jit/x64/CodeGenerator-x64.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 * 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/. */

#include "jit/x64/CodeGenerator-x64.h"

#include "mozilla/MathAlgorithms.h"

#include "jit/MIR.h"

#include "jit/MacroAssembler-inl.h"
#include "jit/shared/CodeGenerator-shared-inl.h"
#include "vm/JSScript-inl.h"

using namespace js;
using namespace js::jit;

using mozilla::DebugOnly;

CodeGeneratorX64::CodeGeneratorX64(MIRGenerator* gen, LIRGraph* graph,
                                   MacroAssembler* masm)
    : CodeGeneratorX86Shared(gen, graph, masm) {}

ValueOperand CodeGeneratorX64::ToValue(LInstruction* ins, size_t pos) {
  return ValueOperand(ToRegister(ins->getOperand(pos)));
}

ValueOperand CodeGeneratorX64::ToTempValue(LInstruction* ins, size_t pos) {
  return ValueOperand(ToRegister(ins->getTemp(pos)));
}

Operand CodeGeneratorX64::ToOperand64(const LInt64Allocation& a64) {
  const LAllocation& a = a64.value();
  MOZ_ASSERT(!a.isFloatReg());
  if (a.isGeneralReg()) return Operand(a.toGeneralReg()->reg());
  return Operand(masm.getStackPointer(), ToStackOffset(a));
}

FrameSizeClass FrameSizeClass::FromDepth(uint32_t frameDepth) {
  return FrameSizeClass::None();
}

FrameSizeClass FrameSizeClass::ClassLimit() { return FrameSizeClass(0); }

uint32_t FrameSizeClass::frameSize() const {
  MOZ_CRASH("x64 does not use frame size classes");
}

void CodeGeneratorX64::visitValue(LValue* value) {
  ValueOperand result = ToOutValue(value);
  masm.moveValue(value->value(), result);
}

void CodeGeneratorX64::visitBox(LBox* box) {
  const LAllocation* in = box->getOperand(0);
  ValueOperand result = ToOutValue(box);

  masm.moveValue(TypedOrValueRegister(box->type(), ToAnyRegister(in)), result);
}

void CodeGeneratorX64::visitUnbox(LUnbox* unbox) {
  MUnbox* mir = unbox->mir();

  if (mir->fallible()) {
    const ValueOperand value = ToValue(unbox, LUnbox::Input);
    Assembler::Condition cond;
    switch (mir->type()) {
      case MIRType::Int32:
        cond = masm.testInt32(Assembler::NotEqual, value);
        break;
      case MIRType::Boolean:
        cond = masm.testBoolean(Assembler::NotEqual, value);
        break;
      case MIRType::Object:
        cond = masm.testObject(Assembler::NotEqual, value);
        break;
      case MIRType::String:
        cond = masm.testString(Assembler::NotEqual, value);
        break;
      case MIRType::Symbol:
        cond = masm.testSymbol(Assembler::NotEqual, value);
        break;
      default:
        MOZ_CRASH("Given MIRType cannot be unboxed.");
    }
    bailoutIf(cond, unbox->snapshot());
  } else {
#ifdef DEBUG
    Operand input = ToOperand(unbox->getOperand(LUnbox::Input));
    JSValueTag tag = MIRTypeToTag(mir->type());
    Label ok;
    masm.splitTag(input, ScratchReg);
    masm.branch32(Assembler::Equal, ScratchReg, Imm32(tag), &ok);
    masm.assumeUnreachable("Infallible unbox type mismatch");
    masm.bind(&ok);
#endif
  }

  Operand input = ToOperand(unbox->getOperand(LUnbox::Input));
  Register result = ToRegister(unbox->output());
  switch (mir->type()) {
    case MIRType::Int32:
      masm.unboxInt32(input, result);
      break;
    case MIRType::Boolean:
      masm.unboxBoolean(input, result);
      break;
    case MIRType::Object:
      masm.unboxObject(input, result);
      break;
    case MIRType::String:
      masm.unboxString(input, result);
      break;
    case MIRType::Symbol:
      masm.unboxSymbol(input, result);
      break;
    default:
      MOZ_CRASH("Given MIRType cannot be unboxed.");
  }
}

void CodeGeneratorX64::visitCompareB(LCompareB* lir) {
  MCompare* mir = lir->mir();

  const ValueOperand lhs = ToValue(lir, LCompareB::Lhs);
  const LAllocation* rhs = lir->rhs();
  const Register output = ToRegister(lir->output());

