compiler/optimizing/common_arm64.h - platform/art - Git at Google

 /*
  * Copyright (C) 2015 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_COMMON_ARM64_H_
 #define ART_COMPILER_OPTIMIZING_COMMON_ARM64_H_

 #include "code_generator.h"
 #include "instruction_simplifier_shared.h"
 #include "locations.h"
 #include "nodes.h"
 #include "utils/arm64/assembler_arm64.h"

 // TODO(VIXL): Make VIXL compile with -Wshadow.
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wshadow"
 #include "aarch64/disasm-aarch64.h"
 #include "aarch64/macro-assembler-aarch64.h"
 #include "aarch64/simulator-aarch64.h"
 #pragma GCC diagnostic pop

 namespace art {

 using helpers::CanFitInShifterOperand;
 using helpers::HasShifterOperand;

 namespace arm64 {
 namespace helpers {

 // Convenience helpers to ease conversion to and from VIXL operands.
 static_assert((SP == 31) && (WSP == 31) && (XZR == 32) && (WZR == 32),
               "Unexpected values for register codes.");

 inline int VIXLRegCodeFromART(int code) {
   if (code == SP) {
     return vixl::aarch64::kSPRegInternalCode;
   }
   if (code == XZR) {
     return vixl::aarch64::kZeroRegCode;
   }
   return code;
 }

 inline int ARTRegCodeFromVIXL(int code) {
   if (code == vixl::aarch64::kSPRegInternalCode) {
     return SP;
   }
   if (code == vixl::aarch64::kZeroRegCode) {
     return XZR;
   }
   return code;
 }

 inline vixl::aarch64::Register XRegisterFrom(Location location) {
   DCHECK(location.IsRegister()) << location;
   return vixl::aarch64::Register::GetXRegFromCode(VIXLRegCodeFromART(location.reg()));
 }

 inline vixl::aarch64::Register WRegisterFrom(Location location) {
   DCHECK(location.IsRegister()) << location;
   return vixl::aarch64::Register::GetWRegFromCode(VIXLRegCodeFromART(location.reg()));
 }

 inline vixl::aarch64::Register RegisterFrom(Location location, DataType::Type type) {
   DCHECK(type != DataType::Type::kVoid && !DataType::IsFloatingPointType(type)) << type;
   return type == DataType::Type::kInt64 ? XRegisterFrom(location) : WRegisterFrom(location);
 }

 inline vixl::aarch64::Register OutputRegister(HInstruction* instr) {
   return RegisterFrom(instr->GetLocations()->Out(), instr->GetType());
 }

 inline vixl::aarch64::Register InputRegisterAt(HInstruction* instr, int input_index) {
   return RegisterFrom(instr->GetLocations()->InAt(input_index),
                       instr->InputAt(input_index)->GetType());
 }

 inline vixl::aarch64::FPRegister DRegisterFrom(Location location) {
   DCHECK(location.IsFpuRegister()) << location;
   return vixl::aarch64::FPRegister::GetDRegFromCode(location.reg());
 }

 inline vixl::aarch64::FPRegister QRegisterFrom(Location location) {
   DCHECK(location.IsFpuRegister()) << location;
   return vixl::aarch64::FPRegister::GetQRegFromCode(location.reg());
 }

 inline vixl::aarch64::FPRegister VRegisterFrom(Location location) {
   DCHECK(location.IsFpuRegister()) << location;
   return vixl::aarch64::FPRegister::GetVRegFromCode(location.reg());
 }

 inline vixl::aarch64::FPRegister SRegisterFrom(Location location) {
   DCHECK(location.IsFpuRegister()) << location;
   return vixl::aarch64::FPRegister::GetSRegFromCode(location.reg());
 }

 inline vixl::aarch64::FPRegister FPRegisterFrom(Location location, DataType::Type type) {
   DCHECK(DataType::IsFloatingPointType(type)) << type;
   return type == DataType::Type::kFloat64 ? DRegisterFrom(location) : SRegisterFrom(location);
 }

