compiler/optimizing/code_generator_arm64.h - platform/art - Gitiles

 /*
  * 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.
  */

 #ifndef ART_COMPILER_OPTIMIZING_CODE_GENERATOR_ARM64_H_
 #define ART_COMPILER_OPTIMIZING_CODE_GENERATOR_ARM64_H_

 #include "code_generator.h"
 #include "dex/compiler_enums.h"
 #include "driver/compiler_options.h"
 #include "nodes.h"
 #include "parallel_move_resolver.h"
 #include "utils/arm64/assembler_arm64.h"
 #include "a64/disasm-a64.h"
 #include "a64/macro-assembler-a64.h"
 #include "arch/arm64/quick_method_frame_info_arm64.h"

 namespace art {
 namespace arm64 {

 class CodeGeneratorARM64;

 // Use a local definition to prevent copying mistakes.
 static constexpr size_t kArm64WordSize = kArm64PointerSize;

 static const vixl::Register kParameterCoreRegisters[] = {
   vixl::x1, vixl::x2, vixl::x3, vixl::x4, vixl::x5, vixl::x6, vixl::x7
 };
 static constexpr size_t kParameterCoreRegistersLength = arraysize(kParameterCoreRegisters);
 static const vixl::FPRegister kParameterFPRegisters[] = {
   vixl::d0, vixl::d1, vixl::d2, vixl::d3, vixl::d4, vixl::d5, vixl::d6, vixl::d7
 };
 static constexpr size_t kParameterFPRegistersLength = arraysize(kParameterFPRegisters);

 const vixl::Register tr = vixl::x18;                        // Thread Register
 static const vixl::Register kArtMethodRegister = vixl::w0;  // Method register on invoke.
 const vixl::Register kQuickSuspendRegister = vixl::x19;

 const vixl::CPURegList vixl_reserved_core_registers(vixl::ip0, vixl::ip1);
 const vixl::CPURegList vixl_reserved_fp_registers(vixl::d31);

 // TODO: When the runtime does not use kQuickSuspendRegister as a suspend
 // counter remove it from the reserved registers list.
 const vixl::CPURegList runtime_reserved_core_registers(tr, kQuickSuspendRegister, vixl::lr);

 // Callee-saved registers defined by AAPCS64.
 const vixl::CPURegList callee_saved_core_registers(vixl::CPURegister::kRegister,
                                                    vixl::kXRegSize,
                                                    vixl::x19.code(),
                                                    vixl::x30.code());
 const vixl::CPURegList callee_saved_fp_registers(vixl::CPURegister::kFPRegister,
                                                  vixl::kDRegSize,
                                                  vixl::d8.code(),
                                                  vixl::d15.code());
 Location ARM64ReturnLocation(Primitive::Type return_type);

 class SlowPathCodeARM64 : public SlowPathCode {
  public:
   SlowPathCodeARM64() : entry_label_(), exit_label_() {}

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

  private:
   vixl::Label entry_label_;
   vixl::Label exit_label_;

   DISALLOW_COPY_AND_ASSIGN(SlowPathCodeARM64);
 };

 class InvokeDexCallingConvention : public CallingConvention<vixl::Register, vixl::FPRegister> {
  public:
   InvokeDexCallingConvention()
       : CallingConvention(kParameterCoreRegisters,
                           kParameterCoreRegistersLength,
                           kParameterFPRegisters,
                           kParameterFPRegistersLength) {}

   Location GetReturnLocation(Primitive::Type return_type) {
     return ARM64ReturnLocation(return_type);
   }


  private:
   DISALLOW_COPY_AND_ASSIGN(InvokeDexCallingConvention);
 };

 class InvokeDexCallingConventionVisitor {
  public:
   InvokeDexCallingConventionVisitor() : gp_index_(0), fp_index_(0), stack_index_(0) {}

