From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 21:33:14 +0200
Subject: Adding upstream version 115.7.0esr.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 js/src/jit/CodeGenerator.cpp | 18631 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 18631 insertions(+)
 create mode 100644 js/src/jit/CodeGenerator.cpp

(limited to 'js/src/jit/CodeGenerator.cpp')

diff --git a/js/src/jit/CodeGenerator.cpp b/js/src/jit/CodeGenerator.cpp
new file mode 100644
index 0000000000..f4b7ea7e13
--- /dev/null
+++ b/js/src/jit/CodeGenerator.cpp
@@ -0,0 +1,18631 @@
+/* -*- 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/CodeGenerator.h"
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Casting.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/EnumeratedArray.h"
+#include "mozilla/EnumeratedRange.h"
+#include "mozilla/EnumSet.h"
+#include "mozilla/IntegerTypeTraits.h"
+#include "mozilla/Latin1.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/ScopeExit.h"
+
+#include <limits>
+#include <type_traits>
+#include <utility>
+
+#include "jslibmath.h"
+#include "jsmath.h"
+#include "jsnum.h"
+
+#include "builtin/MapObject.h"
+#include "builtin/RegExp.h"
+#include "builtin/String.h"
+#include "irregexp/RegExpTypes.h"
+#include "jit/ABIArgGenerator.h"
+#include "jit/CompileInfo.h"
+#include "jit/InlineScriptTree.h"
+#include "jit/Invalidation.h"
+#include "jit/IonIC.h"
+#include "jit/IonScript.h"
+#include "jit/JitcodeMap.h"
+#include "jit/JitFrames.h"
+#include "jit/JitRealm.h"
+#include "jit/JitRuntime.h"
+#include "jit/JitSpewer.h"
+#include "jit/JitZone.h"
+#include "jit/Linker.h"
+#include "jit/MIRGenerator.h"
+#include "jit/MoveEmitter.h"
+#include "jit/RangeAnalysis.h"
+#include "jit/RegExpStubConstants.h"
+#include "jit/SafepointIndex.h"
+#include "jit/SharedICHelpers.h"
+#include "jit/SharedICRegisters.h"
+#include "jit/VMFunctions.h"
+#include "jit/WarpSnapshot.h"
+#include "js/experimental/JitInfo.h"  // JSJit{Getter,Setter}CallArgs, JSJitMethodCallArgsTraits, JSJitInfo
+#include "js/friend/DOMProxy.h"  // JS::ExpandoAndGeneration
+#include "js/RegExpFlags.h"      // JS::RegExpFlag
+#include "js/ScalarType.h"       // js::Scalar::Type
+#include "proxy/DOMProxy.h"
+#include "util/CheckedArithmetic.h"
+#include "util/Unicode.h"
+#include "vm/ArrayBufferViewObject.h"
+#include "vm/AsyncFunction.h"
+#include "vm/AsyncIteration.h"
+#include "vm/BuiltinObjectKind.h"
+#include "vm/FunctionFlags.h"  // js::FunctionFlags
+#include "vm/Interpreter.h"
+#include "vm/JSAtom.h"
+#include "vm/MatchPairs.h"
+#include "vm/RegExpObject.h"
+#include "vm/RegExpStatics.h"
+#include "vm/StaticStrings.h"
+#include "vm/StringObject.h"
+#include "vm/StringType.h"
+#include "vm/TypedArrayObject.h"
+#include "wasm/WasmCodegenConstants.h"
+#include "wasm/WasmValType.h"
+#ifdef MOZ_VTUNE
+#  include "vtune/VTuneWrapper.h"
+#endif
+#include "wasm/WasmBinary.h"
+#include "wasm/WasmGC.h"
+#include "wasm/WasmGcObject.h"
+#include "wasm/WasmStubs.h"
+
+#include "builtin/Boolean-inl.h"
+#include "jit/MacroAssembler-inl.h"
+#include "jit/shared/CodeGenerator-shared-inl.h"
+#include "jit/TemplateObject-inl.h"
+#include "jit/VMFunctionList-inl.h"
+#include "vm/JSScript-inl.h"
+#include "wasm/WasmInstance-inl.h"
+
+using namespace js;
+using namespace js::jit;
+
+using JS::GenericNaN;
+using mozilla::AssertedCast;
+using mozilla::DebugOnly;
+using mozilla::FloatingPoint;
+using mozilla::Maybe;
+using mozilla::NegativeInfinity;
+using mozilla::PositiveInfinity;
+
+using JS::ExpandoAndGeneration;
+
+namespace js {
+namespace jit {
+
+#ifdef CHECK_OSIPOINT_REGISTERS
+template <class Op>
+static void HandleRegisterDump(Op op, MacroAssembler& masm,
+                               LiveRegisterSet liveRegs, Register activation,
+                               Register scratch) {
+  const size_t baseOffset = JitActivation::offsetOfRegs();
+
+  // Handle live GPRs.
+  for (GeneralRegisterIterator iter(liveRegs.gprs()); iter.more(); ++iter) {
+    Register reg = *iter;
+    Address dump(activation, baseOffset + RegisterDump::offsetOfRegister(reg));
+
+    if (reg == activation) {
+      // To use the original value of the activation register (that's
+      // now on top of the stack), we need the scratch register.
+      masm.push(scratch);
+      masm.loadPtr(Address(masm.getStackPointer(), sizeof(uintptr_t)), scratch);
+      op(scratch, dump);
+      masm.pop(scratch);
+    } else {
+      op(reg, dump);
+    }
+  }
+
+  // Handle live FPRs.
+  for (FloatRegisterIterator iter(liveRegs.fpus()); iter.more(); ++iter) {
+    FloatRegister reg = *iter;
+    Address dump(activation, baseOffset + RegisterDump::offsetOfRegister(reg));
+    op(reg, dump);
+  }
+}
+
+class StoreOp {
+  MacroAssembler& masm;
+
+ public:
+  explicit StoreOp(MacroAssembler& masm) : masm(masm) {}
+
+  void operator()(Register reg, Address dump) { masm.storePtr(reg, dump); }
+  void operator()(FloatRegister reg, Address dump) {
+    if (reg.isDouble()) {
+      masm.storeDouble(reg, dump);
+    } else if (reg.isSingle()) {
+      masm.storeFloat32(reg, dump);
+    } else if (reg.isSimd128()) {
+      MOZ_CRASH("Unexpected case for SIMD");
+    } else {
+      MOZ_CRASH("Unexpected register type.");
+    }
+  }
+};
+
+class VerifyOp {
+  MacroAssembler& masm;
+  Label* failure_;
+
+ public:
+  VerifyOp(MacroAssembler& masm, Label* failure)
+      : masm(masm), failure_(failure) {}
+
+  void operator()(Register reg, Address dump) {
+    masm.branchPtr(Assembler::NotEqual, dump, reg, failure_);
+  }
+  void operator()(FloatRegister reg, Address dump) {
+    if (reg.isDouble()) {
+      ScratchDoubleScope scratch(masm);
+      masm.loadDouble(dump, scratch);
+      masm.branchDouble(Assembler::DoubleNotEqual, scratch, reg, failure_);
+    } else if (reg.isSingle()) {
+      ScratchFloat32Scope scratch(masm);
+      masm.loadFloat32(dump, scratch);
+      masm.branchFloat(Assembler::DoubleNotEqual, scratch, reg, failure_);
+    } else if (reg.isSimd128()) {
+      MOZ_CRASH("Unexpected case for SIMD");
+    } else {
+      MOZ_CRASH("Unexpected register type.");
+    }
+  }
+};
+
+void CodeGenerator::verifyOsiPointRegs(LSafepoint* safepoint) {
+  // Ensure the live registers stored by callVM did not change between
+  // the call and this OsiPoint. Try-catch relies on this invariant.
+
+  // Load pointer to the JitActivation in a scratch register.
+  AllocatableGeneralRegisterSet allRegs(GeneralRegisterSet::All());
+  Register scratch = allRegs.takeAny();
+  masm.push(scratch);
+  masm.loadJitActivation(scratch);
+
+  // If we should not check registers (because the instruction did not call
+  // into the VM, or a GC happened), we're done.
+  Label failure, done;
+  Address checkRegs(scratch, JitActivation::offsetOfCheckRegs());
+  masm.branch32(Assembler::Equal, checkRegs, Imm32(0), &done);
+
+  // Having more than one VM function call made in one visit function at
+  // runtime is a sec-ciritcal error, because if we conservatively assume that
+  // one of the function call can re-enter Ion, then the invalidation process
+  // will potentially add a call at a random location, by patching the code
+  // before the return address.
+  masm.branch32(Assembler::NotEqual, checkRegs, Imm32(1), &failure);
+
+  // Set checkRegs to 0, so that we don't try to verify registers after we
+  // return from this script to the caller.
+  masm.store32(Imm32(0), checkRegs);
+
+  // Ignore clobbered registers. Some instructions (like LValueToInt32) modify
+  // temps after calling into the VM. This is fine because no other
+  // instructions (including this OsiPoint) will depend on them. Also
+  // backtracking can also use the same register for an input and an output.
+  // These are marked as clobbered and shouldn't get checked.
+  LiveRegisterSet liveRegs;
+  liveRegs.set() = RegisterSet::Intersect(
+      safepoint->liveRegs().set(),
+      RegisterSet::Not(safepoint->clobberedRegs().set()));
+
+  VerifyOp op(masm, &failure);
+  HandleRegisterDump<VerifyOp>(op, masm, liveRegs, scratch, allRegs.getAny());
+
+  masm.jump(&done);
+
+  // Do not profile the callWithABI that occurs below.  This is to avoid a
+  // rare corner case that occurs when profiling interacts with itself:
+  //
+  // When slow profiling assertions are turned on, FunctionBoundary ops
+  // (which update the profiler pseudo-stack) may emit a callVM, which
+  // forces them to have an osi point associated with them.  The
+  // FunctionBoundary for inline function entry is added to the caller's
+  // graph with a PC from the caller's code, but during codegen it modifies
+  // Gecko Profiler instrumentation to add the callee as the current top-most
+  // script. When codegen gets to the OSIPoint, and the callWithABI below is
+  // emitted, the codegen thinks that the current frame is the callee, but
+  // the PC it's using from the OSIPoint refers to the caller.  This causes
+  // the profiler instrumentation of the callWithABI below to ASSERT, since
+  // the script and pc are mismatched.  To avoid this, we simply omit
+  // instrumentation for these callWithABIs.
+
+  // Any live register captured by a safepoint (other than temp registers)
+  // must remain unchanged between the call and the OsiPoint instruction.
+  masm.bind(&failure);
+  masm.assumeUnreachable("Modified registers between VM call and OsiPoint");
+
+  masm.bind(&done);
+  masm.pop(scratch);
+}
+
+bool CodeGenerator::shouldVerifyOsiPointRegs(LSafepoint* safepoint) {
+  if (!checkOsiPointRegisters) {
+    return false;
+  }
+
+  if (safepoint->liveRegs().emptyGeneral() &&
+      safepoint->liveRegs().emptyFloat()) {
+    return false;  // No registers to check.
+  }
+
+  return true;
+}
+
+void CodeGenerator::resetOsiPointRegs(LSafepoint* safepoint) {
+  if (!shouldVerifyOsiPointRegs(safepoint)) {
+    return;
+  }
+
+  // Set checkRegs to 0. If we perform a VM call, the instruction
+  // will set it to 1.
+  AllocatableGeneralRegisterSet allRegs(GeneralRegisterSet::All());
+  Register scratch = allRegs.takeAny();
+  masm.push(scratch);
+  masm.loadJitActivation(scratch);
+  Address checkRegs(scratch, JitActivation::offsetOfCheckRegs());
+  masm.store32(Imm32(0), checkRegs);
+  masm.pop(scratch);
+}
+
+static void StoreAllLiveRegs(MacroAssembler& masm, LiveRegisterSet liveRegs) {
+  // Store a copy of all live registers before performing the call.
+  // When we reach the OsiPoint, we can use this to check nothing
+  // modified them in the meantime.
+
+  // Load pointer to the JitActivation in a scratch register.
+  AllocatableGeneralRegisterSet allRegs(GeneralRegisterSet::All());
+  Register scratch = allRegs.takeAny();
+  masm.push(scratch);
+  masm.loadJitActivation(scratch);
+
+  Address checkRegs(scratch, JitActivation::offsetOfCheckRegs());
+  masm.add32(Imm32(1), checkRegs);
+
+  StoreOp op(masm);
+  HandleRegisterDump<StoreOp>(op, masm, liveRegs, scratch, allRegs.getAny());
+
+  masm.pop(scratch);
+}
+#endif  // CHECK_OSIPOINT_REGISTERS
+
+// Before doing any call to Cpp, you should ensure that volatile
+// registers are evicted by the register allocator.
+void CodeGenerator::callVMInternal(VMFunctionId id, LInstruction* ins) {
+  TrampolinePtr code = gen->jitRuntime()->getVMWrapper(id);
+  const VMFunctionData& fun = GetVMFunction(id);
+
+  // Stack is:
+  //    ... frame ...
+  //    [args]
+#ifdef DEBUG
+  MOZ_ASSERT(pushedArgs_ == fun.explicitArgs);
+  pushedArgs_ = 0;
+#endif
+
+#ifdef CHECK_OSIPOINT_REGISTERS
+  if (shouldVerifyOsiPointRegs(ins->safepoint())) {
+    StoreAllLiveRegs(masm, ins->safepoint()->liveRegs());
+  }
+#endif
+
+#ifdef DEBUG
+  if (ins->mirRaw()) {
+    MOZ_ASSERT(ins->mirRaw()->isInstruction());
+    MInstruction* mir = ins->mirRaw()->toInstruction();
+    MOZ_ASSERT_IF(mir->needsResumePoint(), mir->resumePoint());
+
+    // If this MIR instruction has an overridden AliasSet, set the JitRuntime's
+    // disallowArbitraryCode_ flag so we can assert this VMFunction doesn't call
+    // RunScript. Whitelist MInterruptCheck and MCheckOverRecursed because
+    // interrupt callbacks can call JS (chrome JS or shell testing functions).
+    bool isWhitelisted = mir->isInterruptCheck() || mir->isCheckOverRecursed();
+    if (!mir->hasDefaultAliasSet() && !isWhitelisted) {
+      const void* addr = gen->jitRuntime()->addressOfDisallowArbitraryCode();
+      masm.move32(Imm32(1), ReturnReg);
+      masm.store32(ReturnReg, AbsoluteAddress(addr));
+    }
+  }
+#endif
+
+  // Push an exit frame descriptor.
+  masm.PushFrameDescriptor(FrameType::IonJS);
+
+  // Call the wrapper function.  The wrapper is in charge to unwind the stack
+  // when returning from the call.  Failures are handled with exceptions based
+  // on the return value of the C functions.  To guard the outcome of the
+  // returned value, use another LIR instruction.
+  ensureOsiSpace();
+  uint32_t callOffset = masm.callJit(code);
+  markSafepointAt(callOffset, ins);
+
+#ifdef DEBUG
+  // Reset the disallowArbitraryCode flag after the call.
+  {
+    const void* addr = gen->jitRuntime()->addressOfDisallowArbitraryCode();
+    masm.push(ReturnReg);
+    masm.move32(Imm32(0), ReturnReg);
+    masm.store32(ReturnReg, AbsoluteAddress(addr));
+    masm.pop(ReturnReg);
+  }
+#endif
+
+  // Pop rest of the exit frame and the arguments left on the stack.
+  int framePop =
+      sizeof(ExitFrameLayout) - ExitFrameLayout::bytesPoppedAfterCall();
+  masm.implicitPop(fun.explicitStackSlots() * sizeof(void*) + framePop);
+
+  // Stack is:
+  //    ... frame ...
+}
+
+template <typename Fn, Fn fn>
+void CodeGenerator::callVM(LInstruction* ins) {
+  VMFunctionId id = VMFunctionToId<Fn, fn>::id;
+  callVMInternal(id, ins);
+}
+
+// ArgSeq store arguments for OutOfLineCallVM.
+//
+// OutOfLineCallVM are created with "oolCallVM" function. The third argument of
+// this function is an instance of a class which provides a "generate" in charge
+// of pushing the argument, with "pushArg", for a VMFunction.
+//
+// Such list of arguments can be created by using the "ArgList" function which
+// creates one instance of "ArgSeq", where the type of the arguments are
+// inferred from the type of the arguments.
+//
+// The list of arguments must be written in the same order as if you were
+// calling the function in C++.
+//
+// Example:
+//   ArgList(ToRegister(lir->lhs()), ToRegister(lir->rhs()))
+
+template <typename... ArgTypes>
+class ArgSeq {
+  std::tuple<std::remove_reference_t<ArgTypes>...> args_;
+
+  template <std::size_t... ISeq>
+  inline void generate(CodeGenerator* codegen,
+                       std::index_sequence<ISeq...>) const {
+    // Arguments are pushed in reverse order, from last argument to first
+    // argument.
+    (codegen->pushArg(std::get<sizeof...(ISeq) - 1 - ISeq>(args_)), ...);
+  }
+
+ public:
+  explicit ArgSeq(ArgTypes&&... args)
+      : args_(std::forward<ArgTypes>(args)...) {}
+
+  inline void generate(CodeGenerator* codegen) const {
+    generate(codegen, std::index_sequence_for<ArgTypes...>{});
+  }
+
+#ifdef DEBUG
+  static constexpr size_t numArgs = sizeof...(ArgTypes);
+#endif
+};
+
+template <typename... ArgTypes>
+inline ArgSeq<ArgTypes...> ArgList(ArgTypes&&... args) {
+  return ArgSeq<ArgTypes...>(std::forward<ArgTypes>(args)...);
+}
+
+// Store wrappers, to generate the right move of data after the VM call.
+
+struct StoreNothing {
+  inline void generate(CodeGenerator* codegen) const {}
+  inline LiveRegisterSet clobbered() const {
+    return LiveRegisterSet();  // No register gets clobbered
+  }
+};
+
+class StoreRegisterTo {
+ private:
+  Register out_;
+
+ public:
+  explicit StoreRegisterTo(Register out) : out_(out) {}
+
+  inline void generate(CodeGenerator* codegen) const {
+    // It's okay to use storePointerResultTo here - the VMFunction wrapper
+    // ensures the upper bytes are zero for bool/int32 return values.
+    codegen->storePointerResultTo(out_);
+  }
+  inline LiveRegisterSet clobbered() const {
+    LiveRegisterSet set;
+    set.add(out_);
+    return set;
+  }
+};
+
+class StoreFloatRegisterTo {
+ private:
+  FloatRegister out_;
+
+ public:
+  explicit StoreFloatRegisterTo(FloatRegister out) : out_(out) {}
+
+  inline void generate(CodeGenerator* codegen) const {
+    codegen->storeFloatResultTo(out_);
+  }
+  inline LiveRegisterSet clobbered() const {
+    LiveRegisterSet set;
+    set.add(out_);
+    return set;
+  }
+};
+
+template <typename Output>
+class StoreValueTo_ {
+ private:
+  Output out_;
+
+ public:
+  explicit StoreValueTo_(const Output& out) : out_(out) {}
+
+  inline void generate(CodeGenerator* codegen) const {
+    codegen->storeResultValueTo(out_);
+  }
+  inline LiveRegisterSet clobbered() const {
+    LiveRegisterSet set;
+    set.add(out_);
+    return set;
+  }
+};
+
+template <typename Output>
+StoreValueTo_<Output> StoreValueTo(const Output& out) {
+  return StoreValueTo_<Output>(out);
+}
+
+template <typename Fn, Fn fn, class ArgSeq, class StoreOutputTo>
+class OutOfLineCallVM : public OutOfLineCodeBase<CodeGenerator> {
+ private:
+  LInstruction* lir_;
+  ArgSeq args_;
+  StoreOutputTo out_;
+
+ public:
+  OutOfLineCallVM(LInstruction* lir, const ArgSeq& args,
+                  const StoreOutputTo& out)
+      : lir_(lir), args_(args), out_(out) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineCallVM(this);
+  }
+
+  LInstruction* lir() const { return lir_; }
+  const ArgSeq& args() const { return args_; }
+  const StoreOutputTo& out() const { return out_; }
+};
+
+template <typename Fn, Fn fn, class ArgSeq, class StoreOutputTo>
+OutOfLineCode* CodeGenerator::oolCallVM(LInstruction* lir, const ArgSeq& args,
+                                        const StoreOutputTo& out) {
+  MOZ_ASSERT(lir->mirRaw());
+  MOZ_ASSERT(lir->mirRaw()->isInstruction());
+
+#ifdef DEBUG
+  VMFunctionId id = VMFunctionToId<Fn, fn>::id;
+  const VMFunctionData& fun = GetVMFunction(id);
+  MOZ_ASSERT(fun.explicitArgs == args.numArgs);
+  MOZ_ASSERT(fun.returnsData() !=
+             (std::is_same_v<StoreOutputTo, StoreNothing>));
+#endif
+
+  OutOfLineCode* ool = new (alloc())
+      OutOfLineCallVM<Fn, fn, ArgSeq, StoreOutputTo>(lir, args, out);
+  addOutOfLineCode(ool, lir->mirRaw()->toInstruction());
+  return ool;
+}
+
+template <typename Fn, Fn fn, class ArgSeq, class StoreOutputTo>
+void CodeGenerator::visitOutOfLineCallVM(
+    OutOfLineCallVM<Fn, fn, ArgSeq, StoreOutputTo>* ool) {
+  LInstruction* lir = ool->lir();
+
+  saveLive(lir);
+  ool->args().generate(this);
+  callVM<Fn, fn>(lir);
+  ool->out().generate(this);
+  restoreLiveIgnore(lir, ool->out().clobbered());
+  masm.jump(ool->rejoin());
+}
+
+class OutOfLineICFallback : public OutOfLineCodeBase<CodeGenerator> {
+ private:
+  LInstruction* lir_;
+  size_t cacheIndex_;
+  size_t cacheInfoIndex_;
+
+ public:
+  OutOfLineICFallback(LInstruction* lir, size_t cacheIndex,
+                      size_t cacheInfoIndex)
+      : lir_(lir), cacheIndex_(cacheIndex), cacheInfoIndex_(cacheInfoIndex) {}
+
+  void bind(MacroAssembler* masm) override {
+    // The binding of the initial jump is done in
+    // CodeGenerator::visitOutOfLineICFallback.
+  }
+
+  size_t cacheIndex() const { return cacheIndex_; }
+  size_t cacheInfoIndex() const { return cacheInfoIndex_; }
+  LInstruction* lir() const { return lir_; }
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineICFallback(this);
+  }
+};
+
+void CodeGeneratorShared::addIC(LInstruction* lir, size_t cacheIndex) {
+  if (cacheIndex == SIZE_MAX) {
+    masm.setOOM();
+    return;
+  }
+
+  DataPtr<IonIC> cache(this, cacheIndex);
+  MInstruction* mir = lir->mirRaw()->toInstruction();
+  cache->setScriptedLocation(mir->block()->info().script(),
+                             mir->resumePoint()->pc());
+
+  Register temp = cache->scratchRegisterForEntryJump();
+  icInfo_.back().icOffsetForJump = masm.movWithPatch(ImmWord(-1), temp);
+  masm.jump(Address(temp, 0));
+
+  MOZ_ASSERT(!icInfo_.empty());
+
+  OutOfLineICFallback* ool =
+      new (alloc()) OutOfLineICFallback(lir, cacheIndex, icInfo_.length() - 1);
+  addOutOfLineCode(ool, mir);
+
+  masm.bind(ool->rejoin());
+  cache->setRejoinOffset(CodeOffset(ool->rejoin()->offset()));
+}
+
+void CodeGenerator::visitOutOfLineICFallback(OutOfLineICFallback* ool) {
+  LInstruction* lir = ool->lir();
+  size_t cacheIndex = ool->cacheIndex();
+  size_t cacheInfoIndex = ool->cacheInfoIndex();
+
+  DataPtr<IonIC> ic(this, cacheIndex);
+
+  // Register the location of the OOL path in the IC.
+  ic->setFallbackOffset(CodeOffset(masm.currentOffset()));
+
+  switch (ic->kind()) {
+    case CacheKind::GetProp:
+    case CacheKind::GetElem: {
+      IonGetPropertyIC* getPropIC = ic->asGetPropertyIC();
+
+      saveLive(lir);
+
+      pushArg(getPropIC->id());
+      pushArg(getPropIC->value());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext*, HandleScript, IonGetPropertyIC*,
+                          HandleValue, HandleValue, MutableHandleValue);
+      callVM<Fn, IonGetPropertyIC::update>(lir);
+
+      StoreValueTo(getPropIC->output()).generate(this);
+      restoreLiveIgnore(lir, StoreValueTo(getPropIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::GetPropSuper:
+    case CacheKind::GetElemSuper: {
+      IonGetPropSuperIC* getPropSuperIC = ic->asGetPropSuperIC();
+
+      saveLive(lir);
+
+      pushArg(getPropSuperIC->id());
+      pushArg(getPropSuperIC->receiver());
+      pushArg(getPropSuperIC->object());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn =
+          bool (*)(JSContext*, HandleScript, IonGetPropSuperIC*, HandleObject,
+                   HandleValue, HandleValue, MutableHandleValue);
+      callVM<Fn, IonGetPropSuperIC::update>(lir);
+
+      StoreValueTo(getPropSuperIC->output()).generate(this);
+      restoreLiveIgnore(lir,
+                        StoreValueTo(getPropSuperIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::SetProp:
+    case CacheKind::SetElem: {
+      IonSetPropertyIC* setPropIC = ic->asSetPropertyIC();
+
+      saveLive(lir);
+
+      pushArg(setPropIC->rhs());
+      pushArg(setPropIC->id());
+      pushArg(setPropIC->object());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext*, HandleScript, IonSetPropertyIC*,
+                          HandleObject, HandleValue, HandleValue);
+      callVM<Fn, IonSetPropertyIC::update>(lir);
+
+      restoreLive(lir);
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::GetName: {
+      IonGetNameIC* getNameIC = ic->asGetNameIC();
+
+      saveLive(lir);
+
+      pushArg(getNameIC->environment());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext*, HandleScript, IonGetNameIC*, HandleObject,
+                          MutableHandleValue);
+      callVM<Fn, IonGetNameIC::update>(lir);
+
+      StoreValueTo(getNameIC->output()).generate(this);
+      restoreLiveIgnore(lir, StoreValueTo(getNameIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::BindName: {
+      IonBindNameIC* bindNameIC = ic->asBindNameIC();
+
+      saveLive(lir);
+
+      pushArg(bindNameIC->environment());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn =
+          JSObject* (*)(JSContext*, HandleScript, IonBindNameIC*, HandleObject);
+      callVM<Fn, IonBindNameIC::update>(lir);
+
+      StoreRegisterTo(bindNameIC->output()).generate(this);
+      restoreLiveIgnore(lir, StoreRegisterTo(bindNameIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::GetIterator: {
+      IonGetIteratorIC* getIteratorIC = ic->asGetIteratorIC();
+
+      saveLive(lir);
+
+      pushArg(getIteratorIC->value());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = JSObject* (*)(JSContext*, HandleScript, IonGetIteratorIC*,
+                               HandleValue);
+      callVM<Fn, IonGetIteratorIC::update>(lir);
+
+      StoreRegisterTo(getIteratorIC->output()).generate(this);
+      restoreLiveIgnore(lir,
+                        StoreRegisterTo(getIteratorIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::OptimizeSpreadCall: {
+      auto* optimizeSpreadCallIC = ic->asOptimizeSpreadCallIC();
+
+      saveLive(lir);
+
+      pushArg(optimizeSpreadCallIC->value());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext*, HandleScript, IonOptimizeSpreadCallIC*,
+                          HandleValue, MutableHandleValue);
+      callVM<Fn, IonOptimizeSpreadCallIC::update>(lir);
+
+      StoreValueTo(optimizeSpreadCallIC->output()).generate(this);
+      restoreLiveIgnore(
+          lir, StoreValueTo(optimizeSpreadCallIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::In: {
+      IonInIC* inIC = ic->asInIC();
+
+      saveLive(lir);
+
+      pushArg(inIC->object());
+      pushArg(inIC->key());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext*, HandleScript, IonInIC*, HandleValue,
+                          HandleObject, bool*);
+      callVM<Fn, IonInIC::update>(lir);
+
+      StoreRegisterTo(inIC->output()).generate(this);
+      restoreLiveIgnore(lir, StoreRegisterTo(inIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::HasOwn: {
+      IonHasOwnIC* hasOwnIC = ic->asHasOwnIC();
+
+      saveLive(lir);
+
+      pushArg(hasOwnIC->id());
+      pushArg(hasOwnIC->value());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext*, HandleScript, IonHasOwnIC*, HandleValue,
+                          HandleValue, int32_t*);
+      callVM<Fn, IonHasOwnIC::update>(lir);
+
+      StoreRegisterTo(hasOwnIC->output()).generate(this);
+      restoreLiveIgnore(lir, StoreRegisterTo(hasOwnIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::CheckPrivateField: {
+      IonCheckPrivateFieldIC* checkPrivateFieldIC = ic->asCheckPrivateFieldIC();
+
+      saveLive(lir);
+
+      pushArg(checkPrivateFieldIC->id());
+      pushArg(checkPrivateFieldIC->value());
+
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext*, HandleScript, IonCheckPrivateFieldIC*,
+                          HandleValue, HandleValue, bool*);
+      callVM<Fn, IonCheckPrivateFieldIC::update>(lir);
+
+      StoreRegisterTo(checkPrivateFieldIC->output()).generate(this);
+      restoreLiveIgnore(
+          lir, StoreRegisterTo(checkPrivateFieldIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::InstanceOf: {
+      IonInstanceOfIC* hasInstanceOfIC = ic->asInstanceOfIC();
+
+      saveLive(lir);
+
+      pushArg(hasInstanceOfIC->rhs());
+      pushArg(hasInstanceOfIC->lhs());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext*, HandleScript, IonInstanceOfIC*,
+                          HandleValue lhs, HandleObject rhs, bool* res);
+      callVM<Fn, IonInstanceOfIC::update>(lir);
+
+      StoreRegisterTo(hasInstanceOfIC->output()).generate(this);
+      restoreLiveIgnore(lir,
+                        StoreRegisterTo(hasInstanceOfIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::UnaryArith: {
+      IonUnaryArithIC* unaryArithIC = ic->asUnaryArithIC();
+
+      saveLive(lir);
+
+      pushArg(unaryArithIC->input());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext* cx, HandleScript outerScript,
+                          IonUnaryArithIC* stub, HandleValue val,
+                          MutableHandleValue res);
+      callVM<Fn, IonUnaryArithIC::update>(lir);
+
+      StoreValueTo(unaryArithIC->output()).generate(this);
+      restoreLiveIgnore(lir, StoreValueTo(unaryArithIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::ToPropertyKey: {
+      IonToPropertyKeyIC* toPropertyKeyIC = ic->asToPropertyKeyIC();
+
+      saveLive(lir);
+
+      pushArg(toPropertyKeyIC->input());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext* cx, HandleScript outerScript,
+                          IonToPropertyKeyIC* ic, HandleValue val,
+                          MutableHandleValue res);
+      callVM<Fn, IonToPropertyKeyIC::update>(lir);
+
+      StoreValueTo(toPropertyKeyIC->output()).generate(this);
+      restoreLiveIgnore(lir,
+                        StoreValueTo(toPropertyKeyIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::BinaryArith: {
+      IonBinaryArithIC* binaryArithIC = ic->asBinaryArithIC();
+
+      saveLive(lir);
+
+      pushArg(binaryArithIC->rhs());
+      pushArg(binaryArithIC->lhs());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn = bool (*)(JSContext* cx, HandleScript outerScript,
+                          IonBinaryArithIC* stub, HandleValue lhs,
+                          HandleValue rhs, MutableHandleValue res);
+      callVM<Fn, IonBinaryArithIC::update>(lir);
+
+      StoreValueTo(binaryArithIC->output()).generate(this);
+      restoreLiveIgnore(lir, StoreValueTo(binaryArithIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::Compare: {
+      IonCompareIC* compareIC = ic->asCompareIC();
+
+      saveLive(lir);
+
+      pushArg(compareIC->rhs());
+      pushArg(compareIC->lhs());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn =
+          bool (*)(JSContext* cx, HandleScript outerScript, IonCompareIC* stub,
+                   HandleValue lhs, HandleValue rhs, bool* res);
+      callVM<Fn, IonCompareIC::update>(lir);
+
+      StoreRegisterTo(compareIC->output()).generate(this);
+      restoreLiveIgnore(lir, StoreRegisterTo(compareIC->output()).clobbered());
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::CloseIter: {
+      IonCloseIterIC* closeIterIC = ic->asCloseIterIC();
+
+      saveLive(lir);
+
+      pushArg(closeIterIC->iter());
+      icInfo_[cacheInfoIndex].icOffsetForPush = pushArgWithPatch(ImmWord(-1));
+      pushArg(ImmGCPtr(gen->outerInfo().script()));
+
+      using Fn =
+          bool (*)(JSContext*, HandleScript, IonCloseIterIC*, HandleObject);
+      callVM<Fn, IonCloseIterIC::update>(lir);
+
+      restoreLive(lir);
+
+      masm.jump(ool->rejoin());
+      return;
+    }
+    case CacheKind::Call:
+    case CacheKind::TypeOf:
+    case CacheKind::ToBool:
+    case CacheKind::GetIntrinsic:
+    case CacheKind::NewArray:
+    case CacheKind::NewObject:
+      MOZ_CRASH("Unsupported IC");
+  }
+  MOZ_CRASH();
+}
+
+StringObject* MNewStringObject::templateObj() const {
+  return &templateObj_->as<StringObject>();
+}
+
+CodeGenerator::CodeGenerator(MIRGenerator* gen, LIRGraph* graph,
+                             MacroAssembler* masm)
+    : CodeGeneratorSpecific(gen, graph, masm),
+      ionScriptLabels_(gen->alloc()),
+      ionNurseryObjectLabels_(gen->alloc()),
+      scriptCounts_(nullptr),
+      realmStubsToReadBarrier_(0) {}
+
+CodeGenerator::~CodeGenerator() { js_delete(scriptCounts_); }
+
+void CodeGenerator::visitValueToInt32(LValueToInt32* lir) {
+  ValueOperand operand = ToValue(lir, LValueToInt32::Input);
+  Register output = ToRegister(lir->output());
+  FloatRegister temp = ToFloatRegister(lir->tempFloat());
+
+  Label fails;
+  if (lir->mode() == LValueToInt32::TRUNCATE) {
+    OutOfLineCode* oolDouble = oolTruncateDouble(temp, output, lir->mir());
+
+    // We can only handle strings in truncation contexts, like bitwise
+    // operations.
+    Register stringReg = ToRegister(lir->temp());
+    using Fn = bool (*)(JSContext*, JSString*, double*);
+    auto* oolString = oolCallVM<Fn, StringToNumber>(lir, ArgList(stringReg),
+                                                    StoreFloatRegisterTo(temp));
+    Label* stringEntry = oolString->entry();
+    Label* stringRejoin = oolString->rejoin();
+
+    masm.truncateValueToInt32(operand, stringEntry, stringRejoin,
+                              oolDouble->entry(), stringReg, temp, output,
+                              &fails);
+    masm.bind(oolDouble->rejoin());
+  } else {
+    MOZ_ASSERT(lir->mode() == LValueToInt32::NORMAL);
+    masm.convertValueToInt32(operand, temp, output, &fails,
+                             lir->mirNormal()->needsNegativeZeroCheck(),
+                             lir->mirNormal()->conversion());
+  }
+
+  bailoutFrom(&fails, lir->snapshot());
+}
+
+void CodeGenerator::visitValueToDouble(LValueToDouble* lir) {
+  ValueOperand operand = ToValue(lir, LValueToDouble::InputIndex);
+  FloatRegister output = ToFloatRegister(lir->output());
+
+  // Set if we can handle other primitives beside strings, as long as they're
+  // guaranteed to never throw. This rules out symbols and BigInts, but allows
+  // booleans, undefined, and null.
+  bool hasNonStringPrimitives =
+      lir->mir()->conversion() == MToFPInstruction::NonStringPrimitives;
+
+  Label isDouble, isInt32, isBool, isNull, isUndefined, done;
+
+  {
+    ScratchTagScope tag(masm, operand);
+    masm.splitTagForTest(operand, tag);
+
+    masm.branchTestDouble(Assembler::Equal, tag, &isDouble);
+    masm.branchTestInt32(Assembler::Equal, tag, &isInt32);
+
+    if (hasNonStringPrimitives) {
+      masm.branchTestBoolean(Assembler::Equal, tag, &isBool);
+      masm.branchTestUndefined(Assembler::Equal, tag, &isUndefined);
+      masm.branchTestNull(Assembler::Equal, tag, &isNull);
+    }
+  }
+
+  bailout(lir->snapshot());
+
+  if (hasNonStringPrimitives) {
+    masm.bind(&isNull);
+    masm.loadConstantDouble(0.0, output);
+    masm.jump(&done);
+  }
+
+  if (hasNonStringPrimitives) {
+    masm.bind(&isUndefined);
+    masm.loadConstantDouble(GenericNaN(), output);
+    masm.jump(&done);
+  }
+
+  if (hasNonStringPrimitives) {
+    masm.bind(&isBool);
+    masm.boolValueToDouble(operand, output);
+    masm.jump(&done);
+  }
+
+  masm.bind(&isInt32);
+  masm.int32ValueToDouble(operand, output);
+  masm.jump(&done);
+
+  masm.bind(&isDouble);
+  masm.unboxDouble(operand, output);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitValueToFloat32(LValueToFloat32* lir) {
+  ValueOperand operand = ToValue(lir, LValueToFloat32::InputIndex);
+  FloatRegister output = ToFloatRegister(lir->output());
+
+  // Set if we can handle other primitives beside strings, as long as they're
+  // guaranteed to never throw. This rules out symbols and BigInts, but allows
+  // booleans, undefined, and null.
+  bool hasNonStringPrimitives =
+      lir->mir()->conversion() == MToFPInstruction::NonStringPrimitives;
+
+  Label isDouble, isInt32, isBool, isNull, isUndefined, done;
+
+  {
+    ScratchTagScope tag(masm, operand);
+    masm.splitTagForTest(operand, tag);
+
+    masm.branchTestDouble(Assembler::Equal, tag, &isDouble);
+    masm.branchTestInt32(Assembler::Equal, tag, &isInt32);
+
+    if (hasNonStringPrimitives) {
+      masm.branchTestBoolean(Assembler::Equal, tag, &isBool);
+      masm.branchTestUndefined(Assembler::Equal, tag, &isUndefined);
+      masm.branchTestNull(Assembler::Equal, tag, &isNull);
+    }
+  }
+
+  bailout(lir->snapshot());
+
+  if (hasNonStringPrimitives) {
+    masm.bind(&isNull);
+    masm.loadConstantFloat32(0.0f, output);
+    masm.jump(&done);
+  }
+
+  if (hasNonStringPrimitives) {
+    masm.bind(&isUndefined);
+    masm.loadConstantFloat32(float(GenericNaN()), output);
+    masm.jump(&done);
+  }
+
+  if (hasNonStringPrimitives) {
+    masm.bind(&isBool);
+    masm.boolValueToFloat32(operand, output);
+    masm.jump(&done);
+  }
+
+  masm.bind(&isInt32);
+  masm.int32ValueToFloat32(operand, output);
+  masm.jump(&done);
+
+  masm.bind(&isDouble);
+  // ARM and MIPS may not have a double register available if we've
+  // allocated output as a float32.
+#if defined(JS_CODEGEN_ARM) || defined(JS_CODEGEN_MIPS32)
+  ScratchDoubleScope fpscratch(masm);
+  masm.unboxDouble(operand, fpscratch);
+  masm.convertDoubleToFloat32(fpscratch, output);
+#else
+  masm.unboxDouble(operand, output);
+  masm.convertDoubleToFloat32(output, output);
+#endif
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitValueToBigInt(LValueToBigInt* lir) {
+  ValueOperand operand = ToValue(lir, LValueToBigInt::InputIndex);
+  Register output = ToRegister(lir->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleValue);
+  auto* ool =
+      oolCallVM<Fn, ToBigInt>(lir, ArgList(operand), StoreRegisterTo(output));
+
+  Register tag = masm.extractTag(operand, output);
+
+  Label notBigInt, done;
+  masm.branchTestBigInt(Assembler::NotEqual, tag, &notBigInt);
+  masm.unboxBigInt(operand, output);
+  masm.jump(&done);
+  masm.bind(&notBigInt);
+
+  masm.branchTestBoolean(Assembler::Equal, tag, ool->entry());
+  masm.branchTestString(Assembler::Equal, tag, ool->entry());
+
+  // ToBigInt(object) can have side-effects; all other types throw a TypeError.
+  bailout(lir->snapshot());
+
+  masm.bind(ool->rejoin());
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitInt32ToDouble(LInt32ToDouble* lir) {
+  masm.convertInt32ToDouble(ToRegister(lir->input()),
+                            ToFloatRegister(lir->output()));
+}
+
+void CodeGenerator::visitFloat32ToDouble(LFloat32ToDouble* lir) {
+  masm.convertFloat32ToDouble(ToFloatRegister(lir->input()),
+                              ToFloatRegister(lir->output()));
+}
+
+void CodeGenerator::visitDoubleToFloat32(LDoubleToFloat32* lir) {
+  masm.convertDoubleToFloat32(ToFloatRegister(lir->input()),
+                              ToFloatRegister(lir->output()));
+}
+
+void CodeGenerator::visitInt32ToFloat32(LInt32ToFloat32* lir) {
+  masm.convertInt32ToFloat32(ToRegister(lir->input()),
+                             ToFloatRegister(lir->output()));
+}
+
+void CodeGenerator::visitDoubleToInt32(LDoubleToInt32* lir) {
+  Label fail;
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+  masm.convertDoubleToInt32(input, output, &fail,
+                            lir->mir()->needsNegativeZeroCheck());
+  bailoutFrom(&fail, lir->snapshot());
+}
+
+void CodeGenerator::visitFloat32ToInt32(LFloat32ToInt32* lir) {
+  Label fail;
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+  masm.convertFloat32ToInt32(input, output, &fail,
+                             lir->mir()->needsNegativeZeroCheck());
+  bailoutFrom(&fail, lir->snapshot());
+}
+
+void CodeGenerator::visitInt32ToIntPtr(LInt32ToIntPtr* lir) {
+#ifdef JS_64BIT
+  // This LIR instruction is only used if the input can be negative.
+  MOZ_ASSERT(lir->mir()->canBeNegative());
+
+  Register output = ToRegister(lir->output());
+  const LAllocation* input = lir->input();
+  if (input->isRegister()) {
+    masm.move32SignExtendToPtr(ToRegister(input), output);
+  } else {
+    masm.load32SignExtendToPtr(ToAddress(input), output);
+  }
+#else
+  MOZ_CRASH("Not used on 32-bit platforms");
+#endif
+}
+
+void CodeGenerator::visitNonNegativeIntPtrToInt32(
+    LNonNegativeIntPtrToInt32* lir) {
+#ifdef JS_64BIT
+  Register output = ToRegister(lir->output());
+  MOZ_ASSERT(ToRegister(lir->input()) == output);
+
+  Label bail;
+  masm.guardNonNegativeIntPtrToInt32(output, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+#else
+  MOZ_CRASH("Not used on 32-bit platforms");
+#endif
+}
+
+void CodeGenerator::visitIntPtrToDouble(LIntPtrToDouble* lir) {
+  Register input = ToRegister(lir->input());
+  FloatRegister output = ToFloatRegister(lir->output());
+  masm.convertIntPtrToDouble(input, output);
+}
+
+void CodeGenerator::visitAdjustDataViewLength(LAdjustDataViewLength* lir) {
+  Register output = ToRegister(lir->output());
+  MOZ_ASSERT(ToRegister(lir->input()) == output);
+
+  uint32_t byteSize = lir->mir()->byteSize();
+
+#ifdef DEBUG
+  Label ok;
+  masm.branchTestPtr(Assembler::NotSigned, output, output, &ok);
+  masm.assumeUnreachable("Unexpected negative value in LAdjustDataViewLength");
+  masm.bind(&ok);
+#endif
+
+  Label bail;
+  masm.branchSubPtr(Assembler::Signed, Imm32(byteSize - 1), output, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::emitOOLTestObject(Register objreg,
+                                      Label* ifEmulatesUndefined,
+                                      Label* ifDoesntEmulateUndefined,
+                                      Register scratch) {
+  saveVolatile(scratch);
+  using Fn = bool (*)(JSObject* obj);
+  masm.setupAlignedABICall();
+  masm.passABIArg(objreg);
+  masm.callWithABI<Fn, js::EmulatesUndefined>();
+  masm.storeCallPointerResult(scratch);
+  restoreVolatile(scratch);
+
+  masm.branchIfTrueBool(scratch, ifEmulatesUndefined);
+  masm.jump(ifDoesntEmulateUndefined);
+}
+
+// Base out-of-line code generator for all tests of the truthiness of an
+// object, where the object might not be truthy.  (Recall that per spec all
+// objects are truthy, but we implement the JSCLASS_EMULATES_UNDEFINED class
+// flag to permit objects to look like |undefined| in certain contexts,
+// including in object truthiness testing.)  We check truthiness inline except
+// when we're testing it on a proxy, in which case out-of-line code will call
+// EmulatesUndefined for a conclusive answer.
+class OutOfLineTestObject : public OutOfLineCodeBase<CodeGenerator> {
+  Register objreg_;
+  Register scratch_;
+
+  Label* ifEmulatesUndefined_;
+  Label* ifDoesntEmulateUndefined_;
+
+#ifdef DEBUG
+  bool initialized() { return ifEmulatesUndefined_ != nullptr; }
+#endif
+
+ public:
+  OutOfLineTestObject()
+      : ifEmulatesUndefined_(nullptr), ifDoesntEmulateUndefined_(nullptr) {}
+
+  void accept(CodeGenerator* codegen) final {
+    MOZ_ASSERT(initialized());
+    codegen->emitOOLTestObject(objreg_, ifEmulatesUndefined_,
+                               ifDoesntEmulateUndefined_, scratch_);
+  }
+
+  // Specify the register where the object to be tested is found, labels to
+  // jump to if the object is truthy or falsy, and a scratch register for
+  // use in the out-of-line path.
+  void setInputAndTargets(Register objreg, Label* ifEmulatesUndefined,
+                          Label* ifDoesntEmulateUndefined, Register scratch) {
+    MOZ_ASSERT(!initialized());
+    MOZ_ASSERT(ifEmulatesUndefined);
+    objreg_ = objreg;
+    scratch_ = scratch;
+    ifEmulatesUndefined_ = ifEmulatesUndefined;
+    ifDoesntEmulateUndefined_ = ifDoesntEmulateUndefined;
+  }
+};
+
+// A subclass of OutOfLineTestObject containing two extra labels, for use when
+// the ifTruthy/ifFalsy labels are needed in inline code as well as out-of-line
+// code.  The user should bind these labels in inline code, and specify them as
+// targets via setInputAndTargets, as appropriate.
+class OutOfLineTestObjectWithLabels : public OutOfLineTestObject {
+  Label label1_;
+  Label label2_;
+
+ public:
+  OutOfLineTestObjectWithLabels() = default;
+
+  Label* label1() { return &label1_; }
+  Label* label2() { return &label2_; }
+};
+
+void CodeGenerator::testObjectEmulatesUndefinedKernel(
+    Register objreg, Label* ifEmulatesUndefined,
+    Label* ifDoesntEmulateUndefined, Register scratch,
+    OutOfLineTestObject* ool) {
+  ool->setInputAndTargets(objreg, ifEmulatesUndefined, ifDoesntEmulateUndefined,
+                          scratch);
+
+  // Perform a fast-path check of the object's class flags if the object's
+  // not a proxy.  Let out-of-line code handle the slow cases that require
+  // saving registers, making a function call, and restoring registers.
+  masm.branchIfObjectEmulatesUndefined(objreg, scratch, ool->entry(),
+                                       ifEmulatesUndefined);
+}
+
+void CodeGenerator::branchTestObjectEmulatesUndefined(
+    Register objreg, Label* ifEmulatesUndefined,
+    Label* ifDoesntEmulateUndefined, Register scratch,
+    OutOfLineTestObject* ool) {
+  MOZ_ASSERT(!ifDoesntEmulateUndefined->bound(),
+             "ifDoesntEmulateUndefined will be bound to the fallthrough path");
+
+  testObjectEmulatesUndefinedKernel(objreg, ifEmulatesUndefined,
+                                    ifDoesntEmulateUndefined, scratch, ool);
+  masm.bind(ifDoesntEmulateUndefined);
+}
+
+void CodeGenerator::testObjectEmulatesUndefined(Register objreg,
+                                                Label* ifEmulatesUndefined,
+                                                Label* ifDoesntEmulateUndefined,
+                                                Register scratch,
+                                                OutOfLineTestObject* ool) {
+  testObjectEmulatesUndefinedKernel(objreg, ifEmulatesUndefined,
+                                    ifDoesntEmulateUndefined, scratch, ool);
+  masm.jump(ifDoesntEmulateUndefined);
+}
+
+void CodeGenerator::testValueTruthyForType(
+    JSValueType type, ScratchTagScope& tag, const ValueOperand& value,
+    Register tempToUnbox, Register temp, FloatRegister floatTemp,
+    Label* ifTruthy, Label* ifFalsy, OutOfLineTestObject* ool,
+    bool skipTypeTest) {
+#ifdef DEBUG
+  if (skipTypeTest) {
+    Label expected;
+    masm.branchTestType(Assembler::Equal, tag, type, &expected);
+    masm.assumeUnreachable("Unexpected Value type in testValueTruthyForType");
+    masm.bind(&expected);
+  }
+#endif
+
+  // Handle irregular types first.
+  switch (type) {
+    case JSVAL_TYPE_UNDEFINED:
+    case JSVAL_TYPE_NULL:
+      // Undefined and null are falsy.
+      if (!skipTypeTest) {
+        masm.branchTestType(Assembler::Equal, tag, type, ifFalsy);
+      } else {
+        masm.jump(ifFalsy);
+      }
+      return;
+    case JSVAL_TYPE_SYMBOL:
+      // Symbols are truthy.
+      if (!skipTypeTest) {
+        masm.branchTestSymbol(Assembler::Equal, tag, ifTruthy);
+      } else {
+        masm.jump(ifTruthy);
+      }
+      return;
+    case JSVAL_TYPE_OBJECT: {
+      Label notObject;
+      if (!skipTypeTest) {
+        masm.branchTestObject(Assembler::NotEqual, tag, &notObject);
+      }
+      ScratchTagScopeRelease _(&tag);
+      Register objreg = masm.extractObject(value, tempToUnbox);
+      testObjectEmulatesUndefined(objreg, ifFalsy, ifTruthy, temp, ool);
+      masm.bind(&notObject);
+      return;
+    }
+    default:
+      break;
+  }
+
+  // Check the type of the value (unless this is the last possible type).
+  Label differentType;
+  if (!skipTypeTest) {
+    masm.branchTestType(Assembler::NotEqual, tag, type, &differentType);
+  }
+
+  // Branch if the value is falsy.
+  ScratchTagScopeRelease _(&tag);
+  switch (type) {
+    case JSVAL_TYPE_BOOLEAN: {
+      masm.branchTestBooleanTruthy(false, value, ifFalsy);
+      break;
+    }
+    case JSVAL_TYPE_INT32: {
+      masm.branchTestInt32Truthy(false, value, ifFalsy);
+      break;
+    }
+    case JSVAL_TYPE_STRING: {
+      masm.branchTestStringTruthy(false, value, ifFalsy);
+      break;
+    }
+    case JSVAL_TYPE_BIGINT: {
+      masm.branchTestBigIntTruthy(false, value, ifFalsy);
+      break;
+    }
+    case JSVAL_TYPE_DOUBLE: {
+      masm.unboxDouble(value, floatTemp);
+      masm.branchTestDoubleTruthy(false, floatTemp, ifFalsy);
+      break;
+    }
+    default:
+      MOZ_CRASH("Unexpected value type");
+  }
+
+  // If we reach this point, the value is truthy.  We fall through for
+  // truthy on the last test; otherwise, branch.
+  if (!skipTypeTest) {
+    masm.jump(ifTruthy);
+  }
+
+  masm.bind(&differentType);
+}
+
+void CodeGenerator::testValueTruthy(const ValueOperand& value,
+                                    Register tempToUnbox, Register temp,
+                                    FloatRegister floatTemp,
+                                    const TypeDataList& observedTypes,
+                                    Label* ifTruthy, Label* ifFalsy,
+                                    OutOfLineTestObject* ool) {
+  ScratchTagScope tag(masm, value);
+  masm.splitTagForTest(value, tag);
+
+  const std::initializer_list<JSValueType> defaultOrder = {
+      JSVAL_TYPE_UNDEFINED, JSVAL_TYPE_NULL,   JSVAL_TYPE_BOOLEAN,
+      JSVAL_TYPE_INT32,     JSVAL_TYPE_OBJECT, JSVAL_TYPE_STRING,
+      JSVAL_TYPE_DOUBLE,    JSVAL_TYPE_SYMBOL, JSVAL_TYPE_BIGINT};
+
+  mozilla::EnumSet<JSValueType, uint32_t> remaining(defaultOrder);
+
+  // Generate tests for previously observed types first.
+  // The TypeDataList is sorted by descending frequency.
+  for (auto& observed : observedTypes) {
+    JSValueType type = observed.type();
+    remaining -= type;
+
+    testValueTruthyForType(type, tag, value, tempToUnbox, temp, floatTemp,
+                           ifTruthy, ifFalsy, ool, /*skipTypeTest*/ false);
+  }
+
+  // Generate tests for remaining types.
+  for (auto type : defaultOrder) {
+    if (!remaining.contains(type)) {
+      continue;
+    }
+    remaining -= type;
+
+    // We don't need a type test for the last possible type.
+    bool skipTypeTest = remaining.isEmpty();
+    testValueTruthyForType(type, tag, value, tempToUnbox, temp, floatTemp,
+                           ifTruthy, ifFalsy, ool, skipTypeTest);
+  }
+  MOZ_ASSERT(remaining.isEmpty());
+
+  // We fall through if the final test is truthy.
+}
+
+void CodeGenerator::visitTestBIAndBranch(LTestBIAndBranch* lir) {
+  Label* ifTrueLabel = getJumpLabelForBranch(lir->ifTrue());
+  Label* ifFalseLabel = getJumpLabelForBranch(lir->ifFalse());
+  Register input = ToRegister(lir->input());
+
+  if (isNextBlock(lir->ifFalse()->lir())) {
+    masm.branchIfBigIntIsNonZero(input, ifTrueLabel);
+  } else if (isNextBlock(lir->ifTrue()->lir())) {
+    masm.branchIfBigIntIsZero(input, ifFalseLabel);
+  } else {
+    masm.branchIfBigIntIsZero(input, ifFalseLabel);
+    jumpToBlock(lir->ifTrue());
+  }
+}
+
+void CodeGenerator::visitTestOAndBranch(LTestOAndBranch* lir) {
+  Label* truthy = getJumpLabelForBranch(lir->ifTruthy());
+  Label* falsy = getJumpLabelForBranch(lir->ifFalsy());
+  Register input = ToRegister(lir->input());
+
+  auto* ool = new (alloc()) OutOfLineTestObject();
+  addOutOfLineCode(ool, lir->mir());
+
+  testObjectEmulatesUndefined(input, falsy, truthy, ToRegister(lir->temp()),
+                              ool);
+}
+
+void CodeGenerator::visitTestVAndBranch(LTestVAndBranch* lir) {
+  auto* ool = new (alloc()) OutOfLineTestObject();
+  addOutOfLineCode(ool, lir->mir());
+
+  Label* truthy = getJumpLabelForBranch(lir->ifTruthy());
+  Label* falsy = getJumpLabelForBranch(lir->ifFalsy());
+
+  ValueOperand input = ToValue(lir, LTestVAndBranch::Input);
+  Register tempToUnbox = ToTempUnboxRegister(lir->temp1());
+  Register temp = ToRegister(lir->temp2());
+  FloatRegister floatTemp = ToFloatRegister(lir->tempFloat());
+  const TypeDataList& observedTypes = lir->mir()->observedTypes();
+
+  testValueTruthy(input, tempToUnbox, temp, floatTemp, observedTypes, truthy,
+                  falsy, ool);
+  masm.jump(truthy);
+}
+
+void CodeGenerator::visitBooleanToString(LBooleanToString* lir) {
+  Register input = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+  const JSAtomState& names = gen->runtime->names();
+  Label true_, done;
+
+  masm.branchTest32(Assembler::NonZero, input, input, &true_);
+  masm.movePtr(ImmGCPtr(names.false_), output);
+  masm.jump(&done);
+
+  masm.bind(&true_);
+  masm.movePtr(ImmGCPtr(names.true_), output);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::emitIntToString(Register input, Register output,
+                                    Label* ool) {
+  masm.boundsCheck32PowerOfTwo(input, StaticStrings::INT_STATIC_LIMIT, ool);
+
+  // Fast path for small integers.
+  masm.movePtr(ImmPtr(&gen->runtime->staticStrings().intStaticTable), output);
+  masm.loadPtr(BaseIndex(output, input, ScalePointer), output);
+}
+
+void CodeGenerator::visitIntToString(LIntToString* lir) {
+  Register input = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  using Fn = JSLinearString* (*)(JSContext*, int);
+  OutOfLineCode* ool = oolCallVM<Fn, Int32ToString<CanGC>>(
+      lir, ArgList(input), StoreRegisterTo(output));
+
+  emitIntToString(input, output, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitDoubleToString(LDoubleToString* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register temp = ToRegister(lir->temp0());
+  Register output = ToRegister(lir->output());
+
+  using Fn = JSString* (*)(JSContext*, double);
+  OutOfLineCode* ool = oolCallVM<Fn, NumberToString<CanGC>>(
+      lir, ArgList(input), StoreRegisterTo(output));
+
+  // Try double to integer conversion and run integer to string code.
+  masm.convertDoubleToInt32(input, temp, ool->entry(), false);
+  emitIntToString(temp, output, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitValueToString(LValueToString* lir) {
+  ValueOperand input = ToValue(lir, LValueToString::InputIndex);
+  Register output = ToRegister(lir->output());
+
+  using Fn = JSString* (*)(JSContext*, HandleValue);
+  OutOfLineCode* ool = oolCallVM<Fn, ToStringSlow<CanGC>>(
+      lir, ArgList(input), StoreRegisterTo(output));
+
+  Label done;
+  Register tag = masm.extractTag(input, output);
+  const JSAtomState& names = gen->runtime->names();
+
+  // String
+  {
+    Label notString;
+    masm.branchTestString(Assembler::NotEqual, tag, &notString);
+    masm.unboxString(input, output);
+    masm.jump(&done);
+    masm.bind(&notString);
+  }
+
+  // Integer
+  {
+    Label notInteger;
+    masm.branchTestInt32(Assembler::NotEqual, tag, &notInteger);
+    Register unboxed = ToTempUnboxRegister(lir->temp0());
+    unboxed = masm.extractInt32(input, unboxed);
+    emitIntToString(unboxed, output, ool->entry());
+    masm.jump(&done);
+    masm.bind(&notInteger);
+  }
+
+  // Double
+  {
+    // Note: no fastpath. Need two extra registers and can only convert doubles
+    // that fit integers and are smaller than StaticStrings::INT_STATIC_LIMIT.
+    masm.branchTestDouble(Assembler::Equal, tag, ool->entry());
+  }
+
+  // Undefined
+  {
+    Label notUndefined;
+    masm.branchTestUndefined(Assembler::NotEqual, tag, &notUndefined);
+    masm.movePtr(ImmGCPtr(names.undefined), output);
+    masm.jump(&done);
+    masm.bind(&notUndefined);
+  }
+
+  // Null
+  {
+    Label notNull;
+    masm.branchTestNull(Assembler::NotEqual, tag, &notNull);
+    masm.movePtr(ImmGCPtr(names.null), output);
+    masm.jump(&done);
+    masm.bind(&notNull);
+  }
+
+  // Boolean
+  {
+    Label notBoolean, true_;
+    masm.branchTestBoolean(Assembler::NotEqual, tag, &notBoolean);
+    masm.branchTestBooleanTruthy(true, input, &true_);
+    masm.movePtr(ImmGCPtr(names.false_), output);
+    masm.jump(&done);
+    masm.bind(&true_);
+    masm.movePtr(ImmGCPtr(names.true_), output);
+    masm.jump(&done);
+    masm.bind(&notBoolean);
+  }
+
+  // Objects/symbols are only possible when |mir->mightHaveSideEffects()|.
+  if (lir->mir()->mightHaveSideEffects()) {
+    // Object
+    if (lir->mir()->supportSideEffects()) {
+      masm.branchTestObject(Assembler::Equal, tag, ool->entry());
+    } else {
+      // Bail.
+      MOZ_ASSERT(lir->mir()->needsSnapshot());
+      Label bail;
+      masm.branchTestObject(Assembler::Equal, tag, &bail);
+      bailoutFrom(&bail, lir->snapshot());
+    }
+
+    // Symbol
+    if (lir->mir()->supportSideEffects()) {
+      masm.branchTestSymbol(Assembler::Equal, tag, ool->entry());
+    } else {
+      // Bail.
+      MOZ_ASSERT(lir->mir()->needsSnapshot());
+      Label bail;
+      masm.branchTestSymbol(Assembler::Equal, tag, &bail);
+      bailoutFrom(&bail, lir->snapshot());
+    }
+  }
+
+  // BigInt
+  {
+    // No fastpath currently implemented.
+    masm.branchTestBigInt(Assembler::Equal, tag, ool->entry());
+  }
+
+  masm.assumeUnreachable("Unexpected type for LValueToString.");
+
+  masm.bind(&done);
+  masm.bind(ool->rejoin());
+}
+
+using StoreBufferMutationFn = void (*)(js::gc::StoreBuffer*, js::gc::Cell**);
+
+static void EmitStoreBufferMutation(MacroAssembler& masm, Register holder,
+                                    size_t offset, Register buffer,
+                                    LiveGeneralRegisterSet& liveVolatiles,
+                                    StoreBufferMutationFn fun) {
+  Label callVM;
+  Label exit;
+
+  // Call into the VM to barrier the write. The only registers that need to
+  // be preserved are those in liveVolatiles, so once they are saved on the
+  // stack all volatile registers are available for use.
+  masm.bind(&callVM);
+  masm.PushRegsInMask(liveVolatiles);
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::Volatile());
+  regs.takeUnchecked(buffer);
+  regs.takeUnchecked(holder);
+  Register addrReg = regs.takeAny();
+
+  masm.computeEffectiveAddress(Address(holder, offset), addrReg);
+
+  bool needExtraReg = !regs.hasAny<GeneralRegisterSet::DefaultType>();
+  if (needExtraReg) {
+    masm.push(holder);
+    masm.setupUnalignedABICall(holder);
+  } else {
+    masm.setupUnalignedABICall(regs.takeAny());
+  }
+  masm.passABIArg(buffer);
+  masm.passABIArg(addrReg);
+  masm.callWithABI(DynamicFunction<StoreBufferMutationFn>(fun), MoveOp::GENERAL,
+                   CheckUnsafeCallWithABI::DontCheckOther);
+
+  if (needExtraReg) {
+    masm.pop(holder);
+  }
+  masm.PopRegsInMask(liveVolatiles);
+  masm.bind(&exit);
+}
+
+// Warning: this function modifies prev and next.
+static void EmitPostWriteBarrierS(MacroAssembler& masm, Register holder,
+                                  size_t offset, Register prev, Register next,
+                                  LiveGeneralRegisterSet& liveVolatiles) {
+  Label exit;
+  Label checkRemove, putCell;
+
+  // if (next && (buffer = next->storeBuffer()))
+  // but we never pass in nullptr for next.
+  Register storebuffer = next;
+  masm.loadStoreBuffer(next, storebuffer);
+  masm.branchPtr(Assembler::Equal, storebuffer, ImmWord(0), &checkRemove);
+
+  // if (prev && prev->storeBuffer())
+  masm.branchPtr(Assembler::Equal, prev, ImmWord(0), &putCell);
+  masm.loadStoreBuffer(prev, prev);
+  masm.branchPtr(Assembler::NotEqual, prev, ImmWord(0), &exit);
+
+  // buffer->putCell(cellp)
+  masm.bind(&putCell);
+  EmitStoreBufferMutation(masm, holder, offset, storebuffer, liveVolatiles,
+                          JSString::addCellAddressToStoreBuffer);
+  masm.jump(&exit);
+
+  // if (prev && (buffer = prev->storeBuffer()))
+  masm.bind(&checkRemove);
+  masm.branchPtr(Assembler::Equal, prev, ImmWord(0), &exit);
+  masm.loadStoreBuffer(prev, storebuffer);
+  masm.branchPtr(Assembler::Equal, storebuffer, ImmWord(0), &exit);
+  EmitStoreBufferMutation(masm, holder, offset, storebuffer, liveVolatiles,
+                          JSString::removeCellAddressFromStoreBuffer);
+
+  masm.bind(&exit);
+}
+
+void CodeGenerator::visitRegExp(LRegExp* lir) {
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+  JSObject* source = lir->mir()->source();
+
+  using Fn = JSObject* (*)(JSContext*, Handle<RegExpObject*>);
+  OutOfLineCode* ool = oolCallVM<Fn, CloneRegExpObject>(
+      lir, ArgList(ImmGCPtr(source)), StoreRegisterTo(output));
+  if (lir->mir()->hasShared()) {
+    TemplateObject templateObject(source);
+    masm.createGCObject(output, temp, templateObject, gc::Heap::Default,
+                        ool->entry());
+  } else {
+    masm.jump(ool->entry());
+  }
+  masm.bind(ool->rejoin());
+}
+
+static constexpr int32_t RegExpPairsVectorStartOffset(
+    int32_t inputOutputDataStartOffset) {
+  return inputOutputDataStartOffset + int32_t(InputOutputDataSize) +
+         int32_t(sizeof(MatchPairs));
+}
+
+static Address RegExpPairCountAddress(MacroAssembler& masm,
+                                      int32_t inputOutputDataStartOffset) {
+  return Address(FramePointer, inputOutputDataStartOffset +
+                                   int32_t(InputOutputDataSize) +
+                                   MatchPairs::offsetOfPairCount());
+}
+
+// When the unicode flag is set, if lastIndex points to a trail
+// surrogate, we should step back to the corresponding lead surrogate.
+// See ExecuteRegExp in builtin/RegExp.cpp for more detail.
+static void StepBackToLeadSurrogate(MacroAssembler& masm, Register regexpShared,
+                                    Register input, Register lastIndex,
+                                    Register temp1, Register temp2) {
+  Label done;
+
+  // If the unicode flag is not set, there is nothing to do.
+  masm.branchTest32(Assembler::Zero,
+                    Address(regexpShared, RegExpShared::offsetOfFlags()),
+                    Imm32(int32_t(JS::RegExpFlag::Unicode)), &done);
+
+  // If the input is latin1, there can't be any surrogates.
+  masm.branchLatin1String(input, &done);
+
+  // Check if |lastIndex > 0 && lastIndex < input->length()|.
+  // lastIndex should already have no sign here.
+  masm.branchTest32(Assembler::Zero, lastIndex, lastIndex, &done);
+  masm.loadStringLength(input, temp1);
+  masm.branch32(Assembler::AboveOrEqual, lastIndex, temp1, &done);
+
+  // For TrailSurrogateMin ≤ x ≤ TrailSurrogateMax and
+  // LeadSurrogateMin ≤ x ≤ LeadSurrogateMax, the following
+  // equations hold.
+  //
+  //    SurrogateMin ≤ x ≤ SurrogateMax
+  // <> SurrogateMin ≤ x ≤ SurrogateMin + 2^10 - 1
+  // <> ((x - SurrogateMin) >>> 10) = 0    where >>> is an unsigned-shift
+  // See Hacker's Delight, section 4-1 for details.
+  //
+  //    ((x - SurrogateMin) >>> 10) = 0
+  // <> floor((x - SurrogateMin) / 1024) = 0
+  // <> floor((x / 1024) - (SurrogateMin / 1024)) = 0
+  // <> floor(x / 1024) = SurrogateMin / 1024
+  // <> floor(x / 1024) * 1024 = SurrogateMin
+  // <> (x >>> 10) << 10 = SurrogateMin
+  // <> x & ~(2^10 - 1) = SurrogateMin
+
+  constexpr char16_t SurrogateMask = 0xFC00;
+
+  Register charsReg = temp1;
+  masm.loadStringChars(input, charsReg, CharEncoding::TwoByte);
+
+  // Check if input[lastIndex] is trail surrogate.
+  masm.loadChar(charsReg, lastIndex, temp2, CharEncoding::TwoByte);
+  masm.and32(Imm32(SurrogateMask), temp2);
+  masm.branch32(Assembler::NotEqual, temp2, Imm32(unicode::TrailSurrogateMin),
+                &done);
+
+  // Check if input[lastIndex-1] is lead surrogate.
+  masm.loadChar(charsReg, lastIndex, temp2, CharEncoding::TwoByte,
+                -int32_t(sizeof(char16_t)));
+  masm.and32(Imm32(SurrogateMask), temp2);
+  masm.branch32(Assembler::NotEqual, temp2, Imm32(unicode::LeadSurrogateMin),
+                &done);
+
+  // Move lastIndex back to lead surrogate.
+  masm.sub32(Imm32(1), lastIndex);
+
+  masm.bind(&done);
+}
+
+static void UpdateRegExpStatics(MacroAssembler& masm, Register regexp,
+                                Register input, Register lastIndex,
+                                Register staticsReg, Register temp1,
+                                Register temp2, gc::Heap initialStringHeap,
+                                LiveGeneralRegisterSet& volatileRegs) {
+  Address pendingInputAddress(staticsReg,
+                              RegExpStatics::offsetOfPendingInput());
+  Address matchesInputAddress(staticsReg,
+                              RegExpStatics::offsetOfMatchesInput());
+  Address lazySourceAddress(staticsReg, RegExpStatics::offsetOfLazySource());
+  Address lazyIndexAddress(staticsReg, RegExpStatics::offsetOfLazyIndex());
+
+  masm.guardedCallPreBarrier(pendingInputAddress, MIRType::String);
+  masm.guardedCallPreBarrier(matchesInputAddress, MIRType::String);
+  masm.guardedCallPreBarrier(lazySourceAddress, MIRType::String);
+
+  if (initialStringHeap == gc::Heap::Default) {
+    // Writing into RegExpStatics tenured memory; must post-barrier.
+    if (staticsReg.volatile_()) {
+      volatileRegs.add(staticsReg);
+    }
+
+    masm.loadPtr(pendingInputAddress, temp1);
+    masm.storePtr(input, pendingInputAddress);
+    masm.movePtr(input, temp2);
+    EmitPostWriteBarrierS(masm, staticsReg,
+                          RegExpStatics::offsetOfPendingInput(),
+                          temp1 /* prev */, temp2 /* next */, volatileRegs);
+
+    masm.loadPtr(matchesInputAddress, temp1);
+    masm.storePtr(input, matchesInputAddress);
+    masm.movePtr(input, temp2);
+    EmitPostWriteBarrierS(masm, staticsReg,
+                          RegExpStatics::offsetOfMatchesInput(),
+                          temp1 /* prev */, temp2 /* next */, volatileRegs);
+  } else {
+    masm.storePtr(input, pendingInputAddress);
+    masm.storePtr(input, matchesInputAddress);
+  }
+
+  masm.storePtr(lastIndex,
+                Address(staticsReg, RegExpStatics::offsetOfLazyIndex()));
+  masm.store32(
+      Imm32(1),
+      Address(staticsReg, RegExpStatics::offsetOfPendingLazyEvaluation()));
+
+  masm.unboxNonDouble(Address(regexp, NativeObject::getFixedSlotOffset(
+                                          RegExpObject::SHARED_SLOT)),
+                      temp1, JSVAL_TYPE_PRIVATE_GCTHING);
+  masm.loadPtr(Address(temp1, RegExpShared::offsetOfSource()), temp2);
+  masm.storePtr(temp2, lazySourceAddress);
+  static_assert(sizeof(JS::RegExpFlags) == 1, "load size must match flag size");
+  masm.load8ZeroExtend(Address(temp1, RegExpShared::offsetOfFlags()), temp2);
+  masm.store8(temp2, Address(staticsReg, RegExpStatics::offsetOfLazyFlags()));
+}
+
+// Prepare an InputOutputData and optional MatchPairs which space has been
+// allocated for on the stack, and try to execute a RegExp on a string input.
+// If the RegExp was successfully executed and matched the input, fallthrough.
+// Otherwise, jump to notFound or failure.
+//
+// inputOutputDataStartOffset is the offset relative to the frame pointer
+// register. This offset is negative for the RegExpExecTest stub.
+static bool PrepareAndExecuteRegExp(JSContext* cx, MacroAssembler& masm,
+                                    Register regexp, Register input,
+                                    Register lastIndex, Register temp1,
+                                    Register temp2, Register temp3,
+                                    int32_t inputOutputDataStartOffset,
+                                    gc::Heap initialStringHeap, Label* notFound,
+                                    Label* failure) {
+  JitSpew(JitSpew_Codegen, "# Emitting PrepareAndExecuteRegExp");
+
+  using irregexp::InputOutputData;
+
+  /*
+   * [SMDOC] Stack layout for PrepareAndExecuteRegExp
+   *
+   * Before this function is called, the caller is responsible for
+   * allocating enough stack space for the following data:
+   *
+   * inputOutputDataStartOffset +-----> +---------------+
+   *                                    |InputOutputData|
+   *          inputStartAddress +---------->  inputStart|
+   *            inputEndAddress +---------->    inputEnd|
+   *          startIndexAddress +---------->  startIndex|
+   *             matchesAddress +---------->     matches|-----+
+   *                                    +---------------+     |
+   * matchPairs(Address|Offset) +-----> +---------------+  <--+
+   *                                    |  MatchPairs   |
+   *           pairCountAddress +---------->    count   |
+   *        pairsPointerAddress +---------->    pairs   |-----+
+   *                                    +---------------+     |
+   * pairsArray(Address|Offset) +-----> +---------------+  <--+
+   *                                    |   MatchPair   |
+   *     firstMatchStartAddress +---------->    start   |  <--+
+   *                                    |       limit   |     |
+   *                                    +---------------+     |
+   *                                           .              |
+   *                                           .  Reserved space for
+   *                                           .  RegExpObject::MaxPairCount
+   *                                           .  MatchPair objects
+   *                                           .              |
+   *                                    +---------------+     |
+   *                                    |   MatchPair   |     |
+   *                                    |       start   |     |
+   *                                    |       limit   |  <--+
+   *                                    +---------------+
+   */
+
+  int32_t ioOffset = inputOutputDataStartOffset;
+  int32_t matchPairsOffset = ioOffset + int32_t(sizeof(InputOutputData));
+  int32_t pairsArrayOffset = matchPairsOffset + int32_t(sizeof(MatchPairs));
+
+  Address inputStartAddress(FramePointer,
+                            ioOffset + InputOutputData::offsetOfInputStart());
+  Address inputEndAddress(FramePointer,
+                          ioOffset + InputOutputData::offsetOfInputEnd());
+  Address startIndexAddress(FramePointer,
+                            ioOffset + InputOutputData::offsetOfStartIndex());
+  Address matchesAddress(FramePointer,
+                         ioOffset + InputOutputData::offsetOfMatches());
+
+  Address matchPairsAddress(FramePointer, matchPairsOffset);
+  Address pairCountAddress(FramePointer,
+                           matchPairsOffset + MatchPairs::offsetOfPairCount());
+  Address pairsPointerAddress(FramePointer,
+                              matchPairsOffset + MatchPairs::offsetOfPairs());
+
+  Address pairsArrayAddress(FramePointer, pairsArrayOffset);
+  Address firstMatchStartAddress(FramePointer,
+                                 pairsArrayOffset + MatchPair::offsetOfStart());
+
+  // First, fill in a skeletal MatchPairs instance on the stack. This will be
+  // passed to the OOL stub in the caller if we aren't able to execute the
+  // RegExp inline, and that stub needs to be able to determine whether the
+  // execution finished successfully.
+
+  // Initialize MatchPairs::pairCount to 1. The correct value can only
+  // be determined after loading the RegExpShared. If the RegExpShared
+  // has Kind::Atom, this is the correct pairCount.
+  masm.store32(Imm32(1), pairCountAddress);
+
+  // Initialize MatchPairs::pairs pointer
+  masm.computeEffectiveAddress(pairsArrayAddress, temp1);
+  masm.storePtr(temp1, pairsPointerAddress);
+
+  // Initialize MatchPairs::pairs[0]::start to MatchPair::NoMatch
+  masm.store32(Imm32(MatchPair::NoMatch), firstMatchStartAddress);
+
+  // Determine the set of volatile inputs to save when calling into C++ or
+  // regexp code.
+  LiveGeneralRegisterSet volatileRegs;
+  if (lastIndex.volatile_()) {
+    volatileRegs.add(lastIndex);
+  }
+  if (input.volatile_()) {
+    volatileRegs.add(input);
+  }
+  if (regexp.volatile_()) {
+    volatileRegs.add(regexp);
+  }
+
+  // Ensure the input string is not a rope.
+  Label isLinear;
+  masm.branchIfNotRope(input, &isLinear);
+  {
+    masm.PushRegsInMask(volatileRegs);
+
+    using Fn = JSLinearString* (*)(JSString*);
+    masm.setupUnalignedABICall(temp1);
+    masm.passABIArg(input);
+    masm.callWithABI<Fn, js::jit::LinearizeForCharAccessPure>();
+
+    MOZ_ASSERT(!volatileRegs.has(temp1));
+    masm.storeCallPointerResult(temp1);
+    masm.PopRegsInMask(volatileRegs);
+
+    masm.branchTestPtr(Assembler::Zero, temp1, temp1, failure);
+  }
+  masm.bind(&isLinear);
+
+  // Load the RegExpShared.