 inline vixl::aarch64::FPRegister OutputFPRegister(HInstruction* instr) {
   return FPRegisterFrom(instr->GetLocations()->Out(), instr->GetType());
 }

 inline vixl::aarch64::FPRegister InputFPRegisterAt(HInstruction* instr, int input_index) {
   return FPRegisterFrom(instr->GetLocations()->InAt(input_index),
                         instr->InputAt(input_index)->GetType());
 }

 inline vixl::aarch64::CPURegister CPURegisterFrom(Location location, DataType::Type type) {
   return DataType::IsFloatingPointType(type)
       ? vixl::aarch64::CPURegister(FPRegisterFrom(location, type))
       : vixl::aarch64::CPURegister(RegisterFrom(location, type));
 }

 inline vixl::aarch64::CPURegister OutputCPURegister(HInstruction* instr) {
   return DataType::IsFloatingPointType(instr->GetType())
       ? static_cast<vixl::aarch64::CPURegister>(OutputFPRegister(instr))
       : static_cast<vixl::aarch64::CPURegister>(OutputRegister(instr));
 }

 inline vixl::aarch64::CPURegister InputCPURegisterAt(HInstruction* instr, int index) {
   return DataType::IsFloatingPointType(instr->InputAt(index)->GetType())
       ? static_cast<vixl::aarch64::CPURegister>(InputFPRegisterAt(instr, index))
       : static_cast<vixl::aarch64::CPURegister>(InputRegisterAt(instr, index));
 }

 inline vixl::aarch64::CPURegister InputCPURegisterOrZeroRegAt(HInstruction* instr,
                                                                      int index) {
   HInstruction* input = instr->InputAt(index);
   DataType::Type input_type = input->GetType();
   if (input->IsConstant() && input->AsConstant()->IsZeroBitPattern()) {
     return (DataType::Size(input_type) >= vixl::aarch64::kXRegSizeInBytes)
         ? vixl::aarch64::Register(vixl::aarch64::xzr)
         : vixl::aarch64::Register(vixl::aarch64::wzr);
   }
   return InputCPURegisterAt(instr, index);
 }

 inline int64_t Int64FromLocation(Location location) {
   return Int64FromConstant(location.GetConstant());
 }

 inline vixl::aarch64::Operand OperandFrom(Location location, DataType::Type type) {
   if (location.IsRegister()) {
     return vixl::aarch64::Operand(RegisterFrom(location, type));
   } else {
     return vixl::aarch64::Operand(Int64FromLocation(location));
   }
 }

 inline vixl::aarch64::Operand InputOperandAt(HInstruction* instr, int input_index) {
   return OperandFrom(instr->GetLocations()->InAt(input_index),
                      instr->InputAt(input_index)->GetType());
 }

 inline vixl::aarch64::MemOperand StackOperandFrom(Location location) {
   return vixl::aarch64::MemOperand(vixl::aarch64::sp, location.GetStackIndex());
 }

 inline vixl::aarch64::MemOperand HeapOperand(const vixl::aarch64::Register& base,
                                                     size_t offset = 0) {
   // A heap reference must be 32bit, so fit in a W register.
   DCHECK(base.IsW());
   return vixl::aarch64::MemOperand(base.X(), offset);
 }

 inline vixl::aarch64::MemOperand HeapOperand(const vixl::aarch64::Register& base,
                                                     const vixl::aarch64::Register& regoffset,
                                                     vixl::aarch64::Shift shift = vixl::aarch64::LSL,
                                                     unsigned shift_amount = 0) {
   // A heap reference must be 32bit, so fit in a W register.
   DCHECK(base.IsW());
   return vixl::aarch64::MemOperand(base.X(), regoffset, shift, shift_amount);
 }

 inline vixl::aarch64::MemOperand HeapOperand(const vixl::aarch64::Register& base,
                                                     Offset offset) {
   return HeapOperand(base, offset.SizeValue());
 }

 inline vixl::aarch64::MemOperand HeapOperandFrom(Location location, Offset offset) {
   return HeapOperand(RegisterFrom(location, DataType::Type::kReference), offset);
 }