   Location GetNextLocation(Primitive::Type type);
   Location GetReturnLocation(Primitive::Type return_type) {
     return calling_convention.GetReturnLocation(return_type);
   }

  private:
   InvokeDexCallingConvention calling_convention;
   // The current index for core registers.
   uint32_t gp_index_;
   // The current index for floating-point registers.
   uint32_t fp_index_;
   // The current stack index.
   uint32_t stack_index_;

   DISALLOW_COPY_AND_ASSIGN(InvokeDexCallingConventionVisitor);
 };

 class InstructionCodeGeneratorARM64 : public HGraphVisitor {
  public:
   InstructionCodeGeneratorARM64(HGraph* graph, CodeGeneratorARM64* codegen);

 #define DECLARE_VISIT_INSTRUCTION(name, super) \
   void Visit##name(H##name* instr) OVERRIDE;
   FOR_EACH_CONCRETE_INSTRUCTION(DECLARE_VISIT_INSTRUCTION)
 #undef DECLARE_VISIT_INSTRUCTION

   void LoadCurrentMethod(XRegister reg);

   Arm64Assembler* GetAssembler() const { return assembler_; }
   vixl::MacroAssembler* GetVIXLAssembler() { return GetAssembler()->vixl_masm_; }

  private:
   void GenerateClassInitializationCheck(SlowPathCodeARM64* slow_path, vixl::Register class_reg);
   void GenerateMemoryBarrier(MemBarrierKind kind);
   void GenerateSuspendCheck(HSuspendCheck* instruction, HBasicBlock* successor);
   void HandleBinaryOp(HBinaryOperation* instr);
   void HandleShift(HBinaryOperation* instr);
   void GenerateImplicitNullCheck(HNullCheck* instruction);
   void GenerateExplicitNullCheck(HNullCheck* instruction);

   Arm64Assembler* const assembler_;
   CodeGeneratorARM64* const codegen_;

   DISALLOW_COPY_AND_ASSIGN(InstructionCodeGeneratorARM64);
 };

 class LocationsBuilderARM64 : public HGraphVisitor {
  public:
   explicit LocationsBuilderARM64(HGraph* graph, CodeGeneratorARM64* codegen)
       : HGraphVisitor(graph), codegen_(codegen) {}

 #define DECLARE_VISIT_INSTRUCTION(name, super) \
   void Visit##name(H##name* instr) OVERRIDE;
   FOR_EACH_CONCRETE_INSTRUCTION(DECLARE_VISIT_INSTRUCTION)
 #undef DECLARE_VISIT_INSTRUCTION

  private:
   void HandleBinaryOp(HBinaryOperation* instr);
   void HandleShift(HBinaryOperation* instr);
   void HandleInvoke(HInvoke* instr);

   CodeGeneratorARM64* const codegen_;
   InvokeDexCallingConventionVisitor parameter_visitor_;

   DISALLOW_COPY_AND_ASSIGN(LocationsBuilderARM64);
 };

 class ParallelMoveResolverARM64 : public ParallelMoveResolver {
  public:
   ParallelMoveResolverARM64(ArenaAllocator* allocator, CodeGeneratorARM64* codegen)
       : ParallelMoveResolver(allocator), codegen_(codegen) {}

   void EmitMove(size_t index) OVERRIDE;
   void EmitSwap(size_t index) OVERRIDE;
   void RestoreScratch(int reg) OVERRIDE;
   void SpillScratch(int reg) OVERRIDE;

  private:
   Arm64Assembler* GetAssembler() const;
   vixl::MacroAssembler* GetVIXLAssembler() const {
     return GetAssembler()->vixl_masm_;
   }

   CodeGeneratorARM64* const codegen_;

