text: // Copyright 2014 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "src/crankshaft/ppc/lithium-codegen-ppc.h"
  
  #include "src/base/bits.h"
  #include "src/code-factory.h"
  #include "src/code-stubs.h"
  #include "src/crankshaft/hydrogen-osr.h"
  #include "src/crankshaft/ppc/lithium-gap-resolver-ppc.h"
  #include "src/ic/ic.h"
  #include "src/ic/stub-cache.h"
  #include "src/profiler/cpu-profiler.h"
  
  namespace v8 {
  namespace internal {
  
  
  class SafepointGenerator final : public CallWrapper {
   public:
    SafepointGenerator(LCodeGen* codegen, LPointerMap* pointers,
                       Safepoint::DeoptMode mode)
        : codegen_(codegen), pointers_(pointers), deopt_mode_(mode) {}
    virtual ~SafepointGenerator() {}
  
    void BeforeCall(int call_size) const override {}
  
    void AfterCall() const override {
      codegen_->RecordSafepoint(pointers_, deopt_mode_);
    }
  
   private:
    LCodeGen* codegen_;
    LPointerMap* pointers_;
    Safepoint::DeoptMode deopt_mode_;
  };
  
  
  #define __ masm()->
  
  bool LCodeGen::GenerateCode() {
    LPhase phase("Z_Code generation", chunk());
    DCHECK(is_unused());
    status_ = GENERATING;
  
    // Open a frame scope to indicate that there is a frame on the stack.  The
    // NONE indicates that the scope shouldn't actually generate code to set up
    // the frame (that is done in GeneratePrologue).
    FrameScope frame_scope(masm_, StackFrame::NONE);
  
    bool rc = GeneratePrologue() && GenerateBody() && GenerateDeferredCode() &&
              GenerateJumpTable() && GenerateSafepointTable();
    if (FLAG_enable_embedded_constant_pool && !rc) {
      masm()->AbortConstantPoolBuilding();
    }
    return rc;
  }
  
  
  void LCodeGen::FinishCode(Handle<Code> code) {
    DCHECK(is_done());
    code->set_stack_slots(GetStackSlotCount());
    code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
    PopulateDeoptimizationData(code);
  }
  
  
  void LCodeGen::SaveCallerDoubles() {
    DCHECK(info()->saves_caller_doubles());
    DCHECK(NeedsEagerFrame());
    Comment(";;; Save clobbered callee double registers");
    int count = 0;
    BitVector* doubles = chunk()->allocated_double_registers();
    BitVector::Iterator save_iterator(doubles);
    while (!save_iterator.Done()) {
      __ stfd(DoubleRegister::from_code(save_iterator.Current()),
              MemOperand(sp, count * kDoubleSize));
      save_iterator.Advance();
      count++;
    }
  }
  
  
  void LCodeGen::RestoreCallerDoubles() {
    DCHECK(info()->saves_caller_doubles());
    DCHECK(NeedsEagerFrame());
    Comment(";;; Restore clobbered callee double registers");
    BitVector* doubles = chunk()->allocated_double_registers();
    BitVector::Iterator save_iterator(doubles);
    int count = 0;
    while (!save_iterator.Done()) {
      __ lfd(DoubleRegister::from_code(save_iterator.Current()),
             MemOperand(sp, count * kDoubleSize));
      save_iterator.Advance();
      count++;
    }
  }
  
  
  bool LCodeGen::GeneratePrologue() {
    DCHECK(is_generating());
  
    if (info()->IsOptimizing()) {
      ProfileEntryHookStub::MaybeCallEntryHook(masm_);
  
  #ifdef DEBUG
      if (strlen(FLAG_stop_at) > 0 &&
          info_->literal()->name()->IsUtf8EqualTo(CStrVector(FLAG_stop_at))) {
        __ stop("stop_at");
      }
  #endif
  
      // r4: Callee's JS function.
      // cp: Callee's context.
      // pp: Callee's constant pool pointer (if enabled)
      // fp: Caller's frame pointer.
      // lr: Caller's pc.
      // ip: Our own function entry (required by the prologue)
    }
  
    int prologue_offset = masm_->pc_offset();
  
    if (prologue_offset) {
      // Prologue logic requires it's starting address in ip and the
      // corresponding offset from the function entry.
      prologue_offset += Instruction::kInstrSize;
      __ addi(ip, ip, Operand(prologue_offset));
    }
    info()->set_prologue_offset(prologue_offset);
    if (NeedsEagerFrame()) {
      if (info()->IsStub()) {
        __ StubPrologue(ip, prologue_offset);
      } else {
        __ Prologue(info()->GeneratePreagedPrologue(), ip, prologue_offset);
      }
      frame_is_built_ = true;
    }
  
    // Reserve space for the stack slots needed by the code.
    int slots = GetStackSlotCount();
    if (slots > 0) {
      __ subi(sp, sp, Operand(slots * kPointerSize));
      if (FLAG_debug_code) {
        __ Push(r3, r4);
        __ li(r0, Operand(slots));
        __ mtctr(r0);
        __ addi(r3, sp, Operand((slots + 2) * kPointerSize));
        __ mov(r4, Operand(kSlotsZapValue));
        Label loop;
        __ bind(&loop);
        __ StorePU(r4, MemOperand(r3, -kPointerSize));
        __ bdnz(&loop);
        __ Pop(r3, r4);
      }
    }
  
    if (info()->saves_caller_doubles()) {
      SaveCallerDoubles();
    }
    return !is_aborted();
  }
  
  
  void LCodeGen::DoPrologue(LPrologue* instr) {
    Comment(";;; Prologue begin");
  
    // Possibly allocate a local context.
    if (info()->scope()->num_heap_slots() > 0) {
      Comment(";;; Allocate local context");
      bool need_write_barrier = true;
      // Argument to NewContext is the function, which is in r4.
      int slots = info()->scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
      Safepoint::DeoptMode deopt_mode = Safepoint::kNoLazyDeopt;
      if (info()->scope()->is_script_scope()) {
        __ push(r4);
        __ Push(info()->scope()->GetScopeInfo(info()->isolate()));
        __ CallRuntime(Runtime::kNewScriptContext);
        deopt_mode = Safepoint::kLazyDeopt;
      } else if (slots <= FastNewContextStub::kMaximumSlots) {
        FastNewContextStub stub(isolate(), slots);
        __ CallStub(&stub);
        // Result of FastNewContextStub is always in new space.
        need_write_barrier = false;
      } else {
        __ push(r4);
        __ CallRuntime(Runtime::kNewFunctionContext);
      }
      RecordSafepoint(deopt_mode);
  
      // Context is returned in both r3 and cp.  It replaces the context
      // passed to us.  It's saved in the stack and kept live in cp.
      __ mr(cp, r3);
      __ StoreP(r3, MemOperand(fp, StandardFrameConstants::kContextOffset));
      // Copy any necessary parameters into the context.
      int num_parameters = scope()->num_parameters();
      int first_parameter = scope()->has_this_declaration() ? -1 : 0;
      for (int i = first_parameter; i < num_parameters; i++) {
        Variable* var = (i == -1) ? scope()->receiver() : scope()->parameter(i);
        if (var->IsContextSlot()) {
          int parameter_offset = StandardFrameConstants::kCallerSPOffset +
                                 (num_parameters - 1 - i) * kPointerSize;
          // Load parameter from stack.
          __ LoadP(r3, MemOperand(fp, parameter_offset));
          // Store it in the context.
          MemOperand target = ContextMemOperand(cp, var->index());
          __ StoreP(r3, target, r0);
          // Update the write barrier. This clobbers r6 and r3.
          if (need_write_barrier) {
            __ RecordWriteContextSlot(cp, target.offset(), r3, r6,
                                      GetLinkRegisterState(), kSaveFPRegs);
          } else if (FLAG_debug_code) {
            Label done;
            __ JumpIfInNewSpace(cp, r3, &done);
            __ Abort(kExpectedNewSpaceObject);
            __ bind(&done);
          }
        }
      }
      Comment(";;; End allocate local context");
    }
  
    Comment(";;; Prologue end");
  }
  
  
  void LCodeGen::GenerateOsrPrologue() {
    // Generate the OSR entry prologue at the first unknown OSR value, or if there
    // are none, at the OSR entrypoint instruction.
    if (osr_pc_offset_ >= 0) return;
  
    osr_pc_offset_ = masm()->pc_offset();
  
    // Adjust the frame size, subsuming the unoptimized frame into the
    // optimized frame.
    int slots = GetStackSlotCount() - graph()->osr()->UnoptimizedFrameSlots();
    DCHECK(slots >= 0);
    __ subi(sp, sp, Operand(slots * kPointerSize));
  }
  
  
  void LCodeGen::GenerateBodyInstructionPre(LInstruction* instr) {
    if (instr->IsCall()) {
      EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
    }
    if (!instr->IsLazyBailout() && !instr->IsGap()) {
      safepoints_.BumpLastLazySafepointIndex();
    }
  }
  
  
  bool LCodeGen::GenerateDeferredCode() {
    DCHECK(is_generating());
    if (deferred_.length() > 0) {
      for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
        LDeferredCode* code = deferred_[i];
  
        HValue* value =
            instructions_->at(code->instruction_index())->hydrogen_value();
        RecordAndWritePosition(
            chunk()->graph()->SourcePositionToScriptPosition(value->position()));
  
        Comment(
            ";;; <@%d,#%d> "
            "-------------------- Deferred %s --------------------",
            code->instruction_index(), code->instr()->hydrogen_value()->id(),
            code->instr()->Mnemonic());
        __ bind(code->entry());
        if (NeedsDeferredFrame()) {
          Comment(";;; Build frame");
          DCHECK(!frame_is_built_);
          DCHECK(info()->IsStub());
          frame_is_built_ = true;
          __ LoadSmiLiteral(scratch0(), Smi::FromInt(StackFrame::STUB));
          __ PushFixedFrame(scratch0());
          __ addi(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
          Comment(";;; Deferred code");
        }
        code->Generate();
        if (NeedsDeferredFrame()) {
          Comment(";;; Destroy frame");
          DCHECK(frame_is_built_);
          __ PopFixedFrame(ip);
          frame_is_built_ = false;
        }
        __ b(code->exit());
      }
    }
  
    return !is_aborted();
  }
  
  
  bool LCodeGen::GenerateJumpTable() {
    // Check that the jump table is accessible from everywhere in the function
    // code, i.e. that offsets to the table can be encoded in the 24bit signed
    // immediate of a branch instruction.
    // To simplify we consider the code size from the first instruction to the
    // end of the jump table. We also don't consider the pc load delta.
    // Each entry in the jump table generates one instruction and inlines one
    // 32bit data after it.
    if (!is_int24((masm()->pc_offset() / Assembler::kInstrSize) +
                  jump_table_.length() * 7)) {
      Abort(kGeneratedCodeIsTooLarge);
    }
  
    if (jump_table_.length() > 0) {
      Label needs_frame, call_deopt_entry;
  
      Comment(";;; -------------------- Jump table --------------------");
      Address base = jump_table_[0].address;
  
      Register entry_offset = scratch0();
  
      int length = jump_table_.length();
      for (int i = 0; i < length; i++) {
        Deoptimizer::JumpTableEntry* table_entry = &jump_table_[i];
        __ bind(&table_entry->label);
  
        DCHECK_EQ(jump_table_[0].bailout_type, table_entry->bailout_type);
        Address entry = table_entry->address;
        DeoptComment(table_entry->deopt_info);
  
        // Second-level deopt table entries are contiguous and small, so instead
        // of loading the full, absolute address of each one, load an immediate
        // offset which will be added to the base address later.
        __ mov(entry_offset, Operand(entry - base));
  
        if (table_entry->needs_frame) {
          DCHECK(!info()->saves_caller_doubles());
          Comment(";;; call deopt with frame");
          __ PushFixedFrame();
          __ b(&needs_frame, SetLK);
        } else {
          __ b(&call_deopt_entry, SetLK);
        }
        info()->LogDeoptCallPosition(masm()->pc_offset(),
                                     table_entry->deopt_info.inlining_id);
      }
  
      if (needs_frame.is_linked()) {
        __ bind(&needs_frame);
        // This variant of deopt can only be used with stubs. Since we don't
        // have a function pointer to install in the stack frame that we're
        // building, install a special marker there instead.
        DCHECK(info()->IsStub());
        __ LoadSmiLiteral(ip, Smi::FromInt(StackFrame::STUB));
        __ push(ip);
        __ addi(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
      }
  
      Comment(";;; call deopt");
      __ bind(&call_deopt_entry);
  
      if (info()->saves_caller_doubles()) {
        DCHECK(info()->IsStub());
        RestoreCallerDoubles();
      }
  
      // Add the base address to the offset previously loaded in entry_offset.
      __ mov(ip, Operand(ExternalReference::ForDeoptEntry(base)));
      __ add(ip, entry_offset, ip);
      __ Jump(ip);
    }
  
    // The deoptimization jump table is the last part of the instruction
    // sequence. Mark the generated code as done unless we bailed out.
    if (!is_aborted()) status_ = DONE;
    return !is_aborted();
  }
  
  
  bool LCodeGen::GenerateSafepointTable() {
    DCHECK(is_done());
    safepoints_.Emit(masm(), GetStackSlotCount());
    return !is_aborted();
  }
  
  
  Register LCodeGen::ToRegister(int code) const {
    return Register::from_code(code);
  }
  
  
  DoubleRegister LCodeGen::ToDoubleRegister(int code) const {
    return DoubleRegister::from_code(code);
  }
  
  
  Register LCodeGen::ToRegister(LOperand* op) const {
    DCHECK(op->IsRegister());
    return ToRegister(op->index());
  }
  
  
  Register LCodeGen::EmitLoadRegister(LOperand* op, Register scratch) {
    if (op->IsRegister()) {
      return ToRegister(op->index());
    } else if (op->IsConstantOperand()) {
      LConstantOperand* const_op = LConstantOperand::cast(op);
      HConstant* constant = chunk_->LookupConstant(const_op);
      Handle<Object> literal = constant->handle(isolate());
      Representation r = chunk_->LookupLiteralRepresentation(const_op);
      if (r.IsInteger32()) {
        AllowDeferredHandleDereference get_number;
        DCHECK(literal->IsNumber());
        __ LoadIntLiteral(scratch, static_cast<int32_t>(literal->Number()));
      } else if (r.IsDouble()) {
        Abort(kEmitLoadRegisterUnsupportedDoubleImmediate);
      } else {
        DCHECK(r.IsSmiOrTagged());
        __ Move(scratch, literal);
      }
      return scratch;
    } else if (op->IsStackSlot()) {
      __ LoadP(scratch, ToMemOperand(op));
      return scratch;
    }
    UNREACHABLE();
    return scratch;
  }
  
  
  void LCodeGen::EmitLoadIntegerConstant(LConstantOperand* const_op,
                                         Register dst) {
    DCHECK(IsInteger32(const_op));
    HConstant* constant = chunk_->LookupConstant(const_op);
    int32_t value = constant->Integer32Value();
    if (IsSmi(const_op)) {
      __ LoadSmiLiteral(dst, Smi::FromInt(value));
    } else {
      __ LoadIntLiteral(dst, value);
    }
  }
  
  
  DoubleRegister LCodeGen::ToDoubleRegister(LOperand* op) const {
    DCHECK(op->IsDoubleRegister());
    return ToDoubleRegister(op->index());
  }
  
  
  Handle<Object> LCodeGen::ToHandle(LConstantOperand* op) const {
    HConstant* constant = chunk_->LookupConstant(op);
    DCHECK(chunk_->LookupLiteralRepresentation(op).IsSmiOrTagged());
    return constant->handle(isolate());
  }
  
  
  bool LCodeGen::IsInteger32(LConstantOperand* op) const {
    return chunk_->LookupLiteralRepresentation(op).IsSmiOrInteger32();
  }
  
  
  bool LCodeGen::IsSmi(LConstantOperand* op) const {
    return chunk_->LookupLiteralRepresentation(op).IsSmi();
  }
  
  
  int32_t LCodeGen::ToInteger32(LConstantOperand* op) const {
    return ToRepresentation(op, Representation::Integer32());
  }
  
  
  intptr_t LCodeGen::ToRepresentation(LConstantOperand* op,
                                      const Representation& r) const {
    HConstant* constant = chunk_->LookupConstant(op);
    int32_t value = constant->Integer32Value();
    if (r.IsInteger32()) return value;
    DCHECK(r.IsSmiOrTagged());
    return reinterpret_cast<intptr_t>(Smi::FromInt(value));
  }
  
  
  Smi* LCodeGen::ToSmi(LConstantOperand* op) const {
    HConstant* constant = chunk_->LookupConstant(op);
    return Smi::FromInt(constant->Integer32Value());
  }
  
  
  double LCodeGen::ToDouble(LConstantOperand* op) const {
    HConstant* constant = chunk_->LookupConstant(op);
    DCHECK(constant->HasDoubleValue());
    return constant->DoubleValue();
  }
  
  
  Operand LCodeGen::ToOperand(LOperand* op) {
    if (op->IsConstantOperand()) {
      LConstantOperand* const_op = LConstantOperand::cast(op);
      HConstant* constant = chunk()->LookupConstant(const_op);
      Representation r = chunk_->LookupLiteralRepresentation(const_op);
      if (r.IsSmi()) {
        DCHECK(constant->HasSmiValue());
        return Operand(Smi::FromInt(constant->Integer32Value()));
      } else if (r.IsInteger32()) {
        DCHECK(constant->HasInteger32Value());
        return Operand(constant->Integer32Value());
      } else if (r.IsDouble()) {
        Abort(kToOperandUnsupportedDoubleImmediate);
      }
      DCHECK(r.IsTagged());
      return Operand(constant->handle(isolate()));
    } else if (op->IsRegister()) {
      return Operand(ToRegister(op));
    } else if (op->IsDoubleRegister()) {
      Abort(kToOperandIsDoubleRegisterUnimplemented);
      return Operand::Zero();
    }
    // Stack slots not implemented, use ToMemOperand instead.
    UNREACHABLE();
    return Operand::Zero();
  }
  
  
  static int ArgumentsOffsetWithoutFrame(int index) {
    DCHECK(index < 0);
    return -(index + 1) * kPointerSize;
  }
  
  
  MemOperand LCodeGen::ToMemOperand(LOperand* op) const {
    DCHECK(!op->IsRegister());
    DCHECK(!op->IsDoubleRegister());
    DCHECK(op->IsStackSlot() || op->IsDoubleStackSlot());
    if (NeedsEagerFrame()) {
      return MemOperand(fp, StackSlotOffset(op->index()));
    } else {
      // Retrieve parameter without eager stack-frame relative to the
      // stack-pointer.
      return MemOperand(sp, ArgumentsOffsetWithoutFrame(op->index()));
    }
  }
  
  
  MemOperand LCodeGen::ToHighMemOperand(LOperand* op) const {
    DCHECK(op->IsDoubleStackSlot());
    if (NeedsEagerFrame()) {
      return MemOperand(fp, StackSlotOffset(op->index()) + kPointerSize);
    } else {
      // Retrieve parameter without eager stack-frame relative to the
      // stack-pointer.
      return MemOperand(sp,
                        ArgumentsOffsetWithoutFrame(op->index()) + kPointerSize);
    }
  }
  
  
  void LCodeGen::WriteTranslation(LEnvironment* environment,
                                  Translation* translation) {
    if (environment == NULL) return;
  
    // The translation includes one command per value in the environment.
    int translation_size = environment->translation_size();
  
    WriteTranslation(environment->outer(), translation);
    WriteTranslationFrame(environment, translation);
  
    int object_index = 0;
    int dematerialized_index = 0;
    for (int i = 0; i < translation_size; ++i) {
      LOperand* value = environment->values()->at(i);
      AddToTranslation(
          environment, translation, value, environment->HasTaggedValueAt(i),
          environment->HasUint32ValueAt(i), &object_index, &dematerialized_index);
    }
  }
  
  
  void LCodeGen::AddToTranslation(LEnvironment* environment,
                                  Translation* translation, LOperand* op,
                                  bool is_tagged, bool is_uint32,
                                  int* object_index_pointer,
                                  int* dematerialized_index_pointer) {
    if (op == LEnvironment::materialization_marker()) {
      int object_index = (*object_index_pointer)++;
      if (environment->ObjectIsDuplicateAt(object_index)) {
        int dupe_of = environment->ObjectDuplicateOfAt(object_index);
        translation->DuplicateObject(dupe_of);
        return;
      }
      int object_length = environment->ObjectLengthAt(object_index);
      if (environment->ObjectIsArgumentsAt(object_index)) {
        translation->BeginArgumentsObject(object_length);
      } else {
        translation->BeginCapturedObject(object_length);
      }
      int dematerialized_index = *dematerialized_index_pointer;
      int env_offset = environment->translation_size() + dematerialized_index;
      *dematerialized_index_pointer += object_length;
      for (int i = 0; i < object_length; ++i) {
        LOperand* value = environment->values()->at(env_offset + i);
        AddToTranslation(environment, translation, value,
                         environment->HasTaggedValueAt(env_offset + i),
                         environment->HasUint32ValueAt(env_offset + i),
                         object_index_pointer, dematerialized_index_pointer);
      }
      return;
    }
  
    if (op->IsStackSlot()) {
      int index = op->index();
      if (index >= 0) {
        index += StandardFrameConstants::kFixedFrameSize / kPointerSize;
      }
      if (is_tagged) {
        translation->StoreStackSlot(index);
      } else if (is_uint32) {
        translation->StoreUint32StackSlot(index);
      } else {
        translation->StoreInt32StackSlot(index);
      }
    } else if (op->IsDoubleStackSlot()) {
      int index = op->index();
      if (index >= 0) {
        index += StandardFrameConstants::kFixedFrameSize / kPointerSize;
      }
      translation->StoreDoubleStackSlot(index);
    } else if (op->IsRegister()) {
      Register reg = ToRegister(op);
      if (is_tagged) {
        translation->StoreRegister(reg);
      } else if (is_uint32) {
        translation->StoreUint32Register(reg);
      } else {
        translation->StoreInt32Register(reg);
      }
    } else if (op->IsDoubleRegister()) {
      DoubleRegister reg = ToDoubleRegister(op);
      translation->StoreDoubleRegister(reg);
    } else if (op->IsConstantOperand()) {
      HConstant* constant = chunk()->LookupConstant(LConstantOperand::cast(op));
      int src_index = DefineDeoptimizationLiteral(constant->handle(isolate()));
      translation->StoreLiteral(src_index);
    } else {
      UNREACHABLE();
    }
  }
  
  
  void LCodeGen::CallCode(Handle<Code> code, RelocInfo::Mode mode,
                          LInstruction* instr) {
    CallCodeGeneric(code, mode, instr, RECORD_SIMPLE_SAFEPOINT);
  }
  
  
  void LCodeGen::CallCodeGeneric(Handle<Code> code, RelocInfo::Mode mode,
                                 LInstruction* instr,
                                 SafepointMode safepoint_mode) {
    DCHECK(instr != NULL);
    __ Call(code, mode);
    RecordSafepointWithLazyDeopt(instr, safepoint_mode);
  
    // Signal that we don't inline smi code before these stubs in the
    // optimizing code generator.
    if (code->kind() == Code::BINARY_OP_IC || code->kind() == Code::COMPARE_IC) {
      __ nop();
    }
  }
  
  
  void LCodeGen::CallRuntime(const Runtime::Function* function, int num_arguments,
                             LInstruction* instr, SaveFPRegsMode save_doubles) {
    DCHECK(instr != NULL);
  
    __ CallRuntime(function, num_arguments, save_doubles);
  
    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
  }
  
  
  void LCodeGen::LoadContextFromDeferred(LOperand* context) {
    if (context->IsRegister()) {
      __ Move(cp, ToRegister(context));
    } else if (context->IsStackSlot()) {
      __ LoadP(cp, ToMemOperand(context));
    } else if (context->IsConstantOperand()) {
      HConstant* constant =
          chunk_->LookupConstant(LConstantOperand::cast(context));
      __ Move(cp, Handle<Object>::cast(constant->handle(isolate())));
    } else {
      UNREACHABLE();
    }
  }
  
  
  void LCodeGen::CallRuntimeFromDeferred(Runtime::FunctionId id, int argc,
                                         LInstruction* instr, LOperand* context) {
    LoadContextFromDeferred(context);
    __ CallRuntimeSaveDoubles(id);
    RecordSafepointWithRegisters(instr->pointer_map(), argc,
                                 Safepoint::kNoLazyDeopt);
  }
  
  
  void LCodeGen::RegisterEnvironmentForDeoptimization(LEnvironment* environment,
                                                      Safepoint::DeoptMode mode) {
    environment->set_has_been_used();
    if (!environment->HasBeenRegistered()) {
      // Physical stack frame layout:
      // -x ............. -4  0 ..................................... y
      // [incoming arguments] [spill slots] [pushed outgoing arguments]
  
      // Layout of the environment:
      // 0 ..................................................... size-1
      // [parameters] [locals] [expression stack including arguments]
  