 inline Location LocationFrom(const vixl::aarch64::Register& reg) {
   return Location::RegisterLocation(ARTRegCodeFromVIXL(reg.GetCode()));
 }

 inline Location LocationFrom(const vixl::aarch64::FPRegister& fpreg) {
   return Location::FpuRegisterLocation(fpreg.GetCode());
 }

 inline vixl::aarch64::Operand OperandFromMemOperand(
     const vixl::aarch64::MemOperand& mem_op) {
   if (mem_op.IsImmediateOffset()) {
     return vixl::aarch64::Operand(mem_op.GetOffset());
   } else {
     DCHECK(mem_op.IsRegisterOffset());
     if (mem_op.GetExtend() != vixl::aarch64::NO_EXTEND) {
       return vixl::aarch64::Operand(mem_op.GetRegisterOffset(),
                                     mem_op.GetExtend(),
                                     mem_op.GetShiftAmount());
     } else if (mem_op.GetShift() != vixl::aarch64::NO_SHIFT) {
       return vixl::aarch64::Operand(mem_op.GetRegisterOffset(),
                                     mem_op.GetShift(),
                                     mem_op.GetShiftAmount());
     } else {
       LOG(FATAL) << "Should not reach here";
       UNREACHABLE();
     }
   }
 }

 inline bool AddSubCanEncodeAsImmediate(int64_t value) {
   // If `value` does not fit but `-value` does, VIXL will automatically use
   // the 'opposite' instruction.
   return vixl::aarch64::Assembler::IsImmAddSub(value)
       || vixl::aarch64::Assembler::IsImmAddSub(-value);
 }

 inline bool Arm64CanEncodeConstantAsImmediate(HConstant* constant, HInstruction* instr) {
   int64_t value = CodeGenerator::GetInt64ValueOf(constant);

   // TODO: Improve this when IsSIMDConstantEncodable method is implemented in VIXL.
   if (instr->IsVecReplicateScalar()) {
     if (constant->IsLongConstant()) {
       return false;
     } else if (constant->IsFloatConstant()) {
       return vixl::aarch64::Assembler::IsImmFP32(constant->AsFloatConstant()->GetValue());
     } else if (constant->IsDoubleConstant()) {
       return vixl::aarch64::Assembler::IsImmFP64(constant->AsDoubleConstant()->GetValue());
     }
     return IsUint<8>(value);
   }

   // Code generation for Min/Max:
   //    Cmp left_op, right_op
   //    Csel dst, left_op, right_op, cond
   if (instr->IsMin() || instr->IsMax()) {
     if (constant->GetUses().HasExactlyOneElement()) {
       // If value can be encoded as immediate for the Cmp, then let VIXL handle
       // the constant generation for the Csel.
       return AddSubCanEncodeAsImmediate(value);
     }
     // These values are encodable as immediates for Cmp and VIXL will use csinc and csinv
     // with the zr register as right_op, hence no constant generation is required.
     return constant->IsZeroBitPattern() || constant->IsOne() || constant->IsMinusOne();
   }

   // For single uses we let VIXL handle the constant generation since it will
   // use registers that are not managed by the register allocator (wip0, wip1).
   if (constant->GetUses().HasExactlyOneElement()) {
     return true;
   }

   // Our code generator ensures shift distances are within an encodable range.
   if (instr->IsRor()) {
     return true;
   }

   if (instr->IsAnd() || instr->IsOr() || instr->IsXor()) {
     // Uses logical operations.
     return vixl::aarch64::Assembler::IsImmLogical(value, vixl::aarch64::kXRegSize);
   } else if (instr->IsNeg()) {
     // Uses mov -immediate.
     return vixl::aarch64::Assembler::IsImmMovn(value, vixl::aarch64::kXRegSize);
   } else {
     DCHECK(instr->IsAdd() ||
            instr->IsIntermediateAddress() ||
            instr->IsBoundsCheck() ||
            instr->IsCompare() ||
            instr->IsCondition() ||
            instr->IsSub())
         << instr->DebugName();
     // Uses aliases of ADD/SUB instructions.
     return AddSubCanEncodeAsImmediate(value);
   }
 }

