Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1438 insertions, 0 deletions

diff --git a/js/src/jit/arm64/Lowering-arm64.cpp b/js/src/jit/arm64/Lowering-arm64.cpp
new file mode 100644
index 0000000000..d71f22089d
--- /dev/null
+++ b/js/src/jit/arm64/Lowering-arm64.cpp
@@ -0,0 +1,1438 @@
+/* -*- 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/. */
+
+#include "jit/arm64/Lowering-arm64.h"
+
+#include "mozilla/MathAlgorithms.h"
+
+#include "jit/arm64/Assembler-arm64.h"
+#include "jit/Lowering.h"
+#include "jit/MIR.h"
+#include "jit/shared/Lowering-shared-inl.h"
+
+using namespace js;
+using namespace js::jit;
+
+using mozilla::FloorLog2;
+
+LBoxAllocation LIRGeneratorARM64::useBoxFixed(MDefinition* mir, Register reg1,
+                                              Register, bool useAtStart) {
+  MOZ_ASSERT(mir->type() == MIRType::Value);
+
+  ensureDefined(mir);
+  return LBoxAllocation(LUse(reg1, mir->virtualRegister(), useAtStart));
+}
+
+LAllocation LIRGeneratorARM64::useByteOpRegister(MDefinition* mir) {
+  return useRegister(mir);
+}
+
+LAllocation LIRGeneratorARM64::useByteOpRegisterAtStart(MDefinition* mir) {
+  return useRegisterAtStart(mir);
+}
+
+LAllocation LIRGeneratorARM64::useByteOpRegisterOrNonDoubleConstant(
+    MDefinition* mir) {
+  return useRegisterOrNonDoubleConstant(mir);
+}
+
+LDefinition LIRGeneratorARM64::tempByteOpRegister() { return temp(); }
+
+LDefinition LIRGeneratorARM64::tempToUnbox() { return temp(); }
+
+void LIRGenerator::visitBox(MBox* box) {
+  MDefinition* opd = box->getOperand(0);
+
+  // If the operand is a constant, emit near its uses.
+  if (opd->isConstant() && box->canEmitAtUses()) {
+    emitAtUses(box);
+    return;
+  }
+
+  if (opd->isConstant()) {
+    define(new (alloc()) LValue(opd->toConstant()->toJSValue()), box,
+           LDefinition(LDefinition::BOX));
+  } else {
+    LBox* ins = new (alloc()) LBox(useRegister(opd), opd->type());
+    define(ins, box, LDefinition(LDefinition::BOX));
+  }
+}
+
+void LIRGenerator::visitUnbox(MUnbox* unbox) {
+  MDefinition* box = unbox->getOperand(0);
+  MOZ_ASSERT(box->type() == MIRType::Value);
+
+  LUnboxBase* lir;
+  if (IsFloatingPointType(unbox->type())) {
+    lir = new (alloc())
+        LUnboxFloatingPoint(useRegisterAtStart(box), unbox->type());
+  } else if (unbox->fallible()) {
+    // If the unbox is fallible, load the Value in a register first to
+    // avoid multiple loads.
+    lir = new (alloc()) LUnbox(useRegisterAtStart(box));
+  } else {
+    // FIXME: It should be possible to useAtStart() here, but the DEBUG
+    // code in CodeGenerator::visitUnbox() needs to handle non-Register
+    // cases. ARM64 doesn't have an Operand type.
+    lir = new (alloc()) LUnbox(useRegisterAtStart(box));
+  }
+
+  if (unbox->fallible()) {
+    assignSnapshot(lir, unbox->bailoutKind());
+  }
+
+  define(lir, unbox);
+}
+
+void LIRGenerator::visitReturnImpl(MDefinition* opd, bool isGenerator) {
+  MOZ_ASSERT(opd->type() == MIRType::Value);
+
+  LReturn* ins = new (alloc()) LReturn(isGenerator);
+  ins->setOperand(0, useFixed(opd, JSReturnReg));
+  add(ins);
+}
+
+// x = !y
+void LIRGeneratorARM64::lowerForALU(LInstructionHelper<1, 1, 0>* ins,
+                                    MDefinition* mir, MDefinition* input) {
+  ins->setOperand(
+      0, ins->snapshot() ? useRegister(input) : useRegisterAtStart(input));
+  define(
+      ins, mir,
+      LDefinition(LDefinition::TypeFrom(mir->type()), LDefinition::REGISTER));
+}
+
+// z = x+y
+void LIRGeneratorARM64::lowerForALU(LInstructionHelper<1, 2, 0>* ins,
+                                    MDefinition* mir, MDefinition* lhs,
+                                    MDefinition* rhs) {
+  ins->setOperand(0,
+                  ins->snapshot() ? useRegister(lhs) : useRegisterAtStart(lhs));
+  ins->setOperand(1, ins->snapshot() ? useRegisterOrConstant(rhs)
+                                     : useRegisterOrConstantAtStart(rhs));
+  define(
+      ins, mir,
+      LDefinition(LDefinition::TypeFrom(mir->type()), LDefinition::REGISTER));
+}
+
+void LIRGeneratorARM64::lowerForFPU(LInstructionHelper<1, 1, 0>* ins,
+                                    MDefinition* mir, MDefinition* input) {
+  ins->setOperand(0, useRegisterAtStart(input));
+  define(
+      ins, mir,
+      LDefinition(LDefinition::TypeFrom(mir->type()), LDefinition::REGISTER));
+}
+
+template <size_t Temps>
+void LIRGeneratorARM64::lowerForFPU(LInstructionHelper<1, 2, Temps>* ins,
+                                    MDefinition* mir, MDefinition* lhs,
+                                    MDefinition* rhs) {
+  ins->setOperand(0, useRegisterAtStart(lhs));
+  ins->setOperand(1, useRegisterAtStart(rhs));
+  define(
+      ins, mir,
+      LDefinition(LDefinition::TypeFrom(mir->type()), LDefinition::REGISTER));
+}
+
+template void LIRGeneratorARM64::lowerForFPU(LInstructionHelper<1, 2, 0>* ins,
+                                             MDefinition* mir, MDefinition* lhs,
+                                             MDefinition* rhs);
+template void LIRGeneratorARM64::lowerForFPU(LInstructionHelper<1, 2, 1>* ins,
+                                             MDefinition* mir, MDefinition* lhs,
+                                             MDefinition* rhs);
+
+void LIRGeneratorARM64::lowerForALUInt64(
+    LInstructionHelper<INT64_PIECES, INT64_PIECES, 0>* ins, MDefinition* mir,
+    MDefinition* input) {
+  ins->setInt64Operand(0, useInt64RegisterAtStart(input));
+  defineInt64(ins, mir);
+}
+
+// These all currently have codegen that depends on reuse but only because the
+// masm API depends on that.  We need new three-address masm APIs, for both
+// constant and variable rhs.