  MOZ_ASSERT(mir->jsop() == JSOP_STRICTEQ || mir->jsop() == JSOP_STRICTNE);

  // Load boxed boolean in ScratchReg.
  ScratchRegisterScope scratch(masm);
  if (rhs->isConstant())
    masm.moveValue(rhs->toConstant()->toJSValue(), ValueOperand(scratch));
  else
    masm.boxValue(JSVAL_TYPE_BOOLEAN, ToRegister(rhs), scratch);

  // Perform the comparison.
  masm.cmpPtr(lhs.valueReg(), scratch);
  masm.emitSet(JSOpToCondition(mir->compareType(), mir->jsop()), output);
}

void CodeGeneratorX64::visitCompareBAndBranch(LCompareBAndBranch* lir) {
  MCompare* mir = lir->cmpMir();

  const ValueOperand lhs = ToValue(lir, LCompareBAndBranch::Lhs);
  const LAllocation* rhs = lir->rhs();

  MOZ_ASSERT(mir->jsop() == JSOP_STRICTEQ || mir->jsop() == JSOP_STRICTNE);

  // Load boxed boolean in ScratchReg.
  ScratchRegisterScope scratch(masm);
  if (rhs->isConstant())
    masm.moveValue(rhs->toConstant()->toJSValue(), ValueOperand(scratch));
  else
    masm.boxValue(JSVAL_TYPE_BOOLEAN, ToRegister(rhs), scratch);

  // Perform the comparison.
  masm.cmpPtr(lhs.valueReg(), scratch);
  emitBranch(JSOpToCondition(mir->compareType(), mir->jsop()), lir->ifTrue(),
             lir->ifFalse());
}

void CodeGeneratorX64::visitCompareBitwise(LCompareBitwise* lir) {
  MCompare* mir = lir->mir();
  const ValueOperand lhs = ToValue(lir, LCompareBitwise::LhsInput);
  const ValueOperand rhs = ToValue(lir, LCompareBitwise::RhsInput);
  const Register output = ToRegister(lir->output());

  MOZ_ASSERT(IsEqualityOp(mir->jsop()));

  masm.cmpPtr(lhs.valueReg(), rhs.valueReg());
  masm.emitSet(JSOpToCondition(mir->compareType(), mir->jsop()), output);
}

void CodeGeneratorX64::visitCompareBitwiseAndBranch(
    LCompareBitwiseAndBranch* lir) {
  MCompare* mir = lir->cmpMir();

  const ValueOperand lhs = ToValue(lir, LCompareBitwiseAndBranch::LhsInput);
  const ValueOperand rhs = ToValue(lir, LCompareBitwiseAndBranch::RhsInput);

  MOZ_ASSERT(mir->jsop() == JSOP_EQ || mir->jsop() == JSOP_STRICTEQ ||
             mir->jsop() == JSOP_NE || mir->jsop() == JSOP_STRICTNE);

  masm.cmpPtr(lhs.valueReg(), rhs.valueReg());
  emitBranch(JSOpToCondition(mir->compareType(), mir->jsop()), lir->ifTrue(),
             lir->ifFalse());
}

void CodeGeneratorX64::visitCompareI64(LCompareI64* lir) {
  MCompare* mir = lir->mir();
  MOZ_ASSERT(mir->compareType() == MCompare::Compare_Int64 ||
             mir->compareType() == MCompare::Compare_UInt64);

  const LInt64Allocation lhs = lir->getInt64Operand(LCompareI64::Lhs);
  const LInt64Allocation rhs = lir->getInt64Operand(LCompareI64::Rhs);
  Register lhsReg = ToRegister64(lhs).reg;
  Register output = ToRegister(lir->output());

  if (IsConstant(rhs))
    masm.cmpPtr(lhsReg, ImmWord(ToInt64(rhs)));
  else
    masm.cmpPtr(lhsReg, ToOperand64(rhs));

  bool isSigned = mir->compareType() == MCompare::Compare_Int64;
  masm.emitSet(JSOpToCondition(lir->jsop(), isSigned), output);
}

void CodeGeneratorX64::visitCompareI64AndBranch(LCompareI64AndBranch* lir) {
  MCompare* mir = lir->cmpMir();
  MOZ_ASSERT(mir->compareType() == MCompare::Compare_Int64 ||
             mir->compareType() == MCompare::Compare_UInt64);