 inline Location ARM64EncodableConstantOrRegister(HInstruction* constant,
                                                         HInstruction* instr) {
   if (constant->IsConstant()
       && Arm64CanEncodeConstantAsImmediate(constant->AsConstant(), instr)) {
     return Location::ConstantLocation(constant->AsConstant());
   }

   return Location::RequiresRegister();
 }

 // Check if registers in art register set have the same register code in vixl. If the register
 // codes are same, we can initialize vixl register list simply by the register masks. Currently,
 // only SP/WSP and ZXR/WZR codes are different between art and vixl.
 // Note: This function is only used for debug checks.
 inline bool ArtVixlRegCodeCoherentForRegSet(uint32_t art_core_registers,
                                             size_t num_core,
                                             uint32_t art_fpu_registers,
                                             size_t num_fpu) {
   // The register masks won't work if the number of register is larger than 32.
   DCHECK_GE(sizeof(art_core_registers) * 8, num_core);
   DCHECK_GE(sizeof(art_fpu_registers) * 8, num_fpu);
   for (size_t art_reg_code = 0;  art_reg_code < num_core; ++art_reg_code) {
     if (RegisterSet::Contains(art_core_registers, art_reg_code)) {
       if (art_reg_code != static_cast<size_t>(VIXLRegCodeFromART(art_reg_code))) {
         return false;
       }
     }
   }
   // There is no register code translation for float registers.
   return true;
 }

 inline vixl::aarch64::Shift ShiftFromOpKind(HDataProcWithShifterOp::OpKind op_kind) {
   switch (op_kind) {
     case HDataProcWithShifterOp::kASR: return vixl::aarch64::ASR;
     case HDataProcWithShifterOp::kLSL: return vixl::aarch64::LSL;
     case HDataProcWithShifterOp::kLSR: return vixl::aarch64::LSR;
     default:
       LOG(FATAL) << "Unexpected op kind " << op_kind;
       UNREACHABLE();
       return vixl::aarch64::NO_SHIFT;
   }
 }

 inline vixl::aarch64::Extend ExtendFromOpKind(HDataProcWithShifterOp::OpKind op_kind) {
   switch (op_kind) {
     case HDataProcWithShifterOp::kUXTB: return vixl::aarch64::UXTB;
     case HDataProcWithShifterOp::kUXTH: return vixl::aarch64::UXTH;
     case HDataProcWithShifterOp::kUXTW: return vixl::aarch64::UXTW;
     case HDataProcWithShifterOp::kSXTB: return vixl::aarch64::SXTB;
     case HDataProcWithShifterOp::kSXTH: return vixl::aarch64::SXTH;
     case HDataProcWithShifterOp::kSXTW: return vixl::aarch64::SXTW;
     default:
       LOG(FATAL) << "Unexpected op kind " << op_kind;
       UNREACHABLE();
       return vixl::aarch64::NO_EXTEND;
   }
 }

 inline bool ShifterOperandSupportsExtension(HInstruction* instruction) {
   DCHECK(HasShifterOperand(instruction, InstructionSet::kArm64));
   // Although the `neg` instruction is an alias of the `sub` instruction, `HNeg`
   // does *not* support extension. This is because the `extended register` form
   // of the `sub` instruction interprets the left register with code 31 as the
   // stack pointer and not the zero register. (So does the `immediate` form.) In
   // the other form `shifted register, the register with code 31 is interpreted
   // as the zero register.
   return instruction->IsAdd() || instruction->IsSub();
 }

 inline bool IsConstantZeroBitPattern(const HInstruction* instruction) {
   return instruction->IsConstant() && instruction->AsConstant()->IsZeroBitPattern();
 }

