xref: /art/compiler/utils/x86_64/assembler_x86_64.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 "assembler_x86_64.h"

#include "base/casts.h"
#include "entrypoints/quick/quick_entrypoints.h"
#include "memory_region.h"
#include "thread.h"

namespace art {
namespace x86_64 {

std::ostream& operator<<(std::ostream& os, const CpuRegister& reg) {
  return os << reg.AsRegister();
}

std::ostream& operator<<(std::ostream& os, const XmmRegister& reg) {
  return os << reg.AsFloatRegister();
}

std::ostream& operator<<(std::ostream& os, const X87Register& reg) {
  return os << "ST" << static_cast<int>(reg);
}

void X86_64Assembler::call(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0xFF);
  EmitRegisterOperand(2, reg.LowBits());
}


void X86_64Assembler::call(const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(address);
  EmitUint8(0xFF);
  EmitOperand(2, address);
}


void X86_64Assembler::call(Label* label) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xE8);
  static const int kSize = 5;
  // Offset by one because we already have emitted the opcode.
  EmitLabel(label, kSize - 1);
}

void X86_64Assembler::pushq(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0x50 + reg.LowBits());
}


void X86_64Assembler::pushq(const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(address);
  EmitUint8(0xFF);
  EmitOperand(6, address);
}


void X86_64Assembler::pushq(const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // pushq only supports 32b immediate.
  if (imm.is_int8()) {
    EmitUint8(0x6A);
    EmitUint8(imm.value() & 0xFF);
  } else {
    EmitUint8(0x68);
    EmitImmediate(imm);
  }
}


void X86_64Assembler::popq(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0x58 + reg.LowBits());
}


void X86_64Assembler::popq(const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(address);
  EmitUint8(0x8F);
  EmitOperand(0, address);
}


void X86_64Assembler::movq(CpuRegister dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  if (imm.is_int32()) {
    // 32 bit. Note: sign-extends.
    EmitRex64(dst);
    EmitUint8(0xC7);
    EmitRegisterOperand(0, dst.LowBits());
    EmitInt32(static_cast<int32_t>(imm.value()));
  } else {
    EmitRex64(dst);
    EmitUint8(0xB8 + dst.LowBits());
    EmitInt64(imm.value());
  }
}


void X86_64Assembler::movl(CpuRegister dst, const Immediate& imm) {
  CHECK(imm.is_int32());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst);
  EmitUint8(0xB8 + dst.LowBits());
  EmitImmediate(imm);
}


void X86_64Assembler::movq(const Address& dst, const Immediate& imm) {
  CHECK(imm.is_int32());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst);
  EmitUint8(0xC7);
  EmitOperand(0, dst);
  EmitImmediate(imm);
}


void X86_64Assembler::movq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  // 0x89 is movq r/m64 <- r64, with op1 in r/m and op2 in reg: so reverse EmitRex64
  EmitRex64(src, dst);
  EmitUint8(0x89);
  EmitRegisterOperand(src.LowBits(), dst.LowBits());
}


void X86_64Assembler::movl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x8B);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::movq(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x8B);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movl(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x8B);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movq(const Address& dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(src, dst);
  EmitUint8(0x89);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movl(const Address& dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x89);
  EmitOperand(src.LowBits(), dst);
}

void X86_64Assembler::movl(const Address& dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst);
  EmitUint8(0xC7);
  EmitOperand(0, dst);
  EmitImmediate(imm);
}

void X86_64Assembler::movntl(const Address& dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0xC3);
  EmitOperand(src.LowBits(), dst);
}

void X86_64Assembler::movntq(const Address& dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0xC3);
  EmitOperand(src.LowBits(), dst);
}

void X86_64Assembler::cmov(Condition c, CpuRegister dst, CpuRegister src) {
  cmov(c, dst, src, true);
}

void X86_64Assembler::cmov(Condition c, CpuRegister dst, CpuRegister src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex(false, is64bit, dst.NeedsRex(), false, src.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x40 + c);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::cmov(Condition c, CpuRegister dst, const Address& src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  if (is64bit) {
    EmitRex64(dst, src);
  } else {
    EmitOptionalRex32(dst, src);
  }
  EmitUint8(0x0F);
  EmitUint8(0x40 + c);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movzxb(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalByteRegNormalizingRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xB6);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::movzxb(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  // Byte register is only in the source register form, so we don't use
  // EmitOptionalByteRegNormalizingRex32(dst, src);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xB6);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movsxb(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalByteRegNormalizingRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBE);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::movsxb(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  // Byte register is only in the source register form, so we don't use
  // EmitOptionalByteRegNormalizingRex32(dst, src);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBE);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movb(CpuRegister /*dst*/, const Address& /*src*/) {
  LOG(FATAL) << "Use movzxb or movsxb instead.";
}


void X86_64Assembler::movb(const Address& dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalByteRegNormalizingRex32(src, dst);
  EmitUint8(0x88);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movb(const Address& dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst);
  EmitUint8(0xC6);
  EmitOperand(Register::RAX, dst);
  CHECK(imm.is_int8());
  EmitUint8(imm.value() & 0xFF);
}


void X86_64Assembler::movzxw(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xB7);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::movzxw(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xB7);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movsxw(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBF);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::movsxw(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBF);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movw(CpuRegister /*dst*/, const Address& /*src*/) {
  LOG(FATAL) << "Use movzxw or movsxw instead.";
}


void X86_64Assembler::movw(const Address& dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOperandSizeOverride();
  EmitOptionalRex32(src, dst);
  EmitUint8(0x89);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movw(const Address& dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOperandSizeOverride();
  EmitOptionalRex32(dst);
  EmitUint8(0xC7);
  EmitOperand(Register::RAX, dst);
  CHECK(imm.is_uint16() || imm.is_int16());
  EmitUint8(imm.value() & 0xFF);
  EmitUint8(imm.value() >> 8);
}


void X86_64Assembler::leaq(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x8D);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::leal(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x8D);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movaps(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x28);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::movaps(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x28);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movups(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x10);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movaps(const Address& dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0x29);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movups(const Address& dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0x11);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movss(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x10);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movss(const Address& dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0x11);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movss(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(src, dst);  // Movss is MR encoding instead of the usual RM.
  EmitUint8(0x0F);
  EmitUint8(0x11);
  EmitXmmRegisterOperand(src.LowBits(), dst);
}


void X86_64Assembler::movsxd(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x63);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::movsxd(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x63);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movd(XmmRegister dst, CpuRegister src) {
  movd(dst, src, true);
}

void X86_64Assembler::movd(CpuRegister dst, XmmRegister src) {
  movd(dst, src, true);
}