  LInt64Allocation lhs = lir->getInt64Operand(LCompareI64::Lhs);
  LInt64Allocation rhs = lir->getInt64Operand(LCompareI64::Rhs);
  Register lhsReg = ToRegister64(lhs).reg;

  if (IsConstant(rhs))
    masm.cmpPtr(lhsReg, ImmWord(ToInt64(rhs)));
  else
    masm.cmpPtr(lhsReg, ToOperand64(rhs));

  bool isSigned = mir->compareType() == MCompare::Compare_Int64;
  emitBranch(JSOpToCondition(lir->jsop(), isSigned), lir->ifTrue(),
             lir->ifFalse());
}

void CodeGeneratorX64::visitDivOrModI64(LDivOrModI64* lir) {
  Register lhs = ToRegister(lir->lhs());
  Register rhs = ToRegister(lir->rhs());
  Register output = ToRegister(lir->output());

  MOZ_ASSERT_IF(lhs != rhs, rhs != rax);
  MOZ_ASSERT(rhs != rdx);
  MOZ_ASSERT_IF(output == rax, ToRegister(lir->remainder()) == rdx);
  MOZ_ASSERT_IF(output == rdx, ToRegister(lir->remainder()) == rax);

  Label done;

  // Put the lhs in rax.
  if (lhs != rax) masm.mov(lhs, rax);

  // Handle divide by zero.
  if (lir->canBeDivideByZero()) {
    Label nonZero;
    masm.branchTestPtr(Assembler::NonZero, rhs, rhs, &nonZero);
    masm.wasmTrap(wasm::Trap::IntegerDivideByZero, lir->bytecodeOffset());
    masm.bind(&nonZero);
  }

  // Handle an integer overflow exception from INT64_MIN / -1.
  if (lir->canBeNegativeOverflow()) {
    Label notOverflow;
    masm.branchPtr(Assembler::NotEqual, lhs, ImmWord(INT64_MIN), &notOverflow);
    masm.branchPtr(Assembler::NotEqual, rhs, ImmWord(-1), &notOverflow);
    if (lir->mir()->isMod())
      masm.xorl(output, output);
    else
      masm.wasmTrap(wasm::Trap::IntegerOverflow, lir->bytecodeOffset());
    masm.jump(&done);
    masm.bind(&notOverflow);
  }

  // Sign extend the lhs into rdx to make rdx:rax.
  masm.cqo();
  masm.idivq(rhs);

  masm.bind(&done);
}

void CodeGeneratorX64::visitUDivOrModI64(LUDivOrModI64* lir) {
  Register lhs = ToRegister(lir->lhs());
  Register rhs = ToRegister(lir->rhs());

  DebugOnly<Register> output = ToRegister(lir->output());
  MOZ_ASSERT_IF(lhs != rhs, rhs != rax);
  MOZ_ASSERT(rhs != rdx);
  MOZ_ASSERT_IF(output.value == rax, ToRegister(lir->remainder()) == rdx);
  MOZ_ASSERT_IF(output.value == rdx, ToRegister(lir->remainder()) == rax);

  // Put the lhs in rax.
  if (lhs != rax) masm.mov(lhs, rax);

  Label done;

  // Prevent divide by zero.
  if (lir->canBeDivideByZero()) {
    Label nonZero;
    masm.branchTestPtr(Assembler::NonZero, rhs, rhs, &nonZero);
    masm.wasmTrap(wasm::Trap::IntegerDivideByZero, lir->bytecodeOffset());
    masm.bind(&nonZero);
  }

  // Zero extend the lhs into rdx to make (rdx:rax).
  masm.xorl(rdx, rdx);
  masm.udivq(rhs);

  masm.bind(&done);
}

void CodeGeneratorX64::visitWasmSelectI64(LWasmSelectI64* lir) {
  MOZ_ASSERT(lir->mir()->type() == MIRType::Int64);

  Register cond = ToRegister(lir->condExpr());

  Operand falseExpr = ToOperandOrRegister64(lir->falseExpr());