      // Layout of the translation:
      // 0 ........................................................ size - 1 + 4
      // [expression stack including arguments] [locals] [4 words] [parameters]
      // |>------------  translation_size ------------<|
  
      int frame_count = 0;
      int jsframe_count = 0;
      for (LEnvironment* e = environment; e != NULL; e = e->outer()) {
        ++frame_count;
        if (e->frame_type() == JS_FUNCTION) {
          ++jsframe_count;
        }
      }
      Translation translation(&translations_, frame_count, jsframe_count, zone());
      WriteTranslation(environment, &translation);
      int deoptimization_index = deoptimizations_.length();
      int pc_offset = masm()->pc_offset();
      environment->Register(deoptimization_index, translation.index(),
                            (mode == Safepoint::kLazyDeopt) ? pc_offset : -1);
      deoptimizations_.Add(environment, zone());
    }
  }
  
  
  void LCodeGen::DeoptimizeIf(Condition cond, LInstruction* instr,
                              Deoptimizer::DeoptReason deopt_reason,
                              Deoptimizer::BailoutType bailout_type,
                              CRegister cr) {
    LEnvironment* environment = instr->environment();
    RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
    DCHECK(environment->HasBeenRegistered());
    int id = environment->deoptimization_index();
    Address entry =
        Deoptimizer::GetDeoptimizationEntry(isolate(), id, bailout_type);
    if (entry == NULL) {
      Abort(kBailoutWasNotPrepared);
      return;
    }
  
    if (FLAG_deopt_every_n_times != 0 && !info()->IsStub()) {
      CRegister alt_cr = cr6;
      Register scratch = scratch0();
      ExternalReference count = ExternalReference::stress_deopt_count(isolate());
      Label no_deopt;
      DCHECK(!alt_cr.is(cr));
      __ Push(r4, scratch);
      __ mov(scratch, Operand(count));
      __ lwz(r4, MemOperand(scratch));
      __ subi(r4, r4, Operand(1));
      __ cmpi(r4, Operand::Zero(), alt_cr);
      __ bne(&no_deopt, alt_cr);
      __ li(r4, Operand(FLAG_deopt_every_n_times));
      __ stw(r4, MemOperand(scratch));
      __ Pop(r4, scratch);
  
      __ Call(entry, RelocInfo::RUNTIME_ENTRY);
      __ bind(&no_deopt);
      __ stw(r4, MemOperand(scratch));
      __ Pop(r4, scratch);
    }
  
    if (info()->ShouldTrapOnDeopt()) {
      __ stop("trap_on_deopt", cond, kDefaultStopCode, cr);
    }
  
    Deoptimizer::DeoptInfo deopt_info = MakeDeoptInfo(instr, deopt_reason);
  
    DCHECK(info()->IsStub() || frame_is_built_);
    // Go through jump table if we need to handle condition, build frame, or
    // restore caller doubles.
    if (cond == al && frame_is_built_ && !info()->saves_caller_doubles()) {
      DeoptComment(deopt_info);
      __ Call(entry, RelocInfo::RUNTIME_ENTRY);
      info()->LogDeoptCallPosition(masm()->pc_offset(), deopt_info.inlining_id);
    } else {
      Deoptimizer::JumpTableEntry table_entry(entry, deopt_info, bailout_type,
                                              !frame_is_built_);
      // We often have several deopts to the same entry, reuse the last
      // jump entry if this is the case.
      if (FLAG_trace_deopt || isolate()->cpu_profiler()->is_profiling() ||
          jump_table_.is_empty() ||
          !table_entry.IsEquivalentTo(jump_table_.last())) {
        jump_table_.Add(table_entry, zone());
      }
      __ b(cond, &jump_table_.last().label, cr);
    }
  }
  
  
  void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
                              Deoptimizer::DeoptReason deopt_reason,
                              CRegister cr) {
    Deoptimizer::BailoutType bailout_type =
        info()->IsStub() ? Deoptimizer::LAZY : Deoptimizer::EAGER;
    DeoptimizeIf(condition, instr, deopt_reason, bailout_type, cr);
  }
  
  
  void LCodeGen::RecordSafepointWithLazyDeopt(LInstruction* instr,
                                              SafepointMode safepoint_mode) {
    if (safepoint_mode == RECORD_SIMPLE_SAFEPOINT) {
      RecordSafepoint(instr->pointer_map(), Safepoint::kLazyDeopt);
    } else {
      DCHECK(safepoint_mode == RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
      RecordSafepointWithRegisters(instr->pointer_map(), 0,
                                   Safepoint::kLazyDeopt);
    }
  }
  
  
  void LCodeGen::RecordSafepoint(LPointerMap* pointers, Safepoint::Kind kind,
                                 int arguments, Safepoint::DeoptMode deopt_mode) {
    DCHECK(expected_safepoint_kind_ == kind);
  
    const ZoneList<LOperand*>* operands = pointers->GetNormalizedOperands();
    Safepoint safepoint =
        safepoints_.DefineSafepoint(masm(), kind, arguments, deopt_mode);
    for (int i = 0; i < operands->length(); i++) {
      LOperand* pointer = operands->at(i);
      if (pointer->IsStackSlot()) {
        safepoint.DefinePointerSlot(pointer->index(), zone());
      } else if (pointer->IsRegister() && (kind & Safepoint::kWithRegisters)) {
        safepoint.DefinePointerRegister(ToRegister(pointer), zone());
      }
    }
  }
  
  
  void LCodeGen::RecordSafepoint(LPointerMap* pointers,
                                 Safepoint::DeoptMode deopt_mode) {
    RecordSafepoint(pointers, Safepoint::kSimple, 0, deopt_mode);
  }
  
  
  void LCodeGen::RecordSafepoint(Safepoint::DeoptMode deopt_mode) {
    LPointerMap empty_pointers(zone());
    RecordSafepoint(&empty_pointers, deopt_mode);
  }
  
  
  void LCodeGen::RecordSafepointWithRegisters(LPointerMap* pointers,
                                              int arguments,
                                              Safepoint::DeoptMode deopt_mode) {
    RecordSafepoint(pointers, Safepoint::kWithRegisters, arguments, deopt_mode);
  }
  
  
  void LCodeGen::RecordAndWritePosition(int position) {
    if (position == RelocInfo::kNoPosition) return;
    masm()->positions_recorder()->RecordPosition(position);
    masm()->positions_recorder()->WriteRecordedPositions();
  }
  
  
  static const char* LabelType(LLabel* label) {
    if (label->is_loop_header()) return " (loop header)";
    if (label->is_osr_entry()) return " (OSR entry)";
    return "";
  }
  
  
  void LCodeGen::DoLabel(LLabel* label) {
    Comment(";;; <@%d,#%d> -------------------- B%d%s --------------------",
            current_instruction_, label->hydrogen_value()->id(),
            label->block_id(), LabelType(label));
    __ bind(label->label());
    current_block_ = label->block_id();
    DoGap(label);
  }
  
  
  void LCodeGen::DoParallelMove(LParallelMove* move) { resolver_.Resolve(move); }
  
  
  void LCodeGen::DoGap(LGap* gap) {
    for (int i = LGap::FIRST_INNER_POSITION; i <= LGap::LAST_INNER_POSITION;
         i++) {
      LGap::InnerPosition inner_pos = static_cast<LGap::InnerPosition>(i);
      LParallelMove* move = gap->GetParallelMove(inner_pos);
      if (move != NULL) DoParallelMove(move);
    }
  }
  
  
  void LCodeGen::DoInstructionGap(LInstructionGap* instr) { DoGap(instr); }
  
  
  void LCodeGen::DoParameter(LParameter* instr) {
    // Nothing to do.
  }
  
  
  void LCodeGen::DoCallStub(LCallStub* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->result()).is(r3));
    switch (instr->hydrogen()->major_key()) {
      case CodeStub::RegExpExec: {
        RegExpExecStub stub(isolate());
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::SubString: {
        SubStringStub stub(isolate());
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      default:
        UNREACHABLE();
    }
  }
  
  
  void LCodeGen::DoUnknownOSRValue(LUnknownOSRValue* instr) {
    GenerateOsrPrologue();
  }
  
  
  void LCodeGen::DoModByPowerOf2I(LModByPowerOf2I* instr) {
    Register dividend = ToRegister(instr->dividend());
    int32_t divisor = instr->divisor();
    DCHECK(dividend.is(ToRegister(instr->result())));
  
    // Theoretically, a variation of the branch-free code for integer division by
    // a power of 2 (calculating the remainder via an additional multiplication
    // (which gets simplified to an 'and') and subtraction) should be faster, and
    // this is exactly what GCC and clang emit. Nevertheless, benchmarks seem to
    // indicate that positive dividends are heavily favored, so the branching
    // version performs better.
    HMod* hmod = instr->hydrogen();
    int32_t shift = WhichPowerOf2Abs(divisor);
    Label dividend_is_not_negative, done;
    if (hmod->CheckFlag(HValue::kLeftCanBeNegative)) {
      __ cmpwi(dividend, Operand::Zero());
      __ bge(&dividend_is_not_negative);
      if (shift) {
        // Note that this is correct even for kMinInt operands.
        __ neg(dividend, dividend);
        __ ExtractBitRange(dividend, dividend, shift - 1, 0);
        __ neg(dividend, dividend, LeaveOE, SetRC);
        if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
          DeoptimizeIf(eq, instr, Deoptimizer::kMinusZero, cr0);
        }
      } else if (!hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
        __ li(dividend, Operand::Zero());
      } else {
        DeoptimizeIf(al, instr, Deoptimizer::kMinusZero);
      }
      __ b(&done);
    }
  
    __ bind(&dividend_is_not_negative);
    if (shift) {
      __ ExtractBitRange(dividend, dividend, shift - 1, 0);
    } else {
      __ li(dividend, Operand::Zero());
    }
    __ bind(&done);
  }
  
  
  void LCodeGen::DoModByConstI(LModByConstI* instr) {
    Register dividend = ToRegister(instr->dividend());
    int32_t divisor = instr->divisor();
    Register result = ToRegister(instr->result());
    DCHECK(!dividend.is(result));
  
    if (divisor == 0) {
      DeoptimizeIf(al, instr, Deoptimizer::kDivisionByZero);
      return;
    }
  
    __ TruncatingDiv(result, dividend, Abs(divisor));
    __ mov(ip, Operand(Abs(divisor)));
    __ mullw(result, result, ip);
    __ sub(result, dividend, result, LeaveOE, SetRC);
  
    // Check for negative zero.
    HMod* hmod = instr->hydrogen();
    if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
      Label remainder_not_zero;
      __ bne(&remainder_not_zero, cr0);
      __ cmpwi(dividend, Operand::Zero());
      DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
      __ bind(&remainder_not_zero);
    }
  }
  
  
  void LCodeGen::DoModI(LModI* instr) {
    HMod* hmod = instr->hydrogen();
    Register left_reg = ToRegister(instr->left());
    Register right_reg = ToRegister(instr->right());
    Register result_reg = ToRegister(instr->result());
    Register scratch = scratch0();
    bool can_overflow = hmod->CheckFlag(HValue::kCanOverflow);
    Label done;
  
    if (can_overflow) {
      __ li(r0, Operand::Zero());  // clear xer
      __ mtxer(r0);
    }
  
    __ divw(scratch, left_reg, right_reg, SetOE, SetRC);
  
    // Check for x % 0.
    if (hmod->CheckFlag(HValue::kCanBeDivByZero)) {
      __ cmpwi(right_reg, Operand::Zero());
      DeoptimizeIf(eq, instr, Deoptimizer::kDivisionByZero);
    }
  
    // Check for kMinInt % -1, divw will return undefined, which is not what we
    // want. We have to deopt if we care about -0, because we can't return that.
    if (can_overflow) {
      if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
        DeoptimizeIf(overflow, instr, Deoptimizer::kMinusZero, cr0);
      } else {
        if (CpuFeatures::IsSupported(ISELECT)) {
          __ isel(overflow, result_reg, r0, result_reg, cr0);
          __ boverflow(&done, cr0);
        } else {
          Label no_overflow_possible;
          __ bnooverflow(&no_overflow_possible, cr0);
          __ li(result_reg, Operand::Zero());
          __ b(&done);
          __ bind(&no_overflow_possible);
        }
      }
    }
  
    __ mullw(scratch, right_reg, scratch);
    __ sub(result_reg, left_reg, scratch, LeaveOE, SetRC);
  
    // If we care about -0, test if the dividend is <0 and the result is 0.
    if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ bne(&done, cr0);
      __ cmpwi(left_reg, Operand::Zero());
      DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
    }
  
    __ bind(&done);
  }
  
  
  void LCodeGen::DoDivByPowerOf2I(LDivByPowerOf2I* instr) {
    Register dividend = ToRegister(instr->dividend());
    int32_t divisor = instr->divisor();
    Register result = ToRegister(instr->result());
    DCHECK(divisor == kMinInt || base::bits::IsPowerOfTwo32(Abs(divisor)));
    DCHECK(!result.is(dividend));
  
    // Check for (0 / -x) that will produce negative zero.
    HDiv* hdiv = instr->hydrogen();
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
      __ cmpwi(dividend, Operand::Zero());
      DeoptimizeIf(eq, instr, Deoptimizer::kMinusZero);
    }
    // Check for (kMinInt / -1).
    if (hdiv->CheckFlag(HValue::kCanOverflow) && divisor == -1) {
      __ lis(r0, Operand(SIGN_EXT_IMM16(0x8000)));
      __ cmpw(dividend, r0);
      DeoptimizeIf(eq, instr, Deoptimizer::kOverflow);
    }
  
    int32_t shift = WhichPowerOf2Abs(divisor);
  
    // Deoptimize if remainder will not be 0.
    if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32) && shift) {
      __ TestBitRange(dividend, shift - 1, 0, r0);
      DeoptimizeIf(ne, instr, Deoptimizer::kLostPrecision, cr0);
    }
  
    if (divisor == -1) {  // Nice shortcut, not needed for correctness.
      __ neg(result, dividend);
      return;
    }
    if (shift == 0) {
      __ mr(result, dividend);
    } else {
      if (shift == 1) {
        __ srwi(result, dividend, Operand(31));
      } else {
        __ srawi(result, dividend, 31);
        __ srwi(result, result, Operand(32 - shift));
      }
      __ add(result, dividend, result);
      __ srawi(result, result, shift);
    }
    if (divisor < 0) __ neg(result, result);
  }
  
  
  void LCodeGen::DoDivByConstI(LDivByConstI* instr) {
    Register dividend = ToRegister(instr->dividend());
    int32_t divisor = instr->divisor();
    Register result = ToRegister(instr->result());
    DCHECK(!dividend.is(result));
  
    if (divisor == 0) {
      DeoptimizeIf(al, instr, Deoptimizer::kDivisionByZero);
      return;
    }
  
    // Check for (0 / -x) that will produce negative zero.
    HDiv* hdiv = instr->hydrogen();
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
      __ cmpwi(dividend, Operand::Zero());
      DeoptimizeIf(eq, instr, Deoptimizer::kMinusZero);
    }
  
    __ TruncatingDiv(result, dividend, Abs(divisor));
    if (divisor < 0) __ neg(result, result);
  
    if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
      Register scratch = scratch0();
      __ mov(ip, Operand(divisor));
      __ mullw(scratch, result, ip);
      __ cmpw(scratch, dividend);
      DeoptimizeIf(ne, instr, Deoptimizer::kLostPrecision);
    }
  }
  
  
  // TODO(svenpanne) Refactor this to avoid code duplication with DoFlooringDivI.
  void LCodeGen::DoDivI(LDivI* instr) {
    HBinaryOperation* hdiv = instr->hydrogen();
    const Register dividend = ToRegister(instr->dividend());
    const Register divisor = ToRegister(instr->divisor());
    Register result = ToRegister(instr->result());
    bool can_overflow = hdiv->CheckFlag(HValue::kCanOverflow);
  
    DCHECK(!dividend.is(result));
    DCHECK(!divisor.is(result));
  
    if (can_overflow) {
      __ li(r0, Operand::Zero());  // clear xer
      __ mtxer(r0);
    }
  
    __ divw(result, dividend, divisor, SetOE, SetRC);
  
    // Check for x / 0.
    if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
      __ cmpwi(divisor, Operand::Zero());
      DeoptimizeIf(eq, instr, Deoptimizer::kDivisionByZero);
    }
  
    // Check for (0 / -x) that will produce negative zero.
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
      Label dividend_not_zero;
      __ cmpwi(dividend, Operand::Zero());
      __ bne(&dividend_not_zero);
      __ cmpwi(divisor, Operand::Zero());
      DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
      __ bind(&dividend_not_zero);
    }
  
    // Check for (kMinInt / -1).
    if (can_overflow) {
      if (!hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
        DeoptimizeIf(overflow, instr, Deoptimizer::kOverflow, cr0);
      } else {
        // When truncating, we want kMinInt / -1 = kMinInt.
        if (CpuFeatures::IsSupported(ISELECT)) {
          __ isel(overflow, result, dividend, result, cr0);
        } else {
          Label no_overflow_possible;
          __ bnooverflow(&no_overflow_possible, cr0);
          __ mr(result, dividend);
          __ bind(&no_overflow_possible);
        }
      }
    }
  
    if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
      // Deoptimize if remainder is not 0.
      Register scratch = scratch0();
      __ mullw(scratch, divisor, result);
      __ cmpw(dividend, scratch);
      DeoptimizeIf(ne, instr, Deoptimizer::kLostPrecision);
    }
  }
  
  
  void LCodeGen::DoFlooringDivByPowerOf2I(LFlooringDivByPowerOf2I* instr) {
    HBinaryOperation* hdiv = instr->hydrogen();
    Register dividend = ToRegister(instr->dividend());
    Register result = ToRegister(instr->result());
    int32_t divisor = instr->divisor();
    bool can_overflow = hdiv->CheckFlag(HValue::kLeftCanBeMinInt);
  
    // If the divisor is positive, things are easy: There can be no deopts and we
    // can simply do an arithmetic right shift.
    int32_t shift = WhichPowerOf2Abs(divisor);
    if (divisor > 0) {
      if (shift || !result.is(dividend)) {
        __ srawi(result, dividend, shift);
      }
      return;
    }
  
    // If the divisor is negative, we have to negate and handle edge cases.
    OEBit oe = LeaveOE;
  #if V8_TARGET_ARCH_PPC64
    if (divisor == -1 && can_overflow) {
      __ lis(r0, Operand(SIGN_EXT_IMM16(0x8000)));
      __ cmpw(dividend, r0);
      DeoptimizeIf(eq, instr, Deoptimizer::kOverflow);
    }
  #else
    if (can_overflow) {
      __ li(r0, Operand::Zero());  // clear xer
      __ mtxer(r0);
      oe = SetOE;
    }
  #endif
  
    __ neg(result, dividend, oe, SetRC);
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIf(eq, instr, Deoptimizer::kMinusZero, cr0);
    }
  
  // If the negation could not overflow, simply shifting is OK.
  #if !V8_TARGET_ARCH_PPC64
    if (!can_overflow) {
  #endif
      if (shift) {
        __ ShiftRightArithImm(result, result, shift);
      }
      return;
  #if !V8_TARGET_ARCH_PPC64
    }
  
    // Dividing by -1 is basically negation, unless we overflow.
    if (divisor == -1) {
      DeoptimizeIf(overflow, instr, Deoptimizer::kOverflow, cr0);
      return;
    }
  
    Label overflow, done;
    __ boverflow(&overflow, cr0);
    __ srawi(result, result, shift);
    __ b(&done);
    __ bind(&overflow);
    __ mov(result, Operand(kMinInt / divisor));
    __ bind(&done);
  #endif
  }
  
  
  void LCodeGen::DoFlooringDivByConstI(LFlooringDivByConstI* instr) {
    Register dividend = ToRegister(instr->dividend());
    int32_t divisor = instr->divisor();
    Register result = ToRegister(instr->result());
    DCHECK(!dividend.is(result));
  
    if (divisor == 0) {
      DeoptimizeIf(al, instr, Deoptimizer::kDivisionByZero);
      return;
    }
  
    // Check for (0 / -x) that will produce negative zero.
    HMathFloorOfDiv* hdiv = instr->hydrogen();
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
      __ cmpwi(dividend, Operand::Zero());
      DeoptimizeIf(eq, instr, Deoptimizer::kMinusZero);
    }
  
    // Easy case: We need no dynamic check for the dividend and the flooring
    // division is the same as the truncating division.
    if ((divisor > 0 && !hdiv->CheckFlag(HValue::kLeftCanBeNegative)) ||
        (divisor < 0 && !hdiv->CheckFlag(HValue::kLeftCanBePositive))) {
      __ TruncatingDiv(result, dividend, Abs(divisor));
      if (divisor < 0) __ neg(result, result);
      return;
    }
  
    // In the general case we may need to adjust before and after the truncating
    // division to get a flooring division.
    Register temp = ToRegister(instr->temp());
    DCHECK(!temp.is(dividend) && !temp.is(result));
    Label needs_adjustment, done;
    __ cmpwi(dividend, Operand::Zero());
    __ b(divisor > 0 ? lt : gt, &needs_adjustment);
    __ TruncatingDiv(result, dividend, Abs(divisor));
    if (divisor < 0) __ neg(result, result);
    __ b(&done);
    __ bind(&needs_adjustment);
    __ addi(temp, dividend, Operand(divisor > 0 ? 1 : -1));
    __ TruncatingDiv(result, temp, Abs(divisor));
    if (divisor < 0) __ neg(result, result);
    __ subi(result, result, Operand(1));
    __ bind(&done);
  }
  
  
  // TODO(svenpanne) Refactor this to avoid code duplication with DoDivI.
  void LCodeGen::DoFlooringDivI(LFlooringDivI* instr) {
    HBinaryOperation* hdiv = instr->hydrogen();
    const Register dividend = ToRegister(instr->dividend());
    const Register divisor = ToRegister(instr->divisor());
    Register result = ToRegister(instr->result());
    bool can_overflow = hdiv->CheckFlag(HValue::kCanOverflow);
  
    DCHECK(!dividend.is(result));
    DCHECK(!divisor.is(result));
  
    if (can_overflow) {
      __ li(r0, Operand::Zero());  // clear xer
      __ mtxer(r0);
    }
  
    __ divw(result, dividend, divisor, SetOE, SetRC);
  
    // Check for x / 0.
    if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
      __ cmpwi(divisor, Operand::Zero());
      DeoptimizeIf(eq, instr, Deoptimizer::kDivisionByZero);
    }
  
    // Check for (0 / -x) that will produce negative zero.
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
      Label dividend_not_zero;
      __ cmpwi(dividend, Operand::Zero());
      __ bne(&dividend_not_zero);
      __ cmpwi(divisor, Operand::Zero());
      DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
      __ bind(&dividend_not_zero);
    }
  
    // Check for (kMinInt / -1).
    if (can_overflow) {
      if (!hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
        DeoptimizeIf(overflow, instr, Deoptimizer::kOverflow, cr0);
      } else {
        // When truncating, we want kMinInt / -1 = kMinInt.
        if (CpuFeatures::IsSupported(ISELECT)) {
          __ isel(overflow, result, dividend, result, cr0);
        } else {
          Label no_overflow_possible;
          __ bnooverflow(&no_overflow_possible, cr0);
          __ mr(result, dividend);
          __ bind(&no_overflow_possible);
        }
      }
    }
  
    Label done;
    Register scratch = scratch0();
  // If both operands have the same sign then we are done.
  #if V8_TARGET_ARCH_PPC64
    __ xor_(scratch, dividend, divisor);
    __ cmpwi(scratch, Operand::Zero());
    __ bge(&done);
  #else
    __ xor_(scratch, dividend, divisor, SetRC);
    __ bge(&done, cr0);
  #endif
  
    // If there is no remainder then we are done.
    __ mullw(scratch, divisor, result);
    __ cmpw(dividend, scratch);
    __ beq(&done);
  
    // We performed a truncating division. Correct the result.
    __ subi(result, result, Operand(1));
    __ bind(&done);
  }
  
  
  void LCodeGen::DoMultiplyAddD(LMultiplyAddD* instr) {
    DoubleRegister addend = ToDoubleRegister(instr->addend());
    DoubleRegister multiplier = ToDoubleRegister(instr->multiplier());
    DoubleRegister multiplicand = ToDoubleRegister(instr->multiplicand());
    DoubleRegister result = ToDoubleRegister(instr->result());
  
    __ fmadd(result, multiplier, multiplicand, addend);
  }
  
  
  void LCodeGen::DoMultiplySubD(LMultiplySubD* instr) {
    DoubleRegister minuend = ToDoubleRegister(instr->minuend());
    DoubleRegister multiplier = ToDoubleRegister(instr->multiplier());
    DoubleRegister multiplicand = ToDoubleRegister(instr->multiplicand());
    DoubleRegister result = ToDoubleRegister(instr->result());
  
    __ fmsub(result, multiplier, multiplicand, minuend);
  }
  
  
  void LCodeGen::DoMulI(LMulI* instr) {
    Register scratch = scratch0();
    Register result = ToRegister(instr->result());
    // Note that result may alias left.
    Register left = ToRegister(instr->left());
    LOperand* right_op = instr->right();
  
    bool bailout_on_minus_zero =
        instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
  
    if (right_op->IsConstantOperand()) {
      int32_t constant = ToInteger32(LConstantOperand::cast(right_op));
  
      if (bailout_on_minus_zero && (constant < 0)) {
        // The case of a null constant will be handled separately.
        // If constant is negative and left is null, the result should be -0.
        __ cmpi(left, Operand::Zero());
        DeoptimizeIf(eq, instr, Deoptimizer::kMinusZero);
      }
  
      switch (constant) {
        case -1:
          if (can_overflow) {
  #if V8_TARGET_ARCH_PPC64
            if (instr->hydrogen()->representation().IsSmi()) {
  #endif
              __ li(r0, Operand::Zero());  // clear xer
              __ mtxer(r0);
              __ neg(result, left, SetOE, SetRC);
              DeoptimizeIf(overflow, instr, Deoptimizer::kOverflow, cr0);
  #if V8_TARGET_ARCH_PPC64
            } else {
              __ neg(result, left);
              __ TestIfInt32(result, r0);
              DeoptimizeIf(ne, instr, Deoptimizer::kOverflow);
            }
  #endif
          } else {
            __ neg(result, left);
          }
          break;
        case 0:
          if (bailout_on_minus_zero) {
  // If left is strictly negative and the constant is null, the
  // result is -0. Deoptimize if required, otherwise return 0.
  #if V8_TARGET_ARCH_PPC64
            if (instr->hydrogen()->representation().IsSmi()) {
  #endif
              __ cmpi(left, Operand::Zero());
  #if V8_TARGET_ARCH_PPC64
            } else {
              __ cmpwi(left, Operand::Zero());
            }
  #endif
            DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
          }
          __ li(result, Operand::Zero());
          break;
        case 1:
          __ Move(result, left);
          break;
        default:
          // Multiplying by powers of two and powers of two plus or minus
          // one can be done faster with shifted operands.
          // For other constants we emit standard code.
          int32_t mask = constant >> 31;
          uint32_t constant_abs = (constant + mask) ^ mask;
  
          if (base::bits::IsPowerOfTwo32(constant_abs)) {
            int32_t shift = WhichPowerOf2(constant_abs);
            __ ShiftLeftImm(result, left, Operand(shift));
            // Correct the sign of the result if the constant is negative.
            if (constant < 0) __ neg(result, result);
          } else if (base::bits::IsPowerOfTwo32(constant_abs - 1)) {
            int32_t shift = WhichPowerOf2(constant_abs - 1);
            __ ShiftLeftImm(scratch, left, Operand(shift));
            __ add(result, scratch, left);
            // Correct the sign of the result if the constant is negative.
            if (constant < 0) __ neg(result, result);
          } else if (base::bits::IsPowerOfTwo32(constant_abs + 1)) {
            int32_t shift = WhichPowerOf2(constant_abs + 1);
            __ ShiftLeftImm(scratch, left, Operand(shift));
            __ sub(result, scratch, left);
            // Correct the sign of the result if the constant is negative.
            if (constant < 0) __ neg(result, result);
          } else {
            // Generate standard code.
            __ mov(ip, Operand(constant));
            __ Mul(result, left, ip);
          }
      }
  