void X86_64Assembler::movd(XmmRegister dst, CpuRegister src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, is64bit, dst.NeedsRex(), false, src.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x6E);
  EmitOperand(dst.LowBits(), Operand(src));
}

void X86_64Assembler::movd(CpuRegister dst, XmmRegister src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, is64bit, src.NeedsRex(), false, dst.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x7E);
  EmitOperand(src.LowBits(), Operand(dst));
}


void X86_64Assembler::addss(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x58);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::addss(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x58);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::subss(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5C);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::subss(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5C);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::mulss(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x59);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::mulss(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x59);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::divss(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5E);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::divss(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5E);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::addps(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x58);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::subps(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5C);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::mulps(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x59);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::divps(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5E);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::flds(const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitOperand(0, src);
}


void X86_64Assembler::fsts(const Address& dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitOperand(2, dst);
}


void X86_64Assembler::fstps(const Address& dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitOperand(3, dst);
}


void X86_64Assembler::movapd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x28);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::movapd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x28);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movupd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x10);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movapd(const Address& dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0x29);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movupd(const Address& dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0x11);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movsd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x10);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movsd(const Address& dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0x11);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movsd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(src, dst);  // Movsd is MR encoding instead of the usual RM.
  EmitUint8(0x0F);
  EmitUint8(0x11);
  EmitXmmRegisterOperand(src.LowBits(), dst);
}


void X86_64Assembler::addsd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x58);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::addsd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x58);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::subsd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5C);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::subsd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5C);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::mulsd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x59);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::mulsd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x59);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::divsd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5E);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::divsd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5E);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::addpd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x58);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::subpd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5C);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::mulpd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x59);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::divpd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5E);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::movdqa(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x6F);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::movdqa(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x6F);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movdqu(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x6F);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::movdqa(const Address& dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0x7F);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::movdqu(const Address& dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(src, dst);
  EmitUint8(0x0F);
  EmitUint8(0x7F);
  EmitOperand(src.LowBits(), dst);
}


void X86_64Assembler::paddb(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xFC);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::psubb(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xF8);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::paddw(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xFD);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::psubw(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xF9);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::pmullw(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xD5);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::paddd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xFE);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::psubd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xFA);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::pmulld(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x38);
  EmitUint8(0x40);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::paddq(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xD4);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::psubq(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xFB);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtsi2ss(XmmRegister dst, CpuRegister src) {
  cvtsi2ss(dst, src, false);
}


void X86_64Assembler::cvtsi2ss(XmmRegister dst, CpuRegister src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  if (is64bit) {
    // Emit a REX.W prefix if the operand size is 64 bits.
    EmitRex64(dst, src);
  } else {
    EmitOptionalRex32(dst, src);
  }
  EmitUint8(0x0F);
  EmitUint8(0x2A);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::cvtsi2ss(XmmRegister dst, const Address& src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  if (is64bit) {
    // Emit a REX.W prefix if the operand size is 64 bits.
    EmitRex64(dst, src);
  } else {
    EmitOptionalRex32(dst, src);
  }
  EmitUint8(0x0F);
  EmitUint8(0x2A);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtsi2sd(XmmRegister dst, CpuRegister src) {
  cvtsi2sd(dst, src, false);
}


void X86_64Assembler::cvtsi2sd(XmmRegister dst, CpuRegister src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  if (is64bit) {
    // Emit a REX.W prefix if the operand size is 64 bits.
    EmitRex64(dst, src);
  } else {
    EmitOptionalRex32(dst, src);
  }
  EmitUint8(0x0F);
  EmitUint8(0x2A);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::cvtsi2sd(XmmRegister dst, const Address& src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  if (is64bit) {
    // Emit a REX.W prefix if the operand size is 64 bits.
    EmitRex64(dst, src);
  } else {
    EmitOptionalRex32(dst, src);
  }
  EmitUint8(0x0F);
  EmitUint8(0x2A);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtss2si(CpuRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x2D);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtss2sd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5A);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtss2sd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5A);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtsd2si(CpuRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x2D);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvttss2si(CpuRegister dst, XmmRegister src) {
  cvttss2si(dst, src, false);
}


void X86_64Assembler::cvttss2si(CpuRegister dst, XmmRegister src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  if (is64bit) {
    // Emit a REX.W prefix if the operand size is 64 bits.
    EmitRex64(dst, src);
  } else {
    EmitOptionalRex32(dst, src);
  }
  EmitUint8(0x0F);
  EmitUint8(0x2C);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvttsd2si(CpuRegister dst, XmmRegister src) {
  cvttsd2si(dst, src, false);
}


void X86_64Assembler::cvttsd2si(CpuRegister dst, XmmRegister src, bool is64bit) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  if (is64bit) {
    // Emit a REX.W prefix if the operand size is 64 bits.
    EmitRex64(dst, src);
  } else {
    EmitOptionalRex32(dst, src);
  }
  EmitUint8(0x0F);
  EmitUint8(0x2C);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtsd2ss(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5A);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtsd2ss(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x5A);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::cvtdq2pd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xE6);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::comiss(XmmRegister a, XmmRegister b) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(a, b);
  EmitUint8(0x0F);
  EmitUint8(0x2F);
  EmitXmmRegisterOperand(a.LowBits(), b);
}


void X86_64Assembler::comiss(XmmRegister a, const Address& b) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(a, b);
  EmitUint8(0x0F);
  EmitUint8(0x2F);
  EmitOperand(a.LowBits(), b);
}


void X86_64Assembler::comisd(XmmRegister a, XmmRegister b) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(a, b);
  EmitUint8(0x0F);
  EmitUint8(0x2F);
  EmitXmmRegisterOperand(a.LowBits(), b);
}


void X86_64Assembler::comisd(XmmRegister a, const Address& b) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(a, b);
  EmitUint8(0x0F);
  EmitUint8(0x2F);
  EmitOperand(a.LowBits(), b);
}


void X86_64Assembler::ucomiss(XmmRegister a, XmmRegister b) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(a, b);
  EmitUint8(0x0F);
  EmitUint8(0x2E);
  EmitXmmRegisterOperand(a.LowBits(), b);
}


void X86_64Assembler::ucomiss(XmmRegister a, const Address& b) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(a, b);
  EmitUint8(0x0F);
  EmitUint8(0x2E);
  EmitOperand(a.LowBits(), b);
}


void X86_64Assembler::ucomisd(XmmRegister a, XmmRegister b) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(a, b);
  EmitUint8(0x0F);
  EmitUint8(0x2E);
  EmitXmmRegisterOperand(a.LowBits(), b);
}


void X86_64Assembler::ucomisd(XmmRegister a, const Address& b) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(a, b);
  EmitUint8(0x0F);
  EmitUint8(0x2E);
  EmitOperand(a.LowBits(), b);
}