+//
+// MAdd => LAddI64
+// MSub => LSubI64
+// MBitAnd, MBitOr, MBitXor => LBitOpI64
+void LIRGeneratorARM64::lowerForALUInt64(
+    LInstructionHelper<INT64_PIECES, 2 * INT64_PIECES, 0>* ins,
+    MDefinition* mir, MDefinition* lhs, MDefinition* rhs) {
+  ins->setInt64Operand(0, useInt64RegisterAtStart(lhs));
+  ins->setInt64Operand(INT64_PIECES, useInt64RegisterOrConstantAtStart(rhs));
+  defineInt64(ins, mir);
+}
+
+void LIRGeneratorARM64::lowerForMulInt64(LMulI64* ins, MMul* mir,
+                                         MDefinition* lhs, MDefinition* rhs) {
+  ins->setInt64Operand(LMulI64::Lhs, useInt64RegisterAtStart(lhs));
+  ins->setInt64Operand(LMulI64::Rhs, useInt64RegisterOrConstantAtStart(rhs));
+  defineInt64(ins, mir);
+}
+
+template <size_t Temps>
+void LIRGeneratorARM64::lowerForShiftInt64(
+    LInstructionHelper<INT64_PIECES, INT64_PIECES + 1, Temps>* ins,
+    MDefinition* mir, MDefinition* lhs, MDefinition* rhs) {
+  ins->setInt64Operand(0, useInt64RegisterAtStart(lhs));
+
+  static_assert(LShiftI64::Rhs == INT64_PIECES,
+                "Assume Rhs is located at INT64_PIECES.");
+  static_assert(LRotateI64::Count == INT64_PIECES,
+                "Assume Count is located at INT64_PIECES.");
+
+  ins->setOperand(INT64_PIECES, useRegisterOrConstantAtStart(rhs));
+  defineInt64(ins, mir);
+}
+
+template void LIRGeneratorARM64::lowerForShiftInt64(
+    LInstructionHelper<INT64_PIECES, INT64_PIECES + 1, 0>* ins,
+    MDefinition* mir, MDefinition* lhs, MDefinition* rhs);
+template void LIRGeneratorARM64::lowerForShiftInt64(
+    LInstructionHelper<INT64_PIECES, INT64_PIECES + 1, 1>* ins,
+    MDefinition* mir, MDefinition* lhs, MDefinition* rhs);
+
+void LIRGeneratorARM64::lowerForCompareI64AndBranch(MTest* mir, MCompare* comp,
+                                                    JSOp op, MDefinition* left,
+                                                    MDefinition* right,
+                                                    MBasicBlock* ifTrue,
+                                                    MBasicBlock* ifFalse) {
+  auto* lir = new (alloc())
+      LCompareI64AndBranch(comp, op, useInt64Register(left),
+                           useInt64RegisterOrConstant(right), ifTrue, ifFalse);
+  add(lir, mir);
+}
+
+void LIRGeneratorARM64::lowerForBitAndAndBranch(LBitAndAndBranch* baab,
+                                                MInstruction* mir,
+                                                MDefinition* lhs,
+                                                MDefinition* rhs) {
+  baab->setOperand(0, useRegisterAtStart(lhs));
+  baab->setOperand(1, useRegisterOrConstantAtStart(rhs));
+  add(baab, mir);
+}
+
+void LIRGeneratorARM64::lowerWasmBuiltinTruncateToInt32(
+    MWasmBuiltinTruncateToInt32* ins) {
+  MDefinition* opd = ins->input();
+  MOZ_ASSERT(opd->type() == MIRType::Double || opd->type() == MIRType::Float32);
+
+  if (opd->type() == MIRType::Double) {
+    define(new (alloc()) LWasmBuiltinTruncateDToInt32(
+               useRegister(opd), useFixed(ins->instance(), InstanceReg),
+               LDefinition::BogusTemp()),
+           ins);
+    return;
+  }
+
+  define(new (alloc()) LWasmBuiltinTruncateFToInt32(
+             useRegister(opd), useFixed(ins->instance(), InstanceReg),
+             LDefinition::BogusTemp()),
+         ins);
+}
+
+void LIRGeneratorARM64::lowerUntypedPhiInput(MPhi* phi, uint32_t inputPosition,
+                                             LBlock* block, size_t lirIndex) {
+  lowerTypedPhiInput(phi, inputPosition, block, lirIndex);
+}
+
+void LIRGeneratorARM64::lowerForShift(LInstructionHelper<1, 2, 0>* ins,
+                                      MDefinition* mir, MDefinition* lhs,
+                                      MDefinition* rhs) {
+  ins->setOperand(0, useRegister(lhs));
+  ins->setOperand(1, useRegisterOrConstant(rhs));
+  define(ins, mir);
+}
+
+void LIRGeneratorARM64::lowerDivI(MDiv* div) {
+  if (div->isUnsigned()) {
+    lowerUDiv(div);
+    return;
+  }
+
+  if (div->rhs()->isConstant()) {
+    LAllocation lhs = useRegister(div->lhs());
+    int32_t rhs = div->rhs()->toConstant()->toInt32();
+    int32_t shift = mozilla::FloorLog2(mozilla::Abs(rhs));
+
+    if (rhs != 0 && uint32_t(1) << shift == mozilla::Abs(rhs)) {
+      LDivPowTwoI* lir = new (alloc()) LDivPowTwoI(lhs, shift, rhs < 0);
+      if (div->fallible()) {
+        assignSnapshot(lir, div->bailoutKind());
+      }
+      define(lir, div);
+      return;
+    }
+    if (rhs != 0) {
+      LDivConstantI* lir = new (alloc()) LDivConstantI(lhs, rhs, temp());
+      if (div->fallible()) {
+        assignSnapshot(lir, div->bailoutKind());
+      }
+      define(lir, div);
+      return;
+    }
+  }
+
+  LDivI* lir = new (alloc())
+      LDivI(useRegister(div->lhs()), useRegister(div->rhs()), temp());
+  if (div->fallible()) {
+    assignSnapshot(lir, div->bailoutKind());
+  }
+  define(lir, div);
+}
+
+void LIRGeneratorARM64::lowerNegI(MInstruction* ins, MDefinition* input) {
+  define(new (alloc()) LNegI(useRegisterAtStart(input)), ins);
+}
+
+void LIRGeneratorARM64::lowerNegI64(MInstruction* ins, MDefinition* input) {
+  defineInt64(new (alloc()) LNegI64(useInt64RegisterAtStart(input)), ins);
+}
+
+void LIRGeneratorARM64::lowerMulI(MMul* mul, MDefinition* lhs,
+                                  MDefinition* rhs) {
+  LMulI* lir = new (alloc()) LMulI;
+  if (mul->fallible()) {
+    assignSnapshot(lir, mul->bailoutKind());
+  }
+  lowerForALU(lir, mul, lhs, rhs);
+}
+
+void LIRGeneratorARM64::lowerModI(MMod* mod) {
+  if (mod->isUnsigned()) {
+    lowerUMod(mod);
+    return;
+  }
+
+  if (mod->rhs()->isConstant()) {
+    int32_t rhs = mod->rhs()->toConstant()->toInt32();
+    int32_t shift = FloorLog2(rhs);
+    if (rhs > 0 && 1 << shift == rhs) {
+      LModPowTwoI* lir =
+          new (alloc()) LModPowTwoI(useRegister(mod->lhs()), shift);
+      if (mod->fallible()) {
+        assignSnapshot(lir, mod->bailoutKind());
+      }
+      define(lir, mod);
+      return;
+    } else if (shift < 31 && (1 << (shift + 1)) - 1 == rhs) {
+      LModMaskI* lir = new (alloc())
+          LModMaskI(useRegister(mod->lhs()), temp(), temp(), shift + 1);
+      if (mod->fallible()) {
+        assignSnapshot(lir, mod->bailoutKind());
+      }
+      define(lir, mod);
+    }
+  }
+
+  LModI* lir =
+      new (alloc()) LModI(useRegister(mod->lhs()), useRegister(mod->rhs()));
+  if (mod->fallible()) {
+    assignSnapshot(lir, mod->bailoutKind());
+  }
+  define(lir, mod);
+}
+
+void LIRGeneratorARM64::lowerDivI64(MDiv* div) {
+  if (div->isUnsigned()) {
+    lowerUDivI64(div);
+    return;
+  }
+
+  LDivOrModI64* lir = new (alloc())
+      LDivOrModI64(useRegister(div->lhs()), useRegister(div->rhs()));
+  defineInt64(lir, div);
+}
+
+void LIRGeneratorARM64::lowerUDivI64(MDiv* div) {