    } else {
      DCHECK(right_op->IsRegister());
      Register right = ToRegister(right_op);
  
      if (can_overflow) {
  #if V8_TARGET_ARCH_PPC64
        // result = left * right.
        if (instr->hydrogen()->representation().IsSmi()) {
          __ SmiUntag(result, left);
          __ SmiUntag(scratch, right);
          __ Mul(result, result, scratch);
        } else {
          __ Mul(result, left, right);
        }
        __ TestIfInt32(result, r0);
        DeoptimizeIf(ne, instr, Deoptimizer::kOverflow);
        if (instr->hydrogen()->representation().IsSmi()) {
          __ SmiTag(result);
        }
  #else
        // scratch:result = left * right.
        if (instr->hydrogen()->representation().IsSmi()) {
          __ SmiUntag(result, left);
          __ mulhw(scratch, result, right);
          __ mullw(result, result, right);
        } else {
          __ mulhw(scratch, left, right);
          __ mullw(result, left, right);
        }
        __ TestIfInt32(scratch, result, r0);
        DeoptimizeIf(ne, instr, Deoptimizer::kOverflow);
  #endif
      } else {
        if (instr->hydrogen()->representation().IsSmi()) {
          __ SmiUntag(result, left);
          __ Mul(result, result, right);
        } else {
          __ Mul(result, left, right);
        }
      }
  
      if (bailout_on_minus_zero) {
        Label done;
  #if V8_TARGET_ARCH_PPC64
        if (instr->hydrogen()->representation().IsSmi()) {
  #endif
          __ xor_(r0, left, right, SetRC);
          __ bge(&done, cr0);
  #if V8_TARGET_ARCH_PPC64
        } else {
          __ xor_(r0, left, right);
          __ cmpwi(r0, Operand::Zero());
          __ bge(&done);
        }
  #endif
        // Bail out if the result is minus zero.
        __ cmpi(result, Operand::Zero());
        DeoptimizeIf(eq, instr, Deoptimizer::kMinusZero);
        __ bind(&done);
      }
    }
  }
  
  
  void LCodeGen::DoBitI(LBitI* instr) {
    LOperand* left_op = instr->left();
    LOperand* right_op = instr->right();
    DCHECK(left_op->IsRegister());
    Register left = ToRegister(left_op);
    Register result = ToRegister(instr->result());
    Operand right(no_reg);
  
    if (right_op->IsStackSlot()) {
      right = Operand(EmitLoadRegister(right_op, ip));
    } else {
      DCHECK(right_op->IsRegister() || right_op->IsConstantOperand());
      right = ToOperand(right_op);
  
      if (right_op->IsConstantOperand() && is_uint16(right.immediate())) {
        switch (instr->op()) {
          case Token::BIT_AND:
            __ andi(result, left, right);
            break;
          case Token::BIT_OR:
            __ ori(result, left, right);
            break;
          case Token::BIT_XOR:
            __ xori(result, left, right);
            break;
          default:
            UNREACHABLE();
            break;
        }
        return;
      }
    }
  
    switch (instr->op()) {
      case Token::BIT_AND:
        __ And(result, left, right);
        break;
      case Token::BIT_OR:
        __ Or(result, left, right);
        break;
      case Token::BIT_XOR:
        if (right_op->IsConstantOperand() && right.immediate() == int32_t(~0)) {
          __ notx(result, left);
        } else {
          __ Xor(result, left, right);
        }
        break;
      default:
        UNREACHABLE();
        break;
    }
  }
  
  
  void LCodeGen::DoShiftI(LShiftI* instr) {
    // Both 'left' and 'right' are "used at start" (see LCodeGen::DoShift), so
    // result may alias either of them.
    LOperand* right_op = instr->right();
    Register left = ToRegister(instr->left());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
    if (right_op->IsRegister()) {
      // Mask the right_op operand.
      __ andi(scratch, ToRegister(right_op), Operand(0x1F));
      switch (instr->op()) {
        case Token::ROR:
          // rotate_right(a, b) == rotate_left(a, 32 - b)
          __ subfic(scratch, scratch, Operand(32));
          __ rotlw(result, left, scratch);
          break;
        case Token::SAR:
          __ sraw(result, left, scratch);
          break;
        case Token::SHR:
          if (instr->can_deopt()) {
            __ srw(result, left, scratch, SetRC);
  #if V8_TARGET_ARCH_PPC64
            __ extsw(result, result, SetRC);
  #endif
            DeoptimizeIf(lt, instr, Deoptimizer::kNegativeValue, cr0);
          } else {
            __ srw(result, left, scratch);
          }
          break;
        case Token::SHL:
          __ slw(result, left, scratch);
  #if V8_TARGET_ARCH_PPC64
          __ extsw(result, result);
  #endif
          break;
        default:
          UNREACHABLE();
          break;
      }
    } else {
      // Mask the right_op operand.
      int value = ToInteger32(LConstantOperand::cast(right_op));
      uint8_t shift_count = static_cast<uint8_t>(value & 0x1F);
      switch (instr->op()) {
        case Token::ROR:
          if (shift_count != 0) {
            __ rotrwi(result, left, shift_count);
          } else {
            __ Move(result, left);
          }
          break;
        case Token::SAR:
          if (shift_count != 0) {
            __ srawi(result, left, shift_count);
          } else {
            __ Move(result, left);
          }
          break;
        case Token::SHR:
          if (shift_count != 0) {
            __ srwi(result, left, Operand(shift_count));
          } else {
            if (instr->can_deopt()) {
              __ cmpwi(left, Operand::Zero());
              DeoptimizeIf(lt, instr, Deoptimizer::kNegativeValue);
            }
            __ Move(result, left);
          }
          break;
        case Token::SHL:
          if (shift_count != 0) {
  #if V8_TARGET_ARCH_PPC64
            if (instr->hydrogen_value()->representation().IsSmi()) {
              __ sldi(result, left, Operand(shift_count));
  #else
            if (instr->hydrogen_value()->representation().IsSmi() &&
                instr->can_deopt()) {
              if (shift_count != 1) {
                __ slwi(result, left, Operand(shift_count - 1));
                __ SmiTagCheckOverflow(result, result, scratch);
              } else {
                __ SmiTagCheckOverflow(result, left, scratch);
              }
              DeoptimizeIf(lt, instr, Deoptimizer::kOverflow, cr0);
  #endif
            } else {
              __ slwi(result, left, Operand(shift_count));
  #if V8_TARGET_ARCH_PPC64
              __ extsw(result, result);
  #endif
            }
          } else {
            __ Move(result, left);
          }
          break;
        default:
          UNREACHABLE();
          break;
      }
    }
  }
  
  
  void LCodeGen::DoSubI(LSubI* instr) {
    LOperand* right = instr->right();
    Register left = ToRegister(instr->left());
    Register result = ToRegister(instr->result());
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
  #if V8_TARGET_ARCH_PPC64
    const bool isInteger = !instr->hydrogen()->representation().IsSmi();
  #else
    const bool isInteger = false;
  #endif
    if (!can_overflow || isInteger) {
      if (right->IsConstantOperand()) {
        __ Add(result, left, -(ToOperand(right).immediate()), r0);
      } else {
        __ sub(result, left, EmitLoadRegister(right, ip));
      }
  #if V8_TARGET_ARCH_PPC64
      if (can_overflow) {
        __ TestIfInt32(result, r0);
        DeoptimizeIf(ne, instr, Deoptimizer::kOverflow);
      }
  #endif
    } else {
      if (right->IsConstantOperand()) {
        __ AddAndCheckForOverflow(result, left, -(ToOperand(right).immediate()),
                                  scratch0(), r0);
      } else {
        __ SubAndCheckForOverflow(result, left, EmitLoadRegister(right, ip),
                                  scratch0(), r0);
      }
      DeoptimizeIf(lt, instr, Deoptimizer::kOverflow, cr0);
    }
  }
  
  
  void LCodeGen::DoRSubI(LRSubI* instr) {
    LOperand* left = instr->left();
    LOperand* right = instr->right();
    LOperand* result = instr->result();
  
    DCHECK(!instr->hydrogen()->CheckFlag(HValue::kCanOverflow) &&
           right->IsConstantOperand());
  
    Operand right_operand = ToOperand(right);
    if (is_int16(right_operand.immediate())) {
      __ subfic(ToRegister(result), ToRegister(left), right_operand);
    } else {
      __ mov(r0, right_operand);
      __ sub(ToRegister(result), r0, ToRegister(left));
    }
  }
  
  
  void LCodeGen::DoConstantI(LConstantI* instr) {
    __ mov(ToRegister(instr->result()), Operand(instr->value()));
  }
  
  
  void LCodeGen::DoConstantS(LConstantS* instr) {
    __ LoadSmiLiteral(ToRegister(instr->result()), instr->value());
  }
  
  
  void LCodeGen::DoConstantD(LConstantD* instr) {
    DCHECK(instr->result()->IsDoubleRegister());
    DoubleRegister result = ToDoubleRegister(instr->result());
  #if V8_HOST_ARCH_IA32
    // Need some crappy work-around for x87 sNaN -> qNaN breakage in simulator
    // builds.
    uint64_t bits = instr->bits();
    if ((bits & V8_UINT64_C(0x7FF8000000000000)) ==
        V8_UINT64_C(0x7FF0000000000000)) {
      uint32_t lo = static_cast<uint32_t>(bits);
      uint32_t hi = static_cast<uint32_t>(bits >> 32);
      __ mov(ip, Operand(lo));
      __ mov(scratch0(), Operand(hi));
      __ MovInt64ToDouble(result, scratch0(), ip);
      return;
    }
  #endif
    double v = instr->value();
    __ LoadDoubleLiteral(result, v, scratch0());
  }
  
  
  void LCodeGen::DoConstantE(LConstantE* instr) {
    __ mov(ToRegister(instr->result()), Operand(instr->value()));
  }
  
  
  void LCodeGen::DoConstantT(LConstantT* instr) {
    Handle<Object> object = instr->value(isolate());
    AllowDeferredHandleDereference smi_check;
    __ Move(ToRegister(instr->result()), object);
  }
  
  
  void LCodeGen::DoMapEnumLength(LMapEnumLength* instr) {
    Register result = ToRegister(instr->result());
    Register map = ToRegister(instr->value());
    __ EnumLength(result, map);
  }
  
  
  MemOperand LCodeGen::BuildSeqStringOperand(Register string, LOperand* index,
                                             String::Encoding encoding) {
    if (index->IsConstantOperand()) {
      int offset = ToInteger32(LConstantOperand::cast(index));
      if (encoding == String::TWO_BYTE_ENCODING) {
        offset *= kUC16Size;
      }
      STATIC_ASSERT(kCharSize == 1);
      return FieldMemOperand(string, SeqString::kHeaderSize + offset);
    }
    Register scratch = scratch0();
    DCHECK(!scratch.is(string));
    DCHECK(!scratch.is(ToRegister(index)));
    if (encoding == String::ONE_BYTE_ENCODING) {
      __ add(scratch, string, ToRegister(index));
    } else {
      STATIC_ASSERT(kUC16Size == 2);
      __ ShiftLeftImm(scratch, ToRegister(index), Operand(1));
      __ add(scratch, string, scratch);
    }
    return FieldMemOperand(scratch, SeqString::kHeaderSize);
  }
  
  
  void LCodeGen::DoSeqStringGetChar(LSeqStringGetChar* instr) {
    String::Encoding encoding = instr->hydrogen()->encoding();
    Register string = ToRegister(instr->string());
    Register result = ToRegister(instr->result());
  
    if (FLAG_debug_code) {
      Register scratch = scratch0();
      __ LoadP(scratch, FieldMemOperand(string, HeapObject::kMapOffset));
      __ lbz(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
  
      __ andi(scratch, scratch,
              Operand(kStringRepresentationMask | kStringEncodingMask));
      static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
      static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
      __ cmpi(scratch,
              Operand(encoding == String::ONE_BYTE_ENCODING ? one_byte_seq_type
                                                            : two_byte_seq_type));
      __ Check(eq, kUnexpectedStringType);
    }
  
    MemOperand operand = BuildSeqStringOperand(string, instr->index(), encoding);
    if (encoding == String::ONE_BYTE_ENCODING) {
      __ lbz(result, operand);
    } else {
      __ lhz(result, operand);
    }
  }
  
  
  void LCodeGen::DoSeqStringSetChar(LSeqStringSetChar* instr) {
    String::Encoding encoding = instr->hydrogen()->encoding();
    Register string = ToRegister(instr->string());
    Register value = ToRegister(instr->value());
  
    if (FLAG_debug_code) {
      Register index = ToRegister(instr->index());
      static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
      static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
      int encoding_mask =
          instr->hydrogen()->encoding() == String::ONE_BYTE_ENCODING
              ? one_byte_seq_type
              : two_byte_seq_type;
      __ EmitSeqStringSetCharCheck(string, index, value, encoding_mask);
    }
  
    MemOperand operand = BuildSeqStringOperand(string, instr->index(), encoding);
    if (encoding == String::ONE_BYTE_ENCODING) {
      __ stb(value, operand);
    } else {
      __ sth(value, operand);
    }
  }
  
  
  void LCodeGen::DoAddI(LAddI* instr) {
    LOperand* right = instr->right();
    Register left = ToRegister(instr->left());
    Register result = ToRegister(instr->result());
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
  #if V8_TARGET_ARCH_PPC64
    const bool isInteger = !(instr->hydrogen()->representation().IsSmi() ||
                             instr->hydrogen()->representation().IsExternal());
  #else
    const bool isInteger = false;
  #endif
  
    if (!can_overflow || isInteger) {
      if (right->IsConstantOperand()) {
        __ Add(result, left, ToOperand(right).immediate(), r0);
      } else {
        __ add(result, left, EmitLoadRegister(right, ip));
      }
  #if V8_TARGET_ARCH_PPC64
      if (can_overflow) {
        __ TestIfInt32(result, r0);
        DeoptimizeIf(ne, instr, Deoptimizer::kOverflow);
      }
  #endif
    } else {
      if (right->IsConstantOperand()) {
        __ AddAndCheckForOverflow(result, left, ToOperand(right).immediate(),
                                  scratch0(), r0);
      } else {
        __ AddAndCheckForOverflow(result, left, EmitLoadRegister(right, ip),
                                  scratch0(), r0);
      }
      DeoptimizeIf(lt, instr, Deoptimizer::kOverflow, cr0);
    }
  }
  
  
  void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
    LOperand* left = instr->left();
    LOperand* right = instr->right();
    HMathMinMax::Operation operation = instr->hydrogen()->operation();
    Condition cond = (operation == HMathMinMax::kMathMin) ? le : ge;
    if (instr->hydrogen()->representation().IsSmiOrInteger32()) {
      Register left_reg = ToRegister(left);
      Register right_reg = EmitLoadRegister(right, ip);
      Register result_reg = ToRegister(instr->result());
      Label return_left, done;
  #if V8_TARGET_ARCH_PPC64
      if (instr->hydrogen_value()->representation().IsSmi()) {
  #endif
        __ cmp(left_reg, right_reg);
  #if V8_TARGET_ARCH_PPC64
      } else {
        __ cmpw(left_reg, right_reg);
      }
  #endif
      if (CpuFeatures::IsSupported(ISELECT)) {
        __ isel(cond, result_reg, left_reg, right_reg);
      } else {
        __ b(cond, &return_left);
        __ Move(result_reg, right_reg);
        __ b(&done);
        __ bind(&return_left);
        __ Move(result_reg, left_reg);
        __ bind(&done);
      }
    } else {
      DCHECK(instr->hydrogen()->representation().IsDouble());
      DoubleRegister left_reg = ToDoubleRegister(left);
      DoubleRegister right_reg = ToDoubleRegister(right);
      DoubleRegister result_reg = ToDoubleRegister(instr->result());
      Label check_nan_left, check_zero, return_left, return_right, done;
      __ fcmpu(left_reg, right_reg);
      __ bunordered(&check_nan_left);
      __ beq(&check_zero);
      __ b(cond, &return_left);
      __ b(&return_right);
  
      __ bind(&check_zero);
      __ fcmpu(left_reg, kDoubleRegZero);
      __ bne(&return_left);  // left == right != 0.
  
      // At this point, both left and right are either 0 or -0.
      // N.B. The following works because +0 + -0 == +0
      if (operation == HMathMinMax::kMathMin) {
        // For min we want logical-or of sign bit: -(-L + -R)
        __ fneg(left_reg, left_reg);
        __ fsub(result_reg, left_reg, right_reg);
        __ fneg(result_reg, result_reg);
      } else {
        // For max we want logical-and of sign bit: (L + R)
        __ fadd(result_reg, left_reg, right_reg);
      }
      __ b(&done);
  
      __ bind(&check_nan_left);
      __ fcmpu(left_reg, left_reg);
      __ bunordered(&return_left);  // left == NaN.
  
      __ bind(&return_right);
      if (!right_reg.is(result_reg)) {
        __ fmr(result_reg, right_reg);
      }
      __ b(&done);
  
      __ bind(&return_left);
      if (!left_reg.is(result_reg)) {
        __ fmr(result_reg, left_reg);
      }
      __ bind(&done);
    }
  }
  
  
  void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
    DoubleRegister left = ToDoubleRegister(instr->left());
    DoubleRegister right = ToDoubleRegister(instr->right());
    DoubleRegister result = ToDoubleRegister(instr->result());
    switch (instr->op()) {
      case Token::ADD:
        __ fadd(result, left, right);
        break;
      case Token::SUB:
        __ fsub(result, left, right);
        break;
      case Token::MUL:
        __ fmul(result, left, right);
        break;
      case Token::DIV:
        __ fdiv(result, left, right);
        break;
      case Token::MOD: {
        __ PrepareCallCFunction(0, 2, scratch0());
        __ MovToFloatParameters(left, right);
        __ CallCFunction(ExternalReference::mod_two_doubles_operation(isolate()),
                         0, 2);
        // Move the result in the double result register.
        __ MovFromFloatResult(result);
        break;
      }
      default:
        UNREACHABLE();
        break;
    }
  }
  
  
  void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->left()).is(r4));
    DCHECK(ToRegister(instr->right()).is(r3));
    DCHECK(ToRegister(instr->result()).is(r3));
  
    Handle<Code> code =
        CodeFactory::BinaryOpIC(isolate(), instr->op(), instr->strength()).code();
    CallCode(code, RelocInfo::CODE_TARGET, instr);
  }
  
  
  template <class InstrType>
  void LCodeGen::EmitBranch(InstrType instr, Condition cond, CRegister cr) {
    int left_block = instr->TrueDestination(chunk_);
    int right_block = instr->FalseDestination(chunk_);
  
    int next_block = GetNextEmittedBlock();
  
    if (right_block == left_block || cond == al) {
      EmitGoto(left_block);
    } else if (left_block == next_block) {
      __ b(NegateCondition(cond), chunk_->GetAssemblyLabel(right_block), cr);
    } else if (right_block == next_block) {
      __ b(cond, chunk_->GetAssemblyLabel(left_block), cr);
    } else {
      __ b(cond, chunk_->GetAssemblyLabel(left_block), cr);
      __ b(chunk_->GetAssemblyLabel(right_block));
    }
  }
  
  
  template <class InstrType>
  void LCodeGen::EmitTrueBranch(InstrType instr, Condition cond, CRegister cr) {
    int true_block = instr->TrueDestination(chunk_);
    __ b(cond, chunk_->GetAssemblyLabel(true_block), cr);
  }
  
  
  template <class InstrType>
  void LCodeGen::EmitFalseBranch(InstrType instr, Condition cond, CRegister cr) {
    int false_block = instr->FalseDestination(chunk_);
    __ b(cond, chunk_->GetAssemblyLabel(false_block), cr);
  }
  
  
  void LCodeGen::DoDebugBreak(LDebugBreak* instr) { __ stop("LBreak"); }
  
  
  void LCodeGen::DoBranch(LBranch* instr) {
    Representation r = instr->hydrogen()->value()->representation();
    DoubleRegister dbl_scratch = double_scratch0();
    const uint crZOrNaNBits = (1 << (31 - Assembler::encode_crbit(cr7, CR_EQ)) |
                               1 << (31 - Assembler::encode_crbit(cr7, CR_FU)));
  
    if (r.IsInteger32()) {
      DCHECK(!info()->IsStub());
      Register reg = ToRegister(instr->value());
      __ cmpwi(reg, Operand::Zero());
      EmitBranch(instr, ne);
    } else if (r.IsSmi()) {
      DCHECK(!info()->IsStub());
      Register reg = ToRegister(instr->value());
      __ cmpi(reg, Operand::Zero());
      EmitBranch(instr, ne);
    } else if (r.IsDouble()) {
      DCHECK(!info()->IsStub());
      DoubleRegister reg = ToDoubleRegister(instr->value());
      // Test the double value. Zero and NaN are false.
      __ fcmpu(reg, kDoubleRegZero, cr7);
      __ mfcr(r0);
      __ andi(r0, r0, Operand(crZOrNaNBits));
      EmitBranch(instr, eq, cr0);
    } else {
      DCHECK(r.IsTagged());
      Register reg = ToRegister(instr->value());
      HType type = instr->hydrogen()->value()->type();
      if (type.IsBoolean()) {
        DCHECK(!info()->IsStub());
        __ CompareRoot(reg, Heap::kTrueValueRootIndex);
        EmitBranch(instr, eq);
      } else if (type.IsSmi()) {
        DCHECK(!info()->IsStub());
        __ cmpi(reg, Operand::Zero());
        EmitBranch(instr, ne);
      } else if (type.IsJSArray()) {
        DCHECK(!info()->IsStub());
        EmitBranch(instr, al);
      } else if (type.IsHeapNumber()) {
        DCHECK(!info()->IsStub());
        __ lfd(dbl_scratch, FieldMemOperand(reg, HeapNumber::kValueOffset));
        // Test the double value. Zero and NaN are false.
        __ fcmpu(dbl_scratch, kDoubleRegZero, cr7);
        __ mfcr(r0);
        __ andi(r0, r0, Operand(crZOrNaNBits));
        EmitBranch(instr, eq, cr0);
      } else if (type.IsString()) {
        DCHECK(!info()->IsStub());
        __ LoadP(ip, FieldMemOperand(reg, String::kLengthOffset));
        __ cmpi(ip, Operand::Zero());
        EmitBranch(instr, ne);
      } else {
        ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
        // Avoid deopts in the case where we've never executed this path before.
        if (expected.IsEmpty()) expected = ToBooleanStub::Types::Generic();
  
        if (expected.Contains(ToBooleanStub::UNDEFINED)) {
          // undefined -> false.
          __ CompareRoot(reg, Heap::kUndefinedValueRootIndex);
          __ beq(instr->FalseLabel(chunk_));
        }
        if (expected.Contains(ToBooleanStub::BOOLEAN)) {
          // Boolean -> its value.
          __ CompareRoot(reg, Heap::kTrueValueRootIndex);
          __ beq(instr->TrueLabel(chunk_));
          __ CompareRoot(reg, Heap::kFalseValueRootIndex);
          __ beq(instr->FalseLabel(chunk_));
        }
        if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
          // 'null' -> false.
          __ CompareRoot(reg, Heap::kNullValueRootIndex);
          __ beq(instr->FalseLabel(chunk_));
        }
  
        if (expected.Contains(ToBooleanStub::SMI)) {
          // Smis: 0 -> false, all other -> true.
          __ cmpi(reg, Operand::Zero());
          __ beq(instr->FalseLabel(chunk_));
          __ JumpIfSmi(reg, instr->TrueLabel(chunk_));
        } else if (expected.NeedsMap()) {
          // If we need a map later and have a Smi -> deopt.
          __ TestIfSmi(reg, r0);
          DeoptimizeIf(eq, instr, Deoptimizer::kSmi, cr0);
        }
  
        const Register map = scratch0();
        if (expected.NeedsMap()) {
          __ LoadP(map, FieldMemOperand(reg, HeapObject::kMapOffset));
  
          if (expected.CanBeUndetectable()) {
            // Undetectable -> false.
            __ lbz(ip, FieldMemOperand(map, Map::kBitFieldOffset));
            __ TestBit(ip, Map::kIsUndetectable, r0);
            __ bne(instr->FalseLabel(chunk_), cr0);
          }
        }
  
        if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
          // spec object -> true.
          __ CompareInstanceType(map, ip, FIRST_JS_RECEIVER_TYPE);
          __ bge(instr->TrueLabel(chunk_));
        }
  
