   3461 
   3462   // Copy the arguments to this function possibly from the
   3463   // adaptor frame below it.
   3464   const uint32_t kArgumentsLimit = 1 * KB;
   3465   DeoptimizeIf(hi, instr, length, Operand(kArgumentsLimit));
   3466 
   3467   // Push the receiver and use the register to keep the original
   3468   // number of arguments.
   3469   __ push(receiver);
   3470   __ Move(receiver, length);
   3471   // The arguments are at a one pointer size offset from elements.
   3472   __ Addu(elements, elements, Operand(1 * kPointerSize));
   3473 
   3474   // Loop through the arguments pushing them onto the execution
   3475   // stack.
   3476   Label invoke, loop;
   3477   // length is a small non-negative integer, due to the test above.
   3478   __ Branch(USE_DELAY_SLOT, &invoke, eq, length, Operand(zero_reg));
   3479   __ sll(scratch, length, 2);
   3480   __ bind(&loop);
   3481   __ Addu(scratch, elements, scratch);
   3482   __ lw(scratch, MemOperand(scratch));
   3483   __ push(scratch);
   3484   __ Subu(length, length, Operand(1));
   3485   __ Branch(USE_DELAY_SLOT, &loop, ne, length, Operand(zero_reg));
   3486   __ sll(scratch, length, 2);
   3487 
   3488   __ bind(&invoke);
   3489   DCHECK(instr->HasPointerMap());
   3490   LPointerMap* pointers = instr->pointer_map();
   3491   SafepointGenerator safepoint_generator(
   3492       this, pointers, Safepoint::kLazyDeopt);
   3493   // The number of arguments is stored in receiver which is a0, as expected
   3494   // by InvokeFunction.
   3495   ParameterCount actual(receiver);
   3496   __ InvokeFunction(function, actual, CALL_FUNCTION, safepoint_generator);
   3497 }
   3498 
   3499 
   3500 void LCodeGen::DoPushArgument(LPushArgument* instr) {
   3501   LOperand* argument = instr->value();
   3502   if (argument->IsDoubleRegister() || argument->IsDoubleStackSlot()) {
   3503     Abort(kDoPushArgumentNotImplementedForDoubleType);
   3504   } else {
   3505     Register argument_reg = EmitLoadRegister(argument, at);
   3506     __ push(argument_reg);
   3507   }
   3508 }
   3509 
   3510 
   3511 void LCodeGen::DoDrop(LDrop* instr) {
   3512   __ Drop(instr->count());
   3513 }
   3514 
   3515 
   3516 void LCodeGen::DoThisFunction(LThisFunction* instr) {
   3517   Register result = ToRegister(instr->result());
   3518   __ lw(result, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   3519 }
   3520 
   3521 
   3522 void LCodeGen::DoContext(LContext* instr) {
   3523   // If there is a non-return use, the context must be moved to a register.
   3524   Register result = ToRegister(instr->result());
   3525   if (info()->IsOptimizing()) {
   3526     __ lw(result, MemOperand(fp, StandardFrameConstants::kContextOffset));
   3527   } else {
   3528     // If there is no frame, the context must be in cp.
   3529     DCHECK(result.is(cp));
   3530   }
   3531 }
   3532 
   3533 
   3534 void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
   3535   DCHECK(ToRegister(instr->context()).is(cp));
   3536   __ li(scratch0(), instr->hydrogen()->pairs());
   3537   __ li(scratch1(), Operand(Smi::FromInt(instr->hydrogen()->flags())));
   3538   // The context is the first argument.
   3539   __ Push(cp, scratch0(), scratch1());
   3540   CallRuntime(Runtime::kDeclareGlobals, 3, instr);
   3541 }
   3542 
   3543 
   3544 void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
   3545                                  int formal_parameter_count,
   3546                                  int arity,
   3547                                  LInstruction* instr,
   3548                                  A1State a1_state) {
   3549   bool dont_adapt_arguments =
   3550       formal_parameter_count == SharedFunctionInfo::kDontAdaptArgumentsSentinel;
   3551   bool can_invoke_directly =
   3552       dont_adapt_arguments || formal_parameter_count == arity;
   3553 
   3554   LPointerMap* pointers = instr->pointer_map();
   3555 
   3556   if (can_invoke_directly) {
   3557     if (a1_state == A1_UNINITIALIZED) {
   3558       __ li(a1, function);
   3559     }
   3560 
   3561     // Change context.
   3562     __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
   3563 
   3564     // Set r0 to arguments count if adaption is not needed. Assumes that r0
   3565     // is available to write to at this point.
   3566     if (dont_adapt_arguments) {
   3567       __ li(a0, Operand(arity));
   3568     }
   3569 
   3570     // Invoke function.
   3571     __ lw(at, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
   3572     __ Call(at);
   3573 
   3574     // Set up deoptimization.
   3575     RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
   3576   } else {
   3577     SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
   3578     ParameterCount count(arity);
   3579     ParameterCount expected(formal_parameter_count);
   3580     __ InvokeFunction(function, expected, count, CALL_FUNCTION, generator);
   3581   }
   3582 }
   3583 
   3584 
   3585 void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr) {
   3586   DCHECK(instr->context() != NULL);
   3587   DCHECK(ToRegister(instr->context()).is(cp));
   3588   Register input = ToRegister(instr->value());
   3589   Register result = ToRegister(instr->result());
   3590   Register scratch = scratch0();
   3591 
   3592   // Deoptimize if not a heap number.
   3593   __ lw(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
   3594   __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
   3595   DeoptimizeIf(ne, instr, scratch, Operand(at));
   3596 
   3597   Label done;
   3598   Register exponent = scratch0();
   3599   scratch = no_reg;
   3600   __ lw(exponent, FieldMemOperand(input, HeapNumber::kExponentOffset));
   3601   // Check the sign of the argument. If the argument is positive, just
   3602   // return it.
   3603   __ Move(result, input);
   3604   __ And(at, exponent, Operand(HeapNumber::kSignMask));
   3605   __ Branch(&done, eq, at, Operand(zero_reg));
   3606 
   3607   // Input is negative. Reverse its sign.
   3608   // Preserve the value of all registers.
   3609   {
   3610     PushSafepointRegistersScope scope(this);
   3611 
   3612     // Registers were saved at the safepoint, so we can use
   3613     // many scratch registers.
   3614     Register tmp1 = input.is(a1) ? a0 : a1;
   3615     Register tmp2 = input.is(a2) ? a0 : a2;
   3616     Register tmp3 = input.is(a3) ? a0 : a3;
   3617     Register tmp4 = input.is(t0) ? a0 : t0;
   3618 
   3619     // exponent: floating point exponent value.
   3620 
   3621     Label allocated, slow;
   3622     __ LoadRoot(tmp4, Heap::kHeapNumberMapRootIndex);
   3623     __ AllocateHeapNumber(tmp1, tmp2, tmp3, tmp4, &slow);
   3624     __ Branch(&allocated);
   3625 
   3626     // Slow case: Call the runtime system to do the number allocation.
   3627     __ bind(&slow);
   3628 
   3629     CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr,
   3630                             instr->context());
   3631     // Set the pointer to the new heap number in tmp.
   3632     if (!tmp1.is(v0))
   3633       __ mov(tmp1, v0);
   3634     // Restore input_reg after call to runtime.
   3635     __ LoadFromSafepointRegisterSlot(input, input);
   3636     __ lw(exponent, FieldMemOperand(input, HeapNumber::kExponentOffset));
   3637 
   3638     __ bind(&allocated);
   3639     // exponent: floating point exponent value.
   3640     // tmp1: allocated heap number.
   3641     __ And(exponent, exponent, Operand(~HeapNumber::kSignMask));
   3642     __ sw(exponent, FieldMemOperand(tmp1, HeapNumber::kExponentOffset));
   3643     __ lw(tmp2, FieldMemOperand(input, HeapNumber::kMantissaOffset));
   3644     __ sw(tmp2, FieldMemOperand(tmp1, HeapNumber::kMantissaOffset));
   3645 
   3646     __ StoreToSafepointRegisterSlot(tmp1, result);
   3647   }
   3648 
   3649   __ bind(&done);
   3650 }
   3651 
   3652 
   3653 void LCodeGen::EmitIntegerMathAbs(LMathAbs* instr) {
   3654   Register input = ToRegister(instr->value());
   3655   Register result = ToRegister(instr->result());
   3656   Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
   3657   Label done;
   3658   __ Branch(USE_DELAY_SLOT, &done, ge, input, Operand(zero_reg));
   3659   __ mov(result, input);
   3660   __ subu(result, zero_reg, input);
   3661   // Overflow if result is still negative, i.e. 0x80000000.
   3662   DeoptimizeIf(lt, instr, result, Operand(zero_reg));
   3663   __ bind(&done);
   3664 }
   3665 
   3666 
   3667 void LCodeGen::DoMathAbs(LMathAbs* instr) {
   3668   // Class for deferred case.
   3669   class DeferredMathAbsTaggedHeapNumber FINAL : public LDeferredCode {
   3670    public:
   3671     DeferredMathAbsTaggedHeapNumber(LCodeGen* codegen, LMathAbs* instr)
   3672         : LDeferredCode(codegen), instr_(instr) { }
   3673     virtual void Generate() OVERRIDE {
   3674       codegen()->DoDeferredMathAbsTaggedHeapNumber(instr_);
   3675     }
   3676     virtual LInstruction* instr() OVERRIDE { return instr_; }
   3677    private:
   3678     LMathAbs* instr_;
   3679   };
   3680 
   3681   Representation r = instr->hydrogen()->value()->representation();
   3682   if (r.IsDouble()) {
   3683     FPURegister input = ToDoubleRegister(instr->value());
   3684     FPURegister result = ToDoubleRegister(instr->result());
   3685     __ abs_d(result, input);
   3686   } else if (r.IsSmiOrInteger32()) {
   3687     EmitIntegerMathAbs(instr);
   3688   } else {
   3689     // Representation is tagged.
   3690     DeferredMathAbsTaggedHeapNumber* deferred =
   3691         new(zone()) DeferredMathAbsTaggedHeapNumber(this, instr);
   3692     Register input = ToRegister(instr->value());
   3693     // Smi check.
   3694     __ JumpIfNotSmi(input, deferred->entry());
   3695     // If smi, handle it directly.
   3696     EmitIntegerMathAbs(instr);
   3697     __ bind(deferred->exit());
   3698   }
   3699 }
   3700 
   3701 
   3702 void LCodeGen::DoMathFloor(LMathFloor* instr) {
   3703   DoubleRegister input = ToDoubleRegister(instr->value());
   3704   Register result = ToRegister(instr->result());
   3705   Register scratch1 = scratch0();
   3706   Register except_flag = ToRegister(instr->temp());
   3707 
   3708   __ EmitFPUTruncate(kRoundToMinusInf,
   3709                      result,
   3710                      input,
   3711                      scratch1,
   3712                      double_scratch0(),
   3713                      except_flag);
   3714 
   3715   // Deopt if the operation did not succeed.
   3716   DeoptimizeIf(ne, instr, except_flag, Operand(zero_reg));
   3717 
   3718   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
   3719     // Test for -0.
   3720     Label done;
   3721     __ Branch(&done, ne, result, Operand(zero_reg));
   3722     __ Mfhc1(scratch1, input);
   3723     __ And(scratch1, scratch1, Operand(HeapNumber::kSignMask));
   3724     DeoptimizeIf(ne, instr, scratch1, Operand(zero_reg));
   3725     __ bind(&done);
   3726   }
   3727 }
   3728 
   3729 
   3730 void LCodeGen::DoMathRound(LMathRound* instr) {
   3731   DoubleRegister input = ToDoubleRegister(instr->value());
   3732   Register result = ToRegister(instr->result());
   3733   DoubleRegister double_scratch1 = ToDoubleRegister(instr->temp());
   3734   Register scratch = scratch0();
   3735   Label done, check_sign_on_zero;
   3736 
   3737   // Extract exponent bits.
   3738   __ Mfhc1(result, input);
   3739   __ Ext(scratch,
   3740          result,
   3741          HeapNumber::kExponentShift,
   3742          HeapNumber::kExponentBits);
   3743 
   3744   // If the number is in ]-0.5, +0.5[, the result is +/- 0.
   3745   Label skip1;
   3746   __ Branch(&skip1, gt, scratch, Operand(HeapNumber::kExponentBias - 2));
   3747   __ mov(result, zero_reg);
   3748   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
   3749     __ Branch(&check_sign_on_zero);
   3750   } else {
   3751     __ Branch(&done);
   3752   }
   3753   __ bind(&skip1);
   3754 
   3755   // The following conversion will not work with numbers
   3756   // outside of ]-2^32, 2^32[.
   3757   DeoptimizeIf(ge, instr, scratch, Operand(HeapNumber::kExponentBias + 32));
   3758 
   3759   // Save the original sign for later comparison.
   3760   __ And(scratch, result, Operand(HeapNumber::kSignMask));
   3761 
   3762   __ Move(double_scratch0(), 0.5);
   3763   __ add_d(double_scratch0(), input, double_scratch0());
   3764 
   3765   // Check sign of the result: if the sign changed, the input
   3766   // value was in ]0.5, 0[ and the result should be -0.