   DISALLOW_COPY_AND_ASSIGN(ParallelMoveResolverARM64);
 };

 class CodeGeneratorARM64 : public CodeGenerator {
  public:
   CodeGeneratorARM64(HGraph* graph,
                      const Arm64InstructionSetFeatures& isa_features,
                      const CompilerOptions& compiler_options);
   virtual ~CodeGeneratorARM64() {}

   void GenerateFrameEntry() OVERRIDE;
   void GenerateFrameExit() OVERRIDE;

   vixl::CPURegList GetFramePreservedCoreRegisters() const {
     return vixl::CPURegList(vixl::CPURegister::kRegister, vixl::kXRegSize,
                             core_spill_mask_);
   }

   vixl::CPURegList GetFramePreservedFPRegisters() const {
     return vixl::CPURegList(vixl::CPURegister::kFPRegister, vixl::kDRegSize,
                             fpu_spill_mask_);
   }

   void Bind(HBasicBlock* block) OVERRIDE;

   vixl::Label* GetLabelOf(HBasicBlock* block) const {
     return CommonGetLabelOf<vixl::Label>(block_labels_, block);
   }

   void Move(HInstruction* instruction, Location location, HInstruction* move_for) OVERRIDE;

   size_t GetWordSize() const OVERRIDE {
     return kArm64WordSize;
   }

   size_t GetFloatingPointSpillSlotSize() const OVERRIDE {
     // Allocated in D registers, which are word sized.
     return kArm64WordSize;
   }

   uintptr_t GetAddressOf(HBasicBlock* block) const OVERRIDE {
     vixl::Label* block_entry_label = GetLabelOf(block);
     DCHECK(block_entry_label->IsBound());
     return block_entry_label->location();
   }

   HGraphVisitor* GetLocationBuilder() OVERRIDE { return &location_builder_; }
   HGraphVisitor* GetInstructionVisitor() OVERRIDE { return &instruction_visitor_; }
   Arm64Assembler* GetAssembler() OVERRIDE { return &assembler_; }
   vixl::MacroAssembler* GetVIXLAssembler() { return GetAssembler()->vixl_masm_; }

   // Emit a write barrier.
   void MarkGCCard(vixl::Register object, vixl::Register value);

   // Register allocation.

   void SetupBlockedRegisters(bool is_baseline) const OVERRIDE;
   // AllocateFreeRegister() is only used when allocating registers locally
   // during CompileBaseline().
   Location AllocateFreeRegister(Primitive::Type type) const OVERRIDE;

   Location GetStackLocation(HLoadLocal* load) const OVERRIDE;

   size_t SaveCoreRegister(size_t stack_index, uint32_t reg_id);
   size_t RestoreCoreRegister(size_t stack_index, uint32_t reg_id);
   size_t SaveFloatingPointRegister(size_t stack_index, uint32_t reg_id);
   size_t RestoreFloatingPointRegister(size_t stack_index, uint32_t reg_id);

   // The number of registers that can be allocated. The register allocator may
   // decide to reserve and not use a few of them.
   // We do not consider registers sp, xzr, wzr. They are either not allocatable
   // (xzr, wzr), or make for poor allocatable registers (sp alignment
   // requirements, etc.). This also facilitates our task as all other registers
   // can easily be mapped via to or from their type and index or code.
   static const int kNumberOfAllocatableRegisters = vixl::kNumberOfRegisters - 1;
   static const int kNumberOfAllocatableFPRegisters = vixl::kNumberOfFPRegisters;
   static constexpr int kNumberOfAllocatableRegisterPairs = 0;

   void DumpCoreRegister(std::ostream& stream, int reg) const OVERRIDE;
   void DumpFloatingPointRegister(std::ostream& stream, int reg) const OVERRIDE;

   InstructionSet GetInstructionSet() const OVERRIDE {
     return InstructionSet::kArm64;
   }

   const Arm64InstructionSetFeatures& GetInstructionSetFeatures() const {
     return isa_features_;
   }

   void Initialize() OVERRIDE {
     HGraph* graph = GetGraph();
     int length = graph->GetBlocks().Size();
     block_labels_ = graph->GetArena()->AllocArray<vixl::Label>(length);
     for (int i = 0; i < length; ++i) {
       new(block_labels_ + i) vixl::Label();
     }
   }

   void Finalize(CodeAllocator* allocator) OVERRIDE;