+  Register regexpReg = temp1;
+  Address sharedSlot = Address(
+      regexp, NativeObject::getFixedSlotOffset(RegExpObject::SHARED_SLOT));
+  masm.branchTestUndefined(Assembler::Equal, sharedSlot, failure);
+  masm.unboxNonDouble(sharedSlot, regexpReg, JSVAL_TYPE_PRIVATE_GCTHING);
+
+  // Handle Atom matches
+  Label notAtom, checkSuccess;
+  masm.branchPtr(Assembler::Equal,
+                 Address(regexpReg, RegExpShared::offsetOfPatternAtom()),
+                 ImmWord(0), &notAtom);
+  {
+    masm.computeEffectiveAddress(matchPairsAddress, temp3);
+
+    masm.PushRegsInMask(volatileRegs);
+    using Fn = RegExpRunStatus (*)(RegExpShared* re, JSLinearString* input,
+                                   size_t start, MatchPairs* matchPairs);
+    masm.setupUnalignedABICall(temp2);
+    masm.passABIArg(regexpReg);
+    masm.passABIArg(input);
+    masm.passABIArg(lastIndex);
+    masm.passABIArg(temp3);
+    masm.callWithABI<Fn, js::ExecuteRegExpAtomRaw>();
+
+    MOZ_ASSERT(!volatileRegs.has(temp1));
+    masm.storeCallInt32Result(temp1);
+    masm.PopRegsInMask(volatileRegs);
+
+    masm.jump(&checkSuccess);
+  }
+  masm.bind(&notAtom);
+
+  // Don't handle regexps with too many capture pairs.
+  masm.load32(Address(regexpReg, RegExpShared::offsetOfPairCount()), temp2);
+  masm.branch32(Assembler::Above, temp2, Imm32(RegExpObject::MaxPairCount),
+                failure);
+
+  // Fill in the pair count in the MatchPairs on the stack.
+  masm.store32(temp2, pairCountAddress);
+
+  // Update lastIndex if necessary.
+  StepBackToLeadSurrogate(masm, regexpReg, input, lastIndex, temp2, temp3);
+
+  // Load code pointer and length of input (in bytes).
+  // Store the input start in the InputOutputData.
+  Register codePointer = temp1;  // Note: temp1 was previously regexpReg.
+  Register byteLength = temp3;
+  {
+    Label isLatin1, done;
+    masm.loadStringLength(input, byteLength);
+
+    masm.branchLatin1String(input, &isLatin1);
+
+    // Two-byte input
+    masm.loadStringChars(input, temp2, CharEncoding::TwoByte);
+    masm.storePtr(temp2, inputStartAddress);
+    masm.loadPtr(
+        Address(regexpReg, RegExpShared::offsetOfJitCode(/*latin1 =*/false)),
+        codePointer);
+    masm.lshiftPtr(Imm32(1), byteLength);
+    masm.jump(&done);
+
+    // Latin1 input
+    masm.bind(&isLatin1);
+    masm.loadStringChars(input, temp2, CharEncoding::Latin1);
+    masm.storePtr(temp2, inputStartAddress);
+    masm.loadPtr(
+        Address(regexpReg, RegExpShared::offsetOfJitCode(/*latin1 =*/true)),
+        codePointer);
+
+    masm.bind(&done);
+
+    // Store end pointer
+    masm.addPtr(byteLength, temp2);
+    masm.storePtr(temp2, inputEndAddress);
+  }
+
+  // Guard that the RegExpShared has been compiled for this type of input.
+  // If it has not been compiled, we fall back to the OOL case, which will
+  // do a VM call into the interpreter.
+  // TODO: add an interpreter trampoline?
+  masm.branchPtr(Assembler::Equal, codePointer, ImmWord(0), failure);
+  masm.loadPtr(Address(codePointer, JitCode::offsetOfCode()), codePointer);
+
+  // Finish filling in the InputOutputData instance on the stack
+  masm.computeEffectiveAddress(matchPairsAddress, temp2);
+  masm.storePtr(temp2, matchesAddress);
+  masm.storePtr(lastIndex, startIndexAddress);
+
+  // Execute the RegExp.
+  masm.computeEffectiveAddress(
+      Address(FramePointer, inputOutputDataStartOffset), temp2);
+  masm.PushRegsInMask(volatileRegs);
+  masm.setupUnalignedABICall(temp3);
+  masm.passABIArg(temp2);
+  masm.callWithABI(codePointer);
+  masm.storeCallInt32Result(temp1);
+  masm.PopRegsInMask(volatileRegs);
+
+  masm.bind(&checkSuccess);
+  masm.branch32(Assembler::Equal, temp1,
+                Imm32(RegExpRunStatus_Success_NotFound), notFound);
+  masm.branch32(Assembler::Equal, temp1, Imm32(RegExpRunStatus_Error), failure);
+
+  // Lazily update the RegExpStatics.
+  RegExpStatics* res = GlobalObject::getRegExpStatics(cx, cx->global());
+  if (!res) {
+    return false;
+  }
+  masm.movePtr(ImmPtr(res), temp1);
+  UpdateRegExpStatics(masm, regexp, input, lastIndex, temp1, temp2, temp3,
+                      initialStringHeap, volatileRegs);
+
+  return true;
+}
+
+static void CopyStringChars(MacroAssembler& masm, Register to, Register from,
+                            Register len, Register byteOpScratch,
+                            CharEncoding encoding);
+
+class CreateDependentString {
+  CharEncoding encoding_;
+  Register string_;
+  Register temp1_;
+  Register temp2_;
+  Label* failure_;
+
+  enum class FallbackKind : uint8_t {
+    InlineString,
+    FatInlineString,
+    NotInlineString,
+    Count
+  };
+  mozilla::EnumeratedArray<FallbackKind, FallbackKind::Count, Label> fallbacks_,
+      joins_;
+
+ public:
+  CreateDependentString(CharEncoding encoding, Register string, Register temp1,
+                        Register temp2, Label* failure)
+      : encoding_(encoding),
+        string_(string),
+        temp1_(temp1),
+        temp2_(temp2),
+        failure_(failure) {}
+
+  Register string() const { return string_; }
+  CharEncoding encoding() const { return encoding_; }
+
+  // Generate code that creates DependentString.
+  // Caller should call generateFallback after masm.ret(), to generate
+  // fallback path.
+  void generate(MacroAssembler& masm, const JSAtomState& names,
+                CompileRuntime* runtime, Register base,
+                BaseIndex startIndexAddress, BaseIndex limitIndexAddress,
+                gc::Heap initialStringHeap);
+
+  // Generate fallback path for creating DependentString.
+  void generateFallback(MacroAssembler& masm);
+};
+
+void CreateDependentString::generate(MacroAssembler& masm,
+                                     const JSAtomState& names,
+                                     CompileRuntime* runtime, Register base,
+                                     BaseIndex startIndexAddress,
+                                     BaseIndex limitIndexAddress,
+                                     gc::Heap initialStringHeap) {
+  JitSpew(JitSpew_Codegen, "# Emitting CreateDependentString (encoding=%s)",
+          (encoding_ == CharEncoding::Latin1 ? "Latin-1" : "Two-Byte"));
+
+  auto newGCString = [&](FallbackKind kind) {
+    uint32_t flags = kind == FallbackKind::InlineString
+                         ? JSString::INIT_THIN_INLINE_FLAGS
+                     : kind == FallbackKind::FatInlineString
+                         ? JSString::INIT_FAT_INLINE_FLAGS
+                         : JSString::INIT_DEPENDENT_FLAGS;
+    if (encoding_ == CharEncoding::Latin1) {
+      flags |= JSString::LATIN1_CHARS_BIT;
+    }
+
+    if (kind != FallbackKind::FatInlineString) {
+      masm.newGCString(string_, temp2_, initialStringHeap, &fallbacks_[kind]);
+    } else {
+      masm.newGCFatInlineString(string_, temp2_, initialStringHeap,
+                                &fallbacks_[kind]);
+    }
+    masm.bind(&joins_[kind]);
+    masm.store32(Imm32(flags), Address(string_, JSString::offsetOfFlags()));
+  };
+
+  // Compute the string length.
+  masm.load32(startIndexAddress, temp2_);
+  masm.load32(limitIndexAddress, temp1_);
+  masm.sub32(temp2_, temp1_);
+
+  Label done, nonEmpty;
+
+  // Zero length matches use the empty string.
+  masm.branchTest32(Assembler::NonZero, temp1_, temp1_, &nonEmpty);
+  masm.movePtr(ImmGCPtr(names.empty), string_);
+  masm.jump(&done);
+
+  masm.bind(&nonEmpty);
+
+  // Complete matches use the base string.
+  Label nonBaseStringMatch;
+  masm.branchTest32(Assembler::NonZero, temp2_, temp2_, &nonBaseStringMatch);
+  masm.branch32(Assembler::NotEqual, Address(base, JSString::offsetOfLength()),
+                temp1_, &nonBaseStringMatch);
+  masm.movePtr(base, string_);
+  masm.jump(&done);
+
+  masm.bind(&nonBaseStringMatch);
+
+  Label notInline;
+
+  int32_t maxInlineLength = encoding_ == CharEncoding::Latin1
+                                ? JSFatInlineString::MAX_LENGTH_LATIN1
+                                : JSFatInlineString::MAX_LENGTH_TWO_BYTE;
+  masm.branch32(Assembler::Above, temp1_, Imm32(maxInlineLength), &notInline);
+  {
+    // Make a thin or fat inline string.
+    Label stringAllocated, fatInline;
+
+    int32_t maxThinInlineLength = encoding_ == CharEncoding::Latin1
+                                      ? JSThinInlineString::MAX_LENGTH_LATIN1
+                                      : JSThinInlineString::MAX_LENGTH_TWO_BYTE;
+    masm.branch32(Assembler::Above, temp1_, Imm32(maxThinInlineLength),
+                  &fatInline);
+    if (encoding_ == CharEncoding::Latin1) {
+      // One character Latin-1 strings can be loaded directly from the
+      // static strings table.
+      Label thinInline;
+      masm.branch32(Assembler::Above, temp1_, Imm32(1), &thinInline);
+      {
+        static_assert(
+            StaticStrings::UNIT_STATIC_LIMIT - 1 == JSString::MAX_LATIN1_CHAR,
+            "Latin-1 strings can be loaded from static strings");
+
+        masm.loadStringChars(base, temp1_, encoding_);
+        masm.loadChar(temp1_, temp2_, temp1_, encoding_);
+
+        masm.movePtr(ImmPtr(&runtime->staticStrings().unitStaticTable),
+                     string_);
+        masm.loadPtr(BaseIndex(string_, temp1_, ScalePointer), string_);
+
+        masm.jump(&done);
+      }
+      masm.bind(&thinInline);
+    }
+    {
+      newGCString(FallbackKind::InlineString);
+      masm.jump(&stringAllocated);
+    }
+    masm.bind(&fatInline);
+    { newGCString(FallbackKind::FatInlineString); }
+    masm.bind(&stringAllocated);
+
+    masm.store32(temp1_, Address(string_, JSString::offsetOfLength()));
+
+    masm.push(string_);
+    masm.push(base);
+
+    MOZ_ASSERT(startIndexAddress.base == FramePointer,
+               "startIndexAddress is still valid after stack pushes");
+
+    // Load chars pointer for the new string.
+    masm.loadInlineStringCharsForStore(string_, string_);
+
+    // Load the source characters pointer.
+    masm.loadStringChars(base, temp2_, encoding_);
+    masm.load32(startIndexAddress, base);
+    masm.addToCharPtr(temp2_, base, encoding_);
+
+    CopyStringChars(masm, string_, temp2_, temp1_, base, encoding_);
+
+    masm.pop(base);
+    masm.pop(string_);
+
+    masm.jump(&done);
+  }
+
+  masm.bind(&notInline);
+
+  {
+    // Make a dependent string.
+    // Warning: string may be tenured (if the fallback case is hit), so
+    // stores into it must be post barriered.
+    newGCString(FallbackKind::NotInlineString);
+
+    masm.store32(temp1_, Address(string_, JSString::offsetOfLength()));
+
+    masm.loadNonInlineStringChars(base, temp1_, encoding_);
+    masm.load32(startIndexAddress, temp2_);
+    masm.addToCharPtr(temp1_, temp2_, encoding_);
+    masm.storeNonInlineStringChars(temp1_, string_);
+    masm.storeDependentStringBase(base, string_);
+    masm.movePtr(base, temp1_);
+
+    // Follow any base pointer if the input is itself a dependent string.
+    // Watch for undepended strings, which have a base pointer but don't
+    // actually share their characters with it.
+    Label noBase;
+    masm.load32(Address(base, JSString::offsetOfFlags()), temp2_);
+    masm.and32(Imm32(JSString::TYPE_FLAGS_MASK), temp2_);
+    masm.branchTest32(Assembler::Zero, temp2_, Imm32(JSString::DEPENDENT_BIT),
+                      &noBase);
+    masm.loadDependentStringBase(base, temp1_);
+    masm.storeDependentStringBase(temp1_, string_);
+    masm.bind(&noBase);
+
+    // Post-barrier the base store, whether it was the direct or indirect
+    // base (both will end up in temp1 here).
+    masm.branchPtrInNurseryChunk(Assembler::Equal, string_, temp2_, &done);
+    masm.branchPtrInNurseryChunk(Assembler::NotEqual, temp1_, temp2_, &done);
+
+    LiveRegisterSet regsToSave(RegisterSet::Volatile());
+    regsToSave.takeUnchecked(temp1_);
+    regsToSave.takeUnchecked(temp2_);
+
+    masm.PushRegsInMask(regsToSave);
+
+    masm.mov(ImmPtr(runtime), temp1_);
+
+    using Fn = void (*)(JSRuntime* rt, js::gc::Cell* cell);
+    masm.setupUnalignedABICall(temp2_);
+    masm.passABIArg(temp1_);
+    masm.passABIArg(string_);
+    masm.callWithABI<Fn, PostWriteBarrier>();
+
+    masm.PopRegsInMask(regsToSave);
+  }
+
+  masm.bind(&done);
+}
+
+void CreateDependentString::generateFallback(MacroAssembler& masm) {
+  JitSpew(JitSpew_Codegen,
+          "# Emitting CreateDependentString fallback (encoding=%s)",
+          (encoding_ == CharEncoding::Latin1 ? "Latin-1" : "Two-Byte"));
+
+  LiveRegisterSet regsToSave(RegisterSet::Volatile());
+  regsToSave.takeUnchecked(string_);
+  regsToSave.takeUnchecked(temp2_);
+
+  for (FallbackKind kind : mozilla::MakeEnumeratedRange(FallbackKind::Count)) {
+    masm.bind(&fallbacks_[kind]);
+
+    masm.PushRegsInMask(regsToSave);
+
+    using Fn = void* (*)(JSContext* cx);
+    masm.setupUnalignedABICall(string_);
+    masm.loadJSContext(string_);
+    masm.passABIArg(string_);
+    if (kind == FallbackKind::FatInlineString) {
+      masm.callWithABI<Fn, AllocateFatInlineString>();
+    } else {
+      masm.callWithABI<Fn, AllocateDependentString>();
+    }
+    masm.storeCallPointerResult(string_);
+
+    masm.PopRegsInMask(regsToSave);
+
+    masm.branchPtr(Assembler::Equal, string_, ImmWord(0), failure_);
+
+    masm.jump(&joins_[kind]);
+  }
+}
+
+static void CreateMatchResultFallback(MacroAssembler& masm, Register object,
+                                      Register temp1, Register temp2,
+                                      const TemplateObject& templateObject,
+                                      Label* fail) {
+  JitSpew(JitSpew_Codegen, "# Emitting CreateMatchResult fallback");
+
+  MOZ_ASSERT(templateObject.isArrayObject());
+
+  LiveRegisterSet regsToSave(RegisterSet::Volatile());
+  regsToSave.takeUnchecked(object);
+  regsToSave.takeUnchecked(temp1);
+  regsToSave.takeUnchecked(temp2);
+
+  masm.PushRegsInMask(regsToSave);
+
+  using Fn = void* (*)(JSContext* cx, gc::AllocKind kind, size_t nDynamicSlots);
+  masm.setupUnalignedABICall(object);
+
+  masm.loadJSContext(object);
+  masm.passABIArg(object);
+  masm.move32(Imm32(int32_t(templateObject.getAllocKind())), temp1);
+  masm.passABIArg(temp1);
+  masm.move32(
+      Imm32(int32_t(templateObject.asTemplateNativeObject().numDynamicSlots())),
+      temp2);
+  masm.passABIArg(temp2);
+  masm.callWithABI<Fn, CreateMatchResultFallbackFunc>();
+  masm.storeCallPointerResult(object);
+
+  masm.PopRegsInMask(regsToSave);
+
+  masm.branchPtr(Assembler::Equal, object, ImmWord(0), fail);
+
+  masm.initGCThing(object, temp1, templateObject);
+}
+
+// Generate the RegExpMatcher and RegExpExecMatch stubs. These are very similar,
+// but RegExpExecMatch also has to load and update .lastIndex for global/sticky
+// regular expressions.
+static JitCode* GenerateRegExpMatchStubShared(JSContext* cx, bool isExecMatch) {
+  if (isExecMatch) {
+    JitSpew(JitSpew_Codegen, "# Emitting RegExpExecMatch stub");
+  } else {
+    JitSpew(JitSpew_Codegen, "# Emitting RegExpMatcher stub");
+  }
+
+  Register regexp = RegExpMatcherRegExpReg;
+  Register input = RegExpMatcherStringReg;
+  Register lastIndex = RegExpMatcherLastIndexReg;
+  ValueOperand result = JSReturnOperand;
+
+  // We are free to clobber all registers, as LRegExpMatcher is a call
+  // instruction.
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+  regs.take(input);
+  regs.take(regexp);
+  regs.take(lastIndex);
+
+  Register temp1 = regs.takeAny();
+  Register temp2 = regs.takeAny();
+  Register temp3 = regs.takeAny();
+  Register maybeTemp4 = InvalidReg;
+  if (!regs.empty()) {
+    // There are not enough registers on x86.
+    maybeTemp4 = regs.takeAny();
+  }
+  Register maybeTemp5 = InvalidReg;
+  if (!regs.empty()) {
+    // There are not enough registers on x86.
+    maybeTemp5 = regs.takeAny();
+  }
+
+  Address flagsSlot(regexp, RegExpObject::offsetOfFlags());
+  Address lastIndexSlot(regexp, RegExpObject::offsetOfLastIndex());
+
+  ArrayObject* templateObject =
+      cx->realm()->regExps.getOrCreateMatchResultTemplateObject(cx);
+  if (!templateObject) {
+    return nullptr;
+  }
+  TemplateObject templateObj(templateObject);
+  const TemplateNativeObject& nativeTemplateObj =
+      templateObj.asTemplateNativeObject();
+
+  // The template object should have enough space for the maximum number of
+  // pairs this stub can handle.
+  MOZ_ASSERT(ObjectElements::VALUES_PER_HEADER + RegExpObject::MaxPairCount ==
+             gc::GetGCKindSlots(templateObj.getAllocKind()));
+
+  TempAllocator temp(&cx->tempLifoAlloc());
+  JitContext jcx(cx);
+  StackMacroAssembler masm(cx, temp);
+  AutoCreatedBy acb(masm, "GenerateRegExpMatchStubShared");
+
+#ifdef JS_USE_LINK_REGISTER
+  masm.pushReturnAddress();
+#endif
+  masm.push(FramePointer);
+  masm.moveStackPtrTo(FramePointer);
+
+  Label notFoundZeroLastIndex;
+  if (isExecMatch) {
+    masm.loadRegExpLastIndex(regexp, input, lastIndex, &notFoundZeroLastIndex);
+  }
+
+  // The InputOutputData is placed above the frame pointer and return address on
+  // the stack.
+  int32_t inputOutputDataStartOffset = 2 * sizeof(void*);
+
+  JS::AutoAssertNoGC nogc(cx);
+  gc::Heap initialStringHeap = cx->realm()->jitRealm()->getInitialStringHeap();
+
+  Label notFound, oolEntry;
+  if (!PrepareAndExecuteRegExp(cx, masm, regexp, input, lastIndex, temp1, temp2,
+                               temp3, inputOutputDataStartOffset,
+                               initialStringHeap, &notFound, &oolEntry)) {
+    return nullptr;
+  }
+
+  // If a regexp has named captures, fall back to the OOL stub, which
+  // will end up calling CreateRegExpMatchResults.
+  Register shared = temp2;
+  masm.unboxNonDouble(Address(regexp, NativeObject::getFixedSlotOffset(
+                                          RegExpObject::SHARED_SLOT)),
+                      shared, JSVAL_TYPE_PRIVATE_GCTHING);
+  masm.branchPtr(Assembler::NotEqual,
+                 Address(shared, RegExpShared::offsetOfGroupsTemplate()),
+                 ImmWord(0), &oolEntry);
+
+  // Similarly, if the |hasIndices| flag is set, fall back to the OOL stub.
+  masm.branchTest32(Assembler::NonZero,
+                    Address(shared, RegExpShared::offsetOfFlags()),
+                    Imm32(int32_t(JS::RegExpFlag::HasIndices)), &oolEntry);
+
+  // Construct the result.
+  Register object = temp1;
+  Label matchResultFallback, matchResultJoin;
+  masm.createGCObject(object, temp2, templateObj, gc::Heap::Default,
+                      &matchResultFallback);
+  masm.bind(&matchResultJoin);
+
+  MOZ_ASSERT(nativeTemplateObj.numFixedSlots() == 0);
+  // Dynamic slot count is always two less than a power of 2.
+  MOZ_ASSERT(nativeTemplateObj.numDynamicSlots() == 6);
+  static_assert(RegExpRealm::MatchResultObjectIndexSlot == 0,
+                "First slot holds the 'index' property");
+  static_assert(RegExpRealm::MatchResultObjectInputSlot == 1,
+                "Second slot holds the 'input' property");
+  static_assert(RegExpRealm::MatchResultObjectGroupsSlot == 2,
+                "Third slot holds the 'groups' property");
+
+  // Initialize the slots of the result object with the dummy values
+  // defined in createMatchResultTemplateObject.
+  masm.loadPtr(Address(object, NativeObject::offsetOfSlots()), temp2);
+  masm.storeValue(
+      nativeTemplateObj.getSlot(RegExpRealm::MatchResultObjectIndexSlot),
+      Address(temp2, RegExpRealm::offsetOfMatchResultObjectIndexSlot()));
+  masm.storeValue(
+      nativeTemplateObj.getSlot(RegExpRealm::MatchResultObjectInputSlot),
+      Address(temp2, RegExpRealm::offsetOfMatchResultObjectInputSlot()));
+  masm.storeValue(
+      nativeTemplateObj.getSlot(RegExpRealm::MatchResultObjectGroupsSlot),
+      Address(temp2, RegExpRealm::offsetOfMatchResultObjectGroupsSlot()));
+
+  // clang-format off
+   /*
+    * [SMDOC] Stack layout for the RegExpMatcher stub
+    *
+    *                                    +---------------+
+    *               FramePointer +-----> |Caller-FramePtr|
+    *                                    +---------------+
+    *                                    |Return-Address |
+    *                                    +---------------+
+    * inputOutputDataStartOffset +-----> +---------------+
+    *                                    |InputOutputData|
+    *                                    +---------------+
+    *                                    +---------------+
+    *                                    |  MatchPairs   |
+    *           pairsCountAddress +----------->  count   |
+    *                                    |       pairs   |
+    *                                    |               |
+    *                                    +---------------+
+    *     pairsVectorStartOffset +-----> +---------------+
+    *                                    |   MatchPair   |
+    *             matchPairStart +------------>  start   |  <-------+
+    *             matchPairLimit +------------>  limit   |          | Reserved space for
+    *                                    +---------------+          | `RegExpObject::MaxPairCount`
+    *                                           .                   | MatchPair objects.
+    *                                           .                   |
+    *                                           .                   | `count` objects will be
+    *                                    +---------------+          | initialized and can be
+    *                                    |   MatchPair   |          | accessed below.
+    *                                    |       start   |  <-------+
+    *                                    |       limit   |
+    *                                    +---------------+
+    */
+  // clang-format on
+
+  static_assert(sizeof(MatchPair) == 2 * sizeof(int32_t),
+                "MatchPair consists of two int32 values representing the start"
+                "and the end offset of the match");
+
+  Address pairCountAddress =
+      RegExpPairCountAddress(masm, inputOutputDataStartOffset);
+
+  int32_t pairsVectorStartOffset =
+      RegExpPairsVectorStartOffset(inputOutputDataStartOffset);
+
+  // Incremented by one below for each match pair.
+  Register matchIndex = temp2;
+  masm.move32(Imm32(0), matchIndex);
+
+  // The element in which to store the result of the current match.
+  size_t elementsOffset = NativeObject::offsetOfFixedElements();
+  BaseObjectElementIndex objectMatchElement(object, matchIndex, elementsOffset);
+
+  // The current match pair's "start" and "limit" member.
+  BaseIndex matchPairStart(FramePointer, matchIndex, TimesEight,
+                           pairsVectorStartOffset + MatchPair::offsetOfStart());
+  BaseIndex matchPairLimit(FramePointer, matchIndex, TimesEight,
+                           pairsVectorStartOffset + MatchPair::offsetOfLimit());
+
+  Label* depStrFailure = &oolEntry;
+  Label restoreRegExpAndLastIndex;
+
+  Register temp4;
+  if (maybeTemp4 == InvalidReg) {
+    depStrFailure = &restoreRegExpAndLastIndex;
+
+    // We don't have enough registers for a fourth temporary. Reuse |regexp|
+    // as a temporary. We restore its value at |restoreRegExpAndLastIndex|.
+    masm.push(regexp);
+    temp4 = regexp;
+  } else {
+    temp4 = maybeTemp4;
+  }
+
+  Register temp5;
+  if (maybeTemp5 == InvalidReg) {
+    depStrFailure = &restoreRegExpAndLastIndex;
+
+    // We don't have enough registers for a fifth temporary. Reuse |lastIndex|
+    // as a temporary. We restore its value at |restoreRegExpAndLastIndex|.
+    masm.push(lastIndex);
+    temp5 = lastIndex;
+  } else {
+    temp5 = maybeTemp5;
+  }
+
+  auto maybeRestoreRegExpAndLastIndex = [&]() {
+    if (maybeTemp5 == InvalidReg) {
+      masm.pop(lastIndex);
+    }
+    if (maybeTemp4 == InvalidReg) {
+      masm.pop(regexp);
+    }
+  };
+
+  // Loop to construct the match strings. There are two different loops,
+  // depending on whether the input is a Two-Byte or a Latin-1 string.
+  CreateDependentString depStrs[]{
+      {CharEncoding::TwoByte, temp3, temp4, temp5, depStrFailure},
+      {CharEncoding::Latin1, temp3, temp4, temp5, depStrFailure},
+  };
+
+  {
+    Label isLatin1, done;
+    masm.branchLatin1String(input, &isLatin1);
+
+    for (auto& depStr : depStrs) {
+      if (depStr.encoding() == CharEncoding::Latin1) {
+        masm.bind(&isLatin1);
+      }
+
+      Label matchLoop;
+      masm.bind(&matchLoop);
+
+      static_assert(MatchPair::NoMatch == -1,
+                    "MatchPair::start is negative if no match was found");
+
+      Label isUndefined, storeDone;
+      masm.branch32(Assembler::LessThan, matchPairStart, Imm32(0),
+                    &isUndefined);
+      {
+        depStr.generate(masm, cx->names(), CompileRuntime::get(cx->runtime()),
+                        input, matchPairStart, matchPairLimit,
+                        initialStringHeap);
+
+        // Storing into nursery-allocated results object's elements; no post
+        // barrier.
+        masm.storeValue(JSVAL_TYPE_STRING, depStr.string(), objectMatchElement);
+        masm.jump(&storeDone);
+      }
+      masm.bind(&isUndefined);
+      { masm.storeValue(UndefinedValue(), objectMatchElement); }
+      masm.bind(&storeDone);
+
+      masm.add32(Imm32(1), matchIndex);
+      masm.branch32(Assembler::LessThanOrEqual, pairCountAddress, matchIndex,
+                    &done);
+      masm.jump(&matchLoop);
+    }
+
+#ifdef DEBUG
+    masm.assumeUnreachable("The match string loop doesn't fall through.");
+#endif
+
+    masm.bind(&done);
+  }
+
+  maybeRestoreRegExpAndLastIndex();
+
+  // Fill in the rest of the output object.
+  masm.store32(
+      matchIndex,
+      Address(object,
+              elementsOffset + ObjectElements::offsetOfInitializedLength()));
+  masm.store32(
+      matchIndex,
+      Address(object, elementsOffset + ObjectElements::offsetOfLength()));
+
+  Address firstMatchPairStartAddress(
+      FramePointer, pairsVectorStartOffset + MatchPair::offsetOfStart());
+  Address firstMatchPairLimitAddress(
+      FramePointer, pairsVectorStartOffset + MatchPair::offsetOfLimit());
+
+  masm.loadPtr(Address(object, NativeObject::offsetOfSlots()), temp2);
+
+  masm.load32(firstMatchPairStartAddress, temp3);
+  masm.storeValue(JSVAL_TYPE_INT32, temp3, Address(temp2, 0));
+
+  // No post barrier needed (address is within nursery object.)
+  masm.storeValue(JSVAL_TYPE_STRING, input, Address(temp2, sizeof(Value)));
+
+  // For the ExecMatch stub, if the regular expression is global or sticky, we
+  // have to update its .lastIndex slot.
+  if (isExecMatch) {
+    MOZ_ASSERT(object != lastIndex);
+    Label notGlobalOrSticky;
+    masm.branchTest32(Assembler::Zero, flagsSlot,
+                      Imm32(JS::RegExpFlag::Global | JS::RegExpFlag::Sticky),
+                      &notGlobalOrSticky);
+    masm.load32(firstMatchPairLimitAddress, lastIndex);
+    masm.storeValue(JSVAL_TYPE_INT32, lastIndex, lastIndexSlot);
+    masm.bind(&notGlobalOrSticky);
+  }
+
+  // All done!
+  masm.tagValue(JSVAL_TYPE_OBJECT, object, result);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  masm.bind(&notFound);
+  if (isExecMatch) {
+    Label notGlobalOrSticky;
+    masm.branchTest32(Assembler::Zero, flagsSlot,
+                      Imm32(JS::RegExpFlag::Global | JS::RegExpFlag::Sticky),
+                      &notGlobalOrSticky);
+    masm.bind(&notFoundZeroLastIndex);
+    masm.storeValue(Int32Value(0), lastIndexSlot);
+    masm.bind(&notGlobalOrSticky);
+  }
+  masm.moveValue(NullValue(), result);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  // Fallback paths for CreateDependentString.
+  for (auto& depStr : depStrs) {
+    depStr.generateFallback(masm);
+  }
+
+  // Fallback path for createGCObject.
+  masm.bind(&matchResultFallback);
+  CreateMatchResultFallback(masm, object, temp2, temp3, templateObj, &oolEntry);
+  masm.jump(&matchResultJoin);
+
+  // Fall-through to the ool entry after restoring the registers.
+  masm.bind(&restoreRegExpAndLastIndex);
+  maybeRestoreRegExpAndLastIndex();
+
+  // Use an undefined value to signal to the caller that the OOL stub needs to
+  // be called.
+  masm.bind(&oolEntry);
+  masm.moveValue(UndefinedValue(), result);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  Linker linker(masm);
+  JitCode* code = linker.newCode(cx, CodeKind::Other);
+  if (!code) {
+    return nullptr;
+  }
+
+  const char* name = isExecMatch ? "RegExpExecMatchStub" : "RegExpMatcherStub";
+  CollectPerfSpewerJitCodeProfile(code, name);
+#ifdef MOZ_VTUNE
+  vtune::MarkStub(code, name);
+#endif
+
+  return code;
+}
+
+JitCode* JitRealm::generateRegExpMatcherStub(JSContext* cx) {
+  return GenerateRegExpMatchStubShared(cx, /* isExecMatch = */ false);
+}
+
+JitCode* JitRealm::generateRegExpExecMatchStub(JSContext* cx) {
+  return GenerateRegExpMatchStubShared(cx, /* isExecMatch = */ true);
+}
+
+class OutOfLineRegExpMatcher : public OutOfLineCodeBase<CodeGenerator> {
+  LRegExpMatcher* lir_;
+
+ public:
+  explicit OutOfLineRegExpMatcher(LRegExpMatcher* lir) : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineRegExpMatcher(this);
+  }
+
+  LRegExpMatcher* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitOutOfLineRegExpMatcher(OutOfLineRegExpMatcher* ool) {
+  LRegExpMatcher* lir = ool->lir();
+  Register lastIndex = ToRegister(lir->lastIndex());
+  Register input = ToRegister(lir->string());
+  Register regexp = ToRegister(lir->regexp());
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+  regs.take(lastIndex);
+  regs.take(input);
+  regs.take(regexp);
+  Register temp = regs.takeAny();
+
+  masm.computeEffectiveAddress(
+      Address(masm.getStackPointer(), InputOutputDataSize), temp);
+
+  pushArg(temp);
+  pushArg(lastIndex);
+  pushArg(input);
+  pushArg(regexp);
+
+  // We are not using oolCallVM because we are in a Call, and that live
+  // registers are already saved by the the register allocator.
+  using Fn =
+      bool (*)(JSContext*, HandleObject regexp, HandleString input,
+               int32_t lastIndex, MatchPairs* pairs, MutableHandleValue output);
+  callVM<Fn, RegExpMatcherRaw>(lir);
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitRegExpMatcher(LRegExpMatcher* lir) {
+  MOZ_ASSERT(ToRegister(lir->regexp()) == RegExpMatcherRegExpReg);
+  MOZ_ASSERT(ToRegister(lir->string()) == RegExpMatcherStringReg);
+  MOZ_ASSERT(ToRegister(lir->lastIndex()) == RegExpMatcherLastIndexReg);
+  MOZ_ASSERT(ToOutValue(lir) == JSReturnOperand);
+
+#if defined(JS_NUNBOX32)
+  static_assert(RegExpMatcherRegExpReg != JSReturnReg_Type);
+  static_assert(RegExpMatcherRegExpReg != JSReturnReg_Data);
+  static_assert(RegExpMatcherStringReg != JSReturnReg_Type);
+  static_assert(RegExpMatcherStringReg != JSReturnReg_Data);
+  static_assert(RegExpMatcherLastIndexReg != JSReturnReg_Type);
+  static_assert(RegExpMatcherLastIndexReg != JSReturnReg_Data);
+#elif defined(JS_PUNBOX64)
+  static_assert(RegExpMatcherRegExpReg != JSReturnReg);
+  static_assert(RegExpMatcherStringReg != JSReturnReg);
+  static_assert(RegExpMatcherLastIndexReg != JSReturnReg);
+#endif
+
+  masm.reserveStack(RegExpReservedStack);
+
+  OutOfLineRegExpMatcher* ool = new (alloc()) OutOfLineRegExpMatcher(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  const JitRealm* jitRealm = gen->realm->jitRealm();
+  JitCode* regExpMatcherStub =
+      jitRealm->regExpMatcherStubNoBarrier(&realmStubsToReadBarrier_);
+  masm.call(regExpMatcherStub);
+  masm.branchTestUndefined(Assembler::Equal, JSReturnOperand, ool->entry());
+  masm.bind(ool->rejoin());
+
+  masm.freeStack(RegExpReservedStack);
+}
+
+class OutOfLineRegExpExecMatch : public OutOfLineCodeBase<CodeGenerator> {
+  LRegExpExecMatch* lir_;
+
+ public:
+  explicit OutOfLineRegExpExecMatch(LRegExpExecMatch* lir) : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineRegExpExecMatch(this);
+  }
+
+  LRegExpExecMatch* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitOutOfLineRegExpExecMatch(
+    OutOfLineRegExpExecMatch* ool) {
+  LRegExpExecMatch* lir = ool->lir();
+  Register input = ToRegister(lir->string());
+  Register regexp = ToRegister(lir->regexp());
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+  regs.take(input);
+  regs.take(regexp);
+  Register temp = regs.takeAny();
+
+  masm.computeEffectiveAddress(
+      Address(masm.getStackPointer(), InputOutputDataSize), temp);
+
+  pushArg(temp);
+  pushArg(input);
+  pushArg(regexp);
+
+  // We are not using oolCallVM because we are in a Call and live registers have
+  // already been saved by the register allocator.
+  using Fn =
+      bool (*)(JSContext*, Handle<RegExpObject*> regexp, HandleString input,
+               MatchPairs* pairs, MutableHandleValue output);
+  callVM<Fn, RegExpBuiltinExecMatchFromJit>(lir);
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitRegExpExecMatch(LRegExpExecMatch* lir) {
+  MOZ_ASSERT(ToRegister(lir->regexp()) == RegExpMatcherRegExpReg);
+  MOZ_ASSERT(ToRegister(lir->string()) == RegExpMatcherStringReg);
+  MOZ_ASSERT(ToOutValue(lir) == JSReturnOperand);
+
+#if defined(JS_NUNBOX32)
+  static_assert(RegExpMatcherRegExpReg != JSReturnReg_Type);
+  static_assert(RegExpMatcherRegExpReg != JSReturnReg_Data);
+  static_assert(RegExpMatcherStringReg != JSReturnReg_Type);
+  static_assert(RegExpMatcherStringReg != JSReturnReg_Data);
+#elif defined(JS_PUNBOX64)
+  static_assert(RegExpMatcherRegExpReg != JSReturnReg);
+  static_assert(RegExpMatcherStringReg != JSReturnReg);
+#endif
+
+  masm.reserveStack(RegExpReservedStack);
+
+  auto* ool = new (alloc()) OutOfLineRegExpExecMatch(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  const JitRealm* jitRealm = gen->realm->jitRealm();
+  JitCode* regExpExecMatchStub =
+      jitRealm->regExpExecMatchStubNoBarrier(&realmStubsToReadBarrier_);
+  masm.call(regExpExecMatchStub);
+  masm.branchTestUndefined(Assembler::Equal, JSReturnOperand, ool->entry());
+
+  masm.bind(ool->rejoin());
+  masm.freeStack(RegExpReservedStack);
+}
+
+JitCode* JitRealm::generateRegExpSearcherStub(JSContext* cx) {
+  JitSpew(JitSpew_Codegen, "# Emitting RegExpSearcher stub");
+
+  Register regexp = RegExpSearcherRegExpReg;
+  Register input = RegExpSearcherStringReg;
+  Register lastIndex = RegExpSearcherLastIndexReg;
+  Register result = ReturnReg;
+
+  // We are free to clobber all registers, as LRegExpSearcher is a call
+  // instruction.
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+  regs.take(input);
+  regs.take(regexp);
+  regs.take(lastIndex);
+
+  Register temp1 = regs.takeAny();
+  Register temp2 = regs.takeAny();
+  Register temp3 = regs.takeAny();
+
+  TempAllocator temp(&cx->tempLifoAlloc());
+  JitContext jcx(cx);
+  StackMacroAssembler masm(cx, temp);
+  AutoCreatedBy acb(masm, "JitRealm::generateRegExpSearcherStub");
+
+#ifdef JS_USE_LINK_REGISTER
+  masm.pushReturnAddress();
+#endif
+  masm.push(FramePointer);
+  masm.moveStackPtrTo(FramePointer);
+
+  // The InputOutputData is placed above the frame pointer and return address on
+  // the stack.
+  int32_t inputOutputDataStartOffset = 2 * sizeof(void*);
+
+  Label notFound, oolEntry;
+  if (!PrepareAndExecuteRegExp(cx, masm, regexp, input, lastIndex, temp1, temp2,
+                               temp3, inputOutputDataStartOffset,
+                               initialStringHeap, &notFound, &oolEntry)) {
+    return nullptr;
+  }
+
+  // clang-format off
+    /*
+     * [SMDOC] Stack layout for the RegExpSearcher stub
+     *
+     *                                    +---------------+
+     *               FramePointer +-----> |Caller-FramePtr|
+     *                                    +---------------+
+     *                                    |Return-Address |
+     *                                    +---------------+
+     * inputOutputDataStartOffset +-----> +---------------+
+     *                                    |InputOutputData|
+     *                                    +---------------+
+     *                                    +---------------+
+     *                                    |  MatchPairs   |
+     *                                    |       count   |
+     *                                    |       pairs   |
+     *                                    |               |
+     *                                    +---------------+
+     *     pairsVectorStartOffset +-----> +---------------+
+     *                                    |   MatchPair   |
+     *             matchPairStart +------------>  start   |  <-------+
+     *             matchPairLimit +------------>  limit   |          | Reserved space for
+     *                                    +---------------+          | `RegExpObject::MaxPairCount`
+     *                                           .                   | MatchPair objects.
+     *                                           .                   |
+     *                                           .                   | Only a single object will
+     *                                    +---------------+          | be initialized and can be
+     *                                    |   MatchPair   |          | accessed below.
+     *                                    |       start   |  <-------+
+     *                                    |       limit   |
+     *                                    +---------------+
+     */
+  // clang-format on
+
+  int32_t pairsVectorStartOffset =
+      RegExpPairsVectorStartOffset(inputOutputDataStartOffset);
+  Address matchPairStart(FramePointer,
+                         pairsVectorStartOffset + MatchPair::offsetOfStart());
+  Address matchPairLimit(FramePointer,
+                         pairsVectorStartOffset + MatchPair::offsetOfLimit());
+
+  masm.load32(matchPairStart, result);
+  masm.load32(matchPairLimit, input);
+  masm.lshiftPtr(Imm32(15), input);
+  masm.or32(input, result);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  masm.bind(&notFound);
+  masm.move32(Imm32(RegExpSearcherResultNotFound), result);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  masm.bind(&oolEntry);
+  masm.move32(Imm32(RegExpSearcherResultFailed), result);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  Linker linker(masm);
+  JitCode* code = linker.newCode(cx, CodeKind::Other);
+  if (!code) {
+    return nullptr;
+  }
+
+  CollectPerfSpewerJitCodeProfile(code, "RegExpSearcherStub");
+#ifdef MOZ_VTUNE
+  vtune::MarkStub(code, "RegExpSearcherStub");
+#endif
+
+  return code;
+}
+
+class OutOfLineRegExpSearcher : public OutOfLineCodeBase<CodeGenerator> {
+  LRegExpSearcher* lir_;
+
+ public:
+  explicit OutOfLineRegExpSearcher(LRegExpSearcher* lir) : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineRegExpSearcher(this);
+  }
+
+  LRegExpSearcher* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitOutOfLineRegExpSearcher(OutOfLineRegExpSearcher* ool) {
+  LRegExpSearcher* lir = ool->lir();
+  Register lastIndex = ToRegister(lir->lastIndex());
+  Register input = ToRegister(lir->string());
+  Register regexp = ToRegister(lir->regexp());
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+  regs.take(lastIndex);
+  regs.take(input);
+  regs.take(regexp);
+  Register temp = regs.takeAny();
+
+  masm.computeEffectiveAddress(
+      Address(masm.getStackPointer(), InputOutputDataSize), temp);
+
+  pushArg(temp);
+  pushArg(lastIndex);
+  pushArg(input);
+  pushArg(regexp);
+
+  // We are not using oolCallVM because we are in a Call, and that live
+  // registers are already saved by the the register allocator.
+  using Fn = bool (*)(JSContext* cx, HandleObject regexp, HandleString input,
+                      int32_t lastIndex, MatchPairs* pairs, int32_t* result);
+  callVM<Fn, RegExpSearcherRaw>(lir);
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitRegExpSearcher(LRegExpSearcher* lir) {
+  MOZ_ASSERT(ToRegister(lir->regexp()) == RegExpSearcherRegExpReg);
+  MOZ_ASSERT(ToRegister(lir->string()) == RegExpSearcherStringReg);
+  MOZ_ASSERT(ToRegister(lir->lastIndex()) == RegExpSearcherLastIndexReg);
+  MOZ_ASSERT(ToRegister(lir->output()) == ReturnReg);
+
+  static_assert(RegExpSearcherRegExpReg != ReturnReg);
+  static_assert(RegExpSearcherStringReg != ReturnReg);
+  static_assert(RegExpSearcherLastIndexReg != ReturnReg);
+
+  masm.reserveStack(RegExpReservedStack);
+
+  OutOfLineRegExpSearcher* ool = new (alloc()) OutOfLineRegExpSearcher(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  const JitRealm* jitRealm = gen->realm->jitRealm();
+  JitCode* regExpSearcherStub =
+      jitRealm->regExpSearcherStubNoBarrier(&realmStubsToReadBarrier_);
+  masm.call(regExpSearcherStub);
+  masm.branch32(Assembler::Equal, ReturnReg, Imm32(RegExpSearcherResultFailed),
+                ool->entry());
+  masm.bind(ool->rejoin());
+
+  masm.freeStack(RegExpReservedStack);
+}
+
+JitCode* JitRealm::generateRegExpExecTestStub(JSContext* cx) {
+  JitSpew(JitSpew_Codegen, "# Emitting RegExpExecTest stub");
+
+  Register regexp = RegExpExecTestRegExpReg;
+  Register input = RegExpExecTestStringReg;
+  Register result = ReturnReg;
+
+  TempAllocator temp(&cx->tempLifoAlloc());
+  JitContext jcx(cx);
+  StackMacroAssembler masm(cx, temp);
+  AutoCreatedBy acb(masm, "JitRealm::generateRegExpExecTestStub");
+
+#ifdef JS_USE_LINK_REGISTER
+  masm.pushReturnAddress();
+#endif
+  masm.push(FramePointer);
+  masm.moveStackPtrTo(FramePointer);
+
+  // We are free to clobber all registers, as LRegExpExecTest is a call
+  // instruction.
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+  regs.take(input);
+  regs.take(regexp);
+
+  // Ensure lastIndex != result.
+  regs.take(result);
+  Register lastIndex = regs.takeAny();
+  regs.add(result);
+  Register temp1 = regs.takeAny();
+  Register temp2 = regs.takeAny();
+  Register temp3 = regs.takeAny();
+
+  Address flagsSlot(regexp, RegExpObject::offsetOfFlags());
+  Address lastIndexSlot(regexp, RegExpObject::offsetOfLastIndex());
+
+  masm.reserveStack(RegExpReservedStack);
+
+  // Load lastIndex and skip RegExp execution if needed.
+  Label notFoundZeroLastIndex;
+  masm.loadRegExpLastIndex(regexp, input, lastIndex, &notFoundZeroLastIndex);
+
+  // In visitRegExpMatcher and visitRegExpSearcher, we reserve stack space
+  // before calling the stub. For RegExpExecTest we call the stub before
+  // reserving stack space, so the offset of the InputOutputData relative to the
+  // frame pointer is negative.
+  constexpr int32_t inputOutputDataStartOffset = -int32_t(RegExpReservedStack);
+
+  // On ARM64, load/store instructions can encode an immediate offset in the
+  // range [-256, 4095]. If we ever fail this assertion, it would be more
+  // efficient to store the data above the frame pointer similar to
+  // RegExpMatcher and RegExpSearcher.
+  static_assert(inputOutputDataStartOffset >= -256);
+
+  Label notFound, oolEntry;
+  if (!PrepareAndExecuteRegExp(cx, masm, regexp, input, lastIndex, temp1, temp2,
+                               temp3, inputOutputDataStartOffset,
+                               initialStringHeap, &notFound, &oolEntry)) {
+    return nullptr;
+  }
+
+  // Set `result` to true/false to indicate found/not-found, or to
+  // RegExpExecTestResultFailed if we have to retry in C++. If the regular
+  // expression is global or sticky, we also have to update its .lastIndex slot.
+
+  Label done;
+  int32_t pairsVectorStartOffset =
+      RegExpPairsVectorStartOffset(inputOutputDataStartOffset);
+  Address matchPairLimit(FramePointer,
+                         pairsVectorStartOffset + MatchPair::offsetOfLimit());
+
+  masm.move32(Imm32(1), result);
+  masm.branchTest32(Assembler::Zero, flagsSlot,
+                    Imm32(JS::RegExpFlag::Global | JS::RegExpFlag::Sticky),
+                    &done);
+  masm.load32(matchPairLimit, lastIndex);
+  masm.storeValue(JSVAL_TYPE_INT32, lastIndex, lastIndexSlot);
+  masm.jump(&done);
+
+  masm.bind(&notFound);
+  masm.move32(Imm32(0), result);
+  masm.branchTest32(Assembler::Zero, flagsSlot,
+                    Imm32(JS::RegExpFlag::Global | JS::RegExpFlag::Sticky),
+                    &done);
+  masm.storeValue(Int32Value(0), lastIndexSlot);
+  masm.jump(&done);
+
+  masm.bind(&notFoundZeroLastIndex);
+  masm.move32(Imm32(0), result);
+  masm.storeValue(Int32Value(0), lastIndexSlot);
+  masm.jump(&done);
+
+  masm.bind(&oolEntry);
+  masm.move32(Imm32(RegExpExecTestResultFailed), result);
+
+  masm.bind(&done);
+  masm.freeStack(RegExpReservedStack);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  Linker linker(masm);
+  JitCode* code = linker.newCode(cx, CodeKind::Other);
+  if (!code) {
+    return nullptr;
+  }
+
+  CollectPerfSpewerJitCodeProfile(code, "RegExpExecTestStub");
+#ifdef MOZ_VTUNE
+  vtune::MarkStub(code, "RegExpExecTestStub");
+#endif
+
+  return code;
+}
+
+class OutOfLineRegExpExecTest : public OutOfLineCodeBase<CodeGenerator> {
+  LRegExpExecTest* lir_;
+
+ public:
+  explicit OutOfLineRegExpExecTest(LRegExpExecTest* lir) : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineRegExpExecTest(this);
+  }
+
+  LRegExpExecTest* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitOutOfLineRegExpExecTest(OutOfLineRegExpExecTest* ool) {
+  LRegExpExecTest* lir = ool->lir();
+  Register input = ToRegister(lir->string());
+  Register regexp = ToRegister(lir->regexp());
+
+  pushArg(input);
+  pushArg(regexp);
+
+  // We are not using oolCallVM because we are in a Call and live registers have
+  // already been saved by the register allocator.
+  using Fn = bool (*)(JSContext* cx, Handle<RegExpObject*> regexp,
+                      HandleString input, bool* result);
+  callVM<Fn, RegExpBuiltinExecTestFromJit>(lir);
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitRegExpExecTest(LRegExpExecTest* lir) {
+  MOZ_ASSERT(ToRegister(lir->regexp()) == RegExpExecTestRegExpReg);
+  MOZ_ASSERT(ToRegister(lir->string()) == RegExpExecTestStringReg);
+  MOZ_ASSERT(ToRegister(lir->output()) == ReturnReg);
+
+  static_assert(RegExpExecTestRegExpReg != ReturnReg);
+  static_assert(RegExpExecTestStringReg != ReturnReg);
+
+  auto* ool = new (alloc()) OutOfLineRegExpExecTest(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  const JitRealm* jitRealm = gen->realm->jitRealm();
+  JitCode* regExpExecTestStub =
+      jitRealm->regExpExecTestStubNoBarrier(&realmStubsToReadBarrier_);
+  masm.call(regExpExecTestStub);
+
+  masm.branch32(Assembler::Equal, ReturnReg, Imm32(RegExpExecTestResultFailed),
+                ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+class OutOfLineRegExpPrototypeOptimizable
+    : public OutOfLineCodeBase<CodeGenerator> {
+  LRegExpPrototypeOptimizable* ins_;
+
+ public:
+  explicit OutOfLineRegExpPrototypeOptimizable(LRegExpPrototypeOptimizable* ins)
+      : ins_(ins) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineRegExpPrototypeOptimizable(this);
+  }
+  LRegExpPrototypeOptimizable* ins() const { return ins_; }
+};
+
+void CodeGenerator::visitRegExpPrototypeOptimizable(
+    LRegExpPrototypeOptimizable* ins) {
+  Register object = ToRegister(ins->object());
+  Register output = ToRegister(ins->output());
+  Register temp = ToRegister(ins->temp0());
+
+  OutOfLineRegExpPrototypeOptimizable* ool =
+      new (alloc()) OutOfLineRegExpPrototypeOptimizable(ins);
+  addOutOfLineCode(ool, ins->mir());
+
+  masm.branchIfNotRegExpPrototypeOptimizable(object, temp, ool->entry());
+  masm.move32(Imm32(0x1), output);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineRegExpPrototypeOptimizable(
+    OutOfLineRegExpPrototypeOptimizable* ool) {
+  LRegExpPrototypeOptimizable* ins = ool->ins();
+  Register object = ToRegister(ins->object());
+  Register output = ToRegister(ins->output());
+
+  saveVolatile(output);
+
+  using Fn = bool (*)(JSContext* cx, JSObject* proto);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(output);
+  masm.passABIArg(output);
+  masm.passABIArg(object);
+  masm.callWithABI<Fn, RegExpPrototypeOptimizableRaw>();
+  masm.storeCallBoolResult(output);
+
+  restoreVolatile(output);
+
+  masm.jump(ool->rejoin());
+}
+
+class OutOfLineRegExpInstanceOptimizable
+    : public OutOfLineCodeBase<CodeGenerator> {
+  LRegExpInstanceOptimizable* ins_;
+
+ public:
+  explicit OutOfLineRegExpInstanceOptimizable(LRegExpInstanceOptimizable* ins)
+      : ins_(ins) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineRegExpInstanceOptimizable(this);
+  }
+  LRegExpInstanceOptimizable* ins() const { return ins_; }
+};
+
+void CodeGenerator::visitRegExpInstanceOptimizable(
+    LRegExpInstanceOptimizable* ins) {
+  Register object = ToRegister(ins->object());
+  Register output = ToRegister(ins->output());
+  Register temp = ToRegister(ins->temp0());
+
+  OutOfLineRegExpInstanceOptimizable* ool =
+      new (alloc()) OutOfLineRegExpInstanceOptimizable(ins);
+  addOutOfLineCode(ool, ins->mir());
+
+  masm.branchIfNotRegExpInstanceOptimizable(object, temp, ool->entry());
+  masm.move32(Imm32(0x1), output);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineRegExpInstanceOptimizable(
+    OutOfLineRegExpInstanceOptimizable* ool) {
+  LRegExpInstanceOptimizable* ins = ool->ins();
+  Register object = ToRegister(ins->object());
+  Register proto = ToRegister(ins->proto());
+  Register output = ToRegister(ins->output());
+
+  saveVolatile(output);
+
+  using Fn = bool (*)(JSContext* cx, JSObject* obj, JSObject* proto);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(output);
+  masm.passABIArg(output);
+  masm.passABIArg(object);
+  masm.passABIArg(proto);
+  masm.callWithABI<Fn, RegExpInstanceOptimizableRaw>();
+  masm.storeCallBoolResult(output);
+
+  restoreVolatile(output);
+
+  masm.jump(ool->rejoin());
+}
+
+static void FindFirstDollarIndex(MacroAssembler& masm, Register str,
+                                 Register len, Register temp0, Register temp1,
+                                 Register output, CharEncoding encoding) {
+#ifdef DEBUG
+  Label ok;
+  masm.branch32(Assembler::GreaterThan, len, Imm32(0), &ok);
+  masm.assumeUnreachable("Length should be greater than 0.");
+  masm.bind(&ok);
+#endif
+
+  Register chars = temp0;
+  masm.loadStringChars(str, chars, encoding);
+
+  masm.move32(Imm32(0), output);
+
+  Label start, done;
+  masm.bind(&start);
+
+  Register currentChar = temp1;
+  masm.loadChar(chars, output, currentChar, encoding);
+  masm.branch32(Assembler::Equal, currentChar, Imm32('$'), &done);
+
+  masm.add32(Imm32(1), output);
+  masm.branch32(Assembler::NotEqual, output, len, &start);
+
+  masm.move32(Imm32(-1), output);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGetFirstDollarIndex(LGetFirstDollarIndex* ins) {
+  Register str = ToRegister(ins->str());
+  Register output = ToRegister(ins->output());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register len = ToRegister(ins->temp2());
+
+  using Fn = bool (*)(JSContext*, JSString*, int32_t*);
+  OutOfLineCode* ool = oolCallVM<Fn, GetFirstDollarIndexRaw>(
+      ins, ArgList(str), StoreRegisterTo(output));
+
+  masm.branchIfRope(str, ool->entry());
+  masm.loadStringLength(str, len);
+
+  Label isLatin1, done;
+  masm.branchLatin1String(str, &isLatin1);
+  {
+    FindFirstDollarIndex(masm, str, len, temp0, temp1, output,
+                         CharEncoding::TwoByte);
+    masm.jump(&done);
+  }
+  masm.bind(&isLatin1);
+  {
+    FindFirstDollarIndex(masm, str, len, temp0, temp1, output,
+                         CharEncoding::Latin1);
+  }
+  masm.bind(&done);
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitStringReplace(LStringReplace* lir) {
+  if (lir->replacement()->isConstant()) {
+    pushArg(ImmGCPtr(lir->replacement()->toConstant()->toString()));
+  } else {
+    pushArg(ToRegister(lir->replacement()));
+  }
+
+  if (lir->pattern()->isConstant()) {
+    pushArg(ImmGCPtr(lir->pattern()->toConstant()->toString()));
+  } else {
+    pushArg(ToRegister(lir->pattern()));
+  }
+
+  if (lir->string()->isConstant()) {
+    pushArg(ImmGCPtr(lir->string()->toConstant()->toString()));
+  } else {
+    pushArg(ToRegister(lir->string()));
+  }
+
+  using Fn =
+      JSString* (*)(JSContext*, HandleString, HandleString, HandleString);
+  if (lir->mir()->isFlatReplacement()) {
+    callVM<Fn, StringFlatReplaceString>(lir);
+  } else {
+    callVM<Fn, StringReplace>(lir);
+  }
+}
+
+void CodeGenerator::visitBinaryValueCache(LBinaryValueCache* lir) {
+  LiveRegisterSet liveRegs = lir->safepoint()->liveRegs();
+  TypedOrValueRegister lhs =
+      TypedOrValueRegister(ToValue(lir, LBinaryValueCache::LhsIndex));
+  TypedOrValueRegister rhs =
+      TypedOrValueRegister(ToValue(lir, LBinaryValueCache::RhsIndex));
+  ValueOperand output = ToOutValue(lir);
+
+  JSOp jsop = JSOp(*lir->mirRaw()->toInstruction()->resumePoint()->pc());
+
+  switch (jsop) {
+    case JSOp::Add:
+    case JSOp::Sub:
+    case JSOp::Mul:
+    case JSOp::Div:
+    case JSOp::Mod:
+    case JSOp::Pow:
+    case JSOp::BitAnd:
+    case JSOp::BitOr:
+    case JSOp::BitXor:
+    case JSOp::Lsh:
+    case JSOp::Rsh:
+    case JSOp::Ursh: {
+      IonBinaryArithIC ic(liveRegs, lhs, rhs, output);
+      addIC(lir, allocateIC(ic));
+      return;
+    }
+    default:
+      MOZ_CRASH("Unsupported jsop in MBinaryValueCache");
+  }
+}
+
+void CodeGenerator::visitBinaryBoolCache(LBinaryBoolCache* lir) {
+  LiveRegisterSet liveRegs = lir->safepoint()->liveRegs();
+  TypedOrValueRegister lhs =
+      TypedOrValueRegister(ToValue(lir, LBinaryBoolCache::LhsIndex));
+  TypedOrValueRegister rhs =
+      TypedOrValueRegister(ToValue(lir, LBinaryBoolCache::RhsIndex));
+  Register output = ToRegister(lir->output());
+
+  JSOp jsop = JSOp(*lir->mirRaw()->toInstruction()->resumePoint()->pc());
+
+  switch (jsop) {
+    case JSOp::Lt:
+    case JSOp::Le:
+    case JSOp::Gt:
+    case JSOp::Ge:
+    case JSOp::Eq:
+    case JSOp::Ne:
+    case JSOp::StrictEq:
+    case JSOp::StrictNe: {
+      IonCompareIC ic(liveRegs, lhs, rhs, output);
+      addIC(lir, allocateIC(ic));
+      return;
+    }
+    default:
+      MOZ_CRASH("Unsupported jsop in MBinaryBoolCache");
+  }
+}
+
+void CodeGenerator::visitUnaryCache(LUnaryCache* lir) {
+  LiveRegisterSet liveRegs = lir->safepoint()->liveRegs();
+  TypedOrValueRegister input =
+      TypedOrValueRegister(ToValue(lir, LUnaryCache::InputIndex));
+  ValueOperand output = ToOutValue(lir);
+
+  IonUnaryArithIC ic(liveRegs, input, output);
+  addIC(lir, allocateIC(ic));
+}
+
+void CodeGenerator::visitModuleMetadata(LModuleMetadata* lir) {
+  pushArg(ImmPtr(lir->mir()->module()));
+
+  using Fn = JSObject* (*)(JSContext*, HandleObject);
+  callVM<Fn, js::GetOrCreateModuleMetaObject>(lir);
+}
+
+void CodeGenerator::visitDynamicImport(LDynamicImport* lir) {
+  pushArg(ToValue(lir, LDynamicImport::OptionsIndex));
+  pushArg(ToValue(lir, LDynamicImport::SpecifierIndex));
+  pushArg(ImmGCPtr(current->mir()->info().script()));
+
+  using Fn = JSObject* (*)(JSContext*, HandleScript, HandleValue, HandleValue);
+  callVM<Fn, js::StartDynamicModuleImport>(lir);
+}
+
+void CodeGenerator::visitLambda(LLambda* lir) {
+  Register envChain = ToRegister(lir->environmentChain());
+  Register output = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp0());
+
+  JSFunction* fun = lir->mir()->templateFunction();
+
+  using Fn = JSObject* (*)(JSContext*, HandleFunction, HandleObject);
+  OutOfLineCode* ool = oolCallVM<Fn, js::Lambda>(
+      lir, ArgList(ImmGCPtr(fun), envChain), StoreRegisterTo(output));
+
+  TemplateObject templateObject(fun);
+  masm.createGCObject(output, tempReg, templateObject, gc::Heap::Default,
+                      ool->entry());
+
+  masm.storeValue(JSVAL_TYPE_OBJECT, envChain,
+                  Address(output, JSFunction::offsetOfEnvironment()));
+  // No post barrier needed because output is guaranteed to be allocated in
+  // the nursery.
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitFunctionWithProto(LFunctionWithProto* lir) {
+  Register envChain = ToRegister(lir->envChain());
+  Register prototype = ToRegister(lir->prototype());
+
+  pushArg(prototype);
+  pushArg(envChain);
+  pushArg(ImmGCPtr(lir->mir()->function()));
+
+  using Fn =
+      JSObject* (*)(JSContext*, HandleFunction, HandleObject, HandleObject);
+  callVM<Fn, js::FunWithProtoOperation>(lir);
+}
+
+void CodeGenerator::visitSetFunName(LSetFunName* lir) {
+  pushArg(Imm32(lir->mir()->prefixKind()));
+  pushArg(ToValue(lir, LSetFunName::NameIndex));
+  pushArg(ToRegister(lir->fun()));
+
+  using Fn =
+      bool (*)(JSContext*, HandleFunction, HandleValue, FunctionPrefixKind);
+  callVM<Fn, js::SetFunctionName>(lir);
+}
+
+void CodeGenerator::visitOsiPoint(LOsiPoint* lir) {
+  // Note: markOsiPoint ensures enough space exists between the last
+  // LOsiPoint and this one to patch adjacent call instructions.
+
+  MOZ_ASSERT(masm.framePushed() == frameSize());
+
+  uint32_t osiCallPointOffset = markOsiPoint(lir);
+
+  LSafepoint* safepoint = lir->associatedSafepoint();
+  MOZ_ASSERT(!safepoint->osiCallPointOffset());
+  safepoint->setOsiCallPointOffset(osiCallPointOffset);
+
+#ifdef DEBUG
+  // There should be no movegroups or other instructions between
+  // an instruction and its OsiPoint. This is necessary because
+  // we use the OsiPoint's snapshot from within VM calls.
+  for (LInstructionReverseIterator iter(current->rbegin(lir));
+       iter != current->rend(); iter++) {
+    if (*iter == lir) {
+      continue;
+    }
+    MOZ_ASSERT(!iter->isMoveGroup());
+    MOZ_ASSERT(iter->safepoint() == safepoint);
+    break;
+  }
+#endif
+
+#ifdef CHECK_OSIPOINT_REGISTERS
+  if (shouldVerifyOsiPointRegs(safepoint)) {
+    verifyOsiPointRegs(safepoint);
+  }
+#endif
+}
+
+void CodeGenerator::visitPhi(LPhi* lir) {
+  MOZ_CRASH("Unexpected LPhi in CodeGenerator");
+}
+
+void CodeGenerator::visitGoto(LGoto* lir) { jumpToBlock(lir->target()); }
+
+void CodeGenerator::visitTableSwitch(LTableSwitch* ins) {
+  MTableSwitch* mir = ins->mir();
+  Label* defaultcase = skipTrivialBlocks(mir->getDefault())->lir()->label();
+  const LAllocation* temp;
+
+  if (mir->getOperand(0)->type() != MIRType::Int32) {
+    temp = ins->tempInt()->output();
+
+    // The input is a double, so try and convert it to an integer.
+    // If it does not fit in an integer, take the default case.
+    masm.convertDoubleToInt32(ToFloatRegister(ins->index()), ToRegister(temp),
+                              defaultcase, false);
+  } else {
+    temp = ins->index();
+  }
+
+  emitTableSwitchDispatch(mir, ToRegister(temp),
+                          ToRegisterOrInvalid(ins->tempPointer()));
+}
+
+void CodeGenerator::visitTableSwitchV(LTableSwitchV* ins) {
+  MTableSwitch* mir = ins->mir();
+  Label* defaultcase = skipTrivialBlocks(mir->getDefault())->lir()->label();
+
+  Register index = ToRegister(ins->tempInt());
+  ValueOperand value = ToValue(ins, LTableSwitchV::InputValue);
+  Register tag = masm.extractTag(value, index);
+  masm.branchTestNumber(Assembler::NotEqual, tag, defaultcase);
+
+  Label unboxInt, isInt;
+  masm.branchTestInt32(Assembler::Equal, tag, &unboxInt);
+  {
+    FloatRegister floatIndex = ToFloatRegister(ins->tempFloat());
+    masm.unboxDouble(value, floatIndex);
+    masm.convertDoubleToInt32(floatIndex, index, defaultcase, false);
+    masm.jump(&isInt);
+  }
+
+  masm.bind(&unboxInt);
+  masm.unboxInt32(value, index);
+
+  masm.bind(&isInt);
+
+  emitTableSwitchDispatch(mir, index, ToRegisterOrInvalid(ins->tempPointer()));
+}
+
+void CodeGenerator::visitParameter(LParameter* lir) {}
+
+void CodeGenerator::visitCallee(LCallee* lir) {
+  Register callee = ToRegister(lir->output());
+  Address ptr(FramePointer, JitFrameLayout::offsetOfCalleeToken());
+
+  masm.loadFunctionFromCalleeToken(ptr, callee);
+}
+
+void CodeGenerator::visitIsConstructing(LIsConstructing* lir) {
+  Register output = ToRegister(lir->output());
+  Address calleeToken(FramePointer, JitFrameLayout::offsetOfCalleeToken());
+  masm.loadPtr(calleeToken, output);
+
+  // We must be inside a function.
+  MOZ_ASSERT(current->mir()->info().script()->function());
+
+  // The low bit indicates whether this call is constructing, just clear the
+  // other bits.
+  static_assert(CalleeToken_Function == 0x0,
+                "CalleeTokenTag value should match");
+  static_assert(CalleeToken_FunctionConstructing == 0x1,
+                "CalleeTokenTag value should match");
+  masm.andPtr(Imm32(0x1), output);
+}
+
+void CodeGenerator::visitReturn(LReturn* lir) {
+#if defined(JS_NUNBOX32)
+  DebugOnly<LAllocation*> type = lir->getOperand(TYPE_INDEX);
+  DebugOnly<LAllocation*> payload = lir->getOperand(PAYLOAD_INDEX);
+  MOZ_ASSERT(ToRegister(type) == JSReturnReg_Type);
+  MOZ_ASSERT(ToRegister(payload) == JSReturnReg_Data);
+#elif defined(JS_PUNBOX64)
+  DebugOnly<LAllocation*> result = lir->getOperand(0);
+  MOZ_ASSERT(ToRegister(result) == JSReturnReg);
+#endif
+  // Don't emit a jump to the return label if this is the last block, as
+  // it'll fall through to the epilogue.
+  //
+  // This is -not- true however for a Generator-return, which may appear in the
+  // middle of the last block, so we should always emit the jump there.
+  if (current->mir() != *gen->graph().poBegin() || lir->isGenerator()) {
+    masm.jump(&returnLabel_);
+  }
+}
+
+void CodeGenerator::visitOsrEntry(LOsrEntry* lir) {
+  Register temp = ToRegister(lir->temp());
+
+  // Remember the OSR entry offset into the code buffer.
+  masm.flushBuffer();
+  setOsrEntryOffset(masm.size());
+
+  // Allocate the full frame for this function
+  // Note we have a new entry here. So we reset MacroAssembler::framePushed()
+  // to 0, before reserving the stack.
+  MOZ_ASSERT(masm.framePushed() == frameSize());
+  masm.setFramePushed(0);
+
+  // The Baseline code ensured both the frame pointer and stack pointer point to
+  // the JitFrameLayout on the stack.
+
+  // If profiling, save the current frame pointer to a per-thread global field.
+  if (isProfilerInstrumentationEnabled()) {
+    masm.profilerEnterFrame(FramePointer, temp);
+  }
+
+  masm.reserveStack(frameSize());
+  MOZ_ASSERT(masm.framePushed() == frameSize());
+
+  // Ensure that the Ion frames is properly aligned.
+  masm.assertStackAlignment(JitStackAlignment, 0);
+}
+
+void CodeGenerator::visitOsrEnvironmentChain(LOsrEnvironmentChain* lir) {
+  const LAllocation* frame = lir->getOperand(0);
+  const LDefinition* object = lir->getDef(0);
+
+  const ptrdiff_t frameOffset =
+      BaselineFrame::reverseOffsetOfEnvironmentChain();
+
+  masm.loadPtr(Address(ToRegister(frame), frameOffset), ToRegister(object));
+}
+
+void CodeGenerator::visitOsrArgumentsObject(LOsrArgumentsObject* lir) {
+  const LAllocation* frame = lir->getOperand(0);
+  const LDefinition* object = lir->getDef(0);
+
+  const ptrdiff_t frameOffset = BaselineFrame::reverseOffsetOfArgsObj();
+
+  masm.loadPtr(Address(ToRegister(frame), frameOffset), ToRegister(object));
+}
+
+void CodeGenerator::visitOsrValue(LOsrValue* value) {
+  const LAllocation* frame = value->getOperand(0);
+  const ValueOperand out = ToOutValue(value);
+
+  const ptrdiff_t frameOffset = value->mir()->frameOffset();
+
+  masm.loadValue(Address(ToRegister(frame), frameOffset), out);
+}
+
+void CodeGenerator::visitOsrReturnValue(LOsrReturnValue* lir) {
+  const LAllocation* frame = lir->getOperand(0);
+  const ValueOperand out = ToOutValue(lir);
+
+  Address flags =
+      Address(ToRegister(frame), BaselineFrame::reverseOffsetOfFlags());
+  Address retval =
+      Address(ToRegister(frame), BaselineFrame::reverseOffsetOfReturnValue());
+
+  masm.moveValue(UndefinedValue(), out);
+
+  Label done;
+  masm.branchTest32(Assembler::Zero, flags, Imm32(BaselineFrame::HAS_RVAL),
+                    &done);
+  masm.loadValue(retval, out);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitStackArgT(LStackArgT* lir) {
+  const LAllocation* arg = lir->arg();
+  MIRType argType = lir->type();
+  uint32_t argslot = lir->argslot();
+  MOZ_ASSERT(argslot - 1u < graph.argumentSlotCount());
+
+  Address dest = AddressOfPassedArg(argslot);
+
+  if (arg->isFloatReg()) {
+    masm.boxDouble(ToFloatRegister(arg), dest);
+  } else if (arg->isRegister()) {
+    masm.storeValue(ValueTypeFromMIRType(argType), ToRegister(arg), dest);
+  } else {
+    masm.storeValue(arg->toConstant()->toJSValue(), dest);
+  }
+}
+
+void CodeGenerator::visitStackArgV(LStackArgV* lir) {
+  ValueOperand val = ToValue(lir, 0);
+  uint32_t argslot = lir->argslot();
+  MOZ_ASSERT(argslot - 1u < graph.argumentSlotCount());
+
+  masm.storeValue(val, AddressOfPassedArg(argslot));
+}
+
+void CodeGenerator::visitMoveGroup(LMoveGroup* group) {
+  if (!group->numMoves()) {
+    return;
+  }
+
+  MoveResolver& resolver = masm.moveResolver();
+
+  for (size_t i = 0; i < group->numMoves(); i++) {
+    const LMove& move = group->getMove(i);
+
+    LAllocation from = move.from();
+    LAllocation to = move.to();
+    LDefinition::Type type = move.type();
+
+    // No bogus moves.
+    MOZ_ASSERT(from != to);
+    MOZ_ASSERT(!from.isConstant());
+    MoveOp::Type moveType;
+    switch (type) {
+      case LDefinition::OBJECT:
+      case LDefinition::SLOTS:
+#ifdef JS_NUNBOX32
+      case LDefinition::TYPE:
+      case LDefinition::PAYLOAD:
+#else
+      case LDefinition::BOX:
+#endif
+      case LDefinition::GENERAL:
+      case LDefinition::STACKRESULTS:
+        moveType = MoveOp::GENERAL;
+        break;
+      case LDefinition::INT32:
+        moveType = MoveOp::INT32;
+        break;
+      case LDefinition::FLOAT32:
+        moveType = MoveOp::FLOAT32;
+        break;
+      case LDefinition::DOUBLE:
+        moveType = MoveOp::DOUBLE;
+        break;
+      case LDefinition::SIMD128:
+        moveType = MoveOp::SIMD128;
+        break;
+      default:
+        MOZ_CRASH("Unexpected move type");
+    }
+
+    masm.propagateOOM(
+        resolver.addMove(toMoveOperand(from), toMoveOperand(to), moveType));
+  }
+
+  masm.propagateOOM(resolver.resolve());
+  if (masm.oom()) {
+    return;
+  }
+
+  MoveEmitter emitter(masm);
+
+#ifdef JS_CODEGEN_X86
+  if (group->maybeScratchRegister().isGeneralReg()) {
+    emitter.setScratchRegister(
+        group->maybeScratchRegister().toGeneralReg()->reg());
+  } else {
+    resolver.sortMemoryToMemoryMoves();
+  }
+#endif
+
+  emitter.emit(resolver);
+  emitter.finish();
+}
+
+void CodeGenerator::visitInteger(LInteger* lir) {
+  masm.move32(Imm32(lir->i32()), ToRegister(lir->output()));
+}
+
+void CodeGenerator::visitInteger64(LInteger64* lir) {
+  masm.move64(Imm64(lir->i64()), ToOutRegister64(lir));
+}
+
+void CodeGenerator::visitPointer(LPointer* lir) {
+  masm.movePtr(ImmGCPtr(lir->gcptr()), ToRegister(lir->output()));
+}
+
+void CodeGenerator::visitNurseryObject(LNurseryObject* lir) {
+  Register output = ToRegister(lir->output());
+  uint32_t nurseryIndex = lir->mir()->nurseryIndex();
+
+  // Load a pointer to the entry in IonScript's nursery objects list.
+  CodeOffset label = masm.movWithPatch(ImmWord(uintptr_t(-1)), output);
+  masm.propagateOOM(ionNurseryObjectLabels_.emplaceBack(label, nurseryIndex));
+
+  // Load the JSObject*.
+  masm.loadPtr(Address(output, 0), output);
+}
+
+void CodeGenerator::visitKeepAliveObject(LKeepAliveObject* lir) {
+  // No-op.
