compiler/optimizing/code_generator_arm.cc

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "code_generator_arm.h"

#include "entrypoints/quick/quick_entrypoints.h"
#include "gc/accounting/card_table.h"
#include "mirror/array-inl.h"
#include "mirror/art_method.h"
#include "mirror/class.h"
#include "thread.h"
#include "utils/assembler.h"
#include "utils/arm/assembler_arm.h"
#include "utils/arm/managed_register_arm.h"
#include "utils/stack_checks.h"

namespace art {

namespace arm {

static SRegister FromDToLowS(DRegister reg) {
  return static_cast<SRegister>(reg * 2);
}

static constexpr bool kExplicitStackOverflowCheck = false;

static constexpr int kNumberOfPushedRegistersAtEntry = 1 + 2;  // LR, R6, R7
static constexpr int kCurrentMethodStackOffset = 0;

static constexpr Register kRuntimeParameterCoreRegisters[] = { R0, R1, R2 };
static constexpr size_t kRuntimeParameterCoreRegistersLength =
    arraysize(kRuntimeParameterCoreRegisters);
static constexpr DRegister kRuntimeParameterFpuRegisters[] = { };
static constexpr size_t kRuntimeParameterFpuRegistersLength = 0;

class InvokeRuntimeCallingConvention : public CallingConvention<Register, DRegister> {
 public:
  InvokeRuntimeCallingConvention()
      : CallingConvention(kRuntimeParameterCoreRegisters,
                          kRuntimeParameterCoreRegistersLength,
                          kRuntimeParameterFpuRegisters,
                          kRuntimeParameterFpuRegistersLength) {}

 private:
  DISALLOW_COPY_AND_ASSIGN(InvokeRuntimeCallingConvention);
};

#define __ reinterpret_cast<ArmAssembler*>(codegen->GetAssembler())->

class SlowPathCodeARM : public SlowPathCode {
 public:
  SlowPathCodeARM() : entry_label_(), exit_label_() {}

  Label* GetEntryLabel() { return &entry_label_; }
  Label* GetExitLabel() { return &exit_label_; }

 private:
  Label entry_label_;
  Label exit_label_;

  DISALLOW_COPY_AND_ASSIGN(SlowPathCodeARM);
};

class NullCheckSlowPathARM : public SlowPathCodeARM {
 public:
  explicit NullCheckSlowPathARM(HNullCheck* instruction) : instruction_(instruction) {}

  virtual void EmitNativeCode(CodeGenerator* codegen) OVERRIDE {
    __ Bind(GetEntryLabel());
    int32_t offset = QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pThrowNullPointer).Int32Value();
    __ LoadFromOffset(kLoadWord, LR, TR, offset);
    __ blx(LR);
    codegen->RecordPcInfo(instruction_, instruction_->GetDexPc());
  }

 private:
  HNullCheck* const instruction_;
  DISALLOW_COPY_AND_ASSIGN(NullCheckSlowPathARM);
};

class StackOverflowCheckSlowPathARM : public SlowPathCodeARM {
 public:
  StackOverflowCheckSlowPathARM() {}

  virtual void EmitNativeCode(CodeGenerator* codegen) OVERRIDE {
    __ Bind(GetEntryLabel());
    __ LoadFromOffset(kLoadWord, PC, TR,
        QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pThrowStackOverflow).Int32Value());
  }

 private:
  DISALLOW_COPY_AND_ASSIGN(StackOverflowCheckSlowPathARM);
};

class SuspendCheckSlowPathARM : public SlowPathCodeARM {
 public:
  explicit SuspendCheckSlowPathARM(HSuspendCheck* instruction, HBasicBlock* successor)
      : instruction_(instruction), successor_(successor) {}

  virtual void EmitNativeCode(CodeGenerator* codegen) OVERRIDE {
    CodeGeneratorARM* arm_codegen = down_cast<CodeGeneratorARM*>(codegen);
    __ Bind(GetEntryLabel());
    codegen->SaveLiveRegisters(instruction_->GetLocations());
    int32_t offset = QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pTestSuspend).Int32Value();
    __ LoadFromOffset(kLoadWord, LR, TR, offset);
    __ blx(LR);
    codegen->RecordPcInfo(instruction_, instruction_->GetDexPc());
    codegen->RestoreLiveRegisters(instruction_->GetLocations());
    if (successor_ == nullptr) {
      __ b(GetReturnLabel());
    } else {
      __ b(arm_codegen->GetLabelOf(successor_));
    }
  }

  Label* GetReturnLabel() {
    DCHECK(successor_ == nullptr);
    return &return_label_;
  }

 private:
  HSuspendCheck* const instruction_;
  // If not null, the block to branch to after the suspend check.
  HBasicBlock* const successor_;

  // If `successor_` is null, the label to branch to after the suspend check.
  Label return_label_;

  DISALLOW_COPY_AND_ASSIGN(SuspendCheckSlowPathARM);
};

class BoundsCheckSlowPathARM : public SlowPathCodeARM {
 public:
  BoundsCheckSlowPathARM(HBoundsCheck* instruction,
                         Location index_location,
                         Location length_location)
      : instruction_(instruction),
        index_location_(index_location),
        length_location_(length_location) {}

  virtual void EmitNativeCode(CodeGenerator* codegen) OVERRIDE {
    CodeGeneratorARM* arm_codegen = down_cast<CodeGeneratorARM*>(codegen);
    __ Bind(GetEntryLabel());
    InvokeRuntimeCallingConvention calling_convention;
    arm_codegen->Move32(Location::RegisterLocation(calling_convention.GetRegisterAt(0)), index_location_);
    arm_codegen->Move32(Location::RegisterLocation(calling_convention.GetRegisterAt(1)), length_location_);
    int32_t offset = QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pThrowArrayBounds).Int32Value();
    __ LoadFromOffset(kLoadWord, LR, TR, offset);
    __ blx(LR);
    codegen->RecordPcInfo(instruction_, instruction_->GetDexPc());
  }

 private:
  HBoundsCheck* const instruction_;
  const Location index_location_;
  const Location length_location_;

  DISALLOW_COPY_AND_ASSIGN(BoundsCheckSlowPathARM);
};

#undef __
#define __ reinterpret_cast<ArmAssembler*>(GetAssembler())->

inline Condition ARMCondition(IfCondition cond) {
  switch (cond) {
    case kCondEQ: return EQ;
    case kCondNE: return NE;
    case kCondLT: return LT;
    case kCondLE: return LE;
    case kCondGT: return GT;
    case kCondGE: return GE;
    default:
      LOG(FATAL) << "Unknown if condition";
  }
  return EQ;        // Unreachable.
}

inline Condition ARMOppositeCondition(IfCondition cond) {
  switch (cond) {
    case kCondEQ: return NE;
    case kCondNE: return EQ;
    case kCondLT: return GE;
    case kCondLE: return GT;
    case kCondGT: return LE;
    case kCondGE: return LT;
    default:
      LOG(FATAL) << "Unknown if condition";
  }
  return EQ;        // Unreachable.
}

void CodeGeneratorARM::DumpCoreRegister(std::ostream& stream, int reg) const {
  stream << ArmManagedRegister::FromCoreRegister(Register(reg));
}

void CodeGeneratorARM::DumpFloatingPointRegister(std::ostream& stream, int reg) const {
  stream << ArmManagedRegister::FromDRegister(DRegister(reg));
}

void CodeGeneratorARM::SaveCoreRegister(Location stack_location, uint32_t reg_id) {
  __ StoreToOffset(kStoreWord, static_cast<Register>(reg_id), SP, stack_location.GetStackIndex());
}

void CodeGeneratorARM::RestoreCoreRegister(Location stack_location, uint32_t reg_id) {
  __ LoadFromOffset(kLoadWord, static_cast<Register>(reg_id), SP, stack_location.GetStackIndex());
}

CodeGeneratorARM::CodeGeneratorARM(HGraph* graph)
    : CodeGenerator(graph, kNumberOfCoreRegisters, kNumberOfDRegisters, kNumberOfRegisterPairs),
      block_labels_(graph->GetArena(), 0),
      location_builder_(graph, this),
      instruction_visitor_(graph, this),
      move_resolver_(graph->GetArena(), this),
      assembler_(true) {}

size_t CodeGeneratorARM::FrameEntrySpillSize() const {
  return kNumberOfPushedRegistersAtEntry * kArmWordSize;
}