        if (expected.Contains(ToBooleanStub::STRING)) {
          // String value -> false iff empty.
          Label not_string;
          __ CompareInstanceType(map, ip, FIRST_NONSTRING_TYPE);
          __ bge(&not_string);
          __ LoadP(ip, FieldMemOperand(reg, String::kLengthOffset));
          __ cmpi(ip, Operand::Zero());
          __ bne(instr->TrueLabel(chunk_));
          __ b(instr->FalseLabel(chunk_));
          __ bind(&not_string);
        }
  
        if (expected.Contains(ToBooleanStub::SYMBOL)) {
          // Symbol value -> true.
          __ CompareInstanceType(map, ip, SYMBOL_TYPE);
          __ beq(instr->TrueLabel(chunk_));
        }
  
        if (expected.Contains(ToBooleanStub::SIMD_VALUE)) {
          // SIMD value -> true.
          Label not_simd;
          __ CompareInstanceType(map, ip, SIMD128_VALUE_TYPE);
          __ beq(instr->TrueLabel(chunk_));
        }
  
        if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
          // heap number -> false iff +0, -0, or NaN.
          Label not_heap_number;
          __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
          __ bne(&not_heap_number);
          __ lfd(dbl_scratch, FieldMemOperand(reg, HeapNumber::kValueOffset));
          // Test the double value. Zero and NaN are false.
          __ fcmpu(dbl_scratch, kDoubleRegZero, cr7);
          __ mfcr(r0);
          __ andi(r0, r0, Operand(crZOrNaNBits));
          __ bne(instr->FalseLabel(chunk_), cr0);
          __ b(instr->TrueLabel(chunk_));
          __ bind(&not_heap_number);
        }
  
        if (!expected.IsGeneric()) {
          // We've seen something for the first time -> deopt.
          // This can only happen if we are not generic already.
          DeoptimizeIf(al, instr, Deoptimizer::kUnexpectedObject);
        }
      }
    }
  }
  
  
  void LCodeGen::EmitGoto(int block) {
    if (!IsNextEmittedBlock(block)) {
      __ b(chunk_->GetAssemblyLabel(LookupDestination(block)));
    }
  }
  
  
  void LCodeGen::DoGoto(LGoto* instr) { EmitGoto(instr->block_id()); }
  
  
  Condition LCodeGen::TokenToCondition(Token::Value op) {
    Condition cond = kNoCondition;
    switch (op) {
      case Token::EQ:
      case Token::EQ_STRICT:
        cond = eq;
        break;
      case Token::NE:
      case Token::NE_STRICT:
        cond = ne;
        break;
      case Token::LT:
        cond = lt;
        break;
      case Token::GT:
        cond = gt;
        break;
      case Token::LTE:
        cond = le;
        break;
      case Token::GTE:
        cond = ge;
        break;
      case Token::IN:
      case Token::INSTANCEOF:
      default:
        UNREACHABLE();
    }
    return cond;
  }
  
  
  void LCodeGen::DoCompareNumericAndBranch(LCompareNumericAndBranch* instr) {
    LOperand* left = instr->left();
    LOperand* right = instr->right();
    bool is_unsigned =
        instr->hydrogen()->left()->CheckFlag(HInstruction::kUint32) ||
        instr->hydrogen()->right()->CheckFlag(HInstruction::kUint32);
    Condition cond = TokenToCondition(instr->op());
  
    if (left->IsConstantOperand() && right->IsConstantOperand()) {
      // We can statically evaluate the comparison.
      double left_val = ToDouble(LConstantOperand::cast(left));
      double right_val = ToDouble(LConstantOperand::cast(right));
      int next_block = EvalComparison(instr->op(), left_val, right_val)
                           ? instr->TrueDestination(chunk_)
                           : instr->FalseDestination(chunk_);
      EmitGoto(next_block);
    } else {
      if (instr->is_double()) {
        // Compare left and right operands as doubles and load the
        // resulting flags into the normal status register.
        __ fcmpu(ToDoubleRegister(left), ToDoubleRegister(right));
        // If a NaN is involved, i.e. the result is unordered,
        // jump to false block label.
        __ bunordered(instr->FalseLabel(chunk_));
      } else {
        if (right->IsConstantOperand()) {
          int32_t value = ToInteger32(LConstantOperand::cast(right));
          if (instr->hydrogen_value()->representation().IsSmi()) {
            if (is_unsigned) {
              __ CmplSmiLiteral(ToRegister(left), Smi::FromInt(value), r0);
            } else {
              __ CmpSmiLiteral(ToRegister(left), Smi::FromInt(value), r0);
            }
          } else {
            if (is_unsigned) {
              __ Cmplwi(ToRegister(left), Operand(value), r0);
            } else {
              __ Cmpwi(ToRegister(left), Operand(value), r0);
            }
          }
        } else if (left->IsConstantOperand()) {
          int32_t value = ToInteger32(LConstantOperand::cast(left));
          if (instr->hydrogen_value()->representation().IsSmi()) {
            if (is_unsigned) {
              __ CmplSmiLiteral(ToRegister(right), Smi::FromInt(value), r0);
            } else {
              __ CmpSmiLiteral(ToRegister(right), Smi::FromInt(value), r0);
            }
          } else {
            if (is_unsigned) {
              __ Cmplwi(ToRegister(right), Operand(value), r0);
            } else {
              __ Cmpwi(ToRegister(right), Operand(value), r0);
            }
          }
          // We commuted the operands, so commute the condition.
          cond = CommuteCondition(cond);
        } else if (instr->hydrogen_value()->representation().IsSmi()) {
          if (is_unsigned) {
            __ cmpl(ToRegister(left), ToRegister(right));
          } else {
            __ cmp(ToRegister(left), ToRegister(right));
          }
        } else {
          if (is_unsigned) {
            __ cmplw(ToRegister(left), ToRegister(right));
          } else {
            __ cmpw(ToRegister(left), ToRegister(right));
          }
        }
      }
      EmitBranch(instr, cond);
    }
  }
  
  
  void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
    Register left = ToRegister(instr->left());
    Register right = ToRegister(instr->right());
  
    __ cmp(left, right);
    EmitBranch(instr, eq);
  }
  
  
  void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
    if (instr->hydrogen()->representation().IsTagged()) {
      Register input_reg = ToRegister(instr->object());
      __ mov(ip, Operand(factory()->the_hole_value()));
      __ cmp(input_reg, ip);
      EmitBranch(instr, eq);
      return;
    }
  
    DoubleRegister input_reg = ToDoubleRegister(instr->object());
    __ fcmpu(input_reg, input_reg);
    EmitFalseBranch(instr, ordered);
  
    Register scratch = scratch0();
    __ MovDoubleHighToInt(scratch, input_reg);
    __ Cmpi(scratch, Operand(kHoleNanUpper32), r0);
    EmitBranch(instr, eq);
  }
  
  
  void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
    Representation rep = instr->hydrogen()->value()->representation();
    DCHECK(!rep.IsInteger32());
    Register scratch = ToRegister(instr->temp());
  
    if (rep.IsDouble()) {
      DoubleRegister value = ToDoubleRegister(instr->value());
      __ fcmpu(value, kDoubleRegZero);
      EmitFalseBranch(instr, ne);
  #if V8_TARGET_ARCH_PPC64
      __ MovDoubleToInt64(scratch, value);
  #else
      __ MovDoubleHighToInt(scratch, value);
  #endif
      __ cmpi(scratch, Operand::Zero());
      EmitBranch(instr, lt);
    } else {
      Register value = ToRegister(instr->value());
      __ CheckMap(value, scratch, Heap::kHeapNumberMapRootIndex,
                  instr->FalseLabel(chunk()), DO_SMI_CHECK);
  #if V8_TARGET_ARCH_PPC64
      __ LoadP(scratch, FieldMemOperand(value, HeapNumber::kValueOffset));
      __ li(ip, Operand(1));
      __ rotrdi(ip, ip, 1);  // ip = 0x80000000_00000000
      __ cmp(scratch, ip);
  #else
      __ lwz(scratch, FieldMemOperand(value, HeapNumber::kExponentOffset));
      __ lwz(ip, FieldMemOperand(value, HeapNumber::kMantissaOffset));
      Label skip;
      __ lis(r0, Operand(SIGN_EXT_IMM16(0x8000)));
      __ cmp(scratch, r0);
      __ bne(&skip);
      __ cmpi(ip, Operand::Zero());
      __ bind(&skip);
  #endif
      EmitBranch(instr, eq);
    }
  }
  
  
  Condition LCodeGen::EmitIsString(Register input, Register temp1,
                                   Label* is_not_string,
                                   SmiCheck check_needed = INLINE_SMI_CHECK) {
    if (check_needed == INLINE_SMI_CHECK) {
      __ JumpIfSmi(input, is_not_string);
    }
    __ CompareObjectType(input, temp1, temp1, FIRST_NONSTRING_TYPE);
  
    return lt;
  }
  
  
  void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
    Register reg = ToRegister(instr->value());
    Register temp1 = ToRegister(instr->temp());
  
    SmiCheck check_needed = instr->hydrogen()->value()->type().IsHeapObject()
                                ? OMIT_SMI_CHECK
                                : INLINE_SMI_CHECK;
    Condition true_cond =
        EmitIsString(reg, temp1, instr->FalseLabel(chunk_), check_needed);
  
    EmitBranch(instr, true_cond);
  }
  
  
  void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
    Register input_reg = EmitLoadRegister(instr->value(), ip);
    __ TestIfSmi(input_reg, r0);
    EmitBranch(instr, eq, cr0);
  }
  
  
  void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
    Register input = ToRegister(instr->value());
    Register temp = ToRegister(instr->temp());
  
    if (!instr->hydrogen()->value()->type().IsHeapObject()) {
      __ JumpIfSmi(input, instr->FalseLabel(chunk_));
    }
    __ LoadP(temp, FieldMemOperand(input, HeapObject::kMapOffset));
    __ lbz(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
    __ TestBit(temp, Map::kIsUndetectable, r0);
    EmitBranch(instr, ne, cr0);
  }
  
  
  static Condition ComputeCompareCondition(Token::Value op) {
    switch (op) {
      case Token::EQ_STRICT:
      case Token::EQ:
        return eq;
      case Token::LT:
        return lt;
      case Token::GT:
        return gt;
      case Token::LTE:
        return le;
      case Token::GTE:
        return ge;
      default:
        UNREACHABLE();
        return kNoCondition;
    }
  }
  
  
  void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->left()).is(r4));
    DCHECK(ToRegister(instr->right()).is(r3));
  
    Handle<Code> code = CodeFactory::StringCompare(isolate()).code();
    CallCode(code, RelocInfo::CODE_TARGET, instr);
    __ cmpi(r3, Operand::Zero());
  
    EmitBranch(instr, ComputeCompareCondition(instr->op()));
  }
  
  
  static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
    InstanceType from = instr->from();
    InstanceType to = instr->to();
    if (from == FIRST_TYPE) return to;
    DCHECK(from == to || to == LAST_TYPE);
    return from;
  }
  
  
  static Condition BranchCondition(HHasInstanceTypeAndBranch* instr) {
    InstanceType from = instr->from();
    InstanceType to = instr->to();
    if (from == to) return eq;
    if (to == LAST_TYPE) return ge;
    if (from == FIRST_TYPE) return le;
    UNREACHABLE();
    return eq;
  }
  
  
  void LCodeGen::DoHasInstanceTypeAndBranch(LHasInstanceTypeAndBranch* instr) {
    Register scratch = scratch0();
    Register input = ToRegister(instr->value());
  
    if (!instr->hydrogen()->value()->type().IsHeapObject()) {
      __ JumpIfSmi(input, instr->FalseLabel(chunk_));
    }
  
    __ CompareObjectType(input, scratch, scratch, TestType(instr->hydrogen()));
    EmitBranch(instr, BranchCondition(instr->hydrogen()));
  }
  
  
  void LCodeGen::DoGetCachedArrayIndex(LGetCachedArrayIndex* instr) {
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
  
    __ AssertString(input);
  
    __ lwz(result, FieldMemOperand(input, String::kHashFieldOffset));
    __ IndexFromHash(result, result);
  }
  
  
  void LCodeGen::DoHasCachedArrayIndexAndBranch(
      LHasCachedArrayIndexAndBranch* instr) {
    Register input = ToRegister(instr->value());
    Register scratch = scratch0();
  
    __ lwz(scratch, FieldMemOperand(input, String::kHashFieldOffset));
    __ mov(r0, Operand(String::kContainsCachedArrayIndexMask));
    __ and_(r0, scratch, r0, SetRC);
    EmitBranch(instr, eq, cr0);
  }
  
  
  // Branches to a label or falls through with the answer in flags.  Trashes
  // the temp registers, but not the input.
  void LCodeGen::EmitClassOfTest(Label* is_true, Label* is_false,
                                 Handle<String> class_name, Register input,
                                 Register temp, Register temp2) {
    DCHECK(!input.is(temp));
    DCHECK(!input.is(temp2));
    DCHECK(!temp.is(temp2));
  
    __ JumpIfSmi(input, is_false);
  
    __ CompareObjectType(input, temp, temp2, JS_FUNCTION_TYPE);
    if (String::Equals(isolate()->factory()->Function_string(), class_name)) {
      __ beq(is_true);
    } else {
      __ beq(is_false);
    }
  
    // Check if the constructor in the map is a function.
    Register instance_type = ip;
    __ GetMapConstructor(temp, temp, temp2, instance_type);
  
    // Objects with a non-function constructor have class 'Object'.
    __ cmpi(instance_type, Operand(JS_FUNCTION_TYPE));
    if (String::Equals(isolate()->factory()->Object_string(), class_name)) {
      __ bne(is_true);
    } else {
      __ bne(is_false);
    }
  
    // temp now contains the constructor function. Grab the
    // instance class name from there.
    __ LoadP(temp, FieldMemOperand(temp, JSFunction::kSharedFunctionInfoOffset));
    __ LoadP(temp,
             FieldMemOperand(temp, SharedFunctionInfo::kInstanceClassNameOffset));
    // The class name we are testing against is internalized since it's a literal.
    // The name in the constructor is internalized because of the way the context
    // is booted.  This routine isn't expected to work for random API-created
    // classes and it doesn't have to because you can't access it with natives
    // syntax.  Since both sides are internalized it is sufficient to use an
    // identity comparison.
    __ Cmpi(temp, Operand(class_name), r0);
    // End with the answer in flags.
  }
  
  
  void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
    Register input = ToRegister(instr->value());
    Register temp = scratch0();
    Register temp2 = ToRegister(instr->temp());
    Handle<String> class_name = instr->hydrogen()->class_name();
  
    EmitClassOfTest(instr->TrueLabel(chunk_), instr->FalseLabel(chunk_),
                    class_name, input, temp, temp2);
  
    EmitBranch(instr, eq);
  }
  
  
  void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
    Register reg = ToRegister(instr->value());
    Register temp = ToRegister(instr->temp());
  
    __ LoadP(temp, FieldMemOperand(reg, HeapObject::kMapOffset));
    __ Cmpi(temp, Operand(instr->map()), r0);
    EmitBranch(instr, eq);
  }
  
  
  void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->left()).is(InstanceOfDescriptor::LeftRegister()));
    DCHECK(ToRegister(instr->right()).is(InstanceOfDescriptor::RightRegister()));
    DCHECK(ToRegister(instr->result()).is(r3));
    InstanceOfStub stub(isolate());
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoHasInPrototypeChainAndBranch(
      LHasInPrototypeChainAndBranch* instr) {
    Register const object = ToRegister(instr->object());
    Register const object_map = scratch0();
    Register const object_instance_type = ip;
    Register const object_prototype = object_map;
    Register const prototype = ToRegister(instr->prototype());
  
    // The {object} must be a spec object.  It's sufficient to know that {object}
    // is not a smi, since all other non-spec objects have {null} prototypes and
    // will be ruled out below.
    if (instr->hydrogen()->ObjectNeedsSmiCheck()) {
      __ TestIfSmi(object, r0);
      EmitFalseBranch(instr, eq, cr0);
    }
  
    // Loop through the {object}s prototype chain looking for the {prototype}.
    __ LoadP(object_map, FieldMemOperand(object, HeapObject::kMapOffset));
    Label loop;
    __ bind(&loop);
  
    // Deoptimize if the object needs to be access checked.
    __ lbz(object_instance_type,
           FieldMemOperand(object_map, Map::kBitFieldOffset));
    __ TestBit(object_instance_type, Map::kIsAccessCheckNeeded, r0);
    DeoptimizeIf(ne, instr, Deoptimizer::kAccessCheck, cr0);
    // Deoptimize for proxies.
    __ CompareInstanceType(object_map, object_instance_type, JS_PROXY_TYPE);
    DeoptimizeIf(eq, instr, Deoptimizer::kProxy);
    __ LoadP(object_prototype,
             FieldMemOperand(object_map, Map::kPrototypeOffset));
    __ cmp(object_prototype, prototype);
    EmitTrueBranch(instr, eq);
    __ CompareRoot(object_prototype, Heap::kNullValueRootIndex);
    EmitFalseBranch(instr, eq);
    __ LoadP(object_map,
             FieldMemOperand(object_prototype, HeapObject::kMapOffset));
    __ b(&loop);
  }
  
  
  void LCodeGen::DoCmpT(LCmpT* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    Token::Value op = instr->op();
  
    Handle<Code> ic =
        CodeFactory::CompareIC(isolate(), op, instr->strength()).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
    // This instruction also signals no smi code inlined
    __ cmpi(r3, Operand::Zero());
  
    Condition condition = ComputeCompareCondition(op);
    if (CpuFeatures::IsSupported(ISELECT)) {
      __ LoadRoot(r4, Heap::kTrueValueRootIndex);
      __ LoadRoot(r5, Heap::kFalseValueRootIndex);
      __ isel(condition, ToRegister(instr->result()), r4, r5);
    } else {
      Label true_value, done;
  
      __ b(condition, &true_value);
  
      __ LoadRoot(ToRegister(instr->result()), Heap::kFalseValueRootIndex);
      __ b(&done);
  
      __ bind(&true_value);
      __ LoadRoot(ToRegister(instr->result()), Heap::kTrueValueRootIndex);
  
      __ bind(&done);
    }
  }
  
  
  void LCodeGen::DoReturn(LReturn* instr) {
    if (FLAG_trace && info()->IsOptimizing()) {
      // Push the return value on the stack as the parameter.
      // Runtime::TraceExit returns its parameter in r3.  We're leaving the code
      // managed by the register allocator and tearing down the frame, it's
      // safe to write to the context register.
      __ push(r3);
      __ LoadP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
      __ CallRuntime(Runtime::kTraceExit);
    }
    if (info()->saves_caller_doubles()) {
      RestoreCallerDoubles();
    }
    if (instr->has_constant_parameter_count()) {
      int parameter_count = ToInteger32(instr->constant_parameter_count());
      int32_t sp_delta = (parameter_count + 1) * kPointerSize;
      if (NeedsEagerFrame()) {
        masm_->LeaveFrame(StackFrame::JAVA_SCRIPT, sp_delta);
      } else if (sp_delta != 0) {
        __ addi(sp, sp, Operand(sp_delta));
      }
    } else {
      DCHECK(info()->IsStub());  // Functions would need to drop one more value.
      Register reg = ToRegister(instr->parameter_count());
      // The argument count parameter is a smi
      if (NeedsEagerFrame()) {
        masm_->LeaveFrame(StackFrame::JAVA_SCRIPT);
      }
      __ SmiToPtrArrayOffset(r0, reg);
      __ add(sp, sp, r0);
    }
  
    __ blr();
  }
  
  
  template <class T>
  void LCodeGen::EmitVectorLoadICRegisters(T* instr) {
    Register vector_register = ToRegister(instr->temp_vector());
    Register slot_register = LoadDescriptor::SlotRegister();
    DCHECK(vector_register.is(LoadWithVectorDescriptor::VectorRegister()));
    DCHECK(slot_register.is(r3));
  
    AllowDeferredHandleDereference vector_structure_check;
    Handle<TypeFeedbackVector> vector = instr->hydrogen()->feedback_vector();
    __ Move(vector_register, vector);
    // No need to allocate this register.
    FeedbackVectorSlot slot = instr->hydrogen()->slot();
    int index = vector->GetIndex(slot);
    __ LoadSmiLiteral(slot_register, Smi::FromInt(index));
  }
  
  
  template <class T>
  void LCodeGen::EmitVectorStoreICRegisters(T* instr) {
    Register vector_register = ToRegister(instr->temp_vector());
    Register slot_register = ToRegister(instr->temp_slot());
  
    AllowDeferredHandleDereference vector_structure_check;
    Handle<TypeFeedbackVector> vector = instr->hydrogen()->feedback_vector();
    __ Move(vector_register, vector);
    FeedbackVectorSlot slot = instr->hydrogen()->slot();
    int index = vector->GetIndex(slot);
    __ LoadSmiLiteral(slot_register, Smi::FromInt(index));
  }
  
  
  void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->global_object())
               .is(LoadDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->result()).is(r3));
  
    __ mov(LoadDescriptor::NameRegister(), Operand(instr->name()));
    EmitVectorLoadICRegisters<LLoadGlobalGeneric>(instr);
    Handle<Code> ic =
        CodeFactory::LoadICInOptimizedCode(isolate(), instr->typeof_mode(),
                                           SLOPPY, PREMONOMORPHIC).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
    Register context = ToRegister(instr->context());
    Register result = ToRegister(instr->result());
    __ LoadP(result, ContextMemOperand(context, instr->slot_index()));
    if (instr->hydrogen()->RequiresHoleCheck()) {
      __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
      if (instr->hydrogen()->DeoptimizesOnHole()) {
        __ cmp(result, ip);
        DeoptimizeIf(eq, instr, Deoptimizer::kHole);
      } else {
        if (CpuFeatures::IsSupported(ISELECT)) {
          Register scratch = scratch0();
          __ mov(scratch, Operand(factory()->undefined_value()));
          __ cmp(result, ip);
          __ isel(eq, result, scratch, result);
        } else {
          Label skip;
          __ cmp(result, ip);
          __ bne(&skip);
          __ mov(result, Operand(factory()->undefined_value()));
          __ bind(&skip);
        }
      }
    }
  }
  
  
  void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
    Register context = ToRegister(instr->context());
    Register value = ToRegister(instr->value());
    Register scratch = scratch0();
    MemOperand target = ContextMemOperand(context, instr->slot_index());
  
    Label skip_assignment;
  
    if (instr->hydrogen()->RequiresHoleCheck()) {
      __ LoadP(scratch, target);
      __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
      __ cmp(scratch, ip);
      if (instr->hydrogen()->DeoptimizesOnHole()) {
        DeoptimizeIf(eq, instr, Deoptimizer::kHole);
      } else {
        __ bne(&skip_assignment);
      }
    }
  
    __ StoreP(value, target, r0);
    if (instr->hydrogen()->NeedsWriteBarrier()) {
      SmiCheck check_needed = instr->hydrogen()->value()->type().IsHeapObject()
                                  ? OMIT_SMI_CHECK
                                  : INLINE_SMI_CHECK;
      __ RecordWriteContextSlot(context, target.offset(), value, scratch,
                                GetLinkRegisterState(), kSaveFPRegs,
                                EMIT_REMEMBERED_SET, check_needed);
    }
  
    __ bind(&skip_assignment);
  }
  
  
  void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
    HObjectAccess access = instr->hydrogen()->access();
    int offset = access.offset();
    Register object = ToRegister(instr->object());
  
    if (access.IsExternalMemory()) {
      Register result = ToRegister(instr->result());
      MemOperand operand = MemOperand(object, offset);
      __ LoadRepresentation(result, operand, access.representation(), r0);
      return;
    }
  
    if (instr->hydrogen()->representation().IsDouble()) {
      DCHECK(access.IsInobject());
      DoubleRegister result = ToDoubleRegister(instr->result());
      __ lfd(result, FieldMemOperand(object, offset));
      return;
    }
  
    Register result = ToRegister(instr->result());
    if (!access.IsInobject()) {
      __ LoadP(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
      object = result;
    }
  
    Representation representation = access.representation();
  
  #if V8_TARGET_ARCH_PPC64
    // 64-bit Smi optimization
    if (representation.IsSmi() &&
        instr->hydrogen()->representation().IsInteger32()) {
      // Read int value directly from upper half of the smi.
      offset = SmiWordOffset(offset);
      representation = Representation::Integer32();
    }
  #endif
  
    __ LoadRepresentation(result, FieldMemOperand(object, offset), representation,
                          r0);
  }
  
  
  void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->result()).is(r3));
  
    // Name is always in r5.
    __ mov(LoadDescriptor::NameRegister(), Operand(instr->name()));
    EmitVectorLoadICRegisters<LLoadNamedGeneric>(instr);
    Handle<Code> ic =
        CodeFactory::LoadICInOptimizedCode(
            isolate(), NOT_INSIDE_TYPEOF, instr->hydrogen()->language_mode(),
            instr->hydrogen()->initialization_state()).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
    Register scratch = scratch0();
    Register function = ToRegister(instr->function());
    Register result = ToRegister(instr->result());
  
    // Get the prototype or initial map from the function.
    __ LoadP(result,
             FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
  
    // Check that the function has a prototype or an initial map.
    __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
    __ cmp(result, ip);
    DeoptimizeIf(eq, instr, Deoptimizer::kHole);
  
    // If the function does not have an initial map, we're done.
    if (CpuFeatures::IsSupported(ISELECT)) {
      // Get the prototype from the initial map (optimistic).
      __ LoadP(ip, FieldMemOperand(result, Map::kPrototypeOffset));
      __ CompareObjectType(result, scratch, scratch, MAP_TYPE);
      __ isel(eq, result, ip, result);
    } else {
      Label done;
      __ CompareObjectType(result, scratch, scratch, MAP_TYPE);
      __ bne(&done);
  