  Register64 out = ToOutRegister64(lir);
  MOZ_ASSERT(ToRegister64(lir->trueExpr()) == out,
             "true expr is reused for input");

  masm.test32(cond, cond);
  masm.cmovzq(falseExpr, out.reg);
}

void CodeGeneratorX64::visitWasmReinterpretFromI64(
    LWasmReinterpretFromI64* lir) {
  MOZ_ASSERT(lir->mir()->type() == MIRType::Double);
  MOZ_ASSERT(lir->mir()->input()->type() == MIRType::Int64);
  masm.vmovq(ToRegister(lir->input()), ToFloatRegister(lir->output()));
}

void CodeGeneratorX64::visitWasmReinterpretToI64(LWasmReinterpretToI64* lir) {
  MOZ_ASSERT(lir->mir()->type() == MIRType::Int64);
  MOZ_ASSERT(lir->mir()->input()->type() == MIRType::Double);
  masm.vmovq(ToFloatRegister(lir->input()), ToRegister(lir->output()));
}

void CodeGeneratorX64::visitWasmUint32ToDouble(LWasmUint32ToDouble* lir) {
  masm.convertUInt32ToDouble(ToRegister(lir->input()),
                             ToFloatRegister(lir->output()));
}

void CodeGeneratorX64::visitWasmUint32ToFloat32(LWasmUint32ToFloat32* lir) {
  masm.convertUInt32ToFloat32(ToRegister(lir->input()),
                              ToFloatRegister(lir->output()));
}

void CodeGeneratorX64::wasmStore(const wasm::MemoryAccessDesc& access,
                                 const LAllocation* value, Operand dstAddr) {
  if (value->isConstant()) {
    MOZ_ASSERT(!access.isSimd());

    masm.memoryBarrierBefore(access.sync());

    const MConstant* mir = value->toConstant();
    Imm32 cst =
        Imm32(mir->type() == MIRType::Int32 ? mir->toInt32() : mir->toInt64());

    size_t storeOffset = masm.size();
    switch (access.type()) {
      case Scalar::Int8:
      case Scalar::Uint8:
        masm.movb(cst, dstAddr);
        break;
      case Scalar::Int16:
      case Scalar::Uint16:
        masm.movw(cst, dstAddr);
        break;
      case Scalar::Int32:
      case Scalar::Uint32:
        masm.movl(cst, dstAddr);
        break;
      case Scalar::Int64:
      case Scalar::Float32:
      case Scalar::Float64:
      case Scalar::Float32x4:
      case Scalar::Int8x16:
      case Scalar::Int16x8:
      case Scalar::Int32x4:
      case Scalar::Uint8Clamped:
      case Scalar::MaxTypedArrayViewType:
        MOZ_CRASH("unexpected array type");
    }
    masm.append(access, storeOffset, masm.framePushed());

    masm.memoryBarrierAfter(access.sync());
  } else {
    masm.wasmStore(access, ToAnyRegister(value), dstAddr);
  }
}

template <typename T>
void CodeGeneratorX64::emitWasmLoad(T* ins) {
  const MWasmLoad* mir = ins->mir();

  uint32_t offset = mir->access().offset();
  MOZ_ASSERT(offset < wasm::OffsetGuardLimit);

  const LAllocation* ptr = ins->ptr();
  Operand srcAddr = ptr->isBogus()
                        ? Operand(HeapReg, offset)
                        : Operand(HeapReg, ToRegister(ptr), TimesOne, offset);

  if (mir->type() == MIRType::Int64)
    masm.wasmLoadI64(mir->access(), srcAddr, ToOutRegister64(ins));
  else
    masm.wasmLoad(mir->access(), srcAddr, ToAnyRegister(ins->output()));
}

void CodeGeneratorX64::visitWasmLoad(LWasmLoad* ins) { emitWasmLoad(ins); }

void CodeGeneratorX64::visitWasmLoadI64(LWasmLoadI64* ins) {
  emitWasmLoad(ins);
}

template <typename T>
void CodeGeneratorX64::emitWasmStore(T* ins) {
  const MWasmStore* mir = ins->mir();
  const wasm::MemoryAccessDesc& access = mir->access();

  uint32_t offset = access.offset();
  MOZ_ASSERT(offset < wasm::OffsetGuardLimit);