+  LUDivOrModI64* lir = new (alloc())
+      LUDivOrModI64(useRegister(div->lhs()), useRegister(div->rhs()));
+  defineInt64(lir, div);
+}
+
+void LIRGeneratorARM64::lowerUModI64(MMod* mod) {
+  LUDivOrModI64* lir = new (alloc())
+      LUDivOrModI64(useRegister(mod->lhs()), useRegister(mod->rhs()));
+  defineInt64(lir, mod);
+}
+
+void LIRGeneratorARM64::lowerWasmBuiltinDivI64(MWasmBuiltinDivI64* div) {
+  MOZ_CRASH("We don't use runtime div for this architecture");
+}
+
+void LIRGeneratorARM64::lowerModI64(MMod* mod) {
+  if (mod->isUnsigned()) {
+    lowerUModI64(mod);
+    return;
+  }
+
+  LDivOrModI64* lir = new (alloc())
+      LDivOrModI64(useRegister(mod->lhs()), useRegister(mod->rhs()));
+  defineInt64(lir, mod);
+}
+
+void LIRGeneratorARM64::lowerWasmBuiltinModI64(MWasmBuiltinModI64* mod) {
+  MOZ_CRASH("We don't use runtime mod for this architecture");
+}
+
+void LIRGenerator::visitPowHalf(MPowHalf* ins) {
+  MDefinition* input = ins->input();
+  MOZ_ASSERT(input->type() == MIRType::Double);
+  LPowHalfD* lir = new (alloc()) LPowHalfD(useRegister(input));
+  define(lir, ins);
+}
+
+void LIRGeneratorARM64::lowerWasmSelectI(MWasmSelect* select) {
+  if (select->type() == MIRType::Simd128) {
+    LAllocation t = useRegisterAtStart(select->trueExpr());
+    LAllocation f = useRegister(select->falseExpr());
+    LAllocation c = useRegister(select->condExpr());
+    auto* lir = new (alloc()) LWasmSelect(t, f, c);
+    defineReuseInput(lir, select, LWasmSelect::TrueExprIndex);
+  } else {
+    LAllocation t = useRegisterAtStart(select->trueExpr());
+    LAllocation f = useRegisterAtStart(select->falseExpr());
+    LAllocation c = useRegisterAtStart(select->condExpr());
+    define(new (alloc()) LWasmSelect(t, f, c), select);
+  }
+}
+
+void LIRGeneratorARM64::lowerWasmSelectI64(MWasmSelect* select) {
+  LInt64Allocation t = useInt64RegisterAtStart(select->trueExpr());
+  LInt64Allocation f = useInt64RegisterAtStart(select->falseExpr());
+  LAllocation c = useRegisterAtStart(select->condExpr());
+  defineInt64(new (alloc()) LWasmSelectI64(t, f, c), select);
+}
+
+// On arm64 we specialize the cases: compare is {{U,}Int32, {U,}Int64},
+// Float32, Double}, and select is {{U,}Int32, {U,}Int64}, Float32, Double},
+// independently.
+bool LIRGeneratorARM64::canSpecializeWasmCompareAndSelect(
+    MCompare::CompareType compTy, MIRType insTy) {
+  return (insTy == MIRType::Int32 || insTy == MIRType::Int64 ||
+          insTy == MIRType::Float32 || insTy == MIRType::Double) &&
+         (compTy == MCompare::Compare_Int32 ||
+          compTy == MCompare::Compare_UInt32 ||
+          compTy == MCompare::Compare_Int64 ||
+          compTy == MCompare::Compare_UInt64 ||
+          compTy == MCompare::Compare_Float32 ||
+          compTy == MCompare::Compare_Double);
+}
+
+void LIRGeneratorARM64::lowerWasmCompareAndSelect(MWasmSelect* ins,
+                                                  MDefinition* lhs,
+                                                  MDefinition* rhs,
+                                                  MCompare::CompareType compTy,
+                                                  JSOp jsop) {
+  MOZ_ASSERT(canSpecializeWasmCompareAndSelect(compTy, ins->type()));
+  LAllocation rhsAlloc;
+  if (compTy == MCompare::Compare_Float32 ||
+      compTy == MCompare::Compare_Double) {
+    rhsAlloc = useRegisterAtStart(rhs);
+  } else if (compTy == MCompare::Compare_Int32 ||
+             compTy == MCompare::Compare_UInt32 ||
+             compTy == MCompare::Compare_Int64 ||
+             compTy == MCompare::Compare_UInt64) {
+    rhsAlloc = useRegisterOrConstantAtStart(rhs);
+  } else {
+    MOZ_CRASH("Unexpected type");
+  }
+  auto* lir = new (alloc())
+      LWasmCompareAndSelect(useRegisterAtStart(lhs), rhsAlloc, compTy, jsop,
+                            useRegisterAtStart(ins->trueExpr()),
+                            useRegisterAtStart(ins->falseExpr()));
+  define(lir, ins);
+}
+
+void LIRGenerator::visitAbs(MAbs* ins) {
+  define(allocateAbs(ins, useRegisterAtStart(ins->input())), ins);
+}
+
+LTableSwitch* LIRGeneratorARM64::newLTableSwitch(const LAllocation& in,
+                                                 const LDefinition& inputCopy,
+                                                 MTableSwitch* tableswitch) {
+  return new (alloc()) LTableSwitch(in, inputCopy, temp(), tableswitch);
+}
+
+LTableSwitchV* LIRGeneratorARM64::newLTableSwitchV(MTableSwitch* tableswitch) {
+  return new (alloc()) LTableSwitchV(useBox(tableswitch->getOperand(0)), temp(),
+                                     tempDouble(), temp(), tableswitch);
+}
+
+void LIRGeneratorARM64::lowerUrshD(MUrsh* mir) {
+  MDefinition* lhs = mir->lhs();
+  MDefinition* rhs = mir->rhs();
+
+  MOZ_ASSERT(lhs->type() == MIRType::Int32);
+  MOZ_ASSERT(rhs->type() == MIRType::Int32);
+
+  LUrshD* lir = new (alloc())
+      LUrshD(useRegister(lhs), useRegisterOrConstant(rhs), temp());
+  define(lir, mir);
+}
+
+void LIRGeneratorARM64::lowerPowOfTwoI(MPow* mir) {
+  int32_t base = mir->input()->toConstant()->toInt32();
+  MDefinition* power = mir->power();
+
+  auto* lir = new (alloc()) LPowOfTwoI(useRegister(power), base);
+  assignSnapshot(lir, mir->bailoutKind());
+  define(lir, mir);
+}
+
+void LIRGeneratorARM64::lowerBigIntLsh(MBigIntLsh* ins) {
+  auto* lir = new (alloc()) LBigIntLsh(
+      useRegister(ins->lhs()), useRegister(ins->rhs()), temp(), temp(), temp());
+  define(lir, ins);
+  assignSafepoint(lir, ins);
+}
+
+void LIRGeneratorARM64::lowerBigIntRsh(MBigIntRsh* ins) {
+  auto* lir = new (alloc()) LBigIntRsh(
+      useRegister(ins->lhs()), useRegister(ins->rhs()), temp(), temp(), temp());
+  define(lir, ins);
+  assignSafepoint(lir, ins);
+}
+
+void LIRGeneratorARM64::lowerBigIntDiv(MBigIntDiv* ins) {
+  auto* lir = new (alloc()) LBigIntDiv(useRegister(ins->lhs()),
+                                       useRegister(ins->rhs()), temp(), temp());
+  define(lir, ins);
+  assignSafepoint(lir, ins);
+}
+
+void LIRGeneratorARM64::lowerBigIntMod(MBigIntMod* ins) {
+  auto* lir = new (alloc()) LBigIntMod(useRegister(ins->lhs()),
+                                       useRegister(ins->rhs()), temp(), temp());
+  define(lir, ins);
+  assignSafepoint(lir, ins);
+}
+
+#ifdef ENABLE_WASM_SIMD
+
+bool LIRGeneratorARM64::canFoldReduceSimd128AndBranch(wasm::SimdOp op) {
+  switch (op) {
+    case wasm::SimdOp::V128AnyTrue:
+    case wasm::SimdOp::I8x16AllTrue:
+    case wasm::SimdOp::I16x8AllTrue:
+    case wasm::SimdOp::I32x4AllTrue:
+    case wasm::SimdOp::I64x2AllTrue:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool LIRGeneratorARM64::canEmitWasmReduceSimd128AtUses(
+    MWasmReduceSimd128* ins) {
+  if (!ins->canEmitAtUses()) {
+    return false;
+  }
+  // Only specific ops generating int32.