+}
+
+void CodeGenerator::visitDebugEnterGCUnsafeRegion(
+    LDebugEnterGCUnsafeRegion* lir) {
+  Register temp = ToRegister(lir->temp0());
+
+  masm.loadJSContext(temp);
+
+  Address inUnsafeRegion(temp, JSContext::offsetOfInUnsafeRegion());
+  masm.add32(Imm32(1), inUnsafeRegion);
+
+  Label ok;
+  masm.branch32(Assembler::GreaterThan, inUnsafeRegion, Imm32(0), &ok);
+  masm.assumeUnreachable("unbalanced enter/leave GC unsafe region");
+  masm.bind(&ok);
+}
+
+void CodeGenerator::visitDebugLeaveGCUnsafeRegion(
+    LDebugLeaveGCUnsafeRegion* lir) {
+  Register temp = ToRegister(lir->temp0());
+
+  masm.loadJSContext(temp);
+
+  Address inUnsafeRegion(temp, JSContext::offsetOfInUnsafeRegion());
+  masm.add32(Imm32(-1), inUnsafeRegion);
+
+  Label ok;
+  masm.branch32(Assembler::GreaterThanOrEqual, inUnsafeRegion, Imm32(0), &ok);
+  masm.assumeUnreachable("unbalanced enter/leave GC unsafe region");
+  masm.bind(&ok);
+}
+
+void CodeGenerator::visitSlots(LSlots* lir) {
+  Address slots(ToRegister(lir->object()), NativeObject::offsetOfSlots());
+  masm.loadPtr(slots, ToRegister(lir->output()));
+}
+
+void CodeGenerator::visitLoadDynamicSlotV(LLoadDynamicSlotV* lir) {
+  ValueOperand dest = ToOutValue(lir);
+  Register base = ToRegister(lir->input());
+  int32_t offset = lir->mir()->slot() * sizeof(js::Value);
+
+  masm.loadValue(Address(base, offset), dest);
+}
+
+static ConstantOrRegister ToConstantOrRegister(const LAllocation* value,
+                                               MIRType valueType) {
+  if (value->isConstant()) {
+    return ConstantOrRegister(value->toConstant()->toJSValue());
+  }
+  return TypedOrValueRegister(valueType, ToAnyRegister(value));
+}
+
+void CodeGenerator::visitStoreDynamicSlotT(LStoreDynamicSlotT* lir) {
+  Register base = ToRegister(lir->slots());
+  int32_t offset = lir->mir()->slot() * sizeof(js::Value);
+  Address dest(base, offset);
+
+  if (lir->mir()->needsBarrier()) {
+    emitPreBarrier(dest);
+  }
+
+  MIRType valueType = lir->mir()->value()->type();
+  ConstantOrRegister value = ToConstantOrRegister(lir->value(), valueType);
+  masm.storeUnboxedValue(value, valueType, dest);
+}
+
+void CodeGenerator::visitStoreDynamicSlotV(LStoreDynamicSlotV* lir) {
+  Register base = ToRegister(lir->slots());
+  int32_t offset = lir->mir()->slot() * sizeof(Value);
+
+  const ValueOperand value = ToValue(lir, LStoreDynamicSlotV::ValueIndex);
+
+  if (lir->mir()->needsBarrier()) {
+    emitPreBarrier(Address(base, offset));
+  }
+
+  masm.storeValue(value, Address(base, offset));
+}
+
+void CodeGenerator::visitElements(LElements* lir) {
+  Address elements(ToRegister(lir->object()), NativeObject::offsetOfElements());
+  masm.loadPtr(elements, ToRegister(lir->output()));
+}
+
+void CodeGenerator::visitFunctionEnvironment(LFunctionEnvironment* lir) {
+  Address environment(ToRegister(lir->function()),
+                      JSFunction::offsetOfEnvironment());
+  masm.unboxObject(environment, ToRegister(lir->output()));
+}
+
+void CodeGenerator::visitHomeObject(LHomeObject* lir) {
+  Register func = ToRegister(lir->function());
+  Address homeObject(func, FunctionExtended::offsetOfMethodHomeObjectSlot());
+
+  masm.assertFunctionIsExtended(func);
+#ifdef DEBUG
+  Label isObject;
+  masm.branchTestObject(Assembler::Equal, homeObject, &isObject);
+  masm.assumeUnreachable("[[HomeObject]] must be Object");
+  masm.bind(&isObject);
+#endif
+
+  masm.unboxObject(homeObject, ToRegister(lir->output()));
+}
+
+void CodeGenerator::visitHomeObjectSuperBase(LHomeObjectSuperBase* lir) {
+  Register homeObject = ToRegister(lir->homeObject());
+  ValueOperand output = ToOutValue(lir);
+  Register temp = output.scratchReg();
+
+  masm.loadObjProto(homeObject, temp);
+
+#ifdef DEBUG
+  // We won't encounter a lazy proto, because the prototype is guaranteed to
+  // either be a JSFunction or a PlainObject, and only proxy objects can have a
+  // lazy proto.
+  MOZ_ASSERT(uintptr_t(TaggedProto::LazyProto) == 1);
+
+  Label proxyCheckDone;
+  masm.branchPtr(Assembler::NotEqual, temp, ImmWord(1), &proxyCheckDone);
+  masm.assumeUnreachable("Unexpected lazy proto in JSOp::SuperBase");
+  masm.bind(&proxyCheckDone);
+#endif
+
+  Label nullProto, done;
+  masm.branchPtr(Assembler::Equal, temp, ImmWord(0), &nullProto);
+
+  // Box prototype and return
+  masm.tagValue(JSVAL_TYPE_OBJECT, temp, output);
+  masm.jump(&done);
+
+  masm.bind(&nullProto);
+  masm.moveValue(NullValue(), output);
+
+  masm.bind(&done);
+}
+
+template <class T>
+static T* ToConstantObject(MDefinition* def) {
+  MOZ_ASSERT(def->isConstant());
+  return &def->toConstant()->toObject().as<T>();
+}
+
+void CodeGenerator::visitNewLexicalEnvironmentObject(
+    LNewLexicalEnvironmentObject* lir) {
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  auto* templateObj = ToConstantObject<BlockLexicalEnvironmentObject>(
+      lir->mir()->templateObj());
+  auto* scope = &templateObj->scope();
+  gc::Heap initialHeap = gc::Heap::Default;
+
+  using Fn =
+      BlockLexicalEnvironmentObject* (*)(JSContext*, Handle<LexicalScope*>);
+  auto* ool =
+      oolCallVM<Fn, BlockLexicalEnvironmentObject::createWithoutEnclosing>(
+          lir, ArgList(ImmGCPtr(scope)), StoreRegisterTo(output));
+
+  TemplateObject templateObject(templateObj);
+  masm.createGCObject(output, temp, templateObject, initialHeap, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewClassBodyEnvironmentObject(
+    LNewClassBodyEnvironmentObject* lir) {
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  auto* templateObj = ToConstantObject<ClassBodyLexicalEnvironmentObject>(
+      lir->mir()->templateObj());
+  auto* scope = &templateObj->scope();
+  gc::Heap initialHeap = gc::Heap::Default;
+
+  using Fn = ClassBodyLexicalEnvironmentObject* (*)(JSContext*,
+                                                    Handle<ClassBodyScope*>);
+  auto* ool =
+      oolCallVM<Fn, ClassBodyLexicalEnvironmentObject::createWithoutEnclosing>(
+          lir, ArgList(ImmGCPtr(scope)), StoreRegisterTo(output));
+
+  TemplateObject templateObject(templateObj);
+  masm.createGCObject(output, temp, templateObject, initialHeap, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewVarEnvironmentObject(
+    LNewVarEnvironmentObject* lir) {
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  auto* templateObj =
+      ToConstantObject<VarEnvironmentObject>(lir->mir()->templateObj());
+  auto* scope = &templateObj->scope().as<VarScope>();
+  gc::Heap initialHeap = gc::Heap::Default;
+
+  using Fn = VarEnvironmentObject* (*)(JSContext*, Handle<VarScope*>);
+  auto* ool = oolCallVM<Fn, VarEnvironmentObject::createWithoutEnclosing>(
+      lir, ArgList(ImmGCPtr(scope)), StoreRegisterTo(output));
+
+  TemplateObject templateObject(templateObj);
+  masm.createGCObject(output, temp, templateObject, initialHeap, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitGuardShape(LGuardShape* guard) {
+  Register obj = ToRegister(guard->input());
+  Register temp = ToTempRegisterOrInvalid(guard->temp0());
+  Label bail;
+  masm.branchTestObjShape(Assembler::NotEqual, obj, guard->mir()->shape(), temp,
+                          obj, &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardMultipleShapes(LGuardMultipleShapes* guard) {
+  Register obj = ToRegister(guard->object());
+  Register shapeList = ToRegister(guard->shapeList());
+  Register temp = ToRegister(guard->temp0());
+  Register temp2 = ToRegister(guard->temp1());
+  Register temp3 = ToRegister(guard->temp2());
+  Register spectre = ToTempRegisterOrInvalid(guard->temp3());
+
+  Label bail;
+  masm.loadPtr(Address(shapeList, NativeObject::offsetOfElements()), temp);
+  masm.branchTestObjShapeList(Assembler::NotEqual, obj, temp, temp2, temp3,
+                              spectre, &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardProto(LGuardProto* guard) {
+  Register obj = ToRegister(guard->object());
+  Register expected = ToRegister(guard->expected());
+  Register temp = ToRegister(guard->temp0());
+
+  masm.loadObjProto(obj, temp);
+
+  Label bail;
+  masm.branchPtr(Assembler::NotEqual, temp, expected, &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardNullProto(LGuardNullProto* guard) {
+  Register obj = ToRegister(guard->input());
+  Register temp = ToRegister(guard->temp0());
+
+  masm.loadObjProto(obj, temp);
+
+  Label bail;
+  masm.branchTestPtr(Assembler::NonZero, temp, temp, &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardIsNativeObject(LGuardIsNativeObject* guard) {
+  Register obj = ToRegister(guard->input());
+  Register temp = ToRegister(guard->temp0());
+
+  Label bail;
+  masm.branchIfNonNativeObj(obj, temp, &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardGlobalGeneration(LGuardGlobalGeneration* guard) {
+  Register temp = ToRegister(guard->temp0());
+  Label bail;
+
+  masm.load32(AbsoluteAddress(guard->mir()->generationAddr()), temp);
+  masm.branch32(Assembler::NotEqual, temp, Imm32(guard->mir()->expected()),
+                &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardIsProxy(LGuardIsProxy* guard) {
+  Register obj = ToRegister(guard->input());
+  Register temp = ToRegister(guard->temp0());
+
+  Label bail;
+  masm.branchTestObjectIsProxy(false, obj, temp, &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardIsNotProxy(LGuardIsNotProxy* guard) {
+  Register obj = ToRegister(guard->input());
+  Register temp = ToRegister(guard->temp0());
+
+  Label bail;
+  masm.branchTestObjectIsProxy(true, obj, temp, &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardIsNotDOMProxy(LGuardIsNotDOMProxy* guard) {
+  Register proxy = ToRegister(guard->proxy());
+  Register temp = ToRegister(guard->temp0());
+
+  Label bail;
+  masm.branchTestProxyHandlerFamily(Assembler::Equal, proxy, temp,
+                                    GetDOMProxyHandlerFamily(), &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitProxyGet(LProxyGet* lir) {
+  Register proxy = ToRegister(lir->proxy());
+  Register temp = ToRegister(lir->temp0());
+
+  pushArg(lir->mir()->id(), temp);
+  pushArg(proxy);
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleId, MutableHandleValue);
+  callVM<Fn, ProxyGetProperty>(lir);
+}
+
+void CodeGenerator::visitProxyGetByValue(LProxyGetByValue* lir) {
+  Register proxy = ToRegister(lir->proxy());
+  ValueOperand idVal = ToValue(lir, LProxyGetByValue::IdIndex);
+
+  pushArg(idVal);
+  pushArg(proxy);
+
+  using Fn =
+      bool (*)(JSContext*, HandleObject, HandleValue, MutableHandleValue);
+  callVM<Fn, ProxyGetPropertyByValue>(lir);
+}
+
+void CodeGenerator::visitProxyHasProp(LProxyHasProp* lir) {
+  Register proxy = ToRegister(lir->proxy());
+  ValueOperand idVal = ToValue(lir, LProxyHasProp::IdIndex);
+
+  pushArg(idVal);
+  pushArg(proxy);
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleValue, bool*);
+  if (lir->mir()->hasOwn()) {
+    callVM<Fn, ProxyHasOwn>(lir);
+  } else {
+    callVM<Fn, ProxyHas>(lir);
+  }
+}
+
+void CodeGenerator::visitProxySet(LProxySet* lir) {
+  Register proxy = ToRegister(lir->proxy());
+  ValueOperand rhs = ToValue(lir, LProxySet::RhsIndex);
+  Register temp = ToRegister(lir->temp0());
+
+  pushArg(Imm32(lir->mir()->strict()));
+  pushArg(rhs);
+  pushArg(lir->mir()->id(), temp);
+  pushArg(proxy);
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleId, HandleValue, bool);
+  callVM<Fn, ProxySetProperty>(lir);
+}
+
+void CodeGenerator::visitProxySetByValue(LProxySetByValue* lir) {
+  Register proxy = ToRegister(lir->proxy());
+  ValueOperand idVal = ToValue(lir, LProxySetByValue::IdIndex);
+  ValueOperand rhs = ToValue(lir, LProxySetByValue::RhsIndex);
+
+  pushArg(Imm32(lir->mir()->strict()));
+  pushArg(rhs);
+  pushArg(idVal);
+  pushArg(proxy);
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleValue, HandleValue, bool);
+  callVM<Fn, ProxySetPropertyByValue>(lir);
+}
+
+void CodeGenerator::visitCallSetArrayLength(LCallSetArrayLength* lir) {
+  Register obj = ToRegister(lir->obj());
+  ValueOperand rhs = ToValue(lir, LCallSetArrayLength::RhsIndex);
+
+  pushArg(Imm32(lir->mir()->strict()));
+  pushArg(rhs);
+  pushArg(obj);
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleValue, bool);
+  callVM<Fn, jit::SetArrayLength>(lir);
+}
+
+void CodeGenerator::visitMegamorphicLoadSlot(LMegamorphicLoadSlot* lir) {
+  Register obj = ToRegister(lir->object());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+  Register temp3 = ToRegister(lir->temp3());
+  ValueOperand output = ToOutValue(lir);
+
+  Label bail, cacheHit;
+  if (JitOptions.enableWatchtowerMegamorphic) {
+    masm.emitMegamorphicCacheLookup(lir->mir()->name(), obj, temp0, temp1,
+                                    temp2, output, &cacheHit);
+  } else {
+    masm.xorPtr(temp2, temp2);
+  }
+
+  masm.branchIfNonNativeObj(obj, temp0, &bail);
+
+  masm.Push(UndefinedValue());
+  masm.moveStackPtrTo(temp3);
+
+  using Fn = bool (*)(JSContext* cx, JSObject* obj, PropertyKey id,
+                      MegamorphicCache::Entry* cacheEntry, Value* vp);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp0);
+  masm.passABIArg(temp0);
+  masm.passABIArg(obj);
+  masm.movePropertyKey(lir->mir()->name(), temp1);
+  masm.passABIArg(temp1);
+  masm.passABIArg(temp2);
+  masm.passABIArg(temp3);
+
+  masm.callWithABI<Fn, GetNativeDataPropertyPure>();
+
+  MOZ_ASSERT(!output.aliases(ReturnReg));
+  masm.Pop(output);
+
+  masm.branchIfFalseBool(ReturnReg, &bail);
+
+  masm.bind(&cacheHit);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitMegamorphicLoadSlotByValue(
+    LMegamorphicLoadSlotByValue* lir) {
+  Register obj = ToRegister(lir->object());
+  ValueOperand idVal = ToValue(lir, LMegamorphicLoadSlotByValue::IdIndex);
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+  ValueOperand output = ToOutValue(lir);
+
+  Label bail, cacheHit;
+  if (JitOptions.enableWatchtowerMegamorphic) {
+    masm.emitMegamorphicCacheLookupByValue(idVal, obj, temp0, temp1, temp2,
+                                           output, &cacheHit);
+  } else {
+    masm.xorPtr(temp2, temp2);
+  }
+
+  masm.branchIfNonNativeObj(obj, temp0, &bail);
+
+  // idVal will be in vp[0], result will be stored in vp[1].
+  masm.reserveStack(sizeof(Value));
+  masm.Push(idVal);
+  masm.moveStackPtrTo(temp0);
+
+  using Fn = bool (*)(JSContext* cx, JSObject* obj,
+                      MegamorphicCache::Entry* cacheEntry, Value* vp);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp1);
+  masm.passABIArg(temp1);
+  masm.passABIArg(obj);
+  masm.passABIArg(temp2);
+  masm.passABIArg(temp0);
+  masm.callWithABI<Fn, GetNativeDataPropertyByValuePure>();
+
+  MOZ_ASSERT(!idVal.aliases(temp0));
+  masm.storeCallPointerResult(temp0);
+  masm.Pop(idVal);
+
+  uint32_t framePushed = masm.framePushed();
+  Label ok;
+  masm.branchIfTrueBool(temp0, &ok);
+  masm.freeStack(sizeof(Value));  // Discard result Value.
+  masm.jump(&bail);
+
+  masm.bind(&ok);
+  masm.setFramePushed(framePushed);
+  masm.Pop(output);
+
+  masm.bind(&cacheHit);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitMegamorphicStoreSlot(LMegamorphicStoreSlot* lir) {
+  Register obj = ToRegister(lir->object());
+  ValueOperand value = ToValue(lir, LMegamorphicStoreSlot::RhsIndex);
+
+  Register temp0 = ToRegister(lir->temp0());
+#ifndef JS_CODEGEN_X86
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+#endif
+
+  Label cacheHit, done;
+  if (JitOptions.enableWatchtowerMegamorphic) {
+#ifdef JS_CODEGEN_X86
+    masm.emitMegamorphicCachedSetSlot(
+        lir->mir()->name(), obj, temp0, value, &cacheHit,
+        [](MacroAssembler& masm, const Address& addr, MIRType mirType) {
+          EmitPreBarrier(masm, addr, mirType);
+        });
+#else
+    masm.emitMegamorphicCachedSetSlot(
+        lir->mir()->name(), obj, temp0, temp1, temp2, value, &cacheHit,
+        [](MacroAssembler& masm, const Address& addr, MIRType mirType) {
+          EmitPreBarrier(masm, addr, mirType);
+        });
+#endif
+  }
+
+  pushArg(Imm32(lir->mir()->strict()));
+  pushArg(value);
+  pushArg(lir->mir()->name(), temp0);
+  pushArg(obj);
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleId, HandleValue, bool);
+  callVM<Fn, SetPropertyMegamorphic<true>>(lir);
+
+  masm.jump(&done);
+  masm.bind(&cacheHit);
+
+  masm.branchPtrInNurseryChunk(Assembler::Equal, obj, temp0, &done);
+  masm.branchValueIsNurseryCell(Assembler::NotEqual, value, temp0, &done);
+
+  saveVolatile(temp0);
+  emitPostWriteBarrier(obj);
+  restoreVolatile(temp0);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitMegamorphicHasProp(LMegamorphicHasProp* lir) {
+  Register obj = ToRegister(lir->object());
+  ValueOperand idVal = ToValue(lir, LMegamorphicHasProp::IdIndex);
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+  Register output = ToRegister(lir->output());
+
+  Label bail, cacheHit;
+  if (JitOptions.enableWatchtowerMegamorphic) {
+    masm.emitMegamorphicCacheLookupExists(idVal, obj, temp0, temp1, temp2,
+                                          output, &cacheHit,
+                                          lir->mir()->hasOwn());
+  } else {
+    masm.xorPtr(temp2, temp2);
+  }
+
+  masm.branchIfNonNativeObj(obj, temp0, &bail);
+
+  // idVal will be in vp[0], result will be stored in vp[1].
+  masm.reserveStack(sizeof(Value));
+  masm.Push(idVal);
+  masm.moveStackPtrTo(temp0);
+
+  using Fn = bool (*)(JSContext* cx, JSObject* obj,
+                      MegamorphicCache::Entry* cacheEntry, Value* vp);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp1);
+  masm.passABIArg(temp1);
+  masm.passABIArg(obj);
+  masm.passABIArg(temp2);
+  masm.passABIArg(temp0);
+  if (lir->mir()->hasOwn()) {
+    masm.callWithABI<Fn, HasNativeDataPropertyPure<true>>();
+  } else {
+    masm.callWithABI<Fn, HasNativeDataPropertyPure<false>>();
+  }
+
+  MOZ_ASSERT(!idVal.aliases(temp0));
+  masm.storeCallPointerResult(temp0);
+  masm.Pop(idVal);
+
+  uint32_t framePushed = masm.framePushed();
+  Label ok;
+  masm.branchIfTrueBool(temp0, &ok);
+  masm.freeStack(sizeof(Value));  // Discard result Value.
+  masm.jump(&bail);
+
+  masm.bind(&ok);
+  masm.setFramePushed(framePushed);
+  masm.unboxBoolean(Address(masm.getStackPointer(), 0), output);
+  masm.freeStack(sizeof(Value));
+  masm.bind(&cacheHit);
+
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardIsNotArrayBufferMaybeShared(
+    LGuardIsNotArrayBufferMaybeShared* guard) {
+  Register obj = ToRegister(guard->input());
+  Register temp = ToRegister(guard->temp0());
+
+  Label bail;
+  masm.loadObjClassUnsafe(obj, temp);
+  masm.branchPtr(Assembler::Equal, temp, ImmPtr(&ArrayBufferObject::class_),
+                 &bail);
+  masm.branchPtr(Assembler::Equal, temp,
+                 ImmPtr(&SharedArrayBufferObject::class_), &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardIsTypedArray(LGuardIsTypedArray* guard) {
+  Register obj = ToRegister(guard->input());
+  Register temp = ToRegister(guard->temp0());
+
+  Label bail;
+  masm.loadObjClassUnsafe(obj, temp);
+  masm.branchIfClassIsNotTypedArray(temp, &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardObjectIdentity(LGuardObjectIdentity* guard) {
+  Register input = ToRegister(guard->input());
+  Register expected = ToRegister(guard->expected());
+
+  Assembler::Condition cond =
+      guard->mir()->bailOnEquality() ? Assembler::Equal : Assembler::NotEqual;
+  bailoutCmpPtr(cond, input, expected, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardSpecificFunction(LGuardSpecificFunction* guard) {
+  Register input = ToRegister(guard->input());
+  Register expected = ToRegister(guard->expected());
+
+  bailoutCmpPtr(Assembler::NotEqual, input, expected, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardSpecificAtom(LGuardSpecificAtom* guard) {
+  Register str = ToRegister(guard->str());
+  Register scratch = ToRegister(guard->temp0());
+
+  LiveRegisterSet volatileRegs = liveVolatileRegs(guard);
+  volatileRegs.takeUnchecked(scratch);
+
+  Label bail;
+  masm.guardSpecificAtom(str, guard->mir()->atom(), scratch, volatileRegs,
+                         &bail);
+  bailoutFrom(&bail, guard->snapshot());
+}
+
+void CodeGenerator::visitGuardSpecificSymbol(LGuardSpecificSymbol* guard) {
+  Register symbol = ToRegister(guard->symbol());
+
+  bailoutCmpPtr(Assembler::NotEqual, symbol, ImmGCPtr(guard->mir()->expected()),
+                guard->snapshot());
+}
+
+void CodeGenerator::visitGuardSpecificInt32(LGuardSpecificInt32* guard) {
+  Register num = ToRegister(guard->num());
+
+  bailoutCmp32(Assembler::NotEqual, num, Imm32(guard->mir()->expected()),
+               guard->snapshot());
+}
+
+void CodeGenerator::visitGuardStringToIndex(LGuardStringToIndex* lir) {
+  Register str = ToRegister(lir->string());
+  Register output = ToRegister(lir->output());
+
+  Label vmCall, done;
+  masm.loadStringIndexValue(str, output, &vmCall);
+  masm.jump(&done);
+
+  {
+    masm.bind(&vmCall);
+
+    LiveRegisterSet volatileRegs = liveVolatileRegs(lir);
+    volatileRegs.takeUnchecked(output);
+    masm.PushRegsInMask(volatileRegs);
+
+    using Fn = int32_t (*)(JSString* str);
+    masm.setupAlignedABICall();
+    masm.passABIArg(str);
+    masm.callWithABI<Fn, GetIndexFromString>();
+    masm.storeCallInt32Result(output);
+
+    masm.PopRegsInMask(volatileRegs);
+
+    // GetIndexFromString returns a negative value on failure.
+    bailoutTest32(Assembler::Signed, output, output, lir->snapshot());
+  }
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGuardStringToInt32(LGuardStringToInt32* lir) {
+  Register str = ToRegister(lir->string());
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  LiveRegisterSet volatileRegs = liveVolatileRegs(lir);
+
+  Label bail;
+  masm.guardStringToInt32(str, output, temp, volatileRegs, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardStringToDouble(LGuardStringToDouble* lir) {
+  Register str = ToRegister(lir->string());
+  FloatRegister output = ToFloatRegister(lir->output());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  Label vmCall, done;
+  // Use indexed value as fast path if possible.
+  masm.loadStringIndexValue(str, temp0, &vmCall);
+  masm.convertInt32ToDouble(temp0, output);
+  masm.jump(&done);
+  {
+    masm.bind(&vmCall);
+
+    // Reserve stack for holding the result value of the call.
+    masm.reserveStack(sizeof(double));
+    masm.moveStackPtrTo(temp0);
+
+    LiveRegisterSet volatileRegs = liveVolatileRegs(lir);
+    volatileRegs.takeUnchecked(temp0);
+    volatileRegs.takeUnchecked(temp1);
+    masm.PushRegsInMask(volatileRegs);
+
+    using Fn = bool (*)(JSContext* cx, JSString* str, double* result);
+    masm.setupAlignedABICall();
+    masm.loadJSContext(temp1);
+    masm.passABIArg(temp1);
+    masm.passABIArg(str);
+    masm.passABIArg(temp0);
+    masm.callWithABI<Fn, StringToNumberPure>();
+    masm.storeCallPointerResult(temp0);
+
+    masm.PopRegsInMask(volatileRegs);
+
+    Label ok;
+    masm.branchIfTrueBool(temp0, &ok);
+    {
+      // OOM path, recovered by StringToNumberPure.
+      //
+      // Use addToStackPtr instead of freeStack as freeStack tracks stack height
+      // flow-insensitively, and using it here would confuse the stack height
+      // tracking.
+      masm.addToStackPtr(Imm32(sizeof(double)));
+      bailout(lir->snapshot());
+    }
+    masm.bind(&ok);
+    masm.Pop(output);
+  }
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGuardNoDenseElements(LGuardNoDenseElements* guard) {
+  Register obj = ToRegister(guard->input());
+  Register temp = ToRegister(guard->temp0());
+
+  // Load obj->elements.
+  masm.loadPtr(Address(obj, NativeObject::offsetOfElements()), temp);
+
+  // Make sure there are no dense elements.
+  Address initLength(temp, ObjectElements::offsetOfInitializedLength());
+  bailoutCmp32(Assembler::NotEqual, initLength, Imm32(0), guard->snapshot());
+}
+
+void CodeGenerator::visitBooleanToInt64(LBooleanToInt64* lir) {
+  Register input = ToRegister(lir->input());
+  Register64 output = ToOutRegister64(lir);
+
+  masm.move32To64ZeroExtend(input, output);
+}
+
+void CodeGenerator::emitStringToInt64(LInstruction* lir, Register input,
+                                      Register64 output) {
+  Register temp = output.scratchReg();
+
+  saveLive(lir);
+
+  masm.reserveStack(sizeof(uint64_t));
+  masm.moveStackPtrTo(temp);
+  pushArg(temp);
+  pushArg(input);
+
+  using Fn = bool (*)(JSContext*, HandleString, uint64_t*);
+  callVM<Fn, DoStringToInt64>(lir);
+
+  masm.load64(Address(masm.getStackPointer(), 0), output);
+  masm.freeStack(sizeof(uint64_t));
+
+  restoreLiveIgnore(lir, StoreValueTo(output).clobbered());
+}
+
+void CodeGenerator::visitStringToInt64(LStringToInt64* lir) {
+  Register input = ToRegister(lir->input());
+  Register64 output = ToOutRegister64(lir);
+
+  emitStringToInt64(lir, input, output);
+}
+
+void CodeGenerator::visitValueToInt64(LValueToInt64* lir) {
+  ValueOperand input = ToValue(lir, LValueToInt64::InputIndex);
+  Register temp = ToRegister(lir->temp0());
+  Register64 output = ToOutRegister64(lir);
+
+  int checks = 3;
+
+  Label fail, done;
+  // Jump to fail if this is the last check and we fail it,
+  // otherwise to the next test.
+  auto emitTestAndUnbox = [&](auto testAndUnbox) {
+    MOZ_ASSERT(checks > 0);
+
+    checks--;
+    Label notType;
+    Label* target = checks ? &notType : &fail;
+
+    testAndUnbox(target);
+
+    if (checks) {
+      masm.jump(&done);
+      masm.bind(&notType);
+    }
+  };
+
+  Register tag = masm.extractTag(input, temp);
+
+  // BigInt.
+  emitTestAndUnbox([&](Label* target) {
+    masm.branchTestBigInt(Assembler::NotEqual, tag, target);
+    masm.unboxBigInt(input, temp);
+    masm.loadBigInt64(temp, output);
+  });
+
+  // Boolean
+  emitTestAndUnbox([&](Label* target) {
+    masm.branchTestBoolean(Assembler::NotEqual, tag, target);
+    masm.unboxBoolean(input, temp);
+    masm.move32To64ZeroExtend(temp, output);
+  });
+
+  // String
+  emitTestAndUnbox([&](Label* target) {
+    masm.branchTestString(Assembler::NotEqual, tag, target);
+    masm.unboxString(input, temp);
+    emitStringToInt64(lir, temp, output);
+  });
+
+  MOZ_ASSERT(checks == 0);
+
+  bailoutFrom(&fail, lir->snapshot());
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitTruncateBigIntToInt64(LTruncateBigIntToInt64* lir) {
+  Register operand = ToRegister(lir->input());
+  Register64 output = ToOutRegister64(lir);
+
+  masm.loadBigInt64(operand, output);
+}
+
+OutOfLineCode* CodeGenerator::createBigIntOutOfLine(LInstruction* lir,
+                                                    Scalar::Type type,
+                                                    Register64 input,
+                                                    Register output) {
+#if JS_BITS_PER_WORD == 32
+  using Fn = BigInt* (*)(JSContext*, uint32_t, uint32_t);
+  auto args = ArgList(input.low, input.high);
+#else
+  using Fn = BigInt* (*)(JSContext*, uint64_t);
+  auto args = ArgList(input);
+#endif
+
+  if (type == Scalar::BigInt64) {
+    return oolCallVM<Fn, jit::CreateBigIntFromInt64>(lir, args,
+                                                     StoreRegisterTo(output));
+  }
+  MOZ_ASSERT(type == Scalar::BigUint64);
+  return oolCallVM<Fn, jit::CreateBigIntFromUint64>(lir, args,
+                                                    StoreRegisterTo(output));
+}
+
+void CodeGenerator::emitCreateBigInt(LInstruction* lir, Scalar::Type type,
+                                     Register64 input, Register output,
+                                     Register maybeTemp) {
+  OutOfLineCode* ool = createBigIntOutOfLine(lir, type, input, output);
+
+  if (maybeTemp != InvalidReg) {
+    masm.newGCBigInt(output, maybeTemp, initialBigIntHeap(), ool->entry());
+  } else {
+    AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+    regs.take(input);
+    regs.take(output);
+
+    Register temp = regs.takeAny();
+
+    masm.push(temp);
+
+    Label fail, ok;
+    masm.newGCBigInt(output, temp, initialBigIntHeap(), &fail);
+    masm.pop(temp);
+    masm.jump(&ok);
+    masm.bind(&fail);
+    masm.pop(temp);
+    masm.jump(ool->entry());
+    masm.bind(&ok);
+  }
+  masm.initializeBigInt64(type, output, input);
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitInt64ToBigInt(LInt64ToBigInt* lir) {
+  Register64 input = ToRegister64(lir->input());
+  Register temp = ToRegister(lir->temp0());
+  Register output = ToRegister(lir->output());
+
+  emitCreateBigInt(lir, Scalar::BigInt64, input, output, temp);
+}
+
+void CodeGenerator::visitGuardValue(LGuardValue* lir) {
+  ValueOperand input = ToValue(lir, LGuardValue::InputIndex);
+  Value expected = lir->mir()->expected();
+  Label bail;
+  masm.branchTestValue(Assembler::NotEqual, input, expected, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardNullOrUndefined(LGuardNullOrUndefined* lir) {
+  ValueOperand input = ToValue(lir, LGuardNullOrUndefined::InputIndex);
+
+  ScratchTagScope tag(masm, input);
+  masm.splitTagForTest(input, tag);
+
+  Label done;
+  masm.branchTestNull(Assembler::Equal, tag, &done);
+
+  Label bail;
+  masm.branchTestUndefined(Assembler::NotEqual, tag, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGuardIsNotObject(LGuardIsNotObject* lir) {
+  ValueOperand input = ToValue(lir, LGuardIsNotObject::InputIndex);
+
+  Label bail;
+  masm.branchTestObject(Assembler::Equal, input, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardFunctionFlags(LGuardFunctionFlags* lir) {
+  Register function = ToRegister(lir->function());
+
+  Label bail;
+  if (uint16_t flags = lir->mir()->expectedFlags()) {
+    masm.branchTestFunctionFlags(function, flags, Assembler::Zero, &bail);
+  }
+  if (uint16_t flags = lir->mir()->unexpectedFlags()) {
+    masm.branchTestFunctionFlags(function, flags, Assembler::NonZero, &bail);
+  }
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardFunctionIsNonBuiltinCtor(
+    LGuardFunctionIsNonBuiltinCtor* lir) {
+  Register function = ToRegister(lir->function());
+  Register temp = ToRegister(lir->temp0());
+
+  Label bail;
+  masm.branchIfNotFunctionIsNonBuiltinCtor(function, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardFunctionKind(LGuardFunctionKind* lir) {
+  Register function = ToRegister(lir->function());
+  Register temp = ToRegister(lir->temp0());
+
+  Assembler::Condition cond =
+      lir->mir()->bailOnEquality() ? Assembler::Equal : Assembler::NotEqual;
+
+  Label bail;
+  masm.branchFunctionKind(cond, lir->mir()->expected(), function, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardFunctionScript(LGuardFunctionScript* lir) {
+  Register function = ToRegister(lir->function());
+
+  Address scriptAddr(function, JSFunction::offsetOfJitInfoOrScript());
+  bailoutCmpPtr(Assembler::NotEqual, scriptAddr,
+                ImmGCPtr(lir->mir()->expected()), lir->snapshot());
+}
+
+// Out-of-line path to update the store buffer.
+class OutOfLineCallPostWriteBarrier : public OutOfLineCodeBase<CodeGenerator> {
+  LInstruction* lir_;
+  const LAllocation* object_;
+
+ public:
+  OutOfLineCallPostWriteBarrier(LInstruction* lir, const LAllocation* object)
+      : lir_(lir), object_(object) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineCallPostWriteBarrier(this);
+  }
+
+  LInstruction* lir() const { return lir_; }
+  const LAllocation* object() const { return object_; }
+};
+
+static void EmitStoreBufferCheckForConstant(MacroAssembler& masm,
+                                            const gc::TenuredCell* cell,
+                                            AllocatableGeneralRegisterSet& regs,
+                                            Label* exit, Label* callVM) {
+  Register temp = regs.takeAny();
+
+  gc::Arena* arena = cell->arena();
+
+  Register cells = temp;
+  masm.loadPtr(AbsoluteAddress(&arena->bufferedCells()), cells);
+
+  size_t index = gc::ArenaCellSet::getCellIndex(cell);
+  size_t word;
+  uint32_t mask;
+  gc::ArenaCellSet::getWordIndexAndMask(index, &word, &mask);
+  size_t offset = gc::ArenaCellSet::offsetOfBits() + word * sizeof(uint32_t);
+
+  masm.branchTest32(Assembler::NonZero, Address(cells, offset), Imm32(mask),
+                    exit);
+
+  // Check whether this is the sentinel set and if so call the VM to allocate
+  // one for this arena.
+  masm.branchPtr(Assembler::Equal,
+                 Address(cells, gc::ArenaCellSet::offsetOfArena()),
+                 ImmPtr(nullptr), callVM);
+
+  // Add the cell to the set.
+  masm.or32(Imm32(mask), Address(cells, offset));
+  masm.jump(exit);
+
+  regs.add(temp);
+}
+
+static void EmitPostWriteBarrier(MacroAssembler& masm, CompileRuntime* runtime,
+                                 Register objreg, JSObject* maybeConstant,
+                                 bool isGlobal,
+                                 AllocatableGeneralRegisterSet& regs) {
+  MOZ_ASSERT_IF(isGlobal, maybeConstant);
+
+  Label callVM;
+  Label exit;
+
+  Register temp = regs.takeAny();
+
+  // We already have a fast path to check whether a global is in the store
+  // buffer.
+  if (!isGlobal) {
+    if (maybeConstant) {
+      // Check store buffer bitmap directly for known object.
+      EmitStoreBufferCheckForConstant(masm, &maybeConstant->asTenured(), regs,
+                                      &exit, &callVM);
+    } else {
+      // Check one element cache to avoid VM call.
+      masm.loadPtr(AbsoluteAddress(runtime->addressOfLastBufferedWholeCell()),
+                   temp);
+      masm.branchPtr(Assembler::Equal, temp, objreg, &exit);
+    }
+  }
+
+  // Call into the VM to barrier the write.
+  masm.bind(&callVM);
+
+  Register runtimereg = temp;
+  masm.mov(ImmPtr(runtime), runtimereg);
+
+  masm.setupAlignedABICall();
+  masm.passABIArg(runtimereg);
+  masm.passABIArg(objreg);
+  if (isGlobal) {
+    using Fn = void (*)(JSRuntime* rt, GlobalObject* obj);
+    masm.callWithABI<Fn, PostGlobalWriteBarrier>();
+  } else {
+    using Fn = void (*)(JSRuntime* rt, js::gc::Cell* obj);
+    masm.callWithABI<Fn, PostWriteBarrier>();
+  }
+
+  masm.bind(&exit);
+}
+
+void CodeGenerator::emitPostWriteBarrier(const LAllocation* obj) {
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::Volatile());
+
+  Register objreg;
+  JSObject* object = nullptr;
+  bool isGlobal = false;
+  if (obj->isConstant()) {
+    object = &obj->toConstant()->toObject();
+    isGlobal = isGlobalObject(object);
+    objreg = regs.takeAny();
+    masm.movePtr(ImmGCPtr(object), objreg);
+  } else {
+    objreg = ToRegister(obj);
+    regs.takeUnchecked(objreg);
+  }
+
+  EmitPostWriteBarrier(masm, gen->runtime, objreg, object, isGlobal, regs);
+}
+
+// Returns true if `def` might be allocated in the nursery.
+static bool ValueNeedsPostBarrier(MDefinition* def) {
+  if (def->isBox()) {
+    def = def->toBox()->input();
+  }
+  if (def->type() == MIRType::Value) {
+    return true;
+  }
+  return NeedsPostBarrier(def->type());
+}
+
+class OutOfLineElementPostWriteBarrier
+    : public OutOfLineCodeBase<CodeGenerator> {
+  LiveRegisterSet liveVolatileRegs_;
+  const LAllocation* index_;
+  int32_t indexDiff_;
+  Register obj_;
+  Register scratch_;
+
+ public:
+  OutOfLineElementPostWriteBarrier(const LiveRegisterSet& liveVolatileRegs,
+                                   Register obj, const LAllocation* index,
+                                   Register scratch, int32_t indexDiff)
+      : liveVolatileRegs_(liveVolatileRegs),
+        index_(index),
+        indexDiff_(indexDiff),
+        obj_(obj),
+        scratch_(scratch) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineElementPostWriteBarrier(this);
+  }
+
+  const LiveRegisterSet& liveVolatileRegs() const { return liveVolatileRegs_; }
+  const LAllocation* index() const { return index_; }
+  int32_t indexDiff() const { return indexDiff_; }
+
+  Register object() const { return obj_; }
+  Register scratch() const { return scratch_; }
+};
+
+void CodeGenerator::emitElementPostWriteBarrier(
+    MInstruction* mir, const LiveRegisterSet& liveVolatileRegs, Register obj,
+    const LAllocation* index, Register scratch, const ConstantOrRegister& val,
+    int32_t indexDiff) {
+  if (val.constant()) {
+    MOZ_ASSERT_IF(val.value().isGCThing(),
+                  !IsInsideNursery(val.value().toGCThing()));
+    return;
+  }
+
+  TypedOrValueRegister reg = val.reg();
+  if (reg.hasTyped() && !NeedsPostBarrier(reg.type())) {
+    return;
+  }
+
+  auto* ool = new (alloc()) OutOfLineElementPostWriteBarrier(
+      liveVolatileRegs, obj, index, scratch, indexDiff);
+  addOutOfLineCode(ool, mir);
+
+  masm.branchPtrInNurseryChunk(Assembler::Equal, obj, scratch, ool->rejoin());
+
+  if (reg.hasValue()) {
+    masm.branchValueIsNurseryCell(Assembler::Equal, reg.valueReg(), scratch,
+                                  ool->entry());
+  } else {
+    masm.branchPtrInNurseryChunk(Assembler::Equal, reg.typedReg().gpr(),
+                                 scratch, ool->entry());
+  }
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineElementPostWriteBarrier(
+    OutOfLineElementPostWriteBarrier* ool) {
+  Register obj = ool->object();
+  Register scratch = ool->scratch();
+  const LAllocation* index = ool->index();
+  int32_t indexDiff = ool->indexDiff();
+
+  masm.PushRegsInMask(ool->liveVolatileRegs());
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::Volatile());
+  regs.takeUnchecked(obj);
+  regs.takeUnchecked(scratch);
+
+  Register indexReg;
+  if (index->isConstant()) {
+    indexReg = regs.takeAny();
+    masm.move32(Imm32(ToInt32(index) + indexDiff), indexReg);
+  } else {
+    indexReg = ToRegister(index);
+    regs.takeUnchecked(indexReg);
+    if (indexDiff != 0) {
+      masm.add32(Imm32(indexDiff), indexReg);
+    }
+  }
+
+  masm.setupUnalignedABICall(scratch);
+  masm.movePtr(ImmPtr(gen->runtime), scratch);
+  masm.passABIArg(scratch);
+  masm.passABIArg(obj);
+  masm.passABIArg(indexReg);
+  using Fn = void (*)(JSRuntime* rt, JSObject* obj, int32_t index);
+  masm.callWithABI<Fn, PostWriteElementBarrier<IndexInBounds::Yes>>();
+
+  // We don't need a sub32 here because indexReg must be in liveVolatileRegs
+  // if indexDiff is not zero, so it will be restored below.
+  MOZ_ASSERT_IF(indexDiff != 0, ool->liveVolatileRegs().has(indexReg));
+
+  masm.PopRegsInMask(ool->liveVolatileRegs());
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::emitPostWriteBarrier(Register objreg) {
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::Volatile());
+  regs.takeUnchecked(objreg);
+  EmitPostWriteBarrier(masm, gen->runtime, objreg, nullptr, false, regs);
+}
+
+void CodeGenerator::visitOutOfLineCallPostWriteBarrier(
+    OutOfLineCallPostWriteBarrier* ool) {
+  saveLiveVolatile(ool->lir());
+  const LAllocation* obj = ool->object();
+  emitPostWriteBarrier(obj);
+  restoreLiveVolatile(ool->lir());
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::maybeEmitGlobalBarrierCheck(const LAllocation* maybeGlobal,
+                                                OutOfLineCode* ool) {
+  // Check whether an object is a global that we have already barriered before
+  // calling into the VM.
+  //
+  // We only check for the script's global, not other globals within the same
+  // compartment, because we bake in a pointer to realm->globalWriteBarriered
+  // and doing that would be invalid for other realms because they could be
+  // collected before the Ion code is discarded.
+
+  if (!maybeGlobal->isConstant()) {
+    return;
+  }
+
+  JSObject* obj = &maybeGlobal->toConstant()->toObject();
+  if (gen->realm->maybeGlobal() != obj) {
+    return;
+  }
+
+  const uint32_t* addr = gen->realm->addressOfGlobalWriteBarriered();
+  masm.branch32(Assembler::NotEqual, AbsoluteAddress(addr), Imm32(0),
+                ool->rejoin());
+}
+
+template <class LPostBarrierType, MIRType nurseryType>
+void CodeGenerator::visitPostWriteBarrierCommon(LPostBarrierType* lir,
+                                                OutOfLineCode* ool) {
+  static_assert(NeedsPostBarrier(nurseryType));
+
+  addOutOfLineCode(ool, lir->mir());
+
+  Register temp = ToTempRegisterOrInvalid(lir->temp0());
+
+  if (lir->object()->isConstant()) {
+    // Constant nursery objects cannot appear here, see
+    // LIRGenerator::visitPostWriteElementBarrier.
+    MOZ_ASSERT(!IsInsideNursery(&lir->object()->toConstant()->toObject()));
+  } else {
+    masm.branchPtrInNurseryChunk(Assembler::Equal, ToRegister(lir->object()),
+                                 temp, ool->rejoin());
+  }
+
+  maybeEmitGlobalBarrierCheck(lir->object(), ool);
+
+  Register value = ToRegister(lir->value());
+  if constexpr (nurseryType == MIRType::Object) {
+    MOZ_ASSERT(lir->mir()->value()->type() == MIRType::Object);
+  } else if constexpr (nurseryType == MIRType::String) {
+    MOZ_ASSERT(lir->mir()->value()->type() == MIRType::String);
+  } else {
+    static_assert(nurseryType == MIRType::BigInt);
+    MOZ_ASSERT(lir->mir()->value()->type() == MIRType::BigInt);
+  }
+  masm.branchPtrInNurseryChunk(Assembler::Equal, value, temp, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+template <class LPostBarrierType>
+void CodeGenerator::visitPostWriteBarrierCommonV(LPostBarrierType* lir,
+                                                 OutOfLineCode* ool) {
+  addOutOfLineCode(ool, lir->mir());
+
+  Register temp = ToTempRegisterOrInvalid(lir->temp0());
+
+  if (lir->object()->isConstant()) {
+    // Constant nursery objects cannot appear here, see
+    // LIRGenerator::visitPostWriteElementBarrier.
+    MOZ_ASSERT(!IsInsideNursery(&lir->object()->toConstant()->toObject()));
+  } else {
+    masm.branchPtrInNurseryChunk(Assembler::Equal, ToRegister(lir->object()),
+                                 temp, ool->rejoin());
+  }
+
+  maybeEmitGlobalBarrierCheck(lir->object(), ool);
+
+  ValueOperand value = ToValue(lir, LPostBarrierType::ValueIndex);
+  masm.branchValueIsNurseryCell(Assembler::Equal, value, temp, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitPostWriteBarrierO(LPostWriteBarrierO* lir) {
+  auto ool = new (alloc()) OutOfLineCallPostWriteBarrier(lir, lir->object());
+  visitPostWriteBarrierCommon<LPostWriteBarrierO, MIRType::Object>(lir, ool);
+}
+
+void CodeGenerator::visitPostWriteBarrierS(LPostWriteBarrierS* lir) {
+  auto ool = new (alloc()) OutOfLineCallPostWriteBarrier(lir, lir->object());
+  visitPostWriteBarrierCommon<LPostWriteBarrierS, MIRType::String>(lir, ool);
+}
+
+void CodeGenerator::visitPostWriteBarrierBI(LPostWriteBarrierBI* lir) {
+  auto ool = new (alloc()) OutOfLineCallPostWriteBarrier(lir, lir->object());
+  visitPostWriteBarrierCommon<LPostWriteBarrierBI, MIRType::BigInt>(lir, ool);
+}
+
+void CodeGenerator::visitPostWriteBarrierV(LPostWriteBarrierV* lir) {
+  auto ool = new (alloc()) OutOfLineCallPostWriteBarrier(lir, lir->object());
+  visitPostWriteBarrierCommonV(lir, ool);
+}
+
+// Out-of-line path to update the store buffer.
+class OutOfLineCallPostWriteElementBarrier
+    : public OutOfLineCodeBase<CodeGenerator> {
+  LInstruction* lir_;
+  const LAllocation* object_;
+  const LAllocation* index_;
+
+ public:
+  OutOfLineCallPostWriteElementBarrier(LInstruction* lir,
+                                       const LAllocation* object,
+                                       const LAllocation* index)
+      : lir_(lir), object_(object), index_(index) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineCallPostWriteElementBarrier(this);
+  }
+
+  LInstruction* lir() const { return lir_; }
+
+  const LAllocation* object() const { return object_; }
+
+  const LAllocation* index() const { return index_; }
+};
+
+void CodeGenerator::visitOutOfLineCallPostWriteElementBarrier(
+    OutOfLineCallPostWriteElementBarrier* ool) {
+  saveLiveVolatile(ool->lir());
+
+  const LAllocation* obj = ool->object();
+  const LAllocation* index = ool->index();
+
+  Register objreg = obj->isConstant() ? InvalidReg : ToRegister(obj);
+  Register indexreg = ToRegister(index);
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::Volatile());
+  regs.takeUnchecked(indexreg);
+
+  if (obj->isConstant()) {
+    objreg = regs.takeAny();
+    masm.movePtr(ImmGCPtr(&obj->toConstant()->toObject()), objreg);
+  } else {
+    regs.takeUnchecked(objreg);
+  }
+
+  Register runtimereg = regs.takeAny();
+  using Fn = void (*)(JSRuntime* rt, JSObject* obj, int32_t index);
+  masm.setupAlignedABICall();
+  masm.mov(ImmPtr(gen->runtime), runtimereg);
+  masm.passABIArg(runtimereg);
+  masm.passABIArg(objreg);
+  masm.passABIArg(indexreg);
+  masm.callWithABI<Fn, PostWriteElementBarrier<IndexInBounds::Maybe>>();
+
+  restoreLiveVolatile(ool->lir());
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitPostWriteElementBarrierO(
+    LPostWriteElementBarrierO* lir) {
+  auto ool = new (alloc())
+      OutOfLineCallPostWriteElementBarrier(lir, lir->object(), lir->index());
+  visitPostWriteBarrierCommon<LPostWriteElementBarrierO, MIRType::Object>(lir,
+                                                                          ool);
+}
+
+void CodeGenerator::visitPostWriteElementBarrierS(
+    LPostWriteElementBarrierS* lir) {
+  auto ool = new (alloc())
+      OutOfLineCallPostWriteElementBarrier(lir, lir->object(), lir->index());
+  visitPostWriteBarrierCommon<LPostWriteElementBarrierS, MIRType::String>(lir,
+                                                                          ool);
+}
+
+void CodeGenerator::visitPostWriteElementBarrierBI(
+    LPostWriteElementBarrierBI* lir) {
+  auto ool = new (alloc())
+      OutOfLineCallPostWriteElementBarrier(lir, lir->object(), lir->index());
+  visitPostWriteBarrierCommon<LPostWriteElementBarrierBI, MIRType::BigInt>(lir,
+                                                                           ool);
+}
+
+void CodeGenerator::visitPostWriteElementBarrierV(
+    LPostWriteElementBarrierV* lir) {
+  auto ool = new (alloc())
+      OutOfLineCallPostWriteElementBarrier(lir, lir->object(), lir->index());
+  visitPostWriteBarrierCommonV(lir, ool);
+}
+
+void CodeGenerator::visitAssertCanElidePostWriteBarrier(
+    LAssertCanElidePostWriteBarrier* lir) {
+  Register object = ToRegister(lir->object());
+  ValueOperand value =
+      ToValue(lir, LAssertCanElidePostWriteBarrier::ValueIndex);
+  Register temp = ToRegister(lir->temp0());
+
+  Label ok;
+  masm.branchPtrInNurseryChunk(Assembler::Equal, object, temp, &ok);
+  masm.branchValueIsNurseryCell(Assembler::NotEqual, value, temp, &ok);
+
+  masm.assumeUnreachable("Unexpected missing post write barrier");
+
+  masm.bind(&ok);
+}
+
+template <typename LCallIns>
+void CodeGenerator::emitCallNative(LCallIns* call, JSNative native) {
+  MCallBase* mir = call->mir();
+
+  uint32_t unusedStack = UnusedStackBytesForCall(mir->paddedNumStackArgs());
+
+  // Registers used for callWithABI() argument-passing.
+  const Register argContextReg = ToRegister(call->getArgContextReg());
+  const Register argUintNReg = ToRegister(call->getArgUintNReg());
+  const Register argVpReg = ToRegister(call->getArgVpReg());
+
+  // Misc. temporary registers.
+  const Register tempReg = ToRegister(call->getTempReg());
+
+  DebugOnly<uint32_t> initialStack = masm.framePushed();
+
+  masm.checkStackAlignment();
+
+  // Native functions have the signature:
+  //  bool (*)(JSContext*, unsigned, Value* vp)
+  // Where vp[0] is space for an outparam, vp[1] is |this|, and vp[2] onward
+  // are the function arguments.
+
+  // Allocate space for the outparam, moving the StackPointer to what will be
+  // &vp[1].
+  masm.adjustStack(unusedStack);
+
+  // Push a Value containing the callee object: natives are allowed to access
+  // their callee before setting the return value. The StackPointer is moved
+  // to &vp[0].
+  if constexpr (std::is_same_v<LCallIns, LCallClassHook>) {
+    Register calleeReg = ToRegister(call->getCallee());
+    masm.Push(TypedOrValueRegister(MIRType::Object, AnyRegister(calleeReg)));
+
+    if (call->mir()->maybeCrossRealm()) {
+      masm.switchToObjectRealm(calleeReg, tempReg);
+    }
+  } else {
+    WrappedFunction* target = call->getSingleTarget();
+    masm.Push(ObjectValue(*target->rawNativeJSFunction()));
+
+    if (call->mir()->maybeCrossRealm()) {
+      masm.movePtr(ImmGCPtr(target->rawNativeJSFunction()), tempReg);
+      masm.switchToObjectRealm(tempReg, tempReg);
+    }
+  }
+
+  // Preload arguments into registers.
+  masm.loadJSContext(argContextReg);
+  masm.move32(Imm32(call->mir()->numActualArgs()), argUintNReg);
+  masm.moveStackPtrTo(argVpReg);
+
+  masm.Push(argUintNReg);
+
+  // Construct native exit frame.
+  uint32_t safepointOffset = masm.buildFakeExitFrame(tempReg);
+  masm.enterFakeExitFrameForNative(argContextReg, tempReg,
+                                   call->mir()->isConstructing());
+
+  markSafepointAt(safepointOffset, call);
+
+  // Construct and execute call.
+  masm.setupAlignedABICall();
+  masm.passABIArg(argContextReg);
+  masm.passABIArg(argUintNReg);
+  masm.passABIArg(argVpReg);
+
+  ensureOsiSpace();
+  // If we're using a simulator build, `native` will already point to the
+  // simulator's call-redirection code for LCallClassHook. Load the address in
+  // a register first so that we don't try to redirect it a second time.
+  bool emittedCall = false;
+#ifdef JS_SIMULATOR
+  if constexpr (std::is_same_v<LCallIns, LCallClassHook>) {
+    masm.movePtr(ImmPtr(native), tempReg);
+    masm.callWithABI(tempReg);
+    emittedCall = true;
+  }
+#endif
+  if (!emittedCall) {
+    masm.callWithABI(DynamicFunction<JSNative>(native), MoveOp::GENERAL,
+                     CheckUnsafeCallWithABI::DontCheckHasExitFrame);
+  }
+
+  // Test for failure.
+  masm.branchIfFalseBool(ReturnReg, masm.failureLabel());
+
+  if (call->mir()->maybeCrossRealm()) {
+    masm.switchToRealm(gen->realm->realmPtr(), ReturnReg);
+  }
+
+  // Load the outparam vp[0] into output register(s).
+  masm.loadValue(
+      Address(masm.getStackPointer(), NativeExitFrameLayout::offsetOfResult()),
+      JSReturnOperand);
+
+  // Until C++ code is instrumented against Spectre, prevent speculative
+  // execution from returning any private data.
+  if (JitOptions.spectreJitToCxxCalls && !call->mir()->ignoresReturnValue() &&
+      mir->hasLiveDefUses()) {
+    masm.speculationBarrier();
+  }
+
+  // The next instruction is removing the footer of the exit frame, so there
+  // is no need for leaveFakeExitFrame.
+
+  // Move the StackPointer back to its original location, unwinding the native
+  // exit frame.
+  masm.adjustStack(NativeExitFrameLayout::Size() - unusedStack);
+  MOZ_ASSERT(masm.framePushed() == initialStack);
+}
+
+void CodeGenerator::visitCallNative(LCallNative* call) {
+  WrappedFunction* target = call->getSingleTarget();
+  MOZ_ASSERT(target);
+  MOZ_ASSERT(target->isNativeWithoutJitEntry());
+
+  JSNative native = target->native();
+  if (call->ignoresReturnValue() && target->hasJitInfo()) {
+    const JSJitInfo* jitInfo = target->jitInfo();
+    if (jitInfo->type() == JSJitInfo::IgnoresReturnValueNative) {
+      native = jitInfo->ignoresReturnValueMethod;
+    }
+  }
+  emitCallNative(call, native);
+}
+
+void CodeGenerator::visitCallClassHook(LCallClassHook* call) {
+  emitCallNative(call, call->mir()->target());
+}
+
+static void LoadDOMPrivate(MacroAssembler& masm, Register obj, Register priv,
+                           DOMObjectKind kind) {
+  // Load the value in DOM_OBJECT_SLOT for a native or proxy DOM object. This
+  // will be in the first slot but may be fixed or non-fixed.
+  MOZ_ASSERT(obj != priv);
+
+  switch (kind) {
+    case DOMObjectKind::Native:
+      // If it's a native object, the value must be in a fixed slot.
+      // See CanAttachDOMCall in CacheIR.cpp.
+      masm.debugAssertObjHasFixedSlots(obj, priv);
+      masm.loadPrivate(Address(obj, NativeObject::getFixedSlotOffset(0)), priv);
+      break;
+    case DOMObjectKind::Proxy: {
+#ifdef DEBUG
+      // Sanity check: it must be a DOM proxy.
+      Label isDOMProxy;
+      masm.branchTestProxyHandlerFamily(
+          Assembler::Equal, obj, priv, GetDOMProxyHandlerFamily(), &isDOMProxy);
+      masm.assumeUnreachable("Expected a DOM proxy");
+      masm.bind(&isDOMProxy);
+#endif
+      masm.loadPtr(Address(obj, ProxyObject::offsetOfReservedSlots()), priv);
+      masm.loadPrivate(
+          Address(priv, js::detail::ProxyReservedSlots::offsetOfSlot(0)), priv);
+      break;
+    }
+  }
+}
+
+void CodeGenerator::visitCallDOMNative(LCallDOMNative* call) {
+  WrappedFunction* target = call->getSingleTarget();
+  MOZ_ASSERT(target);
+  MOZ_ASSERT(target->isNativeWithoutJitEntry());
+  MOZ_ASSERT(target->hasJitInfo());
+  MOZ_ASSERT(call->mir()->isCallDOMNative());
+
+  int unusedStack = UnusedStackBytesForCall(call->mir()->paddedNumStackArgs());
+
+  // Registers used for callWithABI() argument-passing.
+  const Register argJSContext = ToRegister(call->getArgJSContext());
+  const Register argObj = ToRegister(call->getArgObj());
+  const Register argPrivate = ToRegister(call->getArgPrivate());
+  const Register argArgs = ToRegister(call->getArgArgs());
+
+  DebugOnly<uint32_t> initialStack = masm.framePushed();
+
+  masm.checkStackAlignment();
+
+  // DOM methods have the signature:
+  //  bool (*)(JSContext*, HandleObject, void* private, const
+  //  JSJitMethodCallArgs& args)
+  // Where args is initialized from an argc and a vp, vp[0] is space for an
+  // outparam and the callee, vp[1] is |this|, and vp[2] onward are the
+  // function arguments.  Note that args stores the argv, not the vp, and
+  // argv == vp + 2.
+
+  // Nestle the stack up against the pushed arguments, leaving StackPointer at
+  // &vp[1]
+  masm.adjustStack(unusedStack);
+  // argObj is filled with the extracted object, then returned.
+  Register obj = masm.extractObject(Address(masm.getStackPointer(), 0), argObj);
+  MOZ_ASSERT(obj == argObj);
+
+  // Push a Value containing the callee object: natives are allowed to access
+  // their callee before setting the return value. After this the StackPointer
+  // points to &vp[0].
+  masm.Push(ObjectValue(*target->rawNativeJSFunction()));
+
+  // Now compute the argv value.  Since StackPointer is pointing to &vp[0] and
+  // argv is &vp[2] we just need to add 2*sizeof(Value) to the current
+  // StackPointer.
+  static_assert(JSJitMethodCallArgsTraits::offsetOfArgv == 0);
+  static_assert(JSJitMethodCallArgsTraits::offsetOfArgc ==
+                IonDOMMethodExitFrameLayoutTraits::offsetOfArgcFromArgv);
+  masm.computeEffectiveAddress(
+      Address(masm.getStackPointer(), 2 * sizeof(Value)), argArgs);
+
+  LoadDOMPrivate(masm, obj, argPrivate,
+                 static_cast<MCallDOMNative*>(call->mir())->objectKind());
+
+  // Push argc from the call instruction into what will become the IonExitFrame
+  masm.Push(Imm32(call->numActualArgs()));
+
+  // Push our argv onto the stack
+  masm.Push(argArgs);
+  // And store our JSJitMethodCallArgs* in argArgs.
+  masm.moveStackPtrTo(argArgs);
+
+  // Push |this| object for passing HandleObject. We push after argc to
+  // maintain the same sp-relative location of the object pointer with other
+  // DOMExitFrames.
+  masm.Push(argObj);
+  masm.moveStackPtrTo(argObj);
+
+  if (call->mir()->maybeCrossRealm()) {
+    // We use argJSContext as scratch register here.
+    masm.movePtr(ImmGCPtr(target->rawNativeJSFunction()), argJSContext);
+    masm.switchToObjectRealm(argJSContext, argJSContext);
+  }
+
+  // Construct native exit frame.
+  uint32_t safepointOffset = masm.buildFakeExitFrame(argJSContext);
+  masm.loadJSContext(argJSContext);
+  masm.enterFakeExitFrame(argJSContext, argJSContext,
+                          ExitFrameType::IonDOMMethod);
+
+  markSafepointAt(safepointOffset, call);
+
+  // Construct and execute call.
+  masm.setupAlignedABICall();
+  masm.loadJSContext(argJSContext);
+  masm.passABIArg(argJSContext);
+  masm.passABIArg(argObj);
+  masm.passABIArg(argPrivate);
+  masm.passABIArg(argArgs);
+  ensureOsiSpace();
+  masm.callWithABI(DynamicFunction<JSJitMethodOp>(target->jitInfo()->method),
+                   MoveOp::GENERAL,
+                   CheckUnsafeCallWithABI::DontCheckHasExitFrame);
+
+  if (target->jitInfo()->isInfallible) {
+    masm.loadValue(Address(masm.getStackPointer(),
+                           IonDOMMethodExitFrameLayout::offsetOfResult()),
+                   JSReturnOperand);
+  } else {
+    // Test for failure.
+    masm.branchIfFalseBool(ReturnReg, masm.exceptionLabel());
+
+    // Load the outparam vp[0] into output register(s).
+    masm.loadValue(Address(masm.getStackPointer(),
+                           IonDOMMethodExitFrameLayout::offsetOfResult()),
+                   JSReturnOperand);
+  }
+
+  // Switch back to the current realm if needed. Note: if the DOM method threw
+  // an exception, the exception handler will do this.
+  if (call->mir()->maybeCrossRealm()) {
+    static_assert(!JSReturnOperand.aliases(ReturnReg),
+                  "Clobbering ReturnReg should not affect the return value");
+    masm.switchToRealm(gen->realm->realmPtr(), ReturnReg);
+  }
+
+  // Until C++ code is instrumented against Spectre, prevent speculative
+  // execution from returning any private data.
+  if (JitOptions.spectreJitToCxxCalls && call->mir()->hasLiveDefUses()) {
+    masm.speculationBarrier();
+  }
+
+  // The next instruction is removing the footer of the exit frame, so there
+  // is no need for leaveFakeExitFrame.
+
+  // Move the StackPointer back to its original location, unwinding the native
+  // exit frame.
+  masm.adjustStack(IonDOMMethodExitFrameLayout::Size() - unusedStack);
+  MOZ_ASSERT(masm.framePushed() == initialStack);
+}
+
+void CodeGenerator::visitCallGetIntrinsicValue(LCallGetIntrinsicValue* lir) {
+  pushArg(ImmGCPtr(lir->mir()->name()));
+
+  using Fn = bool (*)(JSContext* cx, Handle<PropertyName*>, MutableHandleValue);
+  callVM<Fn, GetIntrinsicValue>(lir);
+}
+
+void CodeGenerator::emitCallInvokeFunction(
+    LInstruction* call, Register calleereg, bool constructing,
+    bool ignoresReturnValue, uint32_t argc, uint32_t unusedStack) {
+  // Nestle %esp up to the argument vector.
+  // Each path must account for framePushed_ separately, for callVM to be valid.
+  masm.freeStack(unusedStack);
+
+  pushArg(masm.getStackPointer());  // argv.
+  pushArg(Imm32(argc));             // argc.
+  pushArg(Imm32(ignoresReturnValue));
+  pushArg(Imm32(constructing));  // constructing.
+  pushArg(calleereg);            // JSFunction*.
+
+  using Fn = bool (*)(JSContext*, HandleObject, bool, bool, uint32_t, Value*,
+                      MutableHandleValue);
+  callVM<Fn, jit::InvokeFunction>(call);
+
+  // Un-nestle %esp from the argument vector. No prefix was pushed.
+  masm.reserveStack(unusedStack);
+}
+
+void CodeGenerator::visitCallGeneric(LCallGeneric* call) {
+  Register calleereg = ToRegister(call->getFunction());
+  Register objreg = ToRegister(call->getTempObject());
+  Register nargsreg = ToRegister(call->getNargsReg());
+  uint32_t unusedStack =
+      UnusedStackBytesForCall(call->mir()->paddedNumStackArgs());
+  Label invoke, thunk, makeCall, end;
+
+  // Known-target case is handled by LCallKnown.
+  MOZ_ASSERT(!call->hasSingleTarget());
+
+  masm.checkStackAlignment();
+
+  // Guard that calleereg is actually a function object.
+  if (call->mir()->needsClassCheck()) {
+    masm.branchTestObjIsFunction(Assembler::NotEqual, calleereg, nargsreg,
+                                 calleereg, &invoke);
+  }
+
+  // Guard that callee allows the [[Call]] or [[Construct]] operation required.
+  if (call->mir()->isConstructing()) {
+    masm.branchTestFunctionFlags(calleereg, FunctionFlags::CONSTRUCTOR,
+                                 Assembler::Zero, &invoke);
+  } else {
+    masm.branchFunctionKind(Assembler::Equal, FunctionFlags::ClassConstructor,
+                            calleereg, objreg, &invoke);
+  }
+
+  // Use the slow path if CreateThis was unable to create the |this| object.
+  if (call->mir()->needsThisCheck()) {
+    MOZ_ASSERT(call->mir()->isConstructing());
+    Address thisAddr(masm.getStackPointer(), unusedStack);
+    masm.branchTestNull(Assembler::Equal, thisAddr, &invoke);
+  } else {
+#ifdef DEBUG
+    if (call->mir()->isConstructing()) {
+      Address thisAddr(masm.getStackPointer(), unusedStack);
+      Label ok;
+      masm.branchTestNull(Assembler::NotEqual, thisAddr, &ok);
+      masm.assumeUnreachable("Unexpected null this-value");
+      masm.bind(&ok);
+    }
+#endif
+  }
+
+  // Load jitCodeRaw for callee if it exists.
+  masm.branchIfFunctionHasNoJitEntry(calleereg, call->mir()->isConstructing(),
+                                     &invoke);
+  masm.loadJitCodeRaw(calleereg, objreg);
+
+  // Target may be a different realm even if same compartment.
+  if (call->mir()->maybeCrossRealm()) {
+    masm.switchToObjectRealm(calleereg, nargsreg);
+  }
+
+  // Nestle the StackPointer up to the argument vector.
+  masm.freeStack(unusedStack);
+
+  // Construct the JitFrameLayout.
+  masm.PushCalleeToken(calleereg, call->mir()->isConstructing());
+  masm.PushFrameDescriptorForJitCall(FrameType::IonJS, call->numActualArgs());
+
+  // Check whether the provided arguments satisfy target argc.
+  // We cannot have lowered to LCallGeneric with a known target. Assert that we
+  // didn't add any undefineds in WarpBuilder. NB: MCall::numStackArgs includes
+  // |this|.
+  DebugOnly<unsigned> numNonArgsOnStack = 1 + call->isConstructing();
+  MOZ_ASSERT(call->numActualArgs() ==
+             call->mir()->numStackArgs() - numNonArgsOnStack);
+  masm.loadFunctionArgCount(calleereg, nargsreg);
+  masm.branch32(Assembler::Above, nargsreg, Imm32(call->numActualArgs()),
+                &thunk);
+  masm.jump(&makeCall);
+
+  // Argument fixup needed. Load the ArgumentsRectifier.
+  masm.bind(&thunk);
+  {
+    TrampolinePtr argumentsRectifier =
+        gen->jitRuntime()->getArgumentsRectifier();
+    masm.movePtr(argumentsRectifier, objreg);
+  }
+
+  // Finally call the function in objreg.
+  masm.bind(&makeCall);
+  ensureOsiSpace();
+  uint32_t callOffset = masm.callJit(objreg);
+  markSafepointAt(callOffset, call);
+
+  if (call->mir()->maybeCrossRealm()) {
+    static_assert(!JSReturnOperand.aliases(ReturnReg),
+                  "ReturnReg available as scratch after scripted calls");
+    masm.switchToRealm(gen->realm->realmPtr(), ReturnReg);
+  }
+
+  // Restore stack pointer: pop JitFrameLayout fields still left on the stack
+  // and undo the earlier |freeStack(unusedStack)|.
+  int prefixGarbage =
+      sizeof(JitFrameLayout) - JitFrameLayout::bytesPoppedAfterCall();
+  masm.adjustStack(prefixGarbage - unusedStack);
+  masm.jump(&end);
+
+  // Handle uncompiled or native functions.
+  masm.bind(&invoke);
+  emitCallInvokeFunction(call, calleereg, call->isConstructing(),
+                         call->ignoresReturnValue(), call->numActualArgs(),
+                         unusedStack);
+
+  masm.bind(&end);
+
+  // If the return value of the constructing function is Primitive,
+  // replace the return value with the Object from CreateThis.
+  if (call->mir()->isConstructing()) {
+    Label notPrimitive;
+    masm.branchTestPrimitive(Assembler::NotEqual, JSReturnOperand,
+                             &notPrimitive);
+    masm.loadValue(Address(masm.getStackPointer(), unusedStack),
+                   JSReturnOperand);
+#ifdef DEBUG
+    masm.branchTestPrimitive(Assembler::NotEqual, JSReturnOperand,
+                             &notPrimitive);
+    masm.assumeUnreachable("CreateThis creates an object");
+#endif
+    masm.bind(&notPrimitive);
+  }
+}
+
+void CodeGenerator::visitCallKnown(LCallKnown* call) {
+  Register calleereg = ToRegister(call->getFunction());
+  Register objreg = ToRegister(call->getTempObject());
+  uint32_t unusedStack =
+      UnusedStackBytesForCall(call->mir()->paddedNumStackArgs());
+  WrappedFunction* target = call->getSingleTarget();
+
+  // Native single targets (except wasm) are handled by LCallNative.
+  MOZ_ASSERT(target->hasJitEntry());
+
+  // Missing arguments must have been explicitly appended by WarpBuilder.
+  DebugOnly<unsigned> numNonArgsOnStack = 1 + call->isConstructing();
+  MOZ_ASSERT(target->nargs() <=
+             call->mir()->numStackArgs() - numNonArgsOnStack);
+
+  MOZ_ASSERT_IF(call->isConstructing(), target->isConstructor());
+
+  masm.checkStackAlignment();
+
+  if (target->isClassConstructor() && !call->isConstructing()) {
+    emitCallInvokeFunction(call, calleereg, call->isConstructing(),
+                           call->ignoresReturnValue(), call->numActualArgs(),
+                           unusedStack);
+    return;
+  }
+
+  MOZ_ASSERT_IF(target->isClassConstructor(), call->isConstructing());
+
+  MOZ_ASSERT(!call->mir()->needsThisCheck());
+
+  if (call->mir()->maybeCrossRealm()) {
+    masm.switchToObjectRealm(calleereg, objreg);
+  }
+
+  masm.loadJitCodeRaw(calleereg, objreg);
+
+  // Nestle the StackPointer up to the argument vector.
+  masm.freeStack(unusedStack);
+
+  // Construct the JitFrameLayout.
+  masm.PushCalleeToken(calleereg, call->mir()->isConstructing());
+  masm.PushFrameDescriptorForJitCall(FrameType::IonJS, call->numActualArgs());
+
+  // Finally call the function in objreg.
+  ensureOsiSpace();
+  uint32_t callOffset = masm.callJit(objreg);
+  markSafepointAt(callOffset, call);
+
+  if (call->mir()->maybeCrossRealm()) {
+    static_assert(!JSReturnOperand.aliases(ReturnReg),
+                  "ReturnReg available as scratch after scripted calls");
+    masm.switchToRealm(gen->realm->realmPtr(), ReturnReg);
+  }
+
+  // Restore stack pointer: pop JitFrameLayout fields still left on the stack
+  // and undo the earlier |freeStack(unusedStack)|.
+  int prefixGarbage =
+      sizeof(JitFrameLayout) - JitFrameLayout::bytesPoppedAfterCall();
+  masm.adjustStack(prefixGarbage - unusedStack);
+
+  // If the return value of the constructing function is Primitive,
+  // replace the return value with the Object from CreateThis.
+  if (call->mir()->isConstructing()) {
+    Label notPrimitive;
+    masm.branchTestPrimitive(Assembler::NotEqual, JSReturnOperand,
+                             &notPrimitive);
+    masm.loadValue(Address(masm.getStackPointer(), unusedStack),
+                   JSReturnOperand);
+#ifdef DEBUG
+    masm.branchTestPrimitive(Assembler::NotEqual, JSReturnOperand,
+                             &notPrimitive);
+    masm.assumeUnreachable("CreateThis creates an object");
+#endif
+    masm.bind(&notPrimitive);
+  }
+}
+
+template <typename T>
+void CodeGenerator::emitCallInvokeFunction(T* apply) {
+  Register objreg = ToRegister(apply->getTempObject());
+
+  // Push the space used by the arguments.
+  masm.moveStackPtrTo(objreg);
+
+  pushArg(objreg);                                     // argv.
+  pushArg(ToRegister(apply->getArgc()));               // argc.
+  pushArg(Imm32(apply->mir()->ignoresReturnValue()));  // ignoresReturnValue.
+  pushArg(Imm32(apply->mir()->isConstructing()));      // isConstructing.
+  pushArg(ToRegister(apply->getFunction()));           // JSFunction*.
+
+  using Fn = bool (*)(JSContext*, HandleObject, bool, bool, uint32_t, Value*,
+                      MutableHandleValue);
+  callVM<Fn, jit::InvokeFunction>(apply);
+}
+
+// Do not bailout after the execution of this function since the stack no longer
+// correspond to what is expected by the snapshots.
+void CodeGenerator::emitAllocateSpaceForApply(Register argcreg,
+                                              Register scratch) {
+  // Use scratch register to calculate stack space (including padding).
+  masm.movePtr(argcreg, scratch);
+
+  // Align the JitFrameLayout on the JitStackAlignment.
+  if (JitStackValueAlignment > 1) {
+    MOZ_ASSERT(frameSize() % JitStackAlignment == 0,
+               "Stack padding assumes that the frameSize is correct");
+    MOZ_ASSERT(JitStackValueAlignment == 2);
+    Label noPaddingNeeded;
+    // if the number of arguments is odd, then we do not need any padding.
+    masm.branchTestPtr(Assembler::NonZero, argcreg, Imm32(1), &noPaddingNeeded);
+    masm.addPtr(Imm32(1), scratch);
+    masm.bind(&noPaddingNeeded);
+  }
+
+  // Reserve space for copying the arguments.
+  NativeObject::elementsSizeMustNotOverflow();
+  masm.lshiftPtr(Imm32(ValueShift), scratch);
+  masm.subFromStackPtr(scratch);
+
+#ifdef DEBUG
+  // Put a magic value in the space reserved for padding. Note, this code
+  // cannot be merged with the previous test, as not all architectures can
+  // write below their stack pointers.
+  if (JitStackValueAlignment > 1) {
+    MOZ_ASSERT(JitStackValueAlignment == 2);
+    Label noPaddingNeeded;
+    // if the number of arguments is odd, then we do not need any padding.
+    masm.branchTestPtr(Assembler::NonZero, argcreg, Imm32(1), &noPaddingNeeded);
+    BaseValueIndex dstPtr(masm.getStackPointer(), argcreg);
+    masm.storeValue(MagicValue(JS_ARG_POISON), dstPtr);
+    masm.bind(&noPaddingNeeded);
+  }
+#endif
+}
+
+// Do not bailout after the execution of this function since the stack no longer
+// correspond to what is expected by the snapshots.
+void CodeGenerator::emitAllocateSpaceForConstructAndPushNewTarget(
+    Register argcreg, Register newTargetAndScratch) {
+  // Align the JitFrameLayout on the JitStackAlignment. Contrary to
+  // |emitAllocateSpaceForApply()|, we're always pushing a magic value, because
+  // we can't write to |newTargetAndScratch| before |new.target| has
+  // been pushed onto the stack.
+  if (JitStackValueAlignment > 1) {
+    MOZ_ASSERT(frameSize() % JitStackAlignment == 0,
+               "Stack padding assumes that the frameSize is correct");
+    MOZ_ASSERT(JitStackValueAlignment == 2);
+
+    Label noPaddingNeeded;
+    // If the number of arguments is even, then we do not need any padding.
+    masm.branchTestPtr(Assembler::Zero, argcreg, Imm32(1), &noPaddingNeeded);
+    masm.pushValue(MagicValue(JS_ARG_POISON));
+    masm.bind(&noPaddingNeeded);
+  }
+
+  // Push |new.target| after the padding value, but before any arguments.
+  masm.pushValue(JSVAL_TYPE_OBJECT, newTargetAndScratch);
+
+  // Use newTargetAndScratch to calculate stack space (including padding).
+  masm.movePtr(argcreg, newTargetAndScratch);
+
+  // Reserve space for copying the arguments.
+  NativeObject::elementsSizeMustNotOverflow();
+  masm.lshiftPtr(Imm32(ValueShift), newTargetAndScratch);
+  masm.subFromStackPtr(newTargetAndScratch);
+}
+
+// Destroys argvIndex and copyreg.
+void CodeGenerator::emitCopyValuesForApply(Register argvSrcBase,
+                                           Register argvIndex, Register copyreg,
+                                           size_t argvSrcOffset,
+                                           size_t argvDstOffset) {
+  Label loop;
+  masm.bind(&loop);
+
+  // As argvIndex is off by 1, and we use the decBranchPtr instruction
+  // to loop back, we have to substract the size of the word which are
+  // copied.
+  BaseValueIndex srcPtr(argvSrcBase, argvIndex,
+                        int32_t(argvSrcOffset) - sizeof(void*));
+  BaseValueIndex dstPtr(masm.getStackPointer(), argvIndex,
+                        int32_t(argvDstOffset) - sizeof(void*));
+  masm.loadPtr(srcPtr, copyreg);
+  masm.storePtr(copyreg, dstPtr);
+
+  // Handle 32 bits architectures.