  const LAllocation* value = ins->getOperand(ins->ValueIndex);
  const LAllocation* ptr = ins->ptr();
  Operand dstAddr = ptr->isBogus()
                        ? Operand(HeapReg, offset)
                        : Operand(HeapReg, ToRegister(ptr), TimesOne, offset);

  wasmStore(access, value, dstAddr);
}

void CodeGeneratorX64::visitWasmStore(LWasmStore* ins) { emitWasmStore(ins); }

void CodeGeneratorX64::visitWasmStoreI64(LWasmStoreI64* ins) {
  emitWasmStore(ins);
}

void CodeGeneratorX64::visitAsmJSLoadHeap(LAsmJSLoadHeap* ins) {
  const MAsmJSLoadHeap* mir = ins->mir();
  MOZ_ASSERT(mir->offset() < wasm::OffsetGuardLimit);

  const LAllocation* ptr = ins->ptr();
  const LDefinition* out = ins->output();

  Scalar::Type accessType = mir->access().type();
  MOZ_ASSERT(!Scalar::isSimdType(accessType));

  Operand srcAddr = ptr->isBogus() ? Operand(HeapReg, mir->offset())
                                   : Operand(HeapReg, ToRegister(ptr), TimesOne,
                                             mir->offset());

  uint32_t before = masm.size();
  masm.wasmLoad(mir->access(), srcAddr, ToAnyRegister(out));
  uint32_t after = masm.size();
  verifyLoadDisassembly(before, after, accessType, srcAddr, *out->output());
}

void CodeGeneratorX64::visitAsmJSStoreHeap(LAsmJSStoreHeap* ins) {
  const MAsmJSStoreHeap* mir = ins->mir();
  MOZ_ASSERT(mir->offset() < wasm::OffsetGuardLimit);

  const LAllocation* ptr = ins->ptr();
  const LAllocation* value = ins->value();

  Scalar::Type accessType = mir->access().type();
  MOZ_ASSERT(!Scalar::isSimdType(accessType));

  canonicalizeIfDeterministic(accessType, value);

  Operand dstAddr = ptr->isBogus() ? Operand(HeapReg, mir->offset())
                                   : Operand(HeapReg, ToRegister(ptr), TimesOne,
                                             mir->offset());

  uint32_t before = masm.size();
  wasmStore(mir->access(), value, dstAddr);
  uint32_t after = masm.size();
  verifyStoreDisassembly(before, after, accessType, dstAddr, *value);
}

void CodeGeneratorX64::visitWasmCompareExchangeHeap(
    LWasmCompareExchangeHeap* ins) {
  MWasmCompareExchangeHeap* mir = ins->mir();

  Register ptr = ToRegister(ins->ptr());
  Register oldval = ToRegister(ins->oldValue());
  Register newval = ToRegister(ins->newValue());
  MOZ_ASSERT(ins->addrTemp()->isBogusTemp());

  Scalar::Type accessType = mir->access().type();
  BaseIndex srcAddr(HeapReg, ptr, TimesOne, mir->access().offset());

  if (accessType == Scalar::Int64) {
    MOZ_ASSERT(!mir->access().isPlainAsmJS());
    masm.compareExchange64(Synchronization::Full(), srcAddr, Register64(oldval),
                           Register64(newval), ToOutRegister64(ins));
  } else {
    masm.compareExchange(accessType, Synchronization::Full(), srcAddr, oldval,
                         newval, ToRegister(ins->output()));
  }
}

void CodeGeneratorX64::visitWasmAtomicExchangeHeap(
    LWasmAtomicExchangeHeap* ins) {
  MWasmAtomicExchangeHeap* mir = ins->mir();

  Register ptr = ToRegister(ins->ptr());
  Register value = ToRegister(ins->value());
  MOZ_ASSERT(ins->addrTemp()->isBogusTemp());

  Scalar::Type accessType = mir->access().type();

  BaseIndex srcAddr(HeapReg, ptr, TimesOne, mir->access().offset());

  if (accessType == Scalar::Int64) {
    MOZ_ASSERT(!mir->access().isPlainAsmJS());
    masm.atomicExchange64(Synchronization::Full(), srcAddr, Register64(value),
                          ToOutRegister64(ins));
  } else {
    masm.atomicExchange(accessType, Synchronization::Full(), srcAddr, value,
                        ToRegister(ins->output()));
  }
}

void CodeGeneratorX64::visitWasmAtomicBinopHeap(LWasmAtomicBinopHeap* ins) {
  MWasmAtomicBinopHeap* mir = ins->mir();
  MOZ_ASSERT(mir->hasUses());