void X86_64Assembler::roundsd(XmmRegister dst, XmmRegister src, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x3A);
  EmitUint8(0x0B);
  EmitXmmRegisterOperand(dst.LowBits(), src);
  EmitUint8(imm.value());
}


void X86_64Assembler::roundss(XmmRegister dst, XmmRegister src, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x3A);
  EmitUint8(0x0A);
  EmitXmmRegisterOperand(dst.LowBits(), src);
  EmitUint8(imm.value());
}


void X86_64Assembler::sqrtsd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x51);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::sqrtss(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x51);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::xorpd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x57);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::xorpd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x57);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::xorps(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x57);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::xorps(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x57);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::pxor(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xEF);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::andpd(XmmRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x54);
  EmitOperand(dst.LowBits(), src);
}

void X86_64Assembler::andpd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x54);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}

void X86_64Assembler::andps(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x54);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}

void X86_64Assembler::pand(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xDB);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}

void X86_64Assembler::orpd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x56);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}

void X86_64Assembler::orps(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x56);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}

void X86_64Assembler::por(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xEB);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}

void X86_64Assembler::shufpd(XmmRegister dst, XmmRegister src, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xC6);
  EmitXmmRegisterOperand(dst.LowBits(), src);
  EmitUint8(imm.value());
}


void X86_64Assembler::shufps(XmmRegister dst, XmmRegister src, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xC6);
  EmitXmmRegisterOperand(dst.LowBits(), src);
  EmitUint8(imm.value());
}


void X86_64Assembler::pshufd(XmmRegister dst, XmmRegister src, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x70);
  EmitXmmRegisterOperand(dst.LowBits(), src);
  EmitUint8(imm.value());
}


void X86_64Assembler::punpcklbw(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x60);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::punpcklwd(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x61);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::punpckldq(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x62);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::punpcklqdq(XmmRegister dst, XmmRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0x6C);
  EmitXmmRegisterOperand(dst.LowBits(), src);
}


void X86_64Assembler::psllw(XmmRegister reg, const Immediate& shift_count) {
  DCHECK(shift_count.is_uint8());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x71);
  EmitXmmRegisterOperand(6, reg);
  EmitUint8(shift_count.value());
}


void X86_64Assembler::pslld(XmmRegister reg, const Immediate& shift_count) {
  DCHECK(shift_count.is_uint8());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x72);
  EmitXmmRegisterOperand(6, reg);
  EmitUint8(shift_count.value());
}


void X86_64Assembler::psllq(XmmRegister reg, const Immediate& shift_count) {
  DCHECK(shift_count.is_uint8());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x73);
  EmitXmmRegisterOperand(6, reg);
  EmitUint8(shift_count.value());
}


void X86_64Assembler::psraw(XmmRegister reg, const Immediate& shift_count) {
  DCHECK(shift_count.is_uint8());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x71);
  EmitXmmRegisterOperand(4, reg);
  EmitUint8(shift_count.value());
}


void X86_64Assembler::psrad(XmmRegister reg, const Immediate& shift_count) {
  DCHECK(shift_count.is_uint8());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x72);
  EmitXmmRegisterOperand(4, reg);
  EmitUint8(shift_count.value());
}


void X86_64Assembler::psrlw(XmmRegister reg, const Immediate& shift_count) {
  DCHECK(shift_count.is_uint8());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x71);
  EmitXmmRegisterOperand(2, reg);
  EmitUint8(shift_count.value());
}


void X86_64Assembler::psrld(XmmRegister reg, const Immediate& shift_count) {
  DCHECK(shift_count.is_uint8());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x72);
  EmitXmmRegisterOperand(2, reg);
  EmitUint8(shift_count.value());
}


void X86_64Assembler::psrlq(XmmRegister reg, const Immediate& shift_count) {
  DCHECK(shift_count.is_uint8());
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0x73);
  EmitXmmRegisterOperand(2, reg);
  EmitUint8(shift_count.value());
}


void X86_64Assembler::fldl(const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDD);
  EmitOperand(0, src);
}


void X86_64Assembler::fstl(const Address& dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDD);
  EmitOperand(2, dst);
}


void X86_64Assembler::fstpl(const Address& dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDD);
  EmitOperand(3, dst);
}


void X86_64Assembler::fstsw() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x9B);
  EmitUint8(0xDF);
  EmitUint8(0xE0);
}


void X86_64Assembler::fnstcw(const Address& dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitOperand(7, dst);
}


void X86_64Assembler::fldcw(const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitOperand(5, src);
}


void X86_64Assembler::fistpl(const Address& dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDF);
  EmitOperand(7, dst);
}


void X86_64Assembler::fistps(const Address& dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDB);
  EmitOperand(3, dst);
}


void X86_64Assembler::fildl(const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDF);
  EmitOperand(5, src);
}


void X86_64Assembler::filds(const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDB);
  EmitOperand(0, src);
}


void X86_64Assembler::fincstp() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitUint8(0xF7);
}


void X86_64Assembler::ffree(const Immediate& index) {
  CHECK_LT(index.value(), 7);
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDD);
  EmitUint8(0xC0 + index.value());
}


void X86_64Assembler::fsin() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitUint8(0xFE);
}


void X86_64Assembler::fcos() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitUint8(0xFF);
}


void X86_64Assembler::fptan() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitUint8(0xF2);
}

void X86_64Assembler::fucompp() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xDA);
  EmitUint8(0xE9);
}


void X86_64Assembler::fprem() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xD9);
  EmitUint8(0xF8);
}


void X86_64Assembler::xchgl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  // There is a short version for rax.
  // It's a bit awkward, as CpuRegister has a const field, so assignment and thus swapping doesn't
  // work.
  const bool src_rax = src.AsRegister() == RAX;
  const bool dst_rax = dst.AsRegister() == RAX;
  if (src_rax || dst_rax) {
    EmitOptionalRex32(src_rax ? dst : src);
    EmitUint8(0x90 + (src_rax ? dst.LowBits() : src.LowBits()));
    return;
  }

  // General case.
  EmitOptionalRex32(src, dst);
  EmitUint8(0x87);
  EmitRegisterOperand(src.LowBits(), dst.LowBits());
}


void X86_64Assembler::xchgq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  // There is a short version for rax.
  // It's a bit awkward, as CpuRegister has a const field, so assignment and thus swapping doesn't
  // work.
  const bool src_rax = src.AsRegister() == RAX;
  const bool dst_rax = dst.AsRegister() == RAX;
  if (src_rax || dst_rax) {
    // If src == target, emit a nop instead.
    if (src_rax && dst_rax) {
      EmitUint8(0x90);
    } else {
      EmitRex64(src_rax ? dst : src);
      EmitUint8(0x90 + (src_rax ? dst.LowBits() : src.LowBits()));
    }
    return;
  }

