path: root/js/src/jit/x64/Assembler-x64.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef jit_x64_Assembler_x64_h
#define jit_x64_Assembler_x64_h

#include <iterator>

#include "jit/JitCode.h"
#include "jit/shared/Assembler-shared.h"

namespace js {
namespace jit {

static constexpr Register rax{X86Encoding::rax};
static constexpr Register rbx{X86Encoding::rbx};
static constexpr Register rcx{X86Encoding::rcx};
static constexpr Register rdx{X86Encoding::rdx};
static constexpr Register rsi{X86Encoding::rsi};
static constexpr Register rdi{X86Encoding::rdi};
static constexpr Register rbp{X86Encoding::rbp};
static constexpr Register r8{X86Encoding::r8};
static constexpr Register r9{X86Encoding::r9};
static constexpr Register r10{X86Encoding::r10};
static constexpr Register r11{X86Encoding::r11};
static constexpr Register r12{X86Encoding::r12};
static constexpr Register r13{X86Encoding::r13};
static constexpr Register r14{X86Encoding::r14};
static constexpr Register r15{X86Encoding::r15};
static constexpr Register rsp{X86Encoding::rsp};

static constexpr FloatRegister xmm0 =
    FloatRegister(X86Encoding::xmm0, FloatRegisters::Double);
static constexpr FloatRegister xmm1 =
    FloatRegister(X86Encoding::xmm1, FloatRegisters::Double);
static constexpr FloatRegister xmm2 =
    FloatRegister(X86Encoding::xmm2, FloatRegisters::Double);
static constexpr FloatRegister xmm3 =
    FloatRegister(X86Encoding::xmm3, FloatRegisters::Double);
static constexpr FloatRegister xmm4 =
    FloatRegister(X86Encoding::xmm4, FloatRegisters::Double);
static constexpr FloatRegister xmm5 =
    FloatRegister(X86Encoding::xmm5, FloatRegisters::Double);
static constexpr FloatRegister xmm6 =
    FloatRegister(X86Encoding::xmm6, FloatRegisters::Double);
static constexpr FloatRegister xmm7 =
    FloatRegister(X86Encoding::xmm7, FloatRegisters::Double);
static constexpr FloatRegister xmm8 =
    FloatRegister(X86Encoding::xmm8, FloatRegisters::Double);
static constexpr FloatRegister xmm9 =
    FloatRegister(X86Encoding::xmm9, FloatRegisters::Double);
static constexpr FloatRegister xmm10 =
    FloatRegister(X86Encoding::xmm10, FloatRegisters::Double);
static constexpr FloatRegister xmm11 =
    FloatRegister(X86Encoding::xmm11, FloatRegisters::Double);
static constexpr FloatRegister xmm12 =
    FloatRegister(X86Encoding::xmm12, FloatRegisters::Double);
static constexpr FloatRegister xmm13 =
    FloatRegister(X86Encoding::xmm13, FloatRegisters::Double);
static constexpr FloatRegister xmm14 =
    FloatRegister(X86Encoding::xmm14, FloatRegisters::Double);
static constexpr FloatRegister xmm15 =
    FloatRegister(X86Encoding::xmm15, FloatRegisters::Double);

// Vector registers fixed for use with some instructions, e.g. PBLENDVB.
static constexpr FloatRegister vmm0 =
    FloatRegister(X86Encoding::xmm0, FloatRegisters::Simd128);

// X86-common synonyms.
static constexpr Register eax = rax;
static constexpr Register ebx = rbx;
static constexpr Register ecx = rcx;
static constexpr Register edx = rdx;
static constexpr Register esi = rsi;
static constexpr Register edi = rdi;
static constexpr Register ebp = rbp;
static constexpr Register esp = rsp;

static constexpr Register InvalidReg{X86Encoding::invalid_reg};
static constexpr FloatRegister InvalidFloatReg = FloatRegister();

static constexpr Register StackPointer = rsp;
static constexpr Register FramePointer = rbp;
static constexpr Register JSReturnReg = rcx;
// Avoid, except for assertions.
static constexpr Register JSReturnReg_Type = JSReturnReg;
static constexpr Register JSReturnReg_Data = JSReturnReg;

static constexpr Register ScratchReg = r11;

// Helper class for ScratchRegister usage. Asserts that only one piece
// of code thinks it has exclusive ownership of the scratch register.
struct ScratchRegisterScope : public AutoRegisterScope {
  explicit ScratchRegisterScope(MacroAssembler& masm)
      : AutoRegisterScope(masm, ScratchReg) {}
};

static constexpr Register ReturnReg = rax;
static constexpr Register HeapReg = r15;
static constexpr Register64 ReturnReg64(rax);
static constexpr FloatRegister ReturnFloat32Reg =
    FloatRegister(X86Encoding::xmm0, FloatRegisters::Single);
static constexpr FloatRegister ReturnDoubleReg =
    FloatRegister(X86Encoding::xmm0, FloatRegisters::Double);
static constexpr FloatRegister ReturnSimd128Reg =
    FloatRegister(X86Encoding::xmm0, FloatRegisters::Simd128);
static constexpr FloatRegister ScratchFloat32Reg_ =
    FloatRegister(X86Encoding::xmm15, FloatRegisters::Single);
static constexpr FloatRegister ScratchDoubleReg_ =
    FloatRegister(X86Encoding::xmm15, FloatRegisters::Double);
static constexpr FloatRegister ScratchSimd128Reg =
    FloatRegister(X86Encoding::xmm15, FloatRegisters::Simd128);