      // Get the prototype from the initial map.
      __ LoadP(result, FieldMemOperand(result, Map::kPrototypeOffset));
  
      // All done.
      __ bind(&done);
    }
  }
  
  
  void LCodeGen::DoLoadRoot(LLoadRoot* instr) {
    Register result = ToRegister(instr->result());
    __ LoadRoot(result, instr->index());
  }
  
  
  void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
    Register arguments = ToRegister(instr->arguments());
    Register result = ToRegister(instr->result());
    // There are two words between the frame pointer and the last argument.
    // Subtracting from length accounts for one of them add one more.
    if (instr->length()->IsConstantOperand()) {
      int const_length = ToInteger32(LConstantOperand::cast(instr->length()));
      if (instr->index()->IsConstantOperand()) {
        int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
        int index = (const_length - const_index) + 1;
        __ LoadP(result, MemOperand(arguments, index * kPointerSize), r0);
      } else {
        Register index = ToRegister(instr->index());
        __ subfic(result, index, Operand(const_length + 1));
        __ ShiftLeftImm(result, result, Operand(kPointerSizeLog2));
        __ LoadPX(result, MemOperand(arguments, result));
      }
    } else if (instr->index()->IsConstantOperand()) {
      Register length = ToRegister(instr->length());
      int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
      int loc = const_index - 1;
      if (loc != 0) {
        __ subi(result, length, Operand(loc));
        __ ShiftLeftImm(result, result, Operand(kPointerSizeLog2));
        __ LoadPX(result, MemOperand(arguments, result));
      } else {
        __ ShiftLeftImm(result, length, Operand(kPointerSizeLog2));
        __ LoadPX(result, MemOperand(arguments, result));
      }
    } else {
      Register length = ToRegister(instr->length());
      Register index = ToRegister(instr->index());
      __ sub(result, length, index);
      __ addi(result, result, Operand(1));
      __ ShiftLeftImm(result, result, Operand(kPointerSizeLog2));
      __ LoadPX(result, MemOperand(arguments, result));
    }
  }
  
  
  void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
    Register external_pointer = ToRegister(instr->elements());
    Register key = no_reg;
    ElementsKind elements_kind = instr->elements_kind();
    bool key_is_constant = instr->key()->IsConstantOperand();
    int constant_key = 0;
    if (key_is_constant) {
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xF0000000) {
        Abort(kArrayIndexConstantValueTooBig);
      }
    } else {
      key = ToRegister(instr->key());
    }
    int element_size_shift = ElementsKindToShiftSize(elements_kind);
    bool key_is_smi = instr->hydrogen()->key()->representation().IsSmi();
    int base_offset = instr->base_offset();
  
    if (elements_kind == FLOAT32_ELEMENTS || elements_kind == FLOAT64_ELEMENTS) {
      DoubleRegister result = ToDoubleRegister(instr->result());
      if (key_is_constant) {
        __ Add(scratch0(), external_pointer, constant_key << element_size_shift,
               r0);
      } else {
        __ IndexToArrayOffset(r0, key, element_size_shift, key_is_smi);
        __ add(scratch0(), external_pointer, r0);
      }
      if (elements_kind == FLOAT32_ELEMENTS) {
        __ lfs(result, MemOperand(scratch0(), base_offset));
      } else {  // i.e. elements_kind == EXTERNAL_DOUBLE_ELEMENTS
        __ lfd(result, MemOperand(scratch0(), base_offset));
      }
    } else {
      Register result = ToRegister(instr->result());
      MemOperand mem_operand =
          PrepareKeyedOperand(key, external_pointer, key_is_constant, key_is_smi,
                              constant_key, element_size_shift, base_offset);
      switch (elements_kind) {
        case INT8_ELEMENTS:
          if (key_is_constant) {
            __ LoadByte(result, mem_operand, r0);
          } else {
            __ lbzx(result, mem_operand);
          }
          __ extsb(result, result);
          break;
        case UINT8_ELEMENTS:
        case UINT8_CLAMPED_ELEMENTS:
          if (key_is_constant) {
            __ LoadByte(result, mem_operand, r0);
          } else {
            __ lbzx(result, mem_operand);
          }
          break;
        case INT16_ELEMENTS:
          if (key_is_constant) {
            __ LoadHalfWordArith(result, mem_operand, r0);
          } else {
            __ lhax(result, mem_operand);
          }
          break;
        case UINT16_ELEMENTS:
          if (key_is_constant) {
            __ LoadHalfWord(result, mem_operand, r0);
          } else {
            __ lhzx(result, mem_operand);
          }
          break;
        case INT32_ELEMENTS:
          if (key_is_constant) {
            __ LoadWordArith(result, mem_operand, r0);
          } else {
            __ lwax(result, mem_operand);
          }
          break;
        case UINT32_ELEMENTS:
          if (key_is_constant) {
            __ LoadWord(result, mem_operand, r0);
          } else {
            __ lwzx(result, mem_operand);
          }
          if (!instr->hydrogen()->CheckFlag(HInstruction::kUint32)) {
            __ lis(r0, Operand(SIGN_EXT_IMM16(0x8000)));
            __ cmplw(result, r0);
            DeoptimizeIf(ge, instr, Deoptimizer::kNegativeValue);
          }
          break;
        case FLOAT32_ELEMENTS:
        case FLOAT64_ELEMENTS:
        case FAST_HOLEY_DOUBLE_ELEMENTS:
        case FAST_HOLEY_ELEMENTS:
        case FAST_HOLEY_SMI_ELEMENTS:
        case FAST_DOUBLE_ELEMENTS:
        case FAST_ELEMENTS:
        case FAST_SMI_ELEMENTS:
        case DICTIONARY_ELEMENTS:
        case FAST_SLOPPY_ARGUMENTS_ELEMENTS:
        case SLOW_SLOPPY_ARGUMENTS_ELEMENTS:
          UNREACHABLE();
          break;
      }
    }
  }
  
  
  void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
    Register elements = ToRegister(instr->elements());
    bool key_is_constant = instr->key()->IsConstantOperand();
    Register key = no_reg;
    DoubleRegister result = ToDoubleRegister(instr->result());
    Register scratch = scratch0();
  
    int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
    bool key_is_smi = instr->hydrogen()->key()->representation().IsSmi();
    int constant_key = 0;
    if (key_is_constant) {
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xF0000000) {
        Abort(kArrayIndexConstantValueTooBig);
      }
    } else {
      key = ToRegister(instr->key());
    }
  
    int base_offset = instr->base_offset() + constant_key * kDoubleSize;
    if (!key_is_constant) {
      __ IndexToArrayOffset(r0, key, element_size_shift, key_is_smi);
      __ add(scratch, elements, r0);
      elements = scratch;
    }
    if (!is_int16(base_offset)) {
      __ Add(scratch, elements, base_offset, r0);
      base_offset = 0;
      elements = scratch;
    }
    __ lfd(result, MemOperand(elements, base_offset));
  
    if (instr->hydrogen()->RequiresHoleCheck()) {
      if (is_int16(base_offset + Register::kExponentOffset)) {
        __ lwz(scratch,
               MemOperand(elements, base_offset + Register::kExponentOffset));
      } else {
        __ addi(scratch, elements, Operand(base_offset));
        __ lwz(scratch, MemOperand(scratch, Register::kExponentOffset));
      }
      __ Cmpi(scratch, Operand(kHoleNanUpper32), r0);
      DeoptimizeIf(eq, instr, Deoptimizer::kHole);
    }
  }
  
  
  void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
    HLoadKeyed* hinstr = instr->hydrogen();
    Register elements = ToRegister(instr->elements());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
    Register store_base = scratch;
    int offset = instr->base_offset();
  
    if (instr->key()->IsConstantOperand()) {
      LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
      offset += ToInteger32(const_operand) * kPointerSize;
      store_base = elements;
    } else {
      Register key = ToRegister(instr->key());
      // Even though the HLoadKeyed instruction forces the input
      // representation for the key to be an integer, the input gets replaced
      // during bound check elimination with the index argument to the bounds
      // check, which can be tagged, so that case must be handled here, too.
      if (hinstr->key()->representation().IsSmi()) {
        __ SmiToPtrArrayOffset(r0, key);
      } else {
        __ ShiftLeftImm(r0, key, Operand(kPointerSizeLog2));
      }
      __ add(scratch, elements, r0);
    }
  
    bool requires_hole_check = hinstr->RequiresHoleCheck();
    Representation representation = hinstr->representation();
  
  #if V8_TARGET_ARCH_PPC64
    // 64-bit Smi optimization
    if (representation.IsInteger32() &&
        hinstr->elements_kind() == FAST_SMI_ELEMENTS) {
      DCHECK(!requires_hole_check);
      // Read int value directly from upper half of the smi.
      offset = SmiWordOffset(offset);
    }
  #endif
  
    __ LoadRepresentation(result, MemOperand(store_base, offset), representation,
                          r0);
  
    // Check for the hole value.
    if (requires_hole_check) {
      if (IsFastSmiElementsKind(hinstr->elements_kind())) {
        __ TestIfSmi(result, r0);
        DeoptimizeIf(ne, instr, Deoptimizer::kNotASmi, cr0);
      } else {
        __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
        __ cmp(result, scratch);
        DeoptimizeIf(eq, instr, Deoptimizer::kHole);
      }
    } else if (instr->hydrogen()->hole_mode() == CONVERT_HOLE_TO_UNDEFINED) {
      DCHECK(instr->hydrogen()->elements_kind() == FAST_HOLEY_ELEMENTS);
      Label done;
      __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
      __ cmp(result, scratch);
      __ bne(&done);
      if (info()->IsStub()) {
        // A stub can safely convert the hole to undefined only if the array
        // protector cell contains (Smi) Isolate::kArrayProtectorValid. Otherwise
        // it needs to bail out.
        __ LoadRoot(result, Heap::kArrayProtectorRootIndex);
        __ LoadP(result, FieldMemOperand(result, Cell::kValueOffset));
        __ CmpSmiLiteral(result, Smi::FromInt(Isolate::kArrayProtectorValid), r0);
        DeoptimizeIf(ne, instr, Deoptimizer::kHole);
      }
      __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
      __ bind(&done);
    }
  }
  
  
  void LCodeGen::DoLoadKeyed(LLoadKeyed* instr) {
    if (instr->is_fixed_typed_array()) {
      DoLoadKeyedExternalArray(instr);
    } else if (instr->hydrogen()->representation().IsDouble()) {
      DoLoadKeyedFixedDoubleArray(instr);
    } else {
      DoLoadKeyedFixedArray(instr);
    }
  }
  
  
  MemOperand LCodeGen::PrepareKeyedOperand(Register key, Register base,
                                           bool key_is_constant, bool key_is_smi,
                                           int constant_key,
                                           int element_size_shift,
                                           int base_offset) {
    Register scratch = scratch0();
  
    if (key_is_constant) {
      return MemOperand(base, (constant_key << element_size_shift) + base_offset);
    }
  
    bool needs_shift =
        (element_size_shift != (key_is_smi ? kSmiTagSize + kSmiShiftSize : 0));
  
    if (!(base_offset || needs_shift)) {
      return MemOperand(base, key);
    }
  
    if (needs_shift) {
      __ IndexToArrayOffset(scratch, key, element_size_shift, key_is_smi);
      key = scratch;
    }
  
    if (base_offset) {
      __ Add(scratch, key, base_offset, r0);
    }
  
    return MemOperand(base, scratch);
  }
  
  
  void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
  
    if (instr->hydrogen()->HasVectorAndSlot()) {
      EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
    }
  
    Handle<Code> ic = CodeFactory::KeyedLoadICInOptimizedCode(
                          isolate(), instr->hydrogen()->language_mode(),
                          instr->hydrogen()->initialization_state()).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
    Register scratch = scratch0();
    Register result = ToRegister(instr->result());
  
    if (instr->hydrogen()->from_inlined()) {
      __ subi(result, sp, Operand(2 * kPointerSize));
    } else {
      // Check if the calling frame is an arguments adaptor frame.
      __ LoadP(scratch, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
      __ LoadP(result,
               MemOperand(scratch, StandardFrameConstants::kContextOffset));
      __ CmpSmiLiteral(result, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR), r0);
  
      // Result is the frame pointer for the frame if not adapted and for the real
      // frame below the adaptor frame if adapted.
      if (CpuFeatures::IsSupported(ISELECT)) {
        __ isel(eq, result, scratch, fp);
      } else {
        Label done, adapted;
        __ beq(&adapted);
        __ mr(result, fp);
        __ b(&done);
  
        __ bind(&adapted);
        __ mr(result, scratch);
        __ bind(&done);
      }
    }
  }
  
  
  void LCodeGen::DoArgumentsLength(LArgumentsLength* instr) {
    Register elem = ToRegister(instr->elements());
    Register result = ToRegister(instr->result());
  
    Label done;
  
    // If no arguments adaptor frame the number of arguments is fixed.
    __ cmp(fp, elem);
    __ mov(result, Operand(scope()->num_parameters()));
    __ beq(&done);
  
    // Arguments adaptor frame present. Get argument length from there.
    __ LoadP(result, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ LoadP(result,
             MemOperand(result, ArgumentsAdaptorFrameConstants::kLengthOffset));
    __ SmiUntag(result);
  
    // Argument length is in result register.
    __ bind(&done);
  }
  
  
  void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
    Register receiver = ToRegister(instr->receiver());
    Register function = ToRegister(instr->function());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
  
    // If the receiver is null or undefined, we have to pass the global
    // object as a receiver to normal functions. Values have to be
    // passed unchanged to builtins and strict-mode functions.
    Label global_object, result_in_receiver;
  
    if (!instr->hydrogen()->known_function()) {
      // Do not transform the receiver to object for strict mode
      // functions or builtins.
      __ LoadP(scratch,
               FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
      __ lwz(scratch,
             FieldMemOperand(scratch, SharedFunctionInfo::kCompilerHintsOffset));
      __ andi(r0, scratch, Operand((1 << SharedFunctionInfo::kStrictModeBit) |
                                   (1 << SharedFunctionInfo::kNativeBit)));
      __ bne(&result_in_receiver, cr0);
    }
  
    // Normal function. Replace undefined or null with global receiver.
    __ LoadRoot(scratch, Heap::kNullValueRootIndex);
    __ cmp(receiver, scratch);
    __ beq(&global_object);
    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
    __ cmp(receiver, scratch);
    __ beq(&global_object);
  
    // Deoptimize if the receiver is not a JS object.
    __ TestIfSmi(receiver, r0);
    DeoptimizeIf(eq, instr, Deoptimizer::kSmi, cr0);
    __ CompareObjectType(receiver, scratch, scratch, FIRST_JS_RECEIVER_TYPE);
    DeoptimizeIf(lt, instr, Deoptimizer::kNotAJavaScriptObject);
  
    __ b(&result_in_receiver);
    __ bind(&global_object);
    __ LoadP(result, FieldMemOperand(function, JSFunction::kContextOffset));
    __ LoadP(result, ContextMemOperand(result, Context::NATIVE_CONTEXT_INDEX));
    __ LoadP(result, ContextMemOperand(result, Context::GLOBAL_PROXY_INDEX));
  
    if (result.is(receiver)) {
      __ bind(&result_in_receiver);
    } else {
      Label result_ok;
      __ b(&result_ok);
      __ bind(&result_in_receiver);
      __ mr(result, receiver);
      __ bind(&result_ok);
    }
  }
  
  
  void LCodeGen::DoApplyArguments(LApplyArguments* instr) {
    Register receiver = ToRegister(instr->receiver());
    Register function = ToRegister(instr->function());
    Register length = ToRegister(instr->length());
    Register elements = ToRegister(instr->elements());
    Register scratch = scratch0();
    DCHECK(receiver.is(r3));  // Used for parameter count.
    DCHECK(function.is(r4));  // Required by InvokeFunction.
    DCHECK(ToRegister(instr->result()).is(r3));
  
    // Copy the arguments to this function possibly from the
    // adaptor frame below it.
    const uint32_t kArgumentsLimit = 1 * KB;
    __ cmpli(length, Operand(kArgumentsLimit));
    DeoptimizeIf(gt, instr, Deoptimizer::kTooManyArguments);
  
    // Push the receiver and use the register to keep the original
    // number of arguments.
    __ push(receiver);
    __ mr(receiver, length);
    // The arguments are at a one pointer size offset from elements.
    __ addi(elements, elements, Operand(1 * kPointerSize));
  
    // Loop through the arguments pushing them onto the execution
    // stack.
    Label invoke, loop;
    // length is a small non-negative integer, due to the test above.
    __ cmpi(length, Operand::Zero());
    __ beq(&invoke);
    __ mtctr(length);
    __ bind(&loop);
    __ ShiftLeftImm(r0, length, Operand(kPointerSizeLog2));
    __ LoadPX(scratch, MemOperand(elements, r0));
    __ push(scratch);
    __ addi(length, length, Operand(-1));
    __ bdnz(&loop);
  
    __ bind(&invoke);
    DCHECK(instr->HasPointerMap());
    LPointerMap* pointers = instr->pointer_map();
    SafepointGenerator safepoint_generator(this, pointers, Safepoint::kLazyDeopt);
    // The number of arguments is stored in receiver which is r3, as expected
    // by InvokeFunction.
    ParameterCount actual(receiver);
    __ InvokeFunction(function, no_reg, actual, CALL_FUNCTION,
                      safepoint_generator);
  }
  
  
  void LCodeGen::DoPushArgument(LPushArgument* instr) {
    LOperand* argument = instr->value();
    if (argument->IsDoubleRegister() || argument->IsDoubleStackSlot()) {
      Abort(kDoPushArgumentNotImplementedForDoubleType);
    } else {
      Register argument_reg = EmitLoadRegister(argument, ip);
      __ push(argument_reg);
    }
  }
  
  
  void LCodeGen::DoDrop(LDrop* instr) { __ Drop(instr->count()); }
  
  
  void LCodeGen::DoThisFunction(LThisFunction* instr) {
    Register result = ToRegister(instr->result());
    __ LoadP(result, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
  }
  
  
  void LCodeGen::DoContext(LContext* instr) {
    // If there is a non-return use, the context must be moved to a register.
    Register result = ToRegister(instr->result());
    if (info()->IsOptimizing()) {
      __ LoadP(result, MemOperand(fp, StandardFrameConstants::kContextOffset));
    } else {
      // If there is no frame, the context must be in cp.
      DCHECK(result.is(cp));
    }
  }
  
  
  void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    __ Move(scratch0(), instr->hydrogen()->pairs());
    __ push(scratch0());
    __ LoadSmiLiteral(scratch0(), Smi::FromInt(instr->hydrogen()->flags()));
    __ push(scratch0());
    CallRuntime(Runtime::kDeclareGlobals, instr);
  }
  
  
  void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
                                   int formal_parameter_count, int arity,
                                   LInstruction* instr) {
    bool dont_adapt_arguments =
        formal_parameter_count == SharedFunctionInfo::kDontAdaptArgumentsSentinel;
    bool can_invoke_directly =
        dont_adapt_arguments || formal_parameter_count == arity;
  
    Register function_reg = r4;
  
    LPointerMap* pointers = instr->pointer_map();
  
    if (can_invoke_directly) {
      // Change context.
      __ LoadP(cp, FieldMemOperand(function_reg, JSFunction::kContextOffset));
  
      // Always initialize new target and number of actual arguments.
      __ LoadRoot(r6, Heap::kUndefinedValueRootIndex);
      __ mov(r3, Operand(arity));
  
      bool is_self_call = function.is_identical_to(info()->closure());
  
      // Invoke function.
      if (is_self_call) {
        __ CallSelf();
      } else {
        __ LoadP(ip, FieldMemOperand(function_reg, JSFunction::kCodeEntryOffset));
        __ CallJSEntry(ip);
      }
  
      // Set up deoptimization.
      RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
    } else {
      SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
      ParameterCount count(arity);
      ParameterCount expected(formal_parameter_count);
      __ InvokeFunction(function_reg, expected, count, CALL_FUNCTION, generator);
    }
  }
  
  
  void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr) {
    DCHECK(instr->context() != NULL);
    DCHECK(ToRegister(instr->context()).is(cp));
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
  
    // Deoptimize if not a heap number.
    __ LoadP(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
    __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
    __ cmp(scratch, ip);
    DeoptimizeIf(ne, instr, Deoptimizer::kNotAHeapNumber);
  
    Label done;
    Register exponent = scratch0();
    scratch = no_reg;
    __ lwz(exponent, FieldMemOperand(input, HeapNumber::kExponentOffset));
    // Check the sign of the argument. If the argument is positive, just
    // return it.
    __ cmpwi(exponent, Operand::Zero());
    // Move the input to the result if necessary.
    __ Move(result, input);
    __ bge(&done);
  
    // Input is negative. Reverse its sign.
    // Preserve the value of all registers.
    {
      PushSafepointRegistersScope scope(this);
  
      // Registers were saved at the safepoint, so we can use
      // many scratch registers.
      Register tmp1 = input.is(r4) ? r3 : r4;
      Register tmp2 = input.is(r5) ? r3 : r5;
      Register tmp3 = input.is(r6) ? r3 : r6;
      Register tmp4 = input.is(r7) ? r3 : r7;
  
      // exponent: floating point exponent value.
  
      Label allocated, slow;
      __ LoadRoot(tmp4, Heap::kHeapNumberMapRootIndex);
      __ AllocateHeapNumber(tmp1, tmp2, tmp3, tmp4, &slow);
      __ b(&allocated);
  
      // Slow case: Call the runtime system to do the number allocation.
      __ bind(&slow);
  
      CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr,
                              instr->context());
      // Set the pointer to the new heap number in tmp.
      if (!tmp1.is(r3)) __ mr(tmp1, r3);
      // Restore input_reg after call to runtime.
      __ LoadFromSafepointRegisterSlot(input, input);
      __ lwz(exponent, FieldMemOperand(input, HeapNumber::kExponentOffset));
  
      __ bind(&allocated);
      // exponent: floating point exponent value.
      // tmp1: allocated heap number.
      STATIC_ASSERT(HeapNumber::kSignMask == 0x80000000u);
      __ clrlwi(exponent, exponent, Operand(1));  // clear sign bit
      __ stw(exponent, FieldMemOperand(tmp1, HeapNumber::kExponentOffset));
      __ lwz(tmp2, FieldMemOperand(input, HeapNumber::kMantissaOffset));
      __ stw(tmp2, FieldMemOperand(tmp1, HeapNumber::kMantissaOffset));
  
      __ StoreToSafepointRegisterSlot(tmp1, result);
    }
  
    __ bind(&done);
  }
  
  
  void LCodeGen::EmitMathAbs(LMathAbs* instr) {
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
    Label done;
    __ cmpi(input, Operand::Zero());
    __ Move(result, input);
    __ bge(&done);
    __ li(r0, Operand::Zero());  // clear xer
    __ mtxer(r0);
    __ neg(result, result, SetOE, SetRC);
    // Deoptimize on overflow.
    DeoptimizeIf(overflow, instr, Deoptimizer::kOverflow, cr0);
    __ bind(&done);
  }
  
  
  #if V8_TARGET_ARCH_PPC64
  void LCodeGen::EmitInteger32MathAbs(LMathAbs* instr) {
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
    Label done;
    __ cmpwi(input, Operand::Zero());
    __ Move(result, input);
    __ bge(&done);
  
    // Deoptimize on overflow.
    __ lis(r0, Operand(SIGN_EXT_IMM16(0x8000)));
    __ cmpw(input, r0);
    DeoptimizeIf(eq, instr, Deoptimizer::kOverflow);
  
    __ neg(result, result);
    __ bind(&done);
  }
  #endif
  
  
  void LCodeGen::DoMathAbs(LMathAbs* instr) {
    // Class for deferred case.
    class DeferredMathAbsTaggedHeapNumber final : public LDeferredCode {
     public:
      DeferredMathAbsTaggedHeapNumber(LCodeGen* codegen, LMathAbs* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override {
        codegen()->DoDeferredMathAbsTaggedHeapNumber(instr_);
      }
      LInstruction* instr() override { return instr_; }
  
     private:
      LMathAbs* instr_;
    };
  
    Representation r = instr->hydrogen()->value()->representation();
    if (r.IsDouble()) {
      DoubleRegister input = ToDoubleRegister(instr->value());
      DoubleRegister result = ToDoubleRegister(instr->result());
      __ fabs(result, input);
  #if V8_TARGET_ARCH_PPC64
    } else if (r.IsInteger32()) {
      EmitInteger32MathAbs(instr);
    } else if (r.IsSmi()) {
  #else
    } else if (r.IsSmiOrInteger32()) {
  #endif
      EmitMathAbs(instr);
    } else {
      // Representation is tagged.
      DeferredMathAbsTaggedHeapNumber* deferred =
          new (zone()) DeferredMathAbsTaggedHeapNumber(this, instr);
      Register input = ToRegister(instr->value());
      // Smi check.
      __ JumpIfNotSmi(input, deferred->entry());
      // If smi, handle it directly.
      EmitMathAbs(instr);
      __ bind(deferred->exit());
    }
  }
  
  
  void LCodeGen::DoMathFloor(LMathFloor* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    Register result = ToRegister(instr->result());
    Register input_high = scratch0();
    Register scratch = ip;
    Label done, exact;
  
    __ TryInt32Floor(result, input, input_high, scratch, double_scratch0(), &done,
                     &exact);
    DeoptimizeIf(al, instr, Deoptimizer::kLostPrecisionOrNaN);
  
    __ bind(&exact);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      // Test for -0.
      __ cmpi(result, Operand::Zero());
      __ bne(&done);
      __ cmpwi(input_high, Operand::Zero());
      DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
    }
    __ bind(&done);
  }
  
  
  void LCodeGen::DoMathRound(LMathRound* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    Register result = ToRegister(instr->result());
    DoubleRegister double_scratch1 = ToDoubleRegister(instr->temp());
    DoubleRegister input_plus_dot_five = double_scratch1;
    Register scratch1 = scratch0();
    Register scratch2 = ip;
    DoubleRegister dot_five = double_scratch0();
    Label convert, done;
  
