path: root/js/src/jit/x86/Assembler-x86.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_x86_Assembler_x86_h
#define jit_x86_Assembler_x86_h

#include <iterator>

#include "jit/CompactBuffer.h"
#include "jit/JitCode.h"
#include "jit/shared/Assembler-shared.h"
#include "jit/x86-shared/Constants-x86-shared.h"

namespace js {
namespace jit {

static constexpr Register eax{X86Encoding::rax};
static constexpr Register ecx{X86Encoding::rcx};
static constexpr Register edx{X86Encoding::rdx};
static constexpr Register ebx{X86Encoding::rbx};
static constexpr Register esp{X86Encoding::rsp};
static constexpr Register ebp{X86Encoding::rbp};
static constexpr Register esi{X86Encoding::rsi};
static constexpr Register edi{X86Encoding::rdi};

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);

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

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

static constexpr Register JSReturnReg_Type = ecx;
static constexpr Register JSReturnReg_Data = edx;
static constexpr Register StackPointer = esp;
static constexpr Register FramePointer = ebp;
static constexpr Register ReturnReg = eax;
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::xmm7, FloatRegisters::Single);
static constexpr FloatRegister ScratchDoubleReg_ =
    FloatRegister(X86Encoding::xmm7, FloatRegisters::Double);
static constexpr FloatRegister ScratchSimd128Reg =
    FloatRegister(X86Encoding::xmm7, FloatRegisters::Simd128);

// Note, EDX:EAX is the system ABI 64-bit return register, and it is to our
// advantage to keep the SpiderMonkey ABI in sync with the system ABI.
//
// However, using EDX here means that we have to use a register that does not
// have a word or byte part (eg DX/DH/DL) in some other places; notably,
// ABINonArgReturnReg1 is EDI.  If this becomes a problem and ReturnReg64 has to
// be something other than EDX:EAX, then jitted code that calls directly to C++
// will need to shuffle the return value from EDX:EAX into ReturnReg64 directly
// after the call.  See bug 1730161 for discussion and a patch that does that.
static constexpr Register64 ReturnReg64(edx, eax);

// Avoid ebp, which is the FramePointer, which is unavailable in some modes.
static constexpr Register CallTempReg0 = edi;
static constexpr Register CallTempReg1 = eax;
static constexpr Register CallTempReg2 = ebx;
static constexpr Register CallTempReg3 = ecx;
static constexpr Register CallTempReg4 = esi;
static constexpr Register CallTempReg5 = edx;

// We have no arg regs, so our NonArgRegs are just our CallTempReg*
static constexpr Register CallTempNonArgRegs[] = {edi, eax, ebx, ecx, esi, edx};
static constexpr uint32_t NumCallTempNonArgRegs = std::size(CallTempNonArgRegs);

class ABIArgGenerator {
  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.
static constexpr Register ABINonArgReg0 = eax;
static constexpr Register ABINonArgReg1 = ebx;
static constexpr Register ABINonArgReg2 = ecx;
static constexpr Register ABINonArgReg3 = edx;

// This register may be volatile or nonvolatile. Avoid xmm7 which is the
// ScratchDoubleReg_.
static constexpr FloatRegister ABINonArgDoubleReg =
    FloatRegister(X86Encoding::xmm0, FloatRegisters::Double);

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

// 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 = ecx;

// 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 = esi;

// 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 = ebx;

static constexpr Register OsrFrameReg = edx;
static constexpr Register PreBarrierReg = edx;

// Not enough registers for a PC register (R0-R2 use 2 registers each).
static constexpr Register InterpreterPCReg = InvalidReg;

// 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 = CallTempReg0;
static constexpr Register RegExpExecTestStringReg = CallTempReg2;

// Registers used by RegExpSearcher stub (do not use ReturnReg).
static constexpr Register RegExpSearcherRegExpReg = CallTempReg0;
static constexpr Register RegExpSearcherStringReg = CallTempReg2;
static constexpr Register RegExpSearcherLastIndexReg = CallTempReg3;