// Avoid rbp, which is the FramePointer, which is unavailable in some modes.
static constexpr Register CallTempReg0 = rax;
static constexpr Register CallTempReg1 = rdi;
static constexpr Register CallTempReg2 = rbx;
static constexpr Register CallTempReg3 = rcx;
static constexpr Register CallTempReg4 = rsi;
static constexpr Register CallTempReg5 = rdx;

// Different argument registers for WIN64
#if defined(_WIN64)
static constexpr Register IntArgReg0 = rcx;
static constexpr Register IntArgReg1 = rdx;
static constexpr Register IntArgReg2 = r8;
static constexpr Register IntArgReg3 = r9;
static constexpr uint32_t NumIntArgRegs = 4;
static constexpr Register IntArgRegs[NumIntArgRegs] = {rcx, rdx, r8, r9};

static constexpr Register CallTempNonArgRegs[] = {rax, rdi, rbx, rsi};
static constexpr uint32_t NumCallTempNonArgRegs = std::size(CallTempNonArgRegs);

static constexpr FloatRegister FloatArgReg0 = xmm0;
static constexpr FloatRegister FloatArgReg1 = xmm1;
static constexpr FloatRegister FloatArgReg2 = xmm2;
static constexpr FloatRegister FloatArgReg3 = xmm3;
static constexpr uint32_t NumFloatArgRegs = 4;
static constexpr FloatRegister FloatArgRegs[NumFloatArgRegs] = {xmm0, xmm1,
                                                                xmm2, xmm3};
#else
static constexpr Register IntArgReg0 = rdi;
static constexpr Register IntArgReg1 = rsi;
static constexpr Register IntArgReg2 = rdx;
static constexpr Register IntArgReg3 = rcx;
static constexpr Register IntArgReg4 = r8;
static constexpr Register IntArgReg5 = r9;
static constexpr uint32_t NumIntArgRegs = 6;
static constexpr Register IntArgRegs[NumIntArgRegs] = {rdi, rsi, rdx,
                                                       rcx, r8,  r9};

static constexpr Register CallTempNonArgRegs[] = {rax, rbx};
static constexpr uint32_t NumCallTempNonArgRegs = std::size(CallTempNonArgRegs);

static constexpr FloatRegister FloatArgReg0 = xmm0;
static constexpr FloatRegister FloatArgReg1 = xmm1;
static constexpr FloatRegister FloatArgReg2 = xmm2;
static constexpr FloatRegister FloatArgReg3 = xmm3;
static constexpr FloatRegister FloatArgReg4 = xmm4;
static constexpr FloatRegister FloatArgReg5 = xmm5;
static constexpr FloatRegister FloatArgReg6 = xmm6;
static constexpr FloatRegister FloatArgReg7 = xmm7;
static constexpr uint32_t NumFloatArgRegs = 8;
static constexpr FloatRegister FloatArgRegs[NumFloatArgRegs] = {
    xmm0, xmm1, xmm2, xmm3, xmm4, xmm5, xmm6, xmm7};
#endif

// Registers used by RegExpMatcher and RegExpExecMatch stubs (do not use
// JSReturnOperand).
static constexpr Register RegExpMatcherRegExpReg = CallTempReg0;
static constexpr Register RegExpMatcherStringReg = CallTempReg1;
static constexpr Register RegExpMatcherLastIndexReg = CallTempReg2;

// Registers used by RegExpExecTest stub (do not use ReturnReg).
static constexpr Register RegExpExecTestRegExpReg = CallTempReg1;
static constexpr Register RegExpExecTestStringReg = CallTempReg2;

// Registers used by RegExpSearcher stub (do not use ReturnReg).
static constexpr Register RegExpSearcherRegExpReg = CallTempReg1;
static constexpr Register RegExpSearcherStringReg = CallTempReg2;
static constexpr Register RegExpSearcherLastIndexReg = CallTempReg3;

class ABIArgGenerator {
#if defined(XP_WIN)
  unsigned regIndex_;
#else
  unsigned intRegIndex_;
  unsigned floatRegIndex_;
#endif
  uint32_t stackOffset_;
  ABIArg current_;

 public:
  ABIArgGenerator();
  ABIArg next(MIRType argType);
  ABIArg& current() { return current_; }
  uint32_t stackBytesConsumedSoFar() const { return stackOffset_; }
  void increaseStackOffset(uint32_t bytes) { stackOffset_ += bytes; }
};

// These registers may be volatile or nonvolatile.
// Avoid r11, which is the MacroAssembler's ScratchReg.
static constexpr Register ABINonArgReg0 = rax;
static constexpr Register ABINonArgReg1 = rbx;
static constexpr Register ABINonArgReg2 = r10;
static constexpr Register ABINonArgReg3 = r12;