   3767   __ Mfhc1(result, double_scratch0());
   3768   __ Xor(result, result, Operand(scratch));
   3769   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
   3770     // ARM uses 'mi' here, which is 'lt'
   3771     DeoptimizeIf(lt, instr, result, Operand(zero_reg));
   3772   } else {
   3773     Label skip2;
   3774     // ARM uses 'mi' here, which is 'lt'
   3775     // Negating it results in 'ge'
   3776     __ Branch(&skip2, ge, result, Operand(zero_reg));
   3777     __ mov(result, zero_reg);
   3778     __ Branch(&done);
   3779     __ bind(&skip2);
   3780   }
   3781 
   3782   Register except_flag = scratch;
   3783   __ EmitFPUTruncate(kRoundToMinusInf,
   3784                      result,
   3785                      double_scratch0(),
   3786                      at,
   3787                      double_scratch1,
   3788                      except_flag);
   3789 
   3790   DeoptimizeIf(ne, instr, except_flag, Operand(zero_reg));
   3791 
   3792   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
   3793     // Test for -0.
   3794     __ Branch(&done, ne, result, Operand(zero_reg));
   3795     __ bind(&check_sign_on_zero);
   3796     __ Mfhc1(scratch, input);
   3797     __ And(scratch, scratch, Operand(HeapNumber::kSignMask));
   3798     DeoptimizeIf(ne, instr, scratch, Operand(zero_reg));
   3799   }
   3800   __ bind(&done);
   3801 }
   3802 
   3803 
   3804 void LCodeGen::DoMathFround(LMathFround* instr) {
   3805   DoubleRegister input = ToDoubleRegister(instr->value());
   3806   DoubleRegister result = ToDoubleRegister(instr->result());
   3807   __ cvt_s_d(result.low(), input);
   3808   __ cvt_d_s(result, result.low());
   3809 }
   3810 
   3811 
   3812 void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
   3813   DoubleRegister input = ToDoubleRegister(instr->value());
   3814   DoubleRegister result = ToDoubleRegister(instr->result());
   3815   __ sqrt_d(result, input);
   3816 }
   3817 
   3818 
   3819 void LCodeGen::DoMathPowHalf(LMathPowHalf* instr) {
   3820   DoubleRegister input = ToDoubleRegister(instr->value());
   3821   DoubleRegister result = ToDoubleRegister(instr->result());
   3822   DoubleRegister temp = ToDoubleRegister(instr->temp());
   3823 
   3824   DCHECK(!input.is(result));
   3825 
   3826   // Note that according to ECMA-262 15.8.2.13:
   3827   // Math.pow(-Infinity, 0.5) == Infinity
   3828   // Math.sqrt(-Infinity) == NaN
   3829   Label done;
   3830   __ Move(temp, -V8_INFINITY);
   3831   __ BranchF(USE_DELAY_SLOT, &done, NULL, eq, temp, input);
   3832   // Set up Infinity in the delay slot.
   3833   // result is overwritten if the branch is not taken.
   3834   __ neg_d(result, temp);
   3835 
   3836   // Add +0 to convert -0 to +0.
   3837   __ add_d(result, input, kDoubleRegZero);
   3838   __ sqrt_d(result, result);
   3839   __ bind(&done);
   3840 }
   3841 
   3842 
   3843 void LCodeGen::DoPower(LPower* instr) {
   3844   Representation exponent_type = instr->hydrogen()->right()->representation();
   3845   // Having marked this as a call, we can use any registers.
   3846   // Just make sure that the input/output registers are the expected ones.
   3847   Register tagged_exponent = MathPowTaggedDescriptor::exponent();
   3848   DCHECK(!instr->right()->IsDoubleRegister() ||
   3849          ToDoubleRegister(instr->right()).is(f4));
   3850   DCHECK(!instr->right()->IsRegister() ||
   3851          ToRegister(instr->right()).is(tagged_exponent));
   3852   DCHECK(ToDoubleRegister(instr->left()).is(f2));
   3853   DCHECK(ToDoubleRegister(instr->result()).is(f0));
   3854 
   3855   if (exponent_type.IsSmi()) {
   3856     MathPowStub stub(isolate(), MathPowStub::TAGGED);
   3857     __ CallStub(&stub);
   3858   } else if (exponent_type.IsTagged()) {
   3859     Label no_deopt;
   3860     __ JumpIfSmi(tagged_exponent, &no_deopt);
   3861     DCHECK(!t3.is(tagged_exponent));
   3862     __ lw(t3, FieldMemOperand(tagged_exponent, HeapObject::kMapOffset));
   3863     __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
   3864     DeoptimizeIf(ne, instr, t3, Operand(at));
   3865     __ bind(&no_deopt);
   3866     MathPowStub stub(isolate(), MathPowStub::TAGGED);
   3867     __ CallStub(&stub);
   3868   } else if (exponent_type.IsInteger32()) {
   3869     MathPowStub stub(isolate(), MathPowStub::INTEGER);
   3870     __ CallStub(&stub);
   3871   } else {
   3872     DCHECK(exponent_type.IsDouble());
   3873     MathPowStub stub(isolate(), MathPowStub::DOUBLE);
   3874     __ CallStub(&stub);
   3875   }
   3876 }
   3877 
   3878 
   3879 void LCodeGen::DoMathExp(LMathExp* instr) {
   3880   DoubleRegister input = ToDoubleRegister(instr->value());
   3881   DoubleRegister result = ToDoubleRegister(instr->result());
   3882   DoubleRegister double_scratch1 = ToDoubleRegister(instr->double_temp());
   3883   DoubleRegister double_scratch2 = double_scratch0();
   3884   Register temp1 = ToRegister(instr->temp1());
   3885   Register temp2 = ToRegister(instr->temp2());
   3886 
   3887   MathExpGenerator::EmitMathExp(
   3888       masm(), input, result, double_scratch1, double_scratch2,
   3889       temp1, temp2, scratch0());
   3890 }
   3891 
   3892 
   3893 void LCodeGen::DoMathLog(LMathLog* instr) {
   3894   __ PrepareCallCFunction(0, 1, scratch0());
   3895   __ MovToFloatParameter(ToDoubleRegister(instr->value()));
   3896   __ CallCFunction(ExternalReference::math_log_double_function(isolate()),
   3897                    0, 1);
   3898   __ MovFromFloatResult(ToDoubleRegister(instr->result()));
   3899 }
   3900 
   3901 
   3902 void LCodeGen::DoMathClz32(LMathClz32* instr) {
   3903   Register input = ToRegister(instr->value());
   3904   Register result = ToRegister(instr->result());
   3905   __ Clz(result, input);
   3906 }
   3907 
   3908 
   3909 void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
   3910   DCHECK(ToRegister(instr->context()).is(cp));
   3911   DCHECK(ToRegister(instr->function()).is(a1));
   3912   DCHECK(instr->HasPointerMap());
   3913 
   3914   Handle<JSFunction> known_function = instr->hydrogen()->known_function();
   3915   if (known_function.is_null()) {
   3916     LPointerMap* pointers = instr->pointer_map();
   3917     SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
   3918     ParameterCount count(instr->arity());
   3919     __ InvokeFunction(a1, count, CALL_FUNCTION, generator);
   3920   } else {
   3921     CallKnownFunction(known_function,
   3922                       instr->hydrogen()->formal_parameter_count(),
   3923                       instr->arity(),
   3924                       instr,
   3925                       A1_CONTAINS_TARGET);
   3926   }
   3927 }
   3928 
   3929 
   3930 void LCodeGen::DoTailCallThroughMegamorphicCache(
   3931     LTailCallThroughMegamorphicCache* instr) {
   3932   Register receiver = ToRegister(instr->receiver());
   3933   Register name = ToRegister(instr->name());
   3934   DCHECK(receiver.is(LoadDescriptor::ReceiverRegister()));
   3935   DCHECK(name.is(LoadDescriptor::NameRegister()));
   3936   DCHECK(receiver.is(a1));
   3937   DCHECK(name.is(a2));
   3938 
   3939   Register scratch = a3;
   3940   Register extra = t0;
   3941   Register extra2 = t1;
   3942   Register extra3 = t2;
   3943 
   3944   // Important for the tail-call.
   3945   bool must_teardown_frame = NeedsEagerFrame();
   3946 
   3947   // The probe will tail call to a handler if found.
   3948   isolate()->stub_cache()->GenerateProbe(masm(), instr->hydrogen()->flags(),
   3949                                          must_teardown_frame, receiver, name,
   3950                                          scratch, extra, extra2, extra3);
   3951 
   3952   // Tail call to miss if we ended up here.
   3953   if (must_teardown_frame) __ LeaveFrame(StackFrame::INTERNAL);
   3954   LoadIC::GenerateMiss(masm());
   3955 }
   3956 
   3957 
   3958 void LCodeGen::DoCallWithDescriptor(LCallWithDescriptor* instr) {
   3959   DCHECK(ToRegister(instr->result()).is(v0));
   3960 
   3961   LPointerMap* pointers = instr->pointer_map();
   3962   SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
   3963 
   3964   if (instr->target()->IsConstantOperand()) {
   3965     LConstantOperand* target = LConstantOperand::cast(instr->target());
   3966     Handle<Code> code = Handle<Code>::cast(ToHandle(target));
   3967     generator.BeforeCall(__ CallSize(code, RelocInfo::CODE_TARGET));
   3968     __ Call(code, RelocInfo::CODE_TARGET);
   3969   } else {
   3970     DCHECK(instr->target()->IsRegister());
   3971     Register target = ToRegister(instr->target());
   3972     generator.BeforeCall(__ CallSize(target));
   3973     __ Addu(target, target, Operand(Code::kHeaderSize - kHeapObjectTag));
   3974     __ Call(target);
   3975   }
   3976   generator.AfterCall();
   3977 }
   3978 
   3979 
   3980 void LCodeGen::DoCallJSFunction(LCallJSFunction* instr) {
   3981   DCHECK(ToRegister(instr->function()).is(a1));
   3982   DCHECK(ToRegister(instr->result()).is(v0));
   3983 
   3984   if (instr->hydrogen()->pass_argument_count()) {
   3985     __ li(a0, Operand(instr->arity()));
   3986   }
   3987 
   3988   // Change context.
   3989   __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
   3990 
   3991   // Load the code entry address
   3992   __ lw(at, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
   3993   __ Call(at);
   3994 
   3995   RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
   3996 }
   3997 
   3998 
   3999 void LCodeGen::DoCallFunction(LCallFunction* instr) {
   4000   DCHECK(ToRegister(instr->context()).is(cp));
   4001   DCHECK(ToRegister(instr->function()).is(a1));
   4002   DCHECK(ToRegister(instr->result()).is(v0));
   4003 
   4004   int arity = instr->arity();
   4005   CallFunctionStub stub(isolate(), arity, instr->hydrogen()->function_flags());
   4006   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   4007 }
   4008 
   4009 
   4010 void LCodeGen::DoCallNew(LCallNew* instr) {
   4011   DCHECK(ToRegister(instr->context()).is(cp));
   4012   DCHECK(ToRegister(instr->constructor()).is(a1));
   4013   DCHECK(ToRegister(instr->result()).is(v0));
   4014 
   4015   __ li(a0, Operand(instr->arity()));
   4016   // No cell in a2 for construct type feedback in optimized code
   4017   __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
   4018   CallConstructStub stub(isolate(), NO_CALL_CONSTRUCTOR_FLAGS);
   4019   CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
   4020 }
   4021 
   4022 
   4023 void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
   4024   DCHECK(ToRegister(instr->context()).is(cp));
   4025   DCHECK(ToRegister(instr->constructor()).is(a1));
   4026   DCHECK(ToRegister(instr->result()).is(v0));
   4027 
   4028   __ li(a0, Operand(instr->arity()));
   4029   __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
   4030   ElementsKind kind = instr->hydrogen()->elements_kind();
   4031   AllocationSiteOverrideMode override_mode =
   4032       (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE)
   4033           ? DISABLE_ALLOCATION_SITES
   4034           : DONT_OVERRIDE;
   4035 
   4036   if (instr->arity() == 0) {
   4037     ArrayNoArgumentConstructorStub stub(isolate(), kind, override_mode);
   4038     CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
   4039   } else if (instr->arity() == 1) {
   4040     Label done;
   4041     if (IsFastPackedElementsKind(kind)) {
   4042       Label packed_case;
   4043       // We might need a change here,
   4044       // look at the first argument.