    __ LoadDoubleLiteral(dot_five, 0.5, r0);
    __ fabs(double_scratch1, input);
    __ fcmpu(double_scratch1, dot_five);
    DeoptimizeIf(unordered, instr, Deoptimizer::kLostPrecisionOrNaN);
    // If input is in [-0.5, -0], the result is -0.
    // If input is in [+0, +0.5[, the result is +0.
    // If the input is +0.5, the result is 1.
    __ bgt(&convert);  // Out of [-0.5, +0.5].
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
  #if V8_TARGET_ARCH_PPC64
      __ MovDoubleToInt64(scratch1, input);
  #else
      __ MovDoubleHighToInt(scratch1, input);
  #endif
      __ cmpi(scratch1, Operand::Zero());
      // [-0.5, -0].
      DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
    }
    __ fcmpu(input, dot_five);
    if (CpuFeatures::IsSupported(ISELECT)) {
      __ li(result, Operand(1));
      __ isel(lt, result, r0, result);
      __ b(&done);
    } else {
      Label return_zero;
      __ bne(&return_zero);
      __ li(result, Operand(1));  // +0.5.
      __ b(&done);
      // Remaining cases: [+0, +0.5[ or [-0.5, +0.5[, depending on
      // flag kBailoutOnMinusZero.
      __ bind(&return_zero);
      __ li(result, Operand::Zero());
      __ b(&done);
    }
  
    __ bind(&convert);
    __ fadd(input_plus_dot_five, input, dot_five);
    // Reuse dot_five (double_scratch0) as we no longer need this value.
    __ TryInt32Floor(result, input_plus_dot_five, scratch1, scratch2,
                     double_scratch0(), &done, &done);
    DeoptimizeIf(al, instr, Deoptimizer::kLostPrecisionOrNaN);
    __ bind(&done);
  }
  
  
  void LCodeGen::DoMathFround(LMathFround* instr) {
    DoubleRegister input_reg = ToDoubleRegister(instr->value());
    DoubleRegister output_reg = ToDoubleRegister(instr->result());
    __ frsp(output_reg, input_reg);
  }
  
  
  void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    __ fsqrt(result, input);
  }
  
  
  void LCodeGen::DoMathPowHalf(LMathPowHalf* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    DoubleRegister temp = double_scratch0();
  
    // Note that according to ECMA-262 15.8.2.13:
    // Math.pow(-Infinity, 0.5) == Infinity
    // Math.sqrt(-Infinity) == NaN
    Label skip, done;
  
    __ LoadDoubleLiteral(temp, -V8_INFINITY, scratch0());
    __ fcmpu(input, temp);
    __ bne(&skip);
    __ fneg(result, temp);
    __ b(&done);
  
    // Add +0 to convert -0 to +0.
    __ bind(&skip);
    __ fadd(result, input, kDoubleRegZero);
    __ fsqrt(result, result);
    __ bind(&done);
  }
  
  
  void LCodeGen::DoPower(LPower* instr) {
    Representation exponent_type = instr->hydrogen()->right()->representation();
  // Having marked this as a call, we can use any registers.
  // Just make sure that the input/output registers are the expected ones.
    Register tagged_exponent = MathPowTaggedDescriptor::exponent();
    DCHECK(!instr->right()->IsDoubleRegister() ||
           ToDoubleRegister(instr->right()).is(d2));
    DCHECK(!instr->right()->IsRegister() ||
           ToRegister(instr->right()).is(tagged_exponent));
    DCHECK(ToDoubleRegister(instr->left()).is(d1));
    DCHECK(ToDoubleRegister(instr->result()).is(d3));
  
    if (exponent_type.IsSmi()) {
      MathPowStub stub(isolate(), MathPowStub::TAGGED);
      __ CallStub(&stub);
    } else if (exponent_type.IsTagged()) {
      Label no_deopt;
      __ JumpIfSmi(tagged_exponent, &no_deopt);
      DCHECK(!r10.is(tagged_exponent));
      __ LoadP(r10, FieldMemOperand(tagged_exponent, HeapObject::kMapOffset));
      __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
      __ cmp(r10, ip);
      DeoptimizeIf(ne, instr, Deoptimizer::kNotAHeapNumber);
      __ bind(&no_deopt);
      MathPowStub stub(isolate(), MathPowStub::TAGGED);
      __ CallStub(&stub);
    } else if (exponent_type.IsInteger32()) {
      MathPowStub stub(isolate(), MathPowStub::INTEGER);
      __ CallStub(&stub);
    } else {
      DCHECK(exponent_type.IsDouble());
      MathPowStub stub(isolate(), MathPowStub::DOUBLE);
      __ CallStub(&stub);
    }
  }
  
  
  void LCodeGen::DoMathExp(LMathExp* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    DoubleRegister double_scratch1 = ToDoubleRegister(instr->double_temp());
    DoubleRegister double_scratch2 = double_scratch0();
    Register temp1 = ToRegister(instr->temp1());
    Register temp2 = ToRegister(instr->temp2());
  
    MathExpGenerator::EmitMathExp(masm(), input, result, double_scratch1,
                                  double_scratch2, temp1, temp2, scratch0());
  }
  
  
  void LCodeGen::DoMathLog(LMathLog* instr) {
    __ PrepareCallCFunction(0, 1, scratch0());
    __ MovToFloatParameter(ToDoubleRegister(instr->value()));
    __ CallCFunction(ExternalReference::math_log_double_function(isolate()), 0,
                     1);
    __ MovFromFloatResult(ToDoubleRegister(instr->result()));
  }
  
  
  void LCodeGen::DoMathClz32(LMathClz32* instr) {
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
    __ cntlzw_(result, input);
  }
  
  
  void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->function()).is(r4));
    DCHECK(instr->HasPointerMap());
  
    Handle<JSFunction> known_function = instr->hydrogen()->known_function();
    if (known_function.is_null()) {
      LPointerMap* pointers = instr->pointer_map();
      SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
      ParameterCount count(instr->arity());
      __ InvokeFunction(r4, no_reg, count, CALL_FUNCTION, generator);
    } else {
      CallKnownFunction(known_function,
                        instr->hydrogen()->formal_parameter_count(),
                        instr->arity(), instr);
    }
  }
  
  
  void LCodeGen::DoCallWithDescriptor(LCallWithDescriptor* instr) {
    DCHECK(ToRegister(instr->result()).is(r3));
  
    if (instr->hydrogen()->IsTailCall()) {
      if (NeedsEagerFrame()) __ LeaveFrame(StackFrame::INTERNAL);
  
      if (instr->target()->IsConstantOperand()) {
        LConstantOperand* target = LConstantOperand::cast(instr->target());
        Handle<Code> code = Handle<Code>::cast(ToHandle(target));
        __ Jump(code, RelocInfo::CODE_TARGET);
      } else {
        DCHECK(instr->target()->IsRegister());
        Register target = ToRegister(instr->target());
        __ addi(ip, target, Operand(Code::kHeaderSize - kHeapObjectTag));
        __ JumpToJSEntry(ip);
      }
    } else {
      LPointerMap* pointers = instr->pointer_map();
      SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
  
      if (instr->target()->IsConstantOperand()) {
        LConstantOperand* target = LConstantOperand::cast(instr->target());
        Handle<Code> code = Handle<Code>::cast(ToHandle(target));
        generator.BeforeCall(__ CallSize(code, RelocInfo::CODE_TARGET));
        __ Call(code, RelocInfo::CODE_TARGET);
      } else {
        DCHECK(instr->target()->IsRegister());
        Register target = ToRegister(instr->target());
        generator.BeforeCall(__ CallSize(target));
        __ addi(ip, target, Operand(Code::kHeaderSize - kHeapObjectTag));
        __ CallJSEntry(ip);
      }
      generator.AfterCall();
    }
  }
  
  
  void LCodeGen::DoCallJSFunction(LCallJSFunction* instr) {
    DCHECK(ToRegister(instr->function()).is(r4));
    DCHECK(ToRegister(instr->result()).is(r3));
  
    // Change context.
    __ LoadP(cp, FieldMemOperand(r4, JSFunction::kContextOffset));
  
    // Always initialize new target and number of actual arguments.
    __ LoadRoot(r6, Heap::kUndefinedValueRootIndex);
    __ mov(r3, Operand(instr->arity()));
  
    bool is_self_call = false;
    if (instr->hydrogen()->function()->IsConstant()) {
      HConstant* fun_const = HConstant::cast(instr->hydrogen()->function());
      Handle<JSFunction> jsfun =
          Handle<JSFunction>::cast(fun_const->handle(isolate()));
      is_self_call = jsfun.is_identical_to(info()->closure());
    }
  
    if (is_self_call) {
      __ CallSelf();
    } else {
      __ LoadP(ip, FieldMemOperand(r4, JSFunction::kCodeEntryOffset));
      __ CallJSEntry(ip);
    }
  
    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
  }
  
  
  void LCodeGen::DoCallFunction(LCallFunction* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->function()).is(r4));
    DCHECK(ToRegister(instr->result()).is(r3));
  
    int arity = instr->arity();
    ConvertReceiverMode mode = instr->hydrogen()->convert_mode();
    if (instr->hydrogen()->HasVectorAndSlot()) {
      Register slot_register = ToRegister(instr->temp_slot());
      Register vector_register = ToRegister(instr->temp_vector());
      DCHECK(slot_register.is(r6));
      DCHECK(vector_register.is(r5));
  
      AllowDeferredHandleDereference vector_structure_check;
      Handle<TypeFeedbackVector> vector = instr->hydrogen()->feedback_vector();
      int index = vector->GetIndex(instr->hydrogen()->slot());
  
      __ Move(vector_register, vector);
      __ LoadSmiLiteral(slot_register, Smi::FromInt(index));
  
      Handle<Code> ic =
          CodeFactory::CallICInOptimizedCode(isolate(), arity, mode).code();
      CallCode(ic, RelocInfo::CODE_TARGET, instr);
    } else {
      __ mov(r3, Operand(arity));
      CallCode(isolate()->builtins()->Call(mode), RelocInfo::CODE_TARGET, instr);
    }
  }
  
  
  void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->constructor()).is(r4));
    DCHECK(ToRegister(instr->result()).is(r3));
  
    __ mov(r3, Operand(instr->arity()));
    if (instr->arity() == 1) {
      // We only need the allocation site for the case we have a length argument.
      // The case may bail out to the runtime, which will determine the correct
      // elements kind with the site.
      __ Move(r5, instr->hydrogen()->site());
    } else {
      __ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
    }
    ElementsKind kind = instr->hydrogen()->elements_kind();
    AllocationSiteOverrideMode override_mode =
        (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE)
            ? DISABLE_ALLOCATION_SITES
            : DONT_OVERRIDE;
  
    if (instr->arity() == 0) {
      ArrayNoArgumentConstructorStub stub(isolate(), kind, override_mode);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    } else if (instr->arity() == 1) {
      Label done;
      if (IsFastPackedElementsKind(kind)) {
        Label packed_case;
        // We might need a change here
        // look at the first argument
        __ LoadP(r8, MemOperand(sp, 0));
        __ cmpi(r8, Operand::Zero());
        __ beq(&packed_case);
  
        ElementsKind holey_kind = GetHoleyElementsKind(kind);
        ArraySingleArgumentConstructorStub stub(isolate(), holey_kind,
                                                override_mode);
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        __ b(&done);
        __ bind(&packed_case);
      }
  
      ArraySingleArgumentConstructorStub stub(isolate(), kind, override_mode);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      __ bind(&done);
    } else {
      ArrayNArgumentsConstructorStub stub(isolate(), kind, override_mode);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    }
  }
  
  
  void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
    CallRuntime(instr->function(), instr->arity(), instr);
  }
  
  
  void LCodeGen::DoStoreCodeEntry(LStoreCodeEntry* instr) {
    Register function = ToRegister(instr->function());
    Register code_object = ToRegister(instr->code_object());
    __ addi(code_object, code_object,
            Operand(Code::kHeaderSize - kHeapObjectTag));
    __ StoreP(code_object,
              FieldMemOperand(function, JSFunction::kCodeEntryOffset), r0);
  }
  
  
  void LCodeGen::DoInnerAllocatedObject(LInnerAllocatedObject* instr) {
    Register result = ToRegister(instr->result());
    Register base = ToRegister(instr->base_object());
    if (instr->offset()->IsConstantOperand()) {
      LConstantOperand* offset = LConstantOperand::cast(instr->offset());
      __ Add(result, base, ToInteger32(offset), r0);
    } else {
      Register offset = ToRegister(instr->offset());
      __ add(result, base, offset);
    }
  }
  
  
  void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
    HStoreNamedField* hinstr = instr->hydrogen();
    Representation representation = instr->representation();
  
    Register object = ToRegister(instr->object());
    Register scratch = scratch0();
    HObjectAccess access = hinstr->access();
    int offset = access.offset();
  
    if (access.IsExternalMemory()) {
      Register value = ToRegister(instr->value());
      MemOperand operand = MemOperand(object, offset);
      __ StoreRepresentation(value, operand, representation, r0);
      return;
    }
  
    __ AssertNotSmi(object);
  
  #if V8_TARGET_ARCH_PPC64
    DCHECK(!representation.IsSmi() || !instr->value()->IsConstantOperand() ||
           IsInteger32(LConstantOperand::cast(instr->value())));
  #else
    DCHECK(!representation.IsSmi() || !instr->value()->IsConstantOperand() ||
           IsSmi(LConstantOperand::cast(instr->value())));
  #endif
    if (!FLAG_unbox_double_fields && representation.IsDouble()) {
      DCHECK(access.IsInobject());
      DCHECK(!hinstr->has_transition());
      DCHECK(!hinstr->NeedsWriteBarrier());
      DoubleRegister value = ToDoubleRegister(instr->value());
      __ stfd(value, FieldMemOperand(object, offset));
      return;
    }
  
    if (hinstr->has_transition()) {
      Handle<Map> transition = hinstr->transition_map();
      AddDeprecationDependency(transition);
      __ mov(scratch, Operand(transition));
      __ StoreP(scratch, FieldMemOperand(object, HeapObject::kMapOffset), r0);
      if (hinstr->NeedsWriteBarrierForMap()) {
        Register temp = ToRegister(instr->temp());
        // Update the write barrier for the map field.
        __ RecordWriteForMap(object, scratch, temp, GetLinkRegisterState(),
                             kSaveFPRegs);
      }
    }
  
    // Do the store.
    Register record_dest = object;
    Register record_value = no_reg;
    Register record_scratch = scratch;
  #if V8_TARGET_ARCH_PPC64
    if (FLAG_unbox_double_fields && representation.IsDouble()) {
      DCHECK(access.IsInobject());
      DoubleRegister value = ToDoubleRegister(instr->value());
      __ stfd(value, FieldMemOperand(object, offset));
      if (hinstr->NeedsWriteBarrier()) {
        record_value = ToRegister(instr->value());
      }
    } else {
      if (representation.IsSmi() &&
          hinstr->value()->representation().IsInteger32()) {
        DCHECK(hinstr->store_mode() == STORE_TO_INITIALIZED_ENTRY);
        // 64-bit Smi optimization
        // Store int value directly to upper half of the smi.
        offset = SmiWordOffset(offset);
        representation = Representation::Integer32();
      }
  #endif
      if (access.IsInobject()) {
        Register value = ToRegister(instr->value());
        MemOperand operand = FieldMemOperand(object, offset);
        __ StoreRepresentation(value, operand, representation, r0);
        record_value = value;
      } else {
        Register value = ToRegister(instr->value());
        __ LoadP(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
        MemOperand operand = FieldMemOperand(scratch, offset);
        __ StoreRepresentation(value, operand, representation, r0);
        record_dest = scratch;
        record_value = value;
        record_scratch = object;
      }
  #if V8_TARGET_ARCH_PPC64
    }
  #endif
  
    if (hinstr->NeedsWriteBarrier()) {
      __ RecordWriteField(record_dest, offset, record_value, record_scratch,
                          GetLinkRegisterState(), kSaveFPRegs,
                          EMIT_REMEMBERED_SET, hinstr->SmiCheckForWriteBarrier(),
                          hinstr->PointersToHereCheckForValue());
    }
  }
  
  
  void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->object()).is(StoreDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
  
    if (instr->hydrogen()->HasVectorAndSlot()) {
      EmitVectorStoreICRegisters<LStoreNamedGeneric>(instr);
    }
  
    __ mov(StoreDescriptor::NameRegister(), Operand(instr->name()));
    Handle<Code> ic = CodeFactory::StoreICInOptimizedCode(
                          isolate(), instr->language_mode(),
                          instr->hydrogen()->initialization_state()).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
    Representation representation = instr->hydrogen()->length()->representation();
    DCHECK(representation.Equals(instr->hydrogen()->index()->representation()));
    DCHECK(representation.IsSmiOrInteger32());
  
    Condition cc = instr->hydrogen()->allow_equality() ? lt : le;
    if (instr->length()->IsConstantOperand()) {
      int32_t length = ToInteger32(LConstantOperand::cast(instr->length()));
      Register index = ToRegister(instr->index());
      if (representation.IsSmi()) {
        __ Cmpli(index, Operand(Smi::FromInt(length)), r0);
      } else {
        __ Cmplwi(index, Operand(length), r0);
      }
      cc = CommuteCondition(cc);
    } else if (instr->index()->IsConstantOperand()) {
      int32_t index = ToInteger32(LConstantOperand::cast(instr->index()));
      Register length = ToRegister(instr->length());
      if (representation.IsSmi()) {
        __ Cmpli(length, Operand(Smi::FromInt(index)), r0);
      } else {
        __ Cmplwi(length, Operand(index), r0);
      }
    } else {
      Register index = ToRegister(instr->index());
      Register length = ToRegister(instr->length());
      if (representation.IsSmi()) {
        __ cmpl(length, index);
      } else {
        __ cmplw(length, index);
      }
    }
    if (FLAG_debug_code && instr->hydrogen()->skip_check()) {
      Label done;
      __ b(NegateCondition(cc), &done);
      __ stop("eliminated bounds check failed");
      __ bind(&done);
    } else {
      DeoptimizeIf(cc, instr, Deoptimizer::kOutOfBounds);
    }
  }
  
  
  void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
    Register external_pointer = ToRegister(instr->elements());
    Register key = no_reg;
    ElementsKind elements_kind = instr->elements_kind();
    bool key_is_constant = instr->key()->IsConstantOperand();
    int constant_key = 0;
    if (key_is_constant) {
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xF0000000) {
        Abort(kArrayIndexConstantValueTooBig);
      }
    } else {
      key = ToRegister(instr->key());
    }
    int element_size_shift = ElementsKindToShiftSize(elements_kind);
    bool key_is_smi = instr->hydrogen()->key()->representation().IsSmi();
    int base_offset = instr->base_offset();
  
    if (elements_kind == FLOAT32_ELEMENTS || elements_kind == FLOAT64_ELEMENTS) {
      Register address = scratch0();
      DoubleRegister value(ToDoubleRegister(instr->value()));
      if (key_is_constant) {
        if (constant_key != 0) {
          __ Add(address, external_pointer, constant_key << element_size_shift,
                 r0);
        } else {
          address = external_pointer;
        }
      } else {
        __ IndexToArrayOffset(r0, key, element_size_shift, key_is_smi);
        __ add(address, external_pointer, r0);
      }
      if (elements_kind == FLOAT32_ELEMENTS) {
        __ frsp(double_scratch0(), value);
        __ stfs(double_scratch0(), MemOperand(address, base_offset));
      } else {  // Storing doubles, not floats.
        __ stfd(value, MemOperand(address, base_offset));
      }
    } else {
      Register value(ToRegister(instr->value()));
      MemOperand mem_operand =
          PrepareKeyedOperand(key, external_pointer, key_is_constant, key_is_smi,
                              constant_key, element_size_shift, base_offset);
      switch (elements_kind) {
        case UINT8_ELEMENTS:
        case UINT8_CLAMPED_ELEMENTS:
        case INT8_ELEMENTS:
          if (key_is_constant) {
            __ StoreByte(value, mem_operand, r0);
          } else {
            __ stbx(value, mem_operand);
          }
          break;
        case INT16_ELEMENTS:
        case UINT16_ELEMENTS:
          if (key_is_constant) {
            __ StoreHalfWord(value, mem_operand, r0);
          } else {
            __ sthx(value, mem_operand);
          }
          break;
        case INT32_ELEMENTS:
        case UINT32_ELEMENTS:
          if (key_is_constant) {
            __ StoreWord(value, mem_operand, r0);
          } else {
            __ stwx(value, mem_operand);
          }
          break;
        case FLOAT32_ELEMENTS:
        case FLOAT64_ELEMENTS:
        case FAST_DOUBLE_ELEMENTS:
        case FAST_ELEMENTS:
        case FAST_SMI_ELEMENTS:
        case FAST_HOLEY_DOUBLE_ELEMENTS:
        case FAST_HOLEY_ELEMENTS:
        case FAST_HOLEY_SMI_ELEMENTS:
        case DICTIONARY_ELEMENTS:
        case FAST_SLOPPY_ARGUMENTS_ELEMENTS:
        case SLOW_SLOPPY_ARGUMENTS_ELEMENTS:
          UNREACHABLE();
          break;
      }
    }
  }
  
  
  void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
    DoubleRegister value = ToDoubleRegister(instr->value());
    Register elements = ToRegister(instr->elements());
    Register key = no_reg;
    Register scratch = scratch0();
    DoubleRegister double_scratch = double_scratch0();
    bool key_is_constant = instr->key()->IsConstantOperand();
    int constant_key = 0;
  
    // Calculate the effective address of the slot in the array to store the
    // double value.
    if (key_is_constant) {
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xF0000000) {
        Abort(kArrayIndexConstantValueTooBig);
      }
    } else {
      key = ToRegister(instr->key());
    }
    int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
    bool key_is_smi = instr->hydrogen()->key()->representation().IsSmi();
    int base_offset = instr->base_offset() + constant_key * kDoubleSize;
    if (!key_is_constant) {
      __ IndexToArrayOffset(scratch, key, element_size_shift, key_is_smi);
      __ add(scratch, elements, scratch);
      elements = scratch;
    }
    if (!is_int16(base_offset)) {
      __ Add(scratch, elements, base_offset, r0);
      base_offset = 0;
      elements = scratch;
    }
  
    if (instr->NeedsCanonicalization()) {
      // Turn potential sNaN value into qNaN.
      __ CanonicalizeNaN(double_scratch, value);
      __ stfd(double_scratch, MemOperand(elements, base_offset));
    } else {
      __ stfd(value, MemOperand(elements, base_offset));
    }
  }
  
  
  void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
    HStoreKeyed* hinstr = instr->hydrogen();
    Register value = ToRegister(instr->value());
    Register elements = ToRegister(instr->elements());
    Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
    Register scratch = scratch0();
    Register store_base = scratch;
    int offset = instr->base_offset();
  
    // Do the store.
    if (instr->key()->IsConstantOperand()) {
      DCHECK(!hinstr->NeedsWriteBarrier());
      LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
      offset += ToInteger32(const_operand) * kPointerSize;
      store_base = elements;
    } else {
      // Even though the HLoadKeyed instruction forces the input
      // representation for the key to be an integer, the input gets replaced
      // during bound check elimination with the index argument to the bounds
      // check, which can be tagged, so that case must be handled here, too.
      if (hinstr->key()->representation().IsSmi()) {
        __ SmiToPtrArrayOffset(scratch, key);
      } else {
        __ ShiftLeftImm(scratch, key, Operand(kPointerSizeLog2));
      }
      __ add(scratch, elements, scratch);
    }
  
    Representation representation = hinstr->value()->representation();
  
  #if V8_TARGET_ARCH_PPC64
    // 64-bit Smi optimization
    if (representation.IsInteger32()) {
      DCHECK(hinstr->store_mode() == STORE_TO_INITIALIZED_ENTRY);
      DCHECK(hinstr->elements_kind() == FAST_SMI_ELEMENTS);
      // Store int value directly to upper half of the smi.
      offset = SmiWordOffset(offset);
    }
  #endif
  
    __ StoreRepresentation(value, MemOperand(store_base, offset), representation,
                           r0);
  
    if (hinstr->NeedsWriteBarrier()) {
      SmiCheck check_needed = hinstr->value()->type().IsHeapObject()
                                  ? OMIT_SMI_CHECK
                                  : INLINE_SMI_CHECK;
      // Compute address of modified element and store it into key register.
      __ Add(key, store_base, offset, r0);
      __ RecordWrite(elements, key, value, GetLinkRegisterState(), kSaveFPRegs,
                     EMIT_REMEMBERED_SET, check_needed,
                     hinstr->PointersToHereCheckForValue());
    }
  }
  
  
  void LCodeGen::DoStoreKeyed(LStoreKeyed* instr) {
    // By cases: external, fast double
    if (instr->is_fixed_typed_array()) {
      DoStoreKeyedExternalArray(instr);
    } else if (instr->hydrogen()->value()->representation().IsDouble()) {
      DoStoreKeyedFixedDoubleArray(instr);
    } else {
      DoStoreKeyedFixedArray(instr);
    }
  }
  
  
  void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->object()).is(StoreDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->key()).is(StoreDescriptor::NameRegister()));
    DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
  
    if (instr->hydrogen()->HasVectorAndSlot()) {
      EmitVectorStoreICRegisters<LStoreKeyedGeneric>(instr);
    }
  