+  if (ins->type() != MIRType::Int32) {
+    return false;
+  }
+  if (!canFoldReduceSimd128AndBranch(ins->simdOp())) {
+    return false;
+  }
+  // If never used then defer (it will be removed).
+  MUseIterator iter(ins->usesBegin());
+  if (iter == ins->usesEnd()) {
+    return true;
+  }
+  // We require an MTest consumer.
+  MNode* node = iter->consumer();
+  if (!node->isDefinition() || !node->toDefinition()->isTest()) {
+    return false;
+  }
+  // Defer only if there's only one use.
+  iter++;
+  return iter == ins->usesEnd();
+}
+
+#endif
+
+void LIRGenerator::visitWasmNeg(MWasmNeg* ins) {
+  switch (ins->type()) {
+    case MIRType::Int32:
+      define(new (alloc()) LNegI(useRegisterAtStart(ins->input())), ins);
+      break;
+    case MIRType::Float32:
+      define(new (alloc()) LNegF(useRegisterAtStart(ins->input())), ins);
+      break;
+    case MIRType::Double:
+      define(new (alloc()) LNegD(useRegisterAtStart(ins->input())), ins);
+      break;
+    default:
+      MOZ_CRASH("unexpected type");
+  }
+}
+
+void LIRGeneratorARM64::lowerUDiv(MDiv* div) {
+  LAllocation lhs = useRegister(div->lhs());
+  if (div->rhs()->isConstant()) {
+    // NOTE: the result of toInt32 is coerced to uint32_t.
+    uint32_t rhs = div->rhs()->toConstant()->toInt32();
+    int32_t shift = mozilla::FloorLog2(rhs);
+
+    if (rhs != 0 && uint32_t(1) << shift == rhs) {
+      LDivPowTwoI* lir = new (alloc()) LDivPowTwoI(lhs, shift, false);
+      if (div->fallible()) {
+        assignSnapshot(lir, div->bailoutKind());
+      }
+      define(lir, div);
+      return;
+    }
+
+    LUDivConstantI* lir = new (alloc()) LUDivConstantI(lhs, rhs, temp());
+    if (div->fallible()) {
+      assignSnapshot(lir, div->bailoutKind());
+    }
+    define(lir, div);
+    return;
+  }
+
+  // Generate UDiv
+  LAllocation rhs = useRegister(div->rhs());
+  LDefinition remainder = LDefinition::BogusTemp();
+  if (!div->canTruncateRemainder()) {
+    remainder = temp();
+  }
+
+  LUDiv* lir = new (alloc()) LUDiv(lhs, rhs, remainder);
+  if (div->fallible()) {
+    assignSnapshot(lir, div->bailoutKind());
+  }
+  define(lir, div);
+}
+
+void LIRGeneratorARM64::lowerUMod(MMod* mod) {
+  LUMod* lir = new (alloc())
+      LUMod(useRegister(mod->getOperand(0)), useRegister(mod->getOperand(1)));
+  if (mod->fallible()) {
+    assignSnapshot(lir, mod->bailoutKind());
+  }
+  define(lir, mod);
+}
+
+void LIRGenerator::visitWasmUnsignedToDouble(MWasmUnsignedToDouble* ins) {
+  MOZ_ASSERT(ins->input()->type() == MIRType::Int32);
+  LWasmUint32ToDouble* lir =
+      new (alloc()) LWasmUint32ToDouble(useRegisterAtStart(ins->input()));
+  define(lir, ins);
+}
+
+void LIRGenerator::visitWasmUnsignedToFloat32(MWasmUnsignedToFloat32* ins) {
+  MOZ_ASSERT(ins->input()->type() == MIRType::Int32);
+  LWasmUint32ToFloat32* lir =
+      new (alloc()) LWasmUint32ToFloat32(useRegisterAtStart(ins->input()));
+  define(lir, ins);
+}
+
+void LIRGenerator::visitAsmJSLoadHeap(MAsmJSLoadHeap* ins) {
+  MDefinition* base = ins->base();
+  MOZ_ASSERT(base->type() == MIRType::Int32);
+
+  MDefinition* boundsCheckLimit = ins->boundsCheckLimit();
+  MOZ_ASSERT_IF(ins->needsBoundsCheck(),
+                boundsCheckLimit->type() == MIRType::Int32);
+
+  LAllocation baseAlloc = useRegisterAtStart(base);
+
+  LAllocation limitAlloc = ins->needsBoundsCheck()
+                               ? useRegisterAtStart(boundsCheckLimit)
+                               : LAllocation();
+
+  // We have no memory-base value, meaning that HeapReg is to be used as the
+  // memory base.  This follows from the definition of
+  // FunctionCompiler::maybeLoadMemoryBase() in WasmIonCompile.cpp.
+  MOZ_ASSERT(!ins->hasMemoryBase());
+  auto* lir =
+      new (alloc()) LAsmJSLoadHeap(baseAlloc, limitAlloc, LAllocation());
+  define(lir, ins);
+}
+
+void LIRGenerator::visitAsmJSStoreHeap(MAsmJSStoreHeap* ins) {
+  MDefinition* base = ins->base();
+  MOZ_ASSERT(base->type() == MIRType::Int32);
+
+  MDefinition* boundsCheckLimit = ins->boundsCheckLimit();
+  MOZ_ASSERT_IF(ins->needsBoundsCheck(),
+                boundsCheckLimit->type() == MIRType::Int32);
+
+  LAllocation baseAlloc = useRegisterAtStart(base);
+
+  LAllocation limitAlloc = ins->needsBoundsCheck()
+                               ? useRegisterAtStart(boundsCheckLimit)
+                               : LAllocation();
+
+  // See comment in LIRGenerator::visitAsmJSStoreHeap just above.
+  MOZ_ASSERT(!ins->hasMemoryBase());
+  add(new (alloc()) LAsmJSStoreHeap(baseAlloc, useRegisterAtStart(ins->value()),
+                                    limitAlloc, LAllocation()),
+      ins);
+}
+
+void LIRGenerator::visitWasmCompareExchangeHeap(MWasmCompareExchangeHeap* ins) {
+  MDefinition* base = ins->base();
+  // See comment in visitWasmLoad re the type of 'base'.
+  MOZ_ASSERT(base->type() == MIRType::Int32 || base->type() == MIRType::Int64);
+
+  // Note, the access type may be Int64 here.
+
+  LWasmCompareExchangeHeap* lir = new (alloc())
+      LWasmCompareExchangeHeap(useRegister(base), useRegister(ins->oldValue()),
+                               useRegister(ins->newValue()));
+
+  define(lir, ins);
+}
+
+void LIRGenerator::visitWasmAtomicExchangeHeap(MWasmAtomicExchangeHeap* ins) {
+  MDefinition* base = ins->base();
+  // See comment in visitWasmLoad re the type of 'base'.
+  MOZ_ASSERT(base->type() == MIRType::Int32 || base->type() == MIRType::Int64);
+
+  // Note, the access type may be Int64 here.
+
+  LWasmAtomicExchangeHeap* lir = new (alloc())
+      LWasmAtomicExchangeHeap(useRegister(base), useRegister(ins->value()));
+  define(lir, ins);
+}
+
+void LIRGenerator::visitWasmAtomicBinopHeap(MWasmAtomicBinopHeap* ins) {
+  MDefinition* base = ins->base();
+  // See comment in visitWasmLoad re the type of 'base'.