   4045       __ lw(t1, MemOperand(sp, 0));
   4046       __ Branch(&packed_case, eq, t1, Operand(zero_reg));
   4047 
   4048       ElementsKind holey_kind = GetHoleyElementsKind(kind);
   4049       ArraySingleArgumentConstructorStub stub(isolate(),
   4050                                               holey_kind,
   4051                                               override_mode);
   4052       CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
   4053       __ jmp(&done);
   4054       __ bind(&packed_case);
   4055     }
   4056 
   4057     ArraySingleArgumentConstructorStub stub(isolate(), kind, override_mode);
   4058     CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
   4059     __ bind(&done);
   4060   } else {
   4061     ArrayNArgumentsConstructorStub stub(isolate(), kind, override_mode);
   4062     CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
   4063   }
   4064 }
   4065 
   4066 
   4067 void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
   4068   CallRuntime(instr->function(), instr->arity(), instr);
   4069 }
   4070 
   4071 
   4072 void LCodeGen::DoStoreCodeEntry(LStoreCodeEntry* instr) {
   4073   Register function = ToRegister(instr->function());
   4074   Register code_object = ToRegister(instr->code_object());
   4075   __ Addu(code_object, code_object,
   4076           Operand(Code::kHeaderSize - kHeapObjectTag));
   4077   __ sw(code_object,
   4078         FieldMemOperand(function, JSFunction::kCodeEntryOffset));
   4079 }
   4080 
   4081 
   4082 void LCodeGen::DoInnerAllocatedObject(LInnerAllocatedObject* instr) {
   4083   Register result = ToRegister(instr->result());
   4084   Register base = ToRegister(instr->base_object());
   4085   if (instr->offset()->IsConstantOperand()) {
   4086     LConstantOperand* offset = LConstantOperand::cast(instr->offset());
   4087     __ Addu(result, base, Operand(ToInteger32(offset)));
   4088   } else {
   4089     Register offset = ToRegister(instr->offset());
   4090     __ Addu(result, base, offset);
   4091   }
   4092 }
   4093 
   4094 
   4095 void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
   4096   Representation representation = instr->representation();
   4097 
   4098   Register object = ToRegister(instr->object());
   4099   Register scratch = scratch0();
   4100   HObjectAccess access = instr->hydrogen()->access();
   4101   int offset = access.offset();
   4102 
   4103   if (access.IsExternalMemory()) {
   4104     Register value = ToRegister(instr->value());
   4105     MemOperand operand = MemOperand(object, offset);
   4106     __ Store(value, operand, representation);
   4107     return;
   4108   }
   4109 
   4110   __ AssertNotSmi(object);
   4111 
   4112   DCHECK(!representation.IsSmi() ||
   4113          !instr->value()->IsConstantOperand() ||
   4114          IsSmi(LConstantOperand::cast(instr->value())));
   4115   if (representation.IsDouble()) {
   4116     DCHECK(access.IsInobject());
   4117     DCHECK(!instr->hydrogen()->has_transition());
   4118     DCHECK(!instr->hydrogen()->NeedsWriteBarrier());
   4119     DoubleRegister value = ToDoubleRegister(instr->value());
   4120     __ sdc1(value, FieldMemOperand(object, offset));
   4121     return;
   4122   }
   4123 
   4124   if (instr->hydrogen()->has_transition()) {
   4125     Handle<Map> transition = instr->hydrogen()->transition_map();
   4126     AddDeprecationDependency(transition);
   4127     __ li(scratch, Operand(transition));
   4128     __ sw(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
   4129     if (instr->hydrogen()->NeedsWriteBarrierForMap()) {
   4130       Register temp = ToRegister(instr->temp());
   4131       // Update the write barrier for the map field.
   4132       __ RecordWriteForMap(object,
   4133                            scratch,
   4134                            temp,
   4135                            GetRAState(),
   4136                            kSaveFPRegs);
   4137     }
   4138   }
   4139 
   4140   // Do the store.
   4141   Register value = ToRegister(instr->value());
   4142   if (access.IsInobject()) {
   4143     MemOperand operand = FieldMemOperand(object, offset);
   4144     __ Store(value, operand, representation);
   4145     if (instr->hydrogen()->NeedsWriteBarrier()) {
   4146       // Update the write barrier for the object for in-object properties.
   4147       __ RecordWriteField(object,
   4148                           offset,
   4149                           value,
   4150                           scratch,
   4151                           GetRAState(),
   4152                           kSaveFPRegs,
   4153                           EMIT_REMEMBERED_SET,
   4154                           instr->hydrogen()->SmiCheckForWriteBarrier(),
   4155                           instr->hydrogen()->PointersToHereCheckForValue());
   4156     }
   4157   } else {
   4158     __ lw(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
   4159     MemOperand operand = FieldMemOperand(scratch, offset);
   4160     __ Store(value, operand, representation);
   4161     if (instr->hydrogen()->NeedsWriteBarrier()) {
   4162       // Update the write barrier for the properties array.
   4163       // object is used as a scratch register.
   4164       __ RecordWriteField(scratch,
   4165                           offset,
   4166                           value,
   4167                           object,
   4168                           GetRAState(),
   4169                           kSaveFPRegs,
   4170                           EMIT_REMEMBERED_SET,
   4171                           instr->hydrogen()->SmiCheckForWriteBarrier(),
   4172                           instr->hydrogen()->PointersToHereCheckForValue());
   4173     }
   4174   }
   4175 }
   4176 
   4177 
   4178 void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
   4179   DCHECK(ToRegister(instr->context()).is(cp));
   4180   DCHECK(ToRegister(instr->object()).is(StoreDescriptor::ReceiverRegister()));
   4181   DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
   4182 
   4183   __ li(StoreDescriptor::NameRegister(), Operand(instr->name()));
   4184   Handle<Code> ic = StoreIC::initialize_stub(isolate(), instr->strict_mode());
   4185   CallCode(ic, RelocInfo::CODE_TARGET, instr);
   4186 }
   4187 
   4188 
   4189 void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
   4190   Condition cc = instr->hydrogen()->allow_equality() ? hi : hs;
   4191   Operand operand(0);
   4192   Register reg;
   4193   if (instr->index()->IsConstantOperand()) {
   4194     operand = ToOperand(instr->index());
   4195     reg = ToRegister(instr->length());
   4196     cc = CommuteCondition(cc);
   4197   } else {
   4198     reg = ToRegister(instr->index());
   4199     operand = ToOperand(instr->length());
   4200   }
   4201   if (FLAG_debug_code && instr->hydrogen()->skip_check()) {
   4202     Label done;
   4203     __ Branch(&done, NegateCondition(cc), reg, operand);
   4204     __ stop("eliminated bounds check failed");
   4205     __ bind(&done);
   4206   } else {
   4207     DeoptimizeIf(cc, instr, reg, operand);
   4208   }
   4209 }
   4210 
   4211 
   4212 void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
   4213   Register external_pointer = ToRegister(instr->elements());
   4214   Register key = no_reg;
   4215   ElementsKind elements_kind = instr->elements_kind();
   4216   bool key_is_constant = instr->key()->IsConstantOperand();
   4217   int constant_key = 0;
   4218   if (key_is_constant) {
   4219     constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
   4220     if (constant_key & 0xF0000000) {
   4221       Abort(kArrayIndexConstantValueTooBig);
   4222     }
   4223   } else {
   4224     key = ToRegister(instr->key());
   4225   }
   4226   int element_size_shift = ElementsKindToShiftSize(elements_kind);
   4227   int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
   4228       ? (element_size_shift - kSmiTagSize) : element_size_shift;
   4229   int base_offset = instr->base_offset();
   4230 
   4231   if (elements_kind == EXTERNAL_FLOAT32_ELEMENTS ||
   4232       elements_kind == FLOAT32_ELEMENTS ||
   4233       elements_kind == EXTERNAL_FLOAT64_ELEMENTS ||
   4234       elements_kind == FLOAT64_ELEMENTS) {
   4235     Register address = scratch0();
   4236     FPURegister value(ToDoubleRegister(instr->value()));
   4237     if (key_is_constant) {
   4238       if (constant_key != 0) {
   4239         __ Addu(address, external_pointer,
   4240                 Operand(constant_key << element_size_shift));
   4241       } else {
   4242         address = external_pointer;
   4243       }
   4244     } else {
   4245       __ sll(address, key, shift_size);
   4246       __ Addu(address, external_pointer, address);
   4247     }
   4248 
   4249     if (elements_kind == EXTERNAL_FLOAT32_ELEMENTS ||
   4250         elements_kind == FLOAT32_ELEMENTS) {
   4251       __ cvt_s_d(double_scratch0(), value);
   4252       __ swc1(double_scratch0(), MemOperand(address, base_offset));
   4253     } else {  // Storing doubles, not floats.
   4254       __ sdc1(value, MemOperand(address, base_offset));
   4255     }
   4256   } else {
   4257     Register value(ToRegister(instr->value()));
   4258     MemOperand mem_operand = PrepareKeyedOperand(
   4259         key, external_pointer, key_is_constant, constant_key,
   4260         element_size_shift, shift_size,
   4261         base_offset);
   4262     switch (elements_kind) {
   4263       case EXTERNAL_UINT8_CLAMPED_ELEMENTS:
   4264       case EXTERNAL_INT8_ELEMENTS:
   4265       case EXTERNAL_UINT8_ELEMENTS:
   4266       case UINT8_ELEMENTS:
   4267       case UINT8_CLAMPED_ELEMENTS:
   4268       case INT8_ELEMENTS:
   4269         __ sb(value, mem_operand);
   4270         break;
   4271       case EXTERNAL_INT16_ELEMENTS:
   4272       case EXTERNAL_UINT16_ELEMENTS:
   4273       case INT16_ELEMENTS:
   4274       case UINT16_ELEMENTS:
   4275         __ sh(value, mem_operand);
   4276         break;
   4277       case EXTERNAL_INT32_ELEMENTS:
   4278       case EXTERNAL_UINT32_ELEMENTS:
   4279       case INT32_ELEMENTS:
   4280       case UINT32_ELEMENTS:
   4281         __ sw(value, mem_operand);
   4282         break;
   4283       case FLOAT32_ELEMENTS:
   4284       case FLOAT64_ELEMENTS:
   4285       case EXTERNAL_FLOAT32_ELEMENTS:
   4286       case EXTERNAL_FLOAT64_ELEMENTS:
   4287       case FAST_DOUBLE_ELEMENTS:
   4288       case FAST_ELEMENTS:
   4289       case FAST_SMI_ELEMENTS:
   4290       case FAST_HOLEY_DOUBLE_ELEMENTS:
   4291       case FAST_HOLEY_ELEMENTS:
   4292       case FAST_HOLEY_SMI_ELEMENTS:
   4293       case DICTIONARY_ELEMENTS:
   4294       case SLOPPY_ARGUMENTS_ELEMENTS:
   4295         UNREACHABLE();
   4296         break;
   4297     }
   4298   }
   4299 }
   4300 
   4301 
   4302 void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
   4303   DoubleRegister value = ToDoubleRegister(instr->value());
   4304   Register elements = ToRegister(instr->elements());
   4305   Register scratch = scratch0();
   4306   DoubleRegister double_scratch = double_scratch0();
   4307   bool key_is_constant = instr->key()->IsConstantOperand();
   4308   int base_offset = instr->base_offset();
   4309   Label not_nan, done;
   4310 
   4311   // Calculate the effective address of the slot in the array to store the
   4312   // double value.
   4313   int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
   4314   if (key_is_constant) {
   4315     int constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
   4316     if (constant_key & 0xF0000000) {
   4317       Abort(kArrayIndexConstantValueTooBig);
   4318     }
   4319     __ Addu(scratch, elements,
   4320            Operand((constant_key << element_size_shift) + base_offset));
   4321   } else {
   4322     int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
   4323         ? (element_size_shift - kSmiTagSize) : element_size_shift;
   4324     __ Addu(scratch, elements, Operand(base_offset));
   4325     __ sll(at, ToRegister(instr->key()), shift_size);
   4326     __ Addu(scratch, scratch, at);
   4327   }
   4328 
   4329   if (instr->NeedsCanonicalization()) {
   4330     Label is_nan;
   4331     // Check for NaN. All NaNs must be canonicalized.
   4332     __ BranchF(NULL, &is_nan, eq, value, value);
   4333     __ Branch(&not_nan);
   4334 
   4335     // Only load canonical NaN if the comparison above set the overflow.
   4336     __ bind(&is_nan);
   4337     __ LoadRoot(at, Heap::kNanValueRootIndex);
   4338     __ ldc1(double_scratch, FieldMemOperand(at, HeapNumber::kValueOffset));
   4339     __ sdc1(double_scratch, MemOperand(scratch, 0));
   4340     __ Branch(&done);
   4341   }
   4342 
   4343   __ bind(&not_nan);
   4344   __ sdc1(value, MemOperand(scratch, 0));
   4345   __ bind(&done);
   4346 }
   4347 
   4348 
   4349 void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
   4350   Register value = ToRegister(instr->value());
   4351   Register elements = ToRegister(instr->elements());
   4352   Register key = instr->key()->IsRegister() ? ToRegister(instr->key())
   4353       : no_reg;
   4354   Register scratch = scratch0();
   4355   Register store_base = scratch;
   4356   int offset = instr->base_offset();
   4357 
   4358   // Do the store.
   4359   if (instr->key()->IsConstantOperand()) {
   4360     DCHECK(!instr->hydrogen()->NeedsWriteBarrier());
   4361     LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
   4362     offset += ToInteger32(const_operand) * kPointerSize;
   4363     store_base = elements;
   4364   } else {
   4365     // Even though the HLoadKeyed instruction forces the input
   4366     // representation for the key to be an integer, the input gets replaced
   4367     // during bound check elimination with the index argument to the bounds
   4368     // check, which can be tagged, so that case must be handled here, too.
   4369     if (instr->hydrogen()->key()->representation().IsSmi()) {
   4370       __ sll(scratch, key, kPointerSizeLog2 - kSmiTagSize);
   4371       __ addu(scratch, elements, scratch);
   4372     } else {
   4373       __ sll(scratch, key, kPointerSizeLog2);
   4374       __ addu(scratch, elements, scratch);
   4375     }
   4376   }
   4377   __ sw(value, MemOperand(store_base, offset));
   4378 
   4379   if (instr->hydrogen()->NeedsWriteBarrier()) {
   4380     SmiCheck check_needed =
   4381         instr->hydrogen()->value()->type().IsHeapObject()
   4382             ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
   4383     // Compute address of modified element and store it into key register.