// This register may be volatile or nonvolatile. Avoid xmm15 which is the
// ScratchDoubleReg.
static constexpr FloatRegister ABINonArgDoubleReg =
    FloatRegister(X86Encoding::xmm8, FloatRegisters::Double);

// These registers may be volatile or nonvolatile.
// Note: these three registers are all guaranteed to be different
static constexpr Register ABINonArgReturnReg0 = r10;
static constexpr Register ABINonArgReturnReg1 = r12;
static constexpr Register ABINonVolatileReg = r13;

// This register is guaranteed to be clobberable during the prologue and
// epilogue of an ABI call which must preserve both ABI argument, return
// and non-volatile registers.
static constexpr Register ABINonArgReturnVolatileReg = r10;

// Instance pointer argument register for WebAssembly functions. This must not
// alias any other register used for passing function arguments or return
// values. Preserved by WebAssembly functions.
static constexpr Register InstanceReg = r14;

// Registers used for asm.js/wasm table calls. These registers must be disjoint
// from the ABI argument registers, InstanceReg and each other.
static constexpr Register WasmTableCallScratchReg0 = ABINonArgReg0;
static constexpr Register WasmTableCallScratchReg1 = ABINonArgReg1;
static constexpr Register WasmTableCallSigReg = ABINonArgReg2;
static constexpr Register WasmTableCallIndexReg = ABINonArgReg3;

// Registers used for ref calls.
static constexpr Register WasmCallRefCallScratchReg0 = ABINonArgReg0;
static constexpr Register WasmCallRefCallScratchReg1 = ABINonArgReg1;
static constexpr Register WasmCallRefReg = ABINonArgReg3;

// Registers used for wasm tail calls operations.
static constexpr Register WasmTailCallInstanceScratchReg = ABINonArgReg1;
static constexpr Register WasmTailCallRAScratchReg = ABINonArgReg2;
static constexpr Register WasmTailCallFPScratchReg = ABINonArgReg3;

// Register used as a scratch along the return path in the fast js -> wasm stub
// code.  This must not overlap ReturnReg, JSReturnOperand, or InstanceReg.
// It must be a volatile register.
static constexpr Register WasmJitEntryReturnScratch = rbx;

static constexpr Register OsrFrameReg = IntArgReg3;

static constexpr Register PreBarrierReg = rdx;

static constexpr Register InterpreterPCReg = r14;

static constexpr uint32_t ABIStackAlignment = 16;
static constexpr uint32_t CodeAlignment = 16;
static constexpr uint32_t JitStackAlignment = 16;

static constexpr uint32_t JitStackValueAlignment =
    JitStackAlignment / sizeof(Value);
static_assert(JitStackAlignment % sizeof(Value) == 0 &&
                  JitStackValueAlignment >= 1,
              "Stack alignment should be a non-zero multiple of sizeof(Value)");

static constexpr uint32_t SimdMemoryAlignment = 16;

static_assert(CodeAlignment % SimdMemoryAlignment == 0,
              "Code alignment should be larger than any of the alignments "
              "which are used for "
              "the constant sections of the code buffer.  Thus it should be "
              "larger than the "
              "alignment for SIMD constants.");

static_assert(JitStackAlignment % SimdMemoryAlignment == 0,
              "Stack alignment should be larger than any of the alignments "
              "which are used for "
              "spilled values.  Thus it should be larger than the alignment "
              "for SIMD accesses.");

static constexpr uint32_t WasmStackAlignment = SimdMemoryAlignment;
static constexpr uint32_t WasmTrapInstructionLength = 2;

// See comments in wasm::GenerateFunctionPrologue.  The difference between these
// is the size of the largest callable prologue on the platform.
static constexpr uint32_t WasmCheckedCallEntryOffset = 0u;

static constexpr Scale ScalePointer = TimesEight;

}  // namespace jit
}  // namespace js

#include "jit/x86-shared/Assembler-x86-shared.h"

namespace js {
namespace jit {

// Return operand from a JS -> JS call.
static constexpr ValueOperand JSReturnOperand = ValueOperand(JSReturnReg);

class Assembler : public AssemblerX86Shared {
  // x64 jumps may need extra bits of relocation, because a jump may extend
  // beyond the signed 32-bit range. To account for this we add an extended
  // jump table at the bottom of the instruction stream, and if a jump
  // overflows its range, it will redirect here.
  //
  // Each entry in this table is a jmp [rip], followed by a ud2 to hint to the
  // hardware branch predictor that there is no fallthrough, followed by the
  // eight bytes containing an immediate address. This comes out to 16 bytes.
  //    +1 byte for opcode
  //    +1 byte for mod r/m
  //    +4 bytes for rip-relative offset (2)
  //    +2 bytes for ud2 instruction
  //    +8 bytes for 64-bit address
  //
  static const uint32_t SizeOfExtendedJump = 1 + 1 + 4 + 2 + 8;
  static const uint32_t SizeOfJumpTableEntry = 16;