  // General case.
  EmitRex64(src, dst);
  EmitUint8(0x87);
  EmitRegisterOperand(src.LowBits(), dst.LowBits());
}


void X86_64Assembler::xchgl(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x87);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::cmpb(const Address& address, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());
  EmitOptionalRex32(address);
  EmitUint8(0x80);
  EmitOperand(7, address);
  EmitUint8(imm.value() & 0xFF);
}


void X86_64Assembler::cmpw(const Address& address, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());
  EmitOperandSizeOverride();
  EmitOptionalRex32(address);
  EmitComplex(7, address, imm);
}


void X86_64Assembler::cmpl(CpuRegister reg, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());
  EmitOptionalRex32(reg);
  EmitComplex(7, Operand(reg), imm);
}


void X86_64Assembler::cmpl(CpuRegister reg0, CpuRegister reg1) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg0, reg1);
  EmitUint8(0x3B);
  EmitOperand(reg0.LowBits(), Operand(reg1));
}


void X86_64Assembler::cmpl(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x3B);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::cmpl(const Address& address, CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x39);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::cmpl(const Address& address, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());
  EmitOptionalRex32(address);
  EmitComplex(7, address, imm);
}


void X86_64Assembler::cmpq(CpuRegister reg0, CpuRegister reg1) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg0, reg1);
  EmitUint8(0x3B);
  EmitOperand(reg0.LowBits(), Operand(reg1));
}


void X86_64Assembler::cmpq(CpuRegister reg, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // cmpq only supports 32b immediate.
  EmitRex64(reg);
  EmitComplex(7, Operand(reg), imm);
}


void X86_64Assembler::cmpq(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg, address);
  EmitUint8(0x3B);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::cmpq(const Address& address, const Immediate& imm) {
  CHECK(imm.is_int32());  // cmpq only supports 32b immediate.
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(address);
  EmitComplex(7, address, imm);
}


void X86_64Assembler::addl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x03);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::addl(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x03);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::testl(CpuRegister reg1, CpuRegister reg2) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg1, reg2);
  EmitUint8(0x85);
  EmitRegisterOperand(reg1.LowBits(), reg2.LowBits());
}


void X86_64Assembler::testl(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x85);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::testl(CpuRegister reg, const Immediate& immediate) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  // For registers that have a byte variant (RAX, RBX, RCX, and RDX)
  // we only test the byte CpuRegister to keep the encoding short.
  if (immediate.is_uint8() && reg.AsRegister() < 4) {
    // Use zero-extended 8-bit immediate.
    if (reg.AsRegister() == RAX) {
      EmitUint8(0xA8);
    } else {
      EmitUint8(0xF6);
      EmitUint8(0xC0 + reg.AsRegister());
    }
    EmitUint8(immediate.value() & 0xFF);
  } else if (reg.AsRegister() == RAX) {
    // Use short form if the destination is RAX.
    EmitUint8(0xA9);
    EmitImmediate(immediate);
  } else {
    EmitOptionalRex32(reg);
    EmitUint8(0xF7);
    EmitOperand(0, Operand(reg));
    EmitImmediate(immediate);
  }
}


void X86_64Assembler::testq(CpuRegister reg1, CpuRegister reg2) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg1, reg2);
  EmitUint8(0x85);
  EmitRegisterOperand(reg1.LowBits(), reg2.LowBits());
}


void X86_64Assembler::testq(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg, address);
  EmitUint8(0x85);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::testb(const Address& dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst);
  EmitUint8(0xF6);
  EmitOperand(Register::RAX, dst);
  CHECK(imm.is_int8());
  EmitUint8(imm.value() & 0xFF);
}


void X86_64Assembler::testl(const Address& dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst);
  EmitUint8(0xF7);
  EmitOperand(0, dst);
  EmitImmediate(imm);
}


void X86_64Assembler::andl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x23);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::andl(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x23);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::andl(CpuRegister dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst);
  EmitComplex(4, Operand(dst), imm);
}


void X86_64Assembler::andq(CpuRegister reg, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // andq only supports 32b immediate.
  EmitRex64(reg);
  EmitComplex(4, Operand(reg), imm);
}


void X86_64Assembler::andq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x23);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::andq(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x23);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::orl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0B);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::orl(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x0B);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::orl(CpuRegister dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst);
  EmitComplex(1, Operand(dst), imm);
}


void X86_64Assembler::orq(CpuRegister dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // orq only supports 32b immediate.
  EmitRex64(dst);
  EmitComplex(1, Operand(dst), imm);
}


void X86_64Assembler::orq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x0B);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::orq(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x0B);
  EmitOperand(dst.LowBits(), src);
}


void X86_64Assembler::xorl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x33);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::xorl(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x33);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::xorl(CpuRegister dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst);
  EmitComplex(6, Operand(dst), imm);
}


void X86_64Assembler::xorq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x33);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::xorq(CpuRegister dst, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // xorq only supports 32b immediate.
  EmitRex64(dst);
  EmitComplex(6, Operand(dst), imm);
}

void X86_64Assembler::xorq(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x33);
  EmitOperand(dst.LowBits(), src);
}


#if 0
void X86_64Assembler::rex(bool force, bool w, Register* r, Register* x, Register* b) {
  // REX.WRXB
  // W - 64-bit operand
  // R - MODRM.reg
  // X - SIB.index
  // B - MODRM.rm/SIB.base
  uint8_t rex = force ? 0x40 : 0;
  if (w) {
    rex |= 0x48;  // REX.W000
  }
  if (r != nullptr && *r >= Register::R8 && *r < Register::kNumberOfCpuRegisters) {
    rex |= 0x44;  // REX.0R00
    *r = static_cast<Register>(*r - 8);
  }
  if (x != nullptr && *x >= Register::R8 && *x < Register::kNumberOfCpuRegisters) {
    rex |= 0x42;  // REX.00X0
    *x = static_cast<Register>(*x - 8);
  }
  if (b != nullptr && *b >= Register::R8 && *b < Register::kNumberOfCpuRegisters) {
    rex |= 0x41;  // REX.000B
    *b = static_cast<Register>(*b - 8);
  }
  if (rex != 0) {
    EmitUint8(rex);
  }
}