+  MOZ_ASSERT(base->type() == MIRType::Int32 || base->type() == MIRType::Int64);
+
+  // Note, the access type may be Int64 here.
+
+  if (!ins->hasUses()) {
+    LWasmAtomicBinopHeapForEffect* lir =
+        new (alloc()) LWasmAtomicBinopHeapForEffect(useRegister(base),
+                                                    useRegister(ins->value()),
+                                                    /* flagTemp= */ temp());
+    add(lir, ins);
+    return;
+  }
+
+  LWasmAtomicBinopHeap* lir = new (alloc())
+      LWasmAtomicBinopHeap(useRegister(base), useRegister(ins->value()),
+                           /* temp= */ LDefinition::BogusTemp(),
+                           /* flagTemp= */ temp());
+  define(lir, ins);
+}
+
+void LIRGeneratorARM64::lowerTruncateDToInt32(MTruncateToInt32* ins) {
+  MDefinition* opd = ins->input();
+  MOZ_ASSERT(opd->type() == MIRType::Double);
+  define(new (alloc())
+             LTruncateDToInt32(useRegister(opd), LDefinition::BogusTemp()),
+         ins);
+}
+
+void LIRGeneratorARM64::lowerTruncateFToInt32(MTruncateToInt32* ins) {
+  MDefinition* opd = ins->input();
+  MOZ_ASSERT(opd->type() == MIRType::Float32);
+  define(new (alloc())
+             LTruncateFToInt32(useRegister(opd), LDefinition::BogusTemp()),
+         ins);
+}
+
+void LIRGenerator::visitAtomicTypedArrayElementBinop(
+    MAtomicTypedArrayElementBinop* ins) {
+  MOZ_ASSERT(ins->arrayType() != Scalar::Uint8Clamped);
+  MOZ_ASSERT(ins->arrayType() != Scalar::Float32);
+  MOZ_ASSERT(ins->arrayType() != Scalar::Float64);
+
+  MOZ_ASSERT(ins->elements()->type() == MIRType::Elements);
+  MOZ_ASSERT(ins->index()->type() == MIRType::IntPtr);
+
+  const LUse elements = useRegister(ins->elements());
+  const LAllocation index =
+      useRegisterOrIndexConstant(ins->index(), ins->arrayType());
+
+  LAllocation value = useRegister(ins->value());
+
+  if (Scalar::isBigIntType(ins->arrayType())) {
+    LInt64Definition temp1 = tempInt64();
+    LInt64Definition temp2 = tempInt64();
+
+    // Case 1: the result of the operation is not used.
+    //
+    // We can omit allocating the result BigInt.
+
+    if (ins->isForEffect()) {
+      auto* lir = new (alloc()) LAtomicTypedArrayElementBinopForEffect64(
+          elements, index, value, temp1, temp2);
+      add(lir, ins);
+      return;
+    }
+
+    // Case 2: the result of the operation is used.
+
+    auto* lir = new (alloc())
+        LAtomicTypedArrayElementBinop64(elements, index, value, temp1, temp2);
+    define(lir, ins);
+    assignSafepoint(lir, ins);
+    return;
+  }
+
+  if (ins->isForEffect()) {
+    auto* lir = new (alloc())
+        LAtomicTypedArrayElementBinopForEffect(elements, index, value, temp());
+    add(lir, ins);
+    return;
+  }
+
+  LDefinition tempDef1 = temp();
+  LDefinition tempDef2 = LDefinition::BogusTemp();
+  if (ins->arrayType() == Scalar::Uint32) {
+    tempDef2 = temp();
+  }
+
+  LAtomicTypedArrayElementBinop* lir = new (alloc())
+      LAtomicTypedArrayElementBinop(elements, index, value, tempDef1, tempDef2);
+
+  define(lir, ins);
+}
+
+void LIRGenerator::visitCompareExchangeTypedArrayElement(
+    MCompareExchangeTypedArrayElement* ins) {
+  MOZ_ASSERT(ins->arrayType() != Scalar::Float32);
+  MOZ_ASSERT(ins->arrayType() != Scalar::Float64);
+
+  MOZ_ASSERT(ins->elements()->type() == MIRType::Elements);
+  MOZ_ASSERT(ins->index()->type() == MIRType::IntPtr);
+
+  const LUse elements = useRegister(ins->elements());
+  const LAllocation index =
+      useRegisterOrIndexConstant(ins->index(), ins->arrayType());
+
+  const LAllocation newval = useRegister(ins->newval());
+  const LAllocation oldval = useRegister(ins->oldval());
+
+  if (Scalar::isBigIntType(ins->arrayType())) {
+    LInt64Definition temp1 = tempInt64();
+    LInt64Definition temp2 = tempInt64();
+
+    auto* lir = new (alloc()) LCompareExchangeTypedArrayElement64(
+        elements, index, oldval, newval, temp1, temp2);
+    define(lir, ins);
+    assignSafepoint(lir, ins);
+    return;
+  }
+
+  // If the target is an FPReg then we need a temporary at the CodeGenerator
+  // level for creating the result.
+
+  LDefinition outTemp = LDefinition::BogusTemp();
+  if (ins->arrayType() == Scalar::Uint32) {
+    outTemp = temp();
+  }
+
+  LCompareExchangeTypedArrayElement* lir =
+      new (alloc()) LCompareExchangeTypedArrayElement(elements, index, oldval,
+                                                      newval, outTemp);
+
+  define(lir, ins);
+}
+
+void LIRGenerator::visitAtomicExchangeTypedArrayElement(
+    MAtomicExchangeTypedArrayElement* ins) {
+  MOZ_ASSERT(ins->elements()->type() == MIRType::Elements);
+  MOZ_ASSERT(ins->index()->type() == MIRType::IntPtr);
+
+  const LUse elements = useRegister(ins->elements());
+  const LAllocation index =
+      useRegisterOrIndexConstant(ins->index(), ins->arrayType());
+
+  const LAllocation value = useRegister(ins->value());
+
+  if (Scalar::isBigIntType(ins->arrayType())) {
+    LInt64Definition temp1 = tempInt64();
+    LDefinition temp2 = temp();
+
+    auto* lir = new (alloc()) LAtomicExchangeTypedArrayElement64(
+        elements, index, value, temp1, temp2);
+    define(lir, ins);
+    assignSafepoint(lir, ins);
+    return;
+  }
+
+  MOZ_ASSERT(ins->arrayType() <= Scalar::Uint32);
+
+  LDefinition tempDef = LDefinition::BogusTemp();
+  if (ins->arrayType() == Scalar::Uint32) {
+    tempDef = temp();
+  }
+
+  LAtomicExchangeTypedArrayElement* lir = new (alloc())
+      LAtomicExchangeTypedArrayElement(elements, index, value, tempDef);
+
+  define(lir, ins);
+}
+
+void LIRGeneratorARM64::lowerAtomicLoad64(MLoadUnboxedScalar* ins) {
+  const LUse elements = useRegister(ins->elements());
+  const LAllocation index =
+      useRegisterOrIndexConstant(ins->index(), ins->storageType());
+
+  auto* lir = new (alloc()) LAtomicLoad64(elements, index, temp(), tempInt64());
+  define(lir, ins);
+  assignSafepoint(lir, ins);
+}
+
+void LIRGeneratorARM64::lowerAtomicStore64(MStoreUnboxedScalar* ins) {
+  LUse elements = useRegister(ins->elements());
+  LAllocation index =
+      useRegisterOrIndexConstant(ins->index(), ins->writeType());
+  LAllocation value = useRegister(ins->value());
+
+  add(new (alloc()) LAtomicStore64(elements, index, value, tempInt64()), ins);
+}
+
+void LIRGenerator::visitSubstr(MSubstr* ins) {
+  LSubstr* lir = new (alloc())
+      LSubstr(useRegister(ins->string()), useRegister(ins->begin()),
+              useRegister(ins->length()), temp(), temp(), temp());
+  define(lir, ins);
+  assignSafepoint(lir, ins);
+}
+
+void LIRGenerator::visitWasmTruncateToInt64(MWasmTruncateToInt64* ins) {
+  MDefinition* opd = ins->input();
+  MOZ_ASSERT(opd->type() == MIRType::Double || opd->type() == MIRType::Float32);
+
+  defineInt64(new (alloc()) LWasmTruncateToInt64(useRegister(opd)), ins);
+}
+
+void LIRGeneratorARM64::lowerWasmBuiltinTruncateToInt64(
+    MWasmBuiltinTruncateToInt64* ins) {
+  MOZ_CRASH("We don't use WasmBuiltinTruncateToInt64 for arm64");
+}
+
+void LIRGeneratorARM64::lowerBuiltinInt64ToFloatingPoint(
+    MBuiltinInt64ToFloatingPoint* ins) {
+  MOZ_CRASH("We don't use it for this architecture");
+}
+
+void LIRGenerator::visitWasmHeapBase(MWasmHeapBase* ins) {
+  auto* lir = new (alloc()) LWasmHeapBase(LAllocation());
+  define(lir, ins);
+}
+
+void LIRGenerator::visitWasmLoad(MWasmLoad* ins) {
+  MDefinition* base = ins->base();
+  // 'base' is a GPR but may be of either type.  If it is 32-bit it is
+  // zero-extended and can act as 64-bit.