   4384     __ Addu(key, store_base, Operand(offset));
   4385     __ RecordWrite(elements,
   4386                    key,
   4387                    value,
   4388                    GetRAState(),
   4389                    kSaveFPRegs,
   4390                    EMIT_REMEMBERED_SET,
   4391                    check_needed,
   4392                    instr->hydrogen()->PointersToHereCheckForValue());
   4393   }
   4394 }
   4395 
   4396 
   4397 void LCodeGen::DoStoreKeyed(LStoreKeyed* instr) {
   4398   // By cases: external, fast double
   4399   if (instr->is_typed_elements()) {
   4400     DoStoreKeyedExternalArray(instr);
   4401   } else if (instr->hydrogen()->value()->representation().IsDouble()) {
   4402     DoStoreKeyedFixedDoubleArray(instr);
   4403   } else {
   4404     DoStoreKeyedFixedArray(instr);
   4405   }
   4406 }
   4407 
   4408 
   4409 void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
   4410   DCHECK(ToRegister(instr->context()).is(cp));
   4411   DCHECK(ToRegister(instr->object()).is(StoreDescriptor::ReceiverRegister()));
   4412   DCHECK(ToRegister(instr->key()).is(StoreDescriptor::NameRegister()));
   4413   DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
   4414 
   4415   Handle<Code> ic =
   4416       CodeFactory::KeyedStoreIC(isolate(), instr->strict_mode()).code();
   4417   CallCode(ic, RelocInfo::CODE_TARGET, instr);
   4418 }
   4419 
   4420 
   4421 void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
   4422   Register object_reg = ToRegister(instr->object());
   4423   Register scratch = scratch0();
   4424 
   4425   Handle<Map> from_map = instr->original_map();
   4426   Handle<Map> to_map = instr->transitioned_map();
   4427   ElementsKind from_kind = instr->from_kind();
   4428   ElementsKind to_kind = instr->to_kind();
   4429 
   4430   Label not_applicable;
   4431   __ lw(scratch, FieldMemOperand(object_reg, HeapObject::kMapOffset));
   4432   __ Branch(&not_applicable, ne, scratch, Operand(from_map));
   4433 
   4434   if (IsSimpleMapChangeTransition(from_kind, to_kind)) {
   4435     Register new_map_reg = ToRegister(instr->new_map_temp());
   4436     __ li(new_map_reg, Operand(to_map));
   4437     __ sw(new_map_reg, FieldMemOperand(object_reg, HeapObject::kMapOffset));
   4438     // Write barrier.
   4439     __ RecordWriteForMap(object_reg,
   4440                          new_map_reg,
   4441                          scratch,
   4442                          GetRAState(),
   4443                          kDontSaveFPRegs);
   4444   } else {
   4445     DCHECK(object_reg.is(a0));
   4446     DCHECK(ToRegister(instr->context()).is(cp));
   4447     PushSafepointRegistersScope scope(this);
   4448     __ li(a1, Operand(to_map));
   4449     bool is_js_array = from_map->instance_type() == JS_ARRAY_TYPE;
   4450     TransitionElementsKindStub stub(isolate(), from_kind, to_kind, is_js_array);
   4451     __ CallStub(&stub);
   4452     RecordSafepointWithRegisters(
   4453         instr->pointer_map(), 0, Safepoint::kLazyDeopt);
   4454   }
   4455   __ bind(&not_applicable);
   4456 }
   4457 
   4458 
   4459 void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
   4460   Register object = ToRegister(instr->object());
   4461   Register temp = ToRegister(instr->temp());
   4462   Label no_memento_found;
   4463   __ TestJSArrayForAllocationMemento(object, temp, &no_memento_found,
   4464                                      ne, &no_memento_found);
   4465   DeoptimizeIf(al, instr);
   4466   __ bind(&no_memento_found);
   4467 }
   4468 
   4469 
   4470 void LCodeGen::DoStringAdd(LStringAdd* instr) {
   4471   DCHECK(ToRegister(instr->context()).is(cp));
   4472   DCHECK(ToRegister(instr->left()).is(a1));
   4473   DCHECK(ToRegister(instr->right()).is(a0));
   4474   StringAddStub stub(isolate(),
   4475                      instr->hydrogen()->flags(),
   4476                      instr->hydrogen()->pretenure_flag());
   4477   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   4478 }
   4479 
   4480 
   4481 void LCodeGen::DoStringCharCodeAt(LStringCharCodeAt* instr) {
   4482   class DeferredStringCharCodeAt FINAL : public LDeferredCode {
   4483    public:
   4484     DeferredStringCharCodeAt(LCodeGen* codegen, LStringCharCodeAt* instr)
   4485         : LDeferredCode(codegen), instr_(instr) { }
   4486     virtual void Generate() OVERRIDE {
   4487       codegen()->DoDeferredStringCharCodeAt(instr_);
   4488     }
   4489     virtual LInstruction* instr() OVERRIDE { return instr_; }
   4490    private:
   4491     LStringCharCodeAt* instr_;
   4492   };
   4493 
   4494   DeferredStringCharCodeAt* deferred =
   4495       new(zone()) DeferredStringCharCodeAt(this, instr);
   4496   StringCharLoadGenerator::Generate(masm(),
   4497                                     ToRegister(instr->string()),
   4498                                     ToRegister(instr->index()),
   4499                                     ToRegister(instr->result()),
   4500                                     deferred->entry());
   4501   __ bind(deferred->exit());
   4502 }
   4503 
   4504 
   4505 void LCodeGen::DoDeferredStringCharCodeAt(LStringCharCodeAt* instr) {
   4506   Register string = ToRegister(instr->string());
   4507   Register result = ToRegister(instr->result());
   4508   Register scratch = scratch0();
   4509 
   4510   // TODO(3095996): Get rid of this. For now, we need to make the
   4511   // result register contain a valid pointer because it is already
   4512   // contained in the register pointer map.
   4513   __ mov(result, zero_reg);
   4514 
   4515   PushSafepointRegistersScope scope(this);
   4516   __ push(string);
   4517   // Push the index as a smi. This is safe because of the checks in
   4518   // DoStringCharCodeAt above.
   4519   if (instr->index()->IsConstantOperand()) {
   4520     int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
   4521     __ Addu(scratch, zero_reg, Operand(Smi::FromInt(const_index)));
   4522     __ push(scratch);
   4523   } else {
   4524     Register index = ToRegister(instr->index());
   4525     __ SmiTag(index);
   4526     __ push(index);
   4527   }
   4528   CallRuntimeFromDeferred(Runtime::kStringCharCodeAtRT, 2, instr,
   4529                           instr->context());
   4530   __ AssertSmi(v0);
   4531   __ SmiUntag(v0);
   4532   __ StoreToSafepointRegisterSlot(v0, result);
   4533 }
   4534 
   4535 
   4536 void LCodeGen::DoStringCharFromCode(LStringCharFromCode* instr) {
   4537   class DeferredStringCharFromCode FINAL : public LDeferredCode {
   4538    public:
   4539     DeferredStringCharFromCode(LCodeGen* codegen, LStringCharFromCode* instr)
   4540         : LDeferredCode(codegen), instr_(instr) { }
   4541     virtual void Generate() OVERRIDE {
   4542       codegen()->DoDeferredStringCharFromCode(instr_);
   4543     }
   4544     virtual LInstruction* instr() OVERRIDE { return instr_; }
   4545    private:
   4546     LStringCharFromCode* instr_;
   4547   };
   4548 
   4549   DeferredStringCharFromCode* deferred =
   4550       new(zone()) DeferredStringCharFromCode(this, instr);
   4551 
   4552   DCHECK(instr->hydrogen()->value()->representation().IsInteger32());
   4553   Register char_code = ToRegister(instr->char_code());
   4554   Register result = ToRegister(instr->result());
   4555   Register scratch = scratch0();
   4556   DCHECK(!char_code.is(result));
   4557 
   4558   __ Branch(deferred->entry(), hi,
   4559             char_code, Operand(String::kMaxOneByteCharCode));
   4560   __ LoadRoot(result, Heap::kSingleCharacterStringCacheRootIndex);
   4561   __ sll(scratch, char_code, kPointerSizeLog2);
   4562   __ Addu(result, result, scratch);
   4563   __ lw(result, FieldMemOperand(result, FixedArray::kHeaderSize));
   4564   __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   4565   __ Branch(deferred->entry(), eq, result, Operand(scratch));
   4566   __ bind(deferred->exit());
   4567 }
   4568 
   4569 
   4570 void LCodeGen::DoDeferredStringCharFromCode(LStringCharFromCode* instr) {
   4571   Register char_code = ToRegister(instr->char_code());
   4572   Register result = ToRegister(instr->result());
   4573 
   4574   // TODO(3095996): Get rid of this. For now, we need to make the
   4575   // result register contain a valid pointer because it is already
   4576   // contained in the register pointer map.
   4577   __ mov(result, zero_reg);
   4578 
   4579   PushSafepointRegistersScope scope(this);
   4580   __ SmiTag(char_code);
   4581   __ push(char_code);
   4582   CallRuntimeFromDeferred(Runtime::kCharFromCode, 1, instr, instr->context());
   4583   __ StoreToSafepointRegisterSlot(v0, result);
   4584 }
   4585 
   4586 
   4587 void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
   4588   LOperand* input = instr->value();
   4589   DCHECK(input->IsRegister() || input->IsStackSlot());
   4590   LOperand* output = instr->result();
   4591   DCHECK(output->IsDoubleRegister());
   4592   FPURegister single_scratch = double_scratch0().low();
   4593   if (input->IsStackSlot()) {
   4594     Register scratch = scratch0();
   4595     __ lw(scratch, ToMemOperand(input));
   4596     __ mtc1(scratch, single_scratch);
   4597   } else {
   4598     __ mtc1(ToRegister(input), single_scratch);
   4599   }
   4600   __ cvt_d_w(ToDoubleRegister(output), single_scratch);
   4601 }
   4602 
   4603 
   4604 void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
   4605   LOperand* input = instr->value();
   4606   LOperand* output = instr->result();
   4607 
   4608   FPURegister dbl_scratch = double_scratch0();
   4609   __ mtc1(ToRegister(input), dbl_scratch);
   4610   __ Cvt_d_uw(ToDoubleRegister(output), dbl_scratch, f22);
   4611 }
   4612 
   4613 
   4614 void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
   4615   class DeferredNumberTagI FINAL : public LDeferredCode {
   4616    public:
   4617     DeferredNumberTagI(LCodeGen* codegen, LNumberTagI* instr)
   4618         : LDeferredCode(codegen), instr_(instr) { }
   4619     virtual void Generate() OVERRIDE {
   4620       codegen()->DoDeferredNumberTagIU(instr_,
   4621                                        instr_->value(),
   4622                                        instr_->temp1(),
   4623                                        instr_->temp2(),
   4624                                        SIGNED_INT32);
   4625     }
   4626     virtual LInstruction* instr() OVERRIDE { return instr_; }
   4627    private:
   4628     LNumberTagI* instr_;
   4629   };
   4630 
   4631   Register src = ToRegister(instr->value());
   4632   Register dst = ToRegister(instr->result());
   4633   Register overflow = scratch0();
   4634 
   4635   DeferredNumberTagI* deferred = new(zone()) DeferredNumberTagI(this, instr);
   4636   __ SmiTagCheckOverflow(dst, src, overflow);
   4637   __ BranchOnOverflow(deferred->entry(), overflow);
   4638   __ bind(deferred->exit());
   4639 }
   4640 
   4641 
   4642 void LCodeGen::DoNumberTagU(LNumberTagU* instr) {
   4643   class DeferredNumberTagU FINAL : public LDeferredCode {
   4644    public:
   4645     DeferredNumberTagU(LCodeGen* codegen, LNumberTagU* instr)
   4646         : LDeferredCode(codegen), instr_(instr) { }
   4647     virtual void Generate() OVERRIDE {
   4648       codegen()->DoDeferredNumberTagIU(instr_,
   4649                                        instr_->value(),
   4650                                        instr_->temp1(),
   4651                                        instr_->temp2(),
   4652                                        UNSIGNED_INT32);
   4653     }
   4654     virtual LInstruction* instr() OVERRIDE { return instr_; }
   4655    private:
   4656     LNumberTagU* instr_;
   4657   };
   4658 
   4659   Register input = ToRegister(instr->value());
   4660   Register result = ToRegister(instr->result());
   4661 
   4662   DeferredNumberTagU* deferred = new(zone()) DeferredNumberTagU(this, instr);
   4663   __ Branch(deferred->entry(), hi, input, Operand(Smi::kMaxValue));
   4664   __ SmiTag(result, input);
   4665   __ bind(deferred->exit());
   4666 }
   4667 
   4668 
   4669 void LCodeGen::DoDeferredNumberTagIU(LInstruction* instr,
   4670                                      LOperand* value,
   4671                                      LOperand* temp1,
   4672                                      LOperand* temp2,
   4673                                      IntegerSignedness signedness) {
   4674   Label done, slow;
   4675   Register src = ToRegister(value);
   4676   Register dst = ToRegister(instr->result());
   4677   Register tmp1 = scratch0();
   4678   Register tmp2 = ToRegister(temp1);
   4679   Register tmp3 = ToRegister(temp2);
   4680   DoubleRegister dbl_scratch = double_scratch0();
   4681 
   4682   if (signedness == SIGNED_INT32) {
   4683     // There was overflow, so bits 30 and 31 of the original integer
   4684     // disagree. Try to allocate a heap number in new space and store
   4685     // the value in there. If that fails, call the runtime system.
   4686     if (dst.is(src)) {
   4687       __ SmiUntag(src, dst);
   4688       __ Xor(src, src, Operand(0x80000000));
   4689     }
   4690     __ mtc1(src, dbl_scratch);
   4691     __ cvt_d_w(dbl_scratch, dbl_scratch);
   4692   } else {
   4693     __ mtc1(src, dbl_scratch);
   4694     __ Cvt_d_uw(dbl_scratch, dbl_scratch, f22);
   4695   }
   4696 
   4697   if (FLAG_inline_new) {
   4698     __ LoadRoot(tmp3, Heap::kHeapNumberMapRootIndex);
   4699     __ AllocateHeapNumber(dst, tmp1, tmp2, tmp3, &slow, DONT_TAG_RESULT);
   4700     __ Branch(&done);
   4701   }
   4702 
   4703   // Slow case: Call the runtime system to do the number allocation.