Location CodeGeneratorARM::AllocateFreeRegister(Primitive::Type type) const {
  switch (type) {
    case Primitive::kPrimLong: {
      size_t reg = FindFreeEntry(blocked_register_pairs_, kNumberOfRegisterPairs);
      ArmManagedRegister pair =
          ArmManagedRegister::FromRegisterPair(static_cast<RegisterPair>(reg));
      DCHECK(!blocked_core_registers_[pair.AsRegisterPairLow()]);
      DCHECK(!blocked_core_registers_[pair.AsRegisterPairHigh()]);

      blocked_core_registers_[pair.AsRegisterPairLow()] = true;
      blocked_core_registers_[pair.AsRegisterPairHigh()] = true;
      UpdateBlockedPairRegisters();
      return Location::RegisterPairLocation(pair.AsRegisterPairLow(), pair.AsRegisterPairHigh());
    }

    case Primitive::kPrimByte:
    case Primitive::kPrimBoolean:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
    case Primitive::kPrimInt:
    case Primitive::kPrimNot: {
      int reg = FindFreeEntry(blocked_core_registers_, kNumberOfCoreRegisters);
      // Block all register pairs that contain `reg`.
      for (int i = 0; i < kNumberOfRegisterPairs; i++) {
        ArmManagedRegister current =
            ArmManagedRegister::FromRegisterPair(static_cast<RegisterPair>(i));
        if (current.AsRegisterPairLow() == reg || current.AsRegisterPairHigh() == reg) {
          blocked_register_pairs_[i] = true;
        }
      }
      return Location::RegisterLocation(reg);
    }

    case Primitive::kPrimFloat:
    case Primitive::kPrimDouble: {
      int reg = FindFreeEntry(blocked_fpu_registers_, kNumberOfDRegisters);
      return Location::FpuRegisterLocation(reg);
    }

    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unreachable type " << type;
  }

  return Location();
}

void CodeGeneratorARM::SetupBlockedRegisters() const {
  // Don't allocate the dalvik style register pair passing.
  blocked_register_pairs_[R1_R2] = true;

  // Stack register, LR and PC are always reserved.
  blocked_core_registers_[SP] = true;
  blocked_core_registers_[LR] = true;
  blocked_core_registers_[PC] = true;

  // Reserve R4 for suspend check.
  blocked_core_registers_[R4] = true;

  // Reserve thread register.
  blocked_core_registers_[TR] = true;

  // Reserve temp register.
  blocked_core_registers_[IP] = true;

  // TODO: We currently don't use Quick's callee saved registers.
  // We always save and restore R6 and R7 to make sure we can use three
  // register pairs for long operations.
  blocked_core_registers_[R5] = true;
  blocked_core_registers_[R8] = true;
  blocked_core_registers_[R10] = true;
  blocked_core_registers_[R11] = true;

  blocked_fpu_registers_[D8] = true;
  blocked_fpu_registers_[D9] = true;
  blocked_fpu_registers_[D10] = true;
  blocked_fpu_registers_[D11] = true;
  blocked_fpu_registers_[D12] = true;
  blocked_fpu_registers_[D13] = true;
  blocked_fpu_registers_[D14] = true;
  blocked_fpu_registers_[D15] = true;

  UpdateBlockedPairRegisters();
}

void CodeGeneratorARM::UpdateBlockedPairRegisters() const {
  for (int i = 0; i < kNumberOfRegisterPairs; i++) {
    ArmManagedRegister current =
        ArmManagedRegister::FromRegisterPair(static_cast<RegisterPair>(i));
    if (blocked_core_registers_[current.AsRegisterPairLow()]
        || blocked_core_registers_[current.AsRegisterPairHigh()]) {
      blocked_register_pairs_[i] = true;
    }
  }
}

InstructionCodeGeneratorARM::InstructionCodeGeneratorARM(HGraph* graph, CodeGeneratorARM* codegen)
      : HGraphVisitor(graph),
        assembler_(codegen->GetAssembler()),
        codegen_(codegen) {}

void CodeGeneratorARM::GenerateFrameEntry() {
  bool skip_overflow_check = IsLeafMethod() && !FrameNeedsStackCheck(GetFrameSize(), InstructionSet::kArm);
  if (!skip_overflow_check) {
    if (kExplicitStackOverflowCheck) {
      SlowPathCodeARM* slow_path = new (GetGraph()->GetArena()) StackOverflowCheckSlowPathARM();
      AddSlowPath(slow_path);

      __ LoadFromOffset(kLoadWord, IP, TR, Thread::StackEndOffset<kArmWordSize>().Int32Value());
      __ cmp(SP, ShifterOperand(IP));
      __ b(slow_path->GetEntryLabel(), CC);
    } else {
      __ AddConstant(IP, SP, -static_cast<int32_t>(GetStackOverflowReservedBytes(kArm)));
      __ LoadFromOffset(kLoadWord, IP, IP, 0);
      RecordPcInfo(nullptr, 0);
    }
  }

  core_spill_mask_ |= (1 << LR | 1 << R6 | 1 << R7);
  __ PushList(1 << LR | 1 << R6 | 1 << R7);

  // The return PC has already been pushed on the stack.
  __ AddConstant(SP, -(GetFrameSize() - kNumberOfPushedRegistersAtEntry * kArmWordSize));
  __ StoreToOffset(kStoreWord, R0, SP, 0);
}

void CodeGeneratorARM::GenerateFrameExit() {
  __ AddConstant(SP, GetFrameSize() - kNumberOfPushedRegistersAtEntry * kArmWordSize);
  __ PopList(1 << PC | 1 << R6 | 1 << R7);
}

void CodeGeneratorARM::Bind(HBasicBlock* block) {
  __ Bind(GetLabelOf(block));
}

Location CodeGeneratorARM::GetStackLocation(HLoadLocal* load) const {
  switch (load->GetType()) {
    case Primitive::kPrimLong:
    case Primitive::kPrimDouble:
      return Location::DoubleStackSlot(GetStackSlot(load->GetLocal()));
      break;

    case Primitive::kPrimInt:
    case Primitive::kPrimNot:
    case Primitive::kPrimFloat:
      return Location::StackSlot(GetStackSlot(load->GetLocal()));

    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unexpected type " << load->GetType();
  }

  LOG(FATAL) << "Unreachable";
  return Location();
}

Location InvokeDexCallingConventionVisitor::GetNextLocation(Primitive::Type type) {
  switch (type) {
    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
    case Primitive::kPrimInt:
    case Primitive::kPrimFloat:
    case Primitive::kPrimNot: {
      uint32_t index = gp_index_++;
      if (index < calling_convention.GetNumberOfRegisters()) {
        return Location::RegisterLocation(calling_convention.GetRegisterAt(index));
      } else {
        return Location::StackSlot(calling_convention.GetStackOffsetOf(index));
      }
    }

    case Primitive::kPrimLong:
    case Primitive::kPrimDouble: {
      uint32_t index = gp_index_;
      gp_index_ += 2;
      if (index + 1 < calling_convention.GetNumberOfRegisters()) {
        ArmManagedRegister pair = ArmManagedRegister::FromRegisterPair(
            calling_convention.GetRegisterPairAt(index));
        return Location::RegisterPairLocation(pair.AsRegisterPairLow(), pair.AsRegisterPairHigh());
      } else if (index + 1 == calling_convention.GetNumberOfRegisters()) {
        return Location::QuickParameter(index);
      } else {
        return Location::DoubleStackSlot(calling_convention.GetStackOffsetOf(index));
      }
    }

    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unexpected parameter type " << type;
      break;
  }
  return Location();
}

void CodeGeneratorARM::Move32(Location destination, Location source) {
  if (source.Equals(destination)) {
    return;
  }
  if (destination.IsRegister()) {
    if (source.IsRegister()) {
      __ Mov(destination.As<Register>(), source.As<Register>());
    } else if (source.IsFpuRegister()) {
      __ vmovrs(destination.As<Register>(), FromDToLowS(source.As<DRegister>()));
    } else {
      __ LoadFromOffset(kLoadWord, destination.As<Register>(), SP, source.GetStackIndex());
    }
  } else if (destination.IsFpuRegister()) {
    if (source.IsRegister()) {
      __ vmovsr(FromDToLowS(destination.As<DRegister>()), source.As<Register>());
    } else if (source.IsFpuRegister()) {
      __ vmovs(FromDToLowS(destination.As<DRegister>()), FromDToLowS(source.As<DRegister>()));
    } else {
      __ vldrs(FromDToLowS(destination.As<DRegister>()), Address(SP, source.GetStackIndex()));
    }
  } else {
    DCHECK(destination.IsStackSlot());
    if (source.IsRegister()) {
      __ StoreToOffset(kStoreWord, source.As<Register>(), SP, destination.GetStackIndex());
    } else if (source.IsFpuRegister()) {
      __ vstrs(FromDToLowS(source.As<DRegister>()), Address(SP, destination.GetStackIndex()));
    } else {
      DCHECK(source.IsStackSlot());
      __ LoadFromOffset(kLoadWord, IP, SP, source.GetStackIndex());
      __ StoreToOffset(kStoreWord, IP, SP, destination.GetStackIndex());
    }
  }
}