+  MOZ_ASSERT(base->type() == MIRType::Int32 || base->type() == MIRType::Int64);
+
+  LAllocation ptr = useRegisterOrConstantAtStart(base);
+
+  if (ins->type() == MIRType::Int64) {
+    auto* lir = new (alloc()) LWasmLoadI64(ptr);
+    defineInt64(lir, ins);
+  } else {
+    auto* lir = new (alloc()) LWasmLoad(ptr);
+    define(lir, ins);
+  }
+}
+
+void LIRGenerator::visitWasmStore(MWasmStore* ins) {
+  MDefinition* base = ins->base();
+  // See comment in visitWasmLoad re the type of 'base'.
+  MOZ_ASSERT(base->type() == MIRType::Int32 || base->type() == MIRType::Int64);
+
+  MDefinition* value = ins->value();
+
+  if (ins->access().type() == Scalar::Int64) {
+    LAllocation baseAlloc = useRegisterOrConstantAtStart(base);
+    LInt64Allocation valueAlloc = useInt64RegisterAtStart(value);
+    auto* lir = new (alloc()) LWasmStoreI64(baseAlloc, valueAlloc);
+    add(lir, ins);
+    return;
+  }
+
+  LAllocation baseAlloc = useRegisterOrConstantAtStart(base);
+  LAllocation valueAlloc = useRegisterAtStart(value);
+  auto* lir = new (alloc()) LWasmStore(baseAlloc, valueAlloc);
+  add(lir, ins);
+}
+
+void LIRGenerator::visitInt64ToFloatingPoint(MInt64ToFloatingPoint* ins) {
+  MDefinition* opd = ins->input();
+  MOZ_ASSERT(opd->type() == MIRType::Int64);
+  MOZ_ASSERT(IsFloatingPointType(ins->type()));
+
+  define(new (alloc()) LInt64ToFloatingPoint(useInt64Register(opd)), ins);
+}
+
+void LIRGenerator::visitCopySign(MCopySign* ins) {
+  MDefinition* lhs = ins->lhs();
+  MDefinition* rhs = ins->rhs();
+
+  MOZ_ASSERT(IsFloatingPointType(lhs->type()));
+  MOZ_ASSERT(lhs->type() == rhs->type());
+  MOZ_ASSERT(lhs->type() == ins->type());
+
+  LInstructionHelper<1, 2, 2>* lir;
+  if (lhs->type() == MIRType::Double) {
+    lir = new (alloc()) LCopySignD();
+  } else {
+    lir = new (alloc()) LCopySignF();
+  }
+
+  lir->setOperand(0, useRegisterAtStart(lhs));
+  lir->setOperand(1, willHaveDifferentLIRNodes(lhs, rhs)
+                         ? useRegister(rhs)
+                         : useRegisterAtStart(rhs));
+  // The copySignDouble and copySignFloat32 are optimized for lhs == output.
+  // It also prevents rhs == output when lhs != output, avoids clobbering.
+  defineReuseInput(lir, ins, 0);
+}
+
+void LIRGenerator::visitExtendInt32ToInt64(MExtendInt32ToInt64* ins) {
+  defineInt64(
+      new (alloc()) LExtendInt32ToInt64(useRegisterAtStart(ins->input())), ins);
+}
+
+void LIRGenerator::visitSignExtendInt64(MSignExtendInt64* ins) {
+  defineInt64(new (alloc())
+                  LSignExtendInt64(useInt64RegisterAtStart(ins->input())),
+              ins);
+}
+
+void LIRGenerator::visitWasmTernarySimd128(MWasmTernarySimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  MOZ_ASSERT(ins->v0()->type() == MIRType::Simd128);
+  MOZ_ASSERT(ins->v1()->type() == MIRType::Simd128);
+  MOZ_ASSERT(ins->v2()->type() == MIRType::Simd128);
+  MOZ_ASSERT(ins->type() == MIRType::Simd128);
+
+  switch (ins->simdOp()) {
+    case wasm::SimdOp::V128Bitselect: {
+      auto* lir = new (alloc()) LWasmTernarySimd128(
+          ins->simdOp(), useRegister(ins->v0()), useRegister(ins->v1()),
+          useRegisterAtStart(ins->v2()));
+      // On ARM64, control register is used as output at machine instruction.