void X86_64Assembler::rex_reg_mem(bool force, bool w, Register* dst, const Address& mem) {
  // REX.WRXB
  // W - 64-bit operand
  // R - MODRM.reg
  // X - SIB.index
  // B - MODRM.rm/SIB.base
  uint8_t rex = mem->rex();
  if (force) {
    rex |= 0x40;  // REX.0000
  }
  if (w) {
    rex |= 0x48;  // REX.W000
  }
  if (dst != nullptr && *dst >= Register::R8 && *dst < Register::kNumberOfCpuRegisters) {
    rex |= 0x44;  // REX.0R00
    *dst = static_cast<Register>(*dst - 8);
  }
  if (rex != 0) {
    EmitUint8(rex);
  }
}

void rex_mem_reg(bool force, bool w, Address* mem, Register* src);
#endif

void X86_64Assembler::addl(CpuRegister reg, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitComplex(0, Operand(reg), imm);
}


void X86_64Assembler::addq(CpuRegister reg, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // addq only supports 32b immediate.
  EmitRex64(reg);
  EmitComplex(0, Operand(reg), imm);
}


void X86_64Assembler::addq(CpuRegister dst, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, address);
  EmitUint8(0x03);
  EmitOperand(dst.LowBits(), address);
}


void X86_64Assembler::addq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  // 0x01 is addq r/m64 <- r/m64 + r64, with op1 in r/m and op2 in reg: so reverse EmitRex64
  EmitRex64(src, dst);
  EmitUint8(0x01);
  EmitRegisterOperand(src.LowBits(), dst.LowBits());
}


void X86_64Assembler::addl(const Address& address, CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x01);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::addl(const Address& address, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(address);
  EmitComplex(0, address, imm);
}


void X86_64Assembler::subl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x2B);
  EmitOperand(dst.LowBits(), Operand(src));
}


void X86_64Assembler::subl(CpuRegister reg, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitComplex(5, Operand(reg), imm);
}


void X86_64Assembler::subq(CpuRegister reg, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // subq only supports 32b immediate.
  EmitRex64(reg);
  EmitComplex(5, Operand(reg), imm);
}


void X86_64Assembler::subq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x2B);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::subq(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg, address);
  EmitUint8(0x2B);
  EmitOperand(reg.LowBits() & 7, address);
}


void X86_64Assembler::subl(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x2B);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::cdq() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x99);
}


void X86_64Assembler::cqo() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64();
  EmitUint8(0x99);
}


void X86_64Assembler::idivl(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0xF7);
  EmitUint8(0xF8 | reg.LowBits());
}


void X86_64Assembler::idivq(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg);
  EmitUint8(0xF7);
  EmitUint8(0xF8 | reg.LowBits());
}


void X86_64Assembler::imull(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xAF);
  EmitOperand(dst.LowBits(), Operand(src));
}

void X86_64Assembler::imull(CpuRegister dst, CpuRegister src, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // imull only supports 32b immediate.

  EmitOptionalRex32(dst, src);

  // See whether imm can be represented as a sign-extended 8bit value.
  int32_t v32 = static_cast<int32_t>(imm.value());
  if (IsInt<8>(v32)) {
    // Sign-extension works.
    EmitUint8(0x6B);
    EmitOperand(dst.LowBits(), Operand(src));
    EmitUint8(static_cast<uint8_t>(v32 & 0xFF));
  } else {
    // Not representable, use full immediate.
    EmitUint8(0x69);
    EmitOperand(dst.LowBits(), Operand(src));
    EmitImmediate(imm);
  }
}


void X86_64Assembler::imull(CpuRegister reg, const Immediate& imm) {
  imull(reg, reg, imm);
}


void X86_64Assembler::imull(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x0F);
  EmitUint8(0xAF);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::imulq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xAF);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}


void X86_64Assembler::imulq(CpuRegister reg, const Immediate& imm) {
  imulq(reg, reg, imm);
}

void X86_64Assembler::imulq(CpuRegister dst, CpuRegister reg, const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int32());  // imulq only supports 32b immediate.

  EmitRex64(dst, reg);

  // See whether imm can be represented as a sign-extended 8bit value.
  int64_t v64 = imm.value();
  if (IsInt<8>(v64)) {
    // Sign-extension works.
    EmitUint8(0x6B);
    EmitOperand(dst.LowBits(), Operand(reg));
    EmitUint8(static_cast<uint8_t>(v64 & 0xFF));
  } else {
    // Not representable, use full immediate.
    EmitUint8(0x69);
    EmitOperand(dst.LowBits(), Operand(reg));
    EmitImmediate(imm);
  }
}

void X86_64Assembler::imulq(CpuRegister reg, const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg, address);
  EmitUint8(0x0F);
  EmitUint8(0xAF);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::imull(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0xF7);
  EmitOperand(5, Operand(reg));
}


void X86_64Assembler::imulq(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg);
  EmitUint8(0xF7);
  EmitOperand(5, Operand(reg));
}


void X86_64Assembler::imull(const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(address);
  EmitUint8(0xF7);
  EmitOperand(5, address);
}


void X86_64Assembler::mull(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0xF7);
  EmitOperand(4, Operand(reg));
}


void X86_64Assembler::mull(const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(address);
  EmitUint8(0xF7);
  EmitOperand(4, address);
}


void X86_64Assembler::shll(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(false, 4, reg, imm);
}


void X86_64Assembler::shlq(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(true, 4, reg, imm);
}


void X86_64Assembler::shll(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(false, 4, operand, shifter);
}


void X86_64Assembler::shlq(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(true, 4, operand, shifter);
}


void X86_64Assembler::shrl(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(false, 5, reg, imm);
}


void X86_64Assembler::shrq(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(true, 5, reg, imm);
}


void X86_64Assembler::shrl(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(false, 5, operand, shifter);
}


void X86_64Assembler::shrq(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(true, 5, operand, shifter);
}


void X86_64Assembler::sarl(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(false, 7, reg, imm);
}


void X86_64Assembler::sarl(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(false, 7, operand, shifter);
}


void X86_64Assembler::sarq(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(true, 7, reg, imm);
}


void X86_64Assembler::sarq(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(true, 7, operand, shifter);
}


void X86_64Assembler::roll(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(false, 0, reg, imm);
}


void X86_64Assembler::roll(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(false, 0, operand, shifter);
}


void X86_64Assembler::rorl(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(false, 1, reg, imm);
}


void X86_64Assembler::rorl(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(false, 1, operand, shifter);
}


void X86_64Assembler::rolq(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(true, 0, reg, imm);
}


void X86_64Assembler::rolq(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(true, 0, operand, shifter);
}


void X86_64Assembler::rorq(CpuRegister reg, const Immediate& imm) {
  EmitGenericShift(true, 1, reg, imm);
}


void X86_64Assembler::rorq(CpuRegister operand, CpuRegister shifter) {
  EmitGenericShift(true, 1, operand, shifter);
}


void X86_64Assembler::negl(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0xF7);
  EmitOperand(3, Operand(reg));
}