    Handle<Code> ic = CodeFactory::KeyedStoreICInOptimizedCode(
                          isolate(), instr->language_mode(),
                          instr->hydrogen()->initialization_state()).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoMaybeGrowElements(LMaybeGrowElements* instr) {
    class DeferredMaybeGrowElements final : public LDeferredCode {
     public:
      DeferredMaybeGrowElements(LCodeGen* codegen, LMaybeGrowElements* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override { codegen()->DoDeferredMaybeGrowElements(instr_); }
      LInstruction* instr() override { return instr_; }
  
     private:
      LMaybeGrowElements* instr_;
    };
  
    Register result = r3;
    DeferredMaybeGrowElements* deferred =
        new (zone()) DeferredMaybeGrowElements(this, instr);
    LOperand* key = instr->key();
    LOperand* current_capacity = instr->current_capacity();
  
    DCHECK(instr->hydrogen()->key()->representation().IsInteger32());
    DCHECK(instr->hydrogen()->current_capacity()->representation().IsInteger32());
    DCHECK(key->IsConstantOperand() || key->IsRegister());
    DCHECK(current_capacity->IsConstantOperand() ||
           current_capacity->IsRegister());
  
    if (key->IsConstantOperand() && current_capacity->IsConstantOperand()) {
      int32_t constant_key = ToInteger32(LConstantOperand::cast(key));
      int32_t constant_capacity =
          ToInteger32(LConstantOperand::cast(current_capacity));
      if (constant_key >= constant_capacity) {
        // Deferred case.
        __ b(deferred->entry());
      }
    } else if (key->IsConstantOperand()) {
      int32_t constant_key = ToInteger32(LConstantOperand::cast(key));
      __ Cmpwi(ToRegister(current_capacity), Operand(constant_key), r0);
      __ ble(deferred->entry());
    } else if (current_capacity->IsConstantOperand()) {
      int32_t constant_capacity =
          ToInteger32(LConstantOperand::cast(current_capacity));
      __ Cmpwi(ToRegister(key), Operand(constant_capacity), r0);
      __ bge(deferred->entry());
    } else {
      __ cmpw(ToRegister(key), ToRegister(current_capacity));
      __ bge(deferred->entry());
    }
  
    if (instr->elements()->IsRegister()) {
      __ Move(result, ToRegister(instr->elements()));
    } else {
      __ LoadP(result, ToMemOperand(instr->elements()));
    }
  
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredMaybeGrowElements(LMaybeGrowElements* instr) {
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    Register result = r3;
    __ li(result, Operand::Zero());
  
    // We have to call a stub.
    {
      PushSafepointRegistersScope scope(this);
      if (instr->object()->IsRegister()) {
        __ Move(result, ToRegister(instr->object()));
      } else {
        __ LoadP(result, ToMemOperand(instr->object()));
      }
  
      LOperand* key = instr->key();
      if (key->IsConstantOperand()) {
        __ LoadSmiLiteral(r6, ToSmi(LConstantOperand::cast(key)));
      } else {
        __ SmiTag(r6, ToRegister(key));
      }
  
      GrowArrayElementsStub stub(isolate(), instr->hydrogen()->is_js_array(),
                                 instr->hydrogen()->kind());
      __ CallStub(&stub);
      RecordSafepointWithLazyDeopt(
          instr, RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
      __ StoreToSafepointRegisterSlot(result, result);
    }
  
    // Deopt on smi, which means the elements array changed to dictionary mode.
    __ TestIfSmi(result, r0);
    DeoptimizeIf(eq, instr, Deoptimizer::kSmi, cr0);
  }
  
  
  void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
    Register object_reg = ToRegister(instr->object());
    Register scratch = scratch0();
  
    Handle<Map> from_map = instr->original_map();
    Handle<Map> to_map = instr->transitioned_map();
    ElementsKind from_kind = instr->from_kind();
    ElementsKind to_kind = instr->to_kind();
  
    Label not_applicable;
    __ LoadP(scratch, FieldMemOperand(object_reg, HeapObject::kMapOffset));
    __ Cmpi(scratch, Operand(from_map), r0);
    __ bne(&not_applicable);
  
    if (IsSimpleMapChangeTransition(from_kind, to_kind)) {
      Register new_map_reg = ToRegister(instr->new_map_temp());
      __ mov(new_map_reg, Operand(to_map));
      __ StoreP(new_map_reg, FieldMemOperand(object_reg, HeapObject::kMapOffset),
                r0);
      // Write barrier.
      __ RecordWriteForMap(object_reg, new_map_reg, scratch,
                           GetLinkRegisterState(), kDontSaveFPRegs);
    } else {
      DCHECK(ToRegister(instr->context()).is(cp));
      DCHECK(object_reg.is(r3));
      PushSafepointRegistersScope scope(this);
      __ Move(r4, to_map);
      bool is_js_array = from_map->instance_type() == JS_ARRAY_TYPE;
      TransitionElementsKindStub stub(isolate(), from_kind, to_kind, is_js_array);
      __ CallStub(&stub);
      RecordSafepointWithRegisters(instr->pointer_map(), 0,
                                   Safepoint::kLazyDeopt);
    }
    __ bind(&not_applicable);
  }
  
  
  void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
    Register object = ToRegister(instr->object());
    Register temp = ToRegister(instr->temp());
    Label no_memento_found;
    __ TestJSArrayForAllocationMemento(object, temp, &no_memento_found);
    DeoptimizeIf(eq, instr, Deoptimizer::kMementoFound);
    __ bind(&no_memento_found);
  }
  
  
  void LCodeGen::DoStringAdd(LStringAdd* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->left()).is(r4));
    DCHECK(ToRegister(instr->right()).is(r3));
    StringAddStub stub(isolate(), instr->hydrogen()->flags(),
                       instr->hydrogen()->pretenure_flag());
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoStringCharCodeAt(LStringCharCodeAt* instr) {
    class DeferredStringCharCodeAt final : public LDeferredCode {
     public:
      DeferredStringCharCodeAt(LCodeGen* codegen, LStringCharCodeAt* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override { codegen()->DoDeferredStringCharCodeAt(instr_); }
      LInstruction* instr() override { return instr_; }
  
     private:
      LStringCharCodeAt* instr_;
    };
  
    DeferredStringCharCodeAt* deferred =
        new (zone()) DeferredStringCharCodeAt(this, instr);
  
    StringCharLoadGenerator::Generate(
        masm(), ToRegister(instr->string()), ToRegister(instr->index()),
        ToRegister(instr->result()), deferred->entry());
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredStringCharCodeAt(LStringCharCodeAt* instr) {
    Register string = ToRegister(instr->string());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
  
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    __ li(result, Operand::Zero());
  
    PushSafepointRegistersScope scope(this);
    __ push(string);
    // Push the index as a smi. This is safe because of the checks in
    // DoStringCharCodeAt above.
    if (instr->index()->IsConstantOperand()) {
      int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
      __ LoadSmiLiteral(scratch, Smi::FromInt(const_index));
      __ push(scratch);
    } else {
      Register index = ToRegister(instr->index());
      __ SmiTag(index);
      __ push(index);
    }
    CallRuntimeFromDeferred(Runtime::kStringCharCodeAtRT, 2, instr,
                            instr->context());
    __ AssertSmi(r3);
    __ SmiUntag(r3);
    __ StoreToSafepointRegisterSlot(r3, result);
  }
  
  
  void LCodeGen::DoStringCharFromCode(LStringCharFromCode* instr) {
    class DeferredStringCharFromCode final : public LDeferredCode {
     public:
      DeferredStringCharFromCode(LCodeGen* codegen, LStringCharFromCode* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override {
        codegen()->DoDeferredStringCharFromCode(instr_);
      }
      LInstruction* instr() override { return instr_; }
  
     private:
      LStringCharFromCode* instr_;
    };
  
    DeferredStringCharFromCode* deferred =
        new (zone()) DeferredStringCharFromCode(this, instr);
  
    DCHECK(instr->hydrogen()->value()->representation().IsInteger32());
    Register char_code = ToRegister(instr->char_code());
    Register result = ToRegister(instr->result());
    DCHECK(!char_code.is(result));
  
    __ cmpli(char_code, Operand(String::kMaxOneByteCharCode));
    __ bgt(deferred->entry());
    __ LoadRoot(result, Heap::kSingleCharacterStringCacheRootIndex);
    __ ShiftLeftImm(r0, char_code, Operand(kPointerSizeLog2));
    __ add(result, result, r0);
    __ LoadP(result, FieldMemOperand(result, FixedArray::kHeaderSize));
    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
    __ cmp(result, ip);
    __ beq(deferred->entry());
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredStringCharFromCode(LStringCharFromCode* instr) {
    Register char_code = ToRegister(instr->char_code());
    Register result = ToRegister(instr->result());
  
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    __ li(result, Operand::Zero());
  
    PushSafepointRegistersScope scope(this);
    __ SmiTag(char_code);
    __ push(char_code);
    CallRuntimeFromDeferred(Runtime::kStringCharFromCode, 1, instr,
                            instr->context());
    __ StoreToSafepointRegisterSlot(r3, result);
  }
  
  
  void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
    LOperand* input = instr->value();
    DCHECK(input->IsRegister() || input->IsStackSlot());
    LOperand* output = instr->result();
    DCHECK(output->IsDoubleRegister());
    if (input->IsStackSlot()) {
      Register scratch = scratch0();
      __ LoadP(scratch, ToMemOperand(input));
      __ ConvertIntToDouble(scratch, ToDoubleRegister(output));
    } else {
      __ ConvertIntToDouble(ToRegister(input), ToDoubleRegister(output));
    }
  }
  
  
  void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
    LOperand* input = instr->value();
    LOperand* output = instr->result();
    __ ConvertUnsignedIntToDouble(ToRegister(input), ToDoubleRegister(output));
  }
  
  
  void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
    class DeferredNumberTagI final : public LDeferredCode {
     public:
      DeferredNumberTagI(LCodeGen* codegen, LNumberTagI* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override {
        codegen()->DoDeferredNumberTagIU(instr_, instr_->value(), instr_->temp1(),
                                         instr_->temp2(), SIGNED_INT32);
      }
      LInstruction* instr() override { return instr_; }
  
     private:
      LNumberTagI* instr_;
    };
  
    Register src = ToRegister(instr->value());
    Register dst = ToRegister(instr->result());
  
    DeferredNumberTagI* deferred = new (zone()) DeferredNumberTagI(this, instr);
  #if V8_TARGET_ARCH_PPC64
    __ SmiTag(dst, src);
  #else
    __ SmiTagCheckOverflow(dst, src, r0);
    __ BranchOnOverflow(deferred->entry());
  #endif
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoNumberTagU(LNumberTagU* instr) {
    class DeferredNumberTagU final : public LDeferredCode {
     public:
      DeferredNumberTagU(LCodeGen* codegen, LNumberTagU* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override {
        codegen()->DoDeferredNumberTagIU(instr_, instr_->value(), instr_->temp1(),
                                         instr_->temp2(), UNSIGNED_INT32);
      }
      LInstruction* instr() override { return instr_; }
  
     private:
      LNumberTagU* instr_;
    };
  
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
  
    DeferredNumberTagU* deferred = new (zone()) DeferredNumberTagU(this, instr);
    __ Cmpli(input, Operand(Smi::kMaxValue), r0);
    __ bgt(deferred->entry());
    __ SmiTag(result, input);
    __ bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredNumberTagIU(LInstruction* instr, LOperand* value,
                                       LOperand* temp1, LOperand* temp2,
                                       IntegerSignedness signedness) {
    Label done, slow;
    Register src = ToRegister(value);
    Register dst = ToRegister(instr->result());
    Register tmp1 = scratch0();
    Register tmp2 = ToRegister(temp1);
    Register tmp3 = ToRegister(temp2);
    DoubleRegister dbl_scratch = double_scratch0();
  
    if (signedness == SIGNED_INT32) {
      // There was overflow, so bits 30 and 31 of the original integer
      // disagree. Try to allocate a heap number in new space and store
      // the value in there. If that fails, call the runtime system.
      if (dst.is(src)) {
        __ SmiUntag(src, dst);
        __ xoris(src, src, Operand(HeapNumber::kSignMask >> 16));
      }
      __ ConvertIntToDouble(src, dbl_scratch);
    } else {
      __ ConvertUnsignedIntToDouble(src, dbl_scratch);
    }
  
    if (FLAG_inline_new) {
      __ LoadRoot(tmp3, Heap::kHeapNumberMapRootIndex);
      __ AllocateHeapNumber(dst, tmp1, tmp2, tmp3, &slow);
      __ b(&done);
    }
  
    // Slow case: Call the runtime system to do the number allocation.
    __ bind(&slow);
    {
      // TODO(3095996): Put a valid pointer value in the stack slot where the
      // result register is stored, as this register is in the pointer map, but
      // contains an integer value.
      __ li(dst, Operand::Zero());
  
      // Preserve the value of all registers.
      PushSafepointRegistersScope scope(this);
  
      // NumberTagI and NumberTagD use the context from the frame, rather than
      // the environment's HContext or HInlinedContext value.
      // They only call Runtime::kAllocateHeapNumber.
      // The corresponding HChange instructions are added in a phase that does
      // not have easy access to the local context.
      __ LoadP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
      __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
      RecordSafepointWithRegisters(instr->pointer_map(), 0,
                                   Safepoint::kNoLazyDeopt);
      __ StoreToSafepointRegisterSlot(r3, dst);
    }
  
    // Done. Put the value in dbl_scratch into the value of the allocated heap
    // number.
    __ bind(&done);
    __ stfd(dbl_scratch, FieldMemOperand(dst, HeapNumber::kValueOffset));
  }
  
  
  void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
    class DeferredNumberTagD final : public LDeferredCode {
     public:
      DeferredNumberTagD(LCodeGen* codegen, LNumberTagD* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override { codegen()->DoDeferredNumberTagD(instr_); }
      LInstruction* instr() override { return instr_; }
  
     private:
      LNumberTagD* instr_;
    };
  
    DoubleRegister input_reg = ToDoubleRegister(instr->value());
    Register scratch = scratch0();
    Register reg = ToRegister(instr->result());
    Register temp1 = ToRegister(instr->temp());
    Register temp2 = ToRegister(instr->temp2());
  
    DeferredNumberTagD* deferred = new (zone()) DeferredNumberTagD(this, instr);
    if (FLAG_inline_new) {
      __ LoadRoot(scratch, Heap::kHeapNumberMapRootIndex);
      __ AllocateHeapNumber(reg, temp1, temp2, scratch, deferred->entry());
    } else {
      __ b(deferred->entry());
    }
    __ bind(deferred->exit());
    __ stfd(input_reg, FieldMemOperand(reg, HeapNumber::kValueOffset));
  }
  
  
  void LCodeGen::DoDeferredNumberTagD(LNumberTagD* instr) {
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    Register reg = ToRegister(instr->result());
    __ li(reg, Operand::Zero());
  
    PushSafepointRegistersScope scope(this);
    // NumberTagI and NumberTagD use the context from the frame, rather than
    // the environment's HContext or HInlinedContext value.
    // They only call Runtime::kAllocateHeapNumber.
    // The corresponding HChange instructions are added in a phase that does
    // not have easy access to the local context.
    __ LoadP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
    __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
    RecordSafepointWithRegisters(instr->pointer_map(), 0,
                                 Safepoint::kNoLazyDeopt);
    __ StoreToSafepointRegisterSlot(r3, reg);
  }
  
  
  void LCodeGen::DoSmiTag(LSmiTag* instr) {
    HChange* hchange = instr->hydrogen();
    Register input = ToRegister(instr->value());
    Register output = ToRegister(instr->result());
    if (hchange->CheckFlag(HValue::kCanOverflow) &&
        hchange->value()->CheckFlag(HValue::kUint32)) {
      __ TestUnsignedSmiCandidate(input, r0);
      DeoptimizeIf(ne, instr, Deoptimizer::kOverflow, cr0);
    }
  #if !V8_TARGET_ARCH_PPC64
    if (hchange->CheckFlag(HValue::kCanOverflow) &&
        !hchange->value()->CheckFlag(HValue::kUint32)) {
      __ SmiTagCheckOverflow(output, input, r0);
      DeoptimizeIf(lt, instr, Deoptimizer::kOverflow, cr0);
    } else {
  #endif
      __ SmiTag(output, input);
  #if !V8_TARGET_ARCH_PPC64
    }
  #endif
  }
  
  
  void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
    Register scratch = scratch0();
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
    if (instr->needs_check()) {
      // If the input is a HeapObject, value of scratch won't be zero.
      __ andi(scratch, input, Operand(kHeapObjectTag));
      __ SmiUntag(result, input);
      DeoptimizeIf(ne, instr, Deoptimizer::kNotASmi, cr0);
    } else {
      __ SmiUntag(result, input);
    }
  }
  
  
  void LCodeGen::EmitNumberUntagD(LNumberUntagD* instr, Register input_reg,
                                  DoubleRegister result_reg,
                                  NumberUntagDMode mode) {
    bool can_convert_undefined_to_nan =
        instr->hydrogen()->can_convert_undefined_to_nan();
    bool deoptimize_on_minus_zero = instr->hydrogen()->deoptimize_on_minus_zero();
  
    Register scratch = scratch0();
    DCHECK(!result_reg.is(double_scratch0()));
  
    Label convert, load_smi, done;
  
    if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
      // Smi check.
      __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);
  
      // Heap number map check.
      __ LoadP(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
      __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
      __ cmp(scratch, ip);
      if (can_convert_undefined_to_nan) {
        __ bne(&convert);
      } else {
        DeoptimizeIf(ne, instr, Deoptimizer::kNotAHeapNumber);
      }
      // load heap number
      __ lfd(result_reg, FieldMemOperand(input_reg, HeapNumber::kValueOffset));
      if (deoptimize_on_minus_zero) {
  #if V8_TARGET_ARCH_PPC64
        __ MovDoubleToInt64(scratch, result_reg);
        // rotate left by one for simple compare.
        __ rldicl(scratch, scratch, 1, 0);
        __ cmpi(scratch, Operand(1));
  #else
        __ MovDoubleToInt64(scratch, ip, result_reg);
        __ cmpi(ip, Operand::Zero());
        __ bne(&done);
        __ Cmpi(scratch, Operand(HeapNumber::kSignMask), r0);
  #endif
        DeoptimizeIf(eq, instr, Deoptimizer::kMinusZero);
      }
      __ b(&done);
      if (can_convert_undefined_to_nan) {
        __ bind(&convert);
        // Convert undefined (and hole) to NaN.
        __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
        __ cmp(input_reg, ip);
        DeoptimizeIf(ne, instr, Deoptimizer::kNotAHeapNumberUndefined);
        __ LoadRoot(scratch, Heap::kNanValueRootIndex);
        __ lfd(result_reg, FieldMemOperand(scratch, HeapNumber::kValueOffset));
        __ b(&done);
      }
    } else {
      __ SmiUntag(scratch, input_reg);
      DCHECK(mode == NUMBER_CANDIDATE_IS_SMI);
    }
    // Smi to double register conversion
    __ bind(&load_smi);
    // scratch: untagged value of input_reg
    __ ConvertIntToDouble(scratch, result_reg);
    __ bind(&done);
  }
  
  
  void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
    Register input_reg = ToRegister(instr->value());
    Register scratch1 = scratch0();
    Register scratch2 = ToRegister(instr->temp());
    DoubleRegister double_scratch = double_scratch0();
    DoubleRegister double_scratch2 = ToDoubleRegister(instr->temp2());
  
    DCHECK(!scratch1.is(input_reg) && !scratch1.is(scratch2));
    DCHECK(!scratch2.is(input_reg) && !scratch2.is(scratch1));
  
    Label done;
  
    // Heap number map check.
    __ LoadP(scratch1, FieldMemOperand(input_reg, HeapObject::kMapOffset));
    __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
    __ cmp(scratch1, ip);
  
    if (instr->truncating()) {
      // Performs a truncating conversion of a floating point number as used by
      // the JS bitwise operations.
      Label no_heap_number, check_bools, check_false;
      __ bne(&no_heap_number);
      __ mr(scratch2, input_reg);
      __ TruncateHeapNumberToI(input_reg, scratch2);
      __ b(&done);
  
      // Check for Oddballs. Undefined/False is converted to zero and True to one
      // for truncating conversions.
      __ bind(&no_heap_number);
      __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
      __ cmp(input_reg, ip);
      __ bne(&check_bools);
      __ li(input_reg, Operand::Zero());
      __ b(&done);
  
      __ bind(&check_bools);
      __ LoadRoot(ip, Heap::kTrueValueRootIndex);
      __ cmp(input_reg, ip);
      __ bne(&check_false);
      __ li(input_reg, Operand(1));
      __ b(&done);
  
      __ bind(&check_false);
      __ LoadRoot(ip, Heap::kFalseValueRootIndex);
      __ cmp(input_reg, ip);
      DeoptimizeIf(ne, instr, Deoptimizer::kNotAHeapNumberUndefinedBoolean);
      __ li(input_reg, Operand::Zero());
    } else {
      DeoptimizeIf(ne, instr, Deoptimizer::kNotAHeapNumber);
  
      __ lfd(double_scratch2,
             FieldMemOperand(input_reg, HeapNumber::kValueOffset));
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        // preserve heap number pointer in scratch2 for minus zero check below
        __ mr(scratch2, input_reg);
      }
      __ TryDoubleToInt32Exact(input_reg, double_scratch2, scratch1,
                               double_scratch);
      DeoptimizeIf(ne, instr, Deoptimizer::kLostPrecisionOrNaN);
  
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        __ cmpi(input_reg, Operand::Zero());
        __ bne(&done);
        __ lwz(scratch1,
               FieldMemOperand(scratch2, HeapNumber::kValueOffset +
                                             Register::kExponentOffset));
        __ cmpwi(scratch1, Operand::Zero());
        DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
      }
    }
    __ bind(&done);
  }
  
  
  void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
    class DeferredTaggedToI final : public LDeferredCode {
     public:
      DeferredTaggedToI(LCodeGen* codegen, LTaggedToI* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override { codegen()->DoDeferredTaggedToI(instr_); }
      LInstruction* instr() override { return instr_; }
  
     private:
      LTaggedToI* instr_;
    };
  
    LOperand* input = instr->value();
    DCHECK(input->IsRegister());
    DCHECK(input->Equals(instr->result()));
  
    Register input_reg = ToRegister(input);
  
    if (instr->hydrogen()->value()->representation().IsSmi()) {
      __ SmiUntag(input_reg);
    } else {
      DeferredTaggedToI* deferred = new (zone()) DeferredTaggedToI(this, instr);
  
      // Branch to deferred code if the input is a HeapObject.
      __ JumpIfNotSmi(input_reg, deferred->entry());
  
      __ SmiUntag(input_reg);
      __ bind(deferred->exit());
    }
  }
  
  
  void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
    LOperand* input = instr->value();
    DCHECK(input->IsRegister());
    LOperand* result = instr->result();
    DCHECK(result->IsDoubleRegister());
  
    Register input_reg = ToRegister(input);
    DoubleRegister result_reg = ToDoubleRegister(result);
  
    HValue* value = instr->hydrogen()->value();
    NumberUntagDMode mode = value->representation().IsSmi()
                                ? NUMBER_CANDIDATE_IS_SMI
                                : NUMBER_CANDIDATE_IS_ANY_TAGGED;
  
    EmitNumberUntagD(instr, input_reg, result_reg, mode);
  }
  
  
  void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
    Register result_reg = ToRegister(instr->result());
    Register scratch1 = scratch0();
    DoubleRegister double_input = ToDoubleRegister(instr->value());
    DoubleRegister double_scratch = double_scratch0();
  
    if (instr->truncating()) {
      __ TruncateDoubleToI(result_reg, double_input);
    } else {
      __ TryDoubleToInt32Exact(result_reg, double_input, scratch1,
                               double_scratch);
      // Deoptimize if the input wasn't a int32 (inside a double).
      DeoptimizeIf(ne, instr, Deoptimizer::kLostPrecisionOrNaN);
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        Label done;
        __ cmpi(result_reg, Operand::Zero());
        __ bne(&done);
  #if V8_TARGET_ARCH_PPC64
        __ MovDoubleToInt64(scratch1, double_input);
  #else
        __ MovDoubleHighToInt(scratch1, double_input);
  #endif
        __ cmpi(scratch1, Operand::Zero());
        DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
        __ bind(&done);
      }
    }
  }
  
  
  void LCodeGen::DoDoubleToSmi(LDoubleToSmi* instr) {
    Register result_reg = ToRegister(instr->result());
    Register scratch1 = scratch0();
    DoubleRegister double_input = ToDoubleRegister(instr->value());
    DoubleRegister double_scratch = double_scratch0();
  
    if (instr->truncating()) {
      __ TruncateDoubleToI(result_reg, double_input);
    } else {
      __ TryDoubleToInt32Exact(result_reg, double_input, scratch1,
                               double_scratch);
      // Deoptimize if the input wasn't a int32 (inside a double).
      DeoptimizeIf(ne, instr, Deoptimizer::kLostPrecisionOrNaN);
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        Label done;
        __ cmpi(result_reg, Operand::Zero());
        __ bne(&done);
  #if V8_TARGET_ARCH_PPC64
        __ MovDoubleToInt64(scratch1, double_input);
  #else
        __ MovDoubleHighToInt(scratch1, double_input);
  #endif
        __ cmpi(scratch1, Operand::Zero());
        DeoptimizeIf(lt, instr, Deoptimizer::kMinusZero);
        __ bind(&done);
      }
    }
  #if V8_TARGET_ARCH_PPC64
    __ SmiTag(result_reg);
  #else
    __ SmiTagCheckOverflow(result_reg, r0);
    DeoptimizeIf(lt, instr, Deoptimizer::kOverflow, cr0);
  #endif
  }
  
  
  void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
    LOperand* input = instr->value();
    __ TestIfSmi(ToRegister(input), r0);
    DeoptimizeIf(ne, instr, Deoptimizer::kNotASmi, cr0);
  }
  
  
  void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
    if (!instr->hydrogen()->value()->type().IsHeapObject()) {
      LOperand* input = instr->value();
      __ TestIfSmi(ToRegister(input), r0);
      DeoptimizeIf(eq, instr, Deoptimizer::kSmi, cr0);
    }
  }
  
  
  void LCodeGen::DoCheckArrayBufferNotNeutered(
      LCheckArrayBufferNotNeutered* instr) {
    Register view = ToRegister(instr->view());
    Register scratch = scratch0();
  