void CodeGeneratorARM::Move64(Location destination, Location source) {
  if (source.Equals(destination)) {
    return;
  }
  if (destination.IsRegisterPair()) {
    if (source.IsRegisterPair()) {
      __ Mov(destination.AsRegisterPairLow<Register>(), source.AsRegisterPairLow<Register>());
      __ Mov(destination.AsRegisterPairHigh<Register>(), source.AsRegisterPairHigh<Register>());
    } else if (source.IsFpuRegister()) {
      LOG(FATAL) << "Unimplemented";
    } else if (source.IsQuickParameter()) {
      uint32_t argument_index = source.GetQuickParameterIndex();
      InvokeDexCallingConvention calling_convention;
      __ Mov(destination.AsRegisterPairLow<Register>(),
             calling_convention.GetRegisterAt(argument_index));
      __ LoadFromOffset(kLoadWord, destination.AsRegisterPairHigh<Register>(),
             SP, calling_convention.GetStackOffsetOf(argument_index + 1) + GetFrameSize());
    } else {
      DCHECK(source.IsDoubleStackSlot());
      if (destination.AsRegisterPairLow<Register>() == R1) {
        DCHECK_EQ(destination.AsRegisterPairHigh<Register>(), R2);
        __ LoadFromOffset(kLoadWord, R1, SP, source.GetStackIndex());
        __ LoadFromOffset(kLoadWord, R2, SP, source.GetHighStackIndex(kArmWordSize));
      } else {
        __ LoadFromOffset(kLoadWordPair, destination.AsRegisterPairLow<Register>(),
                          SP, source.GetStackIndex());
      }
    }
  } else if (destination.IsFpuRegister()) {
    if (source.IsDoubleStackSlot()) {
      __ vldrd(destination.As<DRegister>(), Address(SP, source.GetStackIndex()));
    } else {
      LOG(FATAL) << "Unimplemented";
    }
  } else if (destination.IsQuickParameter()) {
    InvokeDexCallingConvention calling_convention;
    uint32_t argument_index = destination.GetQuickParameterIndex();
    if (source.IsRegisterPair()) {
      __ Mov(calling_convention.GetRegisterAt(argument_index),
             source.AsRegisterPairLow<Register>());
      __ StoreToOffset(kStoreWord, source.AsRegisterPairHigh<Register>(),
             SP, calling_convention.GetStackOffsetOf(argument_index + 1));
    } else if (source.IsFpuRegister()) {
      LOG(FATAL) << "Unimplemented";
    } else {
      DCHECK(source.IsDoubleStackSlot());
      __ LoadFromOffset(kLoadWord, calling_convention.GetRegisterAt(argument_index), SP, source.GetStackIndex());
      __ LoadFromOffset(kLoadWord, R0, SP, source.GetHighStackIndex(kArmWordSize));
      __ StoreToOffset(kStoreWord, R0, SP, calling_convention.GetStackOffsetOf(argument_index + 1));
    }
  } else {
    DCHECK(destination.IsDoubleStackSlot());
    if (source.IsRegisterPair()) {
      if (source.AsRegisterPairLow<Register>() == R1) {
        DCHECK_EQ(source.AsRegisterPairHigh<Register>(), R2);
        __ StoreToOffset(kStoreWord, R1, SP, destination.GetStackIndex());
        __ StoreToOffset(kStoreWord, R2, SP, destination.GetHighStackIndex(kArmWordSize));
      } else {
        __ StoreToOffset(kStoreWordPair, source.AsRegisterPairLow<Register>(),
                         SP, destination.GetStackIndex());
      }
    } else if (source.IsQuickParameter()) {
      InvokeDexCallingConvention calling_convention;
      uint32_t argument_index = source.GetQuickParameterIndex();
      __ StoreToOffset(kStoreWord, calling_convention.GetRegisterAt(argument_index),
             SP, destination.GetStackIndex());
      __ LoadFromOffset(kLoadWord, R0,
             SP, calling_convention.GetStackOffsetOf(argument_index + 1) + GetFrameSize());
      __ StoreToOffset(kStoreWord, R0, SP, destination.GetHighStackIndex(kArmWordSize));
    } else if (source.IsFpuRegister()) {
      __ vstrd(source.As<DRegister>(), Address(SP, destination.GetStackIndex()));
    } else {
      DCHECK(source.IsDoubleStackSlot());
      __ LoadFromOffset(kLoadWord, IP, SP, source.GetStackIndex());
      __ StoreToOffset(kStoreWord, IP, SP, destination.GetStackIndex());
      __ LoadFromOffset(kLoadWord, IP, SP, source.GetHighStackIndex(kArmWordSize));
      __ StoreToOffset(kStoreWord, IP, SP, destination.GetHighStackIndex(kArmWordSize));
    }
  }
}

void CodeGeneratorARM::Move(HInstruction* instruction, Location location, HInstruction* move_for) {
  LocationSummary* locations = instruction->GetLocations();
  if (locations != nullptr && locations->Out().Equals(location)) {
    return;
  }

  if (instruction->IsIntConstant()) {
    int32_t value = instruction->AsIntConstant()->GetValue();
    if (location.IsRegister()) {
      __ LoadImmediate(location.As<Register>(), value);
    } else {
      DCHECK(location.IsStackSlot());
      __ LoadImmediate(IP, value);
      __ StoreToOffset(kStoreWord, IP, SP, location.GetStackIndex());
    }
  } else if (instruction->IsLongConstant()) {
    int64_t value = instruction->AsLongConstant()->GetValue();
    if (location.IsRegisterPair()) {
      __ LoadImmediate(location.AsRegisterPairLow<Register>(), Low32Bits(value));
      __ LoadImmediate(location.AsRegisterPairHigh<Register>(), High32Bits(value));
    } else {
      DCHECK(location.IsDoubleStackSlot());
      __ LoadImmediate(IP, Low32Bits(value));
      __ StoreToOffset(kStoreWord, IP, SP, location.GetStackIndex());
      __ LoadImmediate(IP, High32Bits(value));
      __ StoreToOffset(kStoreWord, IP, SP, location.GetHighStackIndex(kArmWordSize));
    }
  } else if (instruction->IsLoadLocal()) {
    uint32_t stack_slot = GetStackSlot(instruction->AsLoadLocal()->GetLocal());
    switch (instruction->GetType()) {
      case Primitive::kPrimBoolean:
      case Primitive::kPrimByte:
      case Primitive::kPrimChar:
      case Primitive::kPrimShort:
      case Primitive::kPrimInt:
      case Primitive::kPrimNot:
      case Primitive::kPrimFloat:
        Move32(location, Location::StackSlot(stack_slot));
        break;

      case Primitive::kPrimLong:
      case Primitive::kPrimDouble:
        Move64(location, Location::DoubleStackSlot(stack_slot));
        break;

      default:
        LOG(FATAL) << "Unexpected type " << instruction->GetType();
    }
  } else {
    DCHECK((instruction->GetNext() == move_for) || instruction->GetNext()->IsTemporary());
    switch (instruction->GetType()) {
      case Primitive::kPrimBoolean:
      case Primitive::kPrimByte:
      case Primitive::kPrimChar:
      case Primitive::kPrimShort:
      case Primitive::kPrimNot:
      case Primitive::kPrimInt:
      case Primitive::kPrimFloat:
        Move32(location, locations->Out());
        break;

      case Primitive::kPrimLong:
      case Primitive::kPrimDouble:
        Move64(location, locations->Out());
        break;

      default:
        LOG(FATAL) << "Unexpected type " << instruction->GetType();
    }
  }
}

void LocationsBuilderARM::VisitGoto(HGoto* got) {
  got->SetLocations(nullptr);
}

void InstructionCodeGeneratorARM::VisitGoto(HGoto* got) {
  HBasicBlock* successor = got->GetSuccessor();
  DCHECK(!successor->IsExitBlock());

  HBasicBlock* block = got->GetBlock();
  HInstruction* previous = got->GetPrevious();