   4704   __ bind(&slow);
   4705   {
   4706     // TODO(3095996): Put a valid pointer value in the stack slot where the
   4707     // result register is stored, as this register is in the pointer map, but
   4708     // contains an integer value.
   4709     __ mov(dst, zero_reg);
   4710 
   4711     // Preserve the value of all registers.
   4712     PushSafepointRegistersScope scope(this);
   4713 
   4714     // NumberTagI and NumberTagD use the context from the frame, rather than
   4715     // the environment's HContext or HInlinedContext value.
   4716     // They only call Runtime::kAllocateHeapNumber.
   4717     // The corresponding HChange instructions are added in a phase that does
   4718     // not have easy access to the local context.
   4719     __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   4720     __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
   4721     RecordSafepointWithRegisters(
   4722         instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
   4723     __ Subu(v0, v0, kHeapObjectTag);
   4724     __ StoreToSafepointRegisterSlot(v0, dst);
   4725   }
   4726 
   4727 
   4728   // Done. Put the value in dbl_scratch into the value of the allocated heap
   4729   // number.
   4730   __ bind(&done);
   4731   __ sdc1(dbl_scratch, MemOperand(dst, HeapNumber::kValueOffset));
   4732   __ Addu(dst, dst, kHeapObjectTag);
   4733 }
   4734 
   4735 
   4736 void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
   4737   class DeferredNumberTagD FINAL : public LDeferredCode {
   4738    public:
   4739     DeferredNumberTagD(LCodeGen* codegen, LNumberTagD* instr)
   4740         : LDeferredCode(codegen), instr_(instr) { }
   4741     virtual void Generate() OVERRIDE {
   4742       codegen()->DoDeferredNumberTagD(instr_);
   4743     }
   4744     virtual LInstruction* instr() OVERRIDE { return instr_; }
   4745    private:
   4746     LNumberTagD* instr_;
   4747   };
   4748 
   4749   DoubleRegister input_reg = ToDoubleRegister(instr->value());
   4750   Register scratch = scratch0();
   4751   Register reg = ToRegister(instr->result());
   4752   Register temp1 = ToRegister(instr->temp());
   4753   Register temp2 = ToRegister(instr->temp2());
   4754 
   4755   DeferredNumberTagD* deferred = new(zone()) DeferredNumberTagD(this, instr);
   4756   if (FLAG_inline_new) {
   4757     __ LoadRoot(scratch, Heap::kHeapNumberMapRootIndex);
   4758     // We want the untagged address first for performance
   4759     __ AllocateHeapNumber(reg, temp1, temp2, scratch, deferred->entry(),
   4760                           DONT_TAG_RESULT);
   4761   } else {
   4762     __ Branch(deferred->entry());
   4763   }
   4764   __ bind(deferred->exit());
   4765   __ sdc1(input_reg, MemOperand(reg, HeapNumber::kValueOffset));
   4766   // Now that we have finished with the object's real address tag it
   4767   __ Addu(reg, reg, kHeapObjectTag);
   4768 }
   4769 
   4770 
   4771 void LCodeGen::DoDeferredNumberTagD(LNumberTagD* instr) {
   4772   // TODO(3095996): Get rid of this. For now, we need to make the
   4773   // result register contain a valid pointer because it is already
   4774   // contained in the register pointer map.
   4775   Register reg = ToRegister(instr->result());
   4776   __ mov(reg, zero_reg);
   4777 
   4778   PushSafepointRegistersScope scope(this);
   4779   // NumberTagI and NumberTagD use the context from the frame, rather than
   4780   // the environment's HContext or HInlinedContext value.
   4781   // They only call Runtime::kAllocateHeapNumber.
   4782   // The corresponding HChange instructions are added in a phase that does
   4783   // not have easy access to the local context.
   4784   __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   4785   __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
   4786   RecordSafepointWithRegisters(
   4787       instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
   4788   __ Subu(v0, v0, kHeapObjectTag);
   4789   __ StoreToSafepointRegisterSlot(v0, reg);
   4790 }
   4791 
   4792 
   4793 void LCodeGen::DoSmiTag(LSmiTag* instr) {
   4794   HChange* hchange = instr->hydrogen();
   4795   Register input = ToRegister(instr->value());
   4796   Register output = ToRegister(instr->result());
   4797   if (hchange->CheckFlag(HValue::kCanOverflow) &&
   4798       hchange->value()->CheckFlag(HValue::kUint32)) {
   4799     __ And(at, input, Operand(0xc0000000));
   4800     DeoptimizeIf(ne, instr, at, Operand(zero_reg));
   4801   }
   4802   if (hchange->CheckFlag(HValue::kCanOverflow) &&
   4803       !hchange->value()->CheckFlag(HValue::kUint32)) {
   4804     __ SmiTagCheckOverflow(output, input, at);
   4805     DeoptimizeIf(lt, instr, at, Operand(zero_reg));
   4806   } else {
   4807     __ SmiTag(output, input);
   4808   }
   4809 }
   4810 
   4811 
   4812 void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
   4813   Register scratch = scratch0();
   4814   Register input = ToRegister(instr->value());
   4815   Register result = ToRegister(instr->result());
   4816   if (instr->needs_check()) {
   4817     STATIC_ASSERT(kHeapObjectTag == 1);
   4818     // If the input is a HeapObject, value of scratch won't be zero.
   4819     __ And(scratch, input, Operand(kHeapObjectTag));
   4820     __ SmiUntag(result, input);
   4821     DeoptimizeIf(ne, instr, scratch, Operand(zero_reg));
   4822   } else {
   4823     __ SmiUntag(result, input);
   4824   }
   4825 }
   4826 
   4827 
   4828 void LCodeGen::EmitNumberUntagD(LNumberUntagD* instr, Register input_reg,
   4829                                 DoubleRegister result_reg,
   4830                                 NumberUntagDMode mode) {
   4831   bool can_convert_undefined_to_nan =
   4832       instr->hydrogen()->can_convert_undefined_to_nan();
   4833   bool deoptimize_on_minus_zero = instr->hydrogen()->deoptimize_on_minus_zero();
   4834 
   4835   Register scratch = scratch0();
   4836   Label convert, load_smi, done;
   4837   if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
   4838     // Smi check.
   4839     __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);
   4840     // Heap number map check.
   4841     __ lw(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
   4842     __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
   4843     if (can_convert_undefined_to_nan) {
   4844       __ Branch(&convert, ne, scratch, Operand(at));
   4845     } else {
   4846       DeoptimizeIf(ne, instr, scratch, Operand(at));
   4847     }
   4848     // Load heap number.
   4849     __ ldc1(result_reg, FieldMemOperand(input_reg, HeapNumber::kValueOffset));
   4850     if (deoptimize_on_minus_zero) {
   4851       __ mfc1(at, result_reg.low());
   4852       __ Branch(&done, ne, at, Operand(zero_reg));
   4853       __ Mfhc1(scratch, result_reg);
   4854       DeoptimizeIf(eq, instr, scratch, Operand(HeapNumber::kSignMask));
   4855     }
   4856     __ Branch(&done);
   4857     if (can_convert_undefined_to_nan) {
   4858       __ bind(&convert);
   4859       // Convert undefined (and hole) to NaN.
   4860       __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   4861       DeoptimizeIf(ne, instr, input_reg, Operand(at));
   4862       __ LoadRoot(scratch, Heap::kNanValueRootIndex);
   4863       __ ldc1(result_reg, FieldMemOperand(scratch, HeapNumber::kValueOffset));
   4864       __ Branch(&done);
   4865     }
   4866   } else {
   4867     __ SmiUntag(scratch, input_reg);
   4868     DCHECK(mode == NUMBER_CANDIDATE_IS_SMI);
   4869   }
   4870   // Smi to double register conversion
   4871   __ bind(&load_smi);
   4872   // scratch: untagged value of input_reg
   4873   __ mtc1(scratch, result_reg);
   4874   __ cvt_d_w(result_reg, result_reg);
   4875   __ bind(&done);
   4876 }
   4877 
   4878 
   4879 void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
   4880   Register input_reg = ToRegister(instr->value());
   4881   Register scratch1 = scratch0();
   4882   Register scratch2 = ToRegister(instr->temp());
   4883   DoubleRegister double_scratch = double_scratch0();
   4884   DoubleRegister double_scratch2 = ToDoubleRegister(instr->temp2());
   4885 
   4886   DCHECK(!scratch1.is(input_reg) && !scratch1.is(scratch2));
   4887   DCHECK(!scratch2.is(input_reg) && !scratch2.is(scratch1));
   4888 
   4889   Label done;
   4890 
   4891   // The input is a tagged HeapObject.
   4892   // Heap number map check.
   4893   __ lw(scratch1, FieldMemOperand(input_reg, HeapObject::kMapOffset));
   4894   __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
   4895   // This 'at' value and scratch1 map value are used for tests in both clauses
   4896   // of the if.
   4897 
   4898   if (instr->truncating()) {
   4899     // Performs a truncating conversion of a floating point number as used by
   4900     // the JS bitwise operations.
   4901     Label no_heap_number, check_bools, check_false;
   4902     // Check HeapNumber map.
   4903     __ Branch(USE_DELAY_SLOT, &no_heap_number, ne, scratch1, Operand(at));
   4904     __ mov(scratch2, input_reg);  // In delay slot.
   4905     __ TruncateHeapNumberToI(input_reg, scratch2);
   4906     __ Branch(&done);
   4907 
   4908     // Check for Oddballs. Undefined/False is converted to zero and True to one
   4909     // for truncating conversions.
   4910     __ bind(&no_heap_number);
   4911     __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   4912     __ Branch(&check_bools, ne, input_reg, Operand(at));
   4913     DCHECK(ToRegister(instr->result()).is(input_reg));
   4914     __ Branch(USE_DELAY_SLOT, &done);
   4915     __ mov(input_reg, zero_reg);  // In delay slot.
   4916 
   4917     __ bind(&check_bools);
   4918     __ LoadRoot(at, Heap::kTrueValueRootIndex);
   4919     __ Branch(&check_false, ne, scratch2, Operand(at));
   4920     __ Branch(USE_DELAY_SLOT, &done);
   4921     __ li(input_reg, Operand(1));  // In delay slot.
   4922 
   4923     __ bind(&check_false);
   4924     __ LoadRoot(at, Heap::kFalseValueRootIndex);
   4925     DeoptimizeIf(ne, instr, scratch2, Operand(at), "cannot truncate");
   4926     __ Branch(USE_DELAY_SLOT, &done);
   4927     __ mov(input_reg, zero_reg);  // In delay slot.
   4928   } else {
   4929     DeoptimizeIf(ne, instr, scratch1, Operand(at), "not a heap number");
   4930 
   4931     // Load the double value.
   4932     __ ldc1(double_scratch,
   4933             FieldMemOperand(input_reg, HeapNumber::kValueOffset));
   4934 
   4935     Register except_flag = scratch2;
   4936     __ EmitFPUTruncate(kRoundToZero,
   4937                        input_reg,
   4938                        double_scratch,
   4939                        scratch1,
   4940                        double_scratch2,
   4941                        except_flag,
   4942                        kCheckForInexactConversion);
   4943 
   4944     DeoptimizeIf(ne, instr, except_flag, Operand(zero_reg),
   4945                  "lost precision or NaN");
   4946 
   4947     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
   4948       __ Branch(&done, ne, input_reg, Operand(zero_reg));
   4949 
   4950       __ Mfhc1(scratch1, double_scratch);
   4951       __ And(scratch1, scratch1, Operand(HeapNumber::kSignMask));
   4952       DeoptimizeIf(ne, instr, scratch1, Operand(zero_reg), "minus zero");
   4953     }
   4954   }
   4955   __ bind(&done);
   4956 }
   4957 
   4958 
   4959 void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
   4960   class DeferredTaggedToI FINAL : public LDeferredCode {
   4961    public:
   4962     DeferredTaggedToI(LCodeGen* codegen, LTaggedToI* instr)
   4963         : LDeferredCode(codegen), instr_(instr) { }
   4964     virtual void Generate() OVERRIDE {
   4965       codegen()->DoDeferredTaggedToI(instr_);
   4966     }
   4967     virtual LInstruction* instr() OVERRIDE { return instr_; }
   4968    private:
   4969     LTaggedToI* instr_;
   4970   };
   4971 
   4972   LOperand* input = instr->value();
   4973   DCHECK(input->IsRegister());
   4974   DCHECK(input->Equals(instr->result()));
   4975 
   4976   Register input_reg = ToRegister(input);
   4977 
   4978   if (instr->hydrogen()->value()->representation().IsSmi()) {
   4979     __ SmiUntag(input_reg);
   4980   } else {
   4981     DeferredTaggedToI* deferred = new(zone()) DeferredTaggedToI(this, instr);
   4982 
   4983     // Let the deferred code handle the HeapObject case.
   4984     __ JumpIfNotSmi(input_reg, deferred->entry());
   4985 
   4986     // Smi to int32 conversion.