// GCC stack is aligned on 16 bytes. Ion does not maintain this for internal
// calls. wasm code does.
#if defined(__GNUC__) && !defined(__MINGW32__)
static constexpr uint32_t ABIStackAlignment = 16;
#else
static constexpr uint32_t ABIStackAlignment = 4;
#endif
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.  (We could make
// the tail offset 3, but I have opted for 4 as that results in a better-aligned
// branch target.)
static constexpr uint32_t WasmCheckedCallEntryOffset = 0u;

struct ImmTag : public Imm32 {
  explicit ImmTag(JSValueTag mask) : Imm32(int32_t(mask)) {}
};

struct ImmType : public ImmTag {
  explicit ImmType(JSValueType type) : ImmTag(JSVAL_TYPE_TO_TAG(type)) {}
};

static constexpr Scale ScalePointer = TimesFour;

}  // namespace jit
}  // namespace js

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

namespace js {
namespace jit {

static inline Operand LowWord(const Operand& op) {
  switch (op.kind()) {
    case Operand::MEM_REG_DISP:
      return Operand(LowWord(op.toAddress()));
    case Operand::MEM_SCALE:
      return Operand(LowWord(op.toBaseIndex()));
    default:
      MOZ_CRASH("Invalid operand type");
  }
}

static inline Operand HighWord(const Operand& op) {
  switch (op.kind()) {
    case Operand::MEM_REG_DISP:
      return Operand(HighWord(op.toAddress()));
    case Operand::MEM_SCALE:
      return Operand(HighWord(op.toBaseIndex()));
    default:
      MOZ_CRASH("Invalid operand type");
  }
}

// Return operand from a JS -> JS call.
static constexpr ValueOperand JSReturnOperand{JSReturnReg_Type,
                                              JSReturnReg_Data};

class Assembler : public AssemblerX86Shared {
  Vector<RelativePatch, 8, SystemAllocPolicy> jumps_;

  void addPendingJump(JmpSrc src, ImmPtr target, RelocationKind kind) {
    enoughMemory_ &=
        jumps_.append(RelativePatch(src.offset(), target.value, kind));
    if (kind == RelocationKind::JITCODE) {
      jumpRelocations_.writeUnsigned(src.offset());
    }
  }

 public:
  using AssemblerX86Shared::call;
  using AssemblerX86Shared::cmpl;
  using AssemblerX86Shared::j;
  using AssemblerX86Shared::jmp;
  using AssemblerX86Shared::movl;
  using AssemblerX86Shared::pop;
  using AssemblerX86Shared::push;
  using AssemblerX86Shared::retarget;
  using AssemblerX86Shared::vmovsd;
  using AssemblerX86Shared::vmovss;

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

  // 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 : jumps_) {
      MOZ_ASSERT(j.kind == RelocationKind::HARDCODED);
    }
#endif
  }

  // Actual assembly emitting functions.

  void push(ImmGCPtr ptr) {
    masm.push_i32(int32_t(ptr.value));
    writeDataRelocation(ptr);
  }
  void push(const ImmWord imm) { push(Imm32(imm.value)); }
  void push(const ImmPtr imm) { push(ImmWord(uintptr_t(imm.value))); }
  void push(FloatRegister src) {
    subl(Imm32(sizeof(double)), StackPointer);
    vmovsd(src, Address(StackPointer, 0));
  }

  CodeOffset pushWithPatch(ImmWord word) {
    masm.push_i32(int32_t(word.value));
    return CodeOffset(masm.currentOffset());
  }

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

  CodeOffset movWithPatch(ImmWord word, Register dest) {
    movl(Imm32(word.value), dest);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movWithPatch(ImmPtr imm, Register dest) {
    return movWithPatch(ImmWord(uintptr_t(imm.value)), dest);
  }