  HLoopInformation* info = block->GetLoopInformation();
  if (info != nullptr && info->IsBackEdge(block) && info->HasSuspendCheck()) {
    codegen_->ClearSpillSlotsFromLoopPhisInStackMap(info->GetSuspendCheck());
    GenerateSuspendCheck(info->GetSuspendCheck(), successor);
    return;
  }

  if (block->IsEntryBlock() && (previous != nullptr) && previous->IsSuspendCheck()) {
    GenerateSuspendCheck(previous->AsSuspendCheck(), nullptr);
  }
  if (!codegen_->GoesToNextBlock(got->GetBlock(), successor)) {
    __ b(codegen_->GetLabelOf(successor));
  }
}

void LocationsBuilderARM::VisitExit(HExit* exit) {
  exit->SetLocations(nullptr);
}

void InstructionCodeGeneratorARM::VisitExit(HExit* exit) {
  if (kIsDebugBuild) {
    __ Comment("Unreachable");
    __ bkpt(0);
  }
}

void LocationsBuilderARM::VisitIf(HIf* if_instr) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(if_instr, LocationSummary::kNoCall);
  HInstruction* cond = if_instr->InputAt(0);
  if (!cond->IsCondition() || cond->AsCondition()->NeedsMaterialization()) {
    locations->SetInAt(0, Location::RequiresRegister());
  }
}

void InstructionCodeGeneratorARM::VisitIf(HIf* if_instr) {
  HInstruction* cond = if_instr->InputAt(0);
  if (cond->IsIntConstant()) {
    // Constant condition, statically compared against 1.
    int32_t cond_value = cond->AsIntConstant()->GetValue();
    if (cond_value == 1) {
      if (!codegen_->GoesToNextBlock(if_instr->GetBlock(),
                                     if_instr->IfTrueSuccessor())) {
        __ b(codegen_->GetLabelOf(if_instr->IfTrueSuccessor()));
      }
      return;
    } else {
      DCHECK_EQ(cond_value, 0);
    }
  } else {
    if (!cond->IsCondition() || cond->AsCondition()->NeedsMaterialization()) {
      // Condition has been materialized, compare the output to 0
      DCHECK(if_instr->GetLocations()->InAt(0).IsRegister());
      __ cmp(if_instr->GetLocations()->InAt(0).As<Register>(),
             ShifterOperand(0));
      __ b(codegen_->GetLabelOf(if_instr->IfTrueSuccessor()), NE);
    } else {
      // Condition has not been materialized, use its inputs as the
      // comparison and its condition as the branch condition.
      LocationSummary* locations = cond->GetLocations();
      if (locations->InAt(1).IsRegister()) {
        __ cmp(locations->InAt(0).As<Register>(),
               ShifterOperand(locations->InAt(1).As<Register>()));
      } else {
        DCHECK(locations->InAt(1).IsConstant());
        int32_t value =
            locations->InAt(1).GetConstant()->AsIntConstant()->GetValue();
        ShifterOperand operand;
        if (ShifterOperand::CanHoldArm(value, &operand)) {
          __ cmp(locations->InAt(0).As<Register>(), ShifterOperand(value));
        } else {
          Register temp = IP;
          __ LoadImmediate(temp, value);
          __ cmp(locations->InAt(0).As<Register>(), ShifterOperand(temp));
        }
      }
      __ b(codegen_->GetLabelOf(if_instr->IfTrueSuccessor()),
           ARMCondition(cond->AsCondition()->GetCondition()));
    }
  }
  if (!codegen_->GoesToNextBlock(if_instr->GetBlock(),
                                 if_instr->IfFalseSuccessor())) {
    __ b(codegen_->GetLabelOf(if_instr->IfFalseSuccessor()));
  }
}


void LocationsBuilderARM::VisitCondition(HCondition* comp) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(comp, LocationSummary::kNoCall);
  locations->SetInAt(0, Location::RequiresRegister());
  locations->SetInAt(1, Location::RegisterOrConstant(comp->InputAt(1)));
  if (comp->NeedsMaterialization()) {
    locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
  }
}

void InstructionCodeGeneratorARM::VisitCondition(HCondition* comp) {
  if (!comp->NeedsMaterialization()) return;

  LocationSummary* locations = comp->GetLocations();
  if (locations->InAt(1).IsRegister()) {
    __ cmp(locations->InAt(0).As<Register>(),
           ShifterOperand(locations->InAt(1).As<Register>()));
  } else {
    DCHECK(locations->InAt(1).IsConstant());
    int32_t value = locations->InAt(1).GetConstant()->AsIntConstant()->GetValue();
    ShifterOperand operand;
    if (ShifterOperand::CanHoldArm(value, &operand)) {
      __ cmp(locations->InAt(0).As<Register>(), ShifterOperand(value));
    } else {
      Register temp = IP;
      __ LoadImmediate(temp, value);
      __ cmp(locations->InAt(0).As<Register>(), ShifterOperand(temp));
    }
  }
  __ it(ARMCondition(comp->GetCondition()), kItElse);
  __ mov(locations->Out().As<Register>(), ShifterOperand(1),
         ARMCondition(comp->GetCondition()));
  __ mov(locations->Out().As<Register>(), ShifterOperand(0),
         ARMOppositeCondition(comp->GetCondition()));
}

void LocationsBuilderARM::VisitEqual(HEqual* comp) {
  VisitCondition(comp);
}

void InstructionCodeGeneratorARM::VisitEqual(HEqual* comp) {
  VisitCondition(comp);
}

void LocationsBuilderARM::VisitNotEqual(HNotEqual* comp) {
  VisitCondition(comp);
}

void InstructionCodeGeneratorARM::VisitNotEqual(HNotEqual* comp) {
  VisitCondition(comp);
}

void LocationsBuilderARM::VisitLessThan(HLessThan* comp) {
  VisitCondition(comp);
}

void InstructionCodeGeneratorARM::VisitLessThan(HLessThan* comp) {
  VisitCondition(comp);
}

void LocationsBuilderARM::VisitLessThanOrEqual(HLessThanOrEqual* comp) {
  VisitCondition(comp);
}

void InstructionCodeGeneratorARM::VisitLessThanOrEqual(HLessThanOrEqual* comp) {
  VisitCondition(comp);
}

void LocationsBuilderARM::VisitGreaterThan(HGreaterThan* comp) {
  VisitCondition(comp);
}

void InstructionCodeGeneratorARM::VisitGreaterThan(HGreaterThan* comp) {
  VisitCondition(comp);
}

void LocationsBuilderARM::VisitGreaterThanOrEqual(HGreaterThanOrEqual* comp) {
  VisitCondition(comp);
}

void InstructionCodeGeneratorARM::VisitGreaterThanOrEqual(HGreaterThanOrEqual* comp) {
  VisitCondition(comp);
}

void LocationsBuilderARM::VisitLocal(HLocal* local) {
  local->SetLocations(nullptr);
}

void InstructionCodeGeneratorARM::VisitLocal(HLocal* local) {
  DCHECK_EQ(local->GetBlock(), GetGraph()->GetEntryBlock());
}

void LocationsBuilderARM::VisitLoadLocal(HLoadLocal* load) {
  load->SetLocations(nullptr);
}

void InstructionCodeGeneratorARM::VisitLoadLocal(HLoadLocal* load) {
  // Nothing to do, this is driven by the code generator.
}

void LocationsBuilderARM::VisitStoreLocal(HStoreLocal* store) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(store, LocationSummary::kNoCall);
  switch (store->InputAt(1)->GetType()) {
    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
    case Primitive::kPrimInt:
    case Primitive::kPrimNot:
    case Primitive::kPrimFloat:
      locations->SetInAt(1, Location::StackSlot(codegen_->GetStackSlot(store->GetLocal())));
      break;

    case Primitive::kPrimLong:
    case Primitive::kPrimDouble:
      locations->SetInAt(1, Location::DoubleStackSlot(codegen_->GetStackSlot(store->GetLocal())));
      break;

    default:
      LOG(FATAL) << "Unexpected local type " << store->InputAt(1)->GetType();
  }
}

void InstructionCodeGeneratorARM::VisitStoreLocal(HStoreLocal* store) {
}

void LocationsBuilderARM::VisitIntConstant(HIntConstant* constant) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(constant, LocationSummary::kNoCall);
  locations->SetOut(Location::ConstantLocation(constant));
}

void InstructionCodeGeneratorARM::VisitIntConstant(HIntConstant* constant) {
  // Will be generated at use site.
}

void LocationsBuilderARM::VisitLongConstant(HLongConstant* constant) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(constant, LocationSummary::kNoCall);
  locations->SetOut(Location::ConstantLocation(constant));
}

void InstructionCodeGeneratorARM::VisitLongConstant(HLongConstant* constant) {
  // Will be generated at use site.
}

void LocationsBuilderARM::VisitReturnVoid(HReturnVoid* ret) {
  ret->SetLocations(nullptr);
}

void InstructionCodeGeneratorARM::VisitReturnVoid(HReturnVoid* ret) {
  codegen_->GenerateFrameExit();
}

void LocationsBuilderARM::VisitReturn(HReturn* ret) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(ret, LocationSummary::kNoCall);
  switch (ret->InputAt(0)->GetType()) {
    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
    case Primitive::kPrimInt:
    case Primitive::kPrimNot:
    case Primitive::kPrimFloat:
      locations->SetInAt(0, Location::RegisterLocation(R0));
      break;

    case Primitive::kPrimLong:
    case Primitive::kPrimDouble:
      locations->SetInAt(0, Location::RegisterPairLocation(R0, R1));
      break;

    default:
      LOG(FATAL) << "Unimplemented return type " << ret->InputAt(0)->GetType();
  }
}