+  if (sizeof(Value) == 2 * sizeof(void*)) {
+    BaseValueIndex srcPtrLow(argvSrcBase, argvIndex,
+                             int32_t(argvSrcOffset) - 2 * sizeof(void*));
+    BaseValueIndex dstPtrLow(masm.getStackPointer(), argvIndex,
+                             int32_t(argvDstOffset) - 2 * sizeof(void*));
+    masm.loadPtr(srcPtrLow, copyreg);
+    masm.storePtr(copyreg, dstPtrLow);
+  }
+
+  masm.decBranchPtr(Assembler::NonZero, argvIndex, Imm32(1), &loop);
+}
+
+void CodeGenerator::emitRestoreStackPointerFromFP() {
+  // This is used to restore the stack pointer after a call with a dynamic
+  // number of arguments.
+
+  MOZ_ASSERT(masm.framePushed() == frameSize());
+
+  int32_t offset = -int32_t(frameSize());
+  masm.computeEffectiveAddress(Address(FramePointer, offset),
+                               masm.getStackPointer());
+}
+
+void CodeGenerator::emitPushArguments(Register argcreg, Register scratch,
+                                      Register copyreg, uint32_t extraFormals) {
+  Label end;
+
+  // Skip the copy of arguments if there are none.
+  masm.branchTestPtr(Assembler::Zero, argcreg, argcreg, &end);
+
+  // clang-format off
+  //
+  // We are making a copy of the arguments which are above the JitFrameLayout
+  // of the current Ion frame.
+  //
+  // [arg1] [arg0] <- src [this] [JitFrameLayout] [.. frameSize ..] [pad] [arg1] [arg0] <- dst
+  //
+  // clang-format on
+
+  // Compute the source and destination offsets into the stack.
+  Register argvSrcBase = FramePointer;
+  size_t argvSrcOffset =
+      JitFrameLayout::offsetOfActualArgs() + extraFormals * sizeof(JS::Value);
+  size_t argvDstOffset = 0;
+
+  Register argvIndex = scratch;
+  masm.move32(argcreg, argvIndex);
+
+  // Copy arguments.
+  emitCopyValuesForApply(argvSrcBase, argvIndex, copyreg, argvSrcOffset,
+                         argvDstOffset);
+
+  // Join with all arguments copied and the extra stack usage computed.
+  masm.bind(&end);
+}
+
+void CodeGenerator::emitPushArguments(LApplyArgsGeneric* apply,
+                                      Register scratch) {
+  // Holds the function nargs. Initially the number of args to the caller.
+  Register argcreg = ToRegister(apply->getArgc());
+  Register copyreg = ToRegister(apply->getTempObject());
+  uint32_t extraFormals = apply->numExtraFormals();
+
+  emitAllocateSpaceForApply(argcreg, scratch);
+
+  emitPushArguments(argcreg, scratch, copyreg, extraFormals);
+
+  // Push |this|.
+  masm.pushValue(ToValue(apply, LApplyArgsGeneric::ThisIndex));
+}
+
+void CodeGenerator::emitPushArguments(LApplyArgsObj* apply, Register scratch) {
+  // argc and argsObj are mapped to the same calltemp register.
+  MOZ_ASSERT(apply->getArgsObj() == apply->getArgc());
+
+  Register tmpArgc = ToRegister(apply->getTempObject());
+  Register argsObj = ToRegister(apply->getArgsObj());
+
+  // Load argc into tmpArgc.
+  Address lengthAddr(argsObj, ArgumentsObject::getInitialLengthSlotOffset());
+  masm.unboxInt32(lengthAddr, tmpArgc);
+  masm.rshift32(Imm32(ArgumentsObject::PACKED_BITS_COUNT), tmpArgc);
+
+  // Allocate space on the stack for arguments. This modifies scratch.
+  emitAllocateSpaceForApply(tmpArgc, scratch);
+
+  // Load arguments data
+  masm.loadPrivate(Address(argsObj, ArgumentsObject::getDataSlotOffset()),
+                   argsObj);
+  size_t argsSrcOffset = ArgumentsData::offsetOfArgs();
+
+  // This is the end of the lifetime of argsObj.
+  // After this call, the argsObj register holds the argument count instead.
+  emitPushArrayAsArguments(tmpArgc, argsObj, scratch, argsSrcOffset);
+
+  masm.pushValue(ToValue(apply, LApplyArgsObj::ThisIndex));
+}
+
+void CodeGenerator::emitPushArrayAsArguments(Register tmpArgc,
+                                             Register srcBaseAndArgc,
+                                             Register scratch,
+                                             size_t argvSrcOffset) {
+  // Preconditions:
+  // 1. |tmpArgc| * sizeof(Value) bytes have been allocated at the top of
+  //    the stack to hold arguments.
+  // 2. |srcBaseAndArgc| + |srcOffset| points to an array of |tmpArgc| values.
+  //
+  // Postconditions:
+  // 1. The arguments at |srcBaseAndArgc| + |srcOffset| have been copied into
+  //    the allocated space.
+  // 2. |srcBaseAndArgc| now contains the original value of |tmpArgc|.
+  //
+  // |scratch| is used as a temp register within this function and clobbered.
+
+  Label noCopy, epilogue;
+
+  // Skip the copy of arguments if there are none.
+  masm.branchTestPtr(Assembler::Zero, tmpArgc, tmpArgc, &noCopy);
+
+  // Copy the values.  This code is skipped entirely if there are
+  // no values.
+  size_t argvDstOffset = 0;
+
+  Register argvSrcBase = srcBaseAndArgc;
+  Register copyreg = scratch;
+
+  masm.push(tmpArgc);
+  Register argvIndex = tmpArgc;
+  argvDstOffset += sizeof(void*);
+
+  // Copy
+  emitCopyValuesForApply(argvSrcBase, argvIndex, copyreg, argvSrcOffset,
+                         argvDstOffset);
+
+  // Restore.
+  masm.pop(srcBaseAndArgc);  // srcBaseAndArgc now contains argc.
+  masm.jump(&epilogue);
+
+  // Clear argc if we skipped the copy step.
+  masm.bind(&noCopy);
+  masm.movePtr(ImmWord(0), srcBaseAndArgc);
+
+  // Join with all arguments copied and the extra stack usage computed.
+  // Note, "srcBase" has become "argc".
+  masm.bind(&epilogue);
+}
+
+void CodeGenerator::emitPushArguments(LApplyArrayGeneric* apply,
+                                      Register scratch) {
+  Register tmpArgc = ToRegister(apply->getTempObject());
+  Register elementsAndArgc = ToRegister(apply->getElements());
+
+  // Invariants guarded in the caller:
+  //  - the array is not too long
+  //  - the array length equals its initialized length
+
+  // The array length is our argc for the purposes of allocating space.
+  Address length(ToRegister(apply->getElements()),
+                 ObjectElements::offsetOfLength());
+  masm.load32(length, tmpArgc);
+
+  // Allocate space for the values.
+  emitAllocateSpaceForApply(tmpArgc, scratch);
+
+  // After this call "elements" has become "argc".
+  size_t elementsOffset = 0;
+  emitPushArrayAsArguments(tmpArgc, elementsAndArgc, scratch, elementsOffset);
+
+  // Push |this|.
+  masm.pushValue(ToValue(apply, LApplyArrayGeneric::ThisIndex));
+}
+
+void CodeGenerator::emitPushArguments(LConstructArgsGeneric* construct,
+                                      Register scratch) {
+  MOZ_ASSERT(scratch == ToRegister(construct->getNewTarget()));
+
+  // Holds the function nargs. Initially the number of args to the caller.
+  Register argcreg = ToRegister(construct->getArgc());
+  Register copyreg = ToRegister(construct->getTempObject());
+  uint32_t extraFormals = construct->numExtraFormals();
+
+  // Allocate space for the values.
+  // After this call "newTarget" has become "scratch".
+  emitAllocateSpaceForConstructAndPushNewTarget(argcreg, scratch);
+
+  emitPushArguments(argcreg, scratch, copyreg, extraFormals);
+
+  // Push |this|.
+  masm.pushValue(ToValue(construct, LConstructArgsGeneric::ThisIndex));
+}
+
+void CodeGenerator::emitPushArguments(LConstructArrayGeneric* construct,
+                                      Register scratch) {
+  MOZ_ASSERT(scratch == ToRegister(construct->getNewTarget()));
+
+  Register tmpArgc = ToRegister(construct->getTempObject());
+  Register elementsAndArgc = ToRegister(construct->getElements());
+
+  // Invariants guarded in the caller:
+  //  - the array is not too long
+  //  - the array length equals its initialized length
+
+  // The array length is our argc for the purposes of allocating space.
+  Address length(ToRegister(construct->getElements()),
+                 ObjectElements::offsetOfLength());
+  masm.load32(length, tmpArgc);
+
+  // Allocate space for the values.
+  emitAllocateSpaceForConstructAndPushNewTarget(tmpArgc, scratch);
+
+  // After this call "elements" has become "argc" and "newTarget" has become
+  // "scratch".
+  size_t elementsOffset = 0;
+  emitPushArrayAsArguments(tmpArgc, elementsAndArgc, scratch, elementsOffset);
+
+  // Push |this|.
+  masm.pushValue(ToValue(construct, LConstructArrayGeneric::ThisIndex));
+}
+
+template <typename T>
+void CodeGenerator::emitApplyGeneric(T* apply) {
+  // Holds the function object.
+  Register calleereg = ToRegister(apply->getFunction());
+
+  // Temporary register for modifying the function object.
+  Register objreg = ToRegister(apply->getTempObject());
+  Register scratch = ToRegister(apply->getTempForArgCopy());
+
+  // Holds the function nargs, computed in the invoker or (for ApplyArray,
+  // ConstructArray, or ApplyArgsObj) in the argument pusher.
+  Register argcreg = ToRegister(apply->getArgc());
+
+  // Copy the arguments of the current function.
+  //
+  // In the case of ApplyArray, ConstructArray, or ApplyArgsObj, also
+  // compute argc. The argc register and the elements/argsObj register
+  // are the same; argc must not be referenced before the call to
+  // emitPushArguments() and elements/argsObj must not be referenced
+  // after it returns.
+  //
+  // In the case of ConstructArray or ConstructArgs, also overwrite newTarget
+  // with scratch; newTarget must not be referenced after this point.
+  //
+  // objreg is dead across this call.
+  emitPushArguments(apply, scratch);
+
+  masm.checkStackAlignment();
+
+  bool constructing = apply->mir()->isConstructing();
+
+  // If the function is native, only emit the call to InvokeFunction.
+  if (apply->hasSingleTarget() &&
+      apply->getSingleTarget()->isNativeWithoutJitEntry()) {
+    emitCallInvokeFunction(apply);
+
+#ifdef DEBUG
+    // Native constructors are guaranteed to return an Object value, so we never
+    // have to replace a primitive result with the previously allocated Object
+    // from CreateThis.
+    if (constructing) {
+      Label notPrimitive;
+      masm.branchTestPrimitive(Assembler::NotEqual, JSReturnOperand,
+                               &notPrimitive);
+      masm.assumeUnreachable("native constructors don't return primitives");
+      masm.bind(&notPrimitive);
+    }
+#endif
+
+    emitRestoreStackPointerFromFP();
+    return;
+  }
+
+  Label end, invoke;
+
+  // Unless already known, guard that calleereg is actually a function object.
+  if (!apply->hasSingleTarget()) {
+    masm.branchTestObjIsFunction(Assembler::NotEqual, calleereg, objreg,
+                                 calleereg, &invoke);
+  }
+
+  // Guard that calleereg is an interpreted function with a JSScript.
+  masm.branchIfFunctionHasNoJitEntry(calleereg, constructing, &invoke);
+
+  // Guard that callee allows the [[Call]] or [[Construct]] operation required.
+  if (constructing) {
+    masm.branchTestFunctionFlags(calleereg, FunctionFlags::CONSTRUCTOR,
+                                 Assembler::Zero, &invoke);
+  } else {
+    masm.branchFunctionKind(Assembler::Equal, FunctionFlags::ClassConstructor,
+                            calleereg, objreg, &invoke);
+  }
+
+  // Use the slow path if CreateThis was unable to create the |this| object.
+  if (constructing) {
+    Address thisAddr(masm.getStackPointer(), 0);
+    masm.branchTestNull(Assembler::Equal, thisAddr, &invoke);
+  }
+
+  // Call with an Ion frame or a rectifier frame.
+  {
+    if (apply->mir()->maybeCrossRealm()) {
+      masm.switchToObjectRealm(calleereg, objreg);
+    }
+
+    // Knowing that calleereg is a non-native function, load jitcode.
+    masm.loadJitCodeRaw(calleereg, objreg);
+
+    masm.PushCalleeToken(calleereg, constructing);
+    masm.PushFrameDescriptorForJitCall(FrameType::IonJS, argcreg, scratch);
+
+    Label underflow, rejoin;
+
+    // Check whether the provided arguments satisfy target argc.
+    if (!apply->hasSingleTarget()) {
+      Register nformals = scratch;
+      masm.loadFunctionArgCount(calleereg, nformals);
+      masm.branch32(Assembler::Below, argcreg, nformals, &underflow);
+    } else {
+      masm.branch32(Assembler::Below, argcreg,
+                    Imm32(apply->getSingleTarget()->nargs()), &underflow);
+    }
+
+    // Skip the construction of the rectifier frame because we have no
+    // underflow.
+    masm.jump(&rejoin);
+
+    // Argument fixup needed. Get ready to call the argumentsRectifier.
+    {
+      masm.bind(&underflow);
+
+      // Hardcode the address of the argumentsRectifier code.
+      TrampolinePtr argumentsRectifier =
+          gen->jitRuntime()->getArgumentsRectifier();
+      masm.movePtr(argumentsRectifier, objreg);
+    }
+
+    masm.bind(&rejoin);
+
+    // Finally call the function in objreg, as assigned by one of the paths
+    // above.
+    ensureOsiSpace();
+    uint32_t callOffset = masm.callJit(objreg);
+    markSafepointAt(callOffset, apply);
+
+    if (apply->mir()->maybeCrossRealm()) {
+      static_assert(!JSReturnOperand.aliases(ReturnReg),
+                    "ReturnReg available as scratch after scripted calls");
+      masm.switchToRealm(gen->realm->realmPtr(), ReturnReg);
+    }
+
+    // Discard JitFrameLayout fields still left on the stack.
+    masm.freeStack(sizeof(JitFrameLayout) -
+                   JitFrameLayout::bytesPoppedAfterCall());
+    masm.jump(&end);
+  }
+
+  // Handle uncompiled or native functions.
+  {
+    masm.bind(&invoke);
+    emitCallInvokeFunction(apply);
+  }
+
+  masm.bind(&end);
+
+  // If the return value of the constructing function is Primitive,
+  // replace the return value with the Object from CreateThis.
+  if (constructing) {
+    Label notPrimitive;
+    masm.branchTestPrimitive(Assembler::NotEqual, JSReturnOperand,
+                             &notPrimitive);
+    masm.loadValue(Address(masm.getStackPointer(), 0), JSReturnOperand);
+
+#ifdef DEBUG
+    masm.branchTestPrimitive(Assembler::NotEqual, JSReturnOperand,
+                             &notPrimitive);
+    masm.assumeUnreachable("CreateThis creates an object");
+#endif
+
+    masm.bind(&notPrimitive);
+  }
+
+  // Pop arguments and continue.
+  emitRestoreStackPointerFromFP();
+}
+
+void CodeGenerator::visitApplyArgsGeneric(LApplyArgsGeneric* apply) {
+  LSnapshot* snapshot = apply->snapshot();
+  Register argcreg = ToRegister(apply->getArgc());
+
+  // Ensure that we have a reasonable number of arguments.
+  bailoutCmp32(Assembler::Above, argcreg, Imm32(JIT_ARGS_LENGTH_MAX), snapshot);
+
+  emitApplyGeneric(apply);
+}
+
+void CodeGenerator::visitApplyArgsObj(LApplyArgsObj* apply) {
+  Register argsObj = ToRegister(apply->getArgsObj());
+  Register temp = ToRegister(apply->getTempObject());
+
+  Label bail;
+  masm.loadArgumentsObjectLength(argsObj, temp, &bail);
+  masm.branch32(Assembler::Above, temp, Imm32(JIT_ARGS_LENGTH_MAX), &bail);
+  bailoutFrom(&bail, apply->snapshot());
+
+  emitApplyGeneric(apply);
+}
+
+void CodeGenerator::visitApplyArrayGeneric(LApplyArrayGeneric* apply) {
+  LSnapshot* snapshot = apply->snapshot();
+  Register tmp = ToRegister(apply->getTempObject());
+
+  Address length(ToRegister(apply->getElements()),
+                 ObjectElements::offsetOfLength());
+  masm.load32(length, tmp);
+
+  // Ensure that we have a reasonable number of arguments.
+  bailoutCmp32(Assembler::Above, tmp, Imm32(JIT_ARGS_LENGTH_MAX), snapshot);
+
+  // Ensure that the array does not contain an uninitialized tail.
+
+  Address initializedLength(ToRegister(apply->getElements()),
+                            ObjectElements::offsetOfInitializedLength());
+  masm.sub32(initializedLength, tmp);
+  bailoutCmp32(Assembler::NotEqual, tmp, Imm32(0), snapshot);
+
+  emitApplyGeneric(apply);
+}
+
+void CodeGenerator::visitConstructArgsGeneric(LConstructArgsGeneric* lir) {
+  LSnapshot* snapshot = lir->snapshot();
+  Register argcreg = ToRegister(lir->getArgc());
+
+  // Ensure that we have a reasonable number of arguments.
+  bailoutCmp32(Assembler::Above, argcreg, Imm32(JIT_ARGS_LENGTH_MAX), snapshot);
+
+  emitApplyGeneric(lir);
+}
+
+void CodeGenerator::visitConstructArrayGeneric(LConstructArrayGeneric* lir) {
+  LSnapshot* snapshot = lir->snapshot();
+  Register tmp = ToRegister(lir->getTempObject());
+
+  Address length(ToRegister(lir->getElements()),
+                 ObjectElements::offsetOfLength());
+  masm.load32(length, tmp);
+
+  // Ensure that we have a reasonable number of arguments.
+  bailoutCmp32(Assembler::Above, tmp, Imm32(JIT_ARGS_LENGTH_MAX), snapshot);
+
+  // Ensure that the array does not contain an uninitialized tail.
+
+  Address initializedLength(ToRegister(lir->getElements()),
+                            ObjectElements::offsetOfInitializedLength());
+  masm.sub32(initializedLength, tmp);
+  bailoutCmp32(Assembler::NotEqual, tmp, Imm32(0), snapshot);
+
+  emitApplyGeneric(lir);
+}
+
+void CodeGenerator::visitBail(LBail* lir) { bailout(lir->snapshot()); }
+
+void CodeGenerator::visitUnreachable(LUnreachable* lir) {
+  masm.assumeUnreachable("end-of-block assumed unreachable");
+}
+
+void CodeGenerator::visitEncodeSnapshot(LEncodeSnapshot* lir) {
+  encode(lir->snapshot());
+}
+
+void CodeGenerator::visitUnreachableResultV(LUnreachableResultV* lir) {
+  masm.assumeUnreachable("must be unreachable");
+}
+
+void CodeGenerator::visitUnreachableResultT(LUnreachableResultT* lir) {
+  masm.assumeUnreachable("must be unreachable");
+}
+
+// Out-of-line path to report over-recursed error and fail.
+class CheckOverRecursedFailure : public OutOfLineCodeBase<CodeGenerator> {
+  LInstruction* lir_;
+
+ public:
+  explicit CheckOverRecursedFailure(LInstruction* lir) : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitCheckOverRecursedFailure(this);
+  }
+
+  LInstruction* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitCheckOverRecursed(LCheckOverRecursed* lir) {
+  // If we don't push anything on the stack, skip the check.
+  if (omitOverRecursedCheck()) {
+    return;
+  }
+
+  // Ensure that this frame will not cross the stack limit.
+  // This is a weak check, justified by Ion using the C stack: we must always
+  // be some distance away from the actual limit, since if the limit is
+  // crossed, an error must be thrown, which requires more frames.
+  //
+  // It must always be possible to trespass past the stack limit.
+  // Ion may legally place frames very close to the limit. Calling additional
+  // C functions may then violate the limit without any checking.
+  //
+  // Since Ion frames exist on the C stack, the stack limit may be
+  // dynamically set by JS_SetThreadStackLimit() and JS_SetNativeStackQuota().
+
+  CheckOverRecursedFailure* ool = new (alloc()) CheckOverRecursedFailure(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  // Conditional forward (unlikely) branch to failure.
+  const void* limitAddr = gen->runtime->addressOfJitStackLimit();
+  masm.branchStackPtrRhs(Assembler::AboveOrEqual, AbsoluteAddress(limitAddr),
+                         ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCheckOverRecursedFailure(
+    CheckOverRecursedFailure* ool) {
+  // The OOL path is hit if the recursion depth has been exceeded.
+  // Throw an InternalError for over-recursion.
+
+  // LFunctionEnvironment can appear before LCheckOverRecursed, so we have
+  // to save all live registers to avoid crashes if CheckOverRecursed triggers
+  // a GC.
+  saveLive(ool->lir());
+
+  using Fn = bool (*)(JSContext*);
+  callVM<Fn, CheckOverRecursed>(ool->lir());
+
+  restoreLive(ool->lir());
+  masm.jump(ool->rejoin());
+}
+
+IonScriptCounts* CodeGenerator::maybeCreateScriptCounts() {
+  // If scripts are being profiled, create a new IonScriptCounts for the
+  // profiling data, which will be attached to the associated JSScript or
+  // wasm module after code generation finishes.
+  if (!gen->hasProfilingScripts()) {
+    return nullptr;
+  }
+
+  // This test inhibits IonScriptCount creation for wasm code which is
+  // currently incompatible with wasm codegen for two reasons: (1) wasm code
+  // must be serializable and script count codegen bakes in absolute
+  // addresses, (2) wasm code does not have a JSScript with which to associate
+  // code coverage data.
+  JSScript* script = gen->outerInfo().script();
+  if (!script) {
+    return nullptr;
+  }
+
+  auto counts = MakeUnique<IonScriptCounts>();
+  if (!counts || !counts->init(graph.numBlocks())) {
+    return nullptr;
+  }
+
+  for (size_t i = 0; i < graph.numBlocks(); i++) {
+    MBasicBlock* block = graph.getBlock(i)->mir();
+
+    uint32_t offset = 0;
+    char* description = nullptr;
+    if (MResumePoint* resume = block->entryResumePoint()) {
+      // Find a PC offset in the outermost script to use. If this
+      // block is from an inlined script, find a location in the
+      // outer script to associate information about the inlining
+      // with.
+      while (resume->caller()) {
+        resume = resume->caller();
+      }
+      offset = script->pcToOffset(resume->pc());
+
+      if (block->entryResumePoint()->caller()) {
+        // Get the filename and line number of the inner script.
+        JSScript* innerScript = block->info().script();
+        description = js_pod_calloc<char>(200);
+        if (description) {
+          snprintf(description, 200, "%s:%u", innerScript->filename(),
+                   innerScript->lineno());
+        }
+      }
+    }
+
+    if (!counts->block(i).init(block->id(), offset, description,
+                               block->numSuccessors())) {
+      return nullptr;
+    }
+
+    for (size_t j = 0; j < block->numSuccessors(); j++) {
+      counts->block(i).setSuccessor(
+          j, skipTrivialBlocks(block->getSuccessor(j))->id());
+    }
+  }
+
+  scriptCounts_ = counts.release();
+  return scriptCounts_;
+}
+
+// Structure for managing the state tracked for a block by script counters.
+struct ScriptCountBlockState {
+  IonBlockCounts& block;
+  MacroAssembler& masm;
+
+  Sprinter printer;
+
+ public:
+  ScriptCountBlockState(IonBlockCounts* block, MacroAssembler* masm)
+      : block(*block), masm(*masm), printer(GetJitContext()->cx, false) {}
+
+  bool init() {
+    if (!printer.init()) {
+      return false;
+    }
+
+    // Bump the hit count for the block at the start. This code is not
+    // included in either the text for the block or the instruction byte
+    // counts.
+    masm.inc64(AbsoluteAddress(block.addressOfHitCount()));
+
+    // Collect human readable assembly for the code generated in the block.
+    masm.setPrinter(&printer);
+
+    return true;
+  }
+
+  void visitInstruction(LInstruction* ins) {
+#ifdef JS_JITSPEW
+    // Prefix stream of assembly instructions with their LIR instruction
+    // name and any associated high level info.
+    if (const char* extra = ins->getExtraName()) {
+      printer.printf("[%s:%s]\n", ins->opName(), extra);
+    } else {
+      printer.printf("[%s]\n", ins->opName());
+    }
+#endif
+  }
+
+  ~ScriptCountBlockState() {
+    masm.setPrinter(nullptr);
+
+    if (!printer.hadOutOfMemory()) {
+      block.setCode(printer.string());
+    }
+  }
+};
+
+void CodeGenerator::branchIfInvalidated(Register temp, Label* invalidated) {
+  CodeOffset label = masm.movWithPatch(ImmWord(uintptr_t(-1)), temp);
+  masm.propagateOOM(ionScriptLabels_.append(label));
+
+  // If IonScript::invalidationCount_ != 0, the script has been invalidated.
+  masm.branch32(Assembler::NotEqual,
+                Address(temp, IonScript::offsetOfInvalidationCount()), Imm32(0),
+                invalidated);
+}
+
+#ifdef DEBUG
+void CodeGenerator::emitAssertGCThingResult(Register input,
+                                            const MDefinition* mir) {
+  MIRType type = mir->type();
+  MOZ_ASSERT(type == MIRType::Object || type == MIRType::String ||
+             type == MIRType::Symbol || type == MIRType::BigInt);
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+  regs.take(input);
+
+  Register temp = regs.takeAny();
+  masm.push(temp);
+
+  // Don't check if the script has been invalidated. In that case invalid
+  // types are expected (until we reach the OsiPoint and bailout).
+  Label done;
+  branchIfInvalidated(temp, &done);
+
+#  ifndef JS_SIMULATOR
+  // Check that we have a valid GC pointer.
+  // Disable for wasm because we don't have a context on wasm compilation
+  // threads and this needs a context.
+  // Also disable for simulator builds because the C++ call is a lot slower
+  // there than on actual hardware.
+  if (JitOptions.fullDebugChecks && !IsCompilingWasm()) {
+    saveVolatile();
+    masm.setupUnalignedABICall(temp);
+    masm.loadJSContext(temp);
+    masm.passABIArg(temp);
+    masm.passABIArg(input);
+
+    switch (type) {
+      case MIRType::Object: {
+        using Fn = void (*)(JSContext* cx, JSObject* obj);
+        masm.callWithABI<Fn, AssertValidObjectPtr>();
+        break;
+      }
+      case MIRType::String: {
+        using Fn = void (*)(JSContext* cx, JSString* str);
+        masm.callWithABI<Fn, AssertValidStringPtr>();
+        break;
+      }
+      case MIRType::Symbol: {
+        using Fn = void (*)(JSContext* cx, JS::Symbol* sym);
+        masm.callWithABI<Fn, AssertValidSymbolPtr>();
+        break;
+      }
+      case MIRType::BigInt: {
+        using Fn = void (*)(JSContext* cx, JS::BigInt* bi);
+        masm.callWithABI<Fn, AssertValidBigIntPtr>();
+        break;
+      }
+      default:
+        MOZ_CRASH();
+    }
+
+    restoreVolatile();
+  }
+#  endif
+
+  masm.bind(&done);
+  masm.pop(temp);
+}
+
+void CodeGenerator::emitAssertResultV(const ValueOperand input,
+                                      const MDefinition* mir) {
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+  regs.take(input);
+
+  Register temp1 = regs.takeAny();
+  Register temp2 = regs.takeAny();
+  masm.push(temp1);
+  masm.push(temp2);
+
+  // Don't check if the script has been invalidated. In that case invalid
+  // types are expected (until we reach the OsiPoint and bailout).
+  Label done;
+  branchIfInvalidated(temp1, &done);
+
+  // Check that we have a valid GC pointer.
+  if (JitOptions.fullDebugChecks) {
+    saveVolatile();
+
+    masm.pushValue(input);
+    masm.moveStackPtrTo(temp1);
+
+    using Fn = void (*)(JSContext* cx, Value* v);
+    masm.setupUnalignedABICall(temp2);
+    masm.loadJSContext(temp2);
+    masm.passABIArg(temp2);
+    masm.passABIArg(temp1);
+    masm.callWithABI<Fn, AssertValidValue>();
+    masm.popValue(input);
+    restoreVolatile();
+  }
+
+  masm.bind(&done);
+  masm.pop(temp2);
+  masm.pop(temp1);
+}
+
+void CodeGenerator::emitGCThingResultChecks(LInstruction* lir,
+                                            MDefinition* mir) {
+  if (lir->numDefs() == 0) {
+    return;
+  }
+
+  MOZ_ASSERT(lir->numDefs() == 1);
+  if (lir->getDef(0)->isBogusTemp()) {
+    return;
+  }
+
+  Register output = ToRegister(lir->getDef(0));
+  emitAssertGCThingResult(output, mir);
+}
+
+void CodeGenerator::emitValueResultChecks(LInstruction* lir, MDefinition* mir) {
+  if (lir->numDefs() == 0) {
+    return;
+  }
+
+  MOZ_ASSERT(lir->numDefs() == BOX_PIECES);
+  if (!lir->getDef(0)->output()->isRegister()) {
+    return;
+  }
+
+  ValueOperand output = ToOutValue(lir);
+
+  emitAssertResultV(output, mir);
+}
+
+void CodeGenerator::emitDebugResultChecks(LInstruction* ins) {
+  // In debug builds, check that LIR instructions return valid values.
+
+  MDefinition* mir = ins->mirRaw();
+  if (!mir) {
+    return;
+  }
+
+  switch (mir->type()) {
+    case MIRType::Object:
+    case MIRType::String:
+    case MIRType::Symbol:
+    case MIRType::BigInt:
+      emitGCThingResultChecks(ins, mir);
+      break;
+    case MIRType::Value:
+      emitValueResultChecks(ins, mir);
+      break;
+    default:
+      break;
+  }
+}
+
+void CodeGenerator::emitDebugForceBailing(LInstruction* lir) {
+  if (MOZ_LIKELY(!gen->options.ionBailAfterEnabled())) {
+    return;
+  }
+  if (!lir->snapshot()) {
+    return;
+  }
+  if (lir->isOsiPoint()) {
+    return;
+  }
+
+  masm.comment("emitDebugForceBailing");
+  const void* bailAfterCounterAddr =
+      gen->runtime->addressOfIonBailAfterCounter();
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+
+  Label done, notBail;
+  masm.branch32(Assembler::Equal, AbsoluteAddress(bailAfterCounterAddr),
+                Imm32(0), &done);
+  {
+    Register temp = regs.takeAny();
+
+    masm.push(temp);
+    masm.load32(AbsoluteAddress(bailAfterCounterAddr), temp);
+    masm.sub32(Imm32(1), temp);
+    masm.store32(temp, AbsoluteAddress(bailAfterCounterAddr));
+
+    masm.branch32(Assembler::NotEqual, temp, Imm32(0), &notBail);
+    {
+      masm.pop(temp);
+      bailout(lir->snapshot());
+    }
+    masm.bind(&notBail);
+    masm.pop(temp);
+  }
+  masm.bind(&done);
+}
+#endif
+
+bool CodeGenerator::generateBody() {
+  JitSpewCont(JitSpew_Codegen, "\n");
+  AutoCreatedBy acb(masm, "CodeGenerator::generateBody");
+
+  JitSpew(JitSpew_Codegen, "==== BEGIN CodeGenerator::generateBody ====");
+  IonScriptCounts* counts = maybeCreateScriptCounts();
+
+  const bool compilingWasm = gen->compilingWasm();
+
+  for (size_t i = 0; i < graph.numBlocks(); i++) {
+    current = graph.getBlock(i);
+
+    // Don't emit any code for trivial blocks, containing just a goto. Such
+    // blocks are created to split critical edges, and if we didn't end up
+    // putting any instructions in them, we can skip them.
+    if (current->isTrivial()) {
+      continue;
+    }
+
+#ifdef JS_JITSPEW
+    const char* filename = nullptr;
+    size_t lineNumber = 0;
+    unsigned columnNumber = 0;
+    if (current->mir()->info().script()) {
+      filename = current->mir()->info().script()->filename();
+      if (current->mir()->pc()) {
+        lineNumber = PCToLineNumber(current->mir()->info().script(),
+                                    current->mir()->pc(), &columnNumber);
+      }
+    } else {
+#  ifdef DEBUG
+      lineNumber = current->mir()->lineno();
+      columnNumber = current->mir()->columnIndex();
+#  endif
+    }
+    JitSpew(JitSpew_Codegen, "--------------------------------");
+    JitSpew(JitSpew_Codegen, "# block%zu %s:%zu:%u%s:", i,
+            filename ? filename : "?", lineNumber, columnNumber,
+            current->mir()->isLoopHeader() ? " (loop header)" : "");
+#endif
+
+    if (current->mir()->isLoopHeader() && compilingWasm) {
+      masm.nopAlign(CodeAlignment);
+    }
+
+    masm.bind(current->label());
+
+    mozilla::Maybe<ScriptCountBlockState> blockCounts;
+    if (counts) {
+      blockCounts.emplace(&counts->block(i), &masm);
+      if (!blockCounts->init()) {
+        return false;
+      }
+    }
+
+    for (LInstructionIterator iter = current->begin(); iter != current->end();
+         iter++) {
+      if (!alloc().ensureBallast()) {
+        return false;
+      }
+
+      perfSpewer_.recordInstruction(masm, *iter);
+#ifdef JS_JITSPEW
+      JitSpewStart(JitSpew_Codegen, "                                # LIR=%s",
+                   iter->opName());
+      if (const char* extra = iter->getExtraName()) {
+        JitSpewCont(JitSpew_Codegen, ":%s", extra);
+      }
+      JitSpewFin(JitSpew_Codegen);
+#endif
+
+      if (counts) {
+        blockCounts->visitInstruction(*iter);
+      }
+
+#ifdef CHECK_OSIPOINT_REGISTERS
+      if (iter->safepoint() && !compilingWasm) {
+        resetOsiPointRegs(iter->safepoint());
+      }
+#endif
+
+      if (!compilingWasm) {
+        if (MDefinition* mir = iter->mirRaw()) {
+          if (!addNativeToBytecodeEntry(mir->trackedSite())) {
+            return false;
+          }
+        }
+      }
+
+      setElement(*iter);  // needed to encode correct snapshot location.
+
+#ifdef DEBUG
+      emitDebugForceBailing(*iter);
+#endif
+
+      switch (iter->op()) {
+#ifndef JS_CODEGEN_NONE
+#  define LIROP(op)              \
+    case LNode::Opcode::op:      \
+      visit##op(iter->to##op()); \
+      break;
+        LIR_OPCODE_LIST(LIROP)
+#  undef LIROP
+#endif
+        case LNode::Opcode::Invalid:
+        default:
+          MOZ_CRASH("Invalid LIR op");
+      }
+
+#ifdef DEBUG
+      if (!counts) {
+        emitDebugResultChecks(*iter);
+      }
+#endif
+    }
+    if (masm.oom()) {
+      return false;
+    }
+  }
+
+  JitSpew(JitSpew_Codegen, "==== END CodeGenerator::generateBody ====\n");
+  return true;
+}
+
+// Out-of-line object allocation for LNewArray.
+class OutOfLineNewArray : public OutOfLineCodeBase<CodeGenerator> {
+  LNewArray* lir_;
+
+ public:
+  explicit OutOfLineNewArray(LNewArray* lir) : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineNewArray(this);
+  }
+
+  LNewArray* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitNewArrayCallVM(LNewArray* lir) {
+  Register objReg = ToRegister(lir->output());
+
+  MOZ_ASSERT(!lir->isCall());
+  saveLive(lir);
+
+  JSObject* templateObject = lir->mir()->templateObject();
+
+  if (templateObject) {
+    pushArg(ImmGCPtr(templateObject->shape()));
+    pushArg(Imm32(lir->mir()->length()));
+
+    using Fn = ArrayObject* (*)(JSContext*, uint32_t, Handle<Shape*>);
+    callVM<Fn, NewArrayWithShape>(lir);
+  } else {
+    pushArg(Imm32(GenericObject));
+    pushArg(Imm32(lir->mir()->length()));
+
+    using Fn = ArrayObject* (*)(JSContext*, uint32_t, NewObjectKind);
+    callVM<Fn, NewArrayOperation>(lir);
+  }
+
+  masm.storeCallPointerResult(objReg);
+
+  MOZ_ASSERT(!lir->safepoint()->liveRegs().has(objReg));
+  restoreLive(lir);
+}
+
+void CodeGenerator::visitAtan2D(LAtan2D* lir) {
+  FloatRegister y = ToFloatRegister(lir->y());
+  FloatRegister x = ToFloatRegister(lir->x());
+
+  using Fn = double (*)(double x, double y);
+  masm.setupAlignedABICall();
+  masm.passABIArg(y, MoveOp::DOUBLE);
+  masm.passABIArg(x, MoveOp::DOUBLE);
+  masm.callWithABI<Fn, ecmaAtan2>(MoveOp::DOUBLE);
+
+  MOZ_ASSERT(ToFloatRegister(lir->output()) == ReturnDoubleReg);
+}
+
+void CodeGenerator::visitHypot(LHypot* lir) {
+  uint32_t numArgs = lir->numArgs();
+  masm.setupAlignedABICall();
+
+  for (uint32_t i = 0; i < numArgs; ++i) {
+    masm.passABIArg(ToFloatRegister(lir->getOperand(i)), MoveOp::DOUBLE);
+  }
+
+  switch (numArgs) {
+    case 2: {
+      using Fn = double (*)(double x, double y);
+      masm.callWithABI<Fn, ecmaHypot>(MoveOp::DOUBLE);
+      break;
+    }
+    case 3: {
+      using Fn = double (*)(double x, double y, double z);
+      masm.callWithABI<Fn, hypot3>(MoveOp::DOUBLE);
+      break;
+    }
+    case 4: {
+      using Fn = double (*)(double x, double y, double z, double w);
+      masm.callWithABI<Fn, hypot4>(MoveOp::DOUBLE);
+      break;
+    }
+    default:
+      MOZ_CRASH("Unexpected number of arguments to hypot function.");
+  }
+  MOZ_ASSERT(ToFloatRegister(lir->output()) == ReturnDoubleReg);
+}
+
+void CodeGenerator::visitNewArray(LNewArray* lir) {
+  Register objReg = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp());
+  DebugOnly<uint32_t> length = lir->mir()->length();
+
+  MOZ_ASSERT(length <= NativeObject::MAX_DENSE_ELEMENTS_COUNT);
+
+  if (lir->mir()->isVMCall()) {
+    visitNewArrayCallVM(lir);
+    return;
+  }
+
+  OutOfLineNewArray* ool = new (alloc()) OutOfLineNewArray(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  TemplateObject templateObject(lir->mir()->templateObject());
+#ifdef DEBUG
+  size_t numInlineElements = gc::GetGCKindSlots(templateObject.getAllocKind()) -
+                             ObjectElements::VALUES_PER_HEADER;
+  MOZ_ASSERT(length <= numInlineElements,
+             "Inline allocation only supports inline elements");
+#endif
+  masm.createGCObject(objReg, tempReg, templateObject,
+                      lir->mir()->initialHeap(), ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineNewArray(OutOfLineNewArray* ool) {
+  visitNewArrayCallVM(ool->lir());
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitNewArrayDynamicLength(LNewArrayDynamicLength* lir) {
+  Register lengthReg = ToRegister(lir->length());
+  Register objReg = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp0());
+
+  JSObject* templateObject = lir->mir()->templateObject();
+  gc::Heap initialHeap = lir->mir()->initialHeap();
+
+  using Fn = ArrayObject* (*)(JSContext*, Handle<ArrayObject*>, int32_t length);
+  OutOfLineCode* ool = oolCallVM<Fn, ArrayConstructorOneArg>(
+      lir, ArgList(ImmGCPtr(templateObject), lengthReg),
+      StoreRegisterTo(objReg));
+
+  bool canInline = true;
+  size_t inlineLength = 0;
+  if (templateObject->as<ArrayObject>().hasFixedElements()) {
+    size_t numSlots =
+        gc::GetGCKindSlots(templateObject->asTenured().getAllocKind());
+    inlineLength = numSlots - ObjectElements::VALUES_PER_HEADER;
+  } else {
+    canInline = false;
+  }
+
+  if (canInline) {
+    // Try to do the allocation inline if the template object is big enough
+    // for the length in lengthReg. If the length is bigger we could still
+    // use the template object and not allocate the elements, but it's more
+    // efficient to do a single big allocation than (repeatedly) reallocating
+    // the array later on when filling it.
+    masm.branch32(Assembler::Above, lengthReg, Imm32(inlineLength),
+                  ool->entry());
+
+    TemplateObject templateObj(templateObject);
+    masm.createGCObject(objReg, tempReg, templateObj, initialHeap,
+                        ool->entry());
+
+    size_t lengthOffset = NativeObject::offsetOfFixedElements() +
+                          ObjectElements::offsetOfLength();
+    masm.store32(lengthReg, Address(objReg, lengthOffset));
+  } else {
+    masm.jump(ool->entry());
+  }
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewIterator(LNewIterator* lir) {
+  Register objReg = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp0());
+
+  OutOfLineCode* ool;
+  switch (lir->mir()->type()) {
+    case MNewIterator::ArrayIterator: {
+      using Fn = ArrayIteratorObject* (*)(JSContext*);
+      ool = oolCallVM<Fn, NewArrayIterator>(lir, ArgList(),
+                                            StoreRegisterTo(objReg));
+      break;
+    }
+    case MNewIterator::StringIterator: {
+      using Fn = StringIteratorObject* (*)(JSContext*);
+      ool = oolCallVM<Fn, NewStringIterator>(lir, ArgList(),
+                                             StoreRegisterTo(objReg));
+      break;
+    }
+    case MNewIterator::RegExpStringIterator: {
+      using Fn = RegExpStringIteratorObject* (*)(JSContext*);
+      ool = oolCallVM<Fn, NewRegExpStringIterator>(lir, ArgList(),
+                                                   StoreRegisterTo(objReg));
+      break;
+    }
+    default:
+      MOZ_CRASH("unexpected iterator type");
+  }
+
+  TemplateObject templateObject(lir->mir()->templateObject());
+  masm.createGCObject(objReg, tempReg, templateObject, gc::Heap::Default,
+                      ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewTypedArray(LNewTypedArray* lir) {
+  Register objReg = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp0());
+  Register lengthReg = ToRegister(lir->temp1());
+  LiveRegisterSet liveRegs = liveVolatileRegs(lir);
+
+  JSObject* templateObject = lir->mir()->templateObject();
+  gc::Heap initialHeap = lir->mir()->initialHeap();
+
+  TypedArrayObject* ttemplate = &templateObject->as<TypedArrayObject>();
+
+  size_t n = ttemplate->length();
+  MOZ_ASSERT(n <= INT32_MAX,
+             "Template objects are only created for int32 lengths");
+
+  using Fn = TypedArrayObject* (*)(JSContext*, HandleObject, int32_t length);
+  OutOfLineCode* ool = oolCallVM<Fn, NewTypedArrayWithTemplateAndLength>(
+      lir, ArgList(ImmGCPtr(templateObject), Imm32(n)),
+      StoreRegisterTo(objReg));
+
+  TemplateObject templateObj(templateObject);
+  masm.createGCObject(objReg, tempReg, templateObj, initialHeap, ool->entry());
+
+  masm.initTypedArraySlots(objReg, tempReg, lengthReg, liveRegs, ool->entry(),
+                           ttemplate, MacroAssembler::TypedArrayLength::Fixed);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewTypedArrayDynamicLength(
+    LNewTypedArrayDynamicLength* lir) {
+  Register lengthReg = ToRegister(lir->length());
+  Register objReg = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp0());
+  LiveRegisterSet liveRegs = liveVolatileRegs(lir);
+
+  JSObject* templateObject = lir->mir()->templateObject();
+  gc::Heap initialHeap = lir->mir()->initialHeap();
+
+  TypedArrayObject* ttemplate = &templateObject->as<TypedArrayObject>();
+
+  using Fn = TypedArrayObject* (*)(JSContext*, HandleObject, int32_t length);
+  OutOfLineCode* ool = oolCallVM<Fn, NewTypedArrayWithTemplateAndLength>(
+      lir, ArgList(ImmGCPtr(templateObject), lengthReg),
+      StoreRegisterTo(objReg));
+
+  // Volatile |lengthReg| is saved across the ABI call in |initTypedArraySlots|.
+  MOZ_ASSERT_IF(lengthReg.volatile_(), liveRegs.has(lengthReg));
+
+  TemplateObject templateObj(templateObject);
+  masm.createGCObject(objReg, tempReg, templateObj, initialHeap, ool->entry());
+
+  masm.initTypedArraySlots(objReg, tempReg, lengthReg, liveRegs, ool->entry(),
+                           ttemplate,
+                           MacroAssembler::TypedArrayLength::Dynamic);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewTypedArrayFromArray(LNewTypedArrayFromArray* lir) {
+  pushArg(ToRegister(lir->array()));
+  pushArg(ImmGCPtr(lir->mir()->templateObject()));
+
+  using Fn = TypedArrayObject* (*)(JSContext*, HandleObject, HandleObject);
+  callVM<Fn, js::NewTypedArrayWithTemplateAndArray>(lir);
+}
+
+void CodeGenerator::visitNewTypedArrayFromArrayBuffer(
+    LNewTypedArrayFromArrayBuffer* lir) {
+  pushArg(ToValue(lir, LNewTypedArrayFromArrayBuffer::LengthIndex));
+  pushArg(ToValue(lir, LNewTypedArrayFromArrayBuffer::ByteOffsetIndex));
+  pushArg(ToRegister(lir->arrayBuffer()));
+  pushArg(ImmGCPtr(lir->mir()->templateObject()));
+
+  using Fn = TypedArrayObject* (*)(JSContext*, HandleObject, HandleObject,
+                                   HandleValue, HandleValue);
+  callVM<Fn, js::NewTypedArrayWithTemplateAndBuffer>(lir);
+}
+
+void CodeGenerator::visitBindFunction(LBindFunction* lir) {
+  Register target = ToRegister(lir->target());
+  Register temp1 = ToRegister(lir->temp0());
+  Register temp2 = ToRegister(lir->temp1());
+
+  // Try to allocate a new BoundFunctionObject we can pass to the VM function.
+  // If this fails, we set temp1 to nullptr so we do the allocation in C++.
+  TemplateObject templateObject(lir->mir()->templateObject());
+  Label allocOk, allocFailed;
+  masm.createGCObject(temp1, temp2, templateObject, gc::Heap::Default,
+                      &allocFailed);
+  masm.jump(&allocOk);
+
+  masm.bind(&allocFailed);
+  masm.movePtr(ImmWord(0), temp1);
+
+  masm.bind(&allocOk);
+
+  // Set temp2 to the address of the first argument on the stack.
+  // Note that the Value slots used for arguments are currently aligned for a
+  // JIT call, even though that's not strictly necessary for calling into C++.
+  uint32_t argc = lir->mir()->numStackArgs();
+  if (JitStackValueAlignment > 1) {
+    argc = AlignBytes(argc, JitStackValueAlignment);
+  }
+  uint32_t unusedStack = UnusedStackBytesForCall(argc);
+  masm.computeEffectiveAddress(Address(masm.getStackPointer(), unusedStack),
+                               temp2);
+
+  pushArg(temp1);
+  pushArg(Imm32(lir->mir()->numStackArgs()));
+  pushArg(temp2);
+  pushArg(target);
+
+  using Fn = BoundFunctionObject* (*)(JSContext*, Handle<JSObject*>, Value*,
+                                      uint32_t, Handle<BoundFunctionObject*>);
+  callVM<Fn, js::BoundFunctionObject::functionBindImpl>(lir);
+}
+
+void CodeGenerator::visitNewBoundFunction(LNewBoundFunction* lir) {
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  JSObject* templateObj = lir->mir()->templateObj();
+
+  using Fn = BoundFunctionObject* (*)(JSContext*, Handle<BoundFunctionObject*>);
+  OutOfLineCode* ool = oolCallVM<Fn, BoundFunctionObject::createWithTemplate>(
+      lir, ArgList(ImmGCPtr(templateObj)), StoreRegisterTo(output));
+
+  TemplateObject templateObject(templateObj);
+  masm.createGCObject(output, temp, templateObject, gc::Heap::Default,
+                      ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+// Out-of-line object allocation for JSOp::NewObject.
+class OutOfLineNewObject : public OutOfLineCodeBase<CodeGenerator> {
+  LNewObject* lir_;
+
+ public:
+  explicit OutOfLineNewObject(LNewObject* lir) : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineNewObject(this);
+  }
+
+  LNewObject* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitNewObjectVMCall(LNewObject* lir) {
+  Register objReg = ToRegister(lir->output());
+
+  MOZ_ASSERT(!lir->isCall());
+  saveLive(lir);
+
+  JSObject* templateObject = lir->mir()->templateObject();
+
+  // If we're making a new object with a class prototype (that is, an object
+  // that derives its class from its prototype instead of being
+  // PlainObject::class_'d) from self-hosted code, we need a different init
+  // function.
+  switch (lir->mir()->mode()) {
+    case MNewObject::ObjectLiteral: {
+      MOZ_ASSERT(!templateObject);
+      pushArg(ImmPtr(lir->mir()->resumePoint()->pc()));
+      pushArg(ImmGCPtr(lir->mir()->block()->info().script()));
+
+      using Fn = JSObject* (*)(JSContext*, HandleScript, const jsbytecode* pc);
+      callVM<Fn, NewObjectOperation>(lir);
+      break;
+    }
+    case MNewObject::ObjectCreate: {
+      pushArg(ImmGCPtr(templateObject));
+
+      using Fn = PlainObject* (*)(JSContext*, Handle<PlainObject*>);
+      callVM<Fn, ObjectCreateWithTemplate>(lir);
+      break;
+    }
+  }
+
+  masm.storeCallPointerResult(objReg);
+
+  MOZ_ASSERT(!lir->safepoint()->liveRegs().has(objReg));
+  restoreLive(lir);
+}
+
+static bool ShouldInitFixedSlots(LNewPlainObject* lir, const Shape* shape,
+                                 uint32_t nfixed) {
+  // Look for StoreFixedSlot instructions following an object allocation
+  // that write to this object before a GC is triggered or this object is
+  // passed to a VM call. If all fixed slots will be initialized, the
+  // allocation code doesn't need to set the slots to |undefined|.
+
+  if (nfixed == 0) {
+    return false;
+  }
+
+  // Keep track of the fixed slots that are initialized. initializedSlots is
+  // a bit mask with a bit for each slot.
+  MOZ_ASSERT(nfixed <= NativeObject::MAX_FIXED_SLOTS);
+  static_assert(NativeObject::MAX_FIXED_SLOTS <= 32,
+                "Slot bits must fit in 32 bits");
+  uint32_t initializedSlots = 0;
+  uint32_t numInitialized = 0;
+
+  MInstruction* allocMir = lir->mir();
+  MBasicBlock* block = allocMir->block();
+
+  // Skip the allocation instruction.
+  MInstructionIterator iter = block->begin(allocMir);
+  MOZ_ASSERT(*iter == allocMir);
+  iter++;
+
+  // Handle the leading shape guard, if present.
+  for (; iter != block->end(); iter++) {
+    if (iter->isConstant()) {
+      // This instruction won't trigger a GC or read object slots.
+      continue;
+    }
+    if (iter->isGuardShape()) {
+      auto* guard = iter->toGuardShape();
+      if (guard->object() != allocMir || guard->shape() != shape) {
+        return true;
+      }
+      allocMir = guard;
+      iter++;
+    }
+    break;
+  }
+
+  for (; iter != block->end(); iter++) {
+    if (iter->isConstant() || iter->isPostWriteBarrier()) {
+      // These instructions won't trigger a GC or read object slots.
+      continue;
+    }
+
+    if (iter->isStoreFixedSlot()) {
+      MStoreFixedSlot* store = iter->toStoreFixedSlot();
+      if (store->object() != allocMir) {
+        return true;
+      }
+
+      // We may not initialize this object slot on allocation, so the
+      // pre-barrier could read uninitialized memory. Simply disable
+      // the barrier for this store: the object was just initialized
+      // so the barrier is not necessary.
+      store->setNeedsBarrier(false);
+
+      uint32_t slot = store->slot();
+      MOZ_ASSERT(slot < nfixed);
+      if ((initializedSlots & (1 << slot)) == 0) {
+        numInitialized++;
+        initializedSlots |= (1 << slot);
+
+        if (numInitialized == nfixed) {
+          // All fixed slots will be initialized.
+          MOZ_ASSERT(mozilla::CountPopulation32(initializedSlots) == nfixed);
+          return false;
+        }
+      }
+      continue;
+    }
+
+    // Unhandled instruction, assume it bails or reads object slots.
+    return true;
+  }
+
+  MOZ_CRASH("Shouldn't get here");
+}
+
+void CodeGenerator::visitNewObject(LNewObject* lir) {
+  Register objReg = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp());
+
+  if (lir->mir()->isVMCall()) {
+    visitNewObjectVMCall(lir);
+    return;
+  }
+
+  OutOfLineNewObject* ool = new (alloc()) OutOfLineNewObject(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  TemplateObject templateObject(lir->mir()->templateObject());
+
+  masm.createGCObject(objReg, tempReg, templateObject,
+                      lir->mir()->initialHeap(), ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineNewObject(OutOfLineNewObject* ool) {
+  visitNewObjectVMCall(ool->lir());
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitNewPlainObject(LNewPlainObject* lir) {
+  Register objReg = ToRegister(lir->output());
+  Register temp0Reg = ToRegister(lir->temp0());
+  Register temp1Reg = ToRegister(lir->temp1());
+  Register shapeReg = ToRegister(lir->temp2());
+
+  auto* mir = lir->mir();
+  const Shape* shape = mir->shape();
+  gc::Heap initialHeap = mir->initialHeap();
+  gc::AllocKind allocKind = mir->allocKind();
+
+  using Fn =
+      JSObject* (*)(JSContext*, Handle<SharedShape*>, gc::AllocKind, gc::Heap);
+  OutOfLineCode* ool = oolCallVM<Fn, NewPlainObjectOptimizedFallback>(
+      lir,
+      ArgList(ImmGCPtr(shape), Imm32(int32_t(allocKind)),
+              Imm32(int32_t(initialHeap))),
+      StoreRegisterTo(objReg));
+
+  bool initContents = ShouldInitFixedSlots(lir, shape, mir->numFixedSlots());
+
+  masm.movePtr(ImmGCPtr(shape), shapeReg);
+  masm.createPlainGCObject(
+      objReg, shapeReg, temp0Reg, temp1Reg, mir->numFixedSlots(),
+      mir->numDynamicSlots(), allocKind, initialHeap, ool->entry(),
+      AllocSiteInput(gc::CatchAllAllocSite::Optimized), initContents);
+
+#ifdef DEBUG
+  // ShouldInitFixedSlots expects that the leading GuardShape will never fail,
+  // so ensure the newly created object has the correct shape. Should the guard
+  // ever fail, we may end up with uninitialized fixed slots, which can confuse
+  // the GC.
+  Label ok;
+  masm.branchTestObjShape(Assembler::Equal, objReg, shape, temp0Reg, objReg,
+                          &ok);
+  masm.assumeUnreachable("Newly created object has the correct shape");
+  masm.bind(&ok);
+#endif
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewArrayObject(LNewArrayObject* lir) {
+  Register objReg = ToRegister(lir->output());
+  Register temp0Reg = ToRegister(lir->temp0());
+  Register shapeReg = ToRegister(lir->temp1());
+
+  auto* mir = lir->mir();
+  uint32_t arrayLength = mir->length();
+
+  gc::AllocKind allocKind = GuessArrayGCKind(arrayLength);
+  MOZ_ASSERT(CanChangeToBackgroundAllocKind(allocKind, &ArrayObject::class_));
+  allocKind = ForegroundToBackgroundAllocKind(allocKind);
+
+  uint32_t slotCount = GetGCKindSlots(allocKind);
+  MOZ_ASSERT(slotCount >= ObjectElements::VALUES_PER_HEADER);
+  uint32_t arrayCapacity = slotCount - ObjectElements::VALUES_PER_HEADER;
+
+  const Shape* shape = mir->shape();
+
+  NewObjectKind objectKind =
+      mir->initialHeap() == gc::Heap::Tenured ? TenuredObject : GenericObject;
+
+  using Fn =
+      ArrayObject* (*)(JSContext*, uint32_t, gc::AllocKind, NewObjectKind);
+  OutOfLineCode* ool = oolCallVM<Fn, NewArrayObjectOptimizedFallback>(
+      lir,
+      ArgList(Imm32(arrayLength), Imm32(int32_t(allocKind)), Imm32(objectKind)),
+      StoreRegisterTo(objReg));
+
+  masm.movePtr(ImmPtr(shape), shapeReg);
+  masm.createArrayWithFixedElements(
+      objReg, shapeReg, temp0Reg, arrayLength, arrayCapacity, allocKind,
+      mir->initialHeap(), ool->entry(),
+      AllocSiteInput(gc::CatchAllAllocSite::Optimized));
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewNamedLambdaObject(LNewNamedLambdaObject* lir) {
+  Register objReg = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp0());
+  const CompileInfo& info = lir->mir()->block()->info();
+
+  using Fn = js::NamedLambdaObject* (*)(JSContext*, HandleFunction);
+  OutOfLineCode* ool = oolCallVM<Fn, NamedLambdaObject::createWithoutEnclosing>(
+      lir, ArgList(info.funMaybeLazy()), StoreRegisterTo(objReg));
+
+  TemplateObject templateObject(lir->mir()->templateObj());
+
+  masm.createGCObject(objReg, tempReg, templateObject, gc::Heap::Default,
+                      ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewCallObject(LNewCallObject* lir) {
+  Register objReg = ToRegister(lir->output());
+  Register tempReg = ToRegister(lir->temp0());
+
+  CallObject* templateObj = lir->mir()->templateObject();
+
+  using Fn = CallObject* (*)(JSContext*, Handle<SharedShape*>);
+  OutOfLineCode* ool = oolCallVM<Fn, CallObject::createWithShape>(
+      lir, ArgList(ImmGCPtr(templateObj->sharedShape())),
+      StoreRegisterTo(objReg));
+
+  // Inline call object creation, using the OOL path only for tricky cases.
+  TemplateObject templateObject(templateObj);
+  masm.createGCObject(objReg, tempReg, templateObject, gc::Heap::Default,
+                      ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitNewStringObject(LNewStringObject* lir) {
+  Register input = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  StringObject* templateObj = lir->mir()->templateObj();
+
+  using Fn = JSObject* (*)(JSContext*, HandleString);
+  OutOfLineCode* ool = oolCallVM<Fn, NewStringObject>(lir, ArgList(input),
+                                                      StoreRegisterTo(output));
+
+  TemplateObject templateObject(templateObj);
+  masm.createGCObject(output, temp, templateObject, gc::Heap::Default,
+                      ool->entry());
+
+  masm.loadStringLength(input, temp);
+
+  masm.storeValue(JSVAL_TYPE_STRING, input,
+                  Address(output, StringObject::offsetOfPrimitiveValue()));
+  masm.storeValue(JSVAL_TYPE_INT32, temp,
+                  Address(output, StringObject::offsetOfLength()));
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitInitElemGetterSetter(LInitElemGetterSetter* lir) {
+  Register obj = ToRegister(lir->object());
+  Register value = ToRegister(lir->value());
+
+  pushArg(value);
+  pushArg(ToValue(lir, LInitElemGetterSetter::IdIndex));
+  pushArg(obj);
+  pushArg(ImmPtr(lir->mir()->resumePoint()->pc()));
+
+  using Fn = bool (*)(JSContext*, jsbytecode*, HandleObject, HandleValue,
+                      HandleObject);
+  callVM<Fn, InitElemGetterSetterOperation>(lir);
+}
+
+void CodeGenerator::visitMutateProto(LMutateProto* lir) {
+  Register objReg = ToRegister(lir->object());
+
+  pushArg(ToValue(lir, LMutateProto::ValueIndex));
+  pushArg(objReg);
+
+  using Fn =
+      bool (*)(JSContext* cx, Handle<PlainObject*> obj, HandleValue value);
+  callVM<Fn, MutatePrototype>(lir);
+}
+
+void CodeGenerator::visitInitPropGetterSetter(LInitPropGetterSetter* lir) {
+  Register obj = ToRegister(lir->object());
+  Register value = ToRegister(lir->value());
+
+  pushArg(value);
+  pushArg(ImmGCPtr(lir->mir()->name()));
+  pushArg(obj);
+  pushArg(ImmPtr(lir->mir()->resumePoint()->pc()));
+
+  using Fn = bool (*)(JSContext*, jsbytecode*, HandleObject,
+                      Handle<PropertyName*>, HandleObject);
+  callVM<Fn, InitPropGetterSetterOperation>(lir);
+}
+
+void CodeGenerator::visitCreateThis(LCreateThis* lir) {
+  const LAllocation* callee = lir->callee();
+  const LAllocation* newTarget = lir->newTarget();
+
+  if (newTarget->isConstant()) {
+    pushArg(ImmGCPtr(&newTarget->toConstant()->toObject()));
+  } else {
+    pushArg(ToRegister(newTarget));
+  }
+
+  if (callee->isConstant()) {
+    pushArg(ImmGCPtr(&callee->toConstant()->toObject()));
+  } else {
+    pushArg(ToRegister(callee));
+  }
+
+  using Fn = bool (*)(JSContext* cx, HandleObject callee,
+                      HandleObject newTarget, MutableHandleValue rval);
+  callVM<Fn, jit::CreateThisFromIon>(lir);
+}
+
+void CodeGenerator::visitCreateArgumentsObject(LCreateArgumentsObject* lir) {
+  // This should be getting constructed in the first block only, and not any OSR
+  // entry blocks.
+  MOZ_ASSERT(lir->mir()->block()->id() == 0);
+
+  Register callObj = ToRegister(lir->callObject());
+  Register temp0 = ToRegister(lir->temp0());
+  Label done;
+
+  if (ArgumentsObject* templateObj = lir->mir()->templateObject()) {
+    Register objTemp = ToRegister(lir->temp1());
+    Register cxTemp = ToRegister(lir->temp2());
+
+    masm.Push(callObj);
+
+    // Try to allocate an arguments object. This will leave the reserved
+    // slots uninitialized, so it's important we don't GC until we
+    // initialize these slots in ArgumentsObject::finishForIonPure.
+    Label failure;
+    TemplateObject templateObject(templateObj);
+    masm.createGCObject(objTemp, temp0, templateObject, gc::Heap::Default,
+                        &failure,
+                        /* initContents = */ false);
+
+    masm.moveStackPtrTo(temp0);
+    masm.addPtr(Imm32(masm.framePushed()), temp0);
+
+    using Fn = ArgumentsObject* (*)(JSContext* cx, jit::JitFrameLayout* frame,
+                                    JSObject* scopeChain, ArgumentsObject* obj);
+    masm.setupAlignedABICall();
+    masm.loadJSContext(cxTemp);
+    masm.passABIArg(cxTemp);
+    masm.passABIArg(temp0);
+    masm.passABIArg(callObj);
+    masm.passABIArg(objTemp);
+
+    masm.callWithABI<Fn, ArgumentsObject::finishForIonPure>();
+    masm.branchTestPtr(Assembler::Zero, ReturnReg, ReturnReg, &failure);
+
+    // Discard saved callObj on the stack.
+    masm.addToStackPtr(Imm32(sizeof(uintptr_t)));
+    masm.jump(&done);
+
+    masm.bind(&failure);
+    masm.Pop(callObj);
+  }
+
+  masm.moveStackPtrTo(temp0);
+  masm.addPtr(Imm32(frameSize()), temp0);
+
+  pushArg(callObj);
+  pushArg(temp0);
+
+  using Fn = ArgumentsObject* (*)(JSContext*, JitFrameLayout*, HandleObject);
+  callVM<Fn, ArgumentsObject::createForIon>(lir);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitCreateInlinedArgumentsObject(
+    LCreateInlinedArgumentsObject* lir) {
+  Register callObj = ToRegister(lir->getCallObject());
+  Register callee = ToRegister(lir->getCallee());
+  Register argsAddress = ToRegister(lir->temp1());
+  Register argsObj = ToRegister(lir->temp2());
+
+  // TODO: Do we have to worry about alignment here?
+
+  // Create a contiguous array of values for ArgumentsObject::create
+  // by pushing the arguments onto the stack in reverse order.
+  uint32_t argc = lir->mir()->numActuals();
+  for (uint32_t i = 0; i < argc; i++) {
+    uint32_t argNum = argc - i - 1;
+    uint32_t index = LCreateInlinedArgumentsObject::ArgIndex(argNum);
+    ConstantOrRegister arg =
+        toConstantOrRegister(lir, index, lir->mir()->getArg(argNum)->type());
+    masm.Push(arg);
+  }
+  masm.moveStackPtrTo(argsAddress);
+
+  Label done;
+  if (ArgumentsObject* templateObj = lir->mir()->templateObject()) {
+    LiveRegisterSet liveRegs;
+    liveRegs.add(callObj);
+    liveRegs.add(callee);
+
+    masm.PushRegsInMask(liveRegs);
+
+    // We are free to clobber all registers, as LCreateInlinedArgumentsObject is
+    // a call instruction.
+    AllocatableGeneralRegisterSet allRegs(GeneralRegisterSet::All());
+    allRegs.take(callObj);
+    allRegs.take(callee);
+    allRegs.take(argsObj);
+    allRegs.take(argsAddress);
+
+    Register temp3 = allRegs.takeAny();
+    Register temp4 = allRegs.takeAny();
+
+    // Try to allocate an arguments object. This will leave the reserved slots
+    // uninitialized, so it's important we don't GC until we initialize these
+    // slots in ArgumentsObject::finishForIonPure.
+    Label failure;
+    TemplateObject templateObject(templateObj);
+    masm.createGCObject(argsObj, temp3, templateObject, gc::Heap::Default,
+                        &failure,
+                        /* initContents = */ false);
+
+    Register numActuals = temp3;
+    masm.move32(Imm32(argc), numActuals);
+
+    using Fn = ArgumentsObject* (*)(JSContext*, JSObject*, JSFunction*, Value*,
+                                    uint32_t, ArgumentsObject*);
+    masm.setupAlignedABICall();
+    masm.loadJSContext(temp4);
+    masm.passABIArg(temp4);
+    masm.passABIArg(callObj);
+    masm.passABIArg(callee);
+    masm.passABIArg(argsAddress);
+    masm.passABIArg(numActuals);
+    masm.passABIArg(argsObj);
+
+    masm.callWithABI<Fn, ArgumentsObject::finishInlineForIonPure>();
+    masm.branchTestPtr(Assembler::Zero, ReturnReg, ReturnReg, &failure);
+
+    // Discard saved callObj, callee, and values array on the stack.
+    masm.addToStackPtr(
+        Imm32(masm.PushRegsInMaskSizeInBytes(liveRegs) + argc * sizeof(Value)));
+    masm.jump(&done);
+
+    masm.bind(&failure);
+    masm.PopRegsInMask(liveRegs);
+
+    // Reload argsAddress because it may have been overridden.
+    masm.moveStackPtrTo(argsAddress);
+  }
+
+  pushArg(Imm32(argc));
+  pushArg(callObj);
+  pushArg(callee);
+  pushArg(argsAddress);
+
+  using Fn = ArgumentsObject* (*)(JSContext*, Value*, HandleFunction,
+                                  HandleObject, uint32_t);
+  callVM<Fn, ArgumentsObject::createForInlinedIon>(lir);
+
+  // Discard the array of values.
+  masm.freeStack(argc * sizeof(Value));
+
+  masm.bind(&done);
+}
+
+template <class GetInlinedArgument>
+void CodeGenerator::emitGetInlinedArgument(GetInlinedArgument* lir,
+                                           Register index,
+                                           ValueOperand output) {
+  uint32_t numActuals = lir->mir()->numActuals();
+  MOZ_ASSERT(numActuals <= ArgumentsObject::MaxInlinedArgs);
+
+  // The index has already been bounds-checked, so the code we
+  // generate here should be unreachable. We can end up in this
+  // situation in self-hosted code using GetArgument(), or in a
+  // monomorphically inlined function if we've inlined some CacheIR
+  // that was created for a different caller.
+  if (numActuals == 0) {
+    masm.assumeUnreachable("LGetInlinedArgument: invalid index");
+    return;
+  }
+
+  // Check the first n-1 possible indices.
+  Label done;
+  for (uint32_t i = 0; i < numActuals - 1; i++) {
+    Label skip;
+    ConstantOrRegister arg = toConstantOrRegister(
+        lir, GetInlinedArgument::ArgIndex(i), lir->mir()->getArg(i)->type());
+    masm.branch32(Assembler::NotEqual, index, Imm32(i), &skip);
+    masm.moveValue(arg, output);
+
+    masm.jump(&done);
+    masm.bind(&skip);
+  }
+
+#ifdef DEBUG
+  Label skip;
+  masm.branch32(Assembler::Equal, index, Imm32(numActuals - 1), &skip);
+  masm.assumeUnreachable("LGetInlinedArgument: invalid index");
+  masm.bind(&skip);
+#endif
+
+  // The index has already been bounds-checked, so load the last argument.
+  uint32_t lastIdx = numActuals - 1;
+  ConstantOrRegister arg =
+      toConstantOrRegister(lir, GetInlinedArgument::ArgIndex(lastIdx),
+                           lir->mir()->getArg(lastIdx)->type());
+  masm.moveValue(arg, output);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGetInlinedArgument(LGetInlinedArgument* lir) {
+  Register index = ToRegister(lir->getIndex());
+  ValueOperand output = ToOutValue(lir);
+
+  emitGetInlinedArgument(lir, index, output);
+}
+
+void CodeGenerator::visitGetInlinedArgumentHole(LGetInlinedArgumentHole* lir) {
+  Register index = ToRegister(lir->getIndex());
+  ValueOperand output = ToOutValue(lir);
+
+  uint32_t numActuals = lir->mir()->numActuals();
+
+  if (numActuals == 0) {
+    bailoutCmp32(Assembler::LessThan, index, Imm32(0), lir->snapshot());
+    masm.moveValue(UndefinedValue(), output);
+    return;
+  }
+
+  Label outOfBounds, done;
+  masm.branch32(Assembler::AboveOrEqual, index, Imm32(numActuals),
+                &outOfBounds);
+
+  emitGetInlinedArgument(lir, index, output);
+  masm.jump(&done);
+
+  masm.bind(&outOfBounds);
+  bailoutCmp32(Assembler::LessThan, index, Imm32(0), lir->snapshot());
+  masm.moveValue(UndefinedValue(), output);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGetArgumentsObjectArg(LGetArgumentsObjectArg* lir) {
+  Register temp = ToRegister(lir->temp0());
+  Register argsObj = ToRegister(lir->argsObject());
+  ValueOperand out = ToOutValue(lir);
+
+  masm.loadPrivate(Address(argsObj, ArgumentsObject::getDataSlotOffset()),
+                   temp);
+  Address argAddr(temp, ArgumentsData::offsetOfArgs() +
+                            lir->mir()->argno() * sizeof(Value));
+  masm.loadValue(argAddr, out);
+#ifdef DEBUG
+  Label success;
+  masm.branchTestMagic(Assembler::NotEqual, out, &success);
+  masm.assumeUnreachable(
+      "Result from ArgumentObject shouldn't be JSVAL_TYPE_MAGIC.");
+  masm.bind(&success);
+#endif
+}
+
+void CodeGenerator::visitSetArgumentsObjectArg(LSetArgumentsObjectArg* lir) {
+  Register temp = ToRegister(lir->getTemp(0));
+  Register argsObj = ToRegister(lir->argsObject());
+  ValueOperand value = ToValue(lir, LSetArgumentsObjectArg::ValueIndex);
+
+  masm.loadPrivate(Address(argsObj, ArgumentsObject::getDataSlotOffset()),
+                   temp);
+  Address argAddr(temp, ArgumentsData::offsetOfArgs() +
+                            lir->mir()->argno() * sizeof(Value));
+  emitPreBarrier(argAddr);
+#ifdef DEBUG
+  Label success;
+  masm.branchTestMagic(Assembler::NotEqual, argAddr, &success);
+  masm.assumeUnreachable(
+      "Result in ArgumentObject shouldn't be JSVAL_TYPE_MAGIC.");
+  masm.bind(&success);
+#endif
+  masm.storeValue(value, argAddr);
+}
+
+void CodeGenerator::visitLoadArgumentsObjectArg(LLoadArgumentsObjectArg* lir) {
+  Register temp = ToRegister(lir->temp0());
+  Register argsObj = ToRegister(lir->argsObject());
+  Register index = ToRegister(lir->index());
+  ValueOperand out = ToOutValue(lir);
+
+  Label bail;
+  masm.loadArgumentsObjectElement(argsObj, index, out, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitLoadArgumentsObjectArgHole(
+    LLoadArgumentsObjectArgHole* lir) {
+  Register temp = ToRegister(lir->temp0());
+  Register argsObj = ToRegister(lir->argsObject());
+  Register index = ToRegister(lir->index());
+  ValueOperand out = ToOutValue(lir);
+
+  Label bail;
+  masm.loadArgumentsObjectElementHole(argsObj, index, out, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitInArgumentsObjectArg(LInArgumentsObjectArg* lir) {
+  Register temp = ToRegister(lir->temp0());
+  Register argsObj = ToRegister(lir->argsObject());
+  Register index = ToRegister(lir->index());
+  Register out = ToRegister(lir->output());
+
+  Label bail;
+  masm.loadArgumentsObjectElementExists(argsObj, index, out, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitArgumentsObjectLength(LArgumentsObjectLength* lir) {
+  Register argsObj = ToRegister(lir->argsObject());
+  Register out = ToRegister(lir->output());
+
+  Label bail;
+  masm.loadArgumentsObjectLength(argsObj, out, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitArrayFromArgumentsObject(
+    LArrayFromArgumentsObject* lir) {
+  pushArg(ToRegister(lir->argsObject()));
+
+  using Fn = ArrayObject* (*)(JSContext*, Handle<ArgumentsObject*>);
+  callVM<Fn, js::ArrayFromArgumentsObject>(lir);
+}
+
+void CodeGenerator::visitGuardArgumentsObjectFlags(
+    LGuardArgumentsObjectFlags* lir) {
+  Register argsObj = ToRegister(lir->argsObject());
+  Register temp = ToRegister(lir->temp0());
+
+  Label bail;
+  masm.branchTestArgumentsObjectFlags(argsObj, temp, lir->mir()->flags(),
+                                      Assembler::NonZero, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitBoundFunctionNumArgs(LBoundFunctionNumArgs* lir) {
+  Register obj = ToRegister(lir->object());
+  Register output = ToRegister(lir->output());
+
+  masm.unboxInt32(Address(obj, BoundFunctionObject::offsetOfFlagsSlot()),
+                  output);
+  masm.rshift32(Imm32(BoundFunctionObject::NumBoundArgsShift), output);
+}
+
+void CodeGenerator::visitGuardBoundFunctionIsConstructor(
+    LGuardBoundFunctionIsConstructor* lir) {
+  Register obj = ToRegister(lir->object());
+
+  Label bail;
+  Address flagsSlot(obj, BoundFunctionObject::offsetOfFlagsSlot());
+  masm.branchTest32(Assembler::Zero, flagsSlot,
+                    Imm32(BoundFunctionObject::IsConstructorFlag), &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitReturnFromCtor(LReturnFromCtor* lir) {
+  ValueOperand value = ToValue(lir, LReturnFromCtor::ValueIndex);
+  Register obj = ToRegister(lir->object());
+  Register output = ToRegister(lir->output());
+
+  Label valueIsObject, end;
+
+  masm.branchTestObject(Assembler::Equal, value, &valueIsObject);
+
+  // Value is not an object. Return that other object.
+  masm.movePtr(obj, output);
+  masm.jump(&end);
+
+  // Value is an object. Return unbox(Value).
+  masm.bind(&valueIsObject);
+  Register payload = masm.extractObject(value, output);
+  if (payload != output) {
+    masm.movePtr(payload, output);
+  }
+
+  masm.bind(&end);
+}
+
+class OutOfLineBoxNonStrictThis : public OutOfLineCodeBase<CodeGenerator> {
+  LBoxNonStrictThis* ins_;
+
+ public:
+  explicit OutOfLineBoxNonStrictThis(LBoxNonStrictThis* ins) : ins_(ins) {}
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineBoxNonStrictThis(this);
+  }
+  LBoxNonStrictThis* ins() const { return ins_; }
+};
+
+void CodeGenerator::visitBoxNonStrictThis(LBoxNonStrictThis* lir) {
+  ValueOperand value = ToValue(lir, LBoxNonStrictThis::ValueIndex);
+  Register output = ToRegister(lir->output());
+
+  auto* ool = new (alloc()) OutOfLineBoxNonStrictThis(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  masm.fallibleUnboxObject(value, output, ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineBoxNonStrictThis(
+    OutOfLineBoxNonStrictThis* ool) {
+  LBoxNonStrictThis* lir = ool->ins();
+
+  ValueOperand value = ToValue(lir, LBoxNonStrictThis::ValueIndex);
+  Register output = ToRegister(lir->output());
+
+  Label notNullOrUndefined;
+  {
+    Label isNullOrUndefined;
+    ScratchTagScope tag(masm, value);
+    masm.splitTagForTest(value, tag);
+    masm.branchTestUndefined(Assembler::Equal, tag, &isNullOrUndefined);
+    masm.branchTestNull(Assembler::NotEqual, tag, &notNullOrUndefined);
+    masm.bind(&isNullOrUndefined);
+    masm.movePtr(ImmGCPtr(lir->mir()->globalThis()), output);
+    masm.jump(ool->rejoin());
+  }
+
+  masm.bind(&notNullOrUndefined);
+
+  saveLive(lir);
+
+  pushArg(value);
+  using Fn = JSObject* (*)(JSContext*, HandleValue);
+  callVM<Fn, BoxNonStrictThis>(lir);
+
+  StoreRegisterTo(output).generate(this);
+  restoreLiveIgnore(lir, StoreRegisterTo(output).clobbered());
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitImplicitThis(LImplicitThis* lir) {
+  pushArg(ImmGCPtr(lir->mir()->name()));
+  pushArg(ToRegister(lir->env()));
+
+  using Fn = bool (*)(JSContext*, HandleObject, Handle<PropertyName*>,
+                      MutableHandleValue);
+  callVM<Fn, ImplicitThisOperation>(lir);
+}
+
+void CodeGenerator::visitArrayLength(LArrayLength* lir) {
+  Register elements = ToRegister(lir->elements());
+  Register output = ToRegister(lir->output());
+
+  Address length(elements, ObjectElements::offsetOfLength());
+  masm.load32(length, output);
+
+  // Bail out if the length doesn't fit in int32.