   // Code generation helpers.
   void MoveConstant(vixl::CPURegister destination, HConstant* constant);
   // The type is optional. When specified it must be coherent with the
   // locations, and is used for optimisation and debugging.
   void MoveLocation(Location destination, Location source,
                     Primitive::Type type = Primitive::kPrimVoid);
   void SwapLocations(Location loc_1, Location loc_2);
   void Load(Primitive::Type type, vixl::CPURegister dst, const vixl::MemOperand& src);
   void Store(Primitive::Type type, vixl::CPURegister rt, const vixl::MemOperand& dst);
   void LoadCurrentMethod(vixl::Register current_method);
   void LoadAcquire(HInstruction* instruction, vixl::CPURegister dst, const vixl::MemOperand& src);
   void StoreRelease(Primitive::Type type, vixl::CPURegister rt, const vixl::MemOperand& dst);

   // Generate code to invoke a runtime entry point.
   void InvokeRuntime(int32_t offset,
                      HInstruction* instruction,
                      uint32_t dex_pc,
                      SlowPathCode* slow_path);

   ParallelMoveResolverARM64* GetMoveResolver() { return &move_resolver_; }

   bool NeedsTwoRegisters(Primitive::Type type ATTRIBUTE_UNUSED) const OVERRIDE {
     return false;
   }

   void GenerateStaticOrDirectCall(HInvokeStaticOrDirect* invoke, vixl::Register temp);

  private:
   // Labels for each block that will be compiled.
   vixl::Label* block_labels_;
   vixl::Label frame_entry_label_;

   LocationsBuilderARM64 location_builder_;
   InstructionCodeGeneratorARM64 instruction_visitor_;
   ParallelMoveResolverARM64 move_resolver_;
   Arm64Assembler assembler_;
   const Arm64InstructionSetFeatures& isa_features_;

   DISALLOW_COPY_AND_ASSIGN(CodeGeneratorARM64);
 };

 inline Arm64Assembler* ParallelMoveResolverARM64::GetAssembler() const {
   return codegen_->GetAssembler();
 }

 }  // namespace arm64
 }  // namespace art

 #endif  // ART_COMPILER_OPTIMIZING_CODE_GENERATOR_ARM64_H_
	/*
	* 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.
	*/

	#ifndef ART_COMPILER_OPTIMIZING_CODE_GENERATOR_ARM64_H_
	#define ART_COMPILER_OPTIMIZING_CODE_GENERATOR_ARM64_H_

	#include "code_generator.h"
	#include "dex/compiler_enums.h"
	#include "driver/compiler_options.h"
	#include "nodes.h"
	#include "parallel_move_resolver.h"
	#include "utils/arm64/assembler_arm64.h"
	#include "a64/disasm-a64.h"
	#include "a64/macro-assembler-a64.h"
	#include "arch/arm64/quick_method_frame_info_arm64.h"

	namespace art {
	namespace arm64 {

	class CodeGeneratorARM64;

	// Use a local definition to prevent copying mistakes.
	static constexpr size_t kArm64WordSize = kArm64PointerSize;

	static const vixl::Register kParameterCoreRegisters[] = {
	vixl::x1, vixl::x2, vixl::x3, vixl::x4, vixl::x5, vixl::x6, vixl::x7
	};
	static constexpr size_t kParameterCoreRegistersLength = arraysize(kParameterCoreRegisters);
	static const vixl::FPRegister kParameterFPRegisters[] = {
	vixl::d0, vixl::d1, vixl::d2, vixl::d3, vixl::d4, vixl::d5, vixl::d6, vixl::d7
	};
	static constexpr size_t kParameterFPRegistersLength = arraysize(kParameterFPRegisters);

	const vixl::Register tr = vixl::x18; // Thread Register
	static const vixl::Register kArtMethodRegister = vixl::w0; // Method register on invoke.
	const vixl::Register kQuickSuspendRegister = vixl::x19;

	const vixl::CPURegList vixl_reserved_core_registers(vixl::ip0, vixl::ip1);
	const vixl::CPURegList vixl_reserved_fp_registers(vixl::d31);