void X86_64Assembler::negq(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg);
  EmitUint8(0xF7);
  EmitOperand(3, Operand(reg));
}


void X86_64Assembler::notl(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0xF7);
  EmitUint8(0xD0 | reg.LowBits());
}


void X86_64Assembler::notq(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg);
  EmitUint8(0xF7);
  EmitOperand(2, Operand(reg));
}


void X86_64Assembler::enter(const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xC8);
  CHECK(imm.is_uint16()) << imm.value();
  EmitUint8(imm.value() & 0xFF);
  EmitUint8((imm.value() >> 8) & 0xFF);
  EmitUint8(0x00);
}


void X86_64Assembler::leave() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xC9);
}


void X86_64Assembler::ret() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xC3);
}


void X86_64Assembler::ret(const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xC2);
  CHECK(imm.is_uint16());
  EmitUint8(imm.value() & 0xFF);
  EmitUint8((imm.value() >> 8) & 0xFF);
}



void X86_64Assembler::nop() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x90);
}


void X86_64Assembler::int3() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xCC);
}


void X86_64Assembler::hlt() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF4);
}


void X86_64Assembler::j(Condition condition, Label* label) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  if (label->IsBound()) {
    static const int kShortSize = 2;
    static const int kLongSize = 6;
    int offset = label->Position() - buffer_.Size();
    CHECK_LE(offset, 0);
    if (IsInt<8>(offset - kShortSize)) {
      EmitUint8(0x70 + condition);
      EmitUint8((offset - kShortSize) & 0xFF);
    } else {
      EmitUint8(0x0F);
      EmitUint8(0x80 + condition);
      EmitInt32(offset - kLongSize);
    }
  } else {
    EmitUint8(0x0F);
    EmitUint8(0x80 + condition);
    EmitLabelLink(label);
  }
}


void X86_64Assembler::j(Condition condition, NearLabel* label) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  if (label->IsBound()) {
    static const int kShortSize = 2;
    int offset = label->Position() - buffer_.Size();
    CHECK_LE(offset, 0);
    CHECK(IsInt<8>(offset - kShortSize));
    EmitUint8(0x70 + condition);
    EmitUint8((offset - kShortSize) & 0xFF);
  } else {
    EmitUint8(0x70 + condition);
    EmitLabelLink(label);
  }
}


void X86_64Assembler::jrcxz(NearLabel* label) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  if (label->IsBound()) {
    static const int kShortSize = 2;
    int offset = label->Position() - buffer_.Size();
    CHECK_LE(offset, 0);
    CHECK(IsInt<8>(offset - kShortSize));
    EmitUint8(0xE3);
    EmitUint8((offset - kShortSize) & 0xFF);
  } else {
    EmitUint8(0xE3);
    EmitLabelLink(label);
  }
}


void X86_64Assembler::jmp(CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg);
  EmitUint8(0xFF);
  EmitRegisterOperand(4, reg.LowBits());
}

void X86_64Assembler::jmp(const Address& address) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(address);
  EmitUint8(0xFF);
  EmitOperand(4, address);
}

void X86_64Assembler::jmp(Label* label) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  if (label->IsBound()) {
    static const int kShortSize = 2;
    static const int kLongSize = 5;
    int offset = label->Position() - buffer_.Size();
    CHECK_LE(offset, 0);
    if (IsInt<8>(offset - kShortSize)) {
      EmitUint8(0xEB);
      EmitUint8((offset - kShortSize) & 0xFF);
    } else {
      EmitUint8(0xE9);
      EmitInt32(offset - kLongSize);
    }
  } else {
    EmitUint8(0xE9);
    EmitLabelLink(label);
  }
}


void X86_64Assembler::jmp(NearLabel* label) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  if (label->IsBound()) {
    static const int kShortSize = 2;
    int offset = label->Position() - buffer_.Size();
    CHECK_LE(offset, 0);
    CHECK(IsInt<8>(offset - kShortSize));
    EmitUint8(0xEB);
    EmitUint8((offset - kShortSize) & 0xFF);
  } else {
    EmitUint8(0xEB);
    EmitLabelLink(label);
  }
}


void X86_64Assembler::rep_movsw() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitUint8(0xF3);
  EmitUint8(0xA5);
}


X86_64Assembler* X86_64Assembler::lock() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF0);
  return this;
}


void X86_64Assembler::cmpxchgl(const Address& address, CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(reg, address);
  EmitUint8(0x0F);
  EmitUint8(0xB1);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::cmpxchgq(const Address& address, CpuRegister reg) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(reg, address);
  EmitUint8(0x0F);
  EmitUint8(0xB1);
  EmitOperand(reg.LowBits(), address);
}


void X86_64Assembler::mfence() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x0F);
  EmitUint8(0xAE);
  EmitUint8(0xF0);
}


X86_64Assembler* X86_64Assembler::gs() {
  // TODO: gs is a prefix and not an instruction
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x65);
  return this;
}


void X86_64Assembler::AddImmediate(CpuRegister reg, const Immediate& imm) {
  int value = imm.value();
  if (value != 0) {
    if (value > 0) {
      addl(reg, imm);
    } else {
      subl(reg, Immediate(value));
    }
  }
}


void X86_64Assembler::setcc(Condition condition, CpuRegister dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  // RSP, RBP, RDI, RSI need rex prefix (else the pattern encodes ah/bh/ch/dh).
  if (dst.NeedsRex() || dst.AsRegister() > 3) {
    EmitOptionalRex(true, false, false, false, dst.NeedsRex());
  }
  EmitUint8(0x0F);
  EmitUint8(0x90 + condition);
  EmitUint8(0xC0 + dst.LowBits());
}

void X86_64Assembler::bswapl(CpuRegister dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex(false, false, false, false, dst.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0xC8 + dst.LowBits());
}

void X86_64Assembler::bswapq(CpuRegister dst) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex(false, true, false, false, dst.NeedsRex());
  EmitUint8(0x0F);
  EmitUint8(0xC8 + dst.LowBits());
}

void X86_64Assembler::bsfl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBC);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}

void X86_64Assembler::bsfl(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBC);
  EmitOperand(dst.LowBits(), src);
}

void X86_64Assembler::bsfq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBC);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}

void X86_64Assembler::bsfq(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBC);
  EmitOperand(dst.LowBits(), src);
}

void X86_64Assembler::bsrl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBD);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}

void X86_64Assembler::bsrl(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBD);
  EmitOperand(dst.LowBits(), src);
}

void X86_64Assembler::bsrq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBD);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}

void X86_64Assembler::bsrq(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitRex64(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xBD);
  EmitOperand(dst.LowBits(), src);
}