 }  // namespace helpers
 }  // namespace arm64
 }  // namespace art

 #endif  // ART_COMPILER_OPTIMIZING_COMMON_ARM64_H_
	/*
	* Copyright (C) 2015 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_COMMON_ARM64_H_
	#define ART_COMPILER_OPTIMIZING_COMMON_ARM64_H_

	#include "code_generator.h"
	#include "instruction_simplifier_shared.h"
	#include "locations.h"
	#include "nodes.h"
	#include "utils/arm64/assembler_arm64.h"

	// TODO(VIXL): Make VIXL compile with -Wshadow.
	#pragma GCC diagnostic push
	#pragma GCC diagnostic ignored "-Wshadow"
	#include "aarch64/disasm-aarch64.h"
	#include "aarch64/macro-assembler-aarch64.h"
	#include "aarch64/simulator-aarch64.h"
	#pragma GCC diagnostic pop

	namespace art {

	using helpers::CanFitInShifterOperand;
	using helpers::HasShifterOperand;

	namespace arm64 {
	namespace helpers {

	// Convenience helpers to ease conversion to and from VIXL operands.
	static_assert((SP == 31) && (WSP == 31) && (XZR == 32) && (WZR == 32),
	"Unexpected values for register codes.");

	inline int VIXLRegCodeFromART(int code) {
	if (code == SP) {
	return vixl::aarch64::kSPRegInternalCode;
	}
	if (code == XZR) {
	return vixl::aarch64::kZeroRegCode;
	}
	return code;
	}

	inline int ARTRegCodeFromVIXL(int code) {
	if (code == vixl::aarch64::kSPRegInternalCode) {
	return SP;
	}
	if (code == vixl::aarch64::kZeroRegCode) {
	return XZR;
	}
	return code;
	}

	inline vixl::aarch64::Register XRegisterFrom(Location location) {
	DCHECK(location.IsRegister()) << location;
	return vixl::aarch64::Register::GetXRegFromCode(VIXLRegCodeFromART(location.reg()));
	}

	inline vixl::aarch64::Register WRegisterFrom(Location location) {
	DCHECK(location.IsRegister()) << location;
	return vixl::aarch64::Register::GetWRegFromCode(VIXLRegCodeFromART(location.reg()));
	}

	inline vixl::aarch64::Register RegisterFrom(Location location, DataType::Type type) {
	DCHECK(type != DataType::Type::kVoid && !DataType::IsFloatingPointType(type)) << type;
	return type == DataType::Type::kInt64 ? XRegisterFrom(location) : WRegisterFrom(location);
	}

	inline vixl::aarch64::Register OutputRegister(HInstruction* instr) {
	return RegisterFrom(instr->GetLocations()->Out(), instr->GetType());
	}

	inline vixl::aarch64::Register InputRegisterAt(HInstruction* instr, int input_index) {
	return RegisterFrom(instr->GetLocations()->InAt(input_index),
	instr->InputAt(input_index)->GetType());
	}

	inline vixl::aarch64::FPRegister DRegisterFrom(Location location) {
	DCHECK(location.IsFpuRegister()) << location;
	return vixl::aarch64::FPRegister::GetDRegFromCode(location.reg());
	}

	inline vixl::aarch64::FPRegister QRegisterFrom(Location location) {
	DCHECK(location.IsFpuRegister()) << location;
	return vixl::aarch64::FPRegister::GetQRegFromCode(location.reg());
	}

	inline vixl::aarch64::FPRegister VRegisterFrom(Location location) {
	DCHECK(location.IsFpuRegister()) << location;
	return vixl::aarch64::FPRegister::GetVRegFromCode(location.reg());
	}

	inline vixl::aarch64::FPRegister SRegisterFrom(Location location) {
	DCHECK(location.IsFpuRegister()) << location;
	return vixl::aarch64::FPRegister::GetSRegFromCode(location.reg());
	}

	inline vixl::aarch64::FPRegister FPRegisterFrom(Location location, DataType::Type type) {
	DCHECK(DataType::IsFloatingPointType(type)) << type;
	return type == DataType::Type::kFloat64 ? DRegisterFrom(location) : SRegisterFrom(location);
	}