  // Two kinds of jumps on x64:
  //
  // * codeJumps_ tracks jumps with target within the executable code region
  //   for the process. These jumps don't need entries in the extended jump
  //   table because source and target must be within 2 GB of each other.
  //
  // * extendedJumps_ tracks jumps with target outside the executable code
  //   region. These jumps need entries in the extended jump table described
  //   above.
  using PendingJumpVector = Vector<RelativePatch, 8, SystemAllocPolicy>;
  PendingJumpVector codeJumps_;
  PendingJumpVector extendedJumps_;

  uint32_t extendedJumpTable_;

  static JitCode* CodeFromJump(JitCode* code, uint8_t* jump);

 private:
  void addPendingJump(JmpSrc src, ImmPtr target, RelocationKind reloc);

 public:
  using AssemblerX86Shared::j;
  using AssemblerX86Shared::jmp;
  using AssemblerX86Shared::pop;
  using AssemblerX86Shared::push;
  using AssemblerX86Shared::vmovq;

  Assembler() : extendedJumpTable_(0) {}

  static void TraceJumpRelocations(JSTracer* trc, JitCode* code,
                                   CompactBufferReader& reader);

  // The buffer is about to be linked, make sure any constant pools or excess
  // bookkeeping has been flushed to the instruction stream.
  void finish();

  // Copy the assembly code to the given buffer, and perform any pending
  // relocations relying on the target address.
  void executableCopy(uint8_t* buffer);

  void assertNoGCThings() const {
#ifdef DEBUG
    MOZ_ASSERT(dataRelocations_.length() == 0);
    for (auto& j : codeJumps_) {
      MOZ_ASSERT(j.kind == RelocationKind::HARDCODED);
    }
    for (auto& j : extendedJumps_) {
      MOZ_ASSERT(j.kind == RelocationKind::HARDCODED);
    }
#endif
  }

  // Actual assembly emitting functions.

  void push(const ImmGCPtr ptr) {
    movq(ptr, ScratchReg);
    push(ScratchReg);
  }
  void push(const ImmWord ptr) {
    // We often end up with ImmWords that actually fit into int32.
    // Be aware of the sign extension behavior.
    if (ptr.value <= INT32_MAX) {
      push(Imm32(ptr.value));
    } else {
      movq(ptr, ScratchReg);
      push(ScratchReg);
    }
  }
  void push(ImmPtr imm) { push(ImmWord(uintptr_t(imm.value))); }
  void push(FloatRegister src) {
    subq(Imm32(sizeof(double)), StackPointer);
    vmovsd(src, Address(StackPointer, 0));
  }
  CodeOffset pushWithPatch(ImmWord word) {
    CodeOffset label = movWithPatch(word, ScratchReg);
    push(ScratchReg);
    return label;
  }

  void pop(FloatRegister src) {
    vmovsd(Address(StackPointer, 0), src);
    addq(Imm32(sizeof(double)), StackPointer);
  }

  CodeOffset movWithPatch(ImmWord word, Register dest) {
    masm.movq_i64r(word.value, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movWithPatch(ImmPtr imm, Register dest) {
    return movWithPatch(ImmWord(uintptr_t(imm.value)), dest);
  }

  // This is for patching during code generation, not after.
  void patchAddq(CodeOffset offset, int32_t n) {
    unsigned char* code = masm.data();
    X86Encoding::SetInt32(code + offset.offset(), n);
  }

  // Load an ImmWord value into a register. Note that this instruction will
  // attempt to optimize its immediate field size. When a full 64-bit
  // immediate is needed for a relocation, use movWithPatch.
  void movq(ImmWord word, Register dest) {
    // Load a 64-bit immediate into a register. If the value falls into
    // certain ranges, we can use specialized instructions which have
    // smaller encodings.
    if (word.value <= UINT32_MAX) {
      // movl has a 32-bit unsigned (effectively) immediate field.
      masm.movl_i32r((uint32_t)word.value, dest.encoding());
    } else if ((intptr_t)word.value >= INT32_MIN &&
               (intptr_t)word.value <= INT32_MAX) {
      // movq has a 32-bit signed immediate field.
      masm.movq_i32r((int32_t)(intptr_t)word.value, dest.encoding());
    } else {
      // Otherwise use movabs.
      masm.movq_i64r(word.value, dest.encoding());
    }
  }
  void movq(ImmPtr imm, Register dest) {
    movq(ImmWord(uintptr_t(imm.value)), dest);
  }
  void movq(ImmGCPtr ptr, Register dest) {
    masm.movq_i64r(uintptr_t(ptr.value), dest.encoding());
    writeDataRelocation(ptr);
  }
  void movq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.movq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.movq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.movq_mr(src.disp(), src.base(), src.index(), src.scale(),
                     dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movq_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void movq(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.movq_rr(src.encoding(), dest.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.movq_rm(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_SCALE:
        masm.movq_rm(src.encoding(), dest.disp(), dest.base(), dest.index(),
                     dest.scale());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movq_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void movq(Imm32 imm32, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.movl_i32r(imm32.value, dest.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.movq_i32m(imm32.value, dest.disp(), dest.base());
        break;
      case Operand::MEM_SCALE:
        masm.movq_i32m(imm32.value, dest.disp(), dest.base(), dest.index(),
                       dest.scale());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movq_i32m(imm32.value, dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void vmovq(Register src, FloatRegister dest) {
    masm.vmovq_rr(src.encoding(), dest.encoding());
  }
  void vmovq(FloatRegister src, Register dest) {
    masm.vmovq_rr(src.encoding(), dest.encoding());
  }
  void movq(Register src, Register dest) {
    masm.movq_rr(src.encoding(), dest.encoding());
  }