void X86_64Assembler::popcntl(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xB8);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}

void X86_64Assembler::popcntl(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitOptionalRex32(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xB8);
  EmitOperand(dst.LowBits(), src);
}

void X86_64Assembler::popcntq(CpuRegister dst, CpuRegister src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitRex64(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xB8);
  EmitRegisterOperand(dst.LowBits(), src.LowBits());
}

void X86_64Assembler::popcntq(CpuRegister dst, const Address& src) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitRex64(dst, src);
  EmitUint8(0x0F);
  EmitUint8(0xB8);
  EmitOperand(dst.LowBits(), src);
}

void X86_64Assembler::repne_scasb() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF2);
  EmitUint8(0xAE);
}

void X86_64Assembler::repne_scasw() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitUint8(0xF2);
  EmitUint8(0xAF);
}

void X86_64Assembler::repe_cmpsw() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0x66);
  EmitUint8(0xF3);
  EmitUint8(0xA7);
}


void X86_64Assembler::repe_cmpsl() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitUint8(0xA7);
}


void X86_64Assembler::repe_cmpsq() {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  EmitUint8(0xF3);
  EmitRex64();
  EmitUint8(0xA7);
}


void X86_64Assembler::LoadDoubleConstant(XmmRegister dst, double value) {
  // TODO: Need to have a code constants table.
  int64_t constant = bit_cast<int64_t, double>(value);
  pushq(Immediate(High32Bits(constant)));
  pushq(Immediate(Low32Bits(constant)));
  movsd(dst, Address(CpuRegister(RSP), 0));
  addq(CpuRegister(RSP), Immediate(2 * sizeof(intptr_t)));
}


void X86_64Assembler::Align(int alignment, int offset) {
  CHECK(IsPowerOfTwo(alignment));
  // Emit nop instruction until the real position is aligned.
  while (((offset + buffer_.GetPosition()) & (alignment-1)) != 0) {
    nop();
  }
}


void X86_64Assembler::Bind(Label* label) {
  int bound = buffer_.Size();
  CHECK(!label->IsBound());  // Labels can only be bound once.
  while (label->IsLinked()) {
    int position = label->LinkPosition();
    int next = buffer_.Load<int32_t>(position);
    buffer_.Store<int32_t>(position, bound - (position + 4));
    label->position_ = next;
  }
  label->BindTo(bound);
}


void X86_64Assembler::Bind(NearLabel* label) {
  int bound = buffer_.Size();
  CHECK(!label->IsBound());  // Labels can only be bound once.
  while (label->IsLinked()) {
    int position = label->LinkPosition();
    uint8_t delta = buffer_.Load<uint8_t>(position);
    int offset = bound - (position + 1);
    CHECK(IsInt<8>(offset));
    buffer_.Store<int8_t>(position, offset);
    label->position_ = delta != 0u ? label->position_ - delta : 0;
  }
  label->BindTo(bound);
}


void X86_64Assembler::EmitOperand(uint8_t reg_or_opcode, const Operand& operand) {
  CHECK_GE(reg_or_opcode, 0);
  CHECK_LT(reg_or_opcode, 8);
  const int length = operand.length_;
  CHECK_GT(length, 0);
  // Emit the ModRM byte updated with the given reg value.
  CHECK_EQ(operand.encoding_[0] & 0x38, 0);
  EmitUint8(operand.encoding_[0] + (reg_or_opcode << 3));
  // Emit the rest of the encoded operand.
  for (int i = 1; i < length; i++) {
    EmitUint8(operand.encoding_[i]);
  }
  AssemblerFixup* fixup = operand.GetFixup();
  if (fixup != nullptr) {
    EmitFixup(fixup);
  }
}


void X86_64Assembler::EmitImmediate(const Immediate& imm) {
  if (imm.is_int32()) {
    EmitInt32(static_cast<int32_t>(imm.value()));
  } else {
    EmitInt64(imm.value());
  }
}


void X86_64Assembler::EmitComplex(uint8_t reg_or_opcode,
                                  const Operand& operand,
                                  const Immediate& immediate) {
  CHECK_GE(reg_or_opcode, 0);
  CHECK_LT(reg_or_opcode, 8);
  if (immediate.is_int8()) {
    // Use sign-extended 8-bit immediate.
    EmitUint8(0x83);
    EmitOperand(reg_or_opcode, operand);
    EmitUint8(immediate.value() & 0xFF);
  } else if (operand.IsRegister(CpuRegister(RAX))) {
    // Use short form if the destination is eax.
    EmitUint8(0x05 + (reg_or_opcode << 3));
    EmitImmediate(immediate);
  } else {
    EmitUint8(0x81);
    EmitOperand(reg_or_opcode, operand);
    EmitImmediate(immediate);
  }
}


void X86_64Assembler::EmitLabel(Label* label, int instruction_size) {
  if (label->IsBound()) {
    int offset = label->Position() - buffer_.Size();
    CHECK_LE(offset, 0);
    EmitInt32(offset - instruction_size);
  } else {
    EmitLabelLink(label);
  }
}


void X86_64Assembler::EmitLabelLink(Label* label) {
  CHECK(!label->IsBound());
  int position = buffer_.Size();
  EmitInt32(label->position_);
  label->LinkTo(position);
}


void X86_64Assembler::EmitLabelLink(NearLabel* label) {
  CHECK(!label->IsBound());
  int position = buffer_.Size();
  if (label->IsLinked()) {
    // Save the delta in the byte that we have to play with.
    uint32_t delta = position - label->LinkPosition();
    CHECK(IsUint<8>(delta));
    EmitUint8(delta & 0xFF);
  } else {
    EmitUint8(0);
  }
  label->LinkTo(position);
}


void X86_64Assembler::EmitGenericShift(bool wide,
                                       int reg_or_opcode,
                                       CpuRegister reg,
                                       const Immediate& imm) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK(imm.is_int8());
  if (wide) {
    EmitRex64(reg);
  } else {
    EmitOptionalRex32(reg);
  }
  if (imm.value() == 1) {
    EmitUint8(0xD1);
    EmitOperand(reg_or_opcode, Operand(reg));
  } else {
    EmitUint8(0xC1);
    EmitOperand(reg_or_opcode, Operand(reg));
    EmitUint8(imm.value() & 0xFF);
  }
}


void X86_64Assembler::EmitGenericShift(bool wide,
                                       int reg_or_opcode,
                                       CpuRegister operand,
                                       CpuRegister shifter) {
  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
  CHECK_EQ(shifter.AsRegister(), RCX);
  if (wide) {
    EmitRex64(operand);
  } else {
    EmitOptionalRex32(operand);
  }
  EmitUint8(0xD3);
  EmitOperand(reg_or_opcode, Operand(operand));
}