	inline vixl::aarch64::FPRegister OutputFPRegister(HInstruction* instr) {
	return FPRegisterFrom(instr->GetLocations()->Out(), instr->GetType());
	}

	inline vixl::aarch64::FPRegister InputFPRegisterAt(HInstruction* instr, int input_index) {
	return FPRegisterFrom(instr->GetLocations()->InAt(input_index),
	instr->InputAt(input_index)->GetType());
	}

	inline vixl::aarch64::CPURegister CPURegisterFrom(Location location, DataType::Type type) {
	return DataType::IsFloatingPointType(type)
	? vixl::aarch64::CPURegister(FPRegisterFrom(location, type))
	: vixl::aarch64::CPURegister(RegisterFrom(location, type));
	}

	inline vixl::aarch64::CPURegister OutputCPURegister(HInstruction* instr) {
	return DataType::IsFloatingPointType(instr->GetType())
	? static_cast<vixl::aarch64::CPURegister>(OutputFPRegister(instr))
	: static_cast<vixl::aarch64::CPURegister>(OutputRegister(instr));
	}

	inline vixl::aarch64::CPURegister InputCPURegisterAt(HInstruction* instr, int index) {
	return DataType::IsFloatingPointType(instr->InputAt(index)->GetType())
	? static_cast<vixl::aarch64::CPURegister>(InputFPRegisterAt(instr, index))
	: static_cast<vixl::aarch64::CPURegister>(InputRegisterAt(instr, index));
	}

	inline vixl::aarch64::CPURegister InputCPURegisterOrZeroRegAt(HInstruction* instr,
	int index) {
	HInstruction* input = instr->InputAt(index);
	DataType::Type input_type = input->GetType();
	if (input->IsConstant() && input->AsConstant()->IsZeroBitPattern()) {
	return (DataType::Size(input_type) >= vixl::aarch64::kXRegSizeInBytes)
	? vixl::aarch64::Register(vixl::aarch64::xzr)
	: vixl::aarch64::Register(vixl::aarch64::wzr);
	}
	return InputCPURegisterAt(instr, index);
	}

	inline int64_t Int64FromLocation(Location location) {
	return Int64FromConstant(location.GetConstant());
	}

	inline vixl::aarch64::Operand OperandFrom(Location location, DataType::Type type) {
	if (location.IsRegister()) {
	return vixl::aarch64::Operand(RegisterFrom(location, type));
	} else {
	return vixl::aarch64::Operand(Int64FromLocation(location));
	}
	}

	inline vixl::aarch64::Operand InputOperandAt(HInstruction* instr, int input_index) {
	return OperandFrom(instr->GetLocations()->InAt(input_index),
	instr->InputAt(input_index)->GetType());
	}

	inline vixl::aarch64::MemOperand StackOperandFrom(Location location) {
	return vixl::aarch64::MemOperand(vixl::aarch64::sp, location.GetStackIndex());
	}

	inline vixl::aarch64::MemOperand HeapOperand(const vixl::aarch64::Register& base,
	size_t offset = 0) {
	// A heap reference must be 32bit, so fit in a W register.
	DCHECK(base.IsW());
	return vixl::aarch64::MemOperand(base.X(), offset);
	}

	inline vixl::aarch64::MemOperand HeapOperand(const vixl::aarch64::Register& base,
	const vixl::aarch64::Register& regoffset,
	vixl::aarch64::Shift shift = vixl::aarch64::LSL,
	unsigned shift_amount = 0) {
	// A heap reference must be 32bit, so fit in a W register.
	DCHECK(base.IsW());
	return vixl::aarch64::MemOperand(base.X(), regoffset, shift, shift_amount);
	}

	inline vixl::aarch64::MemOperand HeapOperand(const vixl::aarch64::Register& base,
	Offset offset) {
	return HeapOperand(base, offset.SizeValue());
	}

	inline vixl::aarch64::MemOperand HeapOperandFrom(Location location, Offset offset) {
	return HeapOperand(RegisterFrom(location, DataType::Type::kReference), offset);
	}