  void cmovCCq(Condition cond, const Operand& src, Register dest) {
    X86Encoding::Condition cc = static_cast<X86Encoding::Condition>(cond);
    switch (src.kind()) {
      case Operand::REG:
        masm.cmovCCq_rr(cc, src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.cmovCCq_mr(cc, src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.cmovCCq_mr(cc, src.disp(), src.base(), src.index(), src.scale(),
                        dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void cmovCCq(Condition cond, Register src, Register dest) {
    X86Encoding::Condition cc = static_cast<X86Encoding::Condition>(cond);
    masm.cmovCCq_rr(cc, src.encoding(), dest.encoding());
  }

  void cmovzq(const Operand& src, Register dest) {
    cmovCCq(Condition::Zero, src, dest);
  }
  void cmovnzq(const Operand& src, Register dest) {
    cmovCCq(Condition::NonZero, src, dest);
  }

  template <typename T>
  void lock_addq(T src, const Operand& op) {
    masm.prefix_lock();
    addq(src, op);
  }
  template <typename T>
  void lock_subq(T src, const Operand& op) {
    masm.prefix_lock();
    subq(src, op);
  }
  template <typename T>
  void lock_andq(T src, const Operand& op) {
    masm.prefix_lock();
    andq(src, op);
  }
  template <typename T>
  void lock_orq(T src, const Operand& op) {
    masm.prefix_lock();
    orq(src, op);
  }
  template <typename T>
  void lock_xorq(T src, const Operand& op) {
    masm.prefix_lock();
    xorq(src, op);
  }

  void lock_cmpxchgq(Register src, const Operand& mem) {
    masm.prefix_lock();
    switch (mem.kind()) {
      case Operand::MEM_REG_DISP:
        masm.cmpxchgq(src.encoding(), mem.disp(), mem.base());
        break;
      case Operand::MEM_SCALE:
        masm.cmpxchgq(src.encoding(), mem.disp(), mem.base(), mem.index(),
                      mem.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void xchgq(Register src, Register dest) {
    masm.xchgq_rr(src.encoding(), dest.encoding());
  }

  void xchgq(Register src, const Operand& mem) {
    switch (mem.kind()) {
      case Operand::MEM_REG_DISP:
        masm.xchgq_rm(src.encoding(), mem.disp(), mem.base());
        break;
      case Operand::MEM_SCALE:
        masm.xchgq_rm(src.encoding(), mem.disp(), mem.base(), mem.index(),
                      mem.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void lock_xaddq(Register srcdest, const Operand& mem) {
    switch (mem.kind()) {
      case Operand::MEM_REG_DISP:
        masm.lock_xaddq_rm(srcdest.encoding(), mem.disp(), mem.base());
        break;
      case Operand::MEM_SCALE:
        masm.lock_xaddq_rm(srcdest.encoding(), mem.disp(), mem.base(),
                           mem.index(), mem.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void movsbq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.movsbq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.movsbq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.movsbq_mr(src.disp(), src.base(), src.index(), src.scale(),
                       dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void movzbq(const Operand& src, Register dest) {
    // movzbl zero-extends to 64 bits and is one byte smaller, so use that
    // instead.
    movzbl(src, dest);
  }

  void movswq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.movswq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.movswq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.movswq_mr(src.disp(), src.base(), src.index(), src.scale(),
                       dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void movzwq(const Operand& src, Register dest) {
    // movzwl zero-extends to 64 bits and is one byte smaller, so use that
    // instead.
    movzwl(src, dest);
  }