+      defineReuseInput(lir, ins, LWasmTernarySimd128::V2);
+      break;
+    }
+    case wasm::SimdOp::F32x4RelaxedFma:
+    case wasm::SimdOp::F32x4RelaxedFnma:
+    case wasm::SimdOp::F64x2RelaxedFma:
+    case wasm::SimdOp::F64x2RelaxedFnma: {
+      auto* lir = new (alloc()) LWasmTernarySimd128(
+          ins->simdOp(), useRegister(ins->v0()), useRegister(ins->v1()),
+          useRegisterAtStart(ins->v2()));
+      defineReuseInput(lir, ins, LWasmTernarySimd128::V2);
+      break;
+    }
+    case wasm::SimdOp::I32x4DotI8x16I7x16AddS: {
+      auto* lir = new (alloc()) LWasmTernarySimd128(
+          ins->simdOp(), useRegister(ins->v0()), useRegister(ins->v1()),
+          useRegisterAtStart(ins->v2()), tempSimd128());
+      defineReuseInput(lir, ins, LWasmTernarySimd128::V2);
+      break;
+    }
+    case wasm::SimdOp::I8x16RelaxedLaneSelect:
+    case wasm::SimdOp::I16x8RelaxedLaneSelect:
+    case wasm::SimdOp::I32x4RelaxedLaneSelect:
+    case wasm::SimdOp::I64x2RelaxedLaneSelect: {
+      auto* lir = new (alloc()) LWasmTernarySimd128(
+          ins->simdOp(), useRegister(ins->v0()), useRegister(ins->v1()),
+          useRegisterAtStart(ins->v2()));
+      defineReuseInput(lir, ins, LWasmTernarySimd128::V2);
+      break;
+    }
+    default:
+      MOZ_CRASH("NYI");
+  }
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+void LIRGenerator::visitWasmBinarySimd128(MWasmBinarySimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  MDefinition* lhs = ins->lhs();
+  MDefinition* rhs = ins->rhs();
+  wasm::SimdOp op = ins->simdOp();
+
+  MOZ_ASSERT(lhs->type() == MIRType::Simd128);
+  MOZ_ASSERT(rhs->type() == MIRType::Simd128);
+  MOZ_ASSERT(ins->type() == MIRType::Simd128);
+
+  LAllocation lhsAlloc = useRegisterAtStart(lhs);
+  LAllocation rhsAlloc = useRegisterAtStart(rhs);
+  LDefinition tempReg0 = LDefinition::BogusTemp();
+  LDefinition tempReg1 = LDefinition::BogusTemp();
+  if (op == wasm::SimdOp::I64x2Mul) {
+    tempReg0 = tempSimd128();
+    tempReg1 = tempSimd128();
+  }
+  auto* lir = new (alloc())
+      LWasmBinarySimd128(op, lhsAlloc, rhsAlloc, tempReg0, tempReg1);
+  define(lir, ins);
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+#ifdef ENABLE_WASM_SIMD
+bool MWasmTernarySimd128::specializeBitselectConstantMaskAsShuffle(
+    int8_t shuffle[16]) {
+  return false;
+}
+bool MWasmTernarySimd128::canRelaxBitselect() { return false; }
+
+bool MWasmBinarySimd128::canPmaddubsw() { return false; }
+#endif
+
+bool MWasmBinarySimd128::specializeForConstantRhs() {
+  // Probably many we want to do here
+  return false;
+}
+
+void LIRGenerator::visitWasmBinarySimd128WithConstant(
+    MWasmBinarySimd128WithConstant* ins) {
+  MOZ_CRASH("binary SIMD with constant NYI");
+}
+
+void LIRGenerator::visitWasmShiftSimd128(MWasmShiftSimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  MDefinition* lhs = ins->lhs();
+  MDefinition* rhs = ins->rhs();
+
+  MOZ_ASSERT(lhs->type() == MIRType::Simd128);
+  MOZ_ASSERT(rhs->type() == MIRType::Int32);
+  MOZ_ASSERT(ins->type() == MIRType::Simd128);
+
+  if (rhs->isConstant()) {
+    int32_t shiftCount = rhs->toConstant()->toInt32();
+    switch (ins->simdOp()) {
+      case wasm::SimdOp::I8x16Shl:
+      case wasm::SimdOp::I8x16ShrU:
+      case wasm::SimdOp::I8x16ShrS:
+        shiftCount &= 7;
+        break;
+      case wasm::SimdOp::I16x8Shl:
+      case wasm::SimdOp::I16x8ShrU:
+      case wasm::SimdOp::I16x8ShrS:
+        shiftCount &= 15;
+        break;
+      case wasm::SimdOp::I32x4Shl:
+      case wasm::SimdOp::I32x4ShrU:
+      case wasm::SimdOp::I32x4ShrS:
+        shiftCount &= 31;
+        break;
+      case wasm::SimdOp::I64x2Shl:
+      case wasm::SimdOp::I64x2ShrU:
+      case wasm::SimdOp::I64x2ShrS:
+        shiftCount &= 63;
+        break;
+      default:
+        MOZ_CRASH("Unexpected shift operation");
+    }
+#  ifdef DEBUG
+    js::wasm::ReportSimdAnalysis("shift -> constant shift");
+#  endif
+    auto* lir = new (alloc())
+        LWasmConstantShiftSimd128(useRegisterAtStart(lhs), shiftCount);
+    define(lir, ins);
+    return;
+  }
+
+#  ifdef DEBUG
+  js::wasm::ReportSimdAnalysis("shift -> variable shift");
+#  endif
+
+  LAllocation lhsDestAlloc = useRegisterAtStart(lhs);
+  LAllocation rhsAlloc = useRegisterAtStart(rhs);
+  auto* lir = new (alloc()) LWasmVariableShiftSimd128(lhsDestAlloc, rhsAlloc,
+                                                      LDefinition::BogusTemp());
+  define(lir, ins);
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+void LIRGenerator::visitWasmShuffleSimd128(MWasmShuffleSimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  MOZ_ASSERT(ins->lhs()->type() == MIRType::Simd128);
+  MOZ_ASSERT(ins->rhs()->type() == MIRType::Simd128);
+  MOZ_ASSERT(ins->type() == MIRType::Simd128);
+
+  SimdShuffle s = ins->shuffle();
+  switch (s.opd) {
+    case SimdShuffle::Operand::LEFT:
+    case SimdShuffle::Operand::RIGHT: {
+      LAllocation src;
+      switch (*s.permuteOp) {
+        case SimdPermuteOp::MOVE:
+        case SimdPermuteOp::BROADCAST_8x16:
+        case SimdPermuteOp::BROADCAST_16x8:
+        case SimdPermuteOp::PERMUTE_8x16:
+        case SimdPermuteOp::PERMUTE_16x8:
+        case SimdPermuteOp::PERMUTE_32x4:
+        case SimdPermuteOp::ROTATE_RIGHT_8x16:
+        case SimdPermuteOp::SHIFT_LEFT_8x16:
+        case SimdPermuteOp::SHIFT_RIGHT_8x16:
+        case SimdPermuteOp::REVERSE_16x8:
+        case SimdPermuteOp::REVERSE_32x4:
+        case SimdPermuteOp::REVERSE_64x2:
+          break;
+        default:
+          MOZ_CRASH("Unexpected operator");
+      }
+      if (s.opd == SimdShuffle::Operand::LEFT) {
+        src = useRegisterAtStart(ins->lhs());
+      } else {
+        src = useRegisterAtStart(ins->rhs());
+      }
+      auto* lir =
+          new (alloc()) LWasmPermuteSimd128(src, *s.permuteOp, s.control);
+      define(lir, ins);
+      break;
+    }
+    case SimdShuffle::Operand::BOTH:
+    case SimdShuffle::Operand::BOTH_SWAPPED: {
+      LDefinition temp = LDefinition::BogusTemp();
+      LAllocation lhs;
+      LAllocation rhs;
+      if (s.opd == SimdShuffle::Operand::BOTH) {
+        lhs = useRegisterAtStart(ins->lhs());
+        rhs = useRegisterAtStart(ins->rhs());
+      } else {
+        lhs = useRegisterAtStart(ins->rhs());
+        rhs = useRegisterAtStart(ins->lhs());
+      }
+      auto* lir = new (alloc())
+          LWasmShuffleSimd128(lhs, rhs, temp, *s.shuffleOp, s.control);
+      define(lir, ins);
+      break;
+    }
+  }
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+void LIRGenerator::visitWasmReplaceLaneSimd128(MWasmReplaceLaneSimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  MOZ_ASSERT(ins->lhs()->type() == MIRType::Simd128);
+  MOZ_ASSERT(ins->type() == MIRType::Simd128);
+
+  // Optimal code generation reuses the lhs register because the rhs scalar is
+  // merged into a vector lhs.
+  LAllocation lhs = useRegisterAtStart(ins->lhs());
+  if (ins->rhs()->type() == MIRType::Int64) {
+    auto* lir = new (alloc())
+        LWasmReplaceInt64LaneSimd128(lhs, useInt64Register(ins->rhs()));
+    defineReuseInput(lir, ins, 0);
+  } else {
+    auto* lir =
+        new (alloc()) LWasmReplaceLaneSimd128(lhs, useRegister(ins->rhs()));
+    defineReuseInput(lir, ins, 0);
+  }
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+void LIRGenerator::visitWasmScalarToSimd128(MWasmScalarToSimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  MOZ_ASSERT(ins->type() == MIRType::Simd128);
+
+  switch (ins->input()->type()) {
+    case MIRType::Int64: {
+      // 64-bit integer splats.
+      // Load-and-(sign|zero)extend.
+      auto* lir = new (alloc())
+          LWasmInt64ToSimd128(useInt64RegisterAtStart(ins->input()));
+      define(lir, ins);
+      break;
+    }
+    case MIRType::Float32:
+    case MIRType::Double: {
+      // Floating-point splats.
+      auto* lir =
+          new (alloc()) LWasmScalarToSimd128(useRegisterAtStart(ins->input()));
+      define(lir, ins);
+      break;
+    }
+    default: {
+      // 32-bit integer splats.