	// TODO: When the runtime does not use kQuickSuspendRegister as a suspend
	// counter remove it from the reserved registers list.
	const vixl::CPURegList runtime_reserved_core_registers(tr, kQuickSuspendRegister, vixl::lr);

	// Callee-saved registers defined by AAPCS64.
	const vixl::CPURegList callee_saved_core_registers(vixl::CPURegister::kRegister,
	vixl::kXRegSize,
	vixl::x19.code(),
	vixl::x30.code());
	const vixl::CPURegList callee_saved_fp_registers(vixl::CPURegister::kFPRegister,
	vixl::kDRegSize,
	vixl::d8.code(),
	vixl::d15.code());
	Location ARM64ReturnLocation(Primitive::Type return_type);

	class SlowPathCodeARM64 : public SlowPathCode {
	public:
	SlowPathCodeARM64() : entry_label_(), exit_label_() {}

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

	private:
	vixl::Label entry_label_;
	vixl::Label exit_label_;

	DISALLOW_COPY_AND_ASSIGN(SlowPathCodeARM64);
	};

	class InvokeDexCallingConvention : public CallingConvention<vixl::Register, vixl::FPRegister> {
	public:
	InvokeDexCallingConvention()
	: CallingConvention(kParameterCoreRegisters,
	kParameterCoreRegistersLength,
	kParameterFPRegisters,
	kParameterFPRegistersLength) {}

	Location GetReturnLocation(Primitive::Type return_type) {
	return ARM64ReturnLocation(return_type);
	}


	private:
	DISALLOW_COPY_AND_ASSIGN(InvokeDexCallingConvention);
	};

	class InvokeDexCallingConventionVisitor {
	public:
	InvokeDexCallingConventionVisitor() : gp_index_(0), fp_index_(0), stack_index_(0) {}

	Location GetNextLocation(Primitive::Type type);
	Location GetReturnLocation(Primitive::Type return_type) {
	return calling_convention.GetReturnLocation(return_type);
	}

	private:
	InvokeDexCallingConvention calling_convention;
	// The current index for core registers.
	uint32_t gp_index_;
	// The current index for floating-point registers.
	uint32_t fp_index_;
	// The current stack index.
	uint32_t stack_index_;

	DISALLOW_COPY_AND_ASSIGN(InvokeDexCallingConventionVisitor);
	};

	class InstructionCodeGeneratorARM64 : public HGraphVisitor {
	public:
	InstructionCodeGeneratorARM64(HGraph* graph, CodeGeneratorARM64* codegen);

	#define DECLARE_VISIT_INSTRUCTION(name, super) \
	void Visit##name(H##name* instr) OVERRIDE;
	FOR_EACH_CONCRETE_INSTRUCTION(DECLARE_VISIT_INSTRUCTION)
	#undef DECLARE_VISIT_INSTRUCTION

	void LoadCurrentMethod(XRegister reg);

	Arm64Assembler* GetAssembler() const { return assembler_; }
	vixl::MacroAssembler* GetVIXLAssembler() { return GetAssembler()->vixl_masm_; }

	private:
	void GenerateClassInitializationCheck(SlowPathCodeARM64* slow_path, vixl::Register class_reg);
	void GenerateMemoryBarrier(MemBarrierKind kind);
	void GenerateSuspendCheck(HSuspendCheck* instruction, HBasicBlock* successor);
	void HandleBinaryOp(HBinaryOperation* instr);
	void HandleShift(HBinaryOperation* instr);
	void GenerateImplicitNullCheck(HNullCheck* instruction);
	void GenerateExplicitNullCheck(HNullCheck* instruction);

	Arm64Assembler* const assembler_;
	CodeGeneratorARM64* const codegen_;

	DISALLOW_COPY_AND_ASSIGN(InstructionCodeGeneratorARM64);
	};

	class LocationsBuilderARM64 : public HGraphVisitor {
	public:
	explicit LocationsBuilderARM64(HGraph* graph, CodeGeneratorARM64* codegen)
	: HGraphVisitor(graph), codegen_(codegen) {}