  void movslq(Register src, Register dest) {
    masm.movslq_rr(src.encoding(), dest.encoding());
  }
  void movslq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.movslq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.movslq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.movslq_mr(src.disp(), src.base(), src.index(), src.scale(),
                       dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void andq(Register src, Register dest) {
    masm.andq_rr(src.encoding(), dest.encoding());
  }
  void andq(Imm32 imm, Register dest) {
    masm.andq_ir(imm.value, dest.encoding());
  }
  void andq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.andq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.andq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.andq_mr(src.disp(), src.base(), src.index(), src.scale(),
                     dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.andq_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void andq(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.andq_rr(src.encoding(), dest.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.andq_rm(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_SCALE:
        masm.andq_rm(src.encoding(), dest.disp(), dest.base(), dest.index(),
                     dest.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void addq(Imm32 imm, Register dest) {
    masm.addq_ir(imm.value, dest.encoding());
  }
  CodeOffset addqWithPatch(Imm32 imm, Register dest) {
    masm.addq_i32r(imm.value, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  void addq(Imm32 imm, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.addq_ir(imm.value, dest.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.addq_im(imm.value, dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.addq_im(imm.value, dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void addq(Register src, Register dest) {
    masm.addq_rr(src.encoding(), dest.encoding());
  }
  void addq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.addq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.addq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.addq_mr(src.address(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.addq_mr(src.disp(), src.base(), src.index(), src.scale(),
                     dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void addq(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.addq_rr(src.encoding(), dest.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.addq_rm(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_SCALE:
        masm.addq_rm(src.encoding(), dest.disp(), dest.base(), dest.index(),
                     dest.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void subq(Imm32 imm, Register dest) {
    masm.subq_ir(imm.value, dest.encoding());
  }
  void subq(Register src, Register dest) {
    masm.subq_rr(src.encoding(), dest.encoding());
  }
  void subq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.subq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.subq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.subq_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void subq(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.subq_rr(src.encoding(), dest.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.subq_rm(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_SCALE:
        masm.subq_rm(src.encoding(), dest.disp(), dest.base(), dest.index(),
                     dest.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void shlq(Imm32 imm, Register dest) {
    masm.shlq_ir(imm.value, dest.encoding());
  }
  void shrq(Imm32 imm, Register dest) {
    masm.shrq_ir(imm.value, dest.encoding());
  }
  void sarq(Imm32 imm, Register dest) {
    masm.sarq_ir(imm.value, dest.encoding());
  }
  void shlq_cl(Register dest) { masm.shlq_CLr(dest.encoding()); }
  void shrq_cl(Register dest) { masm.shrq_CLr(dest.encoding()); }
  void sarq_cl(Register dest) { masm.sarq_CLr(dest.encoding()); }
  void sarxq(Register src, Register shift, Register dest) {
    MOZ_ASSERT(HasBMI2());
    masm.sarxq_rrr(src.encoding(), shift.encoding(), dest.encoding());
  }
  void shlxq(Register src, Register shift, Register dest) {
    MOZ_ASSERT(HasBMI2());
    masm.shlxq_rrr(src.encoding(), shift.encoding(), dest.encoding());
  }
  void shrxq(Register src, Register shift, Register dest) {
    MOZ_ASSERT(HasBMI2());
    masm.shrxq_rrr(src.encoding(), shift.encoding(), dest.encoding());
  }
  void rolq(Imm32 imm, Register dest) {
    masm.rolq_ir(imm.value, dest.encoding());
  }
  void rolq_cl(Register dest) { masm.rolq_CLr(dest.encoding()); }
  void rorq(Imm32 imm, Register dest) {
    masm.rorq_ir(imm.value, dest.encoding());
  }
  void rorq_cl(Register dest) { masm.rorq_CLr(dest.encoding()); }
  void orq(Imm32 imm, Register dest) {
    masm.orq_ir(imm.value, dest.encoding());
  }
  void orq(Register src, Register dest) {
    masm.orq_rr(src.encoding(), dest.encoding());
  }
  void orq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.orq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.orq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.orq_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void orq(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.orq_rr(src.encoding(), dest.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.orq_rm(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_SCALE:
        masm.orq_rm(src.encoding(), dest.disp(), dest.base(), dest.index(),
                    dest.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void xorq(Register src, Register dest) {
    masm.xorq_rr(src.encoding(), dest.encoding());
  }
  void xorq(Imm32 imm, Register dest) {
    masm.xorq_ir(imm.value, dest.encoding());
  }
  void xorq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.xorq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.xorq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.xorq_mr(src.disp(), src.base(), src.index(), src.scale(),
                     dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.xorq_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void xorq(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.xorq_rr(src.encoding(), dest.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.xorq_rm(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_SCALE:
        masm.xorq_rm(src.encoding(), dest.disp(), dest.base(), dest.index(),
                     dest.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void bsrq(const Register& src, const Register& dest) {
    masm.bsrq_rr(src.encoding(), dest.encoding());
  }
  void bsfq(const Register& src, const Register& dest) {
    masm.bsfq_rr(src.encoding(), dest.encoding());
  }
  void bswapq(const Register& reg) { masm.bswapq_r(reg.encoding()); }
  void lzcntq(const Register& src, const Register& dest) {
    masm.lzcntq_rr(src.encoding(), dest.encoding());
  }
  void tzcntq(const Register& src, const Register& dest) {
    masm.tzcntq_rr(src.encoding(), dest.encoding());
  }
  void popcntq(const Register& src, const Register& dest) {
    masm.popcntq_rr(src.encoding(), dest.encoding());
  }

  void imulq(Imm32 imm, Register src, Register dest) {
    masm.imulq_ir(imm.value, src.encoding(), dest.encoding());
  }
  void imulq(Register src, Register dest) {
    masm.imulq_rr(src.encoding(), dest.encoding());
  }
  void imulq(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::REG:
        masm.imulq_rr(src.reg(), dest.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.imulq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        MOZ_CRASH("NYI");
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void cqo() { masm.cqo(); }
  void idivq(Register divisor) { masm.idivq_r(divisor.encoding()); }
  void udivq(Register divisor) { masm.divq_r(divisor.encoding()); }

  void vcvtsi2sdq(Register src, FloatRegister dest) {
    masm.vcvtsi2sdq_rr(src.encoding(), dest.encoding());
  }