+      auto* lir =
+          new (alloc()) LWasmScalarToSimd128(useRegisterAtStart(ins->input()));
+      define(lir, ins);
+      break;
+    }
+  }
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+void LIRGenerator::visitWasmUnarySimd128(MWasmUnarySimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  MOZ_ASSERT(ins->input()->type() == MIRType::Simd128);
+  MOZ_ASSERT(ins->type() == MIRType::Simd128);
+
+  LDefinition tempReg = LDefinition::BogusTemp();
+  switch (ins->simdOp()) {
+    case wasm::SimdOp::I8x16Neg:
+    case wasm::SimdOp::I16x8Neg:
+    case wasm::SimdOp::I32x4Neg:
+    case wasm::SimdOp::I64x2Neg:
+    case wasm::SimdOp::F32x4Neg:
+    case wasm::SimdOp::F64x2Neg:
+    case wasm::SimdOp::F32x4Abs:
+    case wasm::SimdOp::F64x2Abs:
+    case wasm::SimdOp::V128Not:
+    case wasm::SimdOp::F32x4Sqrt:
+    case wasm::SimdOp::F64x2Sqrt:
+    case wasm::SimdOp::I8x16Abs:
+    case wasm::SimdOp::I16x8Abs:
+    case wasm::SimdOp::I32x4Abs:
+    case wasm::SimdOp::I64x2Abs:
+    case wasm::SimdOp::I32x4TruncSatF32x4S:
+    case wasm::SimdOp::F32x4ConvertI32x4U:
+    case wasm::SimdOp::I32x4TruncSatF32x4U:
+    case wasm::SimdOp::I16x8ExtendLowI8x16S:
+    case wasm::SimdOp::I16x8ExtendHighI8x16S:
+    case wasm::SimdOp::I16x8ExtendLowI8x16U:
+    case wasm::SimdOp::I16x8ExtendHighI8x16U:
+    case wasm::SimdOp::I32x4ExtendLowI16x8S:
+    case wasm::SimdOp::I32x4ExtendHighI16x8S:
+    case wasm::SimdOp::I32x4ExtendLowI16x8U:
+    case wasm::SimdOp::I32x4ExtendHighI16x8U:
+    case wasm::SimdOp::I64x2ExtendLowI32x4S:
+    case wasm::SimdOp::I64x2ExtendHighI32x4S:
+    case wasm::SimdOp::I64x2ExtendLowI32x4U:
+    case wasm::SimdOp::I64x2ExtendHighI32x4U:
+    case wasm::SimdOp::F32x4ConvertI32x4S:
+    case wasm::SimdOp::F32x4Ceil:
+    case wasm::SimdOp::F32x4Floor:
+    case wasm::SimdOp::F32x4Trunc:
+    case wasm::SimdOp::F32x4Nearest:
+    case wasm::SimdOp::F64x2Ceil:
+    case wasm::SimdOp::F64x2Floor:
+    case wasm::SimdOp::F64x2Trunc:
+    case wasm::SimdOp::F64x2Nearest:
+    case wasm::SimdOp::F32x4DemoteF64x2Zero:
+    case wasm::SimdOp::F64x2PromoteLowF32x4:
+    case wasm::SimdOp::F64x2ConvertLowI32x4S:
+    case wasm::SimdOp::F64x2ConvertLowI32x4U:
+    case wasm::SimdOp::I16x8ExtaddPairwiseI8x16S:
+    case wasm::SimdOp::I16x8ExtaddPairwiseI8x16U:
+    case wasm::SimdOp::I32x4ExtaddPairwiseI16x8S:
+    case wasm::SimdOp::I32x4ExtaddPairwiseI16x8U:
+    case wasm::SimdOp::I8x16Popcnt:
+    case wasm::SimdOp::I32x4RelaxedTruncF32x4S:
+    case wasm::SimdOp::I32x4RelaxedTruncF32x4U:
+    case wasm::SimdOp::I32x4RelaxedTruncF64x2SZero:
+    case wasm::SimdOp::I32x4RelaxedTruncF64x2UZero:
+      break;
+    case wasm::SimdOp::I32x4TruncSatF64x2SZero:
+    case wasm::SimdOp::I32x4TruncSatF64x2UZero:
+      tempReg = tempSimd128();
+      break;
+    default:
+      MOZ_CRASH("Unary SimdOp not implemented");
+  }
+
+  LUse input = useRegisterAtStart(ins->input());
+  LWasmUnarySimd128* lir = new (alloc()) LWasmUnarySimd128(input, tempReg);
+  define(lir, ins);
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+void LIRGenerator::visitWasmReduceSimd128(MWasmReduceSimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  if (canEmitWasmReduceSimd128AtUses(ins)) {
+    emitAtUses(ins);
+    return;
+  }
+
+  // Reductions (any_true, all_true, bitmask, extract_lane) uniformly prefer
+  // useRegisterAtStart:
+  //
+  // - In most cases, the input type differs from the output type, so there's no
+  //   conflict and it doesn't really matter.
+  //
+  // - For extract_lane(0) on F32x4 and F64x2, input == output results in zero
+  //   code being generated.
+  //
+  // - For extract_lane(k > 0) on F32x4 and F64x2, allowing the input register
+  //   to be targeted lowers register pressure if it's the last use of the
+  //   input.
+
+  if (ins->type() == MIRType::Int64) {
+    auto* lir = new (alloc())
+        LWasmReduceSimd128ToInt64(useRegisterAtStart(ins->input()));
+    defineInt64(lir, ins);
+  } else {
+    LDefinition tempReg = LDefinition::BogusTemp();
+    switch (ins->simdOp()) {
+      case wasm::SimdOp::I8x16Bitmask:
+      case wasm::SimdOp::I16x8Bitmask:
+      case wasm::SimdOp::I32x4Bitmask:
+      case wasm::SimdOp::I64x2Bitmask:
+        tempReg = tempSimd128();
+        break;
+      default:
+        break;
+    }
+
+    // Ideally we would reuse the input register for floating extract_lane if
+    // the lane is zero, but constraints in the register allocator require the
+    // input and output register types to be the same.
+    auto* lir = new (alloc())
+        LWasmReduceSimd128(useRegisterAtStart(ins->input()), tempReg);
+    define(lir, ins);
+  }
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+void LIRGenerator::visitWasmLoadLaneSimd128(MWasmLoadLaneSimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  // On 64-bit systems, the base pointer can be 32 bits or 64 bits.  Either way,
+  // it fits in a GPR so we can ignore the Register/Register64 distinction here.
+
+  // Optimal allocation here reuses the value input for the output register
+  // because codegen otherwise has to copy the input to the output; this is
+  // because load-lane is implemented as load + replace-lane.  Bug 1706106 may
+  // change all of that, so leave it alone for now.
+  LUse base = useRegisterAtStart(ins->base());
+  LUse inputUse = useRegisterAtStart(ins->value());
+  MOZ_ASSERT(!ins->hasMemoryBase());
+  LWasmLoadLaneSimd128* lir =
+      new (alloc()) LWasmLoadLaneSimd128(base, inputUse, temp(), LAllocation());
+  define(lir, ins);
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}
+
+void LIRGenerator::visitWasmStoreLaneSimd128(MWasmStoreLaneSimd128* ins) {
+#ifdef ENABLE_WASM_SIMD
+  // See comment above about the base pointer.
+
+  LUse base = useRegisterAtStart(ins->base());
+  LUse input = useRegisterAtStart(ins->value());
+  MOZ_ASSERT(!ins->hasMemoryBase());
+  LWasmStoreLaneSimd128* lir =
+      new (alloc()) LWasmStoreLaneSimd128(base, input, temp(), LAllocation());
+  add(lir, ins);
+#else
+  MOZ_CRASH("No SIMD");
+#endif
+}