   4987     __ SmiUntag(input_reg);
   4988     __ bind(deferred->exit());
   4989   }
   4990 }
   4991 
   4992 
   4993 void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
   4994   LOperand* input = instr->value();
   4995   DCHECK(input->IsRegister());
   4996   LOperand* result = instr->result();
   4997   DCHECK(result->IsDoubleRegister());
   4998 
   4999   Register input_reg = ToRegister(input);
   5000   DoubleRegister result_reg = ToDoubleRegister(result);
   5001 
   5002   HValue* value = instr->hydrogen()->value();
   5003   NumberUntagDMode mode = value->representation().IsSmi()
   5004       ? NUMBER_CANDIDATE_IS_SMI : NUMBER_CANDIDATE_IS_ANY_TAGGED;
   5005 
   5006   EmitNumberUntagD(instr, input_reg, result_reg, mode);
   5007 }
   5008 
   5009 
   5010 void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
   5011   Register result_reg = ToRegister(instr->result());
   5012   Register scratch1 = scratch0();
   5013   DoubleRegister double_input = ToDoubleRegister(instr->value());
   5014 
   5015   if (instr->truncating()) {
   5016     __ TruncateDoubleToI(result_reg, double_input);
   5017   } else {
   5018     Register except_flag = LCodeGen::scratch1();
   5019 
   5020     __ EmitFPUTruncate(kRoundToMinusInf,
   5021                        result_reg,
   5022                        double_input,
   5023                        scratch1,
   5024                        double_scratch0(),
   5025                        except_flag,
   5026                        kCheckForInexactConversion);
   5027 
   5028     // Deopt if the operation did not succeed (except_flag != 0).
   5029     DeoptimizeIf(ne, instr, except_flag, Operand(zero_reg));
   5030 
   5031     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
   5032       Label done;
   5033       __ Branch(&done, ne, result_reg, Operand(zero_reg));
   5034       __ Mfhc1(scratch1, double_input);
   5035       __ And(scratch1, scratch1, Operand(HeapNumber::kSignMask));
   5036       DeoptimizeIf(ne, instr, scratch1, Operand(zero_reg));
   5037       __ bind(&done);
   5038     }
   5039   }
   5040 }
   5041 
   5042 
   5043 void LCodeGen::DoDoubleToSmi(LDoubleToSmi* instr) {
   5044   Register result_reg = ToRegister(instr->result());
   5045   Register scratch1 = LCodeGen::scratch0();
   5046   DoubleRegister double_input = ToDoubleRegister(instr->value());
   5047 
   5048   if (instr->truncating()) {
   5049     __ TruncateDoubleToI(result_reg, double_input);
   5050   } else {
   5051     Register except_flag = LCodeGen::scratch1();
   5052 
   5053     __ EmitFPUTruncate(kRoundToMinusInf,
   5054                        result_reg,
   5055                        double_input,
   5056                        scratch1,
   5057                        double_scratch0(),
   5058                        except_flag,
   5059                        kCheckForInexactConversion);
   5060 
   5061     // Deopt if the operation did not succeed (except_flag != 0).
   5062     DeoptimizeIf(ne, instr, except_flag, Operand(zero_reg));
   5063 
   5064     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
   5065       Label done;
   5066       __ Branch(&done, ne, result_reg, Operand(zero_reg));
   5067       __ Mfhc1(scratch1, double_input);
   5068       __ And(scratch1, scratch1, Operand(HeapNumber::kSignMask));
   5069       DeoptimizeIf(ne, instr, scratch1, Operand(zero_reg));
   5070       __ bind(&done);
   5071     }
   5072   }
   5073   __ SmiTagCheckOverflow(result_reg, result_reg, scratch1);
   5074   DeoptimizeIf(lt, instr, scratch1, Operand(zero_reg));
   5075 }
   5076 
   5077 
   5078 void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
   5079   LOperand* input = instr->value();
   5080   __ SmiTst(ToRegister(input), at);
   5081   DeoptimizeIf(ne, instr, at, Operand(zero_reg));
   5082 }
   5083 
   5084 
   5085 void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
   5086   if (!instr->hydrogen()->value()->type().IsHeapObject()) {
   5087     LOperand* input = instr->value();
   5088     __ SmiTst(ToRegister(input), at);
   5089     DeoptimizeIf(eq, instr, at, Operand(zero_reg));
   5090   }
   5091 }
   5092 
   5093 
   5094 void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
   5095   Register input = ToRegister(instr->value());
   5096   Register scratch = scratch0();
   5097 
   5098   __ GetObjectType(input, scratch, scratch);
   5099 
   5100   if (instr->hydrogen()->is_interval_check()) {
   5101     InstanceType first;
   5102     InstanceType last;
   5103     instr->hydrogen()->GetCheckInterval(&first, &last);
   5104 
   5105     // If there is only one type in the interval check for equality.
   5106     if (first == last) {
   5107       DeoptimizeIf(ne, instr, scratch, Operand(first));
   5108     } else {
   5109       DeoptimizeIf(lo, instr, scratch, Operand(first));
   5110       // Omit check for the last type.
   5111       if (last != LAST_TYPE) {
   5112         DeoptimizeIf(hi, instr, scratch, Operand(last));
   5113       }
   5114     }
   5115   } else {
   5116     uint8_t mask;
   5117     uint8_t tag;
   5118     instr->hydrogen()->GetCheckMaskAndTag(&mask, &tag);
   5119 
   5120     if (base::bits::IsPowerOfTwo32(mask)) {
   5121       DCHECK(tag == 0 || base::bits::IsPowerOfTwo32(tag));
   5122       __ And(at, scratch, mask);
   5123       DeoptimizeIf(tag == 0 ? ne : eq, instr, at, Operand(zero_reg));
   5124     } else {
   5125       __ And(scratch, scratch, Operand(mask));
   5126       DeoptimizeIf(ne, instr, scratch, Operand(tag));
   5127     }
   5128   }
   5129 }
   5130 
   5131 
   5132 void LCodeGen::DoCheckValue(LCheckValue* instr) {
   5133   Register reg = ToRegister(instr->value());
   5134   Handle<HeapObject> object = instr->hydrogen()->object().handle();
   5135   AllowDeferredHandleDereference smi_check;
   5136   if (isolate()->heap()->InNewSpace(*object)) {
   5137     Register reg = ToRegister(instr->value());
   5138     Handle<Cell> cell = isolate()->factory()->NewCell(object);
   5139     __ li(at, Operand(Handle<Object>(cell)));
   5140     __ lw(at, FieldMemOperand(at, Cell::kValueOffset));
   5141     DeoptimizeIf(ne, instr, reg, Operand(at));
   5142   } else {
   5143     DeoptimizeIf(ne, instr, reg, Operand(object));
   5144   }
   5145 }
   5146 
   5147 
   5148 void LCodeGen::DoDeferredInstanceMigration(LCheckMaps* instr, Register object) {
   5149   {
   5150     PushSafepointRegistersScope scope(this);
   5151     __ push(object);
   5152     __ mov(cp, zero_reg);
   5153     __ CallRuntimeSaveDoubles(Runtime::kTryMigrateInstance);
   5154     RecordSafepointWithRegisters(
   5155         instr->pointer_map(), 1, Safepoint::kNoLazyDeopt);
   5156     __ StoreToSafepointRegisterSlot(v0, scratch0());
   5157   }
   5158   __ SmiTst(scratch0(), at);
   5159   DeoptimizeIf(eq, instr, at, Operand(zero_reg));
   5160 }
   5161 
   5162 
   5163 void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
   5164   class DeferredCheckMaps FINAL : public LDeferredCode {
   5165    public:
   5166     DeferredCheckMaps(LCodeGen* codegen, LCheckMaps* instr, Register object)
   5167         : LDeferredCode(codegen), instr_(instr), object_(object) {
   5168       SetExit(check_maps());
   5169     }
   5170     virtual void Generate() OVERRIDE {
   5171       codegen()->DoDeferredInstanceMigration(instr_, object_);
   5172     }
   5173     Label* check_maps() { return &check_maps_; }
   5174     virtual LInstruction* instr() OVERRIDE { return instr_; }
   5175    private:
   5176     LCheckMaps* instr_;
   5177     Label check_maps_;
   5178     Register object_;
   5179   };
   5180 
   5181   if (instr->hydrogen()->IsStabilityCheck()) {
   5182     const UniqueSet<Map>* maps = instr->hydrogen()->maps();
   5183     for (int i = 0; i < maps->size(); ++i) {
   5184       AddStabilityDependency(maps->at(i).handle());
   5185     }
   5186     return;
   5187   }
   5188 
   5189   Register map_reg = scratch0();
   5190   LOperand* input = instr->value();
   5191   DCHECK(input->IsRegister());
   5192   Register reg = ToRegister(input);
   5193   __ lw(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
   5194 
   5195   DeferredCheckMaps* deferred = NULL;
   5196   if (instr->hydrogen()->HasMigrationTarget()) {
   5197     deferred = new(zone()) DeferredCheckMaps(this, instr, reg);
   5198     __ bind(deferred->check_maps());
   5199   }
   5200 
   5201   const UniqueSet<Map>* maps = instr->hydrogen()->maps();
   5202   Label success;
   5203   for (int i = 0; i < maps->size() - 1; i++) {
   5204     Handle<Map> map = maps->at(i).handle();
   5205     __ CompareMapAndBranch(map_reg, map, &success, eq, &success);
   5206   }
   5207   Handle<Map> map = maps->at(maps->size() - 1).handle();
   5208   // Do the CompareMap() directly within the Branch() and DeoptimizeIf().
   5209   if (instr->hydrogen()->HasMigrationTarget()) {
   5210     __ Branch(deferred->entry(), ne, map_reg, Operand(map));
   5211   } else {
   5212     DeoptimizeIf(ne, instr, map_reg, Operand(map));
   5213   }
   5214 
   5215   __ bind(&success);
   5216 }
   5217 
   5218 
   5219 void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
   5220   DoubleRegister value_reg = ToDoubleRegister(instr->unclamped());
   5221   Register result_reg = ToRegister(instr->result());
   5222   DoubleRegister temp_reg = ToDoubleRegister(instr->temp());
   5223   __ ClampDoubleToUint8(result_reg, value_reg, temp_reg);
   5224 }
   5225 
   5226 
   5227 void LCodeGen::DoClampIToUint8(LClampIToUint8* instr) {
   5228   Register unclamped_reg = ToRegister(instr->unclamped());
   5229   Register result_reg = ToRegister(instr->result());
   5230   __ ClampUint8(result_reg, unclamped_reg);
   5231 }
   5232 
   5233 
   5234 void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
   5235   Register scratch = scratch0();
   5236   Register input_reg = ToRegister(instr->unclamped());
   5237   Register result_reg = ToRegister(instr->result());
   5238   DoubleRegister temp_reg = ToDoubleRegister(instr->temp());
   5239   Label is_smi, done, heap_number;
   5240 
   5241   // Both smi and heap number cases are handled.
   5242   __ UntagAndJumpIfSmi(scratch, input_reg, &is_smi);
   5243 
   5244   // Check for heap number
   5245   __ lw(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
   5246   __ Branch(&heap_number, eq, scratch, Operand(factory()->heap_number_map()));
   5247 
   5248   // Check for undefined. Undefined is converted to zero for clamping
   5249   // conversions.
   5250   DeoptimizeIf(ne, instr, input_reg, Operand(factory()->undefined_value()));
   5251   __ mov(result_reg, zero_reg);
   5252   __ jmp(&done);
   5253 
   5254   // Heap number
   5255   __ bind(&heap_number);
   5256   __ ldc1(double_scratch0(), FieldMemOperand(input_reg,
   5257                                              HeapNumber::kValueOffset));
   5258   __ ClampDoubleToUint8(result_reg, double_scratch0(), temp_reg);
   5259   __ jmp(&done);
   5260 
   5261   __ bind(&is_smi);
   5262   __ ClampUint8(result_reg, scratch);
   5263 
   5264   __ bind(&done);
   5265 }
   5266 
   5267 
   5268 void LCodeGen::DoDoubleBits(LDoubleBits* instr) {
   5269   DoubleRegister value_reg = ToDoubleRegister(instr->value());
   5270   Register result_reg = ToRegister(instr->result());
   5271   if (instr->hydrogen()->bits() == HDoubleBits::HIGH) {
   5272     __ FmoveHigh(result_reg, value_reg);
   5273   } else {
   5274     __ FmoveLow(result_reg, value_reg);
   5275   }
   5276 }
   5277 
   5278 
   5279 void LCodeGen::DoConstructDouble(LConstructDouble* instr) {
   5280   Register hi_reg = ToRegister(instr->hi());
   5281   Register lo_reg = ToRegister(instr->lo());
   5282   DoubleRegister result_reg = ToDoubleRegister(instr->result());
   5283   __ Move(result_reg, lo_reg, hi_reg);
   5284 }
   5285 
   5286 
   5287 void LCodeGen::DoAllocate(LAllocate* instr) {
   5288   class DeferredAllocate FINAL : public LDeferredCode {
   5289    public:
   5290     DeferredAllocate(LCodeGen* codegen, LAllocate* instr)
   5291         : LDeferredCode(codegen), instr_(instr) { }
   5292     virtual void Generate() OVERRIDE {
   5293       codegen()->DoDeferredAllocate(instr_);
   5294     }
   5295     virtual LInstruction* instr() OVERRIDE { return instr_; }
   5296    private:
   5297     LAllocate* instr_;
   5298   };
   5299 
   5300   DeferredAllocate* deferred =
   5301       new(zone()) DeferredAllocate(this, instr);
   5302 
   5303   Register result = ToRegister(instr->result());
   5304   Register scratch = ToRegister(instr->temp1());
   5305   Register scratch2 = ToRegister(instr->temp2());
   5306 
   5307   // Allocate memory for the object.