  void movl(ImmGCPtr ptr, Register dest) {
    masm.movl_i32r(uintptr_t(ptr.value), dest.encoding());
    writeDataRelocation(ptr);
  }
  void movl(ImmGCPtr ptr, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::REG:
        masm.movl_i32r(uintptr_t(ptr.value), dest.reg());
        writeDataRelocation(ptr);
        break;
      case Operand::MEM_REG_DISP:
        masm.movl_i32m(uintptr_t(ptr.value), dest.disp(), dest.base());
        writeDataRelocation(ptr);
        break;
      case Operand::MEM_SCALE:
        masm.movl_i32m(uintptr_t(ptr.value), dest.disp(), dest.base(),
                       dest.index(), dest.scale());
        writeDataRelocation(ptr);
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void movl(ImmWord imm, Register dest) {
    masm.movl_i32r(imm.value, dest.encoding());
  }
  void movl(ImmPtr imm, Register dest) {
    movl(ImmWord(uintptr_t(imm.value)), dest);
  }
  void mov(ImmWord imm, 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.
    if (imm.value == 0) {
      xorl(dest, dest);
    } else {
      movl(imm, dest);
    }
  }
  void mov(ImmPtr imm, Register dest) {
    mov(ImmWord(uintptr_t(imm.value)), dest);
  }
  void mov(wasm::SymbolicAddress imm, Register dest) {
    masm.movl_i32r(-1, dest.encoding());
    append(wasm::SymbolicAccess(CodeOffset(masm.currentOffset()), imm));
  }
  void mov(const Operand& src, Register dest) { movl(src, dest); }
  void mov(Register src, const Operand& dest) { movl(src, dest); }
  void mov(Imm32 imm, const Operand& dest) { movl(imm, dest); }
  void mov(CodeLabel* label, Register dest) {
    // Put a placeholder value in the instruction stream.
    masm.movl_i32r(0, dest.encoding());
    label->patchAt()->bind(masm.size());
  }
  void mov(Register src, Register dest) { movl(src, dest); }
  void xchg(Register src, Register dest) { xchgl(src, dest); }
  void lea(const Operand& src, Register dest) { return leal(src, dest); }
  void cmovz32(const Operand& src, Register dest) { return cmovzl(src, dest); }
  void cmovzPtr(const Operand& src, Register dest) { return cmovzl(src, dest); }

  void fstp32(const Operand& src) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.fstp32_m(src.disp(), src.base());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void faddp() { masm.faddp(); }

  void cmpl(ImmWord rhs, Register lhs) {
    masm.cmpl_ir(rhs.value, lhs.encoding());
  }
  void cmpl(ImmPtr rhs, Register lhs) {
    cmpl(ImmWord(uintptr_t(rhs.value)), lhs);
  }
  void cmpl(ImmGCPtr rhs, Register lhs) {
    masm.cmpl_i32r(uintptr_t(rhs.value), lhs.encoding());
    writeDataRelocation(rhs);
  }
  void cmpl(Register rhs, Register lhs) {
    masm.cmpl_rr(rhs.encoding(), lhs.encoding());
  }
  void cmpl(ImmGCPtr rhs, const Operand& lhs) {
    switch (lhs.kind()) {
      case Operand::REG:
        masm.cmpl_i32r(uintptr_t(rhs.value), lhs.reg());
        writeDataRelocation(rhs);
        break;
      case Operand::MEM_REG_DISP:
        masm.cmpl_i32m(uintptr_t(rhs.value), lhs.disp(), lhs.base());
        writeDataRelocation(rhs);
        break;
      case Operand::MEM_ADDRESS32:
        masm.cmpl_i32m(uintptr_t(rhs.value), lhs.address());
        writeDataRelocation(rhs);
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  void cmpl(Register rhs, wasm::SymbolicAddress lhs) {
    masm.cmpl_rm_disp32(rhs.encoding(), (void*)-1);
    append(wasm::SymbolicAccess(CodeOffset(masm.currentOffset()), lhs));
  }
  void cmpl(Imm32 rhs, wasm::SymbolicAddress lhs) {
    JmpSrc src = masm.cmpl_im_disp32(rhs.value, (void*)-1);
    append(wasm::SymbolicAccess(CodeOffset(src.offset()), lhs));
  }

  void adcl(Imm32 imm, Register dest) {
    masm.adcl_ir(imm.value, dest.encoding());
  }
  void adcl(Register src, Register dest) {
    masm.adcl_rr(src.encoding(), dest.encoding());
  }
  void adcl(Operand src, Register dest) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.adcl_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.adcl_mr(src.disp(), src.base(), src.index(), src.scale(),
                     dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void sbbl(Imm32 imm, Register dest) {
    masm.sbbl_ir(imm.value, dest.encoding());
  }
  void sbbl(Register src, Register dest) {
    masm.sbbl_rr(src.encoding(), dest.encoding());
  }
  void sbbl(Operand src, Register dest) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.sbbl_mr(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.sbbl_mr(src.disp(), src.base(), src.index(), src.scale(),
                     dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void mull(Register multiplier) { masm.mull_r(multiplier.encoding()); }

  void shldl(const Imm32 imm, Register src, Register dest) {
    masm.shldl_irr(imm.value, src.encoding(), dest.encoding());
  }
  void shrdl(const Imm32 imm, Register src, Register dest) {
    masm.shrdl_irr(imm.value, src.encoding(), dest.encoding());
  }

  void vhaddpd(FloatRegister rhs, FloatRegister lhsDest) {
    MOZ_ASSERT(HasSSE3());
    MOZ_ASSERT(rhs.size() == 16);
    MOZ_ASSERT(lhsDest.size() == 16);
    masm.vhaddpd_rr(rhs.encoding(), lhsDest.encoding(), lhsDest.encoding());
  }

  void fild(const Operand& src) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.fild_m(src.disp(), src.base());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }

  void jmp(ImmPtr target, RelocationKind reloc = RelocationKind::HARDCODED) {
    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;
  }