void InstructionCodeGeneratorARM::VisitReturn(HReturn* ret) {
  if (kIsDebugBuild) {
    switch (ret->InputAt(0)->GetType()) {
      case Primitive::kPrimBoolean:
      case Primitive::kPrimByte:
      case Primitive::kPrimChar:
      case Primitive::kPrimShort:
      case Primitive::kPrimInt:
      case Primitive::kPrimNot:
      case Primitive::kPrimFloat:
        DCHECK_EQ(ret->GetLocations()->InAt(0).As<Register>(), R0);
        break;

      case Primitive::kPrimLong:
      case Primitive::kPrimDouble:
        DCHECK_EQ(ret->GetLocations()->InAt(0).AsRegisterPairLow<Register>(), R0);
        DCHECK_EQ(ret->GetLocations()->InAt(0).AsRegisterPairHigh<Register>(), R1);
        break;

      default:
        LOG(FATAL) << "Unimplemented return type " << ret->InputAt(0)->GetType();
    }
  }
  codegen_->GenerateFrameExit();
}

void LocationsBuilderARM::VisitInvokeStatic(HInvokeStatic* invoke) {
  HandleInvoke(invoke);
}

void InstructionCodeGeneratorARM::LoadCurrentMethod(Register reg) {
  __ LoadFromOffset(kLoadWord, reg, SP, kCurrentMethodStackOffset);
}

void InstructionCodeGeneratorARM::VisitInvokeStatic(HInvokeStatic* invoke) {
  Register temp = invoke->GetLocations()->GetTemp(0).As<Register>();
  uint32_t heap_reference_size = sizeof(mirror::HeapReference<mirror::Object>);
  size_t index_in_cache = mirror::Array::DataOffset(heap_reference_size).Int32Value() +
      invoke->GetIndexInDexCache() * kArmWordSize;

  // TODO: Implement all kinds of calls:
  // 1) boot -> boot
  // 2) app -> boot
  // 3) app -> app
  //
  // Currently we implement the app -> app logic, which looks up in the resolve cache.

  // temp = method;
  LoadCurrentMethod(temp);
  // temp = temp->dex_cache_resolved_methods_;
  __ LoadFromOffset(kLoadWord, temp, temp, mirror::ArtMethod::DexCacheResolvedMethodsOffset().Int32Value());
  // temp = temp[index_in_cache]
  __ LoadFromOffset(kLoadWord, temp, temp, index_in_cache);
  // LR = temp[offset_of_quick_compiled_code]
  __ LoadFromOffset(kLoadWord, LR, temp,
                     mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset().Int32Value());
  // LR()
  __ blx(LR);

  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
  DCHECK(!codegen_->IsLeafMethod());
}

void LocationsBuilderARM::VisitInvokeVirtual(HInvokeVirtual* invoke) {
  HandleInvoke(invoke);
}

void LocationsBuilderARM::HandleInvoke(HInvoke* invoke) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(invoke, LocationSummary::kCall);
  locations->AddTemp(Location::RegisterLocation(R0));

  InvokeDexCallingConventionVisitor calling_convention_visitor;
  for (size_t i = 0; i < invoke->InputCount(); i++) {
    HInstruction* input = invoke->InputAt(i);
    locations->SetInAt(i, calling_convention_visitor.GetNextLocation(input->GetType()));
  }

  switch (invoke->GetType()) {
    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
    case Primitive::kPrimInt:
    case Primitive::kPrimNot:
    case Primitive::kPrimFloat:
      locations->SetOut(Location::RegisterLocation(R0));
      break;

    case Primitive::kPrimLong:
    case Primitive::kPrimDouble:
      locations->SetOut(Location::RegisterPairLocation(R0, R1));
      break;

    case Primitive::kPrimVoid:
      break;
  }
}


void InstructionCodeGeneratorARM::VisitInvokeVirtual(HInvokeVirtual* invoke) {
  Register temp = invoke->GetLocations()->GetTemp(0).As<Register>();
  uint32_t method_offset = mirror::Class::EmbeddedVTableOffset().Uint32Value() +
          invoke->GetVTableIndex() * sizeof(mirror::Class::VTableEntry);
  LocationSummary* locations = invoke->GetLocations();
  Location receiver = locations->InAt(0);
  uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
  // temp = object->GetClass();
  if (receiver.IsStackSlot()) {
    __ LoadFromOffset(kLoadWord, temp, SP, receiver.GetStackIndex());
    __ LoadFromOffset(kLoadWord, temp, temp, class_offset);
  } else {
    __ LoadFromOffset(kLoadWord, temp, receiver.As<Register>(), class_offset);
  }
  // temp = temp->GetMethodAt(method_offset);
  uint32_t entry_point = mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset().Int32Value();
  __ LoadFromOffset(kLoadWord, temp, temp, method_offset);
  // LR = temp->GetEntryPoint();
  __ LoadFromOffset(kLoadWord, LR, temp, entry_point);
  // LR();
  __ blx(LR);
  DCHECK(!codegen_->IsLeafMethod());
  codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
}

void LocationsBuilderARM::VisitAdd(HAdd* add) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(add, LocationSummary::kNoCall);
  switch (add->GetResultType()) {
    case Primitive::kPrimInt:
    case Primitive::kPrimLong: {
      bool output_overlaps = (add->GetResultType() == Primitive::kPrimLong);
      locations->SetInAt(0, Location::RequiresRegister());
      locations->SetInAt(1, Location::RegisterOrConstant(add->InputAt(1)));
      locations->SetOut(Location::RequiresRegister(), output_overlaps);
      break;
    }

    case Primitive::kPrimFloat:
    case Primitive::kPrimDouble: {
      locations->SetInAt(0, Location::RequiresFpuRegister());
      locations->SetInAt(1, Location::RequiresFpuRegister());
      locations->SetOut(Location::RequiresFpuRegister());
      break;
    }

    default:
      LOG(FATAL) << "Unexpected add type " << add->GetResultType();
  }
}

void InstructionCodeGeneratorARM::VisitAdd(HAdd* add) {
  LocationSummary* locations = add->GetLocations();
  Location out = locations->Out();
  Location first = locations->InAt(0);
  Location second = locations->InAt(1);
  switch (add->GetResultType()) {
    case Primitive::kPrimInt:
      if (second.IsRegister()) {
        __ add(out.As<Register>(), first.As<Register>(), ShifterOperand(second.As<Register>()));
      } else {
        __ AddConstant(out.As<Register>(),
                       first.As<Register>(),
                       second.GetConstant()->AsIntConstant()->GetValue());
      }
      break;

    case Primitive::kPrimLong:
      __ adds(out.AsRegisterPairLow<Register>(),
              first.AsRegisterPairLow<Register>(),
              ShifterOperand(second.AsRegisterPairLow<Register>()));
      __ adc(out.AsRegisterPairHigh<Register>(),
             first.AsRegisterPairHigh<Register>(),
             ShifterOperand(second.AsRegisterPairHigh<Register>()));
      break;

    case Primitive::kPrimFloat:
      __ vadds(FromDToLowS(out.As<DRegister>()),
               FromDToLowS(first.As<DRegister>()),
               FromDToLowS(second.As<DRegister>()));
      break;

    case Primitive::kPrimDouble:
      __ vaddd(out.As<DRegister>(), first.As<DRegister>(), second.As<DRegister>());
      break;

    default:
      LOG(FATAL) << "Unexpected add type " << add->GetResultType();
  }
}

void LocationsBuilderARM::VisitSub(HSub* sub) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(sub, LocationSummary::kNoCall);
  switch (sub->GetResultType()) {
    case Primitive::kPrimInt:
    case Primitive::kPrimLong: {
      bool output_overlaps = (sub->GetResultType() == Primitive::kPrimLong);
      locations->SetInAt(0, Location::RequiresRegister());
      locations->SetInAt(1, Location::RegisterOrConstant(sub->InputAt(1)));
      locations->SetOut(Location::RequiresRegister(), output_overlaps);
      break;
    }

    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
      LOG(FATAL) << "Unexpected sub type " << sub->GetResultType();
      break;

    default:
      LOG(FATAL) << "Unimplemented sub type " << sub->GetResultType();
  }
}

void InstructionCodeGeneratorARM::VisitSub(HSub* sub) {
  LocationSummary* locations = sub->GetLocations();
  switch (sub->GetResultType()) {
    case Primitive::kPrimInt: {
      if (locations->InAt(1).IsRegister()) {
        __ sub(locations->Out().As<Register>(),
               locations->InAt(0).As<Register>(),
               ShifterOperand(locations->InAt(1).As<Register>()));
      } else {
        __ AddConstant(locations->Out().As<Register>(),
                       locations->InAt(0).As<Register>(),
                       -locations->InAt(1).GetConstant()->AsIntConstant()->GetValue());
      }
      break;
    }

    case Primitive::kPrimLong:
      __ subs(locations->Out().AsRegisterPairLow<Register>(),
              locations->InAt(0).AsRegisterPairLow<Register>(),
              ShifterOperand(locations->InAt(1).AsRegisterPairLow<Register>()));
      __ sbc(locations->Out().AsRegisterPairHigh<Register>(),
             locations->InAt(0).AsRegisterPairHigh<Register>(),
             ShifterOperand(locations->InAt(1).AsRegisterPairHigh<Register>()));
      break;