  void vpextrq(unsigned lane, FloatRegister src, Register dest) {
    MOZ_ASSERT(HasSSE41());
    masm.vpextrq_irr(lane, src.encoding(), dest.encoding());
  }

  void vpinsrq(unsigned lane, Register src1, FloatRegister src0,
               FloatRegister dest) {
    MOZ_ASSERT(HasSSE41());
    masm.vpinsrq_irr(lane, src1.encoding(), src0.encoding(), dest.encoding());
  }

  void negq(Register reg) { masm.negq_r(reg.encoding()); }

  void notq(Register reg) { masm.notq_r(reg.encoding()); }

  void mov(ImmWord word, Register dest) {
    // Use xor for setting registers to zero, as it is specially optimized
    // for this purpose on modern hardware. Note that it does clobber FLAGS
    // though. Use xorl instead of xorq since they are functionally
    // equivalent (32-bit instructions zero-extend their results to 64 bits)
    // and xorl has a smaller encoding.
    if (word.value == 0) {
      xorl(dest, dest);
    } else {
      movq(word, dest);
    }
  }
  void mov(ImmPtr imm, Register dest) { movq(imm, dest); }
  void mov(wasm::SymbolicAddress imm, Register dest) {
    masm.movq_i64r(-1, dest.encoding());
    append(wasm::SymbolicAccess(CodeOffset(masm.currentOffset()), imm));
  }
  void mov(const Operand& src, Register dest) { movq(src, dest); }
  void mov(Register src, const Operand& dest) { movq(src, dest); }
  void mov(Imm32 imm32, const Operand& dest) { movq(imm32, dest); }
  void mov(Register src, Register dest) { movq(src, dest); }
  void mov(CodeLabel* label, Register dest) {
    masm.movq_i64r(/* placeholder */ 0, dest.encoding());
    label->patchAt()->bind(masm.size());
  }
  void xchg(Register src, Register dest) { xchgq(src, dest); }

  void lea(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.leaq_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.leaq_mr(src.disp(), src.base(), src.index(), src.scale(),
                     dest.encoding());
        break;
      default:
        MOZ_CRASH("unexepcted operand kind");
    }
  }

  void cmovz32(const Operand& src, Register dest) { return cmovzl(src, dest); }
  void cmovzPtr(const Operand& src, Register dest) { return cmovzq(src, dest); }

  CodeOffset loadRipRelativeInt32(Register dest) {
    return CodeOffset(masm.movl_ripr(dest.encoding()).offset());
  }
  CodeOffset loadRipRelativeInt64(Register dest) {
    return CodeOffset(masm.movq_ripr(dest.encoding()).offset());
  }
  CodeOffset loadRipRelativeDouble(FloatRegister dest) {
    return CodeOffset(masm.vmovsd_ripr(dest.encoding()).offset());
  }
  CodeOffset loadRipRelativeFloat32(FloatRegister dest) {
    return CodeOffset(masm.vmovss_ripr(dest.encoding()).offset());
  }
  CodeOffset loadRipRelativeInt32x4(FloatRegister dest) {
    return CodeOffset(masm.vmovdqa_ripr(dest.encoding()).offset());
  }
  CodeOffset loadRipRelativeFloat32x4(FloatRegister dest) {
    return CodeOffset(masm.vmovaps_ripr(dest.encoding()).offset());
  }
  CodeOffset leaRipRelative(Register dest) {
    return CodeOffset(masm.leaq_rip(dest.encoding()).offset());
  }

  void cmpq(Register rhs, Register lhs) {
    masm.cmpq_rr(rhs.encoding(), lhs.encoding());
  }
  void cmpq(Register rhs, const Operand& lhs) {
    switch (lhs.kind()) {
      case Operand::REG:
        masm.cmpq_rr(rhs.encoding(), lhs.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.cmpq_rm(rhs.encoding(), lhs.disp(), lhs.base());
        break;
      case Operand::MEM_SCALE:
        masm.cmpq_rm(rhs.encoding(), lhs.disp(), lhs.base(), lhs.index(),
                     lhs.scale());
        break;
      case Operand::MEM_ADDRESS32:
        masm.cmpq_rm(rhs.encoding(), lhs.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void cmpq(Imm32 rhs, Register lhs) {
    masm.cmpq_ir(rhs.value, lhs.encoding());
  }
  void cmpq(Imm32 rhs, const Operand& lhs) {
    switch (lhs.kind()) {
      case Operand::REG:
        masm.cmpq_ir(rhs.value, lhs.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.cmpq_im(rhs.value, lhs.disp(), lhs.base());
        break;
      case Operand::MEM_SCALE:
        masm.cmpq_im(rhs.value, lhs.disp(), lhs.base(), lhs.index(),
                     lhs.scale());
        break;
      case Operand::MEM_ADDRESS32:
        masm.cmpq_im(rhs.value, lhs.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void cmpq(const Operand& rhs, Register lhs) {
    switch (rhs.kind()) {
      case Operand::REG:
        masm.cmpq_rr(rhs.reg(), lhs.encoding());
        break;
      case Operand::MEM_REG_DISP:
        masm.cmpq_mr(rhs.disp(), rhs.base(), lhs.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void testq(Imm32 rhs, Register lhs) {
    masm.testq_ir(rhs.value, lhs.encoding());
  }
  void testq(Register rhs, Register lhs) {
    masm.testq_rr(rhs.encoding(), lhs.encoding());
  }
  void testq(Imm32 rhs, const Operand& lhs) {
    switch (lhs.kind()) {
      case Operand::REG:
        masm.testq_ir(rhs.value, lhs.reg());
        break;
      case Operand::MEM_REG_DISP:
        masm.testq_i32m(rhs.value, lhs.disp(), lhs.base());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
        break;
    }
  }