	#define DECLARE_VISIT_INSTRUCTION(name, super) \
	void Visit##name(H##name* instr) OVERRIDE;
	FOR_EACH_CONCRETE_INSTRUCTION(DECLARE_VISIT_INSTRUCTION)
	#undef DECLARE_VISIT_INSTRUCTION

	private:
	void HandleBinaryOp(HBinaryOperation* instr);
	void HandleShift(HBinaryOperation* instr);
	void HandleInvoke(HInvoke* instr);

	CodeGeneratorARM64* const codegen_;
	InvokeDexCallingConventionVisitor parameter_visitor_;

	DISALLOW_COPY_AND_ASSIGN(LocationsBuilderARM64);
	};

	class ParallelMoveResolverARM64 : public ParallelMoveResolver {
	public:
	ParallelMoveResolverARM64(ArenaAllocator* allocator, CodeGeneratorARM64* codegen)
	: ParallelMoveResolver(allocator), codegen_(codegen) {}

	void EmitMove(size_t index) OVERRIDE;
	void EmitSwap(size_t index) OVERRIDE;
	void RestoreScratch(int reg) OVERRIDE;
	void SpillScratch(int reg) OVERRIDE;

	private:
	Arm64Assembler* GetAssembler() const;
	vixl::MacroAssembler* GetVIXLAssembler() const {
	return GetAssembler()->vixl_masm_;
	}

	CodeGeneratorARM64* const codegen_;

	DISALLOW_COPY_AND_ASSIGN(ParallelMoveResolverARM64);
	};

	class CodeGeneratorARM64 : public CodeGenerator {
	public:
	CodeGeneratorARM64(HGraph* graph,
	const Arm64InstructionSetFeatures& isa_features,
	const CompilerOptions& compiler_options);
	virtual ~CodeGeneratorARM64() {}

	void GenerateFrameEntry() OVERRIDE;
	void GenerateFrameExit() OVERRIDE;

	vixl::CPURegList GetFramePreservedCoreRegisters() const {
	return vixl::CPURegList(vixl::CPURegister::kRegister, vixl::kXRegSize,
	core_spill_mask_);
	}

	vixl::CPURegList GetFramePreservedFPRegisters() const {
	return vixl::CPURegList(vixl::CPURegister::kFPRegister, vixl::kDRegSize,
	fpu_spill_mask_);
	}

	void Bind(HBasicBlock* block) OVERRIDE;

	vixl::Label* GetLabelOf(HBasicBlock* block) const {
	return CommonGetLabelOf<vixl::Label>(block_labels_, block);
	}

	void Move(HInstruction* instruction, Location location, HInstruction* move_for) OVERRIDE;

	size_t GetWordSize() const OVERRIDE {
	return kArm64WordSize;
	}

	size_t GetFloatingPointSpillSlotSize() const OVERRIDE {
	// Allocated in D registers, which are word sized.
	return kArm64WordSize;
	}

	uintptr_t GetAddressOf(HBasicBlock* block) const OVERRIDE {
	vixl::Label* block_entry_label = GetLabelOf(block);
	DCHECK(block_entry_label->IsBound());
	return block_entry_label->location();
	}

	HGraphVisitor* GetLocationBuilder() OVERRIDE { return &location_builder_; }
	HGraphVisitor* GetInstructionVisitor() OVERRIDE { return &instruction_visitor_; }
	Arm64Assembler* GetAssembler() OVERRIDE { return &assembler_; }
	vixl::MacroAssembler* GetVIXLAssembler() { return GetAssembler()->vixl_masm_; }

	// Emit a write barrier.
	void MarkGCCard(vixl::Register object, vixl::Register value);

	// Register allocation.

	void SetupBlockedRegisters(bool is_baseline) const OVERRIDE;
	// AllocateFreeRegister() is only used when allocating registers locally
	// during CompileBaseline().
	Location AllocateFreeRegister(Primitive::Type type) const OVERRIDE;