+  bailoutTest32(Assembler::Signed, output, output, lir->snapshot());
+}
+
+static void SetLengthFromIndex(MacroAssembler& masm, const LAllocation* index,
+                               const Address& length) {
+  if (index->isConstant()) {
+    masm.store32(Imm32(ToInt32(index) + 1), length);
+  } else {
+    Register newLength = ToRegister(index);
+    masm.add32(Imm32(1), newLength);
+    masm.store32(newLength, length);
+    masm.sub32(Imm32(1), newLength);
+  }
+}
+
+void CodeGenerator::visitSetArrayLength(LSetArrayLength* lir) {
+  Address length(ToRegister(lir->elements()), ObjectElements::offsetOfLength());
+  SetLengthFromIndex(masm, lir->index(), length);
+}
+
+void CodeGenerator::visitFunctionLength(LFunctionLength* lir) {
+  Register function = ToRegister(lir->function());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+
+  // Get the JSFunction flags.
+  masm.load32(Address(function, JSFunction::offsetOfFlagsAndArgCount()),
+              output);
+
+  // Functions with a SelfHostedLazyScript must be compiled with the slow-path
+  // before the function length is known. If the length was previously resolved,
+  // the length property may be shadowed.
+  masm.branchTest32(
+      Assembler::NonZero, output,
+      Imm32(FunctionFlags::SELFHOSTLAZY | FunctionFlags::RESOLVED_LENGTH),
+      &bail);
+
+  masm.loadFunctionLength(function, output, output, &bail);
+
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitFunctionName(LFunctionName* lir) {
+  Register function = ToRegister(lir->function());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+
+  const JSAtomState& names = gen->runtime->names();
+  masm.loadFunctionName(function, output, ImmGCPtr(names.empty), &bail);
+
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+template <class OrderedHashTable>
+static void RangeFront(MacroAssembler&, Register, Register, Register);
+
+template <>
+void RangeFront<ValueMap>(MacroAssembler& masm, Register range, Register i,
+                          Register front) {
+  masm.loadPtr(Address(range, ValueMap::Range::offsetOfHashTable()), front);
+  masm.loadPtr(Address(front, ValueMap::offsetOfImplData()), front);
+
+  MOZ_ASSERT(ValueMap::offsetOfImplDataElement() == 0,
+             "offsetof(Data, element) is 0");
+  static_assert(ValueMap::sizeofImplData() == 24, "sizeof(Data) is 24");
+  masm.mulBy3(i, i);
+  masm.lshiftPtr(Imm32(3), i);
+  masm.addPtr(i, front);
+}
+
+template <>
+void RangeFront<ValueSet>(MacroAssembler& masm, Register range, Register i,
+                          Register front) {
+  masm.loadPtr(Address(range, ValueSet::Range::offsetOfHashTable()), front);
+  masm.loadPtr(Address(front, ValueSet::offsetOfImplData()), front);
+
+  MOZ_ASSERT(ValueSet::offsetOfImplDataElement() == 0,
+             "offsetof(Data, element) is 0");
+  static_assert(ValueSet::sizeofImplData() == 16, "sizeof(Data) is 16");
+  masm.lshiftPtr(Imm32(4), i);
+  masm.addPtr(i, front);
+}
+
+template <class OrderedHashTable>
+static void RangePopFront(MacroAssembler& masm, Register range, Register front,
+                          Register dataLength, Register temp) {
+  Register i = temp;
+
+  masm.add32(Imm32(1),
+             Address(range, OrderedHashTable::Range::offsetOfCount()));
+
+  masm.load32(Address(range, OrderedHashTable::Range::offsetOfI()), i);
+
+  Label done, seek;
+  masm.bind(&seek);
+  masm.add32(Imm32(1), i);
+  masm.branch32(Assembler::AboveOrEqual, i, dataLength, &done);
+
+  // We can add sizeof(Data) to |front| to select the next element, because
+  // |front| and |range.ht.data[i]| point to the same location.
+  MOZ_ASSERT(OrderedHashTable::offsetOfImplDataElement() == 0,
+             "offsetof(Data, element) is 0");
+  masm.addPtr(Imm32(OrderedHashTable::sizeofImplData()), front);
+
+  masm.branchTestMagic(Assembler::Equal,
+                       Address(front, OrderedHashTable::offsetOfEntryKey()),
+                       JS_HASH_KEY_EMPTY, &seek);
+
+  masm.bind(&done);
+  masm.store32(i, Address(range, OrderedHashTable::Range::offsetOfI()));
+}
+
+template <class OrderedHashTable>
+static inline void RangeDestruct(MacroAssembler& masm, Register iter,
+                                 Register range, Register temp0,
+                                 Register temp1) {
+  Register next = temp0;
+  Register prevp = temp1;
+
+  masm.loadPtr(Address(range, OrderedHashTable::Range::offsetOfNext()), next);
+  masm.loadPtr(Address(range, OrderedHashTable::Range::offsetOfPrevP()), prevp);
+  masm.storePtr(next, Address(prevp, 0));
+
+  Label hasNoNext;
+  masm.branchTestPtr(Assembler::Zero, next, next, &hasNoNext);
+
+  masm.storePtr(prevp, Address(next, OrderedHashTable::Range::offsetOfPrevP()));
+
+  masm.bind(&hasNoNext);
+
+  Label nurseryAllocated;
+  masm.branchPtrInNurseryChunk(Assembler::Equal, iter, temp0,
+                               &nurseryAllocated);
+
+  masm.callFreeStub(range);
+
+  masm.bind(&nurseryAllocated);
+}
+
+template <>
+void CodeGenerator::emitLoadIteratorValues<ValueMap>(Register result,
+                                                     Register temp,
+                                                     Register front) {
+  size_t elementsOffset = NativeObject::offsetOfFixedElements();
+
+  Address keyAddress(front, ValueMap::Entry::offsetOfKey());
+  Address valueAddress(front, ValueMap::Entry::offsetOfValue());
+  Address keyElemAddress(result, elementsOffset);
+  Address valueElemAddress(result, elementsOffset + sizeof(Value));
+  masm.guardedCallPreBarrier(keyElemAddress, MIRType::Value);
+  masm.guardedCallPreBarrier(valueElemAddress, MIRType::Value);
+  masm.storeValue(keyAddress, keyElemAddress, temp);
+  masm.storeValue(valueAddress, valueElemAddress, temp);
+
+  Label emitBarrier, skipBarrier;
+  masm.branchValueIsNurseryCell(Assembler::Equal, keyAddress, temp,
+                                &emitBarrier);
+  masm.branchValueIsNurseryCell(Assembler::NotEqual, valueAddress, temp,
+                                &skipBarrier);
+  {
+    masm.bind(&emitBarrier);
+    saveVolatile(temp);
+    emitPostWriteBarrier(result);
+    restoreVolatile(temp);
+  }
+  masm.bind(&skipBarrier);
+}
+
+template <>
+void CodeGenerator::emitLoadIteratorValues<ValueSet>(Register result,
+                                                     Register temp,
+                                                     Register front) {
+  size_t elementsOffset = NativeObject::offsetOfFixedElements();
+
+  Address keyAddress(front, ValueSet::offsetOfEntryKey());
+  Address keyElemAddress(result, elementsOffset);
+  masm.guardedCallPreBarrier(keyElemAddress, MIRType::Value);
+  masm.storeValue(keyAddress, keyElemAddress, temp);
+
+  Label skipBarrier;
+  masm.branchValueIsNurseryCell(Assembler::NotEqual, keyAddress, temp,
+                                &skipBarrier);
+  {
+    saveVolatile(temp);
+    emitPostWriteBarrier(result);
+    restoreVolatile(temp);
+  }
+  masm.bind(&skipBarrier);
+}
+
+template <class IteratorObject, class OrderedHashTable>
+void CodeGenerator::emitGetNextEntryForIterator(LGetNextEntryForIterator* lir) {
+  Register iter = ToRegister(lir->iter());
+  Register result = ToRegister(lir->result());
+  Register temp = ToRegister(lir->temp0());
+  Register dataLength = ToRegister(lir->temp1());
+  Register range = ToRegister(lir->temp2());
+  Register output = ToRegister(lir->output());
+
+#ifdef DEBUG
+  // Self-hosted code is responsible for ensuring GetNextEntryForIterator is
+  // only called with the correct iterator class. Assert here all self-
+  // hosted callers of GetNextEntryForIterator perform this class check.
+  // No Spectre mitigations are needed because this is DEBUG-only code.
+  Label success;
+  masm.branchTestObjClassNoSpectreMitigations(
+      Assembler::Equal, iter, &IteratorObject::class_, temp, &success);
+  masm.assumeUnreachable("Iterator object should have the correct class.");
+  masm.bind(&success);
+#endif
+
+  masm.loadPrivate(Address(iter, NativeObject::getFixedSlotOffset(
+                                     IteratorObject::RangeSlot)),
+                   range);
+
+  Label iterAlreadyDone, iterDone, done;
+  masm.branchTestPtr(Assembler::Zero, range, range, &iterAlreadyDone);
+
+  masm.load32(Address(range, OrderedHashTable::Range::offsetOfI()), temp);
+  masm.loadPtr(Address(range, OrderedHashTable::Range::offsetOfHashTable()),
+               dataLength);
+  masm.load32(Address(dataLength, OrderedHashTable::offsetOfImplDataLength()),
+              dataLength);
+  masm.branch32(Assembler::AboveOrEqual, temp, dataLength, &iterDone);
+  {
+    masm.Push(iter);
+
+    Register front = iter;
+    RangeFront<OrderedHashTable>(masm, range, temp, front);
+
+    emitLoadIteratorValues<OrderedHashTable>(result, temp, front);
+
+    RangePopFront<OrderedHashTable>(masm, range, front, dataLength, temp);
+
+    masm.Pop(iter);
+    masm.move32(Imm32(0), output);
+  }
+  masm.jump(&done);
+  {
+    masm.bind(&iterDone);
+
+    RangeDestruct<OrderedHashTable>(masm, iter, range, temp, dataLength);
+
+    masm.storeValue(PrivateValue(nullptr),
+                    Address(iter, NativeObject::getFixedSlotOffset(
+                                      IteratorObject::RangeSlot)));
+
+    masm.bind(&iterAlreadyDone);
+
+    masm.move32(Imm32(1), output);
+  }
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGetNextEntryForIterator(
+    LGetNextEntryForIterator* lir) {
+  if (lir->mir()->mode() == MGetNextEntryForIterator::Map) {
+    emitGetNextEntryForIterator<MapIteratorObject, ValueMap>(lir);
+  } else {
+    MOZ_ASSERT(lir->mir()->mode() == MGetNextEntryForIterator::Set);
+    emitGetNextEntryForIterator<SetIteratorObject, ValueSet>(lir);
+  }
+}
+
+// The point of these is to inform Ion of where these values already are; they
+// don't normally generate (much) code.
+void CodeGenerator::visitWasmRegisterPairResult(LWasmRegisterPairResult* lir) {}
+void CodeGenerator::visitWasmStackResult(LWasmStackResult* lir) {}
+void CodeGenerator::visitWasmStackResult64(LWasmStackResult64* lir) {}
+
+void CodeGenerator::visitWasmStackResultArea(LWasmStackResultArea* lir) {
+  LAllocation* output = lir->getDef(0)->output();
+  MOZ_ASSERT(output->isStackArea());
+  bool tempInit = false;
+  for (auto iter = output->toStackArea()->results(); iter; iter.next()) {
+    // Zero out ref stack results.
+    if (iter.isGcPointer()) {
+      Register temp = ToRegister(lir->temp0());
+      if (!tempInit) {
+        masm.xorPtr(temp, temp);
+        tempInit = true;
+      }
+      masm.storePtr(temp, ToAddress(iter.alloc()));
+    }
+  }
+}
+
+void CodeGenerator::visitWasmRegisterResult(LWasmRegisterResult* lir) {
+#ifdef JS_64BIT
+  if (MWasmRegisterResult* mir = lir->mir()) {
+    if (mir->type() == MIRType::Int32) {
+      masm.widenInt32(ToRegister(lir->output()));
+    }
+  }
+#endif
+}
+
+void CodeGenerator::visitWasmCall(LWasmCall* lir) {
+  const MWasmCallBase* callBase = lir->callBase();
+
+  // If this call is in Wasm try code block, initialise a wasm::TryNote for this
+  // call.
+  bool inTry = callBase->inTry();
+  if (inTry) {
+    size_t tryNoteIndex = callBase->tryNoteIndex();
+    wasm::TryNoteVector& tryNotes = masm.tryNotes();
+    wasm::TryNote& tryNote = tryNotes[tryNoteIndex];
+    tryNote.setTryBodyBegin(masm.currentOffset());
+  }
+
+  MOZ_ASSERT((sizeof(wasm::Frame) + masm.framePushed()) % WasmStackAlignment ==
+             0);
+  static_assert(
+      WasmStackAlignment >= ABIStackAlignment &&
+          WasmStackAlignment % ABIStackAlignment == 0,
+      "The wasm stack alignment should subsume the ABI-required alignment");
+
+#ifdef DEBUG
+  Label ok;
+  masm.branchTestStackPtr(Assembler::Zero, Imm32(WasmStackAlignment - 1), &ok);
+  masm.breakpoint();
+  masm.bind(&ok);
+#endif
+
+  // LWasmCallBase::isCallPreserved() assumes that all MWasmCalls preserve the
+  // instance and pinned regs. The only case where where we don't have to
+  // reload the instance and pinned regs is when the callee preserves them.
+  bool reloadRegs = true;
+  bool switchRealm = true;
+
+  const wasm::CallSiteDesc& desc = callBase->desc();
+  const wasm::CalleeDesc& callee = callBase->callee();
+  CodeOffset retOffset;
+  CodeOffset secondRetOffset;
+  switch (callee.which()) {
+    case wasm::CalleeDesc::Func:
+      retOffset = masm.call(desc, callee.funcIndex());
+      reloadRegs = false;
+      switchRealm = false;
+      break;
+    case wasm::CalleeDesc::Import:
+      retOffset = masm.wasmCallImport(desc, callee);
+      break;
+    case wasm::CalleeDesc::AsmJSTable:
+      retOffset = masm.asmCallIndirect(desc, callee);
+      break;
+    case wasm::CalleeDesc::WasmTable: {
+      Label* boundsCheckFailed = nullptr;
+      if (lir->needsBoundsCheck()) {
+        OutOfLineAbortingWasmTrap* ool =
+            new (alloc()) OutOfLineAbortingWasmTrap(
+                wasm::BytecodeOffset(desc.lineOrBytecode()),
+                wasm::Trap::OutOfBounds);
+        if (lir->isCatchable()) {
+          addOutOfLineCode(ool, lir->mirCatchable());
+        } else {
+          addOutOfLineCode(ool, lir->mirUncatchable());
+        }
+        boundsCheckFailed = ool->entry();
+      }
+      Label* nullCheckFailed = nullptr;
+#ifndef WASM_HAS_HEAPREG
+      {
+        OutOfLineAbortingWasmTrap* ool =
+            new (alloc()) OutOfLineAbortingWasmTrap(
+                wasm::BytecodeOffset(desc.lineOrBytecode()),
+                wasm::Trap::IndirectCallToNull);
+        if (lir->isCatchable()) {
+          addOutOfLineCode(ool, lir->mirCatchable());
+        } else {
+          addOutOfLineCode(ool, lir->mirUncatchable());
+        }
+        nullCheckFailed = ool->entry();
+      }
+#endif
+      masm.wasmCallIndirect(desc, callee, boundsCheckFailed, nullCheckFailed,
+                            lir->tableSize(), &retOffset, &secondRetOffset);
+      // Register reloading and realm switching are handled dynamically inside
+      // wasmCallIndirect.  There are two return offsets, one for each call
+      // instruction (fast path and slow path).
+      reloadRegs = false;
+      switchRealm = false;
+      break;
+    }
+    case wasm::CalleeDesc::Builtin:
+      retOffset = masm.call(desc, callee.builtin());
+      reloadRegs = false;
+      switchRealm = false;
+      break;
+    case wasm::CalleeDesc::BuiltinInstanceMethod:
+      retOffset = masm.wasmCallBuiltinInstanceMethod(
+          desc, callBase->instanceArg(), callee.builtin(),
+          callBase->builtinMethodFailureMode());
+      switchRealm = false;
+      break;
+    case wasm::CalleeDesc::FuncRef:
+      // Register reloading and realm switching are handled dynamically inside
+      // wasmCallRef.  There are two return offsets, one for each call
+      // instruction (fast path and slow path).
+      masm.wasmCallRef(desc, callee, &retOffset, &secondRetOffset);
+      reloadRegs = false;
+      switchRealm = false;
+      break;
+  }
+
+  // Note the assembler offset for the associated LSafePoint.
+  markSafepointAt(retOffset.offset(), lir);
+
+  // Now that all the outbound in-memory args are on the stack, note the
+  // required lower boundary point of the associated StackMap.
+  uint32_t framePushedAtStackMapBase =
+      masm.framePushed() - callBase->stackArgAreaSizeUnaligned();
+  lir->safepoint()->setFramePushedAtStackMapBase(framePushedAtStackMapBase);
+  MOZ_ASSERT(!lir->safepoint()->isWasmTrap());
+
+  // Note the assembler offset and framePushed for use by the adjunct
+  // LSafePoint, see visitor for LWasmCallIndirectAdjunctSafepoint below.
+  if (callee.which() == wasm::CalleeDesc::WasmTable) {
+    lir->adjunctSafepoint()->recordSafepointInfo(secondRetOffset,
+                                                 framePushedAtStackMapBase);
+  }
+
+  if (reloadRegs) {
+    masm.loadPtr(
+        Address(masm.getStackPointer(), WasmCallerInstanceOffsetBeforeCall),
+        InstanceReg);
+    masm.loadWasmPinnedRegsFromInstance();
+    if (switchRealm) {
+      masm.switchToWasmInstanceRealm(ABINonArgReturnReg0, ABINonArgReturnReg1);
+    }
+  } else {
+    MOZ_ASSERT(!switchRealm);
+  }
+
+  if (inTry) {
+    // Set the end of the try note range
+    size_t tryNoteIndex = callBase->tryNoteIndex();
+    wasm::TryNoteVector& tryNotes = masm.tryNotes();
+    wasm::TryNote& tryNote = tryNotes[tryNoteIndex];
+
+    // Don't set the end of the try note if we've OOM'ed, as the above
+    // instructions may not have been emitted, which will trigger an assert
+    // about zero-length try-notes. This is okay as this compilation will be
+    // thrown away.
+    if (!masm.oom()) {
+      tryNote.setTryBodyEnd(masm.currentOffset());
+    }
+
+    // This instruction or the adjunct safepoint must be the last instruction
+    // in the block. No other instructions may be inserted.
+    LBlock* block = lir->block();
+    MOZ_RELEASE_ASSERT(*block->rbegin() == lir ||
+                       (block->rbegin()->isWasmCallIndirectAdjunctSafepoint() &&
+                        *(++block->rbegin()) == lir));
+
+    // Jump to the fallthrough block
+    jumpToBlock(lir->mirCatchable()->getSuccessor(
+        MWasmCallCatchable::FallthroughBranchIndex));
+  }
+}
+
+void CodeGenerator::visitWasmCallLandingPrePad(LWasmCallLandingPrePad* lir) {
+  LBlock* block = lir->block();
+  MWasmCallLandingPrePad* mir = lir->mir();
+  MBasicBlock* mirBlock = mir->block();
+  MBasicBlock* callMirBlock = mir->callBlock();
+
+  // This block must be the pre-pad successor of the call block. No blocks may
+  // be inserted between us, such as for critical edge splitting.
+  MOZ_RELEASE_ASSERT(mirBlock == callMirBlock->getSuccessor(
+                                     MWasmCallCatchable::PrePadBranchIndex));
+
+  // This instruction or a move group must be the first instruction in the
+  // block. No other instructions may be inserted.
+  MOZ_RELEASE_ASSERT(*block->begin() == lir || (block->begin()->isMoveGroup() &&
+                                                *(++block->begin()) == lir));
+
+  wasm::TryNoteVector& tryNotes = masm.tryNotes();
+  wasm::TryNote& tryNote = tryNotes[mir->tryNoteIndex()];
+  // Set the entry point for the call try note to be the beginning of this
+  // block. The above assertions (and assertions in visitWasmCall) guarantee
+  // that we are not skipping over instructions that should be executed.
+  tryNote.setLandingPad(block->label()->offset(), masm.framePushed());
+}
+
+void CodeGenerator::visitWasmCallIndirectAdjunctSafepoint(
+    LWasmCallIndirectAdjunctSafepoint* lir) {
+  markSafepointAt(lir->safepointLocation().offset(), lir);
+  lir->safepoint()->setFramePushedAtStackMapBase(
+      lir->framePushedAtStackMapBase());
+}
+
+template <typename InstructionWithMaybeTrapSite>
+void EmitSignalNullCheckTrapSite(MacroAssembler& masm,
+                                 InstructionWithMaybeTrapSite* ins) {
+  if (!ins->maybeTrap()) {
+    return;
+  }
+  wasm::BytecodeOffset trapOffset(ins->maybeTrap()->offset);
+  masm.append(wasm::Trap::NullPointerDereference,
+              wasm::TrapSite(masm.currentOffset(), trapOffset));
+}
+
+void CodeGenerator::visitWasmLoadSlot(LWasmLoadSlot* ins) {
+  MIRType type = ins->type();
+  MWideningOp wideningOp = ins->wideningOp();
+  Register container = ToRegister(ins->containerRef());
+  Address addr(container, ins->offset());
+  AnyRegister dst = ToAnyRegister(ins->output());
+
+  EmitSignalNullCheckTrapSite(masm, ins);
+  switch (type) {
+    case MIRType::Int32:
+      switch (wideningOp) {
+        case MWideningOp::None:
+          masm.load32(addr, dst.gpr());
+          break;
+        case MWideningOp::FromU16:
+          masm.load16ZeroExtend(addr, dst.gpr());
+          break;
+        case MWideningOp::FromS16:
+          masm.load16SignExtend(addr, dst.gpr());
+          break;
+        case MWideningOp::FromU8:
+          masm.load8ZeroExtend(addr, dst.gpr());
+          break;
+        case MWideningOp::FromS8:
+          masm.load8SignExtend(addr, dst.gpr());
+          break;
+        default:
+          MOZ_CRASH("unexpected widening op in ::visitWasmLoadSlot");
+      }
+      break;
+    case MIRType::Float32:
+      MOZ_ASSERT(wideningOp == MWideningOp::None);
+      masm.loadFloat32(addr, dst.fpu());
+      break;
+    case MIRType::Double:
+      MOZ_ASSERT(wideningOp == MWideningOp::None);
+      masm.loadDouble(addr, dst.fpu());
+      break;
+    case MIRType::Pointer:
+    case MIRType::RefOrNull:
+      MOZ_ASSERT(wideningOp == MWideningOp::None);
+      masm.loadPtr(addr, dst.gpr());
+      break;
+#ifdef ENABLE_WASM_SIMD
+    case MIRType::Simd128:
+      MOZ_ASSERT(wideningOp == MWideningOp::None);
+      masm.loadUnalignedSimd128(addr, dst.fpu());
+      break;
+#endif
+    default:
+      MOZ_CRASH("unexpected type in ::visitWasmLoadSlot");
+  }
+}
+
+void CodeGenerator::visitWasmStoreSlot(LWasmStoreSlot* ins) {
+  MIRType type = ins->type();
+  MNarrowingOp narrowingOp = ins->narrowingOp();
+  Register container = ToRegister(ins->containerRef());
+  Address addr(container, ins->offset());
+  AnyRegister src = ToAnyRegister(ins->value());
+  if (type != MIRType::Int32) {
+    MOZ_RELEASE_ASSERT(narrowingOp == MNarrowingOp::None);
+  }
+
+  EmitSignalNullCheckTrapSite(masm, ins);
+  switch (type) {
+    case MIRType::Int32:
+      switch (narrowingOp) {
+        case MNarrowingOp::None:
+          masm.store32(src.gpr(), addr);
+          break;
+        case MNarrowingOp::To16:
+          masm.store16(src.gpr(), addr);
+          break;
+        case MNarrowingOp::To8:
+          masm.store8(src.gpr(), addr);
+          break;
+        default:
+          MOZ_CRASH();
+      }
+      break;
+    case MIRType::Float32:
+      masm.storeFloat32(src.fpu(), addr);
+      break;
+    case MIRType::Double:
+      masm.storeDouble(src.fpu(), addr);
+      break;
+    case MIRType::Pointer:
+      // This could be correct, but it would be a new usage, so check carefully.
+      MOZ_CRASH("Unexpected type in visitWasmStoreSlot.");
+    case MIRType::RefOrNull:
+      MOZ_CRASH("Bad type in visitWasmStoreSlot. Use LWasmStoreRef.");
+#ifdef ENABLE_WASM_SIMD
+    case MIRType::Simd128:
+      masm.storeUnalignedSimd128(src.fpu(), addr);
+      break;
+#endif
+    default:
+      MOZ_CRASH("unexpected type in StorePrimitiveValue");
+  }
+}
+
+void CodeGenerator::visitWasmLoadTableElement(LWasmLoadTableElement* ins) {
+  Register elements = ToRegister(ins->elements());
+  Register index = ToRegister(ins->index());
+  Register output = ToRegister(ins->output());
+  masm.loadPtr(BaseIndex(elements, index, ScalePointer), output);
+}
+
+void CodeGenerator::visitWasmDerivedPointer(LWasmDerivedPointer* ins) {
+  masm.movePtr(ToRegister(ins->base()), ToRegister(ins->output()));
+  masm.addPtr(Imm32(int32_t(ins->offset())), ToRegister(ins->output()));
+}
+
+void CodeGenerator::visitWasmDerivedIndexPointer(
+    LWasmDerivedIndexPointer* ins) {
+  Register base = ToRegister(ins->base());
+  Register index = ToRegister(ins->index());
+  Register output = ToRegister(ins->output());
+  masm.computeEffectiveAddress(BaseIndex(base, index, ins->scale()), output);
+}
+
+void CodeGenerator::visitWasmStoreRef(LWasmStoreRef* ins) {
+  Register instance = ToRegister(ins->instance());
+  Register valueBase = ToRegister(ins->valueBase());
+  size_t offset = ins->offset();
+  Register value = ToRegister(ins->value());
+  Register temp = ToRegister(ins->temp0());
+
+  if (ins->preBarrierKind() == WasmPreBarrierKind::Normal) {
+    Label skipPreBarrier;
+    wasm::EmitWasmPreBarrierGuard(
+        masm, instance, temp, valueBase, offset, &skipPreBarrier,
+        ins->maybeTrap() ? &ins->maybeTrap()->offset : nullptr);
+    wasm::EmitWasmPreBarrierCall(masm, instance, temp, valueBase, offset);
+    masm.bind(&skipPreBarrier);
+  }
+
+  EmitSignalNullCheckTrapSite(masm, ins);
+  masm.storePtr(value, Address(valueBase, offset));
+  // The postbarrier is handled separately.
+}
+
+// Out-of-line path to update the store buffer for wasm references.
+class OutOfLineWasmCallPostWriteBarrier
+    : public OutOfLineCodeBase<CodeGenerator> {
+  LInstruction* lir_;
+  Register valueBase_;
+  Register temp_;
+  uint32_t valueOffset_;
+
+ public:
+  OutOfLineWasmCallPostWriteBarrier(LInstruction* lir, Register valueBase,
+                                    Register temp, uint32_t valueOffset)
+      : lir_(lir),
+        valueBase_(valueBase),
+        temp_(temp),
+        valueOffset_(valueOffset) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineWasmCallPostWriteBarrier(this);
+  }
+
+  LInstruction* lir() const { return lir_; }
+  Register valueBase() const { return valueBase_; }
+  Register temp() const { return temp_; }
+  uint32_t valueOffset() const { return valueOffset_; }
+};
+
+void CodeGenerator::visitOutOfLineWasmCallPostWriteBarrier(
+    OutOfLineWasmCallPostWriteBarrier* ool) {
+  saveLiveVolatile(ool->lir());
+  masm.Push(InstanceReg);
+  int32_t framePushedAfterInstance = masm.framePushed();
+
+  // Fold the value offset into the value base
+  Register valueAddr = ool->valueBase();
+  Register temp = ool->temp();
+  masm.computeEffectiveAddress(Address(valueAddr, ool->valueOffset()), temp);
+
+  // Call Instance::postBarrier
+  masm.setupWasmABICall();
+  masm.passABIArg(InstanceReg);
+  masm.passABIArg(temp);
+  int32_t instanceOffset = masm.framePushed() - framePushedAfterInstance;
+  masm.callWithABI(wasm::BytecodeOffset(0), wasm::SymbolicAddress::PostBarrier,
+                   mozilla::Some(instanceOffset), MoveOp::GENERAL);
+
+  masm.Pop(InstanceReg);
+  restoreLiveVolatile(ool->lir());
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitWasmPostWriteBarrier(LWasmPostWriteBarrier* lir) {
+  Register object = ToRegister(lir->object());
+  Register value = ToRegister(lir->value());
+  Register valueBase = ToRegister(lir->valueBase());
+  Register temp = ToRegister(lir->temp0());
+  MOZ_ASSERT(ToRegister(lir->instance()) == InstanceReg);
+  auto ool = new (alloc()) OutOfLineWasmCallPostWriteBarrier(
+      lir, valueBase, temp, lir->valueOffset());
+  addOutOfLineCode(ool, lir->mir());
+
+  // If the pointer being stored is null, no barrier.
+  masm.branchTestPtr(Assembler::Zero, value, value, ool->rejoin());
+
+  // If there is a containing object and it is in the nursery, no barrier.
+  masm.branchPtrInNurseryChunk(Assembler::Equal, object, temp, ool->rejoin());
+
+  // If the pointer being stored is to a tenured object, no barrier.
+  masm.branchPtrInNurseryChunk(Assembler::Equal, value, temp, ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitWasmLoadSlotI64(LWasmLoadSlotI64* ins) {
+  Register container = ToRegister(ins->containerRef());
+  Address addr(container, ins->offset());
+  Register64 output = ToOutRegister64(ins);
+  EmitSignalNullCheckTrapSite(masm, ins);
+  masm.load64(addr, output);
+}
+
+void CodeGenerator::visitWasmStoreSlotI64(LWasmStoreSlotI64* ins) {
+  Register container = ToRegister(ins->containerRef());
+  Address addr(container, ins->offset());
+  Register64 value = ToRegister64(ins->value());
+  EmitSignalNullCheckTrapSite(masm, ins);
+  masm.store64(value, addr);
+}
+
+void CodeGenerator::visitArrayBufferByteLength(LArrayBufferByteLength* lir) {
+  Register obj = ToRegister(lir->object());
+  Register out = ToRegister(lir->output());
+  masm.loadArrayBufferByteLengthIntPtr(obj, out);
+}
+
+void CodeGenerator::visitArrayBufferViewLength(LArrayBufferViewLength* lir) {
+  Register obj = ToRegister(lir->object());
+  Register out = ToRegister(lir->output());
+  masm.loadArrayBufferViewLengthIntPtr(obj, out);
+}
+
+void CodeGenerator::visitArrayBufferViewByteOffset(
+    LArrayBufferViewByteOffset* lir) {
+  Register obj = ToRegister(lir->object());
+  Register out = ToRegister(lir->output());
+  masm.loadArrayBufferViewByteOffsetIntPtr(obj, out);
+}
+
+void CodeGenerator::visitArrayBufferViewElements(
+    LArrayBufferViewElements* lir) {
+  Register obj = ToRegister(lir->object());
+  Register out = ToRegister(lir->output());
+  masm.loadPtr(Address(obj, ArrayBufferViewObject::dataOffset()), out);
+}
+
+void CodeGenerator::visitTypedArrayElementSize(LTypedArrayElementSize* lir) {
+  Register obj = ToRegister(lir->object());
+  Register out = ToRegister(lir->output());
+
+  masm.typedArrayElementSize(obj, out);
+}
+
+void CodeGenerator::visitGuardHasAttachedArrayBuffer(
+    LGuardHasAttachedArrayBuffer* lir) {
+  Register obj = ToRegister(lir->object());
+  Register temp = ToRegister(lir->temp0());
+
+  Label bail;
+  masm.branchIfHasDetachedArrayBuffer(obj, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+class OutOfLineGuardNumberToIntPtrIndex
+    : public OutOfLineCodeBase<CodeGenerator> {
+  LGuardNumberToIntPtrIndex* lir_;
+
+ public:
+  explicit OutOfLineGuardNumberToIntPtrIndex(LGuardNumberToIntPtrIndex* lir)
+      : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineGuardNumberToIntPtrIndex(this);
+  }
+  LGuardNumberToIntPtrIndex* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitGuardNumberToIntPtrIndex(
+    LGuardNumberToIntPtrIndex* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  if (!lir->mir()->supportOOB()) {
+    Label bail;
+    masm.convertDoubleToPtr(input, output, &bail, false);
+    bailoutFrom(&bail, lir->snapshot());
+    return;
+  }
+
+  auto* ool = new (alloc()) OutOfLineGuardNumberToIntPtrIndex(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  masm.convertDoubleToPtr(input, output, ool->entry(), false);
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineGuardNumberToIntPtrIndex(
+    OutOfLineGuardNumberToIntPtrIndex* ool) {
+  // Substitute the invalid index with an arbitrary out-of-bounds index.
+  masm.movePtr(ImmWord(-1), ToRegister(ool->lir()->output()));
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitStringLength(LStringLength* lir) {
+  Register input = ToRegister(lir->string());
+  Register output = ToRegister(lir->output());
+
+  masm.loadStringLength(input, output);
+}
+
+void CodeGenerator::visitMinMaxI(LMinMaxI* ins) {
+  Register first = ToRegister(ins->first());
+  Register output = ToRegister(ins->output());
+
+  MOZ_ASSERT(first == output);
+
+  Assembler::Condition cond =
+      ins->mir()->isMax() ? Assembler::GreaterThan : Assembler::LessThan;
+
+  if (ins->second()->isConstant()) {
+    Label done;
+    masm.branch32(cond, first, Imm32(ToInt32(ins->second())), &done);
+    masm.move32(Imm32(ToInt32(ins->second())), output);
+    masm.bind(&done);
+  } else {
+    Register second = ToRegister(ins->second());
+    masm.cmp32Move32(cond, second, first, second, output);
+  }
+}
+
+void CodeGenerator::visitMinMaxArrayI(LMinMaxArrayI* ins) {
+  Register array = ToRegister(ins->array());
+  Register output = ToRegister(ins->output());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  bool isMax = ins->isMax();
+
+  Label bail;
+  masm.minMaxArrayInt32(array, output, temp1, temp2, temp3, isMax, &bail);
+  bailoutFrom(&bail, ins->snapshot());
+}
+
+void CodeGenerator::visitMinMaxArrayD(LMinMaxArrayD* ins) {
+  Register array = ToRegister(ins->array());
+  FloatRegister output = ToFloatRegister(ins->output());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  FloatRegister floatTemp = ToFloatRegister(ins->floatTemp());
+  bool isMax = ins->isMax();
+
+  Label bail;
+  masm.minMaxArrayNumber(array, output, floatTemp, temp1, temp2, isMax, &bail);
+  bailoutFrom(&bail, ins->snapshot());
+}
+
+// For Abs*, lowering will have tied input to output on platforms where that is
+// sensible, and otherwise left them untied.
+
+void CodeGenerator::visitAbsI(LAbsI* ins) {
+  Register input = ToRegister(ins->input());
+  Register output = ToRegister(ins->output());
+
+  if (ins->mir()->fallible()) {
+    Label positive;
+    if (input != output) {
+      masm.move32(input, output);
+    }
+    masm.branchTest32(Assembler::NotSigned, output, output, &positive);
+    Label bail;
+    masm.branchNeg32(Assembler::Overflow, output, &bail);
+    bailoutFrom(&bail, ins->snapshot());
+    masm.bind(&positive);
+  } else {
+    masm.abs32(input, output);
+  }
+}
+
+void CodeGenerator::visitAbsD(LAbsD* ins) {
+  masm.absDouble(ToFloatRegister(ins->input()), ToFloatRegister(ins->output()));
+}
+
+void CodeGenerator::visitAbsF(LAbsF* ins) {
+  masm.absFloat32(ToFloatRegister(ins->input()),
+                  ToFloatRegister(ins->output()));
+}
+
+void CodeGenerator::visitPowII(LPowII* ins) {
+  Register value = ToRegister(ins->value());
+  Register power = ToRegister(ins->power());
+  Register output = ToRegister(ins->output());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+
+  Label bailout;
+  masm.pow32(value, power, output, temp0, temp1, &bailout);
+  bailoutFrom(&bailout, ins->snapshot());
+}
+
+void CodeGenerator::visitPowI(LPowI* ins) {
+  FloatRegister value = ToFloatRegister(ins->value());
+  Register power = ToRegister(ins->power());
+
+  using Fn = double (*)(double x, int32_t y);
+  masm.setupAlignedABICall();
+  masm.passABIArg(value, MoveOp::DOUBLE);
+  masm.passABIArg(power);
+
+  masm.callWithABI<Fn, js::powi>(MoveOp::DOUBLE);
+  MOZ_ASSERT(ToFloatRegister(ins->output()) == ReturnDoubleReg);
+}
+
+void CodeGenerator::visitPowD(LPowD* ins) {
+  FloatRegister value = ToFloatRegister(ins->value());
+  FloatRegister power = ToFloatRegister(ins->power());
+
+  using Fn = double (*)(double x, double y);
+  masm.setupAlignedABICall();
+  masm.passABIArg(value, MoveOp::DOUBLE);
+  masm.passABIArg(power, MoveOp::DOUBLE);
+  masm.callWithABI<Fn, ecmaPow>(MoveOp::DOUBLE);
+
+  MOZ_ASSERT(ToFloatRegister(ins->output()) == ReturnDoubleReg);
+}
+
+void CodeGenerator::visitPowOfTwoI(LPowOfTwoI* ins) {
+  Register power = ToRegister(ins->power());
+  Register output = ToRegister(ins->output());
+
+  uint32_t base = ins->base();
+  MOZ_ASSERT(mozilla::IsPowerOfTwo(base));
+
+  uint32_t n = mozilla::FloorLog2(base);
+  MOZ_ASSERT(n != 0);
+
+  // Hacker's Delight, 2nd edition, theorem D2.
+  auto ceilingDiv = [](uint32_t x, uint32_t y) { return (x + y - 1) / y; };
+
+  // Take bailout if |power| is greater-or-equals |log_y(2^31)| or is negative.
+  // |2^(n*y) < 2^31| must hold, hence |n*y < 31| resp. |y < 31/n|.
+  //
+  // Note: it's important for this condition to match the code in CacheIR.cpp
+  // (CanAttachInt32Pow) to prevent failure loops.
+  bailoutCmp32(Assembler::AboveOrEqual, power, Imm32(ceilingDiv(31, n)),
+               ins->snapshot());
+
+  // Compute (2^n)^y as 2^(n*y) using repeated shifts. We could directly scale
+  // |power| and perform a single shift, but due to the lack of necessary
+  // MacroAssembler functionality, like multiplying a register with an
+  // immediate, we restrict the number of generated shift instructions when
+  // lowering this operation.
+  masm.move32(Imm32(1), output);
+  do {
+    masm.lshift32(power, output);
+    n--;
+  } while (n > 0);
+}
+
+void CodeGenerator::visitSqrtD(LSqrtD* ins) {
+  FloatRegister input = ToFloatRegister(ins->input());
+  FloatRegister output = ToFloatRegister(ins->output());
+  masm.sqrtDouble(input, output);
+}
+
+void CodeGenerator::visitSqrtF(LSqrtF* ins) {
+  FloatRegister input = ToFloatRegister(ins->input());
+  FloatRegister output = ToFloatRegister(ins->output());
+  masm.sqrtFloat32(input, output);
+}
+
+void CodeGenerator::visitSignI(LSignI* ins) {
+  Register input = ToRegister(ins->input());
+  Register output = ToRegister(ins->output());
+  masm.signInt32(input, output);
+}
+
+void CodeGenerator::visitSignD(LSignD* ins) {
+  FloatRegister input = ToFloatRegister(ins->input());
+  FloatRegister output = ToFloatRegister(ins->output());
+  masm.signDouble(input, output);
+}
+
+void CodeGenerator::visitSignDI(LSignDI* ins) {
+  FloatRegister input = ToFloatRegister(ins->input());
+  FloatRegister temp = ToFloatRegister(ins->temp0());
+  Register output = ToRegister(ins->output());
+
+  Label bail;
+  masm.signDoubleToInt32(input, output, temp, &bail);
+  bailoutFrom(&bail, ins->snapshot());
+}
+
+void CodeGenerator::visitMathFunctionD(LMathFunctionD* ins) {
+  FloatRegister input = ToFloatRegister(ins->input());
+  MOZ_ASSERT(ToFloatRegister(ins->output()) == ReturnDoubleReg);
+
+  UnaryMathFunction fun = ins->mir()->function();
+  UnaryMathFunctionType funPtr = GetUnaryMathFunctionPtr(fun);
+
+  masm.setupAlignedABICall();
+
+  masm.passABIArg(input, MoveOp::DOUBLE);
+  masm.callWithABI(DynamicFunction<UnaryMathFunctionType>(funPtr),
+                   MoveOp::DOUBLE);
+}
+
+void CodeGenerator::visitMathFunctionF(LMathFunctionF* ins) {
+  FloatRegister input = ToFloatRegister(ins->input());
+  MOZ_ASSERT(ToFloatRegister(ins->output()) == ReturnFloat32Reg);
+
+  masm.setupAlignedABICall();
+  masm.passABIArg(input, MoveOp::FLOAT32);
+
+  using Fn = float (*)(float x);
+  Fn funptr = nullptr;
+  CheckUnsafeCallWithABI check = CheckUnsafeCallWithABI::Check;
+  switch (ins->mir()->function()) {
+    case UnaryMathFunction::Floor:
+      funptr = floorf;
+      check = CheckUnsafeCallWithABI::DontCheckOther;
+      break;
+    case UnaryMathFunction::Round:
+      funptr = math_roundf_impl;
+      break;
+    case UnaryMathFunction::Trunc:
+      funptr = math_truncf_impl;
+      break;
+    case UnaryMathFunction::Ceil:
+      funptr = ceilf;
+      check = CheckUnsafeCallWithABI::DontCheckOther;
+      break;
+    default:
+      MOZ_CRASH("Unknown or unsupported float32 math function");
+  }
+
+  masm.callWithABI(DynamicFunction<Fn>(funptr), MoveOp::FLOAT32, check);
+}
+
+void CodeGenerator::visitModD(LModD* ins) {
+  MOZ_ASSERT(!gen->compilingWasm());
+
+  FloatRegister lhs = ToFloatRegister(ins->lhs());
+  FloatRegister rhs = ToFloatRegister(ins->rhs());
+
+  MOZ_ASSERT(ToFloatRegister(ins->output()) == ReturnDoubleReg);
+
+  using Fn = double (*)(double a, double b);
+  masm.setupAlignedABICall();
+  masm.passABIArg(lhs, MoveOp::DOUBLE);
+  masm.passABIArg(rhs, MoveOp::DOUBLE);
+  masm.callWithABI<Fn, NumberMod>(MoveOp::DOUBLE);
+}
+
+void CodeGenerator::visitModPowTwoD(LModPowTwoD* ins) {
+  FloatRegister lhs = ToFloatRegister(ins->lhs());
+  uint32_t divisor = ins->divisor();
+  MOZ_ASSERT(mozilla::IsPowerOfTwo(divisor));
+
+  FloatRegister output = ToFloatRegister(ins->output());
+
+  // Compute |n % d| using |copysign(n - (d * trunc(n / d)), n)|.
+  //
+  // This doesn't work if |d| isn't a power of two, because we may lose too much
+  // precision. For example |Number.MAX_VALUE % 3 == 2|, but
+  // |3 * trunc(Number.MAX_VALUE / 3) == Infinity|.
+
+  Label done;
+  {
+    ScratchDoubleScope scratch(masm);
+
+    // Subnormals can lead to performance degradation, which can make calling
+    // |fmod| faster than this inline implementation. Work around this issue by
+    // directly returning the input for any value in the interval ]-1, +1[.
+    Label notSubnormal;
+    masm.loadConstantDouble(1.0, scratch);
+    masm.loadConstantDouble(-1.0, output);
+    masm.branchDouble(Assembler::DoubleGreaterThanOrEqual, lhs, scratch,
+                      &notSubnormal);
+    masm.branchDouble(Assembler::DoubleLessThanOrEqual, lhs, output,
+                      &notSubnormal);
+
+    masm.moveDouble(lhs, output);
+    masm.jump(&done);
+
+    masm.bind(&notSubnormal);
+
+    if (divisor == 1) {
+      // The pattern |n % 1 == 0| is used to detect integer numbers. We can skip
+      // the multiplication by one in this case.
+      masm.moveDouble(lhs, output);
+      masm.nearbyIntDouble(RoundingMode::TowardsZero, output, scratch);
+      masm.subDouble(scratch, output);
+    } else {
+      masm.loadConstantDouble(1.0 / double(divisor), scratch);
+      masm.loadConstantDouble(double(divisor), output);
+
+      masm.mulDouble(lhs, scratch);
+      masm.nearbyIntDouble(RoundingMode::TowardsZero, scratch, scratch);
+      masm.mulDouble(output, scratch);
+
+      masm.moveDouble(lhs, output);
+      masm.subDouble(scratch, output);
+    }
+  }
+
+  masm.copySignDouble(output, lhs, output);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitWasmBuiltinModD(LWasmBuiltinModD* ins) {
+  masm.Push(InstanceReg);
+  int32_t framePushedAfterInstance = masm.framePushed();
+
+  FloatRegister lhs = ToFloatRegister(ins->lhs());
+  FloatRegister rhs = ToFloatRegister(ins->rhs());
+
+  MOZ_ASSERT(ToFloatRegister(ins->output()) == ReturnDoubleReg);
+
+  masm.setupWasmABICall();
+  masm.passABIArg(lhs, MoveOp::DOUBLE);
+  masm.passABIArg(rhs, MoveOp::DOUBLE);
+
+  int32_t instanceOffset = masm.framePushed() - framePushedAfterInstance;
+  masm.callWithABI(ins->mir()->bytecodeOffset(), wasm::SymbolicAddress::ModD,
+                   mozilla::Some(instanceOffset), MoveOp::DOUBLE);
+
+  masm.Pop(InstanceReg);
+}
+
+void CodeGenerator::visitBigIntAdd(LBigIntAdd* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::add>(ins, ArgList(lhs, rhs),
+                                         StoreRegisterTo(output));
+
+  // 0n + x == x
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(rhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // x + 0n == x
+  Label rhsNonZero;
+  masm.branchIfBigIntIsNonZero(rhs, &rhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&rhsNonZero);
+
+  // Call into the VM when either operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntNonZero(lhs, temp1, ool->entry());
+  masm.loadBigIntNonZero(rhs, temp2, ool->entry());
+
+  masm.branchAddPtr(Assembler::Overflow, temp2, temp1, ool->entry());
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntSub(LBigIntSub* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::sub>(ins, ArgList(lhs, rhs),
+                                         StoreRegisterTo(output));
+
+  // x - 0n == x
+  Label rhsNonZero;
+  masm.branchIfBigIntIsNonZero(rhs, &rhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&rhsNonZero);
+
+  // Call into the VM when either operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigInt(lhs, temp1, ool->entry());
+  masm.loadBigIntNonZero(rhs, temp2, ool->entry());
+
+  masm.branchSubPtr(Assembler::Overflow, temp2, temp1, ool->entry());
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntMul(LBigIntMul* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::mul>(ins, ArgList(lhs, rhs),
+                                         StoreRegisterTo(output));
+
+  // 0n * x == 0n
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // x * 0n == 0n
+  Label rhsNonZero;
+  masm.branchIfBigIntIsNonZero(rhs, &rhsNonZero);
+  masm.movePtr(rhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&rhsNonZero);
+
+  // Call into the VM when either operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntNonZero(lhs, temp1, ool->entry());
+  masm.loadBigIntNonZero(rhs, temp2, ool->entry());
+
+  masm.branchMulPtr(Assembler::Overflow, temp2, temp1, ool->entry());
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntDiv(LBigIntDiv* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::div>(ins, ArgList(lhs, rhs),
+                                         StoreRegisterTo(output));
+
+  // x / 0 throws an error.
+  if (ins->mir()->canBeDivideByZero()) {
+    masm.branchIfBigIntIsZero(rhs, ool->entry());
+  }
+
+  // 0n / x == 0n
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // Call into the VM when either operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntNonZero(lhs, temp1, ool->entry());
+  masm.loadBigIntNonZero(rhs, temp2, ool->entry());
+
+  // |BigInt::div()| returns |lhs| for |lhs / 1n|, which means there's no
+  // allocation which might trigger a minor GC to free up nursery space. This
+  // requires us to apply the same optimization here, otherwise we'd end up with
+  // always entering the OOL call, because the nursery is never evicted.
+  Label notOne;
+  masm.branchPtr(Assembler::NotEqual, temp2, ImmWord(1), &notOne);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&notOne);
+
+  static constexpr auto DigitMin = std::numeric_limits<
+      mozilla::SignedStdintTypeForSize<sizeof(BigInt::Digit)>::Type>::min();
+
+  // Handle an integer overflow from INT{32,64}_MIN / -1.
+  Label notOverflow;
+  masm.branchPtr(Assembler::NotEqual, temp1, ImmWord(DigitMin), &notOverflow);
+  masm.branchPtr(Assembler::Equal, temp2, ImmWord(-1), ool->entry());
+  masm.bind(&notOverflow);
+
+  emitBigIntDiv(ins, temp1, temp2, output, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntMod(LBigIntMod* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::mod>(ins, ArgList(lhs, rhs),
+                                         StoreRegisterTo(output));
+
+  // x % 0 throws an error.
+  if (ins->mir()->canBeDivideByZero()) {
+    masm.branchIfBigIntIsZero(rhs, ool->entry());
+  }
+
+  // 0n % x == 0n
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // Call into the VM when either operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntAbsolute(lhs, temp1, ool->entry());
+  masm.loadBigIntAbsolute(rhs, temp2, ool->entry());
+
+  // Similar to the case for BigInt division, we must apply the same allocation
+  // optimizations as performed in |BigInt::mod()|.
+  Label notBelow;
+  masm.branchPtr(Assembler::AboveOrEqual, temp1, temp2, &notBelow);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&notBelow);
+
+  // Convert both digits to signed pointer-sized values.
+  masm.bigIntDigitToSignedPtr(lhs, temp1, ool->entry());
+  masm.bigIntDigitToSignedPtr(rhs, temp2, ool->entry());
+
+  static constexpr auto DigitMin = std::numeric_limits<
+      mozilla::SignedStdintTypeForSize<sizeof(BigInt::Digit)>::Type>::min();
+
+  // Handle an integer overflow from INT{32,64}_MIN / -1.
+  Label notOverflow;
+  masm.branchPtr(Assembler::NotEqual, temp1, ImmWord(DigitMin), &notOverflow);
+  masm.branchPtr(Assembler::NotEqual, temp2, ImmWord(-1), &notOverflow);
+  masm.movePtr(ImmWord(0), temp1);
+  masm.bind(&notOverflow);
+
+  emitBigIntMod(ins, temp1, temp2, output, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntPow(LBigIntPow* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::pow>(ins, ArgList(lhs, rhs),
+                                         StoreRegisterTo(output));
+
+  // x ** -y throws an error.
+  if (ins->mir()->canBeNegativeExponent()) {
+    masm.branchIfBigIntIsNegative(rhs, ool->entry());
+  }
+
+  Register dest = temp1;
+  Register base = temp2;
+  Register exponent = output;
+
+  Label done;
+  masm.movePtr(ImmWord(1), dest);  // p = 1
+
+  // 1n ** y == 1n
+  // -1n ** y == 1n when y is even
+  // -1n ** y == -1n when y is odd
+  Label lhsNotOne;
+  masm.branch32(Assembler::Above, Address(lhs, BigInt::offsetOfLength()),
+                Imm32(1), &lhsNotOne);
+  masm.loadFirstBigIntDigitOrZero(lhs, base);
+  masm.branchPtr(Assembler::NotEqual, base, Imm32(1), &lhsNotOne);
+  {
+    masm.loadFirstBigIntDigitOrZero(rhs, exponent);
+
+    Label lhsNonNegative;
+    masm.branchIfBigIntIsNonNegative(lhs, &lhsNonNegative);
+    masm.branchTestPtr(Assembler::Zero, exponent, Imm32(1), &done);
+    masm.bind(&lhsNonNegative);
+    masm.movePtr(lhs, output);
+    masm.jump(ool->rejoin());
+  }
+  masm.bind(&lhsNotOne);
+
+  // x ** 0n == 1n
+  masm.branchIfBigIntIsZero(rhs, &done);
+
+  // 0n ** y == 0n with y != 0n
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  {
+    masm.movePtr(lhs, output);
+    masm.jump(ool->rejoin());
+  }
+  masm.bind(&lhsNonZero);
+
+  // Call into the VM when the exponent can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntAbsolute(rhs, exponent, ool->entry());
+
+  // x ** y with x > 1 and y >= DigitBits can't be pointer-sized.
+  masm.branchPtr(Assembler::AboveOrEqual, exponent, Imm32(BigInt::DigitBits),
+                 ool->entry());
+
+  // x ** 1n == x
+  Label rhsNotOne;
+  masm.branch32(Assembler::NotEqual, exponent, Imm32(1), &rhsNotOne);
+  {
+    masm.movePtr(lhs, output);
+    masm.jump(ool->rejoin());
+  }
+  masm.bind(&rhsNotOne);
+
+  // Call into the VM when the base operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntNonZero(lhs, base, ool->entry());
+
+  // MacroAssembler::pow32() adjusted to work on pointer-sized registers.
+  {
+    // m = base
+    // n = exponent
+
+    Label start, loop;
+    masm.jump(&start);
+    masm.bind(&loop);
+
+    // m *= m
+    masm.branchMulPtr(Assembler::Overflow, base, base, ool->entry());
+
+    masm.bind(&start);
+
+    // if ((n & 1) != 0) p *= m
+    Label even;
+    masm.branchTest32(Assembler::Zero, exponent, Imm32(1), &even);
+    masm.branchMulPtr(Assembler::Overflow, base, dest, ool->entry());
+    masm.bind(&even);
+
+    // n >>= 1
+    // if (n == 0) return p
+    masm.branchRshift32(Assembler::NonZero, Imm32(1), exponent, &loop);
+  }
+
+  MOZ_ASSERT(temp1 == dest);
+
+  // Create and return the result.
+  masm.bind(&done);
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntBitAnd(LBigIntBitAnd* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::bitAnd>(ins, ArgList(lhs, rhs),
+                                            StoreRegisterTo(output));
+
+  // 0n & x == 0n
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // x & 0n == 0n
+  Label rhsNonZero;
+  masm.branchIfBigIntIsNonZero(rhs, &rhsNonZero);
+  masm.movePtr(rhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&rhsNonZero);
+
+  // Call into the VM when either operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntNonZero(lhs, temp1, ool->entry());
+  masm.loadBigIntNonZero(rhs, temp2, ool->entry());
+
+  masm.andPtr(temp2, temp1);
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntBitOr(LBigIntBitOr* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::bitOr>(ins, ArgList(lhs, rhs),
+                                           StoreRegisterTo(output));
+
+  // 0n | x == x
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(rhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // x | 0n == x
+  Label rhsNonZero;
+  masm.branchIfBigIntIsNonZero(rhs, &rhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&rhsNonZero);
+
+  // Call into the VM when either operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntNonZero(lhs, temp1, ool->entry());
+  masm.loadBigIntNonZero(rhs, temp2, ool->entry());
+
+  masm.orPtr(temp2, temp1);
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntBitXor(LBigIntBitXor* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::bitXor>(ins, ArgList(lhs, rhs),
+                                            StoreRegisterTo(output));
+
+  // 0n ^ x == x
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(rhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // x ^ 0n == x
+  Label rhsNonZero;
+  masm.branchIfBigIntIsNonZero(rhs, &rhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&rhsNonZero);
+
+  // Call into the VM when either operand can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigIntNonZero(lhs, temp1, ool->entry());
+  masm.loadBigIntNonZero(rhs, temp2, ool->entry());
+
+  masm.xorPtr(temp2, temp1);
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntLsh(LBigIntLsh* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::lsh>(ins, ArgList(lhs, rhs),
+                                         StoreRegisterTo(output));
+
+  // 0n << x == 0n
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // x << 0n == x
+  Label rhsNonZero;
+  masm.branchIfBigIntIsNonZero(rhs, &rhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&rhsNonZero);
+
+  // Inline |BigInt::lsh| for the case when |lhs| contains a single digit.
+
+  Label rhsTooLarge;
+  masm.loadBigIntAbsolute(rhs, temp2, &rhsTooLarge);
+
+  // Call into the VM when the left-hand side operand can't be loaded into a
+  // pointer-sized register.
+  masm.loadBigIntAbsolute(lhs, temp1, ool->entry());
+
+  // Handle shifts exceeding |BigInt::DigitBits| first.
+  Label shift, create;
+  masm.branchPtr(Assembler::Below, temp2, Imm32(BigInt::DigitBits), &shift);
+  {
+    masm.bind(&rhsTooLarge);
+
+    // x << DigitBits with x != 0n always exceeds pointer-sized storage.
+    masm.branchIfBigIntIsNonNegative(rhs, ool->entry());
+
+    // x << -DigitBits == x >> DigitBits, which is either 0n or -1n.
+    masm.move32(Imm32(0), temp1);
+    masm.branchIfBigIntIsNonNegative(lhs, &create);
+    masm.move32(Imm32(1), temp1);
+    masm.jump(&create);
+  }
+  masm.bind(&shift);
+
+  Label nonNegative;
+  masm.branchIfBigIntIsNonNegative(rhs, &nonNegative);
+  {
+    masm.movePtr(temp1, temp3);
+
+    // |x << -y| is computed as |x >> y|.
+    masm.rshiftPtr(temp2, temp1);
+
+    // For negative numbers, round down if any bit was shifted out.
+    masm.branchIfBigIntIsNonNegative(lhs, &create);
+
+    // Compute |mask = (static_cast<Digit>(1) << shift) - 1|.
+    masm.movePtr(ImmWord(-1), output);
+    masm.lshiftPtr(temp2, output);
+    masm.notPtr(output);
+
+    // Add plus one when |(lhs.digit(0) & mask) != 0|.
+    masm.branchTestPtr(Assembler::Zero, output, temp3, &create);
+    masm.addPtr(ImmWord(1), temp1);
+    masm.jump(&create);
+  }
+  masm.bind(&nonNegative);
+  {
+    masm.movePtr(temp2, temp3);
+
+    // Compute |grow = lhs.digit(0) >> (DigitBits - shift)|.
+    masm.negPtr(temp2);
+    masm.addPtr(Imm32(BigInt::DigitBits), temp2);
+    masm.movePtr(temp1, output);
+    masm.rshiftPtr(temp2, output);
+
+    // Call into the VM when any bit will be shifted out.
+    masm.branchTestPtr(Assembler::NonZero, output, output, ool->entry());
+
+    masm.movePtr(temp3, temp2);
+    masm.lshiftPtr(temp2, temp1);
+  }
+  masm.bind(&create);
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigIntAbsolute(output, temp1);
+
+  // Set the sign bit when the left-hand side is negative.
+  masm.branchIfBigIntIsNonNegative(lhs, ool->rejoin());
+  masm.or32(Imm32(BigInt::signBitMask()),
+            Address(output, BigInt::offsetOfFlags()));
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntRsh(LBigIntRsh* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register rhs = ToRegister(ins->rhs());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::rsh>(ins, ArgList(lhs, rhs),
+                                         StoreRegisterTo(output));
+
+  // 0n >> x == 0n
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(lhs, &lhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // x >> 0n == x
+  Label rhsNonZero;
+  masm.branchIfBigIntIsNonZero(rhs, &rhsNonZero);
+  masm.movePtr(lhs, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&rhsNonZero);
+
+  // Inline |BigInt::rsh| for the case when |lhs| contains a single digit.
+
+  Label rhsTooLarge;
+  masm.loadBigIntAbsolute(rhs, temp2, &rhsTooLarge);
+
+  // Call into the VM when the left-hand side operand can't be loaded into a
+  // pointer-sized register.
+  masm.loadBigIntAbsolute(lhs, temp1, ool->entry());
+
+  // Handle shifts exceeding |BigInt::DigitBits| first.
+  Label shift, create;
+  masm.branchPtr(Assembler::Below, temp2, Imm32(BigInt::DigitBits), &shift);
+  {
+    masm.bind(&rhsTooLarge);
+
+    // x >> -DigitBits == x << DigitBits, which exceeds pointer-sized storage.
+    masm.branchIfBigIntIsNegative(rhs, ool->entry());
+
+    // x >> DigitBits is either 0n or -1n.
+    masm.move32(Imm32(0), temp1);
+    masm.branchIfBigIntIsNonNegative(lhs, &create);
+    masm.move32(Imm32(1), temp1);
+    masm.jump(&create);
+  }
+  masm.bind(&shift);
+
+  Label nonNegative;
+  masm.branchIfBigIntIsNonNegative(rhs, &nonNegative);
+  {
+    masm.movePtr(temp2, temp3);
+
+    // Compute |grow = lhs.digit(0) >> (DigitBits - shift)|.
+    masm.negPtr(temp2);
+    masm.addPtr(Imm32(BigInt::DigitBits), temp2);
+    masm.movePtr(temp1, output);
+    masm.rshiftPtr(temp2, output);
+
+    // Call into the VM when any bit will be shifted out.
+    masm.branchTestPtr(Assembler::NonZero, output, output, ool->entry());
+
+    // |x >> -y| is computed as |x << y|.
+    masm.movePtr(temp3, temp2);
+    masm.lshiftPtr(temp2, temp1);
+    masm.jump(&create);
+  }
+  masm.bind(&nonNegative);
+  {
+    masm.movePtr(temp1, temp3);
+
+    masm.rshiftPtr(temp2, temp1);
+
+    // For negative numbers, round down if any bit was shifted out.
+    masm.branchIfBigIntIsNonNegative(lhs, &create);
+
+    // Compute |mask = (static_cast<Digit>(1) << shift) - 1|.
+    masm.movePtr(ImmWord(-1), output);
+    masm.lshiftPtr(temp2, output);
+    masm.notPtr(output);
+
+    // Add plus one when |(lhs.digit(0) & mask) != 0|.
+    masm.branchTestPtr(Assembler::Zero, output, temp3, &create);
+    masm.addPtr(ImmWord(1), temp1);
+  }
+  masm.bind(&create);
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigIntAbsolute(output, temp1);
+
+  // Set the sign bit when the left-hand side is negative.
+  masm.branchIfBigIntIsNonNegative(lhs, ool->rejoin());
+  masm.or32(Imm32(BigInt::signBitMask()),
+            Address(output, BigInt::offsetOfFlags()));
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntIncrement(LBigIntIncrement* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt);
+  auto* ool =
+      oolCallVM<Fn, BigInt::inc>(ins, ArgList(input), StoreRegisterTo(output));
+
+  // Call into the VM when the input can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigInt(input, temp1, ool->entry());
+  masm.movePtr(ImmWord(1), temp2);
+
+  masm.branchAddPtr(Assembler::Overflow, temp2, temp1, ool->entry());
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntDecrement(LBigIntDecrement* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt);
+  auto* ool =
+      oolCallVM<Fn, BigInt::dec>(ins, ArgList(input), StoreRegisterTo(output));
+
+  // Call into the VM when the input can't be loaded into a pointer-sized
+  // register.
+  masm.loadBigInt(input, temp1, ool->entry());
+  masm.movePtr(ImmWord(1), temp2);
+
+  masm.branchSubPtr(Assembler::Overflow, temp2, temp1, ool->entry());
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigInt(output, temp1);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntNegate(LBigIntNegate* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp = ToRegister(ins->temp());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt);
+  auto* ool =
+      oolCallVM<Fn, BigInt::neg>(ins, ArgList(input), StoreRegisterTo(output));
+
+  // -0n == 0n
+  Label lhsNonZero;
+  masm.branchIfBigIntIsNonZero(input, &lhsNonZero);
+  masm.movePtr(input, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&lhsNonZero);
+
+  // Call into the VM when the input uses heap digits.
+  masm.copyBigIntWithInlineDigits(input, output, temp, initialBigIntHeap(),
+                                  ool->entry());
+
+  // Flip the sign bit.
+  masm.xor32(Imm32(BigInt::signBitMask()),
+             Address(output, BigInt::offsetOfFlags()));
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitBigIntBitNot(LBigIntBitNot* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt);
+  auto* ool = oolCallVM<Fn, BigInt::bitNot>(ins, ArgList(input),
+                                            StoreRegisterTo(output));
+
+  masm.loadBigIntAbsolute(input, temp1, ool->entry());
+
+  // This follows the C++ implementation because it let's us support the full
+  // range [-2^64, 2^64 - 1] on 64-bit resp. [-2^32, 2^32 - 1] on 32-bit.
+  Label nonNegative, done;
+  masm.branchIfBigIntIsNonNegative(input, &nonNegative);
+  {
+    // ~(-x) == ~(~(x-1)) == x-1
+    masm.subPtr(Imm32(1), temp1);
+    masm.jump(&done);
+  }
+  masm.bind(&nonNegative);
+  {
+    // ~x == -x-1 == -(x+1)
+    masm.movePtr(ImmWord(1), temp2);
+    masm.branchAddPtr(Assembler::CarrySet, temp2, temp1, ool->entry());
+  }
+  masm.bind(&done);
+
+  // Create and return the result.
+  masm.newGCBigInt(output, temp2, initialBigIntHeap(), ool->entry());
+  masm.initializeBigIntAbsolute(output, temp1);
+
+  // Set the sign bit when the input is positive.
+  masm.branchIfBigIntIsNegative(input, ool->rejoin());
+  masm.or32(Imm32(BigInt::signBitMask()),
+            Address(output, BigInt::offsetOfFlags()));
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitInt32ToStringWithBase(LInt32ToStringWithBase* lir) {
+  Register input = ToRegister(lir->input());
+  RegisterOrInt32 base = ToRegisterOrInt32(lir->base());
+  Register output = ToRegister(lir->output());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  using Fn = JSString* (*)(JSContext*, int32_t, int32_t);
+  if (base.is<Register>()) {
+    auto* ool = oolCallVM<Fn, js::Int32ToStringWithBase>(
+        lir, ArgList(input, base.as<Register>()), StoreRegisterTo(output));
+
+    LiveRegisterSet liveRegs = liveVolatileRegs(lir);
+    masm.loadInt32ToStringWithBase(input, base.as<Register>(), output, temp0,
+                                   temp1, gen->runtime->staticStrings(),
+                                   liveRegs, ool->entry());
+    masm.bind(ool->rejoin());
+  } else {
+    auto* ool = oolCallVM<Fn, js::Int32ToStringWithBase>(
+        lir, ArgList(input, Imm32(base.as<int32_t>())),
+        StoreRegisterTo(output));
+
+    masm.loadInt32ToStringWithBase(input, base.as<int32_t>(), output, temp0,
+                                   temp1, gen->runtime->staticStrings(),
+                                   ool->entry());
+    masm.bind(ool->rejoin());
+  }
+}
+
+void CodeGenerator::visitNumberParseInt(LNumberParseInt* lir) {
+  Register string = ToRegister(lir->string());
+  Register radix = ToRegister(lir->radix());
+  ValueOperand output = ToOutValue(lir);
+  Register temp = ToRegister(lir->temp0());
+
+#ifdef DEBUG
+  Label ok;
+  masm.branch32(Assembler::Equal, radix, Imm32(0), &ok);
+  masm.branch32(Assembler::Equal, radix, Imm32(10), &ok);
+  masm.assumeUnreachable("radix must be 0 or 10 for indexed value fast path");
+  masm.bind(&ok);
+#endif
+
+  // Use indexed value as fast path if possible.
+  Label vmCall, done;
+  masm.loadStringIndexValue(string, temp, &vmCall);
+  masm.tagValue(JSVAL_TYPE_INT32, temp, output);
+  masm.jump(&done);
+  {
+    masm.bind(&vmCall);
+
+    pushArg(radix);
+    pushArg(string);
+
+    using Fn = bool (*)(JSContext*, HandleString, int32_t, MutableHandleValue);
+    callVM<Fn, js::NumberParseInt>(lir);
+  }
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitDoubleParseInt(LDoubleParseInt* lir) {
+  FloatRegister number = ToFloatRegister(lir->number());
+  Register output = ToRegister(lir->output());
+  FloatRegister temp = ToFloatRegister(lir->temp0());
+
+  Label bail;
+  masm.branchDouble(Assembler::DoubleUnordered, number, number, &bail);
+  masm.branchTruncateDoubleToInt32(number, output, &bail);
+
+  Label ok;
+  masm.branch32(Assembler::NotEqual, output, Imm32(0), &ok);
+  {
+    // Accept both +0 and -0 and return 0.
+    masm.loadConstantDouble(0.0, temp);
+    masm.branchDouble(Assembler::DoubleEqual, number, temp, &ok);
+
+    // Fail if a non-zero input is in the exclusive range (-1, 1.0e-6).
+    masm.loadConstantDouble(DOUBLE_DECIMAL_IN_SHORTEST_LOW, temp);
+    masm.branchDouble(Assembler::DoubleLessThan, number, temp, &bail);
+  }
+  masm.bind(&ok);
+
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitFloor(LFloor* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+  masm.floorDoubleToInt32(input, output, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitFloorF(LFloorF* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+  masm.floorFloat32ToInt32(input, output, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitCeil(LCeil* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+  masm.ceilDoubleToInt32(input, output, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitCeilF(LCeilF* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+  masm.ceilFloat32ToInt32(input, output, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitRound(LRound* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  FloatRegister temp = ToFloatRegister(lir->temp0());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+  masm.roundDoubleToInt32(input, output, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitRoundF(LRoundF* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  FloatRegister temp = ToFloatRegister(lir->temp0());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+  masm.roundFloat32ToInt32(input, output, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitTrunc(LTrunc* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+  masm.truncDoubleToInt32(input, output, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitTruncF(LTruncF* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  Label bail;
+  masm.truncFloat32ToInt32(input, output, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitCompareS(LCompareS* lir) {
+  JSOp op = lir->mir()->jsop();
+  Register left = ToRegister(lir->left());
+  Register right = ToRegister(lir->right());
+  Register output = ToRegister(lir->output());
+
+  OutOfLineCode* ool = nullptr;
+
+  using Fn = bool (*)(JSContext*, HandleString, HandleString, bool*);
+  if (op == JSOp::Eq || op == JSOp::StrictEq) {
+    ool = oolCallVM<Fn, jit::StringsEqual<EqualityKind::Equal>>(
+        lir, ArgList(left, right), StoreRegisterTo(output));
+  } else if (op == JSOp::Ne || op == JSOp::StrictNe) {
+    ool = oolCallVM<Fn, jit::StringsEqual<EqualityKind::NotEqual>>(
+        lir, ArgList(left, right), StoreRegisterTo(output));
+  } else if (op == JSOp::Lt) {
+    ool = oolCallVM<Fn, jit::StringsCompare<ComparisonKind::LessThan>>(
+        lir, ArgList(left, right), StoreRegisterTo(output));
+  } else if (op == JSOp::Le) {
+    // Push the operands in reverse order for JSOp::Le:
+    // - |left <= right| is implemented as |right >= left|.
+    ool =
+        oolCallVM<Fn, jit::StringsCompare<ComparisonKind::GreaterThanOrEqual>>(
+            lir, ArgList(right, left), StoreRegisterTo(output));
+  } else if (op == JSOp::Gt) {
+    // Push the operands in reverse order for JSOp::Gt:
+    // - |left > right| is implemented as |right < left|.
+    ool = oolCallVM<Fn, jit::StringsCompare<ComparisonKind::LessThan>>(
+        lir, ArgList(right, left), StoreRegisterTo(output));
+  } else {
+    MOZ_ASSERT(op == JSOp::Ge);
+    ool =
+        oolCallVM<Fn, jit::StringsCompare<ComparisonKind::GreaterThanOrEqual>>(
+            lir, ArgList(left, right), StoreRegisterTo(output));
+  }
+
+  masm.compareStrings(op, left, right, output, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+template <typename T, typename CharT>
+static inline T CopyCharacters(const CharT* chars) {
+  T value = 0;
+  std::memcpy(&value, chars, sizeof(T));
+  return value;
+}
+
+template <typename T>
+static inline T CopyCharacters(const JSLinearString* str, size_t index) {
+  JS::AutoCheckCannotGC nogc;
+
+  if (str->hasLatin1Chars()) {
+    MOZ_ASSERT(index + sizeof(T) / sizeof(JS::Latin1Char) <= str->length());
+    return CopyCharacters<T>(str->latin1Chars(nogc) + index);
+  }
+
+  MOZ_ASSERT(sizeof(T) >= sizeof(char16_t));
+  MOZ_ASSERT(index + sizeof(T) / sizeof(char16_t) <= str->length());
+  return CopyCharacters<T>(str->twoByteChars(nogc) + index);
+}
+
+enum class CompareDirection { Forward, Backward };
+
+// NOTE: Clobbers the input when CompareDirection is backward.
+static void CompareCharacters(MacroAssembler& masm, Register input,
+                              const JSLinearString* str, Register output,
+                              JSOp op, CompareDirection direction, Label* done,
+                              Label* oolEntry) {
+  MOZ_ASSERT(input != output);
+
+  size_t length = str->length();
+  MOZ_ASSERT(length > 0);
+
+  CharEncoding encoding =
+      str->hasLatin1Chars() ? CharEncoding::Latin1 : CharEncoding::TwoByte;
+  size_t encodingSize = encoding == CharEncoding::Latin1
+                            ? sizeof(JS::Latin1Char)
+                            : sizeof(char16_t);
+  size_t byteLength = length * encodingSize;
+
+  // Take the OOL path when the string is a rope or has a different character
+  // representation.
+  masm.branchIfRope(input, oolEntry);
+  if (encoding == CharEncoding::Latin1) {
+    masm.branchTwoByteString(input, oolEntry);
+  } else {
+    JS::AutoCheckCannotGC nogc;
+    if (mozilla::IsUtf16Latin1(str->twoByteRange(nogc))) {
+      masm.branchLatin1String(input, oolEntry);
+    } else {
+      // This case was already handled in the caller.
+#ifdef DEBUG
+      Label ok;
+      masm.branchTwoByteString(input, &ok);
+      masm.assumeUnreachable("Unexpected Latin-1 string");
+      masm.bind(&ok);
+#endif
+    }
+  }
+
+#ifdef DEBUG
+  {
+    Label ok;
+    masm.branch32(Assembler::AboveOrEqual,
+                  Address(input, JSString::offsetOfLength()), Imm32(length),
+                  &ok);
+    masm.assumeUnreachable("Input mustn't be smaller than search string");
+    masm.bind(&ok);
+  }
+#endif
+
+  // Load the input string's characters.
+  Register stringChars = output;
+  masm.loadStringChars(input, stringChars, encoding);
+
+  if (direction == CompareDirection::Backward) {
+    masm.loadStringLength(input, input);
+    masm.sub32(Imm32(length), input);
+
+    masm.addToCharPtr(stringChars, input, encoding);
+  }
+
+  // Prefer a single compare-and-set instruction if possible.
+  if (byteLength == 1 || byteLength == 2 || byteLength == 4 ||
+      byteLength == 8) {
+    auto cond = JSOpToCondition(op, /* isSigned = */ false);
+
+    Address addr(stringChars, 0);
+    switch (byteLength) {
+      case 8: {
+        auto x = CopyCharacters<uint64_t>(str, 0);
+        masm.cmp64Set(cond, addr, Imm64(x), output);
+        break;
+      }
+      case 4: {
+        auto x = CopyCharacters<uint32_t>(str, 0);
+        masm.cmp32Set(cond, addr, Imm32(x), output);
+        break;
+      }
+      case 2: {
+        auto x = CopyCharacters<uint16_t>(str, 0);
+        masm.cmp16Set(cond, addr, Imm32(x), output);
+        break;
+      }
+      case 1: {
+        auto x = CopyCharacters<uint8_t>(str, 0);
+        masm.cmp8Set(cond, addr, Imm32(x), output);
+        break;
+      }
+    }
+  } else {
+    Label setNotEqualResult;
+
+    size_t pos = 0;
+    for (size_t stride : {8, 4, 2, 1}) {
+      while (byteLength >= stride) {
+        Address addr(stringChars, pos * encodingSize);
+        switch (stride) {
+          case 8: {
+            auto x = CopyCharacters<uint64_t>(str, pos);
+            masm.branch64(Assembler::NotEqual, addr, Imm64(x),
+                          &setNotEqualResult);
+            break;
+          }
+          case 4: {
+            auto x = CopyCharacters<uint32_t>(str, pos);
+            masm.branch32(Assembler::NotEqual, addr, Imm32(x),
+                          &setNotEqualResult);
+            break;
+          }
+          case 2: {
+            auto x = CopyCharacters<uint16_t>(str, pos);
+            masm.branch16(Assembler::NotEqual, addr, Imm32(x),
+                          &setNotEqualResult);
+            break;
+          }
+          case 1: {
+            auto x = CopyCharacters<uint8_t>(str, pos);
+            masm.branch8(Assembler::NotEqual, addr, Imm32(x),
+                         &setNotEqualResult);
+            break;
+          }
+        }
+
+        byteLength -= stride;
+        pos += stride / encodingSize;
+      }
+
+      // Prefer a single comparison for trailing bytes instead of doing
+      // multiple consecutive comparisons.