  void jmp(ImmPtr target, RelocationKind reloc = RelocationKind::HARDCODED) {
    MOZ_ASSERT(hasCreator());
    JmpSrc src = masm.jmp();
    addPendingJump(src, target, reloc);
  }
  void j(Condition cond, ImmPtr target,
         RelocationKind reloc = RelocationKind::HARDCODED) {
    JmpSrc src = masm.jCC(static_cast<X86Encoding::Condition>(cond));
    addPendingJump(src, target, reloc);
  }

  void jmp(JitCode* target) {
    jmp(ImmPtr(target->raw()), RelocationKind::JITCODE);
  }
  void j(Condition cond, JitCode* target) {
    j(cond, ImmPtr(target->raw()), RelocationKind::JITCODE);
  }
  void call(JitCode* target) {
    JmpSrc src = masm.call();
    addPendingJump(src, ImmPtr(target->raw()), RelocationKind::JITCODE);
  }
  void call(ImmWord target) { call(ImmPtr((void*)target.value)); }
  void call(ImmPtr target) {
    JmpSrc src = masm.call();
    addPendingJump(src, target, RelocationKind::HARDCODED);
  }

  // Emit a CALL or CMP (nop) instruction. ToggleCall can be used to patch
  // this instruction.
  CodeOffset toggledCall(JitCode* target, bool enabled) {
    CodeOffset offset(size());
    JmpSrc src = enabled ? masm.call() : masm.cmp_eax();
    addPendingJump(src, ImmPtr(target->raw()), RelocationKind::JITCODE);
    MOZ_ASSERT_IF(!oom(), size() - offset.offset() == ToggledCallSize(nullptr));
    return offset;
  }

  static size_t ToggledCallSize(uint8_t* code) {
    // Size of a call instruction.
    return 5;
  }

  // Do not mask shared implementations.
  using AssemblerX86Shared::call;

  void vcvttsd2sq(FloatRegister src, Register dest) {
    masm.vcvttsd2sq_rr(src.encoding(), dest.encoding());
  }
  void vcvttss2sq(FloatRegister src, Register dest) {
    masm.vcvttss2sq_rr(src.encoding(), dest.encoding());
  }
  void vcvtsq2sd(Register src1, FloatRegister src0, FloatRegister dest) {
    masm.vcvtsq2sd_rr(src1.encoding(), src0.encoding(), dest.encoding());
  }
  void vcvtsq2ss(Register src1, FloatRegister src0, FloatRegister dest) {
    masm.vcvtsq2ss_rr(src1.encoding(), src0.encoding(), dest.encoding());
  }
};

static inline bool GetIntArgReg(uint32_t intArg, uint32_t floatArg,
                                Register* out) {
#if defined(_WIN64)
  uint32_t arg = intArg + floatArg;
#else
  uint32_t arg = intArg;
#endif
  if (arg >= NumIntArgRegs) {
    return false;
  }
  *out = IntArgRegs[arg];
  return true;
}

// Get a register in which we plan to put a quantity that will be used as an
// integer argument.  This differs from GetIntArgReg in that if we have no more
// actual argument registers to use we will fall back on using whatever
// CallTempReg* don't overlap the argument registers, and only fail once those
// run out too.
static inline bool GetTempRegForIntArg(uint32_t usedIntArgs,
                                       uint32_t usedFloatArgs, Register* out) {
  if (GetIntArgReg(usedIntArgs, usedFloatArgs, out)) {
    return true;
  }
  // Unfortunately, we have to assume things about the point at which
  // GetIntArgReg returns false, because we need to know how many registers it
  // can allocate.
#if defined(_WIN64)
  uint32_t arg = usedIntArgs + usedFloatArgs;
#else
  uint32_t arg = usedIntArgs;
#endif
  arg -= NumIntArgRegs;
  if (arg >= NumCallTempNonArgRegs) {
    return false;
  }
  *out = CallTempNonArgRegs[arg];
  return true;
}

static inline bool GetFloatArgReg(uint32_t intArg, uint32_t floatArg,
                                  FloatRegister* out) {
#if defined(_WIN64)
  uint32_t arg = intArg + floatArg;
#else
  uint32_t arg = floatArg;
#endif
  if (floatArg >= NumFloatArgRegs) {
    return false;
  }
  *out = FloatArgRegs[arg];
  return true;
}

}  // namespace jit
}  // namespace js

#endif /* jit_x64_Assembler_x64_h */