  // Re-routes pending jumps to an external target, flushing the label in the
  // process.
  void retarget(Label* label, ImmPtr target, RelocationKind reloc) {
    if (label->used()) {
      bool more;
      X86Encoding::JmpSrc jmp(label->offset());
      do {
        X86Encoding::JmpSrc next;
        more = masm.nextJump(jmp, &next);
        addPendingJump(jmp, target, reloc);
        jmp = next;
      } while (more);
    }
    label->reset();
  }

  // Move a 32-bit immediate into a register where the immediate can be
  // patched.
  CodeOffset movlWithPatch(Imm32 imm, Register dest) {
    masm.movl_i32r(imm.value, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }

  // Load from *(base + disp32) where disp32 can be patched.
  CodeOffset movsblWithPatch(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.movsbl_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movsbl_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movzblWithPatch(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.movzbl_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movzbl_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movswlWithPatch(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.movswl_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movswl_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movzwlWithPatch(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.movzwl_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movzwl_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movlWithPatch(const Operand& src, Register dest) {
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.movl_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movl_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovssWithPatch(const Operand& src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovss_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovss_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  void vmovss(const Operand& src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovss_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovss_mr(src.address(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.vmovss_mr(src.disp(), src.base(), src.index(), src.scale(),
                       dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  CodeOffset vmovdWithPatch(const Operand& src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovd_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovd_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovqWithPatch(const Operand& src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovq_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovq_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovsdWithPatch(const Operand& src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovsd_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovsd_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  void vmovsd(const Operand& src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovsd_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovsd_mr(src.address(), dest.encoding());
        break;
      case Operand::MEM_SCALE:
        masm.vmovsd_mr(src.disp(), src.base(), src.index(), src.scale(),
                       dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  CodeOffset vmovupsWithPatch(const Operand& src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovups_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovups_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovdquWithPatch(const Operand& src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    switch (src.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovdqu_mr_disp32(src.disp(), src.base(), dest.encoding());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovdqu_mr(src.address(), dest.encoding());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }

  // Store to *(base + disp32) where disp32 can be patched.
  CodeOffset movbWithPatch(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.movb_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movb_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movwWithPatch(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.movw_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movw_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movlWithPatch(Register src, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.movl_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.movl_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movlWithPatchLow(Register regLow, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP: {
        return movlWithPatch(regLow, LowWord(dest));
      }
      case Operand::MEM_ADDRESS32: {
        Operand low(
            PatchedAbsoluteAddress(uint32_t(dest.address()) + INT64LOW_OFFSET));
        return movlWithPatch(regLow, low);
      }
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  CodeOffset movlWithPatchHigh(Register regHigh, const Operand& dest) {
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP: {
        return movlWithPatch(regHigh, HighWord(dest));
      }
      case Operand::MEM_ADDRESS32: {
        Operand high(PatchedAbsoluteAddress(uint32_t(dest.address()) +
                                            INT64HIGH_OFFSET));
        return movlWithPatch(regHigh, high);
      }
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  CodeOffset vmovdWithPatch(FloatRegister src, const Operand& dest) {
    MOZ_ASSERT(HasSSE2());
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovd_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovd_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovqWithPatch(FloatRegister src, const Operand& dest) {
    MOZ_ASSERT(HasSSE2());
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovq_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovq_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovssWithPatch(FloatRegister src, const Operand& dest) {
    MOZ_ASSERT(HasSSE2());
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovss_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovss_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  void vmovss(FloatRegister src, const Operand& dest) {
    MOZ_ASSERT(HasSSE2());
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovss_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovss_rm(src.encoding(), dest.address());
        break;
      case Operand::MEM_SCALE:
        masm.vmovss_rm(src.encoding(), dest.disp(), dest.base(), dest.index(),
                       dest.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  CodeOffset vmovsdWithPatch(FloatRegister src, const Operand& dest) {
    MOZ_ASSERT(HasSSE2());
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovsd_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovsd_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  void vmovsd(FloatRegister src, const Operand& dest) {
    MOZ_ASSERT(HasSSE2());
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovsd_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovsd_rm(src.encoding(), dest.address());
        break;
      case Operand::MEM_SCALE:
        masm.vmovsd_rm(src.encoding(), dest.disp(), dest.base(), dest.index(),
                       dest.scale());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
  }
  CodeOffset vmovupsWithPatch(FloatRegister src, const Operand& dest) {
    MOZ_ASSERT(HasSSE2());
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovups_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovups_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovdquWithPatch(FloatRegister src, const Operand& dest) {
    MOZ_ASSERT(HasSSE2());
    switch (dest.kind()) {
      case Operand::MEM_REG_DISP:
        masm.vmovdqu_rm_disp32(src.encoding(), dest.disp(), dest.base());
        break;
      case Operand::MEM_ADDRESS32:
        masm.vmovdqu_rm(src.encoding(), dest.address());
        break;
      default:
        MOZ_CRASH("unexpected operand kind");
    }
    return CodeOffset(masm.currentOffset());
  }