+      //
+      // For example when comparing against the string "example", emit two
+      // four-byte comparisons against "exam" and "mple" instead of doing
+      // three comparisons against "exam", "pl", and finally "e".
+      if (pos > 0 && byteLength > stride / 2) {
+        MOZ_ASSERT(stride == 8 || stride == 4);
+
+        size_t prev = pos - (stride - byteLength) / encodingSize;
+        Address addr(stringChars, prev * encodingSize);
+        switch (stride) {
+          case 8: {
+            auto x = CopyCharacters<uint64_t>(str, prev);
+            masm.branch64(Assembler::NotEqual, addr, Imm64(x),
+                          &setNotEqualResult);
+            break;
+          }
+          case 4: {
+            auto x = CopyCharacters<uint32_t>(str, prev);
+            masm.branch32(Assembler::NotEqual, addr, Imm32(x),
+                          &setNotEqualResult);
+            break;
+          }
+        }
+
+        // Break from the loop, because we've finished the complete string.
+        break;
+      }
+    }
+
+    // Falls through if both strings are equal.
+
+    masm.move32(Imm32(op == JSOp::Eq || op == JSOp::StrictEq), output);
+    masm.jump(done);
+
+    masm.bind(&setNotEqualResult);
+    masm.move32(Imm32(op == JSOp::Ne || op == JSOp::StrictNe), output);
+  }
+}
+
+void CodeGenerator::visitCompareSInline(LCompareSInline* lir) {
+  JSOp op = lir->mir()->jsop();
+  MOZ_ASSERT(IsEqualityOp(op));
+
+  Register input = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  const JSLinearString* str = lir->constant();
+  MOZ_ASSERT(str->length() > 0);
+
+  OutOfLineCode* ool = nullptr;
+
+  using Fn = bool (*)(JSContext*, HandleString, HandleString, bool*);
+  if (op == JSOp::Eq || op == JSOp::StrictEq) {
+    ool = oolCallVM<Fn, jit::StringsEqual<EqualityKind::Equal>>(
+        lir, ArgList(ImmGCPtr(str), input), StoreRegisterTo(output));
+  } else {
+    MOZ_ASSERT(op == JSOp::Ne || op == JSOp::StrictNe);
+    ool = oolCallVM<Fn, jit::StringsEqual<EqualityKind::NotEqual>>(
+        lir, ArgList(ImmGCPtr(str), input), StoreRegisterTo(output));
+  }
+
+  Label compareChars;
+  {
+    Label notPointerEqual;
+
+    // If operands point to the same instance, the strings are trivially equal.
+    masm.branchPtr(Assembler::NotEqual, input, ImmGCPtr(str), &notPointerEqual);
+    masm.move32(Imm32(op == JSOp::Eq || op == JSOp::StrictEq), output);
+    masm.jump(ool->rejoin());
+
+    masm.bind(&notPointerEqual);
+
+    Label setNotEqualResult;
+    if (str->isAtom()) {
+      // Atoms cannot be equal to each other if they point to different strings.
+      Imm32 atomBit(JSString::ATOM_BIT);
+      masm.branchTest32(Assembler::NonZero,
+                        Address(input, JSString::offsetOfFlags()), atomBit,
+                        &setNotEqualResult);
+    }
+
+    if (str->hasTwoByteChars()) {
+      // Pure two-byte strings can't be equal to Latin-1 strings.
+      JS::AutoCheckCannotGC nogc;
+      if (!mozilla::IsUtf16Latin1(str->twoByteRange(nogc))) {
+        masm.branchLatin1String(input, &setNotEqualResult);
+      }
+    }
+
+    // Strings of different length can never be equal.
+    masm.branch32(Assembler::Equal, Address(input, JSString::offsetOfLength()),
+                  Imm32(str->length()), &compareChars);
+
+    masm.bind(&setNotEqualResult);
+    masm.move32(Imm32(op == JSOp::Ne || op == JSOp::StrictNe), output);
+    masm.jump(ool->rejoin());
+  }
+
+  masm.bind(&compareChars);
+
+  CompareCharacters(masm, input, str, output, op, CompareDirection::Forward,
+                    ool->rejoin(), ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCompareBigInt(LCompareBigInt* lir) {
+  JSOp op = lir->mir()->jsop();
+  Register left = ToRegister(lir->left());
+  Register right = ToRegister(lir->right());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+  Register output = ToRegister(lir->output());
+
+  Label notSame;
+  Label compareSign;
+  Label compareLength;
+  Label compareDigit;
+
+  Label* notSameSign;
+  Label* notSameLength;
+  Label* notSameDigit;
+  if (IsEqualityOp(op)) {
+    notSameSign = &notSame;
+    notSameLength = &notSame;
+    notSameDigit = &notSame;
+  } else {
+    notSameSign = &compareSign;
+    notSameLength = &compareLength;
+    notSameDigit = &compareDigit;
+  }
+
+  masm.equalBigInts(left, right, temp0, temp1, temp2, output, notSameSign,
+                    notSameLength, notSameDigit);
+
+  Label done;
+  masm.move32(Imm32(op == JSOp::Eq || op == JSOp::StrictEq || op == JSOp::Le ||
+                    op == JSOp::Ge),
+              output);
+  masm.jump(&done);
+
+  if (IsEqualityOp(op)) {
+    masm.bind(&notSame);
+    masm.move32(Imm32(op == JSOp::Ne || op == JSOp::StrictNe), output);
+  } else {
+    Label invertWhenNegative;
+
+    // There are two cases when sign(left) != sign(right):
+    // 1. sign(left) = positive and sign(right) = negative,
+    // 2. or the dual case with reversed signs.
+    //
+    // For case 1, |left| <cmp> |right| is true for cmp=Gt or cmp=Ge and false
+    // for cmp=Lt or cmp=Le. Initialize the result for case 1 and handle case 2
+    // with |invertWhenNegative|.
+    masm.bind(&compareSign);
+    masm.move32(Imm32(op == JSOp::Gt || op == JSOp::Ge), output);
+    masm.jump(&invertWhenNegative);
+
+    // For sign(left) = sign(right) and len(digits(left)) != len(digits(right)),
+    // we have to consider the two cases:
+    // 1. len(digits(left)) < len(digits(right))
+    // 2. len(digits(left)) > len(digits(right))
+    //
+    // For |left| <cmp> |right| with cmp=Lt:
+    // Assume both BigInts are positive, then |left < right| is true for case 1
+    // and false for case 2. When both are negative, the result is reversed.
+    //
+    // The other comparison operators can be handled similarly.
+    //
+    // |temp0| holds the digits length of the right-hand side operand.
+    masm.bind(&compareLength);
+    masm.cmp32Set(JSOpToCondition(op, /* isSigned = */ false),
+                  Address(left, BigInt::offsetOfLength()), temp0, output);
+    masm.jump(&invertWhenNegative);
+
+    // Similar to the case above, compare the current digit to determine the
+    // overall comparison result.
+    //
+    // |temp1| points to the current digit of the left-hand side operand.
+    // |output| holds the current digit of the right-hand side operand.
+    masm.bind(&compareDigit);
+    masm.cmpPtrSet(JSOpToCondition(op, /* isSigned = */ false),
+                   Address(temp1, 0), output, output);
+
+    Label nonNegative;
+    masm.bind(&invertWhenNegative);
+    masm.branchIfBigIntIsNonNegative(left, &nonNegative);
+    masm.xor32(Imm32(1), output);
+    masm.bind(&nonNegative);
+  }
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitCompareBigIntInt32(LCompareBigIntInt32* lir) {
+  JSOp op = lir->mir()->jsop();
+  Register left = ToRegister(lir->left());
+  Register right = ToRegister(lir->right());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register output = ToRegister(lir->output());
+
+  Label ifTrue, ifFalse;
+  masm.compareBigIntAndInt32(op, left, right, temp0, temp1, &ifTrue, &ifFalse);
+
+  Label done;
+  masm.bind(&ifFalse);
+  masm.move32(Imm32(0), output);
+  masm.jump(&done);
+  masm.bind(&ifTrue);
+  masm.move32(Imm32(1), output);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitCompareBigIntDouble(LCompareBigIntDouble* lir) {
+  JSOp op = lir->mir()->jsop();
+  Register left = ToRegister(lir->left());
+  FloatRegister right = ToFloatRegister(lir->right());
+  Register output = ToRegister(lir->output());
+
+  masm.setupAlignedABICall();
+
+  // Push the operands in reverse order for JSOp::Le and JSOp::Gt:
+  // - |left <= right| is implemented as |right >= left|.
+  // - |left > right| is implemented as |right < left|.
+  if (op == JSOp::Le || op == JSOp::Gt) {
+    masm.passABIArg(right, MoveOp::DOUBLE);
+    masm.passABIArg(left);
+  } else {
+    masm.passABIArg(left);
+    masm.passABIArg(right, MoveOp::DOUBLE);
+  }
+
+  using FnBigIntNumber = bool (*)(BigInt*, double);
+  using FnNumberBigInt = bool (*)(double, BigInt*);
+  switch (op) {
+    case JSOp::Eq: {
+      masm.callWithABI<FnBigIntNumber,
+                       jit::BigIntNumberEqual<EqualityKind::Equal>>();
+      break;
+    }
+    case JSOp::Ne: {
+      masm.callWithABI<FnBigIntNumber,
+                       jit::BigIntNumberEqual<EqualityKind::NotEqual>>();
+      break;
+    }
+    case JSOp::Lt: {
+      masm.callWithABI<FnBigIntNumber,
+                       jit::BigIntNumberCompare<ComparisonKind::LessThan>>();
+      break;
+    }
+    case JSOp::Gt: {
+      masm.callWithABI<FnNumberBigInt,
+                       jit::NumberBigIntCompare<ComparisonKind::LessThan>>();
+      break;
+    }
+    case JSOp::Le: {
+      masm.callWithABI<
+          FnNumberBigInt,
+          jit::NumberBigIntCompare<ComparisonKind::GreaterThanOrEqual>>();
+      break;
+    }
+    case JSOp::Ge: {
+      masm.callWithABI<
+          FnBigIntNumber,
+          jit::BigIntNumberCompare<ComparisonKind::GreaterThanOrEqual>>();
+      break;
+    }
+    default:
+      MOZ_CRASH("unhandled op");
+  }
+
+  masm.storeCallBoolResult(output);
+}
+
+void CodeGenerator::visitCompareBigIntString(LCompareBigIntString* lir) {
+  JSOp op = lir->mir()->jsop();
+  Register left = ToRegister(lir->left());
+  Register right = ToRegister(lir->right());
+
+  // Push the operands in reverse order for JSOp::Le and JSOp::Gt:
+  // - |left <= right| is implemented as |right >= left|.
+  // - |left > right| is implemented as |right < left|.
+  if (op == JSOp::Le || op == JSOp::Gt) {
+    pushArg(left);
+    pushArg(right);
+  } else {
+    pushArg(right);
+    pushArg(left);
+  }
+
+  using FnBigIntString =
+      bool (*)(JSContext*, HandleBigInt, HandleString, bool*);
+  using FnStringBigInt =
+      bool (*)(JSContext*, HandleString, HandleBigInt, bool*);
+
+  switch (op) {
+    case JSOp::Eq: {
+      constexpr auto Equal = EqualityKind::Equal;
+      callVM<FnBigIntString, BigIntStringEqual<Equal>>(lir);
+      break;
+    }
+    case JSOp::Ne: {
+      constexpr auto NotEqual = EqualityKind::NotEqual;
+      callVM<FnBigIntString, BigIntStringEqual<NotEqual>>(lir);
+      break;
+    }
+    case JSOp::Lt: {
+      constexpr auto LessThan = ComparisonKind::LessThan;
+      callVM<FnBigIntString, BigIntStringCompare<LessThan>>(lir);
+      break;
+    }
+    case JSOp::Gt: {
+      constexpr auto LessThan = ComparisonKind::LessThan;
+      callVM<FnStringBigInt, StringBigIntCompare<LessThan>>(lir);
+      break;
+    }
+    case JSOp::Le: {
+      constexpr auto GreaterThanOrEqual = ComparisonKind::GreaterThanOrEqual;
+      callVM<FnStringBigInt, StringBigIntCompare<GreaterThanOrEqual>>(lir);
+      break;
+    }
+    case JSOp::Ge: {
+      constexpr auto GreaterThanOrEqual = ComparisonKind::GreaterThanOrEqual;
+      callVM<FnBigIntString, BigIntStringCompare<GreaterThanOrEqual>>(lir);
+      break;
+    }
+    default:
+      MOZ_CRASH("Unexpected compare op");
+  }
+}
+
+void CodeGenerator::visitIsNullOrLikeUndefinedV(LIsNullOrLikeUndefinedV* lir) {
+  MOZ_ASSERT(lir->mir()->compareType() == MCompare::Compare_Undefined ||
+             lir->mir()->compareType() == MCompare::Compare_Null);
+
+  JSOp op = lir->mir()->jsop();
+  MOZ_ASSERT(IsLooseEqualityOp(op));
+
+  const ValueOperand value = ToValue(lir, LIsNullOrLikeUndefinedV::ValueIndex);
+  Register output = ToRegister(lir->output());
+
+  auto* ool = new (alloc()) OutOfLineTestObjectWithLabels();
+  addOutOfLineCode(ool, lir->mir());
+
+  Label* nullOrLikeUndefined = ool->label1();
+  Label* notNullOrLikeUndefined = ool->label2();
+
+  {
+    ScratchTagScope tag(masm, value);
+    masm.splitTagForTest(value, tag);
+
+    masm.branchTestNull(Assembler::Equal, tag, nullOrLikeUndefined);
+    masm.branchTestUndefined(Assembler::Equal, tag, nullOrLikeUndefined);
+
+    // Check whether it's a truthy object or a falsy object that emulates
+    // undefined.
+    masm.branchTestObject(Assembler::NotEqual, tag, notNullOrLikeUndefined);
+  }
+
+  Register objreg =
+      masm.extractObject(value, ToTempUnboxRegister(lir->temp0()));
+  branchTestObjectEmulatesUndefined(objreg, nullOrLikeUndefined,
+                                    notNullOrLikeUndefined, output, ool);
+  // fall through
+
+  Label done;
+
+  // It's not null or undefined, and if it's an object it doesn't
+  // emulate undefined, so it's not like undefined.
+  masm.move32(Imm32(op == JSOp::Ne), output);
+  masm.jump(&done);
+
+  masm.bind(nullOrLikeUndefined);
+  masm.move32(Imm32(op == JSOp::Eq), output);
+
+  // Both branches meet here.
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitIsNullOrLikeUndefinedAndBranchV(
+    LIsNullOrLikeUndefinedAndBranchV* lir) {
+  MOZ_ASSERT(lir->cmpMir()->compareType() == MCompare::Compare_Undefined ||
+             lir->cmpMir()->compareType() == MCompare::Compare_Null);
+
+  JSOp op = lir->cmpMir()->jsop();
+  MOZ_ASSERT(IsLooseEqualityOp(op));
+
+  const ValueOperand value =
+      ToValue(lir, LIsNullOrLikeUndefinedAndBranchV::Value);
+
+  MBasicBlock* ifTrue = lir->ifTrue();
+  MBasicBlock* ifFalse = lir->ifFalse();
+
+  if (op == JSOp::Ne) {
+    // Swap branches.
+    std::swap(ifTrue, ifFalse);
+  }
+
+  auto* ool = new (alloc()) OutOfLineTestObject();
+  addOutOfLineCode(ool, lir->cmpMir());
+
+  Label* ifTrueLabel = getJumpLabelForBranch(ifTrue);
+  Label* ifFalseLabel = getJumpLabelForBranch(ifFalse);
+
+  {
+    ScratchTagScope tag(masm, value);
+    masm.splitTagForTest(value, tag);
+
+    masm.branchTestNull(Assembler::Equal, tag, ifTrueLabel);
+    masm.branchTestUndefined(Assembler::Equal, tag, ifTrueLabel);
+
+    masm.branchTestObject(Assembler::NotEqual, tag, ifFalseLabel);
+  }
+
+  // Objects that emulate undefined are loosely equal to null/undefined.
+  Register objreg =
+      masm.extractObject(value, ToTempUnboxRegister(lir->tempToUnbox()));
+  Register scratch = ToRegister(lir->temp());
+  testObjectEmulatesUndefined(objreg, ifTrueLabel, ifFalseLabel, scratch, ool);
+}
+
+void CodeGenerator::visitIsNullOrLikeUndefinedT(LIsNullOrLikeUndefinedT* lir) {
+  MOZ_ASSERT(lir->mir()->compareType() == MCompare::Compare_Undefined ||
+             lir->mir()->compareType() == MCompare::Compare_Null);
+  MOZ_ASSERT(lir->mir()->lhs()->type() == MIRType::Object);
+
+  JSOp op = lir->mir()->jsop();
+  MOZ_ASSERT(IsLooseEqualityOp(op), "Strict equality should have been folded");
+
+  Register objreg = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  auto* ool = new (alloc()) OutOfLineTestObjectWithLabels();
+  addOutOfLineCode(ool, lir->mir());
+
+  Label* emulatesUndefined = ool->label1();
+  Label* doesntEmulateUndefined = ool->label2();
+
+  branchTestObjectEmulatesUndefined(objreg, emulatesUndefined,
+                                    doesntEmulateUndefined, output, ool);
+
+  Label done;
+
+  masm.move32(Imm32(op == JSOp::Ne), output);
+  masm.jump(&done);
+
+  masm.bind(emulatesUndefined);
+  masm.move32(Imm32(op == JSOp::Eq), output);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitIsNullOrLikeUndefinedAndBranchT(
+    LIsNullOrLikeUndefinedAndBranchT* lir) {
+  MOZ_ASSERT(lir->cmpMir()->compareType() == MCompare::Compare_Undefined ||
+             lir->cmpMir()->compareType() == MCompare::Compare_Null);
+  MOZ_ASSERT(lir->cmpMir()->lhs()->type() == MIRType::Object);
+
+  JSOp op = lir->cmpMir()->jsop();
+  MOZ_ASSERT(IsLooseEqualityOp(op), "Strict equality should have been folded");
+
+  MBasicBlock* ifTrue = lir->ifTrue();
+  MBasicBlock* ifFalse = lir->ifFalse();
+
+  if (op == JSOp::Ne) {
+    // Swap branches.
+    std::swap(ifTrue, ifFalse);
+  }
+
+  Register input = ToRegister(lir->getOperand(0));
+
+  auto* ool = new (alloc()) OutOfLineTestObject();
+  addOutOfLineCode(ool, lir->cmpMir());
+
+  Label* ifTrueLabel = getJumpLabelForBranch(ifTrue);
+  Label* ifFalseLabel = getJumpLabelForBranch(ifFalse);
+
+  // Objects that emulate undefined are loosely equal to null/undefined.
+  Register scratch = ToRegister(lir->temp());
+  testObjectEmulatesUndefined(input, ifTrueLabel, ifFalseLabel, scratch, ool);
+}
+
+void CodeGenerator::visitIsNull(LIsNull* lir) {
+  MCompare::CompareType compareType = lir->mir()->compareType();
+  MOZ_ASSERT(compareType == MCompare::Compare_Null);
+
+  JSOp op = lir->mir()->jsop();
+  MOZ_ASSERT(IsStrictEqualityOp(op));
+
+  const ValueOperand value = ToValue(lir, LIsNull::ValueIndex);
+  Register output = ToRegister(lir->output());
+
+  Assembler::Condition cond = JSOpToCondition(compareType, op);
+  masm.testNullSet(cond, value, output);
+}
+
+void CodeGenerator::visitIsUndefined(LIsUndefined* lir) {
+  MCompare::CompareType compareType = lir->mir()->compareType();
+  MOZ_ASSERT(compareType == MCompare::Compare_Undefined);
+
+  JSOp op = lir->mir()->jsop();
+  MOZ_ASSERT(IsStrictEqualityOp(op));
+
+  const ValueOperand value = ToValue(lir, LIsUndefined::ValueIndex);
+  Register output = ToRegister(lir->output());
+
+  Assembler::Condition cond = JSOpToCondition(compareType, op);
+  masm.testUndefinedSet(cond, value, output);
+}
+
+void CodeGenerator::visitIsNullAndBranch(LIsNullAndBranch* lir) {
+  MCompare::CompareType compareType = lir->cmpMir()->compareType();
+  MOZ_ASSERT(compareType == MCompare::Compare_Null);
+
+  JSOp op = lir->cmpMir()->jsop();
+  MOZ_ASSERT(IsStrictEqualityOp(op));
+
+  const ValueOperand value = ToValue(lir, LIsNullAndBranch::Value);
+
+  Assembler::Condition cond = JSOpToCondition(compareType, op);
+  testNullEmitBranch(cond, value, lir->ifTrue(), lir->ifFalse());
+}
+
+void CodeGenerator::visitIsUndefinedAndBranch(LIsUndefinedAndBranch* lir) {
+  MCompare::CompareType compareType = lir->cmpMir()->compareType();
+  MOZ_ASSERT(compareType == MCompare::Compare_Undefined);
+
+  JSOp op = lir->cmpMir()->jsop();
+  MOZ_ASSERT(IsStrictEqualityOp(op));
+
+  const ValueOperand value = ToValue(lir, LIsUndefinedAndBranch::Value);
+
+  Assembler::Condition cond = JSOpToCondition(compareType, op);
+  testUndefinedEmitBranch(cond, value, lir->ifTrue(), lir->ifFalse());
+}
+
+void CodeGenerator::visitSameValueDouble(LSameValueDouble* lir) {
+  FloatRegister left = ToFloatRegister(lir->left());
+  FloatRegister right = ToFloatRegister(lir->right());
+  FloatRegister temp = ToFloatRegister(lir->temp0());
+  Register output = ToRegister(lir->output());
+
+  masm.sameValueDouble(left, right, temp, output);
+}
+
+void CodeGenerator::visitSameValue(LSameValue* lir) {
+  ValueOperand lhs = ToValue(lir, LSameValue::LhsIndex);
+  ValueOperand rhs = ToValue(lir, LSameValue::RhsIndex);
+  Register output = ToRegister(lir->output());
+
+  using Fn = bool (*)(JSContext*, HandleValue, HandleValue, bool*);
+  OutOfLineCode* ool =
+      oolCallVM<Fn, SameValue>(lir, ArgList(lhs, rhs), StoreRegisterTo(output));
+
+  // First check to see if the values have identical bits.
+  // This is correct for SameValue because SameValue(NaN,NaN) is true,
+  // and SameValue(0,-0) is false.
+  masm.branch64(Assembler::NotEqual, lhs.toRegister64(), rhs.toRegister64(),
+                ool->entry());
+  masm.move32(Imm32(1), output);
+
+  // If this fails, call SameValue.
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::emitConcat(LInstruction* lir, Register lhs, Register rhs,
+                               Register output) {
+  using Fn =
+      JSString* (*)(JSContext*, HandleString, HandleString, js::gc::Heap);
+  OutOfLineCode* ool = oolCallVM<Fn, ConcatStrings<CanGC>>(
+      lir, ArgList(lhs, rhs, static_cast<Imm32>(int32_t(gc::Heap::Default))),
+      StoreRegisterTo(output));
+
+  const JitRealm* jitRealm = gen->realm->jitRealm();
+  JitCode* stringConcatStub =
+      jitRealm->stringConcatStubNoBarrier(&realmStubsToReadBarrier_);
+  masm.call(stringConcatStub);
+  masm.branchTestPtr(Assembler::Zero, output, output, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitConcat(LConcat* lir) {
+  Register lhs = ToRegister(lir->lhs());
+  Register rhs = ToRegister(lir->rhs());
+
+  Register output = ToRegister(lir->output());
+
+  MOZ_ASSERT(lhs == CallTempReg0);
+  MOZ_ASSERT(rhs == CallTempReg1);
+  MOZ_ASSERT(ToRegister(lir->temp0()) == CallTempReg0);
+  MOZ_ASSERT(ToRegister(lir->temp1()) == CallTempReg1);
+  MOZ_ASSERT(ToRegister(lir->temp2()) == CallTempReg2);
+  MOZ_ASSERT(ToRegister(lir->temp3()) == CallTempReg3);
+  MOZ_ASSERT(ToRegister(lir->temp4()) == CallTempReg4);
+  MOZ_ASSERT(output == CallTempReg5);
+
+  emitConcat(lir, lhs, rhs, output);
+}
+
+static void CopyStringChars(MacroAssembler& masm, Register to, Register from,
+                            Register len, Register byteOpScratch,
+                            CharEncoding fromEncoding,
+                            CharEncoding toEncoding) {
+  // Copy |len| char16_t code units from |from| to |to|. Assumes len > 0
+  // (checked below in debug builds), and when done |to| must point to the
+  // next available char.
+
+#ifdef DEBUG
+  Label ok;
+  masm.branch32(Assembler::GreaterThan, len, Imm32(0), &ok);
+  masm.assumeUnreachable("Length should be greater than 0.");
+  masm.bind(&ok);
+#endif
+
+  MOZ_ASSERT_IF(toEncoding == CharEncoding::Latin1,
+                fromEncoding == CharEncoding::Latin1);
+
+  size_t fromWidth =
+      fromEncoding == CharEncoding::Latin1 ? sizeof(char) : sizeof(char16_t);
+  size_t toWidth =
+      toEncoding == CharEncoding::Latin1 ? sizeof(char) : sizeof(char16_t);
+
+  Label start;
+  masm.bind(&start);
+  masm.loadChar(Address(from, 0), byteOpScratch, fromEncoding);
+  masm.storeChar(byteOpScratch, Address(to, 0), toEncoding);
+  masm.addPtr(Imm32(fromWidth), from);
+  masm.addPtr(Imm32(toWidth), to);
+  masm.branchSub32(Assembler::NonZero, Imm32(1), len, &start);
+}
+
+static void CopyStringChars(MacroAssembler& masm, Register to, Register from,
+                            Register len, Register byteOpScratch,
+                            CharEncoding encoding) {
+  CopyStringChars(masm, to, from, len, byteOpScratch, encoding, encoding);
+}
+
+static void CopyStringCharsMaybeInflate(MacroAssembler& masm, Register input,
+                                        Register destChars, Register temp1,
+                                        Register temp2) {
+  // destChars is TwoByte and input is a Latin1 or TwoByte string, so we may
+  // have to inflate.
+
+  Label isLatin1, done;
+  masm.loadStringLength(input, temp1);
+  masm.branchLatin1String(input, &isLatin1);
+  {
+    masm.loadStringChars(input, temp2, CharEncoding::TwoByte);
+    masm.movePtr(temp2, input);
+    CopyStringChars(masm, destChars, input, temp1, temp2,
+                    CharEncoding::TwoByte);
+    masm.jump(&done);
+  }
+  masm.bind(&isLatin1);
+  {
+    masm.loadStringChars(input, temp2, CharEncoding::Latin1);
+    masm.movePtr(temp2, input);
+    CopyStringChars(masm, destChars, input, temp1, temp2, CharEncoding::Latin1,
+                    CharEncoding::TwoByte);
+  }
+  masm.bind(&done);
+}
+
+static void AllocateThinOrFatInlineString(MacroAssembler& masm, Register output,
+                                          Register length, Register temp,
+                                          gc::Heap initialStringHeap,
+                                          Label* failure,
+                                          CharEncoding encoding) {
+#ifdef DEBUG
+  size_t maxInlineLength;
+  if (encoding == CharEncoding::Latin1) {
+    maxInlineLength = JSFatInlineString::MAX_LENGTH_LATIN1;
+  } else {
+    maxInlineLength = JSFatInlineString::MAX_LENGTH_TWO_BYTE;
+  }
+
+  Label ok;
+  masm.branch32(Assembler::BelowOrEqual, length, Imm32(maxInlineLength), &ok);
+  masm.assumeUnreachable("string length too large to be allocated as inline");
+  masm.bind(&ok);
+#endif
+
+  size_t maxThinInlineLength;
+  if (encoding == CharEncoding::Latin1) {
+    maxThinInlineLength = JSThinInlineString::MAX_LENGTH_LATIN1;
+  } else {
+    maxThinInlineLength = JSThinInlineString::MAX_LENGTH_TWO_BYTE;
+  }
+
+  Label isFat, allocDone;
+  masm.branch32(Assembler::Above, length, Imm32(maxThinInlineLength), &isFat);
+  {
+    uint32_t flags = JSString::INIT_THIN_INLINE_FLAGS;
+    if (encoding == CharEncoding::Latin1) {
+      flags |= JSString::LATIN1_CHARS_BIT;
+    }
+    masm.newGCString(output, temp, initialStringHeap, failure);
+    masm.store32(Imm32(flags), Address(output, JSString::offsetOfFlags()));
+    masm.jump(&allocDone);
+  }
+  masm.bind(&isFat);
+  {
+    uint32_t flags = JSString::INIT_FAT_INLINE_FLAGS;
+    if (encoding == CharEncoding::Latin1) {
+      flags |= JSString::LATIN1_CHARS_BIT;
+    }
+    masm.newGCFatInlineString(output, temp, initialStringHeap, failure);
+    masm.store32(Imm32(flags), Address(output, JSString::offsetOfFlags()));
+  }
+  masm.bind(&allocDone);
+
+  // Store length.
+  masm.store32(length, Address(output, JSString::offsetOfLength()));
+}
+
+static void ConcatInlineString(MacroAssembler& masm, Register lhs, Register rhs,
+                               Register output, Register temp1, Register temp2,
+                               Register temp3, gc::Heap initialStringHeap,
+                               Label* failure, CharEncoding encoding) {
+  JitSpew(JitSpew_Codegen, "# Emitting ConcatInlineString (encoding=%s)",
+          (encoding == CharEncoding::Latin1 ? "Latin-1" : "Two-Byte"));
+
+  // State: result length in temp2.
+
+  // Ensure both strings are linear.
+  masm.branchIfRope(lhs, failure);
+  masm.branchIfRope(rhs, failure);
+
+  // Allocate a JSThinInlineString or JSFatInlineString.
+  AllocateThinOrFatInlineString(masm, output, temp2, temp1, initialStringHeap,
+                                failure, encoding);
+
+  // Load chars pointer in temp2.
+  masm.loadInlineStringCharsForStore(output, temp2);
+
+  auto copyChars = [&](Register src) {
+    if (encoding == CharEncoding::TwoByte) {
+      CopyStringCharsMaybeInflate(masm, src, temp2, temp1, temp3);
+    } else {
+      masm.loadStringLength(src, temp3);
+      masm.loadStringChars(src, temp1, CharEncoding::Latin1);
+      masm.movePtr(temp1, src);
+      CopyStringChars(masm, temp2, src, temp3, temp1, CharEncoding::Latin1);
+    }
+  };
+
+  // Copy lhs chars. Note that this advances temp2 to point to the next
+  // char. This also clobbers the lhs register.
+  copyChars(lhs);
+
+  // Copy rhs chars. Clobbers the rhs register.
+  copyChars(rhs);
+}
+
+void CodeGenerator::visitSubstr(LSubstr* lir) {
+  Register string = ToRegister(lir->string());
+  Register begin = ToRegister(lir->begin());
+  Register length = ToRegister(lir->length());
+  Register output = ToRegister(lir->output());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp2 = ToRegister(lir->temp2());
+
+  // On x86 there are not enough registers. In that case reuse the string
+  // register as temporary.
+  Register temp1 =
+      lir->temp1()->isBogusTemp() ? string : ToRegister(lir->temp1());
+
+  Label isLatin1, notInline, nonZero, nonInput, isInlinedLatin1;
+
+  // For every edge case use the C++ variant.
+  // Note: we also use this upon allocation failure in newGCString and
+  // newGCFatInlineString. To squeeze out even more performance those failures
+  // can be handled by allocate in ool code and returning to jit code to fill
+  // in all data.
+  using Fn = JSString* (*)(JSContext* cx, HandleString str, int32_t begin,
+                           int32_t len);
+  OutOfLineCode* ool = oolCallVM<Fn, SubstringKernel>(
+      lir, ArgList(string, begin, length), StoreRegisterTo(output));
+  Label* slowPath = ool->entry();
+  Label* done = ool->rejoin();
+
+  // Zero length, return emptystring.
+  masm.branchTest32(Assembler::NonZero, length, length, &nonZero);
+  const JSAtomState& names = gen->runtime->names();
+  masm.movePtr(ImmGCPtr(names.empty), output);
+  masm.jump(done);
+
+  // Substring from 0..|str.length|, return str.
+  masm.bind(&nonZero);
+  masm.branch32(Assembler::NotEqual,
+                Address(string, JSString::offsetOfLength()), length, &nonInput);
+#ifdef DEBUG
+  {
+    Label ok;
+    masm.branchTest32(Assembler::Zero, begin, begin, &ok);
+    masm.assumeUnreachable("length == str.length implies begin == 0");
+    masm.bind(&ok);
+  }
+#endif
+  masm.movePtr(string, output);
+  masm.jump(done);
+
+  // Use slow path for ropes.
+  masm.bind(&nonInput);
+  masm.branchIfRope(string, slowPath);
+
+  // Allocate either a JSThinInlineString or JSFatInlineString, or jump to
+  // notInline if we need a dependent string.
+  {
+    static_assert(JSThinInlineString::MAX_LENGTH_LATIN1 <
+                  JSFatInlineString::MAX_LENGTH_LATIN1);
+    static_assert(JSThinInlineString::MAX_LENGTH_TWO_BYTE <
+                  JSFatInlineString::MAX_LENGTH_TWO_BYTE);
+
+    // Use temp2 to store the JS(Thin|Fat)InlineString flags. This avoids having
+    // duplicate newGCString/newGCFatInlineString codegen for Latin1 vs TwoByte
+    // strings.
+
+    Label isLatin1, allocFat, allocThin, allocDone;
+    masm.branchLatin1String(string, &isLatin1);
+    {
+      masm.branch32(Assembler::Above, length,
+                    Imm32(JSFatInlineString::MAX_LENGTH_TWO_BYTE), &notInline);
+      masm.move32(Imm32(0), temp2);
+      masm.branch32(Assembler::Above, length,
+                    Imm32(JSThinInlineString::MAX_LENGTH_TWO_BYTE), &allocFat);
+      masm.jump(&allocThin);
+    }
+
+    masm.bind(&isLatin1);
+    {
+      masm.branch32(Assembler::Above, length,
+                    Imm32(JSFatInlineString::MAX_LENGTH_LATIN1), &notInline);
+      masm.move32(Imm32(JSString::LATIN1_CHARS_BIT), temp2);
+      masm.branch32(Assembler::Above, length,
+                    Imm32(JSThinInlineString::MAX_LENGTH_LATIN1), &allocFat);
+    }
+
+    masm.bind(&allocThin);
+    {
+      masm.newGCString(output, temp0, initialStringHeap(), slowPath);
+      masm.or32(Imm32(JSString::INIT_THIN_INLINE_FLAGS), temp2);
+      masm.jump(&allocDone);
+    }
+    masm.bind(&allocFat);
+    {
+      masm.newGCFatInlineString(output, temp0, initialStringHeap(), slowPath);
+      masm.or32(Imm32(JSString::INIT_FAT_INLINE_FLAGS), temp2);
+    }
+
+    masm.bind(&allocDone);
+    masm.store32(temp2, Address(output, JSString::offsetOfFlags()));
+    masm.store32(length, Address(output, JSString::offsetOfLength()));
+  }
+
+  auto initializeInlineString = [&](CharEncoding encoding) {
+    masm.loadStringChars(string, temp0, encoding);
+    masm.addToCharPtr(temp0, begin, encoding);
+    if (temp1 == string) {
+      masm.push(string);
+    }
+    masm.loadInlineStringCharsForStore(output, temp1);
+    CopyStringChars(masm, temp1, temp0, length, temp2, encoding);
+    masm.loadStringLength(output, length);
+    if (temp1 == string) {
+      masm.pop(string);
+    }
+    masm.jump(done);
+  };
+
+  masm.branchLatin1String(string, &isInlinedLatin1);
+  initializeInlineString(CharEncoding::TwoByte);
+
+  masm.bind(&isInlinedLatin1);
+  initializeInlineString(CharEncoding::Latin1);
+
+  // Handle other cases with a DependentString.
+  masm.bind(&notInline);
+  masm.newGCString(output, temp0, gen->initialStringHeap(), slowPath);
+  masm.store32(length, Address(output, JSString::offsetOfLength()));
+  masm.storeDependentStringBase(string, output);
+
+  auto initializeDependentString = [&](CharEncoding encoding) {
+    uint32_t flags = JSString::INIT_DEPENDENT_FLAGS;
+    if (encoding == CharEncoding::Latin1) {
+      flags |= JSString::LATIN1_CHARS_BIT;
+    }
+
+    masm.store32(Imm32(flags), Address(output, JSString::offsetOfFlags()));
+    masm.loadNonInlineStringChars(string, temp0, encoding);
+    masm.addToCharPtr(temp0, begin, encoding);
+    masm.storeNonInlineStringChars(temp0, output);
+    masm.jump(done);
+  };
+
+  masm.branchLatin1String(string, &isLatin1);
+  initializeDependentString(CharEncoding::TwoByte);
+
+  masm.bind(&isLatin1);
+  initializeDependentString(CharEncoding::Latin1);
+
+  masm.bind(done);
+}
+
+JitCode* JitRealm::generateStringConcatStub(JSContext* cx) {
+  JitSpew(JitSpew_Codegen, "# Emitting StringConcat stub");
+
+  TempAllocator temp(&cx->tempLifoAlloc());
+  JitContext jcx(cx);
+  StackMacroAssembler masm(cx, temp);
+  AutoCreatedBy acb(masm, "JitRealm::generateStringConcatStub");
+
+  Register lhs = CallTempReg0;
+  Register rhs = CallTempReg1;
+  Register temp1 = CallTempReg2;
+  Register temp2 = CallTempReg3;
+  Register temp3 = CallTempReg4;
+  Register output = CallTempReg5;
+
+  Label failure;
+#ifdef JS_USE_LINK_REGISTER
+  masm.pushReturnAddress();
+#endif
+  masm.Push(FramePointer);
+  masm.moveStackPtrTo(FramePointer);
+
+  // If lhs is empty, return rhs.
+  Label leftEmpty;
+  masm.loadStringLength(lhs, temp1);
+  masm.branchTest32(Assembler::Zero, temp1, temp1, &leftEmpty);
+
+  // If rhs is empty, return lhs.
+  Label rightEmpty;
+  masm.loadStringLength(rhs, temp2);
+  masm.branchTest32(Assembler::Zero, temp2, temp2, &rightEmpty);
+
+  masm.add32(temp1, temp2);
+
+  // Check if we can use a JSInlineString. The result is a Latin1 string if
+  // lhs and rhs are both Latin1, so we AND the flags.
+  Label isInlineTwoByte, isInlineLatin1;
+  masm.load32(Address(lhs, JSString::offsetOfFlags()), temp1);
+  masm.and32(Address(rhs, JSString::offsetOfFlags()), temp1);
+
+  Label isLatin1, notInline;
+  masm.branchTest32(Assembler::NonZero, temp1,
+                    Imm32(JSString::LATIN1_CHARS_BIT), &isLatin1);
+  {
+    masm.branch32(Assembler::BelowOrEqual, temp2,
+                  Imm32(JSFatInlineString::MAX_LENGTH_TWO_BYTE),
+                  &isInlineTwoByte);
+    masm.jump(&notInline);
+  }
+  masm.bind(&isLatin1);
+  {
+    masm.branch32(Assembler::BelowOrEqual, temp2,
+                  Imm32(JSFatInlineString::MAX_LENGTH_LATIN1), &isInlineLatin1);
+  }
+  masm.bind(&notInline);
+
+  // Keep AND'ed flags in temp1.
+
+  // Ensure result length <= JSString::MAX_LENGTH.
+  masm.branch32(Assembler::Above, temp2, Imm32(JSString::MAX_LENGTH), &failure);
+
+  // Allocate a new rope, guaranteed to be in the nursery if initialStringHeap
+  // == gc::Heap::Default. (As a result, no post barriers are needed below.)
+  masm.newGCString(output, temp3, initialStringHeap, &failure);
+
+  // Store rope length and flags. temp1 still holds the result of AND'ing the
+  // lhs and rhs flags, so we just have to clear the other flags to get our rope
+  // flags (Latin1 if both lhs and rhs are Latin1).
+  static_assert(JSString::INIT_ROPE_FLAGS == 0,
+                "Rope type flags must have no bits set");
+  masm.and32(Imm32(JSString::LATIN1_CHARS_BIT), temp1);
+  masm.store32(temp1, Address(output, JSString::offsetOfFlags()));
+  masm.store32(temp2, Address(output, JSString::offsetOfLength()));
+
+  // Store left and right nodes.
+  masm.storeRopeChildren(lhs, rhs, output);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  masm.bind(&leftEmpty);
+  masm.mov(rhs, output);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  masm.bind(&rightEmpty);
+  masm.mov(lhs, output);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  masm.bind(&isInlineTwoByte);
+  ConcatInlineString(masm, lhs, rhs, output, temp1, temp2, temp3,
+                     initialStringHeap, &failure, CharEncoding::TwoByte);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  masm.bind(&isInlineLatin1);
+  ConcatInlineString(masm, lhs, rhs, output, temp1, temp2, temp3,
+                     initialStringHeap, &failure, CharEncoding::Latin1);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  masm.pop(temp2);
+  masm.pop(temp1);
+
+  masm.bind(&failure);
+  masm.movePtr(ImmPtr(nullptr), output);
+  masm.pop(FramePointer);
+  masm.ret();
+
+  Linker linker(masm);
+  JitCode* code = linker.newCode(cx, CodeKind::Other);
+
+  CollectPerfSpewerJitCodeProfile(code, "StringConcatStub");
+#ifdef MOZ_VTUNE
+  vtune::MarkStub(code, "StringConcatStub");
+#endif
+
+  return code;
+}
+
+void JitRuntime::generateFreeStub(MacroAssembler& masm) {
+  AutoCreatedBy acb(masm, "JitRuntime::generateFreeStub");
+
+  const Register regSlots = CallTempReg0;
+
+  freeStubOffset_ = startTrampolineCode(masm);
+
+#ifdef JS_USE_LINK_REGISTER
+  masm.pushReturnAddress();
+#endif
+  AllocatableRegisterSet regs(RegisterSet::Volatile());
+  regs.takeUnchecked(regSlots);
+  LiveRegisterSet save(regs.asLiveSet());
+  masm.PushRegsInMask(save);
+
+  const Register regTemp = regs.takeAnyGeneral();
+  MOZ_ASSERT(regTemp != regSlots);
+
+  using Fn = void (*)(void* p);
+  masm.setupUnalignedABICall(regTemp);
+  masm.passABIArg(regSlots);
+  masm.callWithABI<Fn, js_free>(MoveOp::GENERAL,
+                                CheckUnsafeCallWithABI::DontCheckOther);
+
+  masm.PopRegsInMask(save);
+
+  masm.ret();
+}
+
+void JitRuntime::generateLazyLinkStub(MacroAssembler& masm) {
+  AutoCreatedBy acb(masm, "JitRuntime::generateLazyLinkStub");
+
+  lazyLinkStubOffset_ = startTrampolineCode(masm);
+
+#ifdef JS_USE_LINK_REGISTER
+  masm.pushReturnAddress();
+#endif
+  masm.Push(FramePointer);
+  masm.moveStackPtrTo(FramePointer);
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::Volatile());
+  Register temp0 = regs.takeAny();
+  Register temp1 = regs.takeAny();
+  Register temp2 = regs.takeAny();
+
+  masm.loadJSContext(temp0);
+  masm.enterFakeExitFrame(temp0, temp2, ExitFrameType::LazyLink);
+  masm.moveStackPtrTo(temp1);
+
+  using Fn = uint8_t* (*)(JSContext* cx, LazyLinkExitFrameLayout* frame);
+  masm.setupUnalignedABICall(temp2);
+  masm.passABIArg(temp0);
+  masm.passABIArg(temp1);
+  masm.callWithABI<Fn, LazyLinkTopActivation>(
+      MoveOp::GENERAL, CheckUnsafeCallWithABI::DontCheckHasExitFrame);
+
+  // Discard exit frame and restore frame pointer.
+  masm.leaveExitFrame(0);
+  masm.pop(FramePointer);
+
+#ifdef JS_USE_LINK_REGISTER
+  // Restore the return address such that the emitPrologue function of the
+  // CodeGenerator can push it back on the stack with pushReturnAddress.
+  masm.popReturnAddress();
+#endif
+  masm.jump(ReturnReg);
+}
+
+void JitRuntime::generateInterpreterStub(MacroAssembler& masm) {
+  AutoCreatedBy acb(masm, "JitRuntime::generateInterpreterStub");
+
+  interpreterStubOffset_ = startTrampolineCode(masm);
+
+#ifdef JS_USE_LINK_REGISTER
+  masm.pushReturnAddress();
+#endif
+  masm.Push(FramePointer);
+  masm.moveStackPtrTo(FramePointer);
+
+  AllocatableGeneralRegisterSet regs(GeneralRegisterSet::Volatile());
+  Register temp0 = regs.takeAny();
+  Register temp1 = regs.takeAny();
+  Register temp2 = regs.takeAny();
+
+  masm.loadJSContext(temp0);
+  masm.enterFakeExitFrame(temp0, temp2, ExitFrameType::InterpreterStub);
+  masm.moveStackPtrTo(temp1);
+
+  using Fn = bool (*)(JSContext* cx, InterpreterStubExitFrameLayout* frame);
+  masm.setupUnalignedABICall(temp2);
+  masm.passABIArg(temp0);
+  masm.passABIArg(temp1);
+  masm.callWithABI<Fn, InvokeFromInterpreterStub>(
+      MoveOp::GENERAL, CheckUnsafeCallWithABI::DontCheckHasExitFrame);
+
+  masm.branchIfFalseBool(ReturnReg, masm.failureLabel());
+
+  // Discard exit frame and restore frame pointer.
+  masm.leaveExitFrame(0);
+  masm.pop(FramePointer);
+
+  // InvokeFromInterpreterStub stores the return value in argv[0], where the
+  // caller stored |this|. Subtract |sizeof(void*)| for the frame pointer we
+  // just popped.
+  masm.loadValue(Address(masm.getStackPointer(),
+                         JitFrameLayout::offsetOfThis() - sizeof(void*)),
+                 JSReturnOperand);
+  masm.ret();
+}
+
+void JitRuntime::generateDoubleToInt32ValueStub(MacroAssembler& masm) {
+  AutoCreatedBy acb(masm, "JitRuntime::generateDoubleToInt32ValueStub");
+  doubleToInt32ValueStubOffset_ = startTrampolineCode(masm);
+
+  Label done;
+  masm.branchTestDouble(Assembler::NotEqual, R0, &done);
+
+  masm.unboxDouble(R0, FloatReg0);
+  masm.convertDoubleToInt32(FloatReg0, R1.scratchReg(), &done,
+                            /* negativeZeroCheck = */ false);
+  masm.tagValue(JSVAL_TYPE_INT32, R1.scratchReg(), R0);
+
+  masm.bind(&done);
+  masm.abiret();
+}
+
+void CodeGenerator::visitLinearizeForCharAccess(LLinearizeForCharAccess* lir) {
+  Register str = ToRegister(lir->str());
+  Register index = ToRegister(lir->index());
+  Register output = ToRegister(lir->output());
+
+  using Fn = JSLinearString* (*)(JSContext*, JSString*);
+  auto* ool = oolCallVM<Fn, jit::LinearizeForCharAccess>(
+      lir, ArgList(str), StoreRegisterTo(output));
+
+  masm.branchIfNotCanLoadStringChar(str, index, output, ool->entry());
+
+  masm.movePtr(str, output);
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCharCodeAt(LCharCodeAt* lir) {
+  Register str = ToRegister(lir->str());
+  Register index = ToRegister(lir->index());
+  Register output = ToRegister(lir->output());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  using Fn = bool (*)(JSContext*, HandleString, int32_t, uint32_t*);
+  OutOfLineCode* ool = oolCallVM<Fn, jit::CharCodeAt>(lir, ArgList(str, index),
+                                                      StoreRegisterTo(output));
+  masm.loadStringChar(str, index, output, temp0, temp1, ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCharCodeAtMaybeOutOfBounds(
+    LCharCodeAtMaybeOutOfBounds* lir) {
+  Register str = ToRegister(lir->str());
+  Register index = ToRegister(lir->index());
+  ValueOperand output = ToOutValue(lir);
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  using Fn = bool (*)(JSContext*, HandleString, int32_t, uint32_t*);
+  auto* ool = oolCallVM<Fn, jit::CharCodeAt>(
+      lir, ArgList(str, index), StoreRegisterTo(output.scratchReg()));
+
+  // Return NaN for out-of-bounds access.
+  Label done;
+  masm.moveValue(JS::NaNValue(), output);
+
+  masm.spectreBoundsCheck32(index, Address(str, JSString::offsetOfLength()),
+                            temp0, &done);
+
+  masm.loadStringChar(str, index, output.scratchReg(), temp0, temp1,
+                      ool->entry());
+  masm.bind(ool->rejoin());
+
+  masm.tagValue(JSVAL_TYPE_INT32, output.scratchReg(), output);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitCharAtMaybeOutOfBounds(LCharAtMaybeOutOfBounds* lir) {
+  Register str = ToRegister(lir->str());
+  Register index = ToRegister(lir->index());
+  Register output = ToRegister(lir->output());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  using Fn1 = bool (*)(JSContext*, HandleString, int32_t, uint32_t*);
+  auto* oolLoadChar = oolCallVM<Fn1, jit::CharCodeAt>(lir, ArgList(str, index),
+                                                      StoreRegisterTo(output));
+
+  using Fn2 = JSLinearString* (*)(JSContext*, int32_t);
+  auto* oolFromCharCode = oolCallVM<Fn2, jit::StringFromCharCode>(
+      lir, ArgList(output), StoreRegisterTo(output));
+
+  // Return the empty string for out-of-bounds access.
+  const JSAtomState& names = gen->runtime->names();
+  masm.movePtr(ImmGCPtr(names.empty), output);
+
+  masm.spectreBoundsCheck32(index, Address(str, JSString::offsetOfLength()),
+                            temp0, oolFromCharCode->rejoin());
+
+  masm.loadStringChar(str, index, output, temp0, temp1, oolLoadChar->entry());
+  masm.bind(oolLoadChar->rejoin());
+
+  // OOL path if code >= UNIT_STATIC_LIMIT.
+  masm.boundsCheck32PowerOfTwo(output, StaticStrings::UNIT_STATIC_LIMIT,
+                               oolFromCharCode->entry());
+
+  masm.movePtr(ImmPtr(&gen->runtime->staticStrings().unitStaticTable), temp0);
+  masm.loadPtr(BaseIndex(temp0, output, ScalePointer), output);
+
+  masm.bind(oolFromCharCode->rejoin());
+}
+
+void CodeGenerator::visitFromCharCode(LFromCharCode* lir) {
+  Register code = ToRegister(lir->code());
+  Register output = ToRegister(lir->output());
+
+  using Fn = JSLinearString* (*)(JSContext*, int32_t);
+  OutOfLineCode* ool = oolCallVM<Fn, jit::StringFromCharCode>(
+      lir, ArgList(code), StoreRegisterTo(output));
+
+  // OOL path if code >= UNIT_STATIC_LIMIT.
+  masm.boundsCheck32PowerOfTwo(code, StaticStrings::UNIT_STATIC_LIMIT,
+                               ool->entry());
+
+  masm.movePtr(ImmPtr(&gen->runtime->staticStrings().unitStaticTable), output);
+  masm.loadPtr(BaseIndex(output, code, ScalePointer), output);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitFromCodePoint(LFromCodePoint* lir) {
+  Register codePoint = ToRegister(lir->codePoint());
+  Register output = ToRegister(lir->output());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  LSnapshot* snapshot = lir->snapshot();
+
+  // The OOL path is only taken when we can't allocate the inline string.
+  using Fn = JSString* (*)(JSContext*, int32_t);
+  OutOfLineCode* ool = oolCallVM<Fn, jit::StringFromCodePoint>(
+      lir, ArgList(codePoint), StoreRegisterTo(output));
+
+  Label isTwoByte;
+  Label* done = ool->rejoin();
+
+  static_assert(
+      StaticStrings::UNIT_STATIC_LIMIT - 1 == JSString::MAX_LATIN1_CHAR,
+      "Latin-1 strings can be loaded from static strings");
+  masm.boundsCheck32PowerOfTwo(codePoint, StaticStrings::UNIT_STATIC_LIMIT,
+                               &isTwoByte);
+  {
+    masm.movePtr(ImmPtr(&gen->runtime->staticStrings().unitStaticTable),
+                 output);
+    masm.loadPtr(BaseIndex(output, codePoint, ScalePointer), output);
+    masm.jump(done);
+  }
+  masm.bind(&isTwoByte);
+  {
+    // Use a bailout if the input is not a valid code point, because
+    // MFromCodePoint is movable and it'd be observable when a moved
+    // fromCodePoint throws an exception before its actual call site.
+    bailoutCmp32(Assembler::Above, codePoint, Imm32(unicode::NonBMPMax),
+                 snapshot);
+
+    // Allocate a JSThinInlineString.
+    {
+      static_assert(JSThinInlineString::MAX_LENGTH_TWO_BYTE >= 2,
+                    "JSThinInlineString can hold a supplementary code point");
+
+      uint32_t flags = JSString::INIT_THIN_INLINE_FLAGS;
+      masm.newGCString(output, temp0, gen->initialStringHeap(), ool->entry());
+      masm.store32(Imm32(flags), Address(output, JSString::offsetOfFlags()));
+    }
+
+    Label isSupplementary;
+    masm.branch32(Assembler::AboveOrEqual, codePoint, Imm32(unicode::NonBMPMin),
+                  &isSupplementary);
+    {
+      // Store length.
+      masm.store32(Imm32(1), Address(output, JSString::offsetOfLength()));
+
+      // Load chars pointer in temp0.
+      masm.loadInlineStringCharsForStore(output, temp0);
+
+      masm.store16(codePoint, Address(temp0, 0));
+
+      masm.jump(done);
+    }
+    masm.bind(&isSupplementary);
+    {
+      // Store length.
+      masm.store32(Imm32(2), Address(output, JSString::offsetOfLength()));
+
+      // Load chars pointer in temp0.
+      masm.loadInlineStringCharsForStore(output, temp0);
+
+      // Inlined unicode::LeadSurrogate(uint32_t).
+      masm.move32(codePoint, temp1);
+      masm.rshift32(Imm32(10), temp1);
+      masm.add32(Imm32(unicode::LeadSurrogateMin - (unicode::NonBMPMin >> 10)),
+                 temp1);
+
+      masm.store16(temp1, Address(temp0, 0));
+
+      // Inlined unicode::TrailSurrogate(uint32_t).
+      masm.move32(codePoint, temp1);
+      masm.and32(Imm32(0x3FF), temp1);
+      masm.or32(Imm32(unicode::TrailSurrogateMin), temp1);
+
+      masm.store16(temp1, Address(temp0, sizeof(char16_t)));
+    }
+  }
+
+  masm.bind(done);
+}
+
+void CodeGenerator::visitStringIndexOf(LStringIndexOf* lir) {
+  pushArg(ToRegister(lir->searchString()));
+  pushArg(ToRegister(lir->string()));
+
+  using Fn = bool (*)(JSContext*, HandleString, HandleString, int32_t*);
+  callVM<Fn, js::StringIndexOf>(lir);
+}
+
+void CodeGenerator::visitStringStartsWith(LStringStartsWith* lir) {
+  pushArg(ToRegister(lir->searchString()));
+  pushArg(ToRegister(lir->string()));
+
+  using Fn = bool (*)(JSContext*, HandleString, HandleString, bool*);
+  callVM<Fn, js::StringStartsWith>(lir);
+}
+
+void CodeGenerator::visitStringStartsWithInline(LStringStartsWithInline* lir) {
+  Register string = ToRegister(lir->string());
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  const JSLinearString* searchString = lir->searchString();
+
+  size_t length = searchString->length();
+  MOZ_ASSERT(length > 0);
+
+  using Fn = bool (*)(JSContext*, HandleString, HandleString, bool*);
+  auto* ool = oolCallVM<Fn, js::StringStartsWith>(
+      lir, ArgList(string, ImmGCPtr(searchString)), StoreRegisterTo(output));
+
+  masm.move32(Imm32(0), output);
+
+  // Can't be a prefix when the string is smaller than the search string.
+  masm.branch32(Assembler::Below, Address(string, JSString::offsetOfLength()),
+                Imm32(length), ool->rejoin());
+
+  // Unwind ropes at the start if possible.
+  Label compare;
+  masm.movePtr(string, temp);
+  masm.branchIfNotRope(temp, &compare);
+
+  Label unwindRope;
+  masm.bind(&unwindRope);
+  masm.loadRopeLeftChild(temp, output);
+  masm.movePtr(output, temp);
+
+  // If the left child is smaller than the search string, jump into the VM to
+  // linearize the string.
+  masm.branch32(Assembler::Below, Address(temp, JSString::offsetOfLength()),
+                Imm32(length), ool->entry());
+
+  // Otherwise keep unwinding ropes.
+  masm.branchIfRope(temp, &unwindRope);
+
+  masm.bind(&compare);
+
+  // If operands point to the same instance, it's trivially a prefix.
+  Label notPointerEqual;
+  masm.branchPtr(Assembler::NotEqual, temp, ImmGCPtr(searchString),
+                 &notPointerEqual);
+  masm.move32(Imm32(1), output);
+  masm.jump(ool->rejoin());
+  masm.bind(&notPointerEqual);
+
+  if (searchString->hasTwoByteChars()) {
+    // Pure two-byte strings can't be a prefix of Latin-1 strings.
+    JS::AutoCheckCannotGC nogc;
+    if (!mozilla::IsUtf16Latin1(searchString->twoByteRange(nogc))) {
+      Label compareChars;
+      masm.branchTwoByteString(temp, &compareChars);
+      masm.move32(Imm32(0), output);
+      masm.jump(ool->rejoin());
+      masm.bind(&compareChars);
+    }
+  }
+
+  // Otherwise start comparing character by character.
+  CompareCharacters(masm, temp, searchString, output, JSOp::Eq,
+                    CompareDirection::Forward, ool->rejoin(), ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitStringEndsWith(LStringEndsWith* lir) {
+  pushArg(ToRegister(lir->searchString()));
+  pushArg(ToRegister(lir->string()));
+
+  using Fn = bool (*)(JSContext*, HandleString, HandleString, bool*);
+  callVM<Fn, js::StringEndsWith>(lir);
+}
+
+void CodeGenerator::visitStringEndsWithInline(LStringEndsWithInline* lir) {
+  Register string = ToRegister(lir->string());
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  const JSLinearString* searchString = lir->searchString();
+
+  size_t length = searchString->length();
+  MOZ_ASSERT(length > 0);
+
+  using Fn = bool (*)(JSContext*, HandleString, HandleString, bool*);
+  auto* ool = oolCallVM<Fn, js::StringEndsWith>(
+      lir, ArgList(string, ImmGCPtr(searchString)), StoreRegisterTo(output));
+
+  masm.move32(Imm32(0), output);
+
+  // Can't be a suffix when the string is smaller than the search string.
+  masm.branch32(Assembler::Below, Address(string, JSString::offsetOfLength()),
+                Imm32(length), ool->rejoin());
+
+  // Unwind ropes at the end if possible.
+  Label compare;
+  masm.movePtr(string, temp);
+  masm.branchIfNotRope(temp, &compare);
+
+  Label unwindRope;
+  masm.bind(&unwindRope);
+  masm.loadRopeRightChild(temp, output);
+  masm.movePtr(output, temp);
+
+  // If the right child is smaller than the search string, jump into the VM to
+  // linearize the string.
+  masm.branch32(Assembler::Below, Address(temp, JSString::offsetOfLength()),
+                Imm32(length), ool->entry());
+
+  // Otherwise keep unwinding ropes.
+  masm.branchIfRope(temp, &unwindRope);
+
+  masm.bind(&compare);
+
+  // If operands point to the same instance, it's trivially a suffix.
+  Label notPointerEqual;
+  masm.branchPtr(Assembler::NotEqual, temp, ImmGCPtr(searchString),
+                 &notPointerEqual);
+  masm.move32(Imm32(1), output);
+  masm.jump(ool->rejoin());
+  masm.bind(&notPointerEqual);
+
+  if (searchString->hasTwoByteChars()) {
+    // Pure two-byte strings can't be a suffix of Latin-1 strings.
+    JS::AutoCheckCannotGC nogc;
+    if (!mozilla::IsUtf16Latin1(searchString->twoByteRange(nogc))) {
+      Label compareChars;
+      masm.branchTwoByteString(temp, &compareChars);
+      masm.move32(Imm32(0), output);
+      masm.jump(ool->rejoin());
+      masm.bind(&compareChars);
+    }
+  }
+
+  // Otherwise start comparing character by character.
+  CompareCharacters(masm, temp, searchString, output, JSOp::Eq,
+                    CompareDirection::Backward, ool->rejoin(), ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitStringToLowerCase(LStringToLowerCase* lir) {
+  Register string = ToRegister(lir->string());
+  Register output = ToRegister(lir->output());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+
+  // On x86 there are not enough registers. In that case reuse the string
+  // register as a temporary.
+  Register temp3 =
+      lir->temp3()->isBogusTemp() ? string : ToRegister(lir->temp3());
+  Register temp4 = ToRegister(lir->temp4());
+
+  using Fn = JSString* (*)(JSContext*, HandleString);
+  OutOfLineCode* ool = oolCallVM<Fn, js::StringToLowerCase>(
+      lir, ArgList(string), StoreRegisterTo(output));
+
+  // Take the slow path if the string isn't a linear Latin-1 string.
+  Imm32 linearLatin1Bits(JSString::LINEAR_BIT | JSString::LATIN1_CHARS_BIT);
+  Register flags = temp0;
+  masm.load32(Address(string, JSString::offsetOfFlags()), flags);
+  masm.and32(linearLatin1Bits, flags);
+  masm.branch32(Assembler::NotEqual, flags, linearLatin1Bits, ool->entry());
+
+  Register length = temp0;
+  masm.loadStringLength(string, length);
+
+  // Return the input if it's the empty string.
+  Label notEmptyString;
+  masm.branch32(Assembler::NotEqual, length, Imm32(0), &notEmptyString);
+  {
+    masm.movePtr(string, output);
+    masm.jump(ool->rejoin());
+  }
+  masm.bind(&notEmptyString);
+
+  Register inputChars = temp1;
+  masm.loadStringChars(string, inputChars, CharEncoding::Latin1);
+
+  Register toLowerCaseTable = temp2;
+  masm.movePtr(ImmPtr(unicode::latin1ToLowerCaseTable), toLowerCaseTable);
+
+  // Single element strings can be directly retrieved from static strings cache.
+  Label notSingleElementString;
+  masm.branch32(Assembler::NotEqual, length, Imm32(1), &notSingleElementString);
+  {
+    Register current = temp4;
+
+    masm.loadChar(Address(inputChars, 0), current, CharEncoding::Latin1);
+    masm.load8ZeroExtend(BaseIndex(toLowerCaseTable, current, TimesOne),
+                         current);
+    masm.movePtr(ImmPtr(&gen->runtime->staticStrings().unitStaticTable),
+                 output);
+    masm.loadPtr(BaseIndex(output, current, ScalePointer), output);
+
+    masm.jump(ool->rejoin());
+  }
+  masm.bind(&notSingleElementString);
+
+  // Use the OOL-path when the string is too long. This prevents scanning long
+  // strings which have upper case characters only near the end a second time in
+  // the VM.
+  constexpr int32_t MaxInlineLength = 64;
+  masm.branch32(Assembler::Above, length, Imm32(MaxInlineLength), ool->entry());
+
+  {
+    // Check if there are any characters which need to be converted.
+    //
+    // This extra loop gives a small performance improvement for strings which
+    // are already lower cased and lets us avoid calling into the runtime for
+    // non-inline, all lower case strings. But more importantly it avoids
+    // repeated inline allocation failures:
+    // |AllocateThinOrFatInlineString| below takes the OOL-path and calls the
+    // |js::StringToLowerCase| runtime function when the result string can't be
+    // allocated inline. And |js::StringToLowerCase| directly returns the input
+    // string when no characters need to be converted. That means it won't
+    // trigger GC to clear up the free nursery space, so the next toLowerCase()
+    // call will again fail to inline allocate the result string.
+    Label hasUpper;
+    {
+      Register checkInputChars = output;
+      masm.movePtr(inputChars, checkInputChars);
+
+      Register current = temp4;
+
+      Label start;
+      masm.bind(&start);
+      masm.loadChar(Address(checkInputChars, 0), current, CharEncoding::Latin1);
+      masm.branch8(Assembler::NotEqual,
+                   BaseIndex(toLowerCaseTable, current, TimesOne), current,
+                   &hasUpper);
+      masm.addPtr(Imm32(sizeof(Latin1Char)), checkInputChars);
+      masm.branchSub32(Assembler::NonZero, Imm32(1), length, &start);
+
+      // Input is already in lower case.
+      masm.movePtr(string, output);
+      masm.jump(ool->rejoin());
+    }
+    masm.bind(&hasUpper);
+
+    // |length| was clobbered above, reload.
+    masm.loadStringLength(string, length);
+
+    // Call into the runtime when we can't create an inline string.
+    masm.branch32(Assembler::Above, length,
+                  Imm32(JSFatInlineString::MAX_LENGTH_LATIN1), ool->entry());
+
+    AllocateThinOrFatInlineString(masm, output, length, temp4,
+                                  initialStringHeap(), ool->entry(),
+                                  CharEncoding::Latin1);
+
+    if (temp3 == string) {
+      masm.push(string);
+    }
+
+    Register outputChars = temp3;
+    masm.loadInlineStringCharsForStore(output, outputChars);
+
+    {
+      Register current = temp4;
+
+      Label start;
+      masm.bind(&start);
+      masm.loadChar(Address(inputChars, 0), current, CharEncoding::Latin1);
+      masm.load8ZeroExtend(BaseIndex(toLowerCaseTable, current, TimesOne),
+                           current);
+      masm.storeChar(current, Address(outputChars, 0), CharEncoding::Latin1);
+      masm.addPtr(Imm32(sizeof(Latin1Char)), inputChars);
+      masm.addPtr(Imm32(sizeof(Latin1Char)), outputChars);
+      masm.branchSub32(Assembler::NonZero, Imm32(1), length, &start);
+    }
+
+    if (temp3 == string) {
+      masm.pop(string);
+    }
+  }
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitStringToUpperCase(LStringToUpperCase* lir) {
+  pushArg(ToRegister(lir->string()));
+
+  using Fn = JSString* (*)(JSContext*, HandleString);
+  callVM<Fn, js::StringToUpperCase>(lir);
+}
+
+void CodeGenerator::visitStringSplit(LStringSplit* lir) {
+  pushArg(Imm32(INT32_MAX));
+  pushArg(ToRegister(lir->separator()));
+  pushArg(ToRegister(lir->string()));
+
+  using Fn = ArrayObject* (*)(JSContext*, HandleString, HandleString, uint32_t);
+  callVM<Fn, js::StringSplitString>(lir);
+}
+
+void CodeGenerator::visitInitializedLength(LInitializedLength* lir) {
+  Address initLength(ToRegister(lir->elements()),
+                     ObjectElements::offsetOfInitializedLength());
+  masm.load32(initLength, ToRegister(lir->output()));
+}
+
+void CodeGenerator::visitSetInitializedLength(LSetInitializedLength* lir) {
+  Address initLength(ToRegister(lir->elements()),
+                     ObjectElements::offsetOfInitializedLength());
+  SetLengthFromIndex(masm, lir->index(), initLength);
+}
+
+void CodeGenerator::visitNotBI(LNotBI* lir) {
+  Register input = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  masm.cmp32Set(Assembler::Equal, Address(input, BigInt::offsetOfLength()),
+                Imm32(0), output);
+}
+
+void CodeGenerator::visitNotO(LNotO* lir) {
+  auto* ool = new (alloc()) OutOfLineTestObjectWithLabels();
+  addOutOfLineCode(ool, lir->mir());
+
+  Label* ifEmulatesUndefined = ool->label1();
+  Label* ifDoesntEmulateUndefined = ool->label2();
+
+  Register objreg = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+  branchTestObjectEmulatesUndefined(objreg, ifEmulatesUndefined,
+                                    ifDoesntEmulateUndefined, output, ool);
+  // fall through
+
+  Label join;
+
+  masm.move32(Imm32(0), output);
+  masm.jump(&join);
+
+  masm.bind(ifEmulatesUndefined);
+  masm.move32(Imm32(1), output);
+
+  masm.bind(&join);
+}
+
+void CodeGenerator::visitNotV(LNotV* lir) {
+  auto* ool = new (alloc()) OutOfLineTestObjectWithLabels();
+  addOutOfLineCode(ool, lir->mir());
+
+  Label* ifTruthy = ool->label1();
+  Label* ifFalsy = ool->label2();
+
+  ValueOperand input = ToValue(lir, LNotV::InputIndex);
+  Register tempToUnbox = ToTempUnboxRegister(lir->temp1());
+  FloatRegister floatTemp = ToFloatRegister(lir->temp0());
+  Register output = ToRegister(lir->output());
+  const TypeDataList& observedTypes = lir->mir()->observedTypes();
+
+  testValueTruthy(input, tempToUnbox, output, floatTemp, observedTypes,
+                  ifTruthy, ifFalsy, ool);
+
+  Label join;
+
+  // Note that the testValueTruthy call above may choose to fall through
+  // to ifTruthy instead of branching there.
+  masm.bind(ifTruthy);
+  masm.move32(Imm32(0), output);
+  masm.jump(&join);
+
+  masm.bind(ifFalsy);
+  masm.move32(Imm32(1), output);
+
+  // both branches meet here.
+  masm.bind(&join);
+}
+
+void CodeGenerator::visitBoundsCheck(LBoundsCheck* lir) {
+  const LAllocation* index = lir->index();
+  const LAllocation* length = lir->length();
+  LSnapshot* snapshot = lir->snapshot();
+
+  MIRType type = lir->mir()->type();
+
+  auto bailoutCmp = [&](Assembler::Condition cond, auto lhs, auto rhs) {
+    if (type == MIRType::Int32) {
+      bailoutCmp32(cond, lhs, rhs, snapshot);
+    } else {
+      MOZ_ASSERT(type == MIRType::IntPtr);
+      bailoutCmpPtr(cond, lhs, rhs, snapshot);
+    }
+  };
+
+  auto bailoutCmpConstant = [&](Assembler::Condition cond, auto lhs,
+                                int32_t rhs) {
+    if (type == MIRType::Int32) {
+      bailoutCmp32(cond, lhs, Imm32(rhs), snapshot);
+    } else {
+      MOZ_ASSERT(type == MIRType::IntPtr);
+      bailoutCmpPtr(cond, lhs, ImmWord(rhs), snapshot);
+    }
+  };
+
+  if (index->isConstant()) {
+    // Use uint32 so that the comparison is unsigned.
+    uint32_t idx = ToInt32(index);
+    if (length->isConstant()) {
+      uint32_t len = ToInt32(lir->length());
+      if (idx < len) {
+        return;
+      }
+      bailout(snapshot);
+      return;
+    }
+
+    if (length->isRegister()) {
+      bailoutCmpConstant(Assembler::BelowOrEqual, ToRegister(length), idx);
+    } else {
+      bailoutCmpConstant(Assembler::BelowOrEqual, ToAddress(length), idx);
+    }
+    return;
+  }
+
+  Register indexReg = ToRegister(index);
+  if (length->isConstant()) {
+    bailoutCmpConstant(Assembler::AboveOrEqual, indexReg, ToInt32(length));
+  } else if (length->isRegister()) {
+    bailoutCmp(Assembler::BelowOrEqual, ToRegister(length), indexReg);
+  } else {
+    bailoutCmp(Assembler::BelowOrEqual, ToAddress(length), indexReg);
+  }
+}
+
+void CodeGenerator::visitBoundsCheckRange(LBoundsCheckRange* lir) {
+  int32_t min = lir->mir()->minimum();
+  int32_t max = lir->mir()->maximum();
+  MOZ_ASSERT(max >= min);
+
+  LSnapshot* snapshot = lir->snapshot();
+  MIRType type = lir->mir()->type();
+
+  const LAllocation* length = lir->length();
+  Register temp = ToRegister(lir->getTemp(0));
+
+  auto bailoutCmp = [&](Assembler::Condition cond, auto lhs, auto rhs) {
+    if (type == MIRType::Int32) {
+      bailoutCmp32(cond, lhs, rhs, snapshot);
+    } else {
+      MOZ_ASSERT(type == MIRType::IntPtr);
+      bailoutCmpPtr(cond, lhs, rhs, snapshot);
+    }
+  };
+
+  auto bailoutCmpConstant = [&](Assembler::Condition cond, auto lhs,
+                                int32_t rhs) {
+    if (type == MIRType::Int32) {
+      bailoutCmp32(cond, lhs, Imm32(rhs), snapshot);
+    } else {
+      MOZ_ASSERT(type == MIRType::IntPtr);
+      bailoutCmpPtr(cond, lhs, ImmWord(rhs), snapshot);
+    }
+  };
+
+  if (lir->index()->isConstant()) {
+    int32_t nmin, nmax;
+    int32_t index = ToInt32(lir->index());
+    if (SafeAdd(index, min, &nmin) && SafeAdd(index, max, &nmax) && nmin >= 0) {
+      if (length->isRegister()) {
+        bailoutCmpConstant(Assembler::BelowOrEqual, ToRegister(length), nmax);
+      } else {
+        bailoutCmpConstant(Assembler::BelowOrEqual, ToAddress(length), nmax);
+      }
+      return;
+    }
+    masm.mov(ImmWord(index), temp);
+  } else {
+    masm.mov(ToRegister(lir->index()), temp);
+  }
+
+  // If the minimum and maximum differ then do an underflow check first.
+  // If the two are the same then doing an unsigned comparison on the
+  // length will also catch a negative index.
+  if (min != max) {
+    if (min != 0) {
+      Label bail;
+      if (type == MIRType::Int32) {
+        masm.branchAdd32(Assembler::Overflow, Imm32(min), temp, &bail);
+      } else {
+        masm.branchAddPtr(Assembler::Overflow, Imm32(min), temp, &bail);
+      }
+      bailoutFrom(&bail, snapshot);
+    }
+
+    bailoutCmpConstant(Assembler::LessThan, temp, 0);
+
+    if (min != 0) {
+      int32_t diff;
+      if (SafeSub(max, min, &diff)) {
+        max = diff;
+      } else {
+        if (type == MIRType::Int32) {
+          masm.sub32(Imm32(min), temp);
+        } else {
+          masm.subPtr(Imm32(min), temp);
+        }
+      }
+    }
+  }
+
+  // Compute the maximum possible index. No overflow check is needed when
+  // max > 0. We can only wraparound to a negative number, which will test as
+  // larger than all nonnegative numbers in the unsigned comparison, and the
+  // length is required to be nonnegative (else testing a negative length
+  // would succeed on any nonnegative index).