    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
      LOG(FATAL) << "Unexpected sub type " << sub->GetResultType();
      break;

    default:
      LOG(FATAL) << "Unimplemented sub type " << sub->GetResultType();
  }
}

void LocationsBuilderARM::VisitMul(HMul* mul) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(mul, LocationSummary::kNoCall);
  switch (mul->GetResultType()) {
    case Primitive::kPrimInt:
    case Primitive::kPrimLong:  {
      locations->SetInAt(0, Location::RequiresRegister());
      locations->SetInAt(1, Location::RequiresRegister());
      locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
      break;
    }

    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
      LOG(FATAL) << "Unexpected mul type " << mul->GetResultType();
      break;

    default:
      LOG(FATAL) << "Unimplemented mul type " << mul->GetResultType();
  }
}

void InstructionCodeGeneratorARM::VisitMul(HMul* mul) {
  LocationSummary* locations = mul->GetLocations();
  Location out = locations->Out();
  Location first = locations->InAt(0);
  Location second = locations->InAt(1);
  switch (mul->GetResultType()) {
    case Primitive::kPrimInt: {
      __ mul(out.As<Register>(), first.As<Register>(), second.As<Register>());
      break;
    }
    case Primitive::kPrimLong: {
      Register out_hi = out.AsRegisterPairHigh<Register>();
      Register out_lo = out.AsRegisterPairLow<Register>();
      Register in1_hi = first.AsRegisterPairHigh<Register>();
      Register in1_lo = first.AsRegisterPairLow<Register>();
      Register in2_hi = second.AsRegisterPairHigh<Register>();
      Register in2_lo = second.AsRegisterPairLow<Register>();

      // Extra checks to protect caused by the existence of R1_R2.
      // The algorithm is wrong if out.hi is either in1.lo or in2.lo:
      // (e.g. in1=r0_r1, in2=r2_r3 and out=r1_r2);
      DCHECK_NE(out_hi, in1_lo);
      DCHECK_NE(out_hi, in2_lo);

      // input: in1 - 64 bits, in2 - 64 bits
      // output: out
      // formula: out.hi : out.lo = (in1.lo * in2.hi + in1.hi * in2.lo)* 2^32 + in1.lo * in2.lo
      // parts: out.hi = in1.lo * in2.hi + in1.hi * in2.lo + (in1.lo * in2.lo)[63:32]
      // parts: out.lo = (in1.lo * in2.lo)[31:0]

      // IP <- in1.lo * in2.hi
      __ mul(IP, in1_lo, in2_hi);
      // out.hi <- in1.lo * in2.hi + in1.hi * in2.lo
      __ mla(out_hi, in1_hi, in2_lo, IP);
      // out.lo <- (in1.lo * in2.lo)[31:0];
      __ umull(out_lo, IP, in1_lo, in2_lo);
      // out.hi <- in2.hi * in1.lo +  in2.lo * in1.hi + (in1.lo * in2.lo)[63:32]
      __ add(out_hi, out_hi, ShifterOperand(IP));
      break;
    }
    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte:
    case Primitive::kPrimChar:
    case Primitive::kPrimShort:
      LOG(FATAL) << "Unexpected mul type " << mul->GetResultType();
      break;

    default:
      LOG(FATAL) << "Unimplemented mul type " << mul->GetResultType();
  }
}

void LocationsBuilderARM::VisitNewInstance(HNewInstance* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kCall);
  InvokeRuntimeCallingConvention calling_convention;
  locations->AddTemp(Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
  locations->AddTemp(Location::RegisterLocation(calling_convention.GetRegisterAt(1)));
  locations->SetOut(Location::RegisterLocation(R0));
}

void InstructionCodeGeneratorARM::VisitNewInstance(HNewInstance* instruction) {
  InvokeRuntimeCallingConvention calling_convention;
  LoadCurrentMethod(calling_convention.GetRegisterAt(1));
  __ LoadImmediate(calling_convention.GetRegisterAt(0), instruction->GetTypeIndex());

  int32_t offset = QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pAllocObjectWithAccessCheck).Int32Value();
  __ LoadFromOffset(kLoadWord, LR, TR, offset);
  __ blx(LR);

  codegen_->RecordPcInfo(instruction, instruction->GetDexPc());
  DCHECK(!codegen_->IsLeafMethod());
}

void LocationsBuilderARM::VisitParameterValue(HParameterValue* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  Location location = parameter_visitor_.GetNextLocation(instruction->GetType());
  if (location.IsStackSlot()) {
    location = Location::StackSlot(location.GetStackIndex() + codegen_->GetFrameSize());
  } else if (location.IsDoubleStackSlot()) {
    location = Location::DoubleStackSlot(location.GetStackIndex() + codegen_->GetFrameSize());
  }
  locations->SetOut(location);
}

void InstructionCodeGeneratorARM::VisitParameterValue(HParameterValue* instruction) {
  // Nothing to do, the parameter is already at its location.
}

void LocationsBuilderARM::VisitNot(HNot* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  locations->SetInAt(0, Location::RequiresRegister());
  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
}

void InstructionCodeGeneratorARM::VisitNot(HNot* instruction) {
  LocationSummary* locations = instruction->GetLocations();
  __ eor(locations->Out().As<Register>(),
         locations->InAt(0).As<Register>(), ShifterOperand(1));
}

void LocationsBuilderARM::VisitCompare(HCompare* compare) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(compare, LocationSummary::kNoCall);
  locations->SetInAt(0, Location::RequiresRegister());
  locations->SetInAt(1, Location::RequiresRegister());
  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
}

void InstructionCodeGeneratorARM::VisitCompare(HCompare* compare) {
  Label greater, done;
  LocationSummary* locations = compare->GetLocations();
  switch (compare->InputAt(0)->GetType()) {
    case Primitive::kPrimLong: {
      Register output = locations->Out().As<Register>();
      Location left = locations->InAt(0);
      Location right = locations->InAt(1);
      Label less, greater, done;
      __ cmp(left.AsRegisterPairHigh<Register>(),
             ShifterOperand(right.AsRegisterPairHigh<Register>()));  // Signed compare.
      __ b(&less, LT);
      __ b(&greater, GT);
      // Do LoadImmediate before any `cmp`, as LoadImmediate might affect
      // the status flags.
      __ LoadImmediate(output, 0);
      __ cmp(left.AsRegisterPairLow<Register>(),
             ShifterOperand(right.AsRegisterPairLow<Register>()));  // Unsigned compare.
      __ b(&done, EQ);
      __ b(&less, CC);

      __ Bind(&greater);
      __ LoadImmediate(output, 1);
      __ b(&done);

      __ Bind(&less);
      __ LoadImmediate(output, -1);

      __ Bind(&done);
      break;
    }
    default:
      LOG(FATAL) << "Unimplemented compare type " << compare->InputAt(0)->GetType();
  }
}

void LocationsBuilderARM::VisitPhi(HPhi* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  for (size_t i = 0, e = instruction->InputCount(); i < e; ++i) {
    locations->SetInAt(i, Location::Any());
  }
  locations->SetOut(Location::Any());
}

void InstructionCodeGeneratorARM::VisitPhi(HPhi* instruction) {
  LOG(FATAL) << "Unreachable";
}

void LocationsBuilderARM::VisitInstanceFieldSet(HInstanceFieldSet* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  bool is_object_type = instruction->GetFieldType() == Primitive::kPrimNot;
  locations->SetInAt(0, Location::RequiresRegister());
  locations->SetInAt(1, Location::RequiresRegister());
  // Temporary registers for the write barrier.
  if (is_object_type) {
    locations->AddTemp(Location::RequiresRegister());
    locations->AddTemp(Location::RequiresRegister());
  }
}

void InstructionCodeGeneratorARM::VisitInstanceFieldSet(HInstanceFieldSet* instruction) {
  LocationSummary* locations = instruction->GetLocations();
  Register obj = locations->InAt(0).As<Register>();
  uint32_t offset = instruction->GetFieldOffset().Uint32Value();
  Primitive::Type field_type = instruction->GetFieldType();

  switch (field_type) {
    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte: {
      Register value = locations->InAt(1).As<Register>();
      __ StoreToOffset(kStoreByte, value, obj, offset);
      break;
    }

    case Primitive::kPrimShort:
    case Primitive::kPrimChar: {
      Register value = locations->InAt(1).As<Register>();
      __ StoreToOffset(kStoreHalfword, value, obj, offset);
      break;
    }