  Register ptr = ToRegister(ins->ptr());
  const LAllocation* value = ins->value();
  Register temp =
      ins->temp()->isBogusTemp() ? InvalidReg : ToRegister(ins->temp());
  Register output = ToRegister(ins->output());
  MOZ_ASSERT(ins->addrTemp()->isBogusTemp());

  Scalar::Type accessType = mir->access().type();
  if (accessType == Scalar::Uint32) accessType = Scalar::Int32;

  AtomicOp op = mir->operation();
  BaseIndex srcAddr(HeapReg, ptr, TimesOne, mir->access().offset());

  if (accessType == Scalar::Int64) {
    Register64 val = Register64(ToRegister(value));
    Register64 out = Register64(output);
    Register64 tmp = Register64(temp);
    masm.atomicFetchOp64(Synchronization::Full(), op, val, srcAddr, tmp, out);
  } else if (value->isConstant()) {
    masm.atomicFetchOp(accessType, Synchronization::Full(), op,
                       Imm32(ToInt32(value)), srcAddr, temp, output);
  } else {
    masm.atomicFetchOp(accessType, Synchronization::Full(), op,
                       ToRegister(value), srcAddr, temp, output);
  }
}

void CodeGeneratorX64::visitWasmAtomicBinopHeapForEffect(
    LWasmAtomicBinopHeapForEffect* ins) {
  MWasmAtomicBinopHeap* mir = ins->mir();
  MOZ_ASSERT(!mir->hasUses());

  Register ptr = ToRegister(ins->ptr());
  const LAllocation* value = ins->value();
  MOZ_ASSERT(ins->addrTemp()->isBogusTemp());

  Scalar::Type accessType = mir->access().type();
  AtomicOp op = mir->operation();

  BaseIndex srcAddr(HeapReg, ptr, TimesOne, mir->access().offset());

  if (accessType == Scalar::Int64) {
    Register64 val = Register64(ToRegister(value));
    masm.atomicEffectOp64(Synchronization::Full(), op, val, srcAddr);
  } else if (value->isConstant()) {
    Imm32 c(0);
    if (value->toConstant()->type() == MIRType::Int64)
      c = Imm32(ToInt64(value));
    else
      c = Imm32(ToInt32(value));
    masm.atomicEffectOp(accessType, Synchronization::Full(), op, c, srcAddr,
                        InvalidReg);
  } else {
    masm.atomicEffectOp(accessType, Synchronization::Full(), op,
                        ToRegister(value), srcAddr, InvalidReg);
  }
}

void CodeGeneratorX64::visitTruncateDToInt32(LTruncateDToInt32* ins) {
  FloatRegister input = ToFloatRegister(ins->input());
  Register output = ToRegister(ins->output());

  // On x64, branchTruncateDouble uses vcvttsd2sq. Unlike the x86
  // implementation, this should handle most doubles and we can just
  // call a stub if it fails.
  emitTruncateDouble(input, output, ins->mir());
}

void CodeGeneratorX64::visitTruncateFToInt32(LTruncateFToInt32* ins) {
  FloatRegister input = ToFloatRegister(ins->input());
  Register output = ToRegister(ins->output());

  // On x64, branchTruncateFloat32 uses vcvttss2sq. Unlike the x86
  // implementation, this should handle most floats and we can just
  // call a stub if it fails.
  emitTruncateFloat32(input, output, ins->mir());
}

void CodeGeneratorX64::visitWrapInt64ToInt32(LWrapInt64ToInt32* lir) {
  const LAllocation* input = lir->getOperand(0);
  Register output = ToRegister(lir->output());

  if (lir->mir()->bottomHalf())
    masm.movl(ToOperand(input), output);
  else
    MOZ_CRASH("Not implemented.");
}

void CodeGeneratorX64::visitExtendInt32ToInt64(LExtendInt32ToInt64* lir) {
  const LAllocation* input = lir->getOperand(0);
  Register output = ToRegister(lir->output());