+  if (max != 0) {
+    if (max < 0) {
+      Label bail;
+      if (type == MIRType::Int32) {
+        masm.branchAdd32(Assembler::Overflow, Imm32(max), temp, &bail);
+      } else {
+        masm.branchAddPtr(Assembler::Overflow, Imm32(max), temp, &bail);
+      }
+      bailoutFrom(&bail, snapshot);
+    } else {
+      if (type == MIRType::Int32) {
+        masm.add32(Imm32(max), temp);
+      } else {
+        masm.addPtr(Imm32(max), temp);
+      }
+    }
+  }
+
+  if (length->isRegister()) {
+    bailoutCmp(Assembler::BelowOrEqual, ToRegister(length), temp);
+  } else {
+    bailoutCmp(Assembler::BelowOrEqual, ToAddress(length), temp);
+  }
+}
+
+void CodeGenerator::visitBoundsCheckLower(LBoundsCheckLower* lir) {
+  int32_t min = lir->mir()->minimum();
+  bailoutCmp32(Assembler::LessThan, ToRegister(lir->index()), Imm32(min),
+               lir->snapshot());
+}
+
+void CodeGenerator::visitSpectreMaskIndex(LSpectreMaskIndex* lir) {
+  MOZ_ASSERT(JitOptions.spectreIndexMasking);
+
+  const LAllocation* length = lir->length();
+  Register index = ToRegister(lir->index());
+  Register output = ToRegister(lir->output());
+
+  if (lir->mir()->type() == MIRType::Int32) {
+    if (length->isRegister()) {
+      masm.spectreMaskIndex32(index, ToRegister(length), output);
+    } else {
+      masm.spectreMaskIndex32(index, ToAddress(length), output);
+    }
+  } else {
+    MOZ_ASSERT(lir->mir()->type() == MIRType::IntPtr);
+    if (length->isRegister()) {
+      masm.spectreMaskIndexPtr(index, ToRegister(length), output);
+    } else {
+      masm.spectreMaskIndexPtr(index, ToAddress(length), output);
+    }
+  }
+}
+
+class OutOfLineStoreElementHole : public OutOfLineCodeBase<CodeGenerator> {
+  LInstruction* ins_;
+
+ public:
+  explicit OutOfLineStoreElementHole(LInstruction* ins) : ins_(ins) {
+    MOZ_ASSERT(ins->isStoreElementHoleV() || ins->isStoreElementHoleT());
+  }
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineStoreElementHole(this);
+  }
+
+  MStoreElementHole* mir() const {
+    return ins_->isStoreElementHoleV() ? ins_->toStoreElementHoleV()->mir()
+                                       : ins_->toStoreElementHoleT()->mir();
+  }
+  LInstruction* ins() const { return ins_; }
+};
+
+void CodeGenerator::emitStoreHoleCheck(Register elements,
+                                       const LAllocation* index,
+                                       LSnapshot* snapshot) {
+  Label bail;
+  if (index->isConstant()) {
+    Address dest(elements, ToInt32(index) * sizeof(js::Value));
+    masm.branchTestMagic(Assembler::Equal, dest, &bail);
+  } else {
+    BaseObjectElementIndex dest(elements, ToRegister(index));
+    masm.branchTestMagic(Assembler::Equal, dest, &bail);
+  }
+  bailoutFrom(&bail, snapshot);
+}
+
+void CodeGenerator::emitStoreElementTyped(const LAllocation* value,
+                                          MIRType valueType, Register elements,
+                                          const LAllocation* index) {
+  MOZ_ASSERT(valueType != MIRType::MagicHole);
+  ConstantOrRegister v = ToConstantOrRegister(value, valueType);
+  if (index->isConstant()) {
+    Address dest(elements, ToInt32(index) * sizeof(js::Value));
+    masm.storeUnboxedValue(v, valueType, dest);
+  } else {
+    BaseObjectElementIndex dest(elements, ToRegister(index));
+    masm.storeUnboxedValue(v, valueType, dest);
+  }
+}
+
+void CodeGenerator::visitStoreElementT(LStoreElementT* store) {
+  Register elements = ToRegister(store->elements());
+  const LAllocation* index = store->index();
+
+  if (store->mir()->needsBarrier()) {
+    emitPreBarrier(elements, index);
+  }
+
+  if (store->mir()->needsHoleCheck()) {
+    emitStoreHoleCheck(elements, index, store->snapshot());
+  }
+
+  emitStoreElementTyped(store->value(), store->mir()->value()->type(), elements,
+                        index);
+}
+
+void CodeGenerator::visitStoreElementV(LStoreElementV* lir) {
+  const ValueOperand value = ToValue(lir, LStoreElementV::Value);
+  Register elements = ToRegister(lir->elements());
+  const LAllocation* index = lir->index();
+
+  if (lir->mir()->needsBarrier()) {
+    emitPreBarrier(elements, index);
+  }
+
+  if (lir->mir()->needsHoleCheck()) {
+    emitStoreHoleCheck(elements, index, lir->snapshot());
+  }
+
+  if (lir->index()->isConstant()) {
+    Address dest(elements, ToInt32(lir->index()) * sizeof(js::Value));
+    masm.storeValue(value, dest);
+  } else {
+    BaseObjectElementIndex dest(elements, ToRegister(lir->index()));
+    masm.storeValue(value, dest);
+  }
+}
+
+void CodeGenerator::visitStoreHoleValueElement(LStoreHoleValueElement* lir) {
+  Register elements = ToRegister(lir->elements());
+  Register index = ToRegister(lir->index());
+
+  Address elementsFlags(elements, ObjectElements::offsetOfFlags());
+  masm.or32(Imm32(ObjectElements::NON_PACKED), elementsFlags);
+
+  BaseObjectElementIndex element(elements, index);
+  masm.storeValue(MagicValue(JS_ELEMENTS_HOLE), element);
+}
+
+void CodeGenerator::visitStoreElementHoleT(LStoreElementHoleT* lir) {
+  auto* ool = new (alloc()) OutOfLineStoreElementHole(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  Register obj = ToRegister(lir->object());
+  Register elements = ToRegister(lir->elements());
+  Register index = ToRegister(lir->index());
+  Register temp = ToRegister(lir->temp0());
+
+  Address initLength(elements, ObjectElements::offsetOfInitializedLength());
+  masm.spectreBoundsCheck32(index, initLength, temp, ool->entry());
+
+  emitPreBarrier(elements, lir->index());
+
+  masm.bind(ool->rejoin());
+  emitStoreElementTyped(lir->value(), lir->mir()->value()->type(), elements,
+                        lir->index());
+
+  if (ValueNeedsPostBarrier(lir->mir()->value())) {
+    LiveRegisterSet regs = liveVolatileRegs(lir);
+    ConstantOrRegister val =
+        ToConstantOrRegister(lir->value(), lir->mir()->value()->type());
+    emitElementPostWriteBarrier(lir->mir(), regs, obj, lir->index(), temp, val);
+  }
+}
+
+void CodeGenerator::visitStoreElementHoleV(LStoreElementHoleV* lir) {
+  auto* ool = new (alloc()) OutOfLineStoreElementHole(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  Register obj = ToRegister(lir->object());
+  Register elements = ToRegister(lir->elements());
+  Register index = ToRegister(lir->index());
+  const ValueOperand value = ToValue(lir, LStoreElementHoleV::ValueIndex);
+  Register temp = ToRegister(lir->temp0());
+
+  Address initLength(elements, ObjectElements::offsetOfInitializedLength());
+  masm.spectreBoundsCheck32(index, initLength, temp, ool->entry());
+
+  emitPreBarrier(elements, lir->index());
+
+  masm.bind(ool->rejoin());
+  masm.storeValue(value, BaseObjectElementIndex(elements, index));
+
+  if (ValueNeedsPostBarrier(lir->mir()->value())) {
+    LiveRegisterSet regs = liveVolatileRegs(lir);
+    emitElementPostWriteBarrier(lir->mir(), regs, obj, lir->index(), temp,
+                                ConstantOrRegister(value));
+  }
+}
+
+void CodeGenerator::visitOutOfLineStoreElementHole(
+    OutOfLineStoreElementHole* ool) {
+  Register object, elements, index;
+  LInstruction* ins = ool->ins();
+  mozilla::Maybe<ConstantOrRegister> value;
+  Register temp;
+
+  if (ins->isStoreElementHoleV()) {
+    LStoreElementHoleV* store = ins->toStoreElementHoleV();
+    object = ToRegister(store->object());
+    elements = ToRegister(store->elements());
+    index = ToRegister(store->index());
+    value.emplace(
+        TypedOrValueRegister(ToValue(store, LStoreElementHoleV::ValueIndex)));
+    temp = ToRegister(store->temp0());
+  } else {
+    LStoreElementHoleT* store = ins->toStoreElementHoleT();
+    object = ToRegister(store->object());
+    elements = ToRegister(store->elements());
+    index = ToRegister(store->index());
+    if (store->value()->isConstant()) {
+      value.emplace(
+          ConstantOrRegister(store->value()->toConstant()->toJSValue()));
+    } else {
+      MIRType valueType = store->mir()->value()->type();
+      value.emplace(
+          TypedOrValueRegister(valueType, ToAnyRegister(store->value())));
+    }
+    temp = ToRegister(store->temp0());
+  }
+
+  Address initLength(elements, ObjectElements::offsetOfInitializedLength());
+
+  // We're out-of-bounds. We only handle the index == initlength case.
+  // If index > initializedLength, bail out. Note that this relies on the
+  // condition flags sticking from the incoming branch.
+  // Also note: this branch does not need Spectre mitigations, doing that for
+  // the capacity check below is sufficient.
+  Label allocElement, addNewElement;
+#if defined(JS_CODEGEN_MIPS32) || defined(JS_CODEGEN_MIPS64) || \
+    defined(JS_CODEGEN_LOONG64) || defined(JS_CODEGEN_RISCV64)
+  // Had to reimplement for MIPS because there are no flags.
+  bailoutCmp32(Assembler::NotEqual, initLength, index, ins->snapshot());
+#else
+  bailoutIf(Assembler::NotEqual, ins->snapshot());
+#endif
+
+  // If index < capacity, we can add a dense element inline. If not, we need
+  // to allocate more elements first.
+  masm.spectreBoundsCheck32(
+      index, Address(elements, ObjectElements::offsetOfCapacity()), temp,
+      &allocElement);
+  masm.jump(&addNewElement);
+
+  masm.bind(&allocElement);
+
+  // Save all live volatile registers, except |temp|.
+  LiveRegisterSet liveRegs = liveVolatileRegs(ins);
+  liveRegs.takeUnchecked(temp);
+  masm.PushRegsInMask(liveRegs);
+
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp);
+  masm.passABIArg(temp);
+  masm.passABIArg(object);
+
+  using Fn = bool (*)(JSContext*, NativeObject*);
+  masm.callWithABI<Fn, NativeObject::addDenseElementPure>();
+  masm.storeCallPointerResult(temp);
+
+  masm.PopRegsInMask(liveRegs);
+  bailoutIfFalseBool(temp, ins->snapshot());
+
+  // Load the reallocated elements pointer.
+  masm.loadPtr(Address(object, NativeObject::offsetOfElements()), elements);
+
+  masm.bind(&addNewElement);
+
+  // Increment initLength
+  masm.add32(Imm32(1), initLength);
+
+  // If length is now <= index, increment length too.
+  Label skipIncrementLength;
+  Address length(elements, ObjectElements::offsetOfLength());
+  masm.branch32(Assembler::Above, length, index, &skipIncrementLength);
+  masm.add32(Imm32(1), length);
+  masm.bind(&skipIncrementLength);
+
+  // Jump to the inline path where we will store the value.
+  // We rejoin after the prebarrier, because the memory is uninitialized.
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitArrayPopShift(LArrayPopShift* lir) {
+  Register obj = ToRegister(lir->object());
+  Register temp1 = ToRegister(lir->temp0());
+  Register temp2 = ToRegister(lir->temp1());
+  ValueOperand out = ToOutValue(lir);
+
+  Label bail;
+  if (lir->mir()->mode() == MArrayPopShift::Pop) {
+    masm.packedArrayPop(obj, out, temp1, temp2, &bail);
+  } else {
+    MOZ_ASSERT(lir->mir()->mode() == MArrayPopShift::Shift);
+    LiveRegisterSet volatileRegs = liveVolatileRegs(lir);
+    masm.packedArrayShift(obj, out, temp1, temp2, volatileRegs, &bail);
+  }
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+class OutOfLineArrayPush : public OutOfLineCodeBase<CodeGenerator> {
+  LArrayPush* ins_;
+
+ public:
+  explicit OutOfLineArrayPush(LArrayPush* ins) : ins_(ins) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineArrayPush(this);
+  }
+
+  LArrayPush* ins() const { return ins_; }
+};
+
+void CodeGenerator::visitArrayPush(LArrayPush* lir) {
+  Register obj = ToRegister(lir->object());
+  Register elementsTemp = ToRegister(lir->temp0());
+  Register length = ToRegister(lir->output());
+  ValueOperand value = ToValue(lir, LArrayPush::ValueIndex);
+  Register spectreTemp = ToTempRegisterOrInvalid(lir->temp1());
+
+  auto* ool = new (alloc()) OutOfLineArrayPush(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  // Load elements and length.
+  masm.loadPtr(Address(obj, NativeObject::offsetOfElements()), elementsTemp);
+  masm.load32(Address(elementsTemp, ObjectElements::offsetOfLength()), length);
+
+  // TODO(post-Warp): reuse/share the CacheIR implementation when IonBuilder and
+  // TI are gone (bug 1654180).
+
+  // Bailout if the incremented length does not fit in int32.
+  bailoutCmp32(Assembler::AboveOrEqual, length, Imm32(INT32_MAX),
+               lir->snapshot());
+
+  // Guard length == initializedLength.
+  Address initLength(elementsTemp, ObjectElements::offsetOfInitializedLength());
+  masm.branch32(Assembler::NotEqual, initLength, length, ool->entry());
+
+  // Guard length < capacity.
+  Address capacity(elementsTemp, ObjectElements::offsetOfCapacity());
+  masm.spectreBoundsCheck32(length, capacity, spectreTemp, ool->entry());
+
+  // Do the store.
+  masm.storeValue(value, BaseObjectElementIndex(elementsTemp, length));
+
+  masm.add32(Imm32(1), length);
+
+  // Update length and initialized length.
+  masm.store32(length, Address(elementsTemp, ObjectElements::offsetOfLength()));
+  masm.store32(length, Address(elementsTemp,
+                               ObjectElements::offsetOfInitializedLength()));
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineArrayPush(OutOfLineArrayPush* ool) {
+  LArrayPush* ins = ool->ins();
+
+  Register object = ToRegister(ins->object());
+  Register temp = ToRegister(ins->temp0());
+  Register output = ToRegister(ins->output());
+  ValueOperand value = ToValue(ins, LArrayPush::ValueIndex);
+
+  // Save all live volatile registers, except |temp| and |output|, because both
+  // are overwritten anyway.
+  LiveRegisterSet liveRegs = liveVolatileRegs(ins);
+  liveRegs.takeUnchecked(temp);
+  liveRegs.takeUnchecked(output);
+
+  masm.PushRegsInMask(liveRegs);
+
+  masm.Push(value);
+  masm.moveStackPtrTo(output);
+
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp);
+  masm.passABIArg(temp);
+  masm.passABIArg(object);
+  masm.passABIArg(output);
+
+  using Fn = bool (*)(JSContext*, ArrayObject*, Value*);
+  masm.callWithABI<Fn, jit::ArrayPushDensePure>();
+  masm.storeCallPointerResult(temp);
+
+  masm.freeStack(sizeof(Value));  // Discard pushed Value.
+
+  MOZ_ASSERT(!liveRegs.has(temp));
+  masm.PopRegsInMask(liveRegs);
+
+  bailoutIfFalseBool(temp, ins->snapshot());
+
+  // Load the new length into the output register.
+  masm.loadPtr(Address(object, NativeObject::offsetOfElements()), output);
+  masm.load32(Address(output, ObjectElements::offsetOfLength()), output);
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitArraySlice(LArraySlice* lir) {
+  Register object = ToRegister(lir->object());
+  Register begin = ToRegister(lir->begin());
+  Register end = ToRegister(lir->end());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  Label call, fail;
+
+  Label bail;
+  masm.branchArrayIsNotPacked(object, temp0, temp1, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+
+  // Try to allocate an object.
+  TemplateObject templateObject(lir->mir()->templateObj());
+  masm.createGCObject(temp0, temp1, templateObject, lir->mir()->initialHeap(),
+                      &fail);
+
+  masm.jump(&call);
+  {
+    masm.bind(&fail);
+    masm.movePtr(ImmPtr(nullptr), temp0);
+  }
+  masm.bind(&call);
+
+  pushArg(temp0);
+  pushArg(end);
+  pushArg(begin);
+  pushArg(object);
+
+  using Fn =
+      JSObject* (*)(JSContext*, HandleObject, int32_t, int32_t, HandleObject);
+  callVM<Fn, ArraySliceDense>(lir);
+}
+
+void CodeGenerator::visitArgumentsSlice(LArgumentsSlice* lir) {
+  Register object = ToRegister(lir->object());
+  Register begin = ToRegister(lir->begin());
+  Register end = ToRegister(lir->end());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  Label call, fail;
+
+  // Try to allocate an object.
+  TemplateObject templateObject(lir->mir()->templateObj());
+  masm.createGCObject(temp0, temp1, templateObject, lir->mir()->initialHeap(),
+                      &fail);
+
+  masm.jump(&call);
+  {
+    masm.bind(&fail);
+    masm.movePtr(ImmPtr(nullptr), temp0);
+  }
+  masm.bind(&call);
+
+  pushArg(temp0);
+  pushArg(end);
+  pushArg(begin);
+  pushArg(object);
+
+  using Fn =
+      JSObject* (*)(JSContext*, HandleObject, int32_t, int32_t, HandleObject);
+  callVM<Fn, ArgumentsSliceDense>(lir);
+}
+
+#ifdef DEBUG
+void CodeGenerator::emitAssertArgumentsSliceBounds(const RegisterOrInt32& begin,
+                                                   const RegisterOrInt32& count,
+                                                   Register numActualArgs) {
+  // |begin| must be positive or zero.
+  if (begin.is<Register>()) {
+    Label beginOk;
+    masm.branch32(Assembler::GreaterThanOrEqual, begin.as<Register>(), Imm32(0),
+                  &beginOk);
+    masm.assumeUnreachable("begin < 0");
+    masm.bind(&beginOk);
+  } else {
+    MOZ_ASSERT(begin.as<int32_t>() >= 0);
+  }
+
+  // |count| must be positive or zero.
+  if (count.is<Register>()) {
+    Label countOk;
+    masm.branch32(Assembler::GreaterThanOrEqual, count.as<Register>(), Imm32(0),
+                  &countOk);
+    masm.assumeUnreachable("count < 0");
+    masm.bind(&countOk);
+  } else {
+    MOZ_ASSERT(count.as<int32_t>() >= 0);
+  }
+
+  // |begin| must be less-or-equal to |numActualArgs|.
+  Label argsBeginOk;
+  if (begin.is<Register>()) {
+    masm.branchPtr(Assembler::AboveOrEqual, numActualArgs, begin.as<Register>(),
+                   &argsBeginOk);
+  } else {
+    masm.branchPtr(Assembler::AboveOrEqual, numActualArgs,
+                   Imm32(begin.as<int32_t>()), &argsBeginOk);
+  }
+  masm.assumeUnreachable("begin <= numActualArgs");
+  masm.bind(&argsBeginOk);
+
+  // |count| must be less-or-equal to |numActualArgs|.
+  Label argsCountOk;
+  if (count.is<Register>()) {
+    masm.branchPtr(Assembler::AboveOrEqual, numActualArgs, count.as<Register>(),
+                   &argsCountOk);
+  } else {
+    masm.branchPtr(Assembler::AboveOrEqual, numActualArgs,
+                   Imm32(count.as<int32_t>()), &argsCountOk);
+  }
+  masm.assumeUnreachable("count <= numActualArgs");
+  masm.bind(&argsCountOk);
+
+  // |begin| and |count| must be preserved, but |numActualArgs| can be changed.
+  //
+  // Pre-condition: |count| <= |numActualArgs|
+  // Condition to test: |begin + count| <= |numActualArgs|
+  // Transform to: |begin| <= |numActualArgs - count|
+  if (count.is<Register>()) {
+    masm.subPtr(count.as<Register>(), numActualArgs);
+  } else {
+    masm.subPtr(Imm32(count.as<int32_t>()), numActualArgs);
+  }
+
+  // |begin + count| must be less-or-equal to |numActualArgs|.
+  Label argsBeginCountOk;
+  if (begin.is<Register>()) {
+    masm.branchPtr(Assembler::AboveOrEqual, numActualArgs, begin.as<Register>(),
+                   &argsBeginCountOk);
+  } else {
+    masm.branchPtr(Assembler::AboveOrEqual, numActualArgs,
+                   Imm32(begin.as<int32_t>()), &argsBeginCountOk);
+  }
+  masm.assumeUnreachable("begin + count <= numActualArgs");
+  masm.bind(&argsBeginCountOk);
+}
+#endif
+
+template <class ArgumentsSlice>
+void CodeGenerator::emitNewArray(ArgumentsSlice* lir,
+                                 const RegisterOrInt32& count, Register output,
+                                 Register temp) {
+  using Fn = ArrayObject* (*)(JSContext*, int32_t);
+  auto* ool = count.match(
+      [&](Register count) {
+        return oolCallVM<Fn, NewArrayObjectEnsureDenseInitLength>(
+            lir, ArgList(count), StoreRegisterTo(output));
+      },
+      [&](int32_t count) {
+        return oolCallVM<Fn, NewArrayObjectEnsureDenseInitLength>(
+            lir, ArgList(Imm32(count)), StoreRegisterTo(output));
+      });
+
+  TemplateObject templateObject(lir->mir()->templateObj());
+  MOZ_ASSERT(templateObject.isArrayObject());
+
+  auto templateNativeObj = templateObject.asTemplateNativeObject();
+  MOZ_ASSERT(templateNativeObj.getArrayLength() == 0);
+  MOZ_ASSERT(templateNativeObj.getDenseInitializedLength() == 0);
+  MOZ_ASSERT(!templateNativeObj.hasDynamicElements());
+
+  // Check array capacity. Call into the VM if the template object's capacity
+  // is too small.
+  bool tryAllocate = count.match(
+      [&](Register count) {
+        masm.branch32(Assembler::Above, count,
+                      Imm32(templateNativeObj.getDenseCapacity()),
+                      ool->entry());
+        return true;
+      },
+      [&](int32_t count) {
+        MOZ_ASSERT(count >= 0);
+        if (uint32_t(count) > templateNativeObj.getDenseCapacity()) {
+          masm.jump(ool->entry());
+          return false;
+        }
+        return true;
+      });
+
+  if (tryAllocate) {
+    // Try to allocate an object.
+    masm.createGCObject(output, temp, templateObject, lir->mir()->initialHeap(),
+                        ool->entry());
+
+    auto setInitializedLengthAndLength = [&](auto count) {
+      const int elementsOffset = NativeObject::offsetOfFixedElements();
+
+      // Update initialized length.
+      Address initLength(
+          output, elementsOffset + ObjectElements::offsetOfInitializedLength());
+      masm.store32(count, initLength);
+
+      // Update length.
+      Address length(output, elementsOffset + ObjectElements::offsetOfLength());
+      masm.store32(count, length);
+    };
+
+    // The array object was successfully created. Set the length and initialized
+    // length and then proceed to fill the elements.
+    count.match([&](Register count) { setInitializedLengthAndLength(count); },
+                [&](int32_t count) {
+                  if (count > 0) {
+                    setInitializedLengthAndLength(Imm32(count));
+                  }
+                });
+  }
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitFrameArgumentsSlice(LFrameArgumentsSlice* lir) {
+  Register begin = ToRegister(lir->begin());
+  Register count = ToRegister(lir->count());
+  Register temp = ToRegister(lir->temp0());
+  Register output = ToRegister(lir->output());
+
+#ifdef DEBUG
+  masm.loadNumActualArgs(FramePointer, temp);
+  emitAssertArgumentsSliceBounds(RegisterOrInt32(begin), RegisterOrInt32(count),
+                                 temp);
+#endif
+
+  emitNewArray(lir, RegisterOrInt32(count), output, temp);
+
+  Label done;
+  masm.branch32(Assembler::Equal, count, Imm32(0), &done);
+  {
+    AllocatableGeneralRegisterSet allRegs(GeneralRegisterSet::All());
+    allRegs.take(begin);
+    allRegs.take(count);
+    allRegs.take(temp);
+    allRegs.take(output);
+
+    ValueOperand value = allRegs.takeAnyValue();
+
+    LiveRegisterSet liveRegs;
+    liveRegs.add(output);
+    liveRegs.add(begin);
+    liveRegs.add(value);
+
+    masm.PushRegsInMask(liveRegs);
+
+    // Initialize all elements.
+
+    Register elements = output;
+    masm.loadPtr(Address(output, NativeObject::offsetOfElements()), elements);
+
+    Register argIndex = begin;
+
+    Register index = temp;
+    masm.move32(Imm32(0), index);
+
+    size_t argvOffset = JitFrameLayout::offsetOfActualArgs();
+    BaseValueIndex argPtr(FramePointer, argIndex, argvOffset);
+
+    Label loop;
+    masm.bind(&loop);
+
+    masm.loadValue(argPtr, value);
+
+    // We don't need a pre-barrier, because the element at |index| is guaranteed
+    // to be a non-GC thing (either uninitialized memory or the magic hole
+    // value).
+    masm.storeValue(value, BaseObjectElementIndex(elements, index));
+
+    masm.add32(Imm32(1), index);
+    masm.add32(Imm32(1), argIndex);
+
+    masm.branch32(Assembler::LessThan, index, count, &loop);
+
+    masm.PopRegsInMask(liveRegs);
+
+    // Emit a post-write barrier if |output| is tenured.
+    //
+    // We expect that |output| is nursery allocated, so it isn't worth the
+    // trouble to check if no frame argument is a nursery thing, which would
+    // allow to omit the post-write barrier.
+    masm.branchPtrInNurseryChunk(Assembler::Equal, output, temp, &done);
+
+    LiveRegisterSet volatileRegs = liveVolatileRegs(lir);
+    volatileRegs.takeUnchecked(temp);
+    if (output.volatile_()) {
+      volatileRegs.addUnchecked(output);
+    }
+
+    masm.PushRegsInMask(volatileRegs);
+    emitPostWriteBarrier(output);
+    masm.PopRegsInMask(volatileRegs);
+  }
+  masm.bind(&done);
+}
+
+CodeGenerator::RegisterOrInt32 CodeGenerator::ToRegisterOrInt32(
+    const LAllocation* allocation) {
+  if (allocation->isConstant()) {
+    return RegisterOrInt32(allocation->toConstant()->toInt32());
+  }
+  return RegisterOrInt32(ToRegister(allocation));
+}
+
+void CodeGenerator::visitInlineArgumentsSlice(LInlineArgumentsSlice* lir) {
+  RegisterOrInt32 begin = ToRegisterOrInt32(lir->begin());
+  RegisterOrInt32 count = ToRegisterOrInt32(lir->count());
+  Register temp = ToRegister(lir->temp());
+  Register output = ToRegister(lir->output());
+
+  uint32_t numActuals = lir->mir()->numActuals();
+
+#ifdef DEBUG
+  masm.move32(Imm32(numActuals), temp);
+
+  emitAssertArgumentsSliceBounds(begin, count, temp);
+#endif
+
+  emitNewArray(lir, count, output, temp);
+
+  // We're done if there are no actual arguments.
+  if (numActuals == 0) {
+    return;
+  }
+
+  // Check if any arguments have to be copied.
+  Label done;
+  if (count.is<Register>()) {
+    masm.branch32(Assembler::Equal, count.as<Register>(), Imm32(0), &done);
+  } else if (count.as<int32_t>() == 0) {
+    return;
+  }
+
+  auto getArg = [&](uint32_t i) {
+    return toConstantOrRegister(lir, LInlineArgumentsSlice::ArgIndex(i),
+                                lir->mir()->getArg(i)->type());
+  };
+
+  auto storeArg = [&](uint32_t i, auto dest) {
+    // We don't need a pre-barrier because the element at |index| is guaranteed
+    // to be a non-GC thing (either uninitialized memory or the magic hole
+    // value).
+    masm.storeConstantOrRegister(getArg(i), dest);
+  };
+
+  // Initialize all elements.
+  if (numActuals == 1) {
+    // There's exactly one argument. We've checked that |count| is non-zero,
+    // which implies that |begin| must be zero.
+    MOZ_ASSERT_IF(begin.is<int32_t>(), begin.as<int32_t>() == 0);
+
+    Register elements = temp;
+    masm.loadPtr(Address(output, NativeObject::offsetOfElements()), elements);
+
+    storeArg(0, Address(elements, 0));
+  } else if (begin.is<Register>()) {
+    // There is more than one argument and |begin| isn't a compile-time
+    // constant. Iterate through 0..numActuals to search for |begin| and then
+    // start copying |count| arguments from that index.
+
+    LiveGeneralRegisterSet liveRegs;
+    liveRegs.add(output);
+    liveRegs.add(begin.as<Register>());
+
+    masm.PushRegsInMask(liveRegs);
+
+    Register elements = output;
+    masm.loadPtr(Address(output, NativeObject::offsetOfElements()), elements);
+
+    Register argIndex = begin.as<Register>();
+
+    Register index = temp;
+    masm.move32(Imm32(0), index);
+
+    Label doneLoop;
+    for (uint32_t i = 0; i < numActuals; ++i) {
+      Label next;
+      masm.branch32(Assembler::NotEqual, argIndex, Imm32(i), &next);
+
+      storeArg(i, BaseObjectElementIndex(elements, index));
+
+      masm.add32(Imm32(1), index);
+      masm.add32(Imm32(1), argIndex);
+
+      if (count.is<Register>()) {
+        masm.branch32(Assembler::GreaterThanOrEqual, index,
+                      count.as<Register>(), &doneLoop);
+      } else {
+        masm.branch32(Assembler::GreaterThanOrEqual, index,
+                      Imm32(count.as<int32_t>()), &doneLoop);
+      }
+
+      masm.bind(&next);
+    }
+    masm.bind(&doneLoop);
+
+    masm.PopRegsInMask(liveRegs);
+  } else {
+    // There is more than one argument and |begin| is a compile-time constant.
+
+    Register elements = temp;
+    masm.loadPtr(Address(output, NativeObject::offsetOfElements()), elements);
+
+    int32_t argIndex = begin.as<int32_t>();
+
+    int32_t index = 0;
+
+    Label doneLoop;
+    for (uint32_t i = argIndex; i < numActuals; ++i) {
+      storeArg(i, Address(elements, index * sizeof(Value)));
+
+      index += 1;
+
+      if (count.is<Register>()) {
+        masm.branch32(Assembler::LessThanOrEqual, count.as<Register>(),
+                      Imm32(index), &doneLoop);
+      } else {
+        if (index >= count.as<int32_t>()) {
+          break;
+        }
+      }
+    }
+    masm.bind(&doneLoop);
+  }
+
+  // Determine if we have to emit post-write barrier.
+  //
+  // If either |begin| or |count| is a constant, use their value directly.
+  // Otherwise assume we copy all inline arguments from 0..numActuals.
+  bool postWriteBarrier = false;
+  uint32_t actualBegin = begin.match([](Register) { return 0; },
+                                     [](int32_t value) { return value; });
+  uint32_t actualCount =
+      count.match([=](Register) { return numActuals; },
+                  [](int32_t value) -> uint32_t { return value; });
+  for (uint32_t i = 0; i < actualCount; ++i) {
+    ConstantOrRegister arg = getArg(actualBegin + i);
+    if (arg.constant()) {
+      Value v = arg.value();
+      if (v.isGCThing() && IsInsideNursery(v.toGCThing())) {
+        postWriteBarrier = true;
+      }
+    } else {
+      MIRType type = arg.reg().type();
+      if (type == MIRType::Value || NeedsPostBarrier(type)) {
+        postWriteBarrier = true;
+      }
+    }
+  }
+
+  // Emit a post-write barrier if |output| is tenured and we couldn't
+  // determine at compile-time that no barrier is needed.
+  if (postWriteBarrier) {
+    masm.branchPtrInNurseryChunk(Assembler::Equal, output, temp, &done);
+
+    LiveRegisterSet volatileRegs = liveVolatileRegs(lir);
+    volatileRegs.takeUnchecked(temp);
+    if (output.volatile_()) {
+      volatileRegs.addUnchecked(output);
+    }
+
+    masm.PushRegsInMask(volatileRegs);
+    emitPostWriteBarrier(output);
+    masm.PopRegsInMask(volatileRegs);
+  }
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitNormalizeSliceTerm(LNormalizeSliceTerm* lir) {
+  Register value = ToRegister(lir->value());
+  Register length = ToRegister(lir->length());
+  Register output = ToRegister(lir->output());
+
+  masm.move32(value, output);
+
+  Label positive;
+  masm.branch32(Assembler::GreaterThanOrEqual, value, Imm32(0), &positive);
+
+  Label done;
+  masm.add32(length, output);
+  masm.branch32(Assembler::GreaterThanOrEqual, output, Imm32(0), &done);
+  masm.move32(Imm32(0), output);
+  masm.jump(&done);
+
+  masm.bind(&positive);
+  masm.cmp32Move32(Assembler::LessThan, length, value, length, output);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitArrayJoin(LArrayJoin* lir) {
+  Label skipCall;
+
+  Register output = ToRegister(lir->output());
+  Register sep = ToRegister(lir->separator());
+  Register array = ToRegister(lir->array());
+  Register temp = ToRegister(lir->temp0());
+
+  // Fast path for simple length <= 1 cases.
+  {
+    masm.loadPtr(Address(array, NativeObject::offsetOfElements()), temp);
+    Address length(temp, ObjectElements::offsetOfLength());
+    Address initLength(temp, ObjectElements::offsetOfInitializedLength());
+
+    // Check for length == 0
+    Label notEmpty;
+    masm.branch32(Assembler::NotEqual, length, Imm32(0), &notEmpty);
+    const JSAtomState& names = gen->runtime->names();
+    masm.movePtr(ImmGCPtr(names.empty), output);
+    masm.jump(&skipCall);
+
+    masm.bind(&notEmpty);
+    Label notSingleString;
+    // Check for length == 1, initializedLength >= 1, arr[0].isString()
+    masm.branch32(Assembler::NotEqual, length, Imm32(1), &notSingleString);
+    masm.branch32(Assembler::LessThan, initLength, Imm32(1), &notSingleString);
+
+    Address elem0(temp, 0);
+    masm.branchTestString(Assembler::NotEqual, elem0, &notSingleString);
+
+    // At this point, 'output' can be used as a scratch register, since we're
+    // guaranteed to succeed.
+    masm.unboxString(elem0, output);
+    masm.jump(&skipCall);
+    masm.bind(&notSingleString);
+  }
+
+  pushArg(sep);
+  pushArg(array);
+
+  using Fn = JSString* (*)(JSContext*, HandleObject, HandleString);
+  callVM<Fn, jit::ArrayJoin>(lir);
+  masm.bind(&skipCall);
+}
+
+void CodeGenerator::visitGetIteratorCache(LGetIteratorCache* lir) {
+  LiveRegisterSet liveRegs = lir->safepoint()->liveRegs();
+  TypedOrValueRegister val =
+      toConstantOrRegister(lir, LGetIteratorCache::ValueIndex,
+                           lir->mir()->value()->type())
+          .reg();
+  Register output = ToRegister(lir->output());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  IonGetIteratorIC ic(liveRegs, val, output, temp0, temp1);
+  addIC(lir, allocateIC(ic));
+}
+
+void CodeGenerator::visitOptimizeSpreadCallCache(
+    LOptimizeSpreadCallCache* lir) {
+  LiveRegisterSet liveRegs = lir->safepoint()->liveRegs();
+  ValueOperand val = ToValue(lir, LOptimizeSpreadCallCache::ValueIndex);
+  ValueOperand output = ToOutValue(lir);
+  Register temp = ToRegister(lir->temp0());
+
+  IonOptimizeSpreadCallIC ic(liveRegs, val, output, temp);
+  addIC(lir, allocateIC(ic));
+}
+
+void CodeGenerator::visitCloseIterCache(LCloseIterCache* lir) {
+  LiveRegisterSet liveRegs = lir->safepoint()->liveRegs();
+  Register iter = ToRegister(lir->iter());
+  Register temp = ToRegister(lir->temp0());
+  CompletionKind kind = CompletionKind(lir->mir()->completionKind());
+
+  IonCloseIterIC ic(liveRegs, iter, temp, kind);
+  addIC(lir, allocateIC(ic));
+}
+
+void CodeGenerator::visitIteratorMore(LIteratorMore* lir) {
+  const Register obj = ToRegister(lir->iterator());
+  const ValueOperand output = ToOutValue(lir);
+  const Register temp = ToRegister(lir->temp0());
+
+  masm.iteratorMore(obj, output, temp);
+}
+
+void CodeGenerator::visitIsNoIterAndBranch(LIsNoIterAndBranch* lir) {
+  ValueOperand input = ToValue(lir, LIsNoIterAndBranch::Input);
+  Label* ifTrue = getJumpLabelForBranch(lir->ifTrue());
+  Label* ifFalse = getJumpLabelForBranch(lir->ifFalse());
+
+  masm.branchTestMagic(Assembler::Equal, input, ifTrue);
+
+  if (!isNextBlock(lir->ifFalse()->lir())) {
+    masm.jump(ifFalse);
+  }
+}
+
+void CodeGenerator::visitIteratorEnd(LIteratorEnd* lir) {
+  const Register obj = ToRegister(lir->object());
+  const Register temp0 = ToRegister(lir->temp0());
+  const Register temp1 = ToRegister(lir->temp1());
+  const Register temp2 = ToRegister(lir->temp2());
+
+  masm.iteratorClose(obj, temp0, temp1, temp2);
+}
+
+void CodeGenerator::visitArgumentsLength(LArgumentsLength* lir) {
+  // read number of actual arguments from the JS frame.
+  Register argc = ToRegister(lir->output());
+  masm.loadNumActualArgs(FramePointer, argc);
+}
+
+void CodeGenerator::visitGetFrameArgument(LGetFrameArgument* lir) {
+  ValueOperand result = ToOutValue(lir);
+  const LAllocation* index = lir->index();
+  size_t argvOffset = JitFrameLayout::offsetOfActualArgs();
+
+  // This instruction is used to access actual arguments and formal arguments.
+  // The number of Values on the stack is |max(numFormals, numActuals)|, so we
+  // assert |index < numFormals || index < numActuals| in debug builds.
+  DebugOnly<size_t> numFormals = gen->outerInfo().script()->function()->nargs();
+
+  if (index->isConstant()) {
+    int32_t i = index->toConstant()->toInt32();
+#ifdef DEBUG
+    if (uint32_t(i) >= numFormals) {
+      Label ok;
+      Register argc = result.scratchReg();
+      masm.loadNumActualArgs(FramePointer, argc);
+      masm.branch32(Assembler::Above, argc, Imm32(i), &ok);
+      masm.assumeUnreachable("Invalid argument index");
+      masm.bind(&ok);
+    }
+#endif
+    Address argPtr(FramePointer, sizeof(Value) * i + argvOffset);
+    masm.loadValue(argPtr, result);
+  } else {
+    Register i = ToRegister(index);
+#ifdef DEBUG
+    Label ok;
+    Register argc = result.scratchReg();
+    masm.branch32(Assembler::Below, i, Imm32(numFormals), &ok);
+    masm.loadNumActualArgs(FramePointer, argc);
+    masm.branch32(Assembler::Above, argc, i, &ok);
+    masm.assumeUnreachable("Invalid argument index");
+    masm.bind(&ok);
+#endif
+    BaseValueIndex argPtr(FramePointer, i, argvOffset);
+    masm.loadValue(argPtr, result);
+  }
+}
+
+void CodeGenerator::visitGetFrameArgumentHole(LGetFrameArgumentHole* lir) {
+  ValueOperand result = ToOutValue(lir);
+  Register index = ToRegister(lir->index());
+  Register length = ToRegister(lir->length());
+  Register spectreTemp = ToTempRegisterOrInvalid(lir->temp0());
+  size_t argvOffset = JitFrameLayout::offsetOfActualArgs();
+
+  Label outOfBounds, done;
+  masm.spectreBoundsCheck32(index, length, spectreTemp, &outOfBounds);
+
+  BaseValueIndex argPtr(FramePointer, index, argvOffset);
+  masm.loadValue(argPtr, result);
+  masm.jump(&done);
+
+  masm.bind(&outOfBounds);
+  bailoutCmp32(Assembler::LessThan, index, Imm32(0), lir->snapshot());
+  masm.moveValue(UndefinedValue(), result);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitRest(LRest* lir) {
+  Register numActuals = ToRegister(lir->numActuals());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+  unsigned numFormals = lir->mir()->numFormals();
+
+  if (Shape* shape = lir->mir()->shape()) {
+    uint32_t arrayLength = 0;
+    uint32_t arrayCapacity = 2;
+    gc::AllocKind allocKind = GuessArrayGCKind(arrayCapacity);
+    MOZ_ASSERT(CanChangeToBackgroundAllocKind(allocKind, &ArrayObject::class_));
+    allocKind = ForegroundToBackgroundAllocKind(allocKind);
+    MOZ_ASSERT(GetGCKindSlots(allocKind) ==
+               arrayCapacity + ObjectElements::VALUES_PER_HEADER);
+
+    Label joinAlloc, failAlloc;
+    masm.movePtr(ImmGCPtr(shape), temp0);
+    masm.createArrayWithFixedElements(temp2, temp0, temp1, arrayLength,
+                                      arrayCapacity, allocKind,
+                                      gc::Heap::Default, &failAlloc);
+    masm.jump(&joinAlloc);
+    {
+      masm.bind(&failAlloc);
+      masm.movePtr(ImmPtr(nullptr), temp2);
+    }
+    masm.bind(&joinAlloc);
+  } else {
+    masm.movePtr(ImmPtr(nullptr), temp2);
+  }
+
+  // Set temp1 to the address of the first actual argument.
+  size_t actualsOffset = JitFrameLayout::offsetOfActualArgs();
+  masm.computeEffectiveAddress(Address(FramePointer, actualsOffset), temp1);
+
+  // Compute array length: max(numActuals - numFormals, 0).
+  Register lengthReg;
+  if (numFormals) {
+    lengthReg = temp0;
+    Label emptyLength, joinLength;
+    masm.branch32(Assembler::LessThanOrEqual, numActuals, Imm32(numFormals),
+                  &emptyLength);
+    {
+      masm.move32(numActuals, lengthReg);
+      masm.sub32(Imm32(numFormals), lengthReg);
+
+      // Skip formal arguments.
+      masm.addPtr(Imm32(sizeof(Value) * numFormals), temp1);
+
+      masm.jump(&joinLength);
+    }
+    masm.bind(&emptyLength);
+    {
+      masm.move32(Imm32(0), lengthReg);
+
+      // Leave temp1 pointed to the start of actuals() when the rest-array
+      // length is zero. We don't use |actuals() + numFormals| because
+      // |numFormals| can be any non-negative int32 value when this MRest was
+      // created from scalar replacement optimizations. And it seems
+      // questionable to compute a Value* pointer which points to who knows
+      // where.
+    }
+    masm.bind(&joinLength);
+  } else {
+    // Use numActuals directly when there are no formals.
+    lengthReg = numActuals;
+  }
+
+  pushArg(temp2);
+  pushArg(temp1);
+  pushArg(lengthReg);
+
+  using Fn = JSObject* (*)(JSContext*, uint32_t, Value*, HandleObject);
+  callVM<Fn, InitRestParameter>(lir);
+}
+
+// Create a stackmap from the given safepoint, with the structure:
+//
+//   <reg dump area, if trap>
+//   |       ++ <body (general spill)>
+//   |               ++ <space for Frame>
+//   |                       ++ <inbound args>
+//   |                                       |
+//   Lowest Addr                             Highest Addr
+//
+// The caller owns the resulting stackmap.  This assumes a grow-down stack.
+//
+// For non-debug builds, if the stackmap would contain no pointers, no
+// stackmap is created, and nullptr is returned.  For a debug build, a
+// stackmap is always created and returned.
+static bool CreateStackMapFromLSafepoint(LSafepoint& safepoint,
+                                         const RegisterOffsets& trapExitLayout,
+                                         size_t trapExitLayoutNumWords,
+                                         size_t nInboundStackArgBytes,
+                                         wasm::StackMap** result) {
+  // Ensure this is defined on all return paths.
+  *result = nullptr;
+
+  // The size of the wasm::Frame itself.
+  const size_t nFrameBytes = sizeof(wasm::Frame);
+
+  // This is the number of bytes in the general spill area, below the Frame.
+  const size_t nBodyBytes = safepoint.framePushedAtStackMapBase();
+
+  // This is the number of bytes in the general spill area, the Frame, and the
+  // incoming args, but not including any trap (register dump) area.
+  const size_t nNonTrapBytes = nBodyBytes + nFrameBytes + nInboundStackArgBytes;
+  MOZ_ASSERT(nNonTrapBytes % sizeof(void*) == 0);
+
+  // This is the total number of bytes covered by the map.
+  const DebugOnly<size_t> nTotalBytes =
+      nNonTrapBytes +
+      (safepoint.isWasmTrap() ? (trapExitLayoutNumWords * sizeof(void*)) : 0);
+
+  // Create the stackmap initially in this vector.  Since most frames will
+  // contain 128 or fewer words, heap allocation is avoided in the majority of
+  // cases.  vec[0] is for the lowest address in the map, vec[N-1] is for the
+  // highest address in the map.
+  wasm::StackMapBoolVector vec;
+
+  // Keep track of whether we've actually seen any refs.
+  bool hasRefs = false;
+
+  // REG DUMP AREA, if any.
+  const LiveGeneralRegisterSet gcRegs = safepoint.gcRegs();
+  GeneralRegisterForwardIterator gcRegsIter(gcRegs);
+  if (safepoint.isWasmTrap()) {
+    // Deal with roots in registers.  This can only happen for safepoints
+    // associated with a trap.  For safepoints associated with a call, we
+    // don't expect to have any live values in registers, hence no roots in
+    // registers.
+    if (!vec.appendN(false, trapExitLayoutNumWords)) {
+      return false;
+    }
+    for (; gcRegsIter.more(); ++gcRegsIter) {
+      Register reg = *gcRegsIter;
+      size_t offsetFromTop = trapExitLayout.getOffset(reg);
+
+      // If this doesn't hold, the associated register wasn't saved by
+      // the trap exit stub.  Better to crash now than much later, in
+      // some obscure place, and possibly with security consequences.
+      MOZ_RELEASE_ASSERT(offsetFromTop < trapExitLayoutNumWords);
+
+      // offsetFromTop is an offset in words down from the highest
+      // address in the exit stub save area.  Switch it around to be an
+      // offset up from the bottom of the (integer register) save area.
+      size_t offsetFromBottom = trapExitLayoutNumWords - 1 - offsetFromTop;
+
+      vec[offsetFromBottom] = true;
+      hasRefs = true;
+    }
+  } else {
+    // This map is associated with a call instruction.  We expect there to be
+    // no live ref-carrying registers, and if there are we're in deep trouble.
+    MOZ_RELEASE_ASSERT(!gcRegsIter.more());
+  }
+
+  // BODY (GENERAL SPILL) AREA and FRAME and INCOMING ARGS
+  // Deal with roots on the stack.
+  size_t wordsSoFar = vec.length();
+  if (!vec.appendN(false, nNonTrapBytes / sizeof(void*))) {
+    return false;
+  }
+  const LSafepoint::SlotList& gcSlots = safepoint.gcSlots();
+  for (SafepointSlotEntry gcSlot : gcSlots) {
+    // The following needs to correspond with JitFrameLayout::slotRef
+    // gcSlot.stack == 0 means the slot is in the args area
+    if (gcSlot.stack) {
+      // It's a slot in the body allocation, so .slot is interpreted
+      // as an index downwards from the Frame*
+      MOZ_ASSERT(gcSlot.slot <= nBodyBytes);
+      uint32_t offsetInBytes = nBodyBytes - gcSlot.slot;
+      MOZ_ASSERT(offsetInBytes % sizeof(void*) == 0);
+      vec[wordsSoFar + offsetInBytes / sizeof(void*)] = true;
+    } else {
+      // It's an argument slot
+      MOZ_ASSERT(gcSlot.slot < nInboundStackArgBytes);
+      uint32_t offsetInBytes = nBodyBytes + nFrameBytes + gcSlot.slot;
+      MOZ_ASSERT(offsetInBytes % sizeof(void*) == 0);
+      vec[wordsSoFar + offsetInBytes / sizeof(void*)] = true;
+    }
+    hasRefs = true;
+  }
+
+#ifndef DEBUG
+  // We saw no references, and this is a non-debug build, so don't bother
+  // building the stackmap.
+  if (!hasRefs) {
+    return true;
+  }
+#endif
+
+  // Convert vec into a wasm::StackMap.
+  MOZ_ASSERT(vec.length() * sizeof(void*) == nTotalBytes);
+  wasm::StackMap* stackMap =
+      wasm::ConvertStackMapBoolVectorToStackMap(vec, hasRefs);
+  if (!stackMap) {
+    return false;
+  }
+  if (safepoint.isWasmTrap()) {
+    stackMap->setExitStubWords(trapExitLayoutNumWords);
+  }
+
+  // Record in the map, how far down from the highest address the Frame* is.
+  // Take the opportunity to check that we haven't marked any part of the
+  // Frame itself as a pointer.
+  stackMap->setFrameOffsetFromTop((nInboundStackArgBytes + nFrameBytes) /
+                                  sizeof(void*));
+#ifdef DEBUG
+  for (uint32_t i = 0; i < nFrameBytes / sizeof(void*); i++) {
+    MOZ_ASSERT(stackMap->getBit(stackMap->header.numMappedWords -
+                                stackMap->header.frameOffsetFromTop + i) == 0);
+  }
+#endif
+
+  *result = stackMap;
+  return true;
+}
+
+bool CodeGenerator::generateWasm(
+    wasm::CallIndirectId callIndirectId, wasm::BytecodeOffset trapOffset,
+    const wasm::ArgTypeVector& argTypes, const RegisterOffsets& trapExitLayout,
+    size_t trapExitLayoutNumWords, wasm::FuncOffsets* offsets,
+    wasm::StackMaps* stackMaps, wasm::Decoder* decoder) {
+  AutoCreatedBy acb(masm, "CodeGenerator::generateWasm");
+
+  JitSpew(JitSpew_Codegen, "# Emitting wasm code");
+
+  size_t nInboundStackArgBytes = StackArgAreaSizeUnaligned(argTypes);
+
+  wasm::GenerateFunctionPrologue(masm, callIndirectId, mozilla::Nothing(),
+                                 offsets);
+
+  MOZ_ASSERT(masm.framePushed() == 0);
+
+  // Very large frames are implausible, probably an attack.
+  if (frameSize() > wasm::MaxFrameSize) {
+    return decoder->fail(decoder->beginOffset(), "stack frame is too large");
+  }
+
+  if (omitOverRecursedCheck()) {
+    masm.reserveStack(frameSize());
+  } else {
+    std::pair<CodeOffset, uint32_t> pair =
+        masm.wasmReserveStackChecked(frameSize(), trapOffset);
+    CodeOffset trapInsnOffset = pair.first;
+    size_t nBytesReservedBeforeTrap = pair.second;
+
+    wasm::StackMap* functionEntryStackMap = nullptr;
+    if (!CreateStackMapForFunctionEntryTrap(
+            argTypes, trapExitLayout, trapExitLayoutNumWords,
+            nBytesReservedBeforeTrap, nInboundStackArgBytes,
+            &functionEntryStackMap)) {
+      return false;
+    }
+
+    // In debug builds, we'll always have a stack map, even if there are no
+    // refs to track.
+    MOZ_ASSERT(functionEntryStackMap);
+
+    if (functionEntryStackMap &&
+        !stackMaps->add((uint8_t*)(uintptr_t)trapInsnOffset.offset(),
+                        functionEntryStackMap)) {
+      functionEntryStackMap->destroy();
+      return false;
+    }
+  }
+
+  MOZ_ASSERT(masm.framePushed() == frameSize());
+
+  if (!generateBody()) {
+    return false;
+  }
+
+  masm.bind(&returnLabel_);
+  wasm::GenerateFunctionEpilogue(masm, frameSize(), offsets);
+
+  if (!generateOutOfLineCode()) {
+    return false;
+  }
+
+  masm.flush();
+  if (masm.oom()) {
+    return false;
+  }
+
+  offsets->end = masm.currentOffset();
+
+  MOZ_ASSERT(!masm.failureLabel()->used());
+  MOZ_ASSERT(snapshots_.listSize() == 0);
+  MOZ_ASSERT(snapshots_.RVATableSize() == 0);
+  MOZ_ASSERT(recovers_.size() == 0);
+  MOZ_ASSERT(graph.numConstants() == 0);
+  MOZ_ASSERT(osiIndices_.empty());
+  MOZ_ASSERT(icList_.empty());
+  MOZ_ASSERT(safepoints_.size() == 0);
+  MOZ_ASSERT(!scriptCounts_);
+
+  // Convert the safepoints to stackmaps and add them to our running
+  // collection thereof.
+  for (CodegenSafepointIndex& index : safepointIndices_) {
+    wasm::StackMap* stackMap = nullptr;
+    if (!CreateStackMapFromLSafepoint(*index.safepoint(), trapExitLayout,
+                                      trapExitLayoutNumWords,
+                                      nInboundStackArgBytes, &stackMap)) {
+      return false;
+    }
+
+    // In debug builds, we'll always have a stack map.
+    MOZ_ASSERT(stackMap);
+    if (!stackMap) {
+      continue;
+    }
+
+    if (!stackMaps->add((uint8_t*)(uintptr_t)index.displacement(), stackMap)) {
+      stackMap->destroy();
+      return false;
+    }
+  }
+
+  return true;
+}
+
+bool CodeGenerator::generate() {
+  AutoCreatedBy acb(masm, "CodeGenerator::generate");
+
+  JitSpew(JitSpew_Codegen, "# Emitting code for script %s:%u:%u",
+          gen->outerInfo().script()->filename(),
+          gen->outerInfo().script()->lineno(),
+          gen->outerInfo().script()->column());
+
+  // Initialize native code table with an entry to the start of
+  // top-level script.
+  InlineScriptTree* tree = gen->outerInfo().inlineScriptTree();
+  jsbytecode* startPC = tree->script()->code();
+  BytecodeSite* startSite = new (gen->alloc()) BytecodeSite(tree, startPC);
+  if (!addNativeToBytecodeEntry(startSite)) {
+    return false;
+  }
+
+  if (!safepoints_.init(gen->alloc())) {
+    return false;
+  }
+
+  perfSpewer_.recordOffset(masm, "Prologue");
+  if (!generatePrologue()) {
+    return false;
+  }
+
+  // Reset native => bytecode map table with top-level script and startPc.
+  if (!addNativeToBytecodeEntry(startSite)) {
+    return false;
+  }
+
+  if (!generateBody()) {
+    return false;
+  }
+
+  // Reset native => bytecode map table with top-level script and startPc.
+  if (!addNativeToBytecodeEntry(startSite)) {
+    return false;
+  }
+
+  perfSpewer_.recordOffset(masm, "Epilogue");
+  if (!generateEpilogue()) {
+    return false;
+  }
+
+  // Reset native => bytecode map table with top-level script and startPc.
+  if (!addNativeToBytecodeEntry(startSite)) {
+    return false;
+  }
+
+  perfSpewer_.recordOffset(masm, "InvalidateEpilogue");
+  generateInvalidateEpilogue();
+
+  // native => bytecode entries for OOL code will be added
+  // by CodeGeneratorShared::generateOutOfLineCode
+  perfSpewer_.recordOffset(masm, "OOLCode");
+  if (!generateOutOfLineCode()) {
+    return false;
+  }
+
+  // Add terminal entry.
+  if (!addNativeToBytecodeEntry(startSite)) {
+    return false;
+  }
+
+  // Dump Native to bytecode entries to spew.
+  dumpNativeToBytecodeEntries();
+
+  return !masm.oom();
+}
+
+static bool AddInlinedCompilations(JSContext* cx, HandleScript script,
+                                   IonCompilationId compilationId,
+                                   const WarpSnapshot* snapshot,
+                                   bool* isValid) {
+  MOZ_ASSERT(!*isValid);
+  RecompileInfo recompileInfo(script, compilationId);
+
+  JitZone* jitZone = cx->zone()->jitZone();
+
+  for (const auto* scriptSnapshot : snapshot->scripts()) {
+    JSScript* inlinedScript = scriptSnapshot->script();
+    if (inlinedScript == script) {
+      continue;
+    }
+
+    // TODO(post-Warp): This matches FinishCompilation and is necessary to
+    // ensure in-progress compilations are canceled when an inlined functon
+    // becomes a debuggee. See the breakpoint-14.js jit-test.
+    // When TI is gone, try to clean this up by moving AddInlinedCompilations to
+    // WarpOracle so that we can handle this as part of addPendingRecompile
+    // instead of requiring this separate check.
+    if (inlinedScript->isDebuggee()) {
+      *isValid = false;
+      return true;
+    }
+
+    if (!jitZone->addInlinedCompilation(recompileInfo, inlinedScript)) {
+      return false;
+    }
+  }
+
+  *isValid = true;
+  return true;
+}
+
+bool CodeGenerator::link(JSContext* cx, const WarpSnapshot* snapshot) {
+  AutoCreatedBy acb(masm, "CodeGenerator::link");
+
+  // We cancel off-thread Ion compilations in a few places during GC, but if
+  // this compilation was performed off-thread it will already have been
+  // removed from the relevant lists by this point. Don't allow GC here.
+  JS::AutoAssertNoGC nogc(cx);
+
+  RootedScript script(cx, gen->outerInfo().script());
+  MOZ_ASSERT(!script->hasIonScript());
+
+  // Perform any read barriers which were skipped while compiling the
+  // script, which may have happened off-thread.
+  const JitRealm* jr = gen->realm->jitRealm();
+  jr->performStubReadBarriers(realmStubsToReadBarrier_);
+
+  if (scriptCounts_ && !script->hasScriptCounts() &&
+      !script->initScriptCounts(cx)) {
+    return false;
+  }
+
+  IonCompilationId compilationId =
+      cx->runtime()->jitRuntime()->nextCompilationId();
+  JitZone* jitZone = cx->zone()->jitZone();
+  jitZone->currentCompilationIdRef().emplace(compilationId);
+  auto resetCurrentId = mozilla::MakeScopeExit(
+      [jitZone] { jitZone->currentCompilationIdRef().reset(); });
+
+  // Record constraints. If an error occured, returns false and potentially
+  // prevent future compilations. Otherwise, if an invalidation occured, then
+  // skip the current compilation.
+  bool isValid = false;
+
+  // If an inlined script is invalidated (for example, by attaching
+  // a debugger), we must also invalidate the parent IonScript.
+  if (!AddInlinedCompilations(cx, script, compilationId, snapshot, &isValid)) {
+    return false;
+  }
+  if (!isValid) {
+    return true;
+  }
+
+  uint32_t argumentSlots = (gen->outerInfo().nargs() + 1) * sizeof(Value);
+
+  // We encode safepoints after the OSI-point offsets have been determined.
+  if (!encodeSafepoints()) {
+    return false;
+  }
+
+  size_t numNurseryObjects = snapshot->nurseryObjects().length();
+
+  IonScript* ionScript = IonScript::New(
+      cx, compilationId, graph.localSlotsSize(), argumentSlots, frameDepth_,
+      snapshots_.listSize(), snapshots_.RVATableSize(), recovers_.size(),
+      graph.numConstants(), numNurseryObjects, safepointIndices_.length(),
+      osiIndices_.length(), icList_.length(), runtimeData_.length(),
+      safepoints_.size());
+  if (!ionScript) {
+    return false;
+  }
+#ifdef DEBUG
+  ionScript->setICHash(snapshot->icHash());
+#endif
+
+  auto freeIonScript = mozilla::MakeScopeExit([&ionScript] {
+    // Use js_free instead of IonScript::Destroy: the cache list is still
+    // uninitialized.
+    js_free(ionScript);
+  });
+
+  Linker linker(masm);
+  JitCode* code = linker.newCode(cx, CodeKind::Ion);
+  if (!code) {
+    return false;
+  }
+
+  // Encode native to bytecode map if profiling is enabled.
+  if (isProfilerInstrumentationEnabled()) {
+    // Generate native-to-bytecode main table.
+    IonEntry::ScriptList scriptList;
+    if (!generateCompactNativeToBytecodeMap(cx, code, scriptList)) {
+      return false;
+    }
+
+    uint8_t* ionTableAddr =
+        ((uint8_t*)nativeToBytecodeMap_.get()) + nativeToBytecodeTableOffset_;
+    JitcodeIonTable* ionTable = (JitcodeIonTable*)ionTableAddr;
+
+    // Construct the IonEntry that will go into the global table.
+    auto entry = MakeJitcodeGlobalEntry<IonEntry>(
+        cx, code, code->raw(), code->rawEnd(), std::move(scriptList), ionTable);
+    if (!entry) {
+      return false;
+    }
+    (void)nativeToBytecodeMap_.release();  // Table is now owned by |entry|.
+
+    // Add entry to the global table.
+    JitcodeGlobalTable* globalTable =
+        cx->runtime()->jitRuntime()->getJitcodeGlobalTable();
+    if (!globalTable->addEntry(std::move(entry))) {
+      return false;
+    }
+
+    // Mark the jitcode as having a bytecode map.
+    code->setHasBytecodeMap();
+  } else {
+    // Add a dumy jitcodeGlobalTable entry.
+    auto entry = MakeJitcodeGlobalEntry<DummyEntry>(cx, code, code->raw(),
+                                                    code->rawEnd());
+    if (!entry) {
+      return false;
+    }
+
+    // Add entry to the global table.
+    JitcodeGlobalTable* globalTable =
+        cx->runtime()->jitRuntime()->getJitcodeGlobalTable();
+    if (!globalTable->addEntry(std::move(entry))) {
+      return false;
+    }
+
+    // Mark the jitcode as having a bytecode map.
+    code->setHasBytecodeMap();
+  }
+
+  ionScript->setMethod(code);
+
+  // If the Gecko Profiler is enabled, mark IonScript as having been
+  // instrumented accordingly.
+  if (isProfilerInstrumentationEnabled()) {
+    ionScript->setHasProfilingInstrumentation();
+  }
+
+  Assembler::PatchDataWithValueCheck(
+      CodeLocationLabel(code, invalidateEpilogueData_), ImmPtr(ionScript),
+      ImmPtr((void*)-1));
+
+  for (CodeOffset offset : ionScriptLabels_) {
+    Assembler::PatchDataWithValueCheck(CodeLocationLabel(code, offset),
+                                       ImmPtr(ionScript), ImmPtr((void*)-1));
+  }
+
+  for (NurseryObjectLabel label : ionNurseryObjectLabels_) {
+    void* entry = ionScript->addressOfNurseryObject(label.nurseryIndex);
+    Assembler::PatchDataWithValueCheck(CodeLocationLabel(code, label.offset),
+                                       ImmPtr(entry), ImmPtr((void*)-1));
+  }
+
+  // for generating inline caches during the execution.
+  if (runtimeData_.length()) {
+    ionScript->copyRuntimeData(&runtimeData_[0]);
+  }
+  if (icList_.length()) {
+    ionScript->copyICEntries(&icList_[0]);
+  }
+
+  for (size_t i = 0; i < icInfo_.length(); i++) {
+    IonIC& ic = ionScript->getICFromIndex(i);
+    Assembler::PatchDataWithValueCheck(
+        CodeLocationLabel(code, icInfo_[i].icOffsetForJump),
+        ImmPtr(ic.codeRawPtr()), ImmPtr((void*)-1));
+    Assembler::PatchDataWithValueCheck(
+        CodeLocationLabel(code, icInfo_[i].icOffsetForPush), ImmPtr(&ic),
+        ImmPtr((void*)-1));
+  }
+
+  JitSpew(JitSpew_Codegen, "Created IonScript %p (raw %p)", (void*)ionScript,
+          (void*)code->raw());
+
+  ionScript->setInvalidationEpilogueDataOffset(
+      invalidateEpilogueData_.offset());
+  if (jsbytecode* osrPc = gen->outerInfo().osrPc()) {
+    ionScript->setOsrPc(osrPc);
+    ionScript->setOsrEntryOffset(getOsrEntryOffset());
+  }
+  ionScript->setInvalidationEpilogueOffset(invalidate_.offset());
+
+  perfSpewer_.saveProfile(cx, script, code);
+
+#ifdef MOZ_VTUNE
+  vtune::MarkScript(code, script, "ion");
+#endif
+
+  // for marking during GC.
+  if (safepointIndices_.length()) {
+    ionScript->copySafepointIndices(&safepointIndices_[0]);
+  }
+  if (safepoints_.size()) {
+    ionScript->copySafepoints(&safepoints_);
+  }
+
+  // for recovering from an Ion Frame.
+  if (osiIndices_.length()) {
+    ionScript->copyOsiIndices(&osiIndices_[0]);
+  }
+  if (snapshots_.listSize()) {
+    ionScript->copySnapshots(&snapshots_);
+  }
+  MOZ_ASSERT_IF(snapshots_.listSize(), recovers_.size());
+  if (recovers_.size()) {
+    ionScript->copyRecovers(&recovers_);
+  }
+  if (graph.numConstants()) {
+    const Value* vp = graph.constantPool();
+    ionScript->copyConstants(vp);
+    for (size_t i = 0; i < graph.numConstants(); i++) {
+      const Value& v = vp[i];
+      if (v.isGCThing()) {
+        if (gc::StoreBuffer* sb = v.toGCThing()->storeBuffer()) {
+          sb->putWholeCell(script);
+          break;
+        }
+      }
+    }
+  }
+
+  // Attach any generated script counts to the script.
+  if (IonScriptCounts* counts = extractScriptCounts()) {
+    script->addIonCounts(counts);
+  }
+
+  // WARNING: Code after this point must be infallible!
+
+  // Copy the list of nursery objects. Note that the store buffer can add
+  // HeapPtr edges that must be cleared in IonScript::Destroy. See the
+  // infallibility warning above.
+  const auto& nurseryObjects = snapshot->nurseryObjects();
+  for (size_t i = 0; i < nurseryObjects.length(); i++) {
+    ionScript->nurseryObjects()[i].init(nurseryObjects[i]);
+  }
+
+  // Transfer ownership of the IonScript to the JitScript. At this point enough
+  // of the IonScript must be initialized for IonScript::Destroy to work.
+  freeIonScript.release();
+  script->jitScript()->setIonScript(script, ionScript);
+
+  return true;
+}
+
+// An out-of-line path to convert a boxed int32 to either a float or double.
+class OutOfLineUnboxFloatingPoint : public OutOfLineCodeBase<CodeGenerator> {
+  LUnboxFloatingPoint* unboxFloatingPoint_;
+
+ public:
+  explicit OutOfLineUnboxFloatingPoint(LUnboxFloatingPoint* unboxFloatingPoint)
+      : unboxFloatingPoint_(unboxFloatingPoint) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineUnboxFloatingPoint(this);
+  }
+
+  LUnboxFloatingPoint* unboxFloatingPoint() const {
+    return unboxFloatingPoint_;
+  }
+};
+
+void CodeGenerator::visitUnboxFloatingPoint(LUnboxFloatingPoint* lir) {
+  const ValueOperand box = ToValue(lir, LUnboxFloatingPoint::Input);
+  const LDefinition* result = lir->output();
+
+  // Out-of-line path to convert int32 to double or bailout
+  // if this instruction is fallible.
+  OutOfLineUnboxFloatingPoint* ool =
+      new (alloc()) OutOfLineUnboxFloatingPoint(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  FloatRegister resultReg = ToFloatRegister(result);
+  masm.branchTestDouble(Assembler::NotEqual, box, ool->entry());
+  masm.unboxDouble(box, resultReg);
+  if (lir->type() == MIRType::Float32) {
+    masm.convertDoubleToFloat32(resultReg, resultReg);
+  }
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineUnboxFloatingPoint(
+    OutOfLineUnboxFloatingPoint* ool) {
+  LUnboxFloatingPoint* ins = ool->unboxFloatingPoint();
+  const ValueOperand value = ToValue(ins, LUnboxFloatingPoint::Input);
+
+  if (ins->mir()->fallible()) {
+    Label bail;
+    masm.branchTestInt32(Assembler::NotEqual, value, &bail);
+    bailoutFrom(&bail, ins->snapshot());
+  }
+  masm.int32ValueToFloatingPoint(value, ToFloatRegister(ins->output()),
+                                 ins->type());
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitCallBindVar(LCallBindVar* lir) {
+  pushArg(ToRegister(lir->environmentChain()));
+
+  using Fn = JSObject* (*)(JSContext*, JSObject*);
+  callVM<Fn, BindVarOperation>(lir);
+}
+
+void CodeGenerator::visitMegamorphicSetElement(LMegamorphicSetElement* lir) {
+  Register obj = ToRegister(lir->getOperand(0));
+  ValueOperand idVal = ToValue(lir, LMegamorphicSetElement::IndexIndex);
+  ValueOperand value = ToValue(lir, LMegamorphicSetElement::ValueIndex);
+
+  Register temp0 = ToRegister(lir->temp0());
+  // See comment in LIROps.yaml (x86 is short on registers)
+#ifndef JS_CODEGEN_X86
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+#endif
+
+  Label cacheHit, done;
+  if (JitOptions.enableWatchtowerMegamorphic) {
+#ifdef JS_CODEGEN_X86
+    masm.emitMegamorphicCachedSetSlot(
+        idVal, obj, temp0, value, &cacheHit,
+        [](MacroAssembler& masm, const Address& addr, MIRType mirType) {
+          EmitPreBarrier(masm, addr, mirType);
+        });
+#else
+    masm.emitMegamorphicCachedSetSlot(
+        idVal, obj, temp0, temp1, temp2, value, &cacheHit,
+        [](MacroAssembler& masm, const Address& addr, MIRType mirType) {
+          EmitPreBarrier(masm, addr, mirType);
+        });
+#endif
+  }
+
+  pushArg(Imm32(lir->mir()->strict()));
+  pushArg(ToValue(lir, LMegamorphicSetElement::ValueIndex));
+  pushArg(ToValue(lir, LMegamorphicSetElement::IndexIndex));
+  pushArg(obj);
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleValue, HandleValue, bool);
+  callVM<Fn, js::jit::SetElementMegamorphic<true>>(lir);
+
+  masm.jump(&done);
+  masm.bind(&cacheHit);
+
+  masm.branchPtrInNurseryChunk(Assembler::Equal, obj, temp0, &done);
+  masm.branchValueIsNurseryCell(Assembler::NotEqual, value, temp0, &done);
+
+  saveVolatile(temp0);
+  emitPostWriteBarrier(obj);
+  restoreVolatile(temp0);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitLoadFixedSlotV(LLoadFixedSlotV* ins) {
+  const Register obj = ToRegister(ins->getOperand(0));
+  size_t slot = ins->mir()->slot();
+  ValueOperand result = ToOutValue(ins);
+
+  masm.loadValue(Address(obj, NativeObject::getFixedSlotOffset(slot)), result);
+}
+
+void CodeGenerator::visitLoadFixedSlotT(LLoadFixedSlotT* ins) {
+  const Register obj = ToRegister(ins->getOperand(0));
+  size_t slot = ins->mir()->slot();
+  AnyRegister result = ToAnyRegister(ins->getDef(0));
+  MIRType type = ins->mir()->type();
+
+  masm.loadUnboxedValue(Address(obj, NativeObject::getFixedSlotOffset(slot)),
+                        type, result);
+}
+
+template <typename T>
+static void EmitLoadAndUnbox(MacroAssembler& masm, const T& src, MIRType type,
+                             bool fallible, AnyRegister dest, Label* fail) {
+  if (type == MIRType::Double) {
+    MOZ_ASSERT(dest.isFloat());
+    masm.ensureDouble(src, dest.fpu(), fail);
+    return;
+  }
+  if (fallible) {
+    switch (type) {
+      case MIRType::Int32:
+        masm.fallibleUnboxInt32(src, dest.gpr(), fail);
+        break;
+      case MIRType::Boolean:
+        masm.fallibleUnboxBoolean(src, dest.gpr(), fail);
+        break;
+      case MIRType::Object:
+        masm.fallibleUnboxObject(src, dest.gpr(), fail);
+        break;
+      case MIRType::String:
+        masm.fallibleUnboxString(src, dest.gpr(), fail);
+        break;
+      case MIRType::Symbol:
+        masm.fallibleUnboxSymbol(src, dest.gpr(), fail);
+        break;
+      case MIRType::BigInt:
+        masm.fallibleUnboxBigInt(src, dest.gpr(), fail);
+        break;
+      default:
+        MOZ_CRASH("Unexpected MIRType");
+    }
+    return;
+  }
+  masm.loadUnboxedValue(src, type, dest);
+}
+
+void CodeGenerator::visitLoadFixedSlotAndUnbox(LLoadFixedSlotAndUnbox* ins) {
+  const MLoadFixedSlotAndUnbox* mir = ins->mir();
+  MIRType type = mir->type();
+  Register input = ToRegister(ins->object());
+  AnyRegister result = ToAnyRegister(ins->output());
+  size_t slot = mir->slot();
+
+  Address address(input, NativeObject::getFixedSlotOffset(slot));
+
+  Label bail;
+  EmitLoadAndUnbox(masm, address, type, mir->fallible(), result, &bail);
+  if (mir->fallible()) {
+    bailoutFrom(&bail, ins->snapshot());
+  }
+}
+
+void CodeGenerator::visitLoadDynamicSlotAndUnbox(
+    LLoadDynamicSlotAndUnbox* ins) {
+  const MLoadDynamicSlotAndUnbox* mir = ins->mir();
+  MIRType type = mir->type();
+  Register input = ToRegister(ins->slots());
+  AnyRegister result = ToAnyRegister(ins->output());
+  size_t slot = mir->slot();
+
+  Address address(input, slot * sizeof(JS::Value));
+
+  Label bail;
+  EmitLoadAndUnbox(masm, address, type, mir->fallible(), result, &bail);
+  if (mir->fallible()) {
+    bailoutFrom(&bail, ins->snapshot());
+  }
+}
+
+void CodeGenerator::visitLoadElementAndUnbox(LLoadElementAndUnbox* ins) {
+  const MLoadElementAndUnbox* mir = ins->mir();
+  MIRType type = mir->type();
+  Register elements = ToRegister(ins->elements());
+  AnyRegister result = ToAnyRegister(ins->output());
+
+  Label bail;
+  if (ins->index()->isConstant()) {
+    NativeObject::elementsSizeMustNotOverflow();
+    int32_t offset = ToInt32(ins->index()) * sizeof(Value);
+    Address address(elements, offset);
+    EmitLoadAndUnbox(masm, address, type, mir->fallible(), result, &bail);
+  } else {
+    BaseObjectElementIndex address(elements, ToRegister(ins->index()));
+    EmitLoadAndUnbox(masm, address, type, mir->fallible(), result, &bail);
+  }
+
+  if (mir->fallible()) {
+    bailoutFrom(&bail, ins->snapshot());
+  }
+}
+
+void CodeGenerator::visitAddAndStoreSlot(LAddAndStoreSlot* ins) {
+  const Register obj = ToRegister(ins->getOperand(0));
+  const ValueOperand value = ToValue(ins, LAddAndStoreSlot::ValueIndex);
+  const Register maybeTemp = ToTempRegisterOrInvalid(ins->temp0());
+
+  Shape* shape = ins->mir()->shape();
+  masm.storeObjShape(shape, obj, [](MacroAssembler& masm, const Address& addr) {
+    EmitPreBarrier(masm, addr, MIRType::Shape);
+  });
+
+  // Perform the store. No pre-barrier required since this is a new
+  // initialization.
+
+  uint32_t offset = ins->mir()->slotOffset();
+  if (ins->mir()->kind() == MAddAndStoreSlot::Kind::FixedSlot) {
+    Address slot(obj, offset);
+    masm.storeValue(value, slot);
+  } else {
+    masm.loadPtr(Address(obj, NativeObject::offsetOfSlots()), maybeTemp);
+    Address slot(maybeTemp, offset);
+    masm.storeValue(value, slot);
+  }
+}
+
+void CodeGenerator::visitAllocateAndStoreSlot(LAllocateAndStoreSlot* ins) {
+  const Register obj = ToRegister(ins->getOperand(0));
+  const ValueOperand value = ToValue(ins, LAllocateAndStoreSlot::ValueIndex);
+  const Register temp0 = ToRegister(ins->temp0());
+  const Register temp1 = ToRegister(ins->temp1());
+
+  masm.Push(obj);
+  masm.Push(value);
+
+  using Fn = bool (*)(JSContext* cx, NativeObject* obj, uint32_t newCount);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp0);
+  masm.passABIArg(temp0);
+  masm.passABIArg(obj);
+  masm.move32(Imm32(ins->mir()->numNewSlots()), temp1);
+  masm.passABIArg(temp1);
+  masm.callWithABI<Fn, NativeObject::growSlotsPure>();
+  masm.storeCallPointerResult(temp0);
+
+  masm.Pop(value);
+  masm.Pop(obj);
+
+  bailoutIfFalseBool(temp0, ins->snapshot());
+
+  masm.storeObjShape(ins->mir()->shape(), obj,
+                     [](MacroAssembler& masm, const Address& addr) {
+                       EmitPreBarrier(masm, addr, MIRType::Shape);
+                     });
+
+  // Perform the store. No pre-barrier required since this is a new
+  // initialization.