    __ LoadP(scratch, FieldMemOperand(view, JSArrayBufferView::kBufferOffset));
    __ lwz(scratch, FieldMemOperand(scratch, JSArrayBuffer::kBitFieldOffset));
    __ andi(r0, scratch, Operand(1 << JSArrayBuffer::WasNeutered::kShift));
    DeoptimizeIf(ne, instr, Deoptimizer::kOutOfBounds, cr0);
  }
  
  
  void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
    Register input = ToRegister(instr->value());
    Register scratch = scratch0();
  
    __ LoadP(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
    __ lbz(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
  
    if (instr->hydrogen()->is_interval_check()) {
      InstanceType first;
      InstanceType last;
      instr->hydrogen()->GetCheckInterval(&first, &last);
  
      __ cmpli(scratch, Operand(first));
  
      // If there is only one type in the interval check for equality.
      if (first == last) {
        DeoptimizeIf(ne, instr, Deoptimizer::kWrongInstanceType);
      } else {
        DeoptimizeIf(lt, instr, Deoptimizer::kWrongInstanceType);
        // Omit check for the last type.
        if (last != LAST_TYPE) {
          __ cmpli(scratch, Operand(last));
          DeoptimizeIf(gt, instr, Deoptimizer::kWrongInstanceType);
        }
      }
    } else {
      uint8_t mask;
      uint8_t tag;
      instr->hydrogen()->GetCheckMaskAndTag(&mask, &tag);
  
      if (base::bits::IsPowerOfTwo32(mask)) {
        DCHECK(tag == 0 || base::bits::IsPowerOfTwo32(tag));
        __ andi(r0, scratch, Operand(mask));
        DeoptimizeIf(tag == 0 ? ne : eq, instr, Deoptimizer::kWrongInstanceType,
                     cr0);
      } else {
        __ andi(scratch, scratch, Operand(mask));
        __ cmpi(scratch, Operand(tag));
        DeoptimizeIf(ne, instr, Deoptimizer::kWrongInstanceType);
      }
    }
  }
  
  
  void LCodeGen::DoCheckValue(LCheckValue* instr) {
    Register reg = ToRegister(instr->value());
    Handle<HeapObject> object = instr->hydrogen()->object().handle();
    AllowDeferredHandleDereference smi_check;
    if (isolate()->heap()->InNewSpace(*object)) {
      Register reg = ToRegister(instr->value());
      Handle<Cell> cell = isolate()->factory()->NewCell(object);
      __ mov(ip, Operand(cell));
      __ LoadP(ip, FieldMemOperand(ip, Cell::kValueOffset));
      __ cmp(reg, ip);
    } else {
      __ Cmpi(reg, Operand(object), r0);
    }
    DeoptimizeIf(ne, instr, Deoptimizer::kValueMismatch);
  }
  
  
  void LCodeGen::DoDeferredInstanceMigration(LCheckMaps* instr, Register object) {
    Register temp = ToRegister(instr->temp());
    {
      PushSafepointRegistersScope scope(this);
      __ push(object);
      __ li(cp, Operand::Zero());
      __ CallRuntimeSaveDoubles(Runtime::kTryMigrateInstance);
      RecordSafepointWithRegisters(instr->pointer_map(), 1,
                                   Safepoint::kNoLazyDeopt);
      __ StoreToSafepointRegisterSlot(r3, temp);
    }
    __ TestIfSmi(temp, r0);
    DeoptimizeIf(eq, instr, Deoptimizer::kInstanceMigrationFailed, cr0);
  }
  
  
  void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
    class DeferredCheckMaps final : public LDeferredCode {
     public:
      DeferredCheckMaps(LCodeGen* codegen, LCheckMaps* instr, Register object)
          : LDeferredCode(codegen), instr_(instr), object_(object) {
        SetExit(check_maps());
      }
      void Generate() override {
        codegen()->DoDeferredInstanceMigration(instr_, object_);
      }
      Label* check_maps() { return &check_maps_; }
      LInstruction* instr() override { return instr_; }
  
     private:
      LCheckMaps* instr_;
      Label check_maps_;
      Register object_;
    };
  
    if (instr->hydrogen()->IsStabilityCheck()) {
      const UniqueSet<Map>* maps = instr->hydrogen()->maps();
      for (int i = 0; i < maps->size(); ++i) {
        AddStabilityDependency(maps->at(i).handle());
      }
      return;
    }
  
    Register object = ToRegister(instr->value());
    Register map_reg = ToRegister(instr->temp());
  
    __ LoadP(map_reg, FieldMemOperand(object, HeapObject::kMapOffset));
  
    DeferredCheckMaps* deferred = NULL;
    if (instr->hydrogen()->HasMigrationTarget()) {
      deferred = new (zone()) DeferredCheckMaps(this, instr, object);
      __ bind(deferred->check_maps());
    }
  
    const UniqueSet<Map>* maps = instr->hydrogen()->maps();
    Label success;
    for (int i = 0; i < maps->size() - 1; i++) {
      Handle<Map> map = maps->at(i).handle();
      __ CompareMap(map_reg, map, &success);
      __ beq(&success);
    }
  
    Handle<Map> map = maps->at(maps->size() - 1).handle();
    __ CompareMap(map_reg, map, &success);
    if (instr->hydrogen()->HasMigrationTarget()) {
      __ bne(deferred->entry());
    } else {
      DeoptimizeIf(ne, instr, Deoptimizer::kWrongMap);
    }
  
    __ bind(&success);
  }
  
  
  void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
    DoubleRegister value_reg = ToDoubleRegister(instr->unclamped());
    Register result_reg = ToRegister(instr->result());
    __ ClampDoubleToUint8(result_reg, value_reg, double_scratch0());
  }
  
  
  void LCodeGen::DoClampIToUint8(LClampIToUint8* instr) {
    Register unclamped_reg = ToRegister(instr->unclamped());
    Register result_reg = ToRegister(instr->result());
    __ ClampUint8(result_reg, unclamped_reg);
  }
  
  
  void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
    Register scratch = scratch0();
    Register input_reg = ToRegister(instr->unclamped());
    Register result_reg = ToRegister(instr->result());
    DoubleRegister temp_reg = ToDoubleRegister(instr->temp());
    Label is_smi, done, heap_number;
  
    // Both smi and heap number cases are handled.
    __ UntagAndJumpIfSmi(result_reg, input_reg, &is_smi);
  
    // Check for heap number
    __ LoadP(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
    __ Cmpi(scratch, Operand(factory()->heap_number_map()), r0);
    __ beq(&heap_number);
  
    // Check for undefined. Undefined is converted to zero for clamping
    // conversions.
    __ Cmpi(input_reg, Operand(factory()->undefined_value()), r0);
    DeoptimizeIf(ne, instr, Deoptimizer::kNotAHeapNumberUndefined);
    __ li(result_reg, Operand::Zero());
    __ b(&done);
  
    // Heap number
    __ bind(&heap_number);
    __ lfd(temp_reg, FieldMemOperand(input_reg, HeapNumber::kValueOffset));
    __ ClampDoubleToUint8(result_reg, temp_reg, double_scratch0());
    __ b(&done);
  
    // smi
    __ bind(&is_smi);
    __ ClampUint8(result_reg, result_reg);
  
    __ bind(&done);
  }
  
  
  void LCodeGen::DoDoubleBits(LDoubleBits* instr) {
    DoubleRegister value_reg = ToDoubleRegister(instr->value());
    Register result_reg = ToRegister(instr->result());
  
    if (instr->hydrogen()->bits() == HDoubleBits::HIGH) {
      __ MovDoubleHighToInt(result_reg, value_reg);
    } else {
      __ MovDoubleLowToInt(result_reg, value_reg);
    }
  }
  
  
  void LCodeGen::DoConstructDouble(LConstructDouble* instr) {
    Register hi_reg = ToRegister(instr->hi());
    Register lo_reg = ToRegister(instr->lo());
    DoubleRegister result_reg = ToDoubleRegister(instr->result());
  #if V8_TARGET_ARCH_PPC64
    __ MovInt64ComponentsToDouble(result_reg, hi_reg, lo_reg, r0);
  #else
    __ MovInt64ToDouble(result_reg, hi_reg, lo_reg);
  #endif
  }
  
  
  void LCodeGen::DoAllocate(LAllocate* instr) {
    class DeferredAllocate final : public LDeferredCode {
     public:
      DeferredAllocate(LCodeGen* codegen, LAllocate* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override { codegen()->DoDeferredAllocate(instr_); }
      LInstruction* instr() override { return instr_; }
  
     private:
      LAllocate* instr_;
    };
  
    DeferredAllocate* deferred = new (zone()) DeferredAllocate(this, instr);
  
    Register result = ToRegister(instr->result());
    Register scratch = ToRegister(instr->temp1());
    Register scratch2 = ToRegister(instr->temp2());
  
    // Allocate memory for the object.
    AllocationFlags flags = TAG_OBJECT;
    if (instr->hydrogen()->MustAllocateDoubleAligned()) {
      flags = static_cast<AllocationFlags>(flags | DOUBLE_ALIGNMENT);
    }
    if (instr->hydrogen()->IsOldSpaceAllocation()) {
      DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
      flags = static_cast<AllocationFlags>(flags | PRETENURE);
    }
  
    if (instr->size()->IsConstantOperand()) {
      int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
      CHECK(size <= Page::kMaxRegularHeapObjectSize);
      __ Allocate(size, result, scratch, scratch2, deferred->entry(), flags);
    } else {
      Register size = ToRegister(instr->size());
      __ Allocate(size, result, scratch, scratch2, deferred->entry(), flags);
    }
  
    __ bind(deferred->exit());
  
    if (instr->hydrogen()->MustPrefillWithFiller()) {
      if (instr->size()->IsConstantOperand()) {
        int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
        __ LoadIntLiteral(scratch, size - kHeapObjectTag);
      } else {
        __ subi(scratch, ToRegister(instr->size()), Operand(kHeapObjectTag));
      }
      __ mov(scratch2, Operand(isolate()->factory()->one_pointer_filler_map()));
      Label loop;
      __ bind(&loop);
      __ subi(scratch, scratch, Operand(kPointerSize));
      __ StorePX(scratch2, MemOperand(result, scratch));
      __ cmpi(scratch, Operand::Zero());
      __ bge(&loop);
    }
  }
  
  
  void LCodeGen::DoDeferredAllocate(LAllocate* instr) {
    Register result = ToRegister(instr->result());
  
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    __ LoadSmiLiteral(result, Smi::FromInt(0));
  
    PushSafepointRegistersScope scope(this);
    if (instr->size()->IsRegister()) {
      Register size = ToRegister(instr->size());
      DCHECK(!size.is(result));
      __ SmiTag(size);
      __ push(size);
    } else {
      int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
  #if !V8_TARGET_ARCH_PPC64
      if (size >= 0 && size <= Smi::kMaxValue) {
  #endif
        __ Push(Smi::FromInt(size));
  #if !V8_TARGET_ARCH_PPC64
      } else {
        // We should never get here at runtime => abort
        __ stop("invalid allocation size");
        return;
      }
  #endif
    }
  
    int flags = AllocateDoubleAlignFlag::encode(
        instr->hydrogen()->MustAllocateDoubleAligned());
    if (instr->hydrogen()->IsOldSpaceAllocation()) {
      DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
      flags = AllocateTargetSpace::update(flags, OLD_SPACE);
    } else {
      flags = AllocateTargetSpace::update(flags, NEW_SPACE);
    }
    __ Push(Smi::FromInt(flags));
  
    CallRuntimeFromDeferred(Runtime::kAllocateInTargetSpace, 2, instr,
                            instr->context());
    __ StoreToSafepointRegisterSlot(r3, result);
  }
  
  
  void LCodeGen::DoToFastProperties(LToFastProperties* instr) {
    DCHECK(ToRegister(instr->value()).is(r3));
    __ push(r3);
    CallRuntime(Runtime::kToFastProperties, 1, instr);
  }
  
  
  void LCodeGen::DoTypeof(LTypeof* instr) {
    DCHECK(ToRegister(instr->value()).is(r6));
    DCHECK(ToRegister(instr->result()).is(r3));
    Label end, do_call;
    Register value_register = ToRegister(instr->value());
    __ JumpIfNotSmi(value_register, &do_call);
    __ mov(r3, Operand(isolate()->factory()->number_string()));
    __ b(&end);
    __ bind(&do_call);
    TypeofStub stub(isolate());
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    __ bind(&end);
  }
  
  
  void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
    Register input = ToRegister(instr->value());
  
    Condition final_branch_condition =
        EmitTypeofIs(instr->TrueLabel(chunk_), instr->FalseLabel(chunk_), input,
                     instr->type_literal());
    if (final_branch_condition != kNoCondition) {
      EmitBranch(instr, final_branch_condition);
    }
  }
  
  
  Condition LCodeGen::EmitTypeofIs(Label* true_label, Label* false_label,
                                   Register input, Handle<String> type_name) {
    Condition final_branch_condition = kNoCondition;
    Register scratch = scratch0();
    Factory* factory = isolate()->factory();
    if (String::Equals(type_name, factory->number_string())) {
      __ JumpIfSmi(input, true_label);
      __ LoadP(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
      __ CompareRoot(scratch, Heap::kHeapNumberMapRootIndex);
      final_branch_condition = eq;
  
    } else if (String::Equals(type_name, factory->string_string())) {
      __ JumpIfSmi(input, false_label);
      __ CompareObjectType(input, scratch, no_reg, FIRST_NONSTRING_TYPE);
      final_branch_condition = lt;
  
    } else if (String::Equals(type_name, factory->symbol_string())) {
      __ JumpIfSmi(input, false_label);
      __ CompareObjectType(input, scratch, no_reg, SYMBOL_TYPE);
      final_branch_condition = eq;
  
    } else if (String::Equals(type_name, factory->boolean_string())) {
      __ CompareRoot(input, Heap::kTrueValueRootIndex);
      __ beq(true_label);
      __ CompareRoot(input, Heap::kFalseValueRootIndex);
      final_branch_condition = eq;
  
    } else if (String::Equals(type_name, factory->undefined_string())) {
      __ CompareRoot(input, Heap::kUndefinedValueRootIndex);
      __ beq(true_label);
      __ JumpIfSmi(input, false_label);
      // Check for undetectable objects => true.
      __ LoadP(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
      __ lbz(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
      __ ExtractBit(r0, scratch, Map::kIsUndetectable);
      __ cmpi(r0, Operand::Zero());
      final_branch_condition = ne;
  
    } else if (String::Equals(type_name, factory->function_string())) {
      __ JumpIfSmi(input, false_label);
      __ LoadP(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
      __ lbz(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
      __ andi(scratch, scratch,
              Operand((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
      __ cmpi(scratch, Operand(1 << Map::kIsCallable));
      final_branch_condition = eq;
  
    } else if (String::Equals(type_name, factory->object_string())) {
      __ JumpIfSmi(input, false_label);
      __ CompareRoot(input, Heap::kNullValueRootIndex);
      __ beq(true_label);
      STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
      __ CompareObjectType(input, scratch, ip, FIRST_JS_RECEIVER_TYPE);
      __ blt(false_label);
      // Check for callable or undetectable objects => false.
      __ lbz(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
      __ andi(r0, scratch,
              Operand((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
      __ cmpi(r0, Operand::Zero());
      final_branch_condition = eq;
  
  // clang-format off
  #define SIMD128_TYPE(TYPE, Type, type, lane_count, lane_type)        \
    } else if (String::Equals(type_name, factory->type##_string())) {  \
      __ JumpIfSmi(input, false_label);                                \
      __ LoadP(scratch, FieldMemOperand(input, HeapObject::kMapOffset)); \
      __ CompareRoot(scratch, Heap::k##Type##MapRootIndex);            \
      final_branch_condition = eq;
    SIMD128_TYPES(SIMD128_TYPE)
  #undef SIMD128_TYPE
      // clang-format on
  
    } else {
      __ b(false_label);
    }
  
    return final_branch_condition;
  }
  
  
  void LCodeGen::EnsureSpaceForLazyDeopt(int space_needed) {
    if (info()->ShouldEnsureSpaceForLazyDeopt()) {
      // Ensure that we have enough space after the previous lazy-bailout
      // instruction for patching the code here.
      int current_pc = masm()->pc_offset();
      if (current_pc < last_lazy_deopt_pc_ + space_needed) {
        int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
        DCHECK_EQ(0, padding_size % Assembler::kInstrSize);
        while (padding_size > 0) {
          __ nop();
          padding_size -= Assembler::kInstrSize;
        }
      }
    }
    last_lazy_deopt_pc_ = masm()->pc_offset();
  }
  
  
  void LCodeGen::DoLazyBailout(LLazyBailout* instr) {
    last_lazy_deopt_pc_ = masm()->pc_offset();
    DCHECK(instr->HasEnvironment());
    LEnvironment* env = instr->environment();
    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
  }
  
  
  void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
    Deoptimizer::BailoutType type = instr->hydrogen()->type();
    // TODO(danno): Stubs expect all deopts to be lazy for historical reasons (the
    // needed return address), even though the implementation of LAZY and EAGER is
    // now identical. When LAZY is eventually completely folded into EAGER, remove
    // the special case below.
    if (info()->IsStub() && type == Deoptimizer::EAGER) {
      type = Deoptimizer::LAZY;
    }
  
    DeoptimizeIf(al, instr, instr->hydrogen()->reason(), type);
  }
  
  
  void LCodeGen::DoDummy(LDummy* instr) {
    // Nothing to see here, move on!
  }
  
  
  void LCodeGen::DoDummyUse(LDummyUse* instr) {
    // Nothing to see here, move on!
  }
  
  
  void LCodeGen::DoDeferredStackCheck(LStackCheck* instr) {
    PushSafepointRegistersScope scope(this);
    LoadContextFromDeferred(instr->context());
    __ CallRuntimeSaveDoubles(Runtime::kStackGuard);
    RecordSafepointWithLazyDeopt(
        instr, RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
    DCHECK(instr->HasEnvironment());
    LEnvironment* env = instr->environment();
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
  }
  
  
  void LCodeGen::DoStackCheck(LStackCheck* instr) {
    class DeferredStackCheck final : public LDeferredCode {
     public:
      DeferredStackCheck(LCodeGen* codegen, LStackCheck* instr)
          : LDeferredCode(codegen), instr_(instr) {}
      void Generate() override { codegen()->DoDeferredStackCheck(instr_); }
      LInstruction* instr() override { return instr_; }
  
     private:
      LStackCheck* instr_;
    };
  
    DCHECK(instr->HasEnvironment());
    LEnvironment* env = instr->environment();
    // There is no LLazyBailout instruction for stack-checks. We have to
    // prepare for lazy deoptimization explicitly here.
    if (instr->hydrogen()->is_function_entry()) {
      // Perform stack overflow check.
      Label done;
      __ LoadRoot(ip, Heap::kStackLimitRootIndex);
      __ cmpl(sp, ip);
      __ bge(&done);
      DCHECK(instr->context()->IsRegister());
      DCHECK(ToRegister(instr->context()).is(cp));
      CallCode(isolate()->builtins()->StackCheck(), RelocInfo::CODE_TARGET,
               instr);
      __ bind(&done);
    } else {
      DCHECK(instr->hydrogen()->is_backwards_branch());
      // Perform stack overflow check if this goto needs it before jumping.
      DeferredStackCheck* deferred_stack_check =
          new (zone()) DeferredStackCheck(this, instr);
      __ LoadRoot(ip, Heap::kStackLimitRootIndex);
      __ cmpl(sp, ip);
      __ blt(deferred_stack_check->entry());
      EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
      __ bind(instr->done_label());
      deferred_stack_check->SetExit(instr->done_label());
      RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
      // Don't record a deoptimization index for the safepoint here.
      // This will be done explicitly when emitting call and the safepoint in
      // the deferred code.
    }
  }
  
  
  void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
    // This is a pseudo-instruction that ensures that the environment here is
    // properly registered for deoptimization and records the assembler's PC
    // offset.
    LEnvironment* environment = instr->environment();
  
    // If the environment were already registered, we would have no way of
    // backpatching it with the spill slot operands.
    DCHECK(!environment->HasBeenRegistered());
    RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
  
    GenerateOsrPrologue();
  }
  
  
  void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
    __ TestIfSmi(r3, r0);
    DeoptimizeIf(eq, instr, Deoptimizer::kSmi, cr0);
  
    STATIC_ASSERT(JS_PROXY_TYPE == FIRST_JS_RECEIVER_TYPE);
    __ CompareObjectType(r3, r4, r4, JS_PROXY_TYPE);
    DeoptimizeIf(le, instr, Deoptimizer::kWrongInstanceType);
  
    Label use_cache, call_runtime;
    Register null_value = r8;
    __ LoadRoot(null_value, Heap::kNullValueRootIndex);
    __ CheckEnumCache(null_value, &call_runtime);
  
    __ LoadP(r3, FieldMemOperand(r3, HeapObject::kMapOffset));
    __ b(&use_cache);
  
    // Get the set of properties to enumerate.
    __ bind(&call_runtime);
    __ push(r3);
    CallRuntime(Runtime::kGetPropertyNamesFast, instr);
  
    __ LoadP(r4, FieldMemOperand(r3, HeapObject::kMapOffset));
    __ LoadRoot(ip, Heap::kMetaMapRootIndex);
    __ cmp(r4, ip);
    DeoptimizeIf(ne, instr, Deoptimizer::kWrongMap);
    __ bind(&use_cache);
  }
  
  
  void LCodeGen::DoForInCacheArray(LForInCacheArray* instr) {
    Register map = ToRegister(instr->map());
    Register result = ToRegister(instr->result());
    Label load_cache, done;
    __ EnumLength(result, map);
    __ CmpSmiLiteral(result, Smi::FromInt(0), r0);
    __ bne(&load_cache);
    __ mov(result, Operand(isolate()->factory()->empty_fixed_array()));
    __ b(&done);
  
    __ bind(&load_cache);
    __ LoadInstanceDescriptors(map, result);
    __ LoadP(result, FieldMemOperand(result, DescriptorArray::kEnumCacheOffset));
    __ LoadP(result, FieldMemOperand(result, FixedArray::SizeFor(instr->idx())));
    __ cmpi(result, Operand::Zero());
    DeoptimizeIf(eq, instr, Deoptimizer::kNoCache);
  
    __ bind(&done);
  }
  
  
  void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
    Register object = ToRegister(instr->value());
    Register map = ToRegister(instr->map());
    __ LoadP(scratch0(), FieldMemOperand(object, HeapObject::kMapOffset));
    __ cmp(map, scratch0());
    DeoptimizeIf(ne, instr, Deoptimizer::kWrongMap);
  }
  
  
  void LCodeGen::DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
                                             Register result, Register object,
                                             Register index) {
    PushSafepointRegistersScope scope(this);
    __ Push(object, index);
    __ li(cp, Operand::Zero());
    __ CallRuntimeSaveDoubles(Runtime::kLoadMutableDouble);
    RecordSafepointWithRegisters(instr->pointer_map(), 2,
                                 Safepoint::kNoLazyDeopt);
    __ StoreToSafepointRegisterSlot(r3, result);
  }
  
  
  void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
    class DeferredLoadMutableDouble final : public LDeferredCode {
     public:
      DeferredLoadMutableDouble(LCodeGen* codegen, LLoadFieldByIndex* instr,
                                Register result, Register object, Register index)
          : LDeferredCode(codegen),
            instr_(instr),
            result_(result),
            object_(object),
            index_(index) {}
      void Generate() override {
        codegen()->DoDeferredLoadMutableDouble(instr_, result_, object_, index_);
      }
      LInstruction* instr() override { return instr_; }
  
     private:
      LLoadFieldByIndex* instr_;
      Register result_;
      Register object_;
      Register index_;
    };
  
    Register object = ToRegister(instr->object());
    Register index = ToRegister(instr->index());
    Register result = ToRegister(instr->result());
    Register scratch = scratch0();
  
    DeferredLoadMutableDouble* deferred;
    deferred = new (zone())
        DeferredLoadMutableDouble(this, instr, result, object, index);
  
    Label out_of_object, done;
  
    __ TestBitMask(index, reinterpret_cast<uintptr_t>(Smi::FromInt(1)), r0);
    __ bne(deferred->entry(), cr0);
    __ ShiftRightArithImm(index, index, 1);
  
    __ cmpi(index, Operand::Zero());
    __ blt(&out_of_object);
  
    __ SmiToPtrArrayOffset(r0, index);
    __ add(scratch, object, r0);
    __ LoadP(result, FieldMemOperand(scratch, JSObject::kHeaderSize));
  
    __ b(&done);
  
    __ bind(&out_of_object);
    __ LoadP(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
    // Index is equal to negated out of object property index plus 1.
    __ SmiToPtrArrayOffset(r0, index);
    __ sub(scratch, result, r0);
    __ LoadP(result,
             FieldMemOperand(scratch, FixedArray::kHeaderSize - kPointerSize));
    __ bind(deferred->exit());
    __ bind(&done);
  }
  
  
  void LCodeGen::DoStoreFrameContext(LStoreFrameContext* instr) {
    Register context = ToRegister(instr->context());
    __ StoreP(context, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoAllocateBlockContext(LAllocateBlockContext* instr) {
    Handle<ScopeInfo> scope_info = instr->scope_info();
    __ Push(scope_info);
    __ push(ToRegister(instr->function()));
    CallRuntime(Runtime::kPushBlockContext, instr);
    RecordSafepoint(Safepoint::kNoLazyDeopt);
  }
  
  
  #undef __
  }  // namespace internal
  }  // namespace v8
  