	inline Location LocationFrom(const vixl::aarch64::Register& reg) {
	return Location::RegisterLocation(ARTRegCodeFromVIXL(reg.GetCode()));
	}

	inline Location LocationFrom(const vixl::aarch64::FPRegister& fpreg) {
	return Location::FpuRegisterLocation(fpreg.GetCode());
	}

	inline vixl::aarch64::Operand OperandFromMemOperand(
	const vixl::aarch64::MemOperand& mem_op) {
	if (mem_op.IsImmediateOffset()) {
	return vixl::aarch64::Operand(mem_op.GetOffset());
	} else {
	DCHECK(mem_op.IsRegisterOffset());
	if (mem_op.GetExtend() != vixl::aarch64::NO_EXTEND) {
	return vixl::aarch64::Operand(mem_op.GetRegisterOffset(),
	mem_op.GetExtend(),
	mem_op.GetShiftAmount());
	} else if (mem_op.GetShift() != vixl::aarch64::NO_SHIFT) {
	return vixl::aarch64::Operand(mem_op.GetRegisterOffset(),
	mem_op.GetShift(),
	mem_op.GetShiftAmount());
	} else {
	LOG(FATAL) << "Should not reach here";
	UNREACHABLE();
	}
	}
	}

	inline bool AddSubCanEncodeAsImmediate(int64_t value) {
	// If `value` does not fit but `-value` does, VIXL will automatically use
	// the 'opposite' instruction.
	return vixl::aarch64::Assembler::IsImmAddSub(value)
	\|\| vixl::aarch64::Assembler::IsImmAddSub(-value);
	}

	inline bool Arm64CanEncodeConstantAsImmediate(HConstant* constant, HInstruction* instr) {
	int64_t value = CodeGenerator::GetInt64ValueOf(constant);

	// TODO: Improve this when IsSIMDConstantEncodable method is implemented in VIXL.
	if (instr->IsVecReplicateScalar()) {
	if (constant->IsLongConstant()) {
	return false;
	} else if (constant->IsFloatConstant()) {
	return vixl::aarch64::Assembler::IsImmFP32(constant->AsFloatConstant()->GetValue());
	} else if (constant->IsDoubleConstant()) {
	return vixl::aarch64::Assembler::IsImmFP64(constant->AsDoubleConstant()->GetValue());
	}
	return IsUint<8>(value);
	}

	// Code generation for Min/Max:
	// Cmp left_op, right_op
	// Csel dst, left_op, right_op, cond
	if (instr->IsMin() \|\| instr->IsMax()) {
	if (constant->GetUses().HasExactlyOneElement()) {
	// If value can be encoded as immediate for the Cmp, then let VIXL handle
	// the constant generation for the Csel.
	return AddSubCanEncodeAsImmediate(value);
	}
	// These values are encodable as immediates for Cmp and VIXL will use csinc and csinv
	// with the zr register as right_op, hence no constant generation is required.
	return constant->IsZeroBitPattern() \|\| constant->IsOne() \|\| constant->IsMinusOne();
	}

	// For single uses we let VIXL handle the constant generation since it will
	// use registers that are not managed by the register allocator (wip0, wip1).
	if (constant->GetUses().HasExactlyOneElement()) {
	return true;
	}

	// Our code generator ensures shift distances are within an encodable range.
	if (instr->IsRor()) {
	return true;
	}

	if (instr->IsAnd() \|\| instr->IsOr() \|\| instr->IsXor()) {
	// Uses logical operations.
	return vixl::aarch64::Assembler::IsImmLogical(value, vixl::aarch64::kXRegSize);
	} else if (instr->IsNeg()) {
	// Uses mov -immediate.
	return vixl::aarch64::Assembler::IsImmMovn(value, vixl::aarch64::kXRegSize);
	} else {
	DCHECK(instr->IsAdd() \|\|
	instr->IsIntermediateAddress() \|\|
	instr->IsBoundsCheck() \|\|
	instr->IsCompare() \|\|
	instr->IsCondition() \|\|
	instr->IsSub())
	<< instr->DebugName();
	// Uses aliases of ADD/SUB instructions.
	return AddSubCanEncodeAsImmediate(value);
	}
	}