    case Primitive::kPrimInt:
    case Primitive::kPrimNot: {
      Register value = locations->InAt(1).As<Register>();
      __ StoreToOffset(kStoreWord, value, obj, offset);
      if (field_type == Primitive::kPrimNot) {
        Register temp = locations->GetTemp(0).As<Register>();
        Register card = locations->GetTemp(1).As<Register>();
        codegen_->MarkGCCard(temp, card, obj, value);
      }
      break;
    }

    case Primitive::kPrimLong: {
      Location value = locations->InAt(1);
      __ StoreToOffset(kStoreWordPair, value.AsRegisterPairLow<Register>(), obj, offset);
      break;
    }

    case Primitive::kPrimFloat:
    case Primitive::kPrimDouble:
      LOG(FATAL) << "Unimplemented register type " << field_type;
      UNREACHABLE();
    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unreachable type " << field_type;
      UNREACHABLE();
  }
}

void LocationsBuilderARM::VisitInstanceFieldGet(HInstanceFieldGet* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  locations->SetInAt(0, Location::RequiresRegister());
  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
}

void InstructionCodeGeneratorARM::VisitInstanceFieldGet(HInstanceFieldGet* instruction) {
  LocationSummary* locations = instruction->GetLocations();
  Register obj = locations->InAt(0).As<Register>();
  uint32_t offset = instruction->GetFieldOffset().Uint32Value();

  switch (instruction->GetType()) {
    case Primitive::kPrimBoolean: {
      Register out = locations->Out().As<Register>();
      __ LoadFromOffset(kLoadUnsignedByte, out, obj, offset);
      break;
    }

    case Primitive::kPrimByte: {
      Register out = locations->Out().As<Register>();
      __ LoadFromOffset(kLoadSignedByte, out, obj, offset);
      break;
    }

    case Primitive::kPrimShort: {
      Register out = locations->Out().As<Register>();
      __ LoadFromOffset(kLoadSignedHalfword, out, obj, offset);
      break;
    }

    case Primitive::kPrimChar: {
      Register out = locations->Out().As<Register>();
      __ LoadFromOffset(kLoadUnsignedHalfword, out, obj, offset);
      break;
    }

    case Primitive::kPrimInt:
    case Primitive::kPrimNot: {
      Register out = locations->Out().As<Register>();
      __ LoadFromOffset(kLoadWord, out, obj, offset);
      break;
    }

    case Primitive::kPrimLong: {
      // TODO: support volatile.
      Location out = locations->Out();
      __ LoadFromOffset(kLoadWordPair, out.AsRegisterPairLow<Register>(), obj, offset);
      break;
    }

    case Primitive::kPrimFloat:
    case Primitive::kPrimDouble:
      LOG(FATAL) << "Unimplemented register type " << instruction->GetType();
      UNREACHABLE();
    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unreachable type " << instruction->GetType();
      UNREACHABLE();
  }
}

void LocationsBuilderARM::VisitNullCheck(HNullCheck* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  locations->SetInAt(0, Location::RequiresRegister());
  if (instruction->HasUses()) {
    locations->SetOut(Location::SameAsFirstInput());
  }
}

void InstructionCodeGeneratorARM::VisitNullCheck(HNullCheck* instruction) {
  SlowPathCodeARM* slow_path = new (GetGraph()->GetArena()) NullCheckSlowPathARM(instruction);
  codegen_->AddSlowPath(slow_path);

  LocationSummary* locations = instruction->GetLocations();
  Location obj = locations->InAt(0);

  if (obj.IsRegister()) {
    __ cmp(obj.As<Register>(), ShifterOperand(0));
    __ b(slow_path->GetEntryLabel(), EQ);
  } else {
    DCHECK(obj.IsConstant()) << obj;
    DCHECK_EQ(obj.GetConstant()->AsIntConstant()->GetValue(), 0);
    __ b(slow_path->GetEntryLabel());
  }
}

void LocationsBuilderARM::VisitArrayGet(HArrayGet* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  locations->SetInAt(0, Location::RequiresRegister());
  locations->SetInAt(1, Location::RegisterOrConstant(instruction->InputAt(1)));
  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
}

void InstructionCodeGeneratorARM::VisitArrayGet(HArrayGet* instruction) {
  LocationSummary* locations = instruction->GetLocations();
  Register obj = locations->InAt(0).As<Register>();
  Location index = locations->InAt(1);

  switch (instruction->GetType()) {
    case Primitive::kPrimBoolean: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(uint8_t)).Uint32Value();
      Register out = locations->Out().As<Register>();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_1) + data_offset;
        __ LoadFromOffset(kLoadUnsignedByte, out, obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>()));
        __ LoadFromOffset(kLoadUnsignedByte, out, IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimByte: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(int8_t)).Uint32Value();
      Register out = locations->Out().As<Register>();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_1) + data_offset;
        __ LoadFromOffset(kLoadSignedByte, out, obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>()));
        __ LoadFromOffset(kLoadSignedByte, out, IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimShort: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(int16_t)).Uint32Value();
      Register out = locations->Out().As<Register>();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_2) + data_offset;
        __ LoadFromOffset(kLoadSignedHalfword, out, obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>(), LSL, TIMES_2));
        __ LoadFromOffset(kLoadSignedHalfword, out, IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimChar: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(uint16_t)).Uint32Value();
      Register out = locations->Out().As<Register>();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_2) + data_offset;
        __ LoadFromOffset(kLoadUnsignedHalfword, out, obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>(), LSL, TIMES_2));
        __ LoadFromOffset(kLoadUnsignedHalfword, out, IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimInt:
    case Primitive::kPrimNot: {
      DCHECK_EQ(sizeof(mirror::HeapReference<mirror::Object>), sizeof(int32_t));
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(int32_t)).Uint32Value();
      Register out = locations->Out().As<Register>();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_4) + data_offset;
        __ LoadFromOffset(kLoadWord, out, obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>(), LSL, TIMES_4));
        __ LoadFromOffset(kLoadWord, out, IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimLong: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(int64_t)).Uint32Value();
      Location out = locations->Out();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_8) + data_offset;
        __ LoadFromOffset(kLoadWordPair, out.AsRegisterPairLow<Register>(), obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>(), LSL, TIMES_8));
        __ LoadFromOffset(kLoadWordPair, out.AsRegisterPairLow<Register>(), IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimFloat:
    case Primitive::kPrimDouble:
      LOG(FATAL) << "Unimplemented register type " << instruction->GetType();
      UNREACHABLE();
    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unreachable type " << instruction->GetType();
      UNREACHABLE();
  }
}

void LocationsBuilderARM::VisitArraySet(HArraySet* instruction) {
  Primitive::Type value_type = instruction->GetComponentType();
  bool is_object = value_type == Primitive::kPrimNot;
  LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(
      instruction, is_object ? LocationSummary::kCall : LocationSummary::kNoCall);
  if (is_object) {
    InvokeRuntimeCallingConvention calling_convention;
    locations->SetInAt(0, Location::RegisterLocation(calling_convention.GetRegisterAt(0)));
    locations->SetInAt(1, Location::RegisterLocation(calling_convention.GetRegisterAt(1)));
    locations->SetInAt(2, Location::RegisterLocation(calling_convention.GetRegisterAt(2)));
  } else {
    locations->SetInAt(0, Location::RequiresRegister());
    locations->SetInAt(1, Location::RegisterOrConstant(instruction->InputAt(1)));
    locations->SetInAt(2, Location::RequiresRegister());
  }
}

void InstructionCodeGeneratorARM::VisitArraySet(HArraySet* instruction) {
  LocationSummary* locations = instruction->GetLocations();
  Register obj = locations->InAt(0).As<Register>();
  Location index = locations->InAt(1);
  Primitive::Type value_type = instruction->GetComponentType();

  switch (value_type) {
    case Primitive::kPrimBoolean:
    case Primitive::kPrimByte: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(uint8_t)).Uint32Value();
      Register value = locations->InAt(2).As<Register>();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_1) + data_offset;
        __ StoreToOffset(kStoreByte, value, obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>()));
        __ StoreToOffset(kStoreByte, value, IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimShort:
    case Primitive::kPrimChar: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(uint16_t)).Uint32Value();
      Register value = locations->InAt(2).As<Register>();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_2) + data_offset;
        __ StoreToOffset(kStoreHalfword, value, obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>(), LSL, TIMES_2));
        __ StoreToOffset(kStoreHalfword, value, IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimInt: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(int32_t)).Uint32Value();
      Register value = locations->InAt(2).As<Register>();
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_4) + data_offset;
        __ StoreToOffset(kStoreWord, value, obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>(), LSL, TIMES_4));
        __ StoreToOffset(kStoreWord, value, IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimNot: {
      int32_t offset = QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pAputObject).Int32Value();
      __ LoadFromOffset(kLoadWord, LR, TR, offset);
      __ blx(LR);
      codegen_->RecordPcInfo(instruction, instruction->GetDexPc());
      DCHECK(!codegen_->IsLeafMethod());
      break;
    }