  if (lir->mir()->isUnsigned())
    masm.movl(ToOperand(input), output);
  else
    masm.movslq(ToOperand(input), output);
}

void CodeGeneratorX64::visitSignExtendInt64(LSignExtendInt64* ins) {
  Register64 input = ToRegister64(ins->getInt64Operand(0));
  Register64 output = ToOutRegister64(ins);
  switch (ins->mode()) {
    case MSignExtendInt64::Byte:
      masm.movsbq(Operand(input.reg), output.reg);
      break;
    case MSignExtendInt64::Half:
      masm.movswq(Operand(input.reg), output.reg);
      break;
    case MSignExtendInt64::Word:
      masm.movslq(Operand(input.reg), output.reg);
      break;
  }
}

void CodeGeneratorX64::visitWasmTruncateToInt64(LWasmTruncateToInt64* lir) {
  FloatRegister input = ToFloatRegister(lir->input());
  Register64 output = ToOutRegister64(lir);

  MWasmTruncateToInt64* mir = lir->mir();
  MIRType inputType = mir->input()->type();

  MOZ_ASSERT(inputType == MIRType::Double || inputType == MIRType::Float32);

  auto* ool = new (alloc()) OutOfLineWasmTruncateCheck(mir, input, output);
  addOutOfLineCode(ool, mir);

  FloatRegister temp =
      mir->isUnsigned() ? ToFloatRegister(lir->temp()) : InvalidFloatReg;

  Label* oolEntry = ool->entry();
  Label* oolRejoin = ool->rejoin();
  bool isSaturating = mir->isSaturating();
  if (inputType == MIRType::Double) {
    if (mir->isUnsigned())
      masm.wasmTruncateDoubleToUInt64(input, output, isSaturating, oolEntry,
                                      oolRejoin, temp);
    else
      masm.wasmTruncateDoubleToInt64(input, output, isSaturating, oolEntry,
                                     oolRejoin, temp);
  } else {
    if (mir->isUnsigned())
      masm.wasmTruncateFloat32ToUInt64(input, output, isSaturating, oolEntry,
                                       oolRejoin, temp);
    else
      masm.wasmTruncateFloat32ToInt64(input, output, isSaturating, oolEntry,
                                      oolRejoin, temp);
  }
}

void CodeGeneratorX64::visitInt64ToFloatingPoint(LInt64ToFloatingPoint* lir) {
  Register64 input = ToRegister64(lir->getInt64Operand(0));
  FloatRegister output = ToFloatRegister(lir->output());

  MInt64ToFloatingPoint* mir = lir->mir();
  bool isUnsigned = mir->isUnsigned();

  MIRType outputType = mir->type();
  MOZ_ASSERT(outputType == MIRType::Double || outputType == MIRType::Float32);
  MOZ_ASSERT(isUnsigned == !lir->getTemp(0)->isBogusTemp());

  if (outputType == MIRType::Double) {
    if (isUnsigned)
      masm.convertUInt64ToDouble(input, output, ToRegister(lir->getTemp(0)));
    else
      masm.convertInt64ToDouble(input, output);
  } else {
    if (isUnsigned)
      masm.convertUInt64ToFloat32(input, output, ToRegister(lir->getTemp(0)));
    else
      masm.convertInt64ToFloat32(input, output);
  }
}

void CodeGeneratorX64::visitNotI64(LNotI64* lir) {
  masm.cmpq(Imm32(0), ToRegister(lir->input()));
  masm.emitSet(Assembler::Equal, ToRegister(lir->output()));
}

void CodeGeneratorX64::visitClzI64(LClzI64* lir) {
  Register64 input = ToRegister64(lir->getInt64Operand(0));
  Register64 output = ToOutRegister64(lir);
  masm.clz64(input, output.reg);
}

void CodeGeneratorX64::visitCtzI64(LCtzI64* lir) {
  Register64 input = ToRegister64(lir->getInt64Operand(0));
  Register64 output = ToOutRegister64(lir);
  masm.ctz64(input, output.reg);
}

void CodeGeneratorX64::visitTestI64AndBranch(LTestI64AndBranch* lir) {
  Register input = ToRegister(lir->input());
  masm.testq(input, input);
  emitBranch(Assembler::NonZero, lir->ifTrue(), lir->ifFalse());
}