+  masm.loadPtr(Address(obj, NativeObject::offsetOfSlots()), temp0);
+  Address slot(temp0, ins->mir()->slotOffset());
+  masm.storeValue(value, slot);
+}
+
+void CodeGenerator::visitAddSlotAndCallAddPropHook(
+    LAddSlotAndCallAddPropHook* ins) {
+  const Register obj = ToRegister(ins->object());
+  const ValueOperand value =
+      ToValue(ins, LAddSlotAndCallAddPropHook::ValueIndex);
+
+  pushArg(ImmGCPtr(ins->mir()->shape()));
+  pushArg(value);
+  pushArg(obj);
+
+  using Fn =
+      bool (*)(JSContext*, Handle<NativeObject*>, HandleValue, Handle<Shape*>);
+  callVM<Fn, AddSlotAndCallAddPropHook>(ins);
+}
+
+void CodeGenerator::visitStoreFixedSlotV(LStoreFixedSlotV* ins) {
+  const Register obj = ToRegister(ins->getOperand(0));
+  size_t slot = ins->mir()->slot();
+
+  const ValueOperand value = ToValue(ins, LStoreFixedSlotV::ValueIndex);
+
+  Address address(obj, NativeObject::getFixedSlotOffset(slot));
+  if (ins->mir()->needsBarrier()) {
+    emitPreBarrier(address);
+  }
+
+  masm.storeValue(value, address);
+}
+
+void CodeGenerator::visitStoreFixedSlotT(LStoreFixedSlotT* ins) {
+  const Register obj = ToRegister(ins->getOperand(0));
+  size_t slot = ins->mir()->slot();
+
+  const LAllocation* value = ins->value();
+  MIRType valueType = ins->mir()->value()->type();
+
+  Address address(obj, NativeObject::getFixedSlotOffset(slot));
+  if (ins->mir()->needsBarrier()) {
+    emitPreBarrier(address);
+  }
+
+  ConstantOrRegister nvalue =
+      value->isConstant()
+          ? ConstantOrRegister(value->toConstant()->toJSValue())
+          : TypedOrValueRegister(valueType, ToAnyRegister(value));
+  masm.storeConstantOrRegister(nvalue, address);
+}
+
+void CodeGenerator::visitGetNameCache(LGetNameCache* ins) {
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+  Register envChain = ToRegister(ins->envObj());
+  ValueOperand output = ToOutValue(ins);
+  Register temp = ToRegister(ins->temp0());
+
+  IonGetNameIC ic(liveRegs, envChain, output, temp);
+  addIC(ins, allocateIC(ic));
+}
+
+void CodeGenerator::addGetPropertyCache(LInstruction* ins,
+                                        LiveRegisterSet liveRegs,
+                                        TypedOrValueRegister value,
+                                        const ConstantOrRegister& id,
+                                        ValueOperand output) {
+  CacheKind kind = CacheKind::GetElem;
+  if (id.constant() && id.value().isString()) {
+    JSString* idString = id.value().toString();
+    if (idString->isAtom() && !idString->asAtom().isIndex()) {
+      kind = CacheKind::GetProp;
+    }
+  }
+  IonGetPropertyIC cache(kind, liveRegs, value, id, output);
+  addIC(ins, allocateIC(cache));
+}
+
+void CodeGenerator::addSetPropertyCache(LInstruction* ins,
+                                        LiveRegisterSet liveRegs,
+                                        Register objReg, Register temp,
+                                        const ConstantOrRegister& id,
+                                        const ConstantOrRegister& value,
+                                        bool strict) {
+  CacheKind kind = CacheKind::SetElem;
+  if (id.constant() && id.value().isString()) {
+    JSString* idString = id.value().toString();
+    if (idString->isAtom() && !idString->asAtom().isIndex()) {
+      kind = CacheKind::SetProp;
+    }
+  }
+  IonSetPropertyIC cache(kind, liveRegs, objReg, temp, id, value, strict);
+  addIC(ins, allocateIC(cache));
+}
+
+ConstantOrRegister CodeGenerator::toConstantOrRegister(LInstruction* lir,
+                                                       size_t n, MIRType type) {
+  if (type == MIRType::Value) {
+    return TypedOrValueRegister(ToValue(lir, n));
+  }
+
+  const LAllocation* value = lir->getOperand(n);
+  if (value->isConstant()) {
+    return ConstantOrRegister(value->toConstant()->toJSValue());
+  }
+
+  return TypedOrValueRegister(type, ToAnyRegister(value));
+}
+
+void CodeGenerator::visitGetPropertyCache(LGetPropertyCache* ins) {
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+  TypedOrValueRegister value =
+      toConstantOrRegister(ins, LGetPropertyCache::ValueIndex,
+                           ins->mir()->value()->type())
+          .reg();
+  ConstantOrRegister id = toConstantOrRegister(ins, LGetPropertyCache::IdIndex,
+                                               ins->mir()->idval()->type());
+  ValueOperand output = ToOutValue(ins);
+  addGetPropertyCache(ins, liveRegs, value, id, output);
+}
+
+void CodeGenerator::visitGetPropSuperCache(LGetPropSuperCache* ins) {
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+  Register obj = ToRegister(ins->obj());
+  TypedOrValueRegister receiver =
+      toConstantOrRegister(ins, LGetPropSuperCache::ReceiverIndex,
+                           ins->mir()->receiver()->type())
+          .reg();
+  ConstantOrRegister id = toConstantOrRegister(ins, LGetPropSuperCache::IdIndex,
+                                               ins->mir()->idval()->type());
+  ValueOperand output = ToOutValue(ins);
+
+  CacheKind kind = CacheKind::GetElemSuper;
+  if (id.constant() && id.value().isString()) {
+    JSString* idString = id.value().toString();
+    if (idString->isAtom() && !idString->asAtom().isIndex()) {
+      kind = CacheKind::GetPropSuper;
+    }
+  }
+
+  IonGetPropSuperIC cache(kind, liveRegs, obj, receiver, id, output);
+  addIC(ins, allocateIC(cache));
+}
+
+void CodeGenerator::visitBindNameCache(LBindNameCache* ins) {
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+  Register envChain = ToRegister(ins->environmentChain());
+  Register output = ToRegister(ins->output());
+  Register temp = ToRegister(ins->temp0());
+
+  IonBindNameIC ic(liveRegs, envChain, output, temp);
+  addIC(ins, allocateIC(ic));
+}
+
+void CodeGenerator::visitHasOwnCache(LHasOwnCache* ins) {
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+  TypedOrValueRegister value =
+      toConstantOrRegister(ins, LHasOwnCache::ValueIndex,
+                           ins->mir()->value()->type())
+          .reg();
+  TypedOrValueRegister id = toConstantOrRegister(ins, LHasOwnCache::IdIndex,
+                                                 ins->mir()->idval()->type())
+                                .reg();
+  Register output = ToRegister(ins->output());
+
+  IonHasOwnIC cache(liveRegs, value, id, output);
+  addIC(ins, allocateIC(cache));
+}
+
+void CodeGenerator::visitCheckPrivateFieldCache(LCheckPrivateFieldCache* ins) {
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+  TypedOrValueRegister value =
+      toConstantOrRegister(ins, LCheckPrivateFieldCache::ValueIndex,
+                           ins->mir()->value()->type())
+          .reg();
+  TypedOrValueRegister id =
+      toConstantOrRegister(ins, LCheckPrivateFieldCache::IdIndex,
+                           ins->mir()->idval()->type())
+          .reg();
+  Register output = ToRegister(ins->output());
+
+  IonCheckPrivateFieldIC cache(liveRegs, value, id, output);
+  addIC(ins, allocateIC(cache));
+}
+
+void CodeGenerator::visitNewPrivateName(LNewPrivateName* ins) {
+  pushArg(ImmGCPtr(ins->mir()->name()));
+
+  using Fn = JS::Symbol* (*)(JSContext*, Handle<JSAtom*>);
+  callVM<Fn, NewPrivateName>(ins);
+}
+
+void CodeGenerator::visitCallDeleteProperty(LCallDeleteProperty* lir) {
+  pushArg(ImmGCPtr(lir->mir()->name()));
+  pushArg(ToValue(lir, LCallDeleteProperty::ValueIndex));
+
+  using Fn = bool (*)(JSContext*, HandleValue, Handle<PropertyName*>, bool*);
+  if (lir->mir()->strict()) {
+    callVM<Fn, DelPropOperation<true>>(lir);
+  } else {
+    callVM<Fn, DelPropOperation<false>>(lir);
+  }
+}
+
+void CodeGenerator::visitCallDeleteElement(LCallDeleteElement* lir) {
+  pushArg(ToValue(lir, LCallDeleteElement::IndexIndex));
+  pushArg(ToValue(lir, LCallDeleteElement::ValueIndex));
+
+  using Fn = bool (*)(JSContext*, HandleValue, HandleValue, bool*);
+  if (lir->mir()->strict()) {
+    callVM<Fn, DelElemOperation<true>>(lir);
+  } else {
+    callVM<Fn, DelElemOperation<false>>(lir);
+  }
+}
+
+void CodeGenerator::visitObjectToIterator(LObjectToIterator* lir) {
+  Register obj = ToRegister(lir->object());
+  Register iterObj = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+  Register temp2 = ToRegister(lir->temp1());
+  Register temp3 = ToRegister(lir->temp2());
+
+  using Fn = PropertyIteratorObject* (*)(JSContext*, HandleObject);
+  OutOfLineCode* ool = (lir->mir()->wantsIndices())
+                           ? oolCallVM<Fn, GetIteratorWithIndices>(
+                                 lir, ArgList(obj), StoreRegisterTo(iterObj))
+                           : oolCallVM<Fn, GetIterator>(
+                                 lir, ArgList(obj), StoreRegisterTo(iterObj));
+
+  masm.maybeLoadIteratorFromShape(obj, iterObj, temp, temp2, temp3,
+                                  ool->entry());
+
+  Register nativeIter = temp;
+  masm.loadPrivate(
+      Address(iterObj, PropertyIteratorObject::offsetOfIteratorSlot()),
+      nativeIter);
+
+  if (lir->mir()->wantsIndices()) {
+    // At least one consumer of the output of this iterator has been optimized
+    // to use iterator indices. If the cached iterator doesn't include indices,
+    // but it was marked to indicate that we can create them if needed, then we
+    // do a VM call to replace the cached iterator with a fresh iterator
+    // including indices.
+    masm.branchNativeIteratorIndices(Assembler::Equal, nativeIter, temp2,
+                                     NativeIteratorIndices::AvailableOnRequest,
+                                     ool->entry());
+  }
+
+  Address iterFlagsAddr(nativeIter, NativeIterator::offsetOfFlagsAndCount());
+  masm.storePtr(
+      obj, Address(nativeIter, NativeIterator::offsetOfObjectBeingIterated()));
+  masm.or32(Imm32(NativeIterator::Flags::Active), iterFlagsAddr);
+
+  Register enumeratorsAddr = temp2;
+  masm.movePtr(ImmPtr(lir->mir()->enumeratorsAddr()), enumeratorsAddr);
+  masm.registerIterator(enumeratorsAddr, nativeIter, temp3);
+
+  // Generate post-write barrier for storing to |iterObj->objectBeingIterated_|.
+  // We already know that |iterObj| is tenured, so we only have to check |obj|.
+  Label skipBarrier;
+  masm.branchPtrInNurseryChunk(Assembler::NotEqual, obj, temp2, &skipBarrier);
+  {
+    LiveRegisterSet save = liveVolatileRegs(lir);
+    save.takeUnchecked(temp);
+    save.takeUnchecked(temp2);
+    save.takeUnchecked(temp3);
+    if (iterObj.volatile_()) {
+      save.addUnchecked(iterObj);
+    }
+
+    masm.PushRegsInMask(save);
+    emitPostWriteBarrier(iterObj);
+    masm.PopRegsInMask(save);
+  }
+  masm.bind(&skipBarrier);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitValueToIterator(LValueToIterator* lir) {
+  pushArg(ToValue(lir, LValueToIterator::ValueIndex));
+
+  using Fn = PropertyIteratorObject* (*)(JSContext*, HandleValue);
+  callVM<Fn, ValueToIterator>(lir);
+}
+
+void CodeGenerator::visitIteratorHasIndicesAndBranch(
+    LIteratorHasIndicesAndBranch* lir) {
+  Register iterator = ToRegister(lir->iterator());
+  Register object = ToRegister(lir->object());
+  Register temp = ToRegister(lir->temp());
+  Register temp2 = ToRegister(lir->temp2());
+  Label* ifTrue = getJumpLabelForBranch(lir->ifTrue());
+  Label* ifFalse = getJumpLabelForBranch(lir->ifFalse());
+
+  // Check that the iterator has indices available.
+  Address nativeIterAddr(iterator,
+                         PropertyIteratorObject::offsetOfIteratorSlot());
+  masm.loadPrivate(nativeIterAddr, temp);
+  masm.branchNativeIteratorIndices(Assembler::NotEqual, temp, temp2,
+                                   NativeIteratorIndices::Valid, ifFalse);
+
+  // Guard that the first shape stored in the iterator matches the current
+  // shape of the iterated object.
+  Address firstShapeAddr(temp, NativeIterator::offsetOfFirstShape());
+  masm.loadPtr(firstShapeAddr, temp);
+  masm.branchTestObjShape(Assembler::NotEqual, object, temp, temp2, object,
+                          ifFalse);
+
+  if (!isNextBlock(lir->ifTrue()->lir())) {
+    masm.jump(ifTrue);
+  }
+}
+
+void CodeGenerator::visitLoadSlotByIteratorIndex(
+    LLoadSlotByIteratorIndex* lir) {
+  Register object = ToRegister(lir->object());
+  Register iterator = ToRegister(lir->iterator());
+  Register temp = ToRegister(lir->temp0());
+  Register temp2 = ToRegister(lir->temp1());
+  ValueOperand result = ToOutValue(lir);
+
+  masm.extractCurrentIndexAndKindFromIterator(iterator, temp, temp2);
+
+  Label notDynamicSlot, notFixedSlot, done;
+  masm.branch32(Assembler::NotEqual, temp2,
+                Imm32(uint32_t(PropertyIndex::Kind::DynamicSlot)),
+                &notDynamicSlot);
+  masm.loadPtr(Address(object, NativeObject::offsetOfSlots()), temp2);
+  masm.loadValue(BaseValueIndex(temp2, temp), result);
+  masm.jump(&done);
+
+  masm.bind(&notDynamicSlot);
+  masm.branch32(Assembler::NotEqual, temp2,
+                Imm32(uint32_t(PropertyIndex::Kind::FixedSlot)), &notFixedSlot);
+  // Fixed slot
+  masm.loadValue(BaseValueIndex(object, temp, sizeof(NativeObject)), result);
+  masm.jump(&done);
+  masm.bind(&notFixedSlot);
+
+#ifdef DEBUG
+  Label kindOkay;
+  masm.branch32(Assembler::Equal, temp2,
+                Imm32(uint32_t(PropertyIndex::Kind::Element)), &kindOkay);
+  masm.assumeUnreachable("Invalid PropertyIndex::Kind");
+  masm.bind(&kindOkay);
+#endif
+
+  // Dense element
+  masm.loadPtr(Address(object, NativeObject::offsetOfElements()), temp2);
+  Label indexOkay;
+  Address initLength(temp2, ObjectElements::offsetOfInitializedLength());
+  masm.branch32(Assembler::Above, initLength, temp, &indexOkay);
+  masm.assumeUnreachable("Dense element out of bounds");
+  masm.bind(&indexOkay);
+
+  masm.loadValue(BaseObjectElementIndex(temp2, temp), result);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitStoreSlotByIteratorIndex(
+    LStoreSlotByIteratorIndex* lir) {
+  Register object = ToRegister(lir->object());
+  Register iterator = ToRegister(lir->iterator());
+  ValueOperand value = ToValue(lir, LStoreSlotByIteratorIndex::ValueIndex);
+  Register temp = ToRegister(lir->temp0());
+  Register temp2 = ToRegister(lir->temp1());
+
+  masm.extractCurrentIndexAndKindFromIterator(iterator, temp, temp2);
+
+  Label notDynamicSlot, notFixedSlot, done, doStore;
+  masm.branch32(Assembler::NotEqual, temp2,
+                Imm32(uint32_t(PropertyIndex::Kind::DynamicSlot)),
+                &notDynamicSlot);
+  masm.loadPtr(Address(object, NativeObject::offsetOfSlots()), temp2);
+  masm.computeEffectiveAddress(BaseValueIndex(temp2, temp), temp);
+  masm.jump(&doStore);
+
+  masm.bind(&notDynamicSlot);
+  masm.branch32(Assembler::NotEqual, temp2,
+                Imm32(uint32_t(PropertyIndex::Kind::FixedSlot)), &notFixedSlot);
+  // Fixed slot
+  masm.computeEffectiveAddress(
+      BaseValueIndex(object, temp, sizeof(NativeObject)), temp);
+  masm.jump(&doStore);
+  masm.bind(&notFixedSlot);
+
+#ifdef DEBUG
+  Label kindOkay;
+  masm.branch32(Assembler::Equal, temp2,
+                Imm32(uint32_t(PropertyIndex::Kind::Element)), &kindOkay);
+  masm.assumeUnreachable("Invalid PropertyIndex::Kind");
+  masm.bind(&kindOkay);
+#endif
+
+  // Dense element
+  masm.loadPtr(Address(object, NativeObject::offsetOfElements()), temp2);
+  Label indexOkay;
+  Address initLength(temp2, ObjectElements::offsetOfInitializedLength());
+  masm.branch32(Assembler::Above, initLength, temp, &indexOkay);
+  masm.assumeUnreachable("Dense element out of bounds");
+  masm.bind(&indexOkay);
+
+  BaseObjectElementIndex elementAddress(temp2, temp);
+  masm.computeEffectiveAddress(elementAddress, temp);
+
+  masm.bind(&doStore);
+  Address storeAddress(temp, 0);
+  emitPreBarrier(storeAddress);
+  masm.storeValue(value, storeAddress);
+
+  masm.branchPtrInNurseryChunk(Assembler::Equal, object, temp2, &done);
+  masm.branchValueIsNurseryCell(Assembler::NotEqual, value, temp2, &done);
+
+  saveVolatile(temp2);
+  emitPostWriteBarrier(object);
+  restoreVolatile(temp2);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitSetPropertyCache(LSetPropertyCache* ins) {
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+  Register objReg = ToRegister(ins->object());
+  Register temp = ToRegister(ins->temp0());
+
+  ConstantOrRegister id = toConstantOrRegister(ins, LSetPropertyCache::IdIndex,
+                                               ins->mir()->idval()->type());
+  ConstantOrRegister value = toConstantOrRegister(
+      ins, LSetPropertyCache::ValueIndex, ins->mir()->value()->type());
+
+  addSetPropertyCache(ins, liveRegs, objReg, temp, id, value,
+                      ins->mir()->strict());
+}
+
+void CodeGenerator::visitThrow(LThrow* lir) {
+  pushArg(ToValue(lir, LThrow::ValueIndex));
+
+  using Fn = bool (*)(JSContext*, HandleValue);
+  callVM<Fn, js::ThrowOperation>(lir);
+}
+
+class OutOfLineTypeOfV : public OutOfLineCodeBase<CodeGenerator> {
+  LTypeOfV* ins_;
+
+ public:
+  explicit OutOfLineTypeOfV(LTypeOfV* ins) : ins_(ins) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineTypeOfV(this);
+  }
+  LTypeOfV* ins() const { return ins_; }
+};
+
+void CodeGenerator::emitTypeOfJSType(JSValueType type, Register output) {
+  switch (type) {
+    case JSVAL_TYPE_OBJECT:
+      masm.move32(Imm32(JSTYPE_OBJECT), output);
+      break;
+    case JSVAL_TYPE_DOUBLE:
+    case JSVAL_TYPE_INT32:
+      masm.move32(Imm32(JSTYPE_NUMBER), output);
+      break;
+    case JSVAL_TYPE_BOOLEAN:
+      masm.move32(Imm32(JSTYPE_BOOLEAN), output);
+      break;
+    case JSVAL_TYPE_UNDEFINED:
+      masm.move32(Imm32(JSTYPE_UNDEFINED), output);
+      break;
+    case JSVAL_TYPE_NULL:
+      masm.move32(Imm32(JSTYPE_OBJECT), output);
+      break;
+    case JSVAL_TYPE_STRING:
+      masm.move32(Imm32(JSTYPE_STRING), output);
+      break;
+    case JSVAL_TYPE_SYMBOL:
+      masm.move32(Imm32(JSTYPE_SYMBOL), output);
+      break;
+    case JSVAL_TYPE_BIGINT:
+      masm.move32(Imm32(JSTYPE_BIGINT), output);
+      break;
+    default:
+      MOZ_CRASH("Unsupported JSValueType");
+  }
+}
+
+void CodeGenerator::emitTypeOfCheck(JSValueType type, Register tag,
+                                    Register output, Label* done,
+                                    Label* oolObject) {
+  Label notMatch;
+  switch (type) {
+    case JSVAL_TYPE_OBJECT:
+      // The input may be a callable object (result is "function") or
+      // may emulate undefined (result is "undefined"). Use an OOL path.
+      masm.branchTestObject(Assembler::Equal, tag, oolObject);
+      return;
+    case JSVAL_TYPE_DOUBLE:
+    case JSVAL_TYPE_INT32:
+      masm.branchTestNumber(Assembler::NotEqual, tag, &notMatch);
+      break;
+    default:
+      masm.branchTestType(Assembler::NotEqual, tag, type, &notMatch);
+      break;
+  }
+
+  emitTypeOfJSType(type, output);
+  masm.jump(done);
+  masm.bind(&notMatch);
+}
+
+void CodeGenerator::visitTypeOfV(LTypeOfV* lir) {
+  const ValueOperand value = ToValue(lir, LTypeOfV::InputIndex);
+  Register output = ToRegister(lir->output());
+  Register tag = masm.extractTag(value, output);
+
+  Label done;
+
+  auto* ool = new (alloc()) OutOfLineTypeOfV(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  const std::initializer_list<JSValueType> defaultOrder = {
+      JSVAL_TYPE_OBJECT, JSVAL_TYPE_DOUBLE,  JSVAL_TYPE_UNDEFINED,
+      JSVAL_TYPE_NULL,   JSVAL_TYPE_BOOLEAN, JSVAL_TYPE_STRING,
+      JSVAL_TYPE_SYMBOL, JSVAL_TYPE_BIGINT};
+
+  mozilla::EnumSet<JSValueType, uint32_t> remaining(defaultOrder);
+
+  // Generate checks for previously observed types first.
+  // The TypeDataList is sorted by descending frequency.
+  for (auto& observed : lir->mir()->observedTypes()) {
+    JSValueType type = observed.type();
+
+    // Unify number types.
+    if (type == JSVAL_TYPE_INT32) {
+      type = JSVAL_TYPE_DOUBLE;
+    }
+
+    remaining -= type;
+
+    emitTypeOfCheck(type, tag, output, &done, ool->entry());
+  }
+
+  // Generate checks for remaining types.
+  for (auto type : defaultOrder) {
+    if (!remaining.contains(type)) {
+      continue;
+    }
+    remaining -= type;
+
+    if (remaining.isEmpty() && type != JSVAL_TYPE_OBJECT) {
+      // We can skip the check for the last remaining type, unless the type is
+      // JSVAL_TYPE_OBJECT, which may have to go through the OOL path.
+#ifdef DEBUG
+      emitTypeOfCheck(type, tag, output, &done, ool->entry());
+      masm.assumeUnreachable("Unexpected Value type in visitTypeOfV");
+#else
+      emitTypeOfJSType(type, output);
+#endif
+    } else {
+      emitTypeOfCheck(type, tag, output, &done, ool->entry());
+    }
+  }
+  MOZ_ASSERT(remaining.isEmpty());
+
+  masm.bind(&done);
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::emitTypeOfObject(Register obj, Register output,
+                                     Label* done) {
+  Label slowCheck, isObject, isCallable, isUndefined;
+  masm.typeOfObject(obj, output, &slowCheck, &isObject, &isCallable,
+                    &isUndefined);
+
+  masm.bind(&isCallable);
+  masm.move32(Imm32(JSTYPE_FUNCTION), output);
+  masm.jump(done);
+
+  masm.bind(&isUndefined);
+  masm.move32(Imm32(JSTYPE_UNDEFINED), output);
+  masm.jump(done);
+
+  masm.bind(&isObject);
+  masm.move32(Imm32(JSTYPE_OBJECT), output);
+  masm.jump(done);
+
+  masm.bind(&slowCheck);
+
+  saveVolatile(output);
+  using Fn = JSType (*)(JSObject*);
+  masm.setupAlignedABICall();
+  masm.passABIArg(obj);
+  masm.callWithABI<Fn, js::TypeOfObject>();
+  masm.storeCallInt32Result(output);
+  restoreVolatile(output);
+}
+
+void CodeGenerator::visitOutOfLineTypeOfV(OutOfLineTypeOfV* ool) {
+  LTypeOfV* ins = ool->ins();
+
+  ValueOperand input = ToValue(ins, LTypeOfV::InputIndex);
+  Register temp = ToTempUnboxRegister(ins->temp0());
+  Register output = ToRegister(ins->output());
+
+  Register obj = masm.extractObject(input, temp);
+  emitTypeOfObject(obj, output, ool->rejoin());
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitTypeOfO(LTypeOfO* lir) {
+  Register obj = ToRegister(lir->object());
+  Register output = ToRegister(lir->output());
+
+  Label done;
+  emitTypeOfObject(obj, output, &done);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitTypeOfName(LTypeOfName* lir) {
+  Register input = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+#ifdef DEBUG
+  Label ok;
+  masm.branch32(Assembler::Below, input, Imm32(JSTYPE_LIMIT), &ok);
+  masm.assumeUnreachable("bad JSType");
+  masm.bind(&ok);
+#endif
+
+  static_assert(JSTYPE_UNDEFINED == 0);
+
+  masm.movePtr(ImmPtr(&gen->runtime->names().undefined), output);
+  masm.loadPtr(BaseIndex(output, input, ScalePointer), output);
+}
+
+class OutOfLineTypeOfIsNonPrimitiveV : public OutOfLineCodeBase<CodeGenerator> {
+  LTypeOfIsNonPrimitiveV* ins_;
+
+ public:
+  explicit OutOfLineTypeOfIsNonPrimitiveV(LTypeOfIsNonPrimitiveV* ins)
+      : ins_(ins) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineTypeOfIsNonPrimitiveV(this);
+  }
+  auto* ins() const { return ins_; }
+};
+
+class OutOfLineTypeOfIsNonPrimitiveO : public OutOfLineCodeBase<CodeGenerator> {
+  LTypeOfIsNonPrimitiveO* ins_;
+
+ public:
+  explicit OutOfLineTypeOfIsNonPrimitiveO(LTypeOfIsNonPrimitiveO* ins)
+      : ins_(ins) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineTypeOfIsNonPrimitiveO(this);
+  }
+  auto* ins() const { return ins_; }
+};
+
+void CodeGenerator::emitTypeOfIsObjectOOL(MTypeOfIs* mir, Register obj,
+                                          Register output) {
+  saveVolatile(output);
+  using Fn = JSType (*)(JSObject*);
+  masm.setupAlignedABICall();
+  masm.passABIArg(obj);
+  masm.callWithABI<Fn, js::TypeOfObject>();
+  masm.storeCallInt32Result(output);
+  restoreVolatile(output);
+
+  auto cond = JSOpToCondition(mir->jsop(), /* isSigned = */ false);
+  masm.cmp32Set(cond, output, Imm32(mir->jstype()), output);
+}
+
+void CodeGenerator::visitOutOfLineTypeOfIsNonPrimitiveV(
+    OutOfLineTypeOfIsNonPrimitiveV* ool) {
+  auto* ins = ool->ins();
+  ValueOperand input = ToValue(ins, LTypeOfIsNonPrimitiveV::InputIndex);
+  Register output = ToRegister(ins->output());
+  Register temp = ToTempUnboxRegister(ins->temp0());
+
+  Register obj = masm.extractObject(input, temp);
+
+  emitTypeOfIsObjectOOL(ins->mir(), obj, output);
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineTypeOfIsNonPrimitiveO(
+    OutOfLineTypeOfIsNonPrimitiveO* ool) {
+  auto* ins = ool->ins();
+  Register input = ToRegister(ins->input());
+  Register output = ToRegister(ins->output());
+
+  emitTypeOfIsObjectOOL(ins->mir(), input, output);
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::emitTypeOfIsObject(MTypeOfIs* mir, Register obj,
+                                       Register output, Label* success,
+                                       Label* fail, Label* slowCheck) {
+  Label* isObject = fail;
+  Label* isFunction = fail;
+  Label* isUndefined = fail;
+
+  switch (mir->jstype()) {
+    case JSTYPE_UNDEFINED:
+      isUndefined = success;
+      break;
+
+    case JSTYPE_OBJECT:
+      isObject = success;
+      break;
+
+    case JSTYPE_FUNCTION:
+      isFunction = success;
+      break;
+
+    case JSTYPE_STRING:
+    case JSTYPE_NUMBER:
+    case JSTYPE_BOOLEAN:
+    case JSTYPE_SYMBOL:
+    case JSTYPE_BIGINT:
+#ifdef ENABLE_RECORD_TUPLE
+    case JSTYPE_RECORD:
+    case JSTYPE_TUPLE:
+#endif
+    case JSTYPE_LIMIT:
+      MOZ_CRASH("Primitive type");
+  }
+
+  masm.typeOfObject(obj, output, slowCheck, isObject, isFunction, isUndefined);
+
+  auto op = mir->jsop();
+
+  Label done;
+  masm.bind(fail);
+  masm.move32(Imm32(op == JSOp::Ne || op == JSOp::StrictNe), output);
+  masm.jump(&done);
+  masm.bind(success);
+  masm.move32(Imm32(op == JSOp::Eq || op == JSOp::StrictEq), output);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitTypeOfIsNonPrimitiveV(LTypeOfIsNonPrimitiveV* lir) {
+  ValueOperand input = ToValue(lir, LTypeOfIsNonPrimitiveV::InputIndex);
+  Register output = ToRegister(lir->output());
+  Register temp = ToTempUnboxRegister(lir->temp0());
+
+  auto* mir = lir->mir();
+
+  auto* ool = new (alloc()) OutOfLineTypeOfIsNonPrimitiveV(lir);
+  addOutOfLineCode(ool, mir);
+
+  Label success, fail;
+
+  switch (mir->jstype()) {
+    case JSTYPE_UNDEFINED: {
+      ScratchTagScope tag(masm, input);
+      masm.splitTagForTest(input, tag);
+
+      masm.branchTestUndefined(Assembler::Equal, tag, &success);
+      masm.branchTestObject(Assembler::NotEqual, tag, &fail);
+      break;
+    }
+
+    case JSTYPE_OBJECT: {
+      ScratchTagScope tag(masm, input);
+      masm.splitTagForTest(input, tag);
+
+      masm.branchTestNull(Assembler::Equal, tag, &success);
+      masm.branchTestObject(Assembler::NotEqual, tag, &fail);
+      break;
+    }
+
+    case JSTYPE_FUNCTION: {
+      masm.branchTestObject(Assembler::NotEqual, input, &fail);
+      break;
+    }
+
+    case JSTYPE_STRING:
+    case JSTYPE_NUMBER:
+    case JSTYPE_BOOLEAN:
+    case JSTYPE_SYMBOL:
+    case JSTYPE_BIGINT:
+#ifdef ENABLE_RECORD_TUPLE
+    case JSTYPE_RECORD:
+    case JSTYPE_TUPLE:
+#endif
+    case JSTYPE_LIMIT:
+      MOZ_CRASH("Primitive type");
+  }
+
+  Register obj = masm.extractObject(input, temp);
+
+  emitTypeOfIsObject(mir, obj, output, &success, &fail, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitTypeOfIsNonPrimitiveO(LTypeOfIsNonPrimitiveO* lir) {
+  Register input = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  auto* mir = lir->mir();
+
+  auto* ool = new (alloc()) OutOfLineTypeOfIsNonPrimitiveO(lir);
+  addOutOfLineCode(ool, mir);
+
+  Label success, fail;
+  emitTypeOfIsObject(mir, input, output, &success, &fail, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitTypeOfIsPrimitive(LTypeOfIsPrimitive* lir) {
+  ValueOperand input = ToValue(lir, LTypeOfIsPrimitive::InputIndex);
+  Register output = ToRegister(lir->output());
+
+  auto* mir = lir->mir();
+  auto cond = JSOpToCondition(mir->jsop(), /* isSigned = */ false);
+
+  switch (mir->jstype()) {
+    case JSTYPE_STRING:
+      masm.testStringSet(cond, input, output);
+      break;
+    case JSTYPE_NUMBER:
+      masm.testNumberSet(cond, input, output);
+      break;
+    case JSTYPE_BOOLEAN:
+      masm.testBooleanSet(cond, input, output);
+      break;
+    case JSTYPE_SYMBOL:
+      masm.testSymbolSet(cond, input, output);
+      break;
+    case JSTYPE_BIGINT:
+      masm.testBigIntSet(cond, input, output);
+      break;
+
+    case JSTYPE_UNDEFINED:
+    case JSTYPE_OBJECT:
+    case JSTYPE_FUNCTION:
+#ifdef ENABLE_RECORD_TUPLE
+    case JSTYPE_RECORD:
+    case JSTYPE_TUPLE:
+#endif
+    case JSTYPE_LIMIT:
+      MOZ_CRASH("Non-primitive type");
+  }
+}
+
+void CodeGenerator::visitToAsyncIter(LToAsyncIter* lir) {
+  pushArg(ToValue(lir, LToAsyncIter::NextMethodIndex));
+  pushArg(ToRegister(lir->iterator()));
+
+  using Fn = JSObject* (*)(JSContext*, HandleObject, HandleValue);
+  callVM<Fn, js::CreateAsyncFromSyncIterator>(lir);
+}
+
+void CodeGenerator::visitToPropertyKeyCache(LToPropertyKeyCache* lir) {
+  LiveRegisterSet liveRegs = lir->safepoint()->liveRegs();
+  ValueOperand input = ToValue(lir, LToPropertyKeyCache::InputIndex);
+  ValueOperand output = ToOutValue(lir);
+
+  IonToPropertyKeyIC ic(liveRegs, input, output);
+  addIC(lir, allocateIC(ic));
+}
+
+void CodeGenerator::visitLoadElementV(LLoadElementV* load) {
+  Register elements = ToRegister(load->elements());
+  const ValueOperand out = ToOutValue(load);
+
+  if (load->index()->isConstant()) {
+    NativeObject::elementsSizeMustNotOverflow();
+    int32_t offset = ToInt32(load->index()) * sizeof(Value);
+    masm.loadValue(Address(elements, offset), out);
+  } else {
+    masm.loadValue(BaseObjectElementIndex(elements, ToRegister(load->index())),
+                   out);
+  }
+
+  Label testMagic;
+  masm.branchTestMagic(Assembler::Equal, out, &testMagic);
+  bailoutFrom(&testMagic, load->snapshot());
+}
+
+void CodeGenerator::visitLoadElementHole(LLoadElementHole* lir) {
+  Register elements = ToRegister(lir->elements());
+  Register index = ToRegister(lir->index());
+  Register initLength = ToRegister(lir->initLength());
+  const ValueOperand out = ToOutValue(lir);
+
+  const MLoadElementHole* mir = lir->mir();
+
+  // If the index is out of bounds, load |undefined|. Otherwise, load the
+  // value.
+  Label outOfBounds, done;
+  masm.spectreBoundsCheck32(index, initLength, out.scratchReg(), &outOfBounds);
+
+  masm.loadValue(BaseObjectElementIndex(elements, index), out);
+
+  // If the value wasn't a hole, we're done. Otherwise, we'll load undefined.
+  masm.branchTestMagic(Assembler::NotEqual, out, &done);
+
+  if (mir->needsNegativeIntCheck()) {
+    Label loadUndefined;
+    masm.jump(&loadUndefined);
+
+    masm.bind(&outOfBounds);
+
+    bailoutCmp32(Assembler::LessThan, index, Imm32(0), lir->snapshot());
+
+    masm.bind(&loadUndefined);
+  } else {
+    masm.bind(&outOfBounds);
+  }
+  masm.moveValue(UndefinedValue(), out);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitLoadUnboxedScalar(LLoadUnboxedScalar* lir) {
+  Register elements = ToRegister(lir->elements());
+  Register temp = ToTempRegisterOrInvalid(lir->temp0());
+  AnyRegister out = ToAnyRegister(lir->output());
+
+  const MLoadUnboxedScalar* mir = lir->mir();
+
+  Scalar::Type storageType = mir->storageType();
+
+  Label fail;
+  if (lir->index()->isConstant()) {
+    Address source =
+        ToAddress(elements, lir->index(), storageType, mir->offsetAdjustment());
+    masm.loadFromTypedArray(storageType, source, out, temp, &fail);
+  } else {
+    BaseIndex source(elements, ToRegister(lir->index()),
+                     ScaleFromScalarType(storageType), mir->offsetAdjustment());
+    masm.loadFromTypedArray(storageType, source, out, temp, &fail);
+  }
+
+  if (fail.used()) {
+    bailoutFrom(&fail, lir->snapshot());
+  }
+}
+
+void CodeGenerator::visitLoadUnboxedBigInt(LLoadUnboxedBigInt* lir) {
+  Register elements = ToRegister(lir->elements());
+  Register temp = ToRegister(lir->temp());
+  Register64 temp64 = ToRegister64(lir->temp64());
+  Register out = ToRegister(lir->output());
+
+  const MLoadUnboxedScalar* mir = lir->mir();
+
+  Scalar::Type storageType = mir->storageType();
+
+  if (lir->index()->isConstant()) {
+    Address source =
+        ToAddress(elements, lir->index(), storageType, mir->offsetAdjustment());
+    masm.load64(source, temp64);
+  } else {
+    BaseIndex source(elements, ToRegister(lir->index()),
+                     ScaleFromScalarType(storageType), mir->offsetAdjustment());
+    masm.load64(source, temp64);
+  }
+
+  emitCreateBigInt(lir, storageType, temp64, out, temp);
+}
+
+void CodeGenerator::visitLoadDataViewElement(LLoadDataViewElement* lir) {
+  Register elements = ToRegister(lir->elements());
+  const LAllocation* littleEndian = lir->littleEndian();
+  Register temp = ToTempRegisterOrInvalid(lir->temp());
+  Register64 temp64 = ToTempRegister64OrInvalid(lir->temp64());
+  AnyRegister out = ToAnyRegister(lir->output());
+
+  const MLoadDataViewElement* mir = lir->mir();
+  Scalar::Type storageType = mir->storageType();
+
+  BaseIndex source(elements, ToRegister(lir->index()), TimesOne);
+
+  bool noSwap = littleEndian->isConstant() &&
+                ToBoolean(littleEndian) == MOZ_LITTLE_ENDIAN();
+
+  // Directly load if no byte swap is needed and the platform supports unaligned
+  // accesses for the access.  (Such support is assumed for integer types.)
+  if (noSwap && (!Scalar::isFloatingType(storageType) ||
+                 MacroAssembler::SupportsFastUnalignedFPAccesses())) {
+    if (!Scalar::isBigIntType(storageType)) {
+      Label fail;
+      masm.loadFromTypedArray(storageType, source, out, temp, &fail);
+
+      if (fail.used()) {
+        bailoutFrom(&fail, lir->snapshot());
+      }
+    } else {
+      masm.load64(source, temp64);
+
+      emitCreateBigInt(lir, storageType, temp64, out.gpr(), temp);
+    }
+    return;
+  }
+
+  // Load the value into a gpr register.
+  switch (storageType) {
+    case Scalar::Int16:
+      masm.load16UnalignedSignExtend(source, out.gpr());
+      break;
+    case Scalar::Uint16:
+      masm.load16UnalignedZeroExtend(source, out.gpr());
+      break;
+    case Scalar::Int32:
+      masm.load32Unaligned(source, out.gpr());
+      break;
+    case Scalar::Uint32:
+      masm.load32Unaligned(source, out.isFloat() ? temp : out.gpr());
+      break;
+    case Scalar::Float32:
+      masm.load32Unaligned(source, temp);
+      break;
+    case Scalar::Float64:
+    case Scalar::BigInt64:
+    case Scalar::BigUint64:
+      masm.load64Unaligned(source, temp64);
+      break;
+    case Scalar::Int8:
+    case Scalar::Uint8:
+    case Scalar::Uint8Clamped:
+    default:
+      MOZ_CRASH("Invalid typed array type");
+  }
+
+  if (!noSwap) {
+    // Swap the bytes in the loaded value.
+    Label skip;
+    if (!littleEndian->isConstant()) {
+      masm.branch32(
+          MOZ_LITTLE_ENDIAN() ? Assembler::NotEqual : Assembler::Equal,
+          ToRegister(littleEndian), Imm32(0), &skip);
+    }
+
+    switch (storageType) {
+      case Scalar::Int16:
+        masm.byteSwap16SignExtend(out.gpr());
+        break;
+      case Scalar::Uint16:
+        masm.byteSwap16ZeroExtend(out.gpr());
+        break;
+      case Scalar::Int32:
+        masm.byteSwap32(out.gpr());
+        break;
+      case Scalar::Uint32:
+        masm.byteSwap32(out.isFloat() ? temp : out.gpr());
+        break;
+      case Scalar::Float32:
+        masm.byteSwap32(temp);
+        break;
+      case Scalar::Float64:
+      case Scalar::BigInt64:
+      case Scalar::BigUint64:
+        masm.byteSwap64(temp64);
+        break;
+      case Scalar::Int8:
+      case Scalar::Uint8:
+      case Scalar::Uint8Clamped:
+      default:
+        MOZ_CRASH("Invalid typed array type");
+    }
+
+    if (skip.used()) {
+      masm.bind(&skip);
+    }
+  }
+
+  // Move the value into the output register.
+  switch (storageType) {
+    case Scalar::Int16:
+    case Scalar::Uint16:
+    case Scalar::Int32:
+      break;
+    case Scalar::Uint32:
+      if (out.isFloat()) {
+        masm.convertUInt32ToDouble(temp, out.fpu());
+      } else {
+        // Bail out if the value doesn't fit into a signed int32 value. This
+        // is what allows MLoadDataViewElement to have a type() of
+        // MIRType::Int32 for UInt32 array loads.
+        bailoutTest32(Assembler::Signed, out.gpr(), out.gpr(), lir->snapshot());
+      }
+      break;
+    case Scalar::Float32:
+      masm.moveGPRToFloat32(temp, out.fpu());
+      masm.canonicalizeFloat(out.fpu());
+      break;
+    case Scalar::Float64:
+      masm.moveGPR64ToDouble(temp64, out.fpu());
+      masm.canonicalizeDouble(out.fpu());
+      break;
+    case Scalar::BigInt64:
+    case Scalar::BigUint64:
+      emitCreateBigInt(lir, storageType, temp64, out.gpr(), temp);
+      break;
+    case Scalar::Int8:
+    case Scalar::Uint8:
+    case Scalar::Uint8Clamped:
+    default:
+      MOZ_CRASH("Invalid typed array type");
+  }
+}
+
+void CodeGenerator::visitLoadTypedArrayElementHole(
+    LLoadTypedArrayElementHole* lir) {
+  Register object = ToRegister(lir->object());
+  const ValueOperand out = ToOutValue(lir);
+
+  // Load the length.
+  Register scratch = out.scratchReg();
+  Register scratch2 = ToRegister(lir->temp0());
+  Register index = ToRegister(lir->index());
+  masm.loadArrayBufferViewLengthIntPtr(object, scratch);
+
+  // Load undefined if index >= length.
+  Label outOfBounds, done;
+  masm.spectreBoundsCheckPtr(index, scratch, scratch2, &outOfBounds);
+
+  // Load the elements vector.
+  masm.loadPtr(Address(object, ArrayBufferViewObject::dataOffset()), scratch);
+
+  Scalar::Type arrayType = lir->mir()->arrayType();
+  Label fail;
+  BaseIndex source(scratch, index, ScaleFromScalarType(arrayType));
+  MacroAssembler::Uint32Mode uint32Mode =
+      lir->mir()->forceDouble() ? MacroAssembler::Uint32Mode::ForceDouble
+                                : MacroAssembler::Uint32Mode::FailOnDouble;
+  masm.loadFromTypedArray(arrayType, source, out, uint32Mode, out.scratchReg(),
+                          &fail);
+  masm.jump(&done);
+
+  masm.bind(&outOfBounds);
+  masm.moveValue(UndefinedValue(), out);
+
+  if (fail.used()) {
+    bailoutFrom(&fail, lir->snapshot());
+  }
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitLoadTypedArrayElementHoleBigInt(
+    LLoadTypedArrayElementHoleBigInt* lir) {
+  Register object = ToRegister(lir->object());
+  const ValueOperand out = ToOutValue(lir);
+
+  // On x86 there are not enough registers. In that case reuse the output's
+  // type register as temporary.
+#ifdef JS_CODEGEN_X86
+  MOZ_ASSERT(lir->temp()->isBogusTemp());
+  Register temp = out.typeReg();
+#else
+  Register temp = ToRegister(lir->temp());
+#endif
+  Register64 temp64 = ToRegister64(lir->temp64());
+
+  // Load the length.
+  Register scratch = out.scratchReg();
+  Register index = ToRegister(lir->index());
+  masm.loadArrayBufferViewLengthIntPtr(object, scratch);
+
+  // Load undefined if index >= length.
+  Label outOfBounds, done;
+  masm.spectreBoundsCheckPtr(index, scratch, temp, &outOfBounds);
+
+  // Load the elements vector.
+  masm.loadPtr(Address(object, ArrayBufferViewObject::dataOffset()), scratch);
+
+  Scalar::Type arrayType = lir->mir()->arrayType();
+  BaseIndex source(scratch, index, ScaleFromScalarType(arrayType));
+  masm.load64(source, temp64);
+
+  Register bigInt = out.scratchReg();
+  emitCreateBigInt(lir, arrayType, temp64, bigInt, temp);
+
+  masm.tagValue(JSVAL_TYPE_BIGINT, bigInt, out);
+  masm.jump(&done);
+
+  masm.bind(&outOfBounds);
+  masm.moveValue(UndefinedValue(), out);
+
+  masm.bind(&done);
+}
+
+template <SwitchTableType tableType>
+class OutOfLineSwitch : public OutOfLineCodeBase<CodeGenerator> {
+  using LabelsVector = Vector<Label, 0, JitAllocPolicy>;
+  using CodeLabelsVector = Vector<CodeLabel, 0, JitAllocPolicy>;
+  LabelsVector labels_;
+  CodeLabelsVector codeLabels_;
+  CodeLabel start_;
+  bool isOutOfLine_;
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineSwitch(this);
+  }
+
+ public:
+  explicit OutOfLineSwitch(TempAllocator& alloc)
+      : labels_(alloc), codeLabels_(alloc), isOutOfLine_(false) {}
+
+  CodeLabel* start() { return &start_; }
+
+  CodeLabelsVector& codeLabels() { return codeLabels_; }
+  LabelsVector& labels() { return labels_; }
+
+  void jumpToCodeEntries(MacroAssembler& masm, Register index, Register temp) {
+    Register base;
+    if (tableType == SwitchTableType::Inline) {
+#if defined(JS_CODEGEN_ARM)
+      base = ::js::jit::pc;
+#else
+      MOZ_CRASH("NYI: SwitchTableType::Inline");
+#endif
+    } else {
+#if defined(JS_CODEGEN_ARM)
+      MOZ_CRASH("NYI: SwitchTableType::OutOfLine");
+#else
+      masm.mov(start(), temp);
+      base = temp;
+#endif
+    }
+    BaseIndex jumpTarget(base, index, ScalePointer);
+    masm.branchToComputedAddress(jumpTarget);
+  }
+
+  // Register an entry in the switch table.
+  void addTableEntry(MacroAssembler& masm) {
+    if ((!isOutOfLine_ && tableType == SwitchTableType::Inline) ||
+        (isOutOfLine_ && tableType == SwitchTableType::OutOfLine)) {
+      CodeLabel cl;
+      masm.writeCodePointer(&cl);
+      masm.propagateOOM(codeLabels_.append(std::move(cl)));
+    }
+  }
+  // Register the code, to which the table will jump to.
+  void addCodeEntry(MacroAssembler& masm) {
+    Label entry;
+    masm.bind(&entry);
+    masm.propagateOOM(labels_.append(std::move(entry)));
+  }
+
+  void setOutOfLine() { isOutOfLine_ = true; }
+};
+
+template <SwitchTableType tableType>
+void CodeGenerator::visitOutOfLineSwitch(
+    OutOfLineSwitch<tableType>* jumpTable) {
+  jumpTable->setOutOfLine();
+  auto& labels = jumpTable->labels();
+
+  if (tableType == SwitchTableType::OutOfLine) {
+#if defined(JS_CODEGEN_ARM)
+    MOZ_CRASH("NYI: SwitchTableType::OutOfLine");
+#elif defined(JS_CODEGEN_NONE)
+    MOZ_CRASH();
+#else
+
+#  if defined(JS_CODEGEN_ARM64)
+    AutoForbidPoolsAndNops afp(
+        &masm,
+        (labels.length() + 1) * (sizeof(void*) / vixl::kInstructionSize));
+#  endif
+
+    masm.haltingAlign(sizeof(void*));
+
+    // Bind the address of the jump table and reserve the space for code
+    // pointers to jump in the newly generated code.
+    masm.bind(jumpTable->start());
+    masm.addCodeLabel(*jumpTable->start());
+    for (size_t i = 0, e = labels.length(); i < e; i++) {
+      jumpTable->addTableEntry(masm);
+    }
+#endif
+  }
+
+  // Register all reserved pointers of the jump table to target labels. The
+  // entries of the jump table need to be absolute addresses and thus must be
+  // patched after codegen is finished.
+  auto& codeLabels = jumpTable->codeLabels();
+  for (size_t i = 0, e = codeLabels.length(); i < e; i++) {
+    auto& cl = codeLabels[i];
+    cl.target()->bind(labels[i].offset());
+    masm.addCodeLabel(cl);
+  }
+}
+
+template void CodeGenerator::visitOutOfLineSwitch(
+    OutOfLineSwitch<SwitchTableType::Inline>* jumpTable);
+template void CodeGenerator::visitOutOfLineSwitch(
+    OutOfLineSwitch<SwitchTableType::OutOfLine>* jumpTable);
+
+template <typename T>
+static inline void StoreToTypedArray(MacroAssembler& masm,
+                                     Scalar::Type writeType,
+                                     const LAllocation* value, const T& dest) {
+  if (writeType == Scalar::Float32 || writeType == Scalar::Float64) {
+    masm.storeToTypedFloatArray(writeType, ToFloatRegister(value), dest);
+  } else {
+    if (value->isConstant()) {
+      masm.storeToTypedIntArray(writeType, Imm32(ToInt32(value)), dest);
+    } else {
+      masm.storeToTypedIntArray(writeType, ToRegister(value), dest);
+    }
+  }
+}
+
+void CodeGenerator::visitStoreUnboxedScalar(LStoreUnboxedScalar* lir) {
+  Register elements = ToRegister(lir->elements());
+  const LAllocation* value = lir->value();
+
+  const MStoreUnboxedScalar* mir = lir->mir();
+
+  Scalar::Type writeType = mir->writeType();
+
+  if (lir->index()->isConstant()) {
+    Address dest = ToAddress(elements, lir->index(), writeType);
+    StoreToTypedArray(masm, writeType, value, dest);
+  } else {
+    BaseIndex dest(elements, ToRegister(lir->index()),
+                   ScaleFromScalarType(writeType));
+    StoreToTypedArray(masm, writeType, value, dest);
+  }
+}
+
+void CodeGenerator::visitStoreUnboxedBigInt(LStoreUnboxedBigInt* lir) {
+  Register elements = ToRegister(lir->elements());
+  Register value = ToRegister(lir->value());
+  Register64 temp = ToRegister64(lir->temp());
+
+  Scalar::Type writeType = lir->mir()->writeType();
+
+  masm.loadBigInt64(value, temp);
+
+  if (lir->index()->isConstant()) {
+    Address dest = ToAddress(elements, lir->index(), writeType);
+    masm.storeToTypedBigIntArray(writeType, temp, dest);
+  } else {
+    BaseIndex dest(elements, ToRegister(lir->index()),
+                   ScaleFromScalarType(writeType));
+    masm.storeToTypedBigIntArray(writeType, temp, dest);
+  }
+}
+
+void CodeGenerator::visitStoreDataViewElement(LStoreDataViewElement* lir) {
+  Register elements = ToRegister(lir->elements());
+  const LAllocation* value = lir->value();
+  const LAllocation* littleEndian = lir->littleEndian();
+  Register temp = ToTempRegisterOrInvalid(lir->temp());
+  Register64 temp64 = ToTempRegister64OrInvalid(lir->temp64());
+
+  const MStoreDataViewElement* mir = lir->mir();
+  Scalar::Type writeType = mir->writeType();
+
+  BaseIndex dest(elements, ToRegister(lir->index()), TimesOne);
+
+  bool noSwap = littleEndian->isConstant() &&
+                ToBoolean(littleEndian) == MOZ_LITTLE_ENDIAN();
+
+  // Directly store if no byte swap is needed and the platform supports
+  // unaligned accesses for the access.  (Such support is assumed for integer
+  // types.)
+  if (noSwap && (!Scalar::isFloatingType(writeType) ||
+                 MacroAssembler::SupportsFastUnalignedFPAccesses())) {
+    if (!Scalar::isBigIntType(writeType)) {
+      StoreToTypedArray(masm, writeType, value, dest);
+    } else {
+      masm.loadBigInt64(ToRegister(value), temp64);
+      masm.storeToTypedBigIntArray(writeType, temp64, dest);
+    }
+    return;
+  }
+
+  // Load the value into a gpr register.
+  switch (writeType) {
+    case Scalar::Int16:
+    case Scalar::Uint16:
+    case Scalar::Int32:
+    case Scalar::Uint32:
+      if (value->isConstant()) {
+        masm.move32(Imm32(ToInt32(value)), temp);
+      } else {
+        masm.move32(ToRegister(value), temp);
+      }
+      break;
+    case Scalar::Float32: {
+      FloatRegister fvalue = ToFloatRegister(value);
+      masm.canonicalizeFloatIfDeterministic(fvalue);
+      masm.moveFloat32ToGPR(fvalue, temp);
+      break;
+    }
+    case Scalar::Float64: {
+      FloatRegister fvalue = ToFloatRegister(value);
+      masm.canonicalizeDoubleIfDeterministic(fvalue);
+      masm.moveDoubleToGPR64(fvalue, temp64);
+      break;
+    }
+    case Scalar::BigInt64:
+    case Scalar::BigUint64:
+      masm.loadBigInt64(ToRegister(value), temp64);
+      break;
+    case Scalar::Int8:
+    case Scalar::Uint8:
+    case Scalar::Uint8Clamped:
+    default:
+      MOZ_CRASH("Invalid typed array type");
+  }
+
+  if (!noSwap) {
+    // Swap the bytes in the loaded value.
+    Label skip;
+    if (!littleEndian->isConstant()) {
+      masm.branch32(
+          MOZ_LITTLE_ENDIAN() ? Assembler::NotEqual : Assembler::Equal,
+          ToRegister(littleEndian), Imm32(0), &skip);
+    }
+
+    switch (writeType) {
+      case Scalar::Int16:
+        masm.byteSwap16SignExtend(temp);
+        break;
+      case Scalar::Uint16:
+        masm.byteSwap16ZeroExtend(temp);
+        break;
+      case Scalar::Int32:
+      case Scalar::Uint32:
+      case Scalar::Float32:
+        masm.byteSwap32(temp);
+        break;
+      case Scalar::Float64:
+      case Scalar::BigInt64:
+      case Scalar::BigUint64:
+        masm.byteSwap64(temp64);
+        break;
+      case Scalar::Int8:
+      case Scalar::Uint8:
+      case Scalar::Uint8Clamped:
+      default:
+        MOZ_CRASH("Invalid typed array type");
+    }
+
+    if (skip.used()) {
+      masm.bind(&skip);
+    }
+  }
+
+  // Store the value into the destination.
+  switch (writeType) {
+    case Scalar::Int16:
+    case Scalar::Uint16:
+      masm.store16Unaligned(temp, dest);
+      break;
+    case Scalar::Int32:
+    case Scalar::Uint32:
+    case Scalar::Float32:
+      masm.store32Unaligned(temp, dest);
+      break;
+    case Scalar::Float64:
+    case Scalar::BigInt64:
+    case Scalar::BigUint64:
+      masm.store64Unaligned(temp64, dest);
+      break;
+    case Scalar::Int8:
+    case Scalar::Uint8:
+    case Scalar::Uint8Clamped:
+    default:
+      MOZ_CRASH("Invalid typed array type");
+  }
+}
+
+void CodeGenerator::visitStoreTypedArrayElementHole(
+    LStoreTypedArrayElementHole* lir) {
+  Register elements = ToRegister(lir->elements());
+  const LAllocation* value = lir->value();
+
+  Scalar::Type arrayType = lir->mir()->arrayType();
+
+  Register index = ToRegister(lir->index());
+  const LAllocation* length = lir->length();
+  Register spectreTemp = ToTempRegisterOrInvalid(lir->temp0());
+
+  Label skip;
+  if (length->isRegister()) {
+    masm.spectreBoundsCheckPtr(index, ToRegister(length), spectreTemp, &skip);
+  } else {
+    masm.spectreBoundsCheckPtr(index, ToAddress(length), spectreTemp, &skip);
+  }
+
+  BaseIndex dest(elements, index, ScaleFromScalarType(arrayType));
+  StoreToTypedArray(masm, arrayType, value, dest);
+
+  masm.bind(&skip);
+}
+
+void CodeGenerator::visitStoreTypedArrayElementHoleBigInt(
+    LStoreTypedArrayElementHoleBigInt* lir) {
+  Register elements = ToRegister(lir->elements());
+  Register value = ToRegister(lir->value());
+  Register64 temp = ToRegister64(lir->temp());
+
+  Scalar::Type arrayType = lir->mir()->arrayType();
+
+  Register index = ToRegister(lir->index());
+  const LAllocation* length = lir->length();
+  Register spectreTemp = temp.scratchReg();
+
+  Label skip;
+  if (length->isRegister()) {
+    masm.spectreBoundsCheckPtr(index, ToRegister(length), spectreTemp, &skip);
+  } else {
+    masm.spectreBoundsCheckPtr(index, ToAddress(length), spectreTemp, &skip);
+  }
+
+  masm.loadBigInt64(value, temp);
+
+  BaseIndex dest(elements, index, ScaleFromScalarType(arrayType));
+  masm.storeToTypedBigIntArray(arrayType, temp, dest);
+
+  masm.bind(&skip);
+}
+
+void CodeGenerator::visitAtomicIsLockFree(LAtomicIsLockFree* lir) {
+  Register value = ToRegister(lir->value());
+  Register output = ToRegister(lir->output());
+
+  masm.atomicIsLockFreeJS(value, output);
+}
+
+void CodeGenerator::visitClampIToUint8(LClampIToUint8* lir) {
+  Register output = ToRegister(lir->output());
+  MOZ_ASSERT(output == ToRegister(lir->input()));
+  masm.clampIntToUint8(output);
+}
+
+void CodeGenerator::visitClampDToUint8(LClampDToUint8* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+  Register output = ToRegister(lir->output());
+  masm.clampDoubleToUint8(input, output);
+}
+
+void CodeGenerator::visitClampVToUint8(LClampVToUint8* lir) {
+  ValueOperand operand = ToValue(lir, LClampVToUint8::InputIndex);
+  FloatRegister tempFloat = ToFloatRegister(lir->temp0());
+  Register output = ToRegister(lir->output());
+
+  using Fn = bool (*)(JSContext*, JSString*, double*);
+  OutOfLineCode* oolString = oolCallVM<Fn, StringToNumber>(
+      lir, ArgList(output), StoreFloatRegisterTo(tempFloat));
+  Label* stringEntry = oolString->entry();
+  Label* stringRejoin = oolString->rejoin();
+
+  Label fails;
+  masm.clampValueToUint8(operand, stringEntry, stringRejoin, output, tempFloat,
+                         output, &fails);
+
+  bailoutFrom(&fails, lir->snapshot());
+}
+
+void CodeGenerator::visitInCache(LInCache* ins) {
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+
+  ConstantOrRegister key =
+      toConstantOrRegister(ins, LInCache::LhsIndex, ins->mir()->key()->type());
+  Register object = ToRegister(ins->rhs());
+  Register output = ToRegister(ins->output());
+  Register temp = ToRegister(ins->temp0());
+
+  IonInIC cache(liveRegs, key, object, output, temp);
+  addIC(ins, allocateIC(cache));
+}
+
+void CodeGenerator::visitInArray(LInArray* lir) {
+  const MInArray* mir = lir->mir();
+  Register elements = ToRegister(lir->elements());
+  Register initLength = ToRegister(lir->initLength());
+  Register output = ToRegister(lir->output());
+
+  Label falseBranch, done, trueBranch;
+
+  if (lir->index()->isConstant()) {
+    int32_t index = ToInt32(lir->index());
+
+    if (index < 0) {
+      MOZ_ASSERT(mir->needsNegativeIntCheck());
+      bailout(lir->snapshot());
+      return;
+    }
+
+    masm.branch32(Assembler::BelowOrEqual, initLength, Imm32(index),
+                  &falseBranch);
+
+    NativeObject::elementsSizeMustNotOverflow();
+    Address address = Address(elements, index * sizeof(Value));
+    masm.branchTestMagic(Assembler::Equal, address, &falseBranch);
+  } else {
+    Register index = ToRegister(lir->index());
+
+    Label negativeIntCheck;
+    Label* failedInitLength = &falseBranch;
+    if (mir->needsNegativeIntCheck()) {
+      failedInitLength = &negativeIntCheck;
+    }
+
+    masm.branch32(Assembler::BelowOrEqual, initLength, index, failedInitLength);
+
+    BaseObjectElementIndex address(elements, index);
+    masm.branchTestMagic(Assembler::Equal, address, &falseBranch);
+
+    if (mir->needsNegativeIntCheck()) {
+      masm.jump(&trueBranch);
+      masm.bind(&negativeIntCheck);
+
+      bailoutCmp32(Assembler::LessThan, index, Imm32(0), lir->snapshot());
+
+      masm.jump(&falseBranch);
+    }
+  }
+
+  masm.bind(&trueBranch);
+  masm.move32(Imm32(1), output);
+  masm.jump(&done);
+
+  masm.bind(&falseBranch);
+  masm.move32(Imm32(0), output);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGuardElementNotHole(LGuardElementNotHole* lir) {
+  Register elements = ToRegister(lir->elements());
+  const LAllocation* index = lir->index();
+
+  Label testMagic;
+  if (index->isConstant()) {
+    Address address(elements, ToInt32(index) * sizeof(js::Value));
+    masm.branchTestMagic(Assembler::Equal, address, &testMagic);
+  } else {
+    BaseObjectElementIndex address(elements, ToRegister(index));
+    masm.branchTestMagic(Assembler::Equal, address, &testMagic);
+  }
+  bailoutFrom(&testMagic, lir->snapshot());
+}
+
+void CodeGenerator::visitInstanceOfO(LInstanceOfO* ins) {
+  Register protoReg = ToRegister(ins->rhs());
+  emitInstanceOf(ins, protoReg);
+}
+
+void CodeGenerator::visitInstanceOfV(LInstanceOfV* ins) {
+  Register protoReg = ToRegister(ins->rhs());
+  emitInstanceOf(ins, protoReg);
+}
+
+void CodeGenerator::emitInstanceOf(LInstruction* ins, Register protoReg) {
+  // This path implements fun_hasInstance when the function's prototype is
+  // known to be the object in protoReg
+
+  Label done;
+  Register output = ToRegister(ins->getDef(0));
+
+  // If the lhs is a primitive, the result is false.
+  Register objReg;
+  if (ins->isInstanceOfV()) {
+    Label isObject;
+    ValueOperand lhsValue = ToValue(ins, LInstanceOfV::LhsIndex);
+    masm.branchTestObject(Assembler::Equal, lhsValue, &isObject);
+    masm.mov(ImmWord(0), output);
+    masm.jump(&done);
+    masm.bind(&isObject);
+    objReg = masm.extractObject(lhsValue, output);
+  } else {
+    objReg = ToRegister(ins->toInstanceOfO()->lhs());
+  }
+
+  // Crawl the lhs's prototype chain in a loop to search for prototypeObject.
+  // This follows the main loop of js::IsPrototypeOf, though additionally breaks
+  // out of the loop on Proxy::LazyProto.
+
+  // Load the lhs's prototype.
+  masm.loadObjProto(objReg, output);
+
+  Label testLazy;
+  {
+    Label loopPrototypeChain;
+    masm.bind(&loopPrototypeChain);
+
+    // Test for the target prototype object.
+    Label notPrototypeObject;
+    masm.branchPtr(Assembler::NotEqual, output, protoReg, &notPrototypeObject);
+    masm.mov(ImmWord(1), output);
+    masm.jump(&done);
+    masm.bind(&notPrototypeObject);
+
+    MOZ_ASSERT(uintptr_t(TaggedProto::LazyProto) == 1);
+
+    // Test for nullptr or Proxy::LazyProto
+    masm.branchPtr(Assembler::BelowOrEqual, output, ImmWord(1), &testLazy);
+
+    // Load the current object's prototype.
+    masm.loadObjProto(output, output);
+
+    masm.jump(&loopPrototypeChain);
+  }
+
+  // Make a VM call if an object with a lazy proto was found on the prototype
+  // chain. This currently occurs only for cross compartment wrappers, which
+  // we do not expect to be compared with non-wrapper functions from this
+  // compartment. Otherwise, we stopped on a nullptr prototype and the output
+  // register is already correct.
+
+  using Fn = bool (*)(JSContext*, HandleObject, JSObject*, bool*);
+  auto* ool = oolCallVM<Fn, IsPrototypeOf>(ins, ArgList(protoReg, objReg),
+                                           StoreRegisterTo(output));
+
+  // Regenerate the original lhs object for the VM call.
+  Label regenerate, *lazyEntry;
+  if (objReg != output) {
+    lazyEntry = ool->entry();
+  } else {
+    masm.bind(&regenerate);
+    lazyEntry = &regenerate;
+    if (ins->isInstanceOfV()) {
+      ValueOperand lhsValue = ToValue(ins, LInstanceOfV::LhsIndex);
+      objReg = masm.extractObject(lhsValue, output);
+    } else {
+      objReg = ToRegister(ins->toInstanceOfO()->lhs());
+    }
+    MOZ_ASSERT(objReg == output);
+    masm.jump(ool->entry());
+  }
+
+  masm.bind(&testLazy);
+  masm.branchPtr(Assembler::Equal, output, ImmWord(1), lazyEntry);
+
+  masm.bind(&done);
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitInstanceOfCache(LInstanceOfCache* ins) {
+  // The Lowering ensures that RHS is an object, and that LHS is a value.
+  LiveRegisterSet liveRegs = ins->safepoint()->liveRegs();
+  TypedOrValueRegister lhs =
+      TypedOrValueRegister(ToValue(ins, LInstanceOfCache::LHS));
+  Register rhs = ToRegister(ins->rhs());
+  Register output = ToRegister(ins->output());
+
+  IonInstanceOfIC ic(liveRegs, lhs, rhs, output);
+  addIC(ins, allocateIC(ic));
+}
+
+void CodeGenerator::visitGetDOMProperty(LGetDOMProperty* ins) {
+  const Register JSContextReg = ToRegister(ins->getJSContextReg());
+  const Register ObjectReg = ToRegister(ins->getObjectReg());
+  const Register PrivateReg = ToRegister(ins->getPrivReg());
+  const Register ValueReg = ToRegister(ins->getValueReg());
+
+  Label haveValue;
+  if (ins->mir()->valueMayBeInSlot()) {
+    size_t slot = ins->mir()->domMemberSlotIndex();
+    // It's a bit annoying to redo these slot calculations, which duplcate
+    // LSlots and a few other things like that, but I'm not sure there's a
+    // way to reuse those here.
+    //
+    // If this ever gets fixed to work with proxies (by not assuming that
+    // reserved slot indices, which is what domMemberSlotIndex() returns,
+    // match fixed slot indices), we can reenable MGetDOMProperty for
+    // proxies in IonBuilder.
+    if (slot < NativeObject::MAX_FIXED_SLOTS) {
+      masm.loadValue(Address(ObjectReg, NativeObject::getFixedSlotOffset(slot)),
+                     JSReturnOperand);
+    } else {
+      // It's a dynamic slot.
+      slot -= NativeObject::MAX_FIXED_SLOTS;
+      // Use PrivateReg as a scratch register for the slots pointer.
+      masm.loadPtr(Address(ObjectReg, NativeObject::offsetOfSlots()),
+                   PrivateReg);
+      masm.loadValue(Address(PrivateReg, slot * sizeof(js::Value)),
+                     JSReturnOperand);
+    }
+    masm.branchTestUndefined(Assembler::NotEqual, JSReturnOperand, &haveValue);
+  }
+
+  DebugOnly<uint32_t> initialStack = masm.framePushed();
+
+  masm.checkStackAlignment();
+
+  // Make space for the outparam.  Pre-initialize it to UndefinedValue so we
+  // can trace it at GC time.
+  masm.Push(UndefinedValue());
+  // We pass the pointer to our out param as an instance of
+  // JSJitGetterCallArgs, since on the binary level it's the same thing.
+  static_assert(sizeof(JSJitGetterCallArgs) == sizeof(Value*));
+  masm.moveStackPtrTo(ValueReg);
+
+  masm.Push(ObjectReg);
+
+  LoadDOMPrivate(masm, ObjectReg, PrivateReg, ins->mir()->objectKind());
+
+  // Rooting will happen at GC time.
+  masm.moveStackPtrTo(ObjectReg);
+
+  Realm* getterRealm = ins->mir()->getterRealm();
+  if (gen->realm->realmPtr() != getterRealm) {
+    // We use JSContextReg as scratch register here.
+    masm.switchToRealm(getterRealm, JSContextReg);
+  }
+
+  uint32_t safepointOffset = masm.buildFakeExitFrame(JSContextReg);
+  masm.loadJSContext(JSContextReg);
+  masm.enterFakeExitFrame(JSContextReg, JSContextReg,
+                          ExitFrameType::IonDOMGetter);
+
+  markSafepointAt(safepointOffset, ins);
+
+  masm.setupAlignedABICall();
+  masm.loadJSContext(JSContextReg);
+  masm.passABIArg(JSContextReg);
+  masm.passABIArg(ObjectReg);
+  masm.passABIArg(PrivateReg);
+  masm.passABIArg(ValueReg);
+  ensureOsiSpace();
+  masm.callWithABI(DynamicFunction<JSJitGetterOp>(ins->mir()->fun()),
+                   MoveOp::GENERAL,
+                   CheckUnsafeCallWithABI::DontCheckHasExitFrame);
+
+  if (ins->mir()->isInfallible()) {
+    masm.loadValue(Address(masm.getStackPointer(),
+                           IonDOMExitFrameLayout::offsetOfResult()),
+                   JSReturnOperand);
+  } else {
+    masm.branchIfFalseBool(ReturnReg, masm.exceptionLabel());
+
+    masm.loadValue(Address(masm.getStackPointer(),
+                           IonDOMExitFrameLayout::offsetOfResult()),
+                   JSReturnOperand);
+  }
+
+  // Switch back to the current realm if needed. Note: if the getter threw an
+  // exception, the exception handler will do this.
+  if (gen->realm->realmPtr() != getterRealm) {
+    static_assert(!JSReturnOperand.aliases(ReturnReg),
+                  "Clobbering ReturnReg should not affect the return value");
+    masm.switchToRealm(gen->realm->realmPtr(), ReturnReg);
+  }
+
+  // Until C++ code is instrumented against Spectre, prevent speculative
+  // execution from returning any private data.
+  if (JitOptions.spectreJitToCxxCalls && ins->mir()->hasLiveDefUses()) {
+    masm.speculationBarrier();
+  }
+
+  masm.adjustStack(IonDOMExitFrameLayout::Size());
+
+  masm.bind(&haveValue);
+
+  MOZ_ASSERT(masm.framePushed() == initialStack);
+}
+
+void CodeGenerator::visitGetDOMMemberV(LGetDOMMemberV* ins) {
+  // It's simpler to duplicate visitLoadFixedSlotV here than it is to try to
+  // use an LLoadFixedSlotV or some subclass of it for this case: that would
+  // require us to have MGetDOMMember inherit from MLoadFixedSlot, and then
+  // we'd have to duplicate a bunch of stuff we now get for free from
+  // MGetDOMProperty.
+  //
+  // If this ever gets fixed to work with proxies (by not assuming that
+  // reserved slot indices, which is what domMemberSlotIndex() returns,
+  // match fixed slot indices), we can reenable MGetDOMMember for
+  // proxies in IonBuilder.
+  Register object = ToRegister(ins->object());
+  size_t slot = ins->mir()->domMemberSlotIndex();
+  ValueOperand result = ToOutValue(ins);
+
+  masm.loadValue(Address(object, NativeObject::getFixedSlotOffset(slot)),
+                 result);
+}
+
+void CodeGenerator::visitGetDOMMemberT(LGetDOMMemberT* ins) {
+  // It's simpler to duplicate visitLoadFixedSlotT here than it is to try to
+  // use an LLoadFixedSlotT or some subclass of it for this case: that would
+  // require us to have MGetDOMMember inherit from MLoadFixedSlot, and then
+  // we'd have to duplicate a bunch of stuff we now get for free from
+  // MGetDOMProperty.
+  //
+  // If this ever gets fixed to work with proxies (by not assuming that
+  // reserved slot indices, which is what domMemberSlotIndex() returns,
+  // match fixed slot indices), we can reenable MGetDOMMember for
+  // proxies in IonBuilder.
+  Register object = ToRegister(ins->object());
+  size_t slot = ins->mir()->domMemberSlotIndex();
+  AnyRegister result = ToAnyRegister(ins->getDef(0));
+  MIRType type = ins->mir()->type();
+
+  masm.loadUnboxedValue(Address(object, NativeObject::getFixedSlotOffset(slot)),
+                        type, result);
+}
+
+void CodeGenerator::visitSetDOMProperty(LSetDOMProperty* ins) {
+  const Register JSContextReg = ToRegister(ins->getJSContextReg());
+  const Register ObjectReg = ToRegister(ins->getObjectReg());
+  const Register PrivateReg = ToRegister(ins->getPrivReg());
+  const Register ValueReg = ToRegister(ins->getValueReg());
+
+  DebugOnly<uint32_t> initialStack = masm.framePushed();
+
+  masm.checkStackAlignment();
+
+  // Push the argument. Rooting will happen at GC time.
+  ValueOperand argVal = ToValue(ins, LSetDOMProperty::Value);
+  masm.Push(argVal);
+  // We pass the pointer to our out param as an instance of
+  // JSJitGetterCallArgs, since on the binary level it's the same thing.
+  static_assert(sizeof(JSJitSetterCallArgs) == sizeof(Value*));
+  masm.moveStackPtrTo(ValueReg);
+
+  masm.Push(ObjectReg);
+
+  LoadDOMPrivate(masm, ObjectReg, PrivateReg, ins->mir()->objectKind());
+
+  // Rooting will happen at GC time.
+  masm.moveStackPtrTo(ObjectReg);
+
+  Realm* setterRealm = ins->mir()->setterRealm();
+  if (gen->realm->realmPtr() != setterRealm) {
+    // We use JSContextReg as scratch register here.
+    masm.switchToRealm(setterRealm, JSContextReg);
+  }
+
+  uint32_t safepointOffset = masm.buildFakeExitFrame(JSContextReg);
+  masm.loadJSContext(JSContextReg);
+  masm.enterFakeExitFrame(JSContextReg, JSContextReg,
+                          ExitFrameType::IonDOMSetter);
+
+  markSafepointAt(safepointOffset, ins);
+
+  masm.setupAlignedABICall();
+  masm.loadJSContext(JSContextReg);
+  masm.passABIArg(JSContextReg);
+  masm.passABIArg(ObjectReg);
+  masm.passABIArg(PrivateReg);
+  masm.passABIArg(ValueReg);
+  ensureOsiSpace();
+  masm.callWithABI(DynamicFunction<JSJitSetterOp>(ins->mir()->fun()),
+                   MoveOp::GENERAL,
+                   CheckUnsafeCallWithABI::DontCheckHasExitFrame);
+
+  masm.branchIfFalseBool(ReturnReg, masm.exceptionLabel());
+
+  // Switch back to the current realm if needed. Note: if the setter threw an
+  // exception, the exception handler will do this.
+  if (gen->realm->realmPtr() != setterRealm) {
+    masm.switchToRealm(gen->realm->realmPtr(), ReturnReg);
+  }
+
+  masm.adjustStack(IonDOMExitFrameLayout::Size());
+
+  MOZ_ASSERT(masm.framePushed() == initialStack);
+}
+
+void CodeGenerator::visitLoadDOMExpandoValue(LLoadDOMExpandoValue* ins) {
+  Register proxy = ToRegister(ins->proxy());
+  ValueOperand out = ToOutValue(ins);
+
+  masm.loadPtr(Address(proxy, ProxyObject::offsetOfReservedSlots()),
+               out.scratchReg());
+  masm.loadValue(Address(out.scratchReg(),
+                         js::detail::ProxyReservedSlots::offsetOfPrivateSlot()),
+                 out);
+}
+
+void CodeGenerator::visitLoadDOMExpandoValueGuardGeneration(
+    LLoadDOMExpandoValueGuardGeneration* ins) {
+  Register proxy = ToRegister(ins->proxy());
+  ValueOperand out = ToOutValue(ins);
+
+  Label bail;
+  masm.loadDOMExpandoValueGuardGeneration(proxy, out,
+                                          ins->mir()->expandoAndGeneration(),
+                                          ins->mir()->generation(), &bail);
+  bailoutFrom(&bail, ins->snapshot());
+}
+
+void CodeGenerator::visitLoadDOMExpandoValueIgnoreGeneration(
+    LLoadDOMExpandoValueIgnoreGeneration* ins) {
+  Register proxy = ToRegister(ins->proxy());
+  ValueOperand out = ToOutValue(ins);
+
+  masm.loadPtr(Address(proxy, ProxyObject::offsetOfReservedSlots()),
+               out.scratchReg());
+
+  // Load the ExpandoAndGeneration* from the PrivateValue.
+  masm.loadPrivate(
+      Address(out.scratchReg(),
+              js::detail::ProxyReservedSlots::offsetOfPrivateSlot()),
+      out.scratchReg());
+
+  // Load expandoAndGeneration->expando into the output Value register.
+  masm.loadValue(
+      Address(out.scratchReg(), ExpandoAndGeneration::offsetOfExpando()), out);
+}
+
+void CodeGenerator::visitGuardDOMExpandoMissingOrGuardShape(
+    LGuardDOMExpandoMissingOrGuardShape* ins) {
+  Register temp = ToRegister(ins->temp0());
+  ValueOperand input =
+      ToValue(ins, LGuardDOMExpandoMissingOrGuardShape::InputIndex);
+
+  Label done;
+  masm.branchTestUndefined(Assembler::Equal, input, &done);
+
+  masm.debugAssertIsObject(input);
+  masm.unboxObject(input, temp);
+  // The expando object is not used in this case, so we don't need Spectre
+  // mitigations.
+  Label bail;
+  masm.branchTestObjShapeNoSpectreMitigations(Assembler::NotEqual, temp,
+                                              ins->mir()->shape(), &bail);
+  bailoutFrom(&bail, ins->snapshot());
+
+  masm.bind(&done);
+}
+
+class OutOfLineIsCallable : public OutOfLineCodeBase<CodeGenerator> {
+  Register object_;
+  Register output_;
+
+ public:
+  OutOfLineIsCallable(Register object, Register output)
+      : object_(object), output_(output) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineIsCallable(this);
+  }
+  Register object() const { return object_; }
+  Register output() const { return output_; }
+};
+
+void CodeGenerator::visitIsCallableO(LIsCallableO* ins) {
+  Register object = ToRegister(ins->object());
+  Register output = ToRegister(ins->output());
+
+  OutOfLineIsCallable* ool = new (alloc()) OutOfLineIsCallable(object, output);
+  addOutOfLineCode(ool, ins->mir());
+
+  masm.isCallable(object, output, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitIsCallableV(LIsCallableV* ins) {
+  ValueOperand val = ToValue(ins, LIsCallableV::ObjectIndex);
+  Register output = ToRegister(ins->output());
+  Register temp = ToRegister(ins->temp0());
+
+  Label notObject;
+  masm.fallibleUnboxObject(val, temp, &notObject);
+
+  OutOfLineIsCallable* ool = new (alloc()) OutOfLineIsCallable(temp, output);
+  