	Location GetStackLocation(HLoadLocal* load) const OVERRIDE;

	size_t SaveCoreRegister(size_t stack_index, uint32_t reg_id);
	size_t RestoreCoreRegister(size_t stack_index, uint32_t reg_id);
	size_t SaveFloatingPointRegister(size_t stack_index, uint32_t reg_id);
	size_t RestoreFloatingPointRegister(size_t stack_index, uint32_t reg_id);

	// The number of registers that can be allocated. The register allocator may
	// decide to reserve and not use a few of them.
	// We do not consider registers sp, xzr, wzr. They are either not allocatable
	// (xzr, wzr), or make for poor allocatable registers (sp alignment
	// requirements, etc.). This also facilitates our task as all other registers
	// can easily be mapped via to or from their type and index or code.
	static const int kNumberOfAllocatableRegisters = vixl::kNumberOfRegisters - 1;
	static const int kNumberOfAllocatableFPRegisters = vixl::kNumberOfFPRegisters;
	static constexpr int kNumberOfAllocatableRegisterPairs = 0;

	void DumpCoreRegister(std::ostream& stream, int reg) const OVERRIDE;
	void DumpFloatingPointRegister(std::ostream& stream, int reg) const OVERRIDE;

	InstructionSet GetInstructionSet() const OVERRIDE {
	return InstructionSet::kArm64;
	}

	const Arm64InstructionSetFeatures& GetInstructionSetFeatures() const {
	return isa_features_;
	}

	void Initialize() OVERRIDE {
	HGraph* graph = GetGraph();
	int length = graph->GetBlocks().Size();
	block_labels_ = graph->GetArena()->AllocArray<vixl::Label>(length);
	for (int i = 0; i < length; ++i) {
	new(block_labels_ + i) vixl::Label();
	}
	}

	void Finalize(CodeAllocator* allocator) OVERRIDE;

	// Code generation helpers.
	void MoveConstant(vixl::CPURegister destination, HConstant* constant);
	// The type is optional. When specified it must be coherent with the
	// locations, and is used for optimisation and debugging.
	void MoveLocation(Location destination, Location source,
	Primitive::Type type = Primitive::kPrimVoid);
	void SwapLocations(Location loc_1, Location loc_2);
	void Load(Primitive::Type type, vixl::CPURegister dst, const vixl::MemOperand& src);
	void Store(Primitive::Type type, vixl::CPURegister rt, const vixl::MemOperand& dst);
	void LoadCurrentMethod(vixl::Register current_method);
	void LoadAcquire(HInstruction* instruction, vixl::CPURegister dst, const vixl::MemOperand& src);
	void StoreRelease(Primitive::Type type, vixl::CPURegister rt, const vixl::MemOperand& dst);

	// Generate code to invoke a runtime entry point.
	void InvokeRuntime(int32_t offset,
	HInstruction* instruction,
	uint32_t dex_pc,
	SlowPathCode* slow_path);

	ParallelMoveResolverARM64* GetMoveResolver() { return &move_resolver_; }

	bool NeedsTwoRegisters(Primitive::Type type ATTRIBUTE_UNUSED) const OVERRIDE {
	return false;
	}

	void GenerateStaticOrDirectCall(HInvokeStaticOrDirect* invoke, vixl::Register temp);

	private:
	// Labels for each block that will be compiled.
	vixl::Label* block_labels_;
	vixl::Label frame_entry_label_;

	LocationsBuilderARM64 location_builder_;
	InstructionCodeGeneratorARM64 instruction_visitor_;
	ParallelMoveResolverARM64 move_resolver_;
	Arm64Assembler assembler_;
	const Arm64InstructionSetFeatures& isa_features_;

	DISALLOW_COPY_AND_ASSIGN(CodeGeneratorARM64);
	};

	inline Arm64Assembler* ParallelMoveResolverARM64::GetAssembler() const {
	return codegen_->GetAssembler();
	}

	} // namespace arm64
	} // namespace art

	#endif // ART_COMPILER_OPTIMIZING_CODE_GENERATOR_ARM64_H_