   5308   AllocationFlags flags = TAG_OBJECT;
   5309   if (instr->hydrogen()->MustAllocateDoubleAligned()) {
   5310     flags = static_cast<AllocationFlags>(flags | DOUBLE_ALIGNMENT);
   5311   }
   5312   if (instr->hydrogen()->IsOldPointerSpaceAllocation()) {
   5313     DCHECK(!instr->hydrogen()->IsOldDataSpaceAllocation());
   5314     DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
   5315     flags = static_cast<AllocationFlags>(flags | PRETENURE_OLD_POINTER_SPACE);
   5316   } else if (instr->hydrogen()->IsOldDataSpaceAllocation()) {
   5317     DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
   5318     flags = static_cast<AllocationFlags>(flags | PRETENURE_OLD_DATA_SPACE);
   5319   }
   5320   if (instr->size()->IsConstantOperand()) {
   5321     int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
   5322     if (size <= Page::kMaxRegularHeapObjectSize) {
   5323       __ Allocate(size, result, scratch, scratch2, deferred->entry(), flags);
   5324     } else {
   5325       __ jmp(deferred->entry());
   5326     }
   5327   } else {
   5328     Register size = ToRegister(instr->size());
   5329     __ Allocate(size, result, scratch, scratch2, deferred->entry(), flags);
   5330   }
   5331 
   5332   __ bind(deferred->exit());
   5333 
   5334   if (instr->hydrogen()->MustPrefillWithFiller()) {
   5335     STATIC_ASSERT(kHeapObjectTag == 1);
   5336     if (instr->size()->IsConstantOperand()) {
   5337       int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
   5338       __ li(scratch, Operand(size - kHeapObjectTag));
   5339     } else {
   5340       __ Subu(scratch, ToRegister(instr->size()), Operand(kHeapObjectTag));
   5341     }
   5342     __ li(scratch2, Operand(isolate()->factory()->one_pointer_filler_map()));
   5343     Label loop;
   5344     __ bind(&loop);
   5345     __ Subu(scratch, scratch, Operand(kPointerSize));
   5346     __ Addu(at, result, Operand(scratch));
   5347     __ sw(scratch2, MemOperand(at));
   5348     __ Branch(&loop, ge, scratch, Operand(zero_reg));
   5349   }
   5350 }
   5351 
   5352 
   5353 void LCodeGen::DoDeferredAllocate(LAllocate* instr) {
   5354   Register result = ToRegister(instr->result());
   5355 
   5356   // TODO(3095996): Get rid of this. For now, we need to make the
   5357   // result register contain a valid pointer because it is already
   5358   // contained in the register pointer map.
   5359   __ mov(result, zero_reg);
   5360 
   5361   PushSafepointRegistersScope scope(this);
   5362   if (instr->size()->IsRegister()) {
   5363     Register size = ToRegister(instr->size());
   5364     DCHECK(!size.is(result));
   5365     __ SmiTag(size);
   5366     __ push(size);
   5367   } else {
   5368     int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
   5369     if (size >= 0 && size <= Smi::kMaxValue) {
   5370       __ Push(Smi::FromInt(size));
   5371     } else {
   5372       // We should never get here at runtime => abort
   5373       __ stop("invalid allocation size");
   5374       return;
   5375     }
   5376   }
   5377 
   5378   int flags = AllocateDoubleAlignFlag::encode(
   5379       instr->hydrogen()->MustAllocateDoubleAligned());
   5380   if (instr->hydrogen()->IsOldPointerSpaceAllocation()) {
   5381     DCHECK(!instr->hydrogen()->IsOldDataSpaceAllocation());
   5382     DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
   5383     flags = AllocateTargetSpace::update(flags, OLD_POINTER_SPACE);
   5384   } else if (instr->hydrogen()->IsOldDataSpaceAllocation()) {
   5385     DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
   5386     flags = AllocateTargetSpace::update(flags, OLD_DATA_SPACE);
   5387   } else {
   5388     flags = AllocateTargetSpace::update(flags, NEW_SPACE);
   5389   }
   5390   __ Push(Smi::FromInt(flags));
   5391 
   5392   CallRuntimeFromDeferred(
   5393       Runtime::kAllocateInTargetSpace, 2, instr, instr->context());
   5394   __ StoreToSafepointRegisterSlot(v0, result);
   5395 }
   5396 
   5397 
   5398 void LCodeGen::DoToFastProperties(LToFastProperties* instr) {
   5399   DCHECK(ToRegister(instr->value()).is(a0));
   5400   DCHECK(ToRegister(instr->result()).is(v0));
   5401   __ push(a0);
   5402   CallRuntime(Runtime::kToFastProperties, 1, instr);
   5403 }
   5404 
   5405 
   5406 void LCodeGen::DoRegExpLiteral(LRegExpLiteral* instr) {
   5407   DCHECK(ToRegister(instr->context()).is(cp));
   5408   Label materialized;
   5409   // Registers will be used as follows:
   5410   // t3 = literals array.
   5411   // a1 = regexp literal.
   5412   // a0 = regexp literal clone.
   5413   // a2 and t0-t2 are used as temporaries.
   5414   int literal_offset =
   5415       FixedArray::OffsetOfElementAt(instr->hydrogen()->literal_index());
   5416   __ li(t3, instr->hydrogen()->literals());
   5417   __ lw(a1, FieldMemOperand(t3, literal_offset));
   5418   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   5419   __ Branch(&materialized, ne, a1, Operand(at));
   5420 
   5421   // Create regexp literal using runtime function
   5422   // Result will be in v0.
   5423   __ li(t2, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
   5424   __ li(t1, Operand(instr->hydrogen()->pattern()));
   5425   __ li(t0, Operand(instr->hydrogen()->flags()));
   5426   __ Push(t3, t2, t1, t0);
   5427   CallRuntime(Runtime::kMaterializeRegExpLiteral, 4, instr);
   5428   __ mov(a1, v0);
   5429 
   5430   __ bind(&materialized);
   5431   int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
   5432   Label allocated, runtime_allocate;
   5433 
   5434   __ Allocate(size, v0, a2, a3, &runtime_allocate, TAG_OBJECT);
   5435   __ jmp(&allocated);
   5436 
   5437   __ bind(&runtime_allocate);
   5438   __ li(a0, Operand(Smi::FromInt(size)));
   5439   __ Push(a1, a0);
   5440   CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);
   5441   __ pop(a1);
   5442 
   5443   __ bind(&allocated);
   5444   // Copy the content into the newly allocated memory.
   5445   // (Unroll copy loop once for better throughput).
   5446   for (int i = 0; i < size - kPointerSize; i += 2 * kPointerSize) {
   5447     __ lw(a3, FieldMemOperand(a1, i));
   5448     __ lw(a2, FieldMemOperand(a1, i + kPointerSize));
   5449     __ sw(a3, FieldMemOperand(v0, i));
   5450     __ sw(a2, FieldMemOperand(v0, i + kPointerSize));
   5451   }
   5452   if ((size % (2 * kPointerSize)) != 0) {
   5453     __ lw(a3, FieldMemOperand(a1, size - kPointerSize));
   5454     __ sw(a3, FieldMemOperand(v0, size - kPointerSize));
   5455   }
   5456 }
   5457 
   5458 
   5459 void LCodeGen::DoFunctionLiteral(LFunctionLiteral* instr) {
   5460   DCHECK(ToRegister(instr->context()).is(cp));
   5461   // Use the fast case closure allocation code that allocates in new
   5462   // space for nested functions that don't need literals cloning.
   5463   bool pretenure = instr->hydrogen()->pretenure();
   5464   if (!pretenure && instr->hydrogen()->has_no_literals()) {
   5465     FastNewClosureStub stub(isolate(), instr->hydrogen()->strict_mode(),
   5466                             instr->hydrogen()->kind());
   5467     __ li(a2, Operand(instr->hydrogen()->shared_info()));
   5468     CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   5469   } else {
   5470     __ li(a2, Operand(instr->hydrogen()->shared_info()));
   5471     __ li(a1, Operand(pretenure ? factory()->true_value()
   5472                                 : factory()->false_value()));
   5473     __ Push(cp, a2, a1);
   5474     CallRuntime(Runtime::kNewClosure, 3, instr);
   5475   }
   5476 }
   5477 
   5478 
   5479 void LCodeGen::DoTypeof(LTypeof* instr) {
   5480   DCHECK(ToRegister(instr->result()).is(v0));
   5481   Register input = ToRegister(instr->value());
   5482   __ push(input);
   5483   CallRuntime(Runtime::kTypeof, 1, instr);
   5484 }
   5485 
   5486 
   5487 void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
   5488   Register input = ToRegister(instr->value());
   5489 
   5490   Register cmp1 = no_reg;
   5491   Operand cmp2 = Operand(no_reg);
   5492 
   5493   Condition final_branch_condition = EmitTypeofIs(instr->TrueLabel(chunk_),
   5494                                                   instr->FalseLabel(chunk_),
   5495                                                   input,
   5496                                                   instr->type_literal(),
   5497                                                   &cmp1,
   5498                                                   &cmp2);
   5499 
   5500   DCHECK(cmp1.is_valid());
   5501   DCHECK(!cmp2.is_reg() || cmp2.rm().is_valid());
   5502 
   5503   if (final_branch_condition != kNoCondition) {
   5504     EmitBranch(instr, final_branch_condition, cmp1, cmp2);
   5505   }
   5506 }
   5507 
   5508 
   5509 Condition LCodeGen::EmitTypeofIs(Label* true_label,
   5510                                  Label* false_label,
   5511                                  Register input,
   5512                                  Handle<String> type_name,
   5513                                  Register* cmp1,
   5514                                  Operand* cmp2) {
   5515   // This function utilizes the delay slot heavily. This is used to load
   5516   // values that are always usable without depending on the type of the input
   5517   // register.
   5518   Condition final_branch_condition = kNoCondition;
   5519   Register scratch = scratch0();
   5520   Factory* factory = isolate()->factory();
   5521   if (String::Equals(type_name, factory->number_string())) {
   5522     __ JumpIfSmi(input, true_label);
   5523     __ lw(input, FieldMemOperand(input, HeapObject::kMapOffset));
   5524     __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
   5525     *cmp1 = input;
   5526     *cmp2 = Operand(at);
   5527     final_branch_condition = eq;
   5528 
   5529   } else if (String::Equals(type_name, factory->string_string())) {
   5530     __ JumpIfSmi(input, false_label);
   5531     __ GetObjectType(input, input, scratch);
   5532     __ Branch(USE_DELAY_SLOT, false_label,
   5533               ge, scratch, Operand(FIRST_NONSTRING_TYPE));
   5534     // input is an object so we can load the BitFieldOffset even if we take the
   5535     // other branch.
   5536     __ lbu(at, FieldMemOperand(input, Map::kBitFieldOffset));
   5537     __ And(at, at, 1 << Map::kIsUndetectable);
   5538     *cmp1 = at;
   5539     *cmp2 = Operand(zero_reg);
   5540     final_branch_condition = eq;
   5541 
   5542   } else if (String::Equals(type_name, factory->symbol_string())) {
   5543     __ JumpIfSmi(input, false_label);
   5544     __ GetObjectType(input, input, scratch);
   5545     *cmp1 = scratch;
   5546     *cmp2 = Operand(SYMBOL_TYPE);
   5547     final_branch_condition = eq;
   5548 
   5549   } else if (String::Equals(type_name, factory->boolean_string())) {
   5550     __ LoadRoot(at, Heap::kTrueValueRootIndex);
   5551     __ Branch(USE_DELAY_SLOT, true_label, eq, at, Operand(input));
   5552     __ LoadRoot(at, Heap::kFalseValueRootIndex);
   5553     *cmp1 = at;
   5554     *cmp2 = Operand(input);
   5555     final_branch_condition = eq;
   5556 
   5557   } else if (String::Equals(type_name, factory->undefined_string())) {
   5558     __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   5559     __ Branch(USE_DELAY_SLOT, true_label, eq, at, Operand(input));
   5560     // The first instruction of JumpIfSmi is an And - it is safe in the delay
   5561     // slot.
   5562     __ JumpIfSmi(input, false_label);
   5563     // Check for undetectable objects => true.
   5564     __ lw(input, FieldMemOperand(input, HeapObject::kMapOffset));
   5565     __ lbu(at, FieldMemOperand(input, Map::kBitFieldOffset));
   5566     __ And(at, at, 1 << Map::kIsUndetectable);
   5567     *cmp1 = at;
   5568     *cmp2 = Operand(zero_reg);
   5569     final_branch_condition = ne;
   5570 
   5571   } else if (String::Equals(type_name, factory->function_string())) {
   5572     STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
   5573     __ JumpIfSmi(input, false_label);
   5574     __ GetObjectType(input, scratch, input);
   5575     __ Branch(true_label, eq, input, Operand(JS_FUNCTION_TYPE));
   5576     *cmp1 = input;
   5577     *cmp2 = Operand(JS_FUNCTION_PROXY_TYPE);
   5578     final_branch_condition = eq;
   5579 
   5580   } else if (String::Equals(type_name, factory->object_string())) {
   5581     __ JumpIfSmi(input, false_label);
   5582     __ LoadRoot(at, Heap::kNullValueRootIndex);
   5583     __ Branch(USE_DELAY_SLOT, true_label, eq, at, Operand(input));
   5584     Register map = input;
   5585     __ GetObjectType(input, map, scratch);
   5586     __ Branch(false_label,
   5587               lt, scratch, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
   5588     __ Branch(USE_DELAY_SLOT, false_label,
   5589               gt, scratch, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
   5590     // map is still valid, so the BitField can be loaded in delay slot.
   5591     // Check for undetectable objects => false.
   5592     __ lbu(at, FieldMemOperand(map, Map::kBitFieldOffset));
   5593     __ And(at, at, 1 << Map::kIsUndetectable);
   5594     *cmp1 = at;
   5595     *cmp2 = Operand(zero_reg);
   5596     final_branch_condition = eq;
   5597 
   5598   } else {
   5599     *cmp1 = at;
   5600     *cmp2 = Operand(zero_reg);  // Set to valid regs, to avoid caller assertion.