    case Primitive::kPrimLong: {
      uint32_t data_offset = mirror::Array::DataOffset(sizeof(int64_t)).Uint32Value();
      Location value = locations->InAt(2);
      if (index.IsConstant()) {
        size_t offset = (index.GetConstant()->AsIntConstant()->GetValue() << TIMES_8) + data_offset;
        __ StoreToOffset(kStoreWordPair, value.AsRegisterPairLow<Register>(), obj, offset);
      } else {
        __ add(IP, obj, ShifterOperand(index.As<Register>(), LSL, TIMES_8));
        __ StoreToOffset(kStoreWordPair, value.AsRegisterPairLow<Register>(), IP, data_offset);
      }
      break;
    }

    case Primitive::kPrimFloat:
    case Primitive::kPrimDouble:
      LOG(FATAL) << "Unimplemented register type " << instruction->GetType();
      UNREACHABLE();
    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unreachable type " << instruction->GetType();
      UNREACHABLE();
  }
}

void LocationsBuilderARM::VisitArrayLength(HArrayLength* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  locations->SetInAt(0, Location::RequiresRegister());
  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
}

void InstructionCodeGeneratorARM::VisitArrayLength(HArrayLength* instruction) {
  LocationSummary* locations = instruction->GetLocations();
  uint32_t offset = mirror::Array::LengthOffset().Uint32Value();
  Register obj = locations->InAt(0).As<Register>();
  Register out = locations->Out().As<Register>();
  __ LoadFromOffset(kLoadWord, out, obj, offset);
}

void LocationsBuilderARM::VisitBoundsCheck(HBoundsCheck* instruction) {
  LocationSummary* locations =
      new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
  locations->SetInAt(0, Location::RequiresRegister());
  locations->SetInAt(1, Location::RequiresRegister());
  if (instruction->HasUses()) {
    locations->SetOut(Location::SameAsFirstInput());
  }
}

void InstructionCodeGeneratorARM::VisitBoundsCheck(HBoundsCheck* instruction) {
  LocationSummary* locations = instruction->GetLocations();
  SlowPathCodeARM* slow_path = new (GetGraph()->GetArena()) BoundsCheckSlowPathARM(
      instruction, locations->InAt(0), locations->InAt(1));
  codegen_->AddSlowPath(slow_path);

  Register index = locations->InAt(0).As<Register>();
  Register length = locations->InAt(1).As<Register>();

  __ cmp(index, ShifterOperand(length));
  __ b(slow_path->GetEntryLabel(), CS);
}

void CodeGeneratorARM::MarkGCCard(Register temp, Register card, Register object, Register value) {
  Label is_null;
  __ CompareAndBranchIfZero(value, &is_null);
  __ LoadFromOffset(kLoadWord, card, TR, Thread::CardTableOffset<kArmWordSize>().Int32Value());
  __ Lsr(temp, object, gc::accounting::CardTable::kCardShift);
  __ strb(card, Address(card, temp));
  __ Bind(&is_null);
}

void LocationsBuilderARM::VisitTemporary(HTemporary* temp) {
  temp->SetLocations(nullptr);
}

void InstructionCodeGeneratorARM::VisitTemporary(HTemporary* temp) {
  // Nothing to do, this is driven by the code generator.
}

void LocationsBuilderARM::VisitParallelMove(HParallelMove* instruction) {
  LOG(FATAL) << "Unreachable";
}

void InstructionCodeGeneratorARM::VisitParallelMove(HParallelMove* instruction) {
  codegen_->GetMoveResolver()->EmitNativeCode(instruction);
}

void LocationsBuilderARM::VisitSuspendCheck(HSuspendCheck* instruction) {
  new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kCallOnSlowPath);
}

void InstructionCodeGeneratorARM::VisitSuspendCheck(HSuspendCheck* instruction) {
  HBasicBlock* block = instruction->GetBlock();
  if (block->GetLoopInformation() != nullptr) {
    DCHECK(block->GetLoopInformation()->GetSuspendCheck() == instruction);
    // The back edge will generate the suspend check.
    return;
  }
  if (block->IsEntryBlock() && instruction->GetNext()->IsGoto()) {
    // The goto will generate the suspend check.
    return;
  }
  GenerateSuspendCheck(instruction, nullptr);
}

void InstructionCodeGeneratorARM::GenerateSuspendCheck(HSuspendCheck* instruction,
                                                       HBasicBlock* successor) {
  SuspendCheckSlowPathARM* slow_path =
      new (GetGraph()->GetArena()) SuspendCheckSlowPathARM(instruction, successor);
  codegen_->AddSlowPath(slow_path);

  __ subs(R4, R4, ShifterOperand(1));
  if (successor == nullptr) {
    __ b(slow_path->GetEntryLabel(), EQ);
    __ Bind(slow_path->GetReturnLabel());
  } else {
    __ b(codegen_->GetLabelOf(successor), NE);
    __ b(slow_path->GetEntryLabel());
  }
}

ArmAssembler* ParallelMoveResolverARM::GetAssembler() const {
  return codegen_->GetAssembler();
}

void ParallelMoveResolverARM::EmitMove(size_t index) {
  MoveOperands* move = moves_.Get(index);
  Location source = move->GetSource();
  Location destination = move->GetDestination();

  if (source.IsRegister()) {
    if (destination.IsRegister()) {
      __ Mov(destination.As<Register>(), source.As<Register>());
    } else {
      DCHECK(destination.IsStackSlot());
      __ StoreToOffset(kStoreWord, source.As<Register>(),
                       SP, destination.GetStackIndex());
    }
  } else if (source.IsStackSlot()) {
    if (destination.IsRegister()) {
      __ LoadFromOffset(kLoadWord, destination.As<Register>(),
                        SP, source.GetStackIndex());
    } else {
      DCHECK(destination.IsStackSlot());
      __ LoadFromOffset(kLoadWord, IP, SP, source.GetStackIndex());
      __ StoreToOffset(kStoreWord, IP, SP, destination.GetStackIndex());
    }
  } else {
    DCHECK(source.IsConstant());
    DCHECK(source.GetConstant()->IsIntConstant());
    int32_t value = source.GetConstant()->AsIntConstant()->GetValue();
    if (destination.IsRegister()) {
      __ LoadImmediate(destination.As<Register>(), value);
    } else {
      DCHECK(destination.IsStackSlot());
      __ LoadImmediate(IP, value);
      __ StoreToOffset(kStoreWord, IP, SP, destination.GetStackIndex());
    }
  }
}

void ParallelMoveResolverARM::Exchange(Register reg, int mem) {
  __ Mov(IP, reg);
  __ LoadFromOffset(kLoadWord, reg, SP, mem);
  __ StoreToOffset(kStoreWord, IP, SP, mem);
}

void ParallelMoveResolverARM::Exchange(int mem1, int mem2) {
  ScratchRegisterScope ensure_scratch(this, IP, R0, codegen_->GetNumberOfCoreRegisters());
  int stack_offset = ensure_scratch.IsSpilled() ? kArmWordSize : 0;
  __ LoadFromOffset(kLoadWord, static_cast<Register>(ensure_scratch.GetRegister()),
                    SP, mem1 + stack_offset);
  __ LoadFromOffset(kLoadWord, IP, SP, mem2 + stack_offset);
  __ StoreToOffset(kStoreWord, static_cast<Register>(ensure_scratch.GetRegister()),
                   SP, mem2 + stack_offset);
  __ StoreToOffset(kStoreWord, IP, SP, mem1 + stack_offset);
}

void ParallelMoveResolverARM::EmitSwap(size_t index) {
  MoveOperands* move = moves_.Get(index);
  Location source = move->GetSource();
  Location destination = move->GetDestination();

  if (source.IsRegister() && destination.IsRegister()) {
    DCHECK_NE(source.As<Register>(), IP);
    DCHECK_NE(destination.As<Register>(), IP);
    __ Mov(IP, source.As<Register>());
    __ Mov(source.As<Register>(), destination.As<Register>());
    __ Mov(destination.As<Register>(), IP);
  } else if (source.IsRegister() && destination.IsStackSlot()) {
    Exchange(source.As<Register>(), destination.GetStackIndex());
  } else if (source.IsStackSlot() && destination.IsRegister()) {
    Exchange(destination.As<Register>(), source.GetStackIndex());
  } else if (source.IsStackSlot() && destination.IsStackSlot()) {
    Exchange(source.GetStackIndex(), destination.GetStackIndex());
  } else {
    LOG(FATAL) << "Unimplemented";
  }
}

void ParallelMoveResolverARM::SpillScratch(int reg) {
  __ Push(static_cast<Register>(reg));
}

void ParallelMoveResolverARM::RestoreScratch(int reg) {
  __ Pop(static_cast<Register>(reg));
}

}  // namespace arm
}  // namespace art