  // Load from *(addr + index*scale) where addr can be patched.
  CodeOffset movlWithPatch(PatchedAbsoluteAddress addr, Register index,
                           Scale scale, Register dest) {
    masm.movl_mr(addr.addr, index.encoding(), scale, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }

  // Load from *src where src can be patched.
  CodeOffset movsblWithPatch(PatchedAbsoluteAddress src, Register dest) {
    masm.movsbl_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movzblWithPatch(PatchedAbsoluteAddress src, Register dest) {
    masm.movzbl_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movswlWithPatch(PatchedAbsoluteAddress src, Register dest) {
    masm.movswl_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movzwlWithPatch(PatchedAbsoluteAddress src, Register dest) {
    masm.movzwl_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movlWithPatch(PatchedAbsoluteAddress src, Register dest) {
    masm.movl_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovssWithPatch(PatchedAbsoluteAddress src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovss_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovdWithPatch(PatchedAbsoluteAddress src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovd_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovqWithPatch(PatchedAbsoluteAddress src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovq_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovsdWithPatch(PatchedAbsoluteAddress src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovsd_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovdqaWithPatch(PatchedAbsoluteAddress src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovdqa_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovdquWithPatch(PatchedAbsoluteAddress src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovdqu_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovapsWithPatch(PatchedAbsoluteAddress src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovaps_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovupsWithPatch(PatchedAbsoluteAddress src, FloatRegister dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovups_mr(src.addr, dest.encoding());
    return CodeOffset(masm.currentOffset());
  }

  // Store to *dest where dest can be patched.
  CodeOffset movbWithPatch(Register src, PatchedAbsoluteAddress dest) {
    masm.movb_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movwWithPatch(Register src, PatchedAbsoluteAddress dest) {
    masm.movw_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset movlWithPatch(Register src, PatchedAbsoluteAddress dest) {
    masm.movl_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovssWithPatch(FloatRegister src, PatchedAbsoluteAddress dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovss_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovdWithPatch(FloatRegister src, PatchedAbsoluteAddress dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovd_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovqWithPatch(FloatRegister src, PatchedAbsoluteAddress dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovq_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovsdWithPatch(FloatRegister src, PatchedAbsoluteAddress dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovsd_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovdqaWithPatch(FloatRegister src, PatchedAbsoluteAddress dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovdqa_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovapsWithPatch(FloatRegister src, PatchedAbsoluteAddress dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovaps_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovdquWithPatch(FloatRegister src, PatchedAbsoluteAddress dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovdqu_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
  CodeOffset vmovupsWithPatch(FloatRegister src, PatchedAbsoluteAddress dest) {
    MOZ_ASSERT(HasSSE2());
    masm.vmovups_rm(src.encoding(), dest.addr);
    return CodeOffset(masm.currentOffset());
  }
};

// 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 (usedIntArgs >= NumCallTempNonArgRegs) {
    return false;
  }
  *out = CallTempNonArgRegs[usedIntArgs];
  return true;
}

}  // namespace jit
}  // namespace js

#endif /* jit_x86_Assembler_x86_h */