	inline Location ARM64EncodableConstantOrRegister(HInstruction* constant,
	HInstruction* instr) {
	if (constant->IsConstant()
	&& Arm64CanEncodeConstantAsImmediate(constant->AsConstant(), instr)) {
	return Location::ConstantLocation(constant->AsConstant());
	}

	return Location::RequiresRegister();
	}

	// Check if registers in art register set have the same register code in vixl. If the register
	// codes are same, we can initialize vixl register list simply by the register masks. Currently,
	// only SP/WSP and ZXR/WZR codes are different between art and vixl.
	// Note: This function is only used for debug checks.
	inline bool ArtVixlRegCodeCoherentForRegSet(uint32_t art_core_registers,
	size_t num_core,
	uint32_t art_fpu_registers,
	size_t num_fpu) {
	// The register masks won't work if the number of register is larger than 32.
	DCHECK_GE(sizeof(art_core_registers) * 8, num_core);
	DCHECK_GE(sizeof(art_fpu_registers) * 8, num_fpu);
	for (size_t art_reg_code = 0; art_reg_code < num_core; ++art_reg_code) {
	if (RegisterSet::Contains(art_core_registers, art_reg_code)) {
	if (art_reg_code != static_cast<size_t>(VIXLRegCodeFromART(art_reg_code))) {
	return false;
	}
	}
	}
	// There is no register code translation for float registers.
	return true;
	}

	inline vixl::aarch64::Shift ShiftFromOpKind(HDataProcWithShifterOp::OpKind op_kind) {
	switch (op_kind) {
	case HDataProcWithShifterOp::kASR: return vixl::aarch64::ASR;
	case HDataProcWithShifterOp::kLSL: return vixl::aarch64::LSL;
	case HDataProcWithShifterOp::kLSR: return vixl::aarch64::LSR;
	default:
	LOG(FATAL) << "Unexpected op kind " << op_kind;
	UNREACHABLE();
	return vixl::aarch64::NO_SHIFT;
	}
	}

	inline vixl::aarch64::Extend ExtendFromOpKind(HDataProcWithShifterOp::OpKind op_kind) {
	switch (op_kind) {
	case HDataProcWithShifterOp::kUXTB: return vixl::aarch64::UXTB;
	case HDataProcWithShifterOp::kUXTH: return vixl::aarch64::UXTH;
	case HDataProcWithShifterOp::kUXTW: return vixl::aarch64::UXTW;
	case HDataProcWithShifterOp::kSXTB: return vixl::aarch64::SXTB;
	case HDataProcWithShifterOp::kSXTH: return vixl::aarch64::SXTH;
	case HDataProcWithShifterOp::kSXTW: return vixl::aarch64::SXTW;
	default:
	LOG(FATAL) << "Unexpected op kind " << op_kind;
	UNREACHABLE();
	return vixl::aarch64::NO_EXTEND;
	}
	}

	inline bool ShifterOperandSupportsExtension(HInstruction* instruction) {
	DCHECK(HasShifterOperand(instruction, InstructionSet::kArm64));
	// Although the `neg` instruction is an alias of the `sub` instruction, `HNeg`
	// does not support extension. This is because the `extended register` form
	// of the `sub` instruction interprets the left register with code 31 as the
	// stack pointer and not the zero register. (So does the `immediate` form.) In
	// the other form `shifted register, the register with code 31 is interpreted
	// as the zero register.
	return instruction->IsAdd() \|\| instruction->IsSub();
	}

	inline bool IsConstantZeroBitPattern(const HInstruction* instruction) {
	return instruction->IsConstant() && instruction->AsConstant()->IsZeroBitPattern();
	}

	} // namespace helpers
	} // namespace arm64
	} // namespace art

	#endif // ART_COMPILER_OPTIMIZING_COMMON_ARM64_H_