   5601     __ Branch(false_label);
   5602   }
   5603 
   5604   return final_branch_condition;
   5605 }
   5606 
   5607 
   5608 void LCodeGen::DoIsConstructCallAndBranch(LIsConstructCallAndBranch* instr) {
   5609   Register temp1 = ToRegister(instr->temp());
   5610 
   5611   EmitIsConstructCall(temp1, scratch0());
   5612 
   5613   EmitBranch(instr, eq, temp1,
   5614              Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
   5615 }
   5616 
   5617 
   5618 void LCodeGen::EmitIsConstructCall(Register temp1, Register temp2) {
   5619   DCHECK(!temp1.is(temp2));
   5620   // Get the frame pointer for the calling frame.
   5621   __ lw(temp1, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   5622 
   5623   // Skip the arguments adaptor frame if it exists.
   5624   Label check_frame_marker;
   5625   __ lw(temp2, MemOperand(temp1, StandardFrameConstants::kContextOffset));
   5626   __ Branch(&check_frame_marker, ne, temp2,
   5627             Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
   5628   __ lw(temp1, MemOperand(temp1, StandardFrameConstants::kCallerFPOffset));
   5629 
   5630   // Check the marker in the calling frame.
   5631   __ bind(&check_frame_marker);
   5632   __ lw(temp1, MemOperand(temp1, StandardFrameConstants::kMarkerOffset));
   5633 }
   5634 
   5635 
   5636 void LCodeGen::EnsureSpaceForLazyDeopt(int space_needed) {
   5637   if (!info()->IsStub()) {
   5638     // Ensure that we have enough space after the previous lazy-bailout
   5639     // instruction for patching the code here.
   5640     int current_pc = masm()->pc_offset();
   5641     if (current_pc < last_lazy_deopt_pc_ + space_needed) {
   5642       int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
   5643       DCHECK_EQ(0, padding_size % Assembler::kInstrSize);
   5644       while (padding_size > 0) {
   5645         __ nop();
   5646         padding_size -= Assembler::kInstrSize;
   5647       }
   5648     }
   5649   }
   5650   last_lazy_deopt_pc_ = masm()->pc_offset();
   5651 }
   5652 
   5653 
   5654 void LCodeGen::DoLazyBailout(LLazyBailout* instr) {
   5655   last_lazy_deopt_pc_ = masm()->pc_offset();
   5656   DCHECK(instr->HasEnvironment());
   5657   LEnvironment* env = instr->environment();
   5658   RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
   5659   safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
   5660 }
   5661 
   5662 
   5663 void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
   5664   Deoptimizer::BailoutType type = instr->hydrogen()->type();
   5665   // TODO(danno): Stubs expect all deopts to be lazy for historical reasons (the
   5666   // needed return address), even though the implementation of LAZY and EAGER is
   5667   // now identical. When LAZY is eventually completely folded into EAGER, remove
   5668   // the special case below.
   5669   if (info()->IsStub() && type == Deoptimizer::EAGER) {
   5670     type = Deoptimizer::LAZY;
   5671   }
   5672 
   5673   DeoptimizeIf(al, instr, type, zero_reg, Operand(zero_reg),
   5674                instr->hydrogen()->reason());
   5675 }
   5676 
   5677 
   5678 void LCodeGen::DoDummy(LDummy* instr) {
   5679   // Nothing to see here, move on!
   5680 }
   5681 
   5682 
   5683 void LCodeGen::DoDummyUse(LDummyUse* instr) {
   5684   // Nothing to see here, move on!
   5685 }
   5686 
   5687 
   5688 void LCodeGen::DoDeferredStackCheck(LStackCheck* instr) {
   5689   PushSafepointRegistersScope scope(this);
   5690   LoadContextFromDeferred(instr->context());
   5691   __ CallRuntimeSaveDoubles(Runtime::kStackGuard);
   5692   RecordSafepointWithLazyDeopt(
   5693       instr, RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
   5694   DCHECK(instr->HasEnvironment());
   5695   LEnvironment* env = instr->environment();
   5696   safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
   5697 }
   5698 
   5699 
   5700 void LCodeGen::DoStackCheck(LStackCheck* instr) {
   5701   class DeferredStackCheck FINAL : public LDeferredCode {
   5702    public:
   5703     DeferredStackCheck(LCodeGen* codegen, LStackCheck* instr)
   5704         : LDeferredCode(codegen), instr_(instr) { }
   5705     virtual void Generate() OVERRIDE {
   5706       codegen()->DoDeferredStackCheck(instr_);
   5707     }
   5708     virtual LInstruction* instr() OVERRIDE { return instr_; }
   5709    private:
   5710     LStackCheck* instr_;
   5711   };
   5712 
   5713   DCHECK(instr->HasEnvironment());
   5714   LEnvironment* env = instr->environment();
   5715   // There is no LLazyBailout instruction for stack-checks. We have to
   5716   // prepare for lazy deoptimization explicitly here.
   5717   if (instr->hydrogen()->is_function_entry()) {
   5718     // Perform stack overflow check.
   5719     Label done;
   5720     __ LoadRoot(at, Heap::kStackLimitRootIndex);
   5721     __ Branch(&done, hs, sp, Operand(at));
   5722     DCHECK(instr->context()->IsRegister());
   5723     DCHECK(ToRegister(instr->context()).is(cp));
   5724     CallCode(isolate()->builtins()->StackCheck(),
   5725              RelocInfo::CODE_TARGET,
   5726              instr);
   5727     __ bind(&done);
   5728   } else {
   5729     DCHECK(instr->hydrogen()->is_backwards_branch());
   5730     // Perform stack overflow check if this goto needs it before jumping.
   5731     DeferredStackCheck* deferred_stack_check =
   5732         new(zone()) DeferredStackCheck(this, instr);
   5733     __ LoadRoot(at, Heap::kStackLimitRootIndex);
   5734     __ Branch(deferred_stack_check->entry(), lo, sp, Operand(at));
   5735     EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
   5736     __ bind(instr->done_label());
   5737     deferred_stack_check->SetExit(instr->done_label());
   5738     RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
   5739     // Don't record a deoptimization index for the safepoint here.
   5740     // This will be done explicitly when emitting call and the safepoint in
   5741     // the deferred code.
   5742   }
   5743 }
   5744 
   5745 
   5746 void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
   5747   // This is a pseudo-instruction that ensures that the environment here is
   5748   // properly registered for deoptimization and records the assembler's PC
   5749   // offset.
   5750   LEnvironment* environment = instr->environment();
   5751 
   5752   // If the environment were already registered, we would have no way of
   5753   // backpatching it with the spill slot operands.
   5754   DCHECK(!environment->HasBeenRegistered());
   5755   RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
   5756 
   5757   GenerateOsrPrologue();
   5758 }
   5759 
   5760 
   5761 void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
   5762   Register result = ToRegister(instr->result());
   5763   Register object = ToRegister(instr->object());
   5764   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   5765   DeoptimizeIf(eq, instr, object, Operand(at));
   5766 
   5767   Register null_value = t1;
   5768   __ LoadRoot(null_value, Heap::kNullValueRootIndex);
   5769   DeoptimizeIf(eq, instr, object, Operand(null_value));
   5770 
   5771   __ And(at, object, kSmiTagMask);
   5772   DeoptimizeIf(eq, instr, at, Operand(zero_reg));
   5773 
   5774   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   5775   __ GetObjectType(object, a1, a1);
   5776   DeoptimizeIf(le, instr, a1, Operand(LAST_JS_PROXY_TYPE));
   5777 
   5778   Label use_cache, call_runtime;
   5779   DCHECK(object.is(a0));
   5780   __ CheckEnumCache(null_value, &call_runtime);
   5781 
   5782   __ lw(result, FieldMemOperand(object, HeapObject::kMapOffset));
   5783   __ Branch(&use_cache);
   5784 
   5785   // Get the set of properties to enumerate.
   5786   __ bind(&call_runtime);
   5787   __ push(object);
   5788   CallRuntime(Runtime::kGetPropertyNamesFast, 1, instr);
   5789 
   5790   __ lw(a1, FieldMemOperand(v0, HeapObject::kMapOffset));
   5791   DCHECK(result.is(v0));
   5792   __ LoadRoot(at, Heap::kMetaMapRootIndex);
   5793   DeoptimizeIf(ne, instr, a1, Operand(at));
   5794   __ bind(&use_cache);
   5795 }
   5796 
   5797 
   5798 void LCodeGen::DoForInCacheArray(LForInCacheArray* instr) {
   5799   Register map = ToRegister(instr->map());
   5800   Register result = ToRegister(instr->result());
   5801   Label load_cache, done;
   5802   __ EnumLength(result, map);
   5803   __ Branch(&load_cache, ne, result, Operand(Smi::FromInt(0)));
   5804   __ li(result, Operand(isolate()->factory()->empty_fixed_array()));
   5805   __ jmp(&done);
   5806 
   5807   __ bind(&load_cache);
   5808   __ LoadInstanceDescriptors(map, result);
   5809   __ lw(result,
   5810         FieldMemOperand(result, DescriptorArray::kEnumCacheOffset));
   5811   __ lw(result,
   5812         FieldMemOperand(result, FixedArray::SizeFor(instr->idx())));
   5813   DeoptimizeIf(eq, instr, result, Operand(zero_reg));
   5814 
   5815   __ bind(&done);
   5816 }
   5817 
   5818 
   5819 void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
   5820   Register object = ToRegister(instr->value());
   5821   Register map = ToRegister(instr->map());
   5822   __ lw(scratch0(), FieldMemOperand(object, HeapObject::kMapOffset));
   5823   DeoptimizeIf(ne, instr, map, Operand(scratch0()));
   5824 }
   5825 
   5826 
   5827 void LCodeGen::DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
   5828                                            Register result,
   5829                                            Register object,
   5830                                            Register index) {
   5831   PushSafepointRegistersScope scope(this);
   5832   __ Push(object, index);
   5833   __ mov(cp, zero_reg);
   5834   __ CallRuntimeSaveDoubles(Runtime::kLoadMutableDouble);
   5835   RecordSafepointWithRegisters(
   5836      instr->pointer_map(), 2, Safepoint::kNoLazyDeopt);
   5837   __ StoreToSafepointRegisterSlot(v0, result);
   5838 }
   5839 
   5840 
   5841 void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
   5842   class DeferredLoadMutableDouble FINAL : public LDeferredCode {
   5843    public:
   5844     DeferredLoadMutableDouble(LCodeGen* codegen,
   5845                               LLoadFieldByIndex* instr,
   5846                               Register result,
   5847                               Register object,
   5848                               Register index)
   5849         : LDeferredCode(codegen),
   5850           instr_(instr),
   5851           result_(result),
   5852           object_(object),
   5853           index_(index) {
   5854     }
   5855     virtual void Generate() OVERRIDE {
   5856       codegen()->DoDeferredLoadMutableDouble(instr_, result_, object_, index_);
   5857     }
   5858     virtual LInstruction* instr() OVERRIDE { return instr_; }
   5859    private:
   5860     LLoadFieldByIndex* instr_;
   5861     Register result_;
   5862     Register object_;
   5863     Register index_;
   5864   };
   5865 
   5866   Register object = ToRegister(instr->object());
   5867   Register index = ToRegister(instr->index());
   5868   Register result = ToRegister(instr->result());
   5869   Register scratch = scratch0();
   5870 
   5871   DeferredLoadMutableDouble* deferred;
   5872   deferred = new(zone()) DeferredLoadMutableDouble(
   5873       this, instr, result, object, index);
   5874 
   5875   Label out_of_object, done;
   5876 
   5877   __ And(scratch, index, Operand(Smi::FromInt(1)));
   5878   __ Branch(deferred->entry(), ne, scratch, Operand(zero_reg));
   5879   __ sra(index, index, 1);
   5880 
   5881   __ Branch(USE_DELAY_SLOT, &out_of_object, lt, index, Operand(zero_reg));
   5882   __ sll(scratch, index, kPointerSizeLog2 - kSmiTagSize);  // In delay slot.
   5883 
   5884   STATIC_ASSERT(kPointerSizeLog2 > kSmiTagSize);
   5885   __ Addu(scratch, object, scratch);
   5886   __ lw(result, FieldMemOperand(scratch, JSObject::kHeaderSize));
   5887 
   5888   __ Branch(&done);
   5889 
   5890   __ bind(&out_of_object);
   5891   __ lw(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
   5892   // Index is equal to negated out of object property index plus 1.
   5893   __ Subu(scratch, result, scratch);
   5894   __ lw(result, FieldMemOperand(scratch,
   5895                                 FixedArray::kHeaderSize - kPointerSize));
   5896   __ bind(deferred->exit());
   5897   __ bind(&done);
   5898 }
   5899 
   5900 
   5901 void LCodeGen::DoStoreFrameContext(LStoreFrameContext* instr) {
   5902   Register context = ToRegister(instr->context());
   5903   __ sw(context, MemOperand(fp, StandardFrameConstants::kContextOffset));
   5904 }
   5905 
   5906 
   5907 void LCodeGen::DoAllocateBlockContext(LAllocateBlockContext* instr) {
   5908   Handle<ScopeInfo> scope_info = instr->scope_info();
   5909   __ li(at, scope_info);
   5910   __ Push(at, ToRegister(instr->function()));
   5911   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   5912   RecordSafepoint(Safepoint::kNoLazyDeopt);
   5913 }
   5914 
   5915 
   5916 #undef __
   5917 
   5918 } }  // namespace v8::internal
   5919