void X86_64Assembler::EmitOptionalRex(bool force, bool w, bool r, bool x, bool b) {
  // REX.WRXB
  // W - 64-bit operand
  // R - MODRM.reg
  // X - SIB.index
  // B - MODRM.rm/SIB.base
  uint8_t rex = force ? 0x40 : 0;
  if (w) {
    rex |= 0x48;  // REX.W000
  }
  if (r) {
    rex |= 0x44;  // REX.0R00
  }
  if (x) {
    rex |= 0x42;  // REX.00X0
  }
  if (b) {
    rex |= 0x41;  // REX.000B
  }
  if (rex != 0) {
    EmitUint8(rex);
  }
}

void X86_64Assembler::EmitOptionalRex32(CpuRegister reg) {
  EmitOptionalRex(false, false, false, false, reg.NeedsRex());
}

void X86_64Assembler::EmitOptionalRex32(CpuRegister dst, CpuRegister src) {
  EmitOptionalRex(false, false, dst.NeedsRex(), false, src.NeedsRex());
}

void X86_64Assembler::EmitOptionalRex32(XmmRegister dst, XmmRegister src) {
  EmitOptionalRex(false, false, dst.NeedsRex(), false, src.NeedsRex());
}

void X86_64Assembler::EmitOptionalRex32(CpuRegister dst, XmmRegister src) {
  EmitOptionalRex(false, false, dst.NeedsRex(), false, src.NeedsRex());
}

void X86_64Assembler::EmitOptionalRex32(XmmRegister dst, CpuRegister src) {
  EmitOptionalRex(false, false, dst.NeedsRex(), false, src.NeedsRex());
}

void X86_64Assembler::EmitOptionalRex32(const Operand& operand) {
  uint8_t rex = operand.rex();
  if (rex != 0) {
    EmitUint8(rex);
  }
}

void X86_64Assembler::EmitOptionalRex32(CpuRegister dst, const Operand& operand) {
  uint8_t rex = operand.rex();
  if (dst.NeedsRex()) {
    rex |= 0x44;  // REX.0R00
  }
  if (rex != 0) {
    EmitUint8(rex);
  }
}

void X86_64Assembler::EmitOptionalRex32(XmmRegister dst, const Operand& operand) {
  uint8_t rex = operand.rex();
  if (dst.NeedsRex()) {
    rex |= 0x44;  // REX.0R00
  }
  if (rex != 0) {
    EmitUint8(rex);
  }
}

void X86_64Assembler::EmitRex64() {
  EmitOptionalRex(false, true, false, false, false);
}

void X86_64Assembler::EmitRex64(CpuRegister reg) {
  EmitOptionalRex(false, true, false, false, reg.NeedsRex());
}

void X86_64Assembler::EmitRex64(const Operand& operand) {
  uint8_t rex = operand.rex();
  rex |= 0x48;  // REX.W000
  EmitUint8(rex);
}

void X86_64Assembler::EmitRex64(CpuRegister dst, CpuRegister src) {
  EmitOptionalRex(false, true, dst.NeedsRex(), false, src.NeedsRex());
}

void X86_64Assembler::EmitRex64(XmmRegister dst, CpuRegister src) {
  EmitOptionalRex(false, true, dst.NeedsRex(), false, src.NeedsRex());
}

void X86_64Assembler::EmitRex64(CpuRegister dst, XmmRegister src) {
  EmitOptionalRex(false, true, dst.NeedsRex(), false, src.NeedsRex());
}

void X86_64Assembler::EmitRex64(CpuRegister dst, const Operand& operand) {
  uint8_t rex = 0x48 | operand.rex();  // REX.W000
  if (dst.NeedsRex()) {
    rex |= 0x44;  // REX.0R00
  }
  EmitUint8(rex);
}

void X86_64Assembler::EmitRex64(XmmRegister dst, const Operand& operand) {
  uint8_t rex = 0x48 | operand.rex();  // REX.W000
  if (dst.NeedsRex()) {
    rex |= 0x44;  // REX.0R00
  }
  EmitUint8(rex);
}

void X86_64Assembler::EmitOptionalByteRegNormalizingRex32(CpuRegister dst, CpuRegister src) {
  // For src, SPL, BPL, SIL, DIL need the rex prefix.
  bool force = src.AsRegister() > 3;
  EmitOptionalRex(force, false, dst.NeedsRex(), false, src.NeedsRex());
}

void X86_64Assembler::EmitOptionalByteRegNormalizingRex32(CpuRegister dst, const Operand& operand) {
  uint8_t rex = operand.rex();
  // For dst, SPL, BPL, SIL, DIL need the rex prefix.
  bool force = dst.AsRegister() > 3;
  if (force) {
    rex |= 0x40;  // REX.0000
  }
  if (dst.NeedsRex()) {
    rex |= 0x44;  // REX.0R00
  }
  if (rex != 0) {
    EmitUint8(rex);
  }
}

void X86_64Assembler::AddConstantArea() {
  ArrayRef<const int32_t> area = constant_area_.GetBuffer();
  for (size_t i = 0, e = area.size(); i < e; i++) {
    AssemblerBuffer::EnsureCapacity ensured(&buffer_);
    EmitInt32(area[i]);
  }
}

size_t ConstantArea::AppendInt32(int32_t v) {
  size_t result = buffer_.size() * elem_size_;
  buffer_.push_back(v);
  return result;
}

size_t ConstantArea::AddInt32(int32_t v) {
  // Look for an existing match.
  for (size_t i = 0, e = buffer_.size(); i < e; i++) {
    if (v == buffer_[i]) {
      return i * elem_size_;
    }
  }

  // Didn't match anything.
  return AppendInt32(v);
}

size_t ConstantArea::AddInt64(int64_t v) {
  int32_t v_low = v;
  int32_t v_high = v >> 32;
  if (buffer_.size() > 1) {
    // Ensure we don't pass the end of the buffer.
    for (size_t i = 0, e = buffer_.size() - 1; i < e; i++) {
      if (v_low == buffer_[i] && v_high == buffer_[i + 1]) {
        return i * elem_size_;
      }
    }
  }

  // Didn't match anything.
  size_t result = buffer_.size() * elem_size_;
  buffer_.push_back(v_low);
  buffer_.push_back(v_high);
  return result;
}

size_t ConstantArea::AddDouble(double v) {
  // Treat the value as a 64-bit integer value.
  return AddInt64(bit_cast<int64_t, double>(v));
}

size_t ConstantArea::AddFloat(float v) {
  // Treat the value as a 32-bit integer value.
  return AddInt32(bit_cast<int32_t, float>(v));
}

}  // namespace x86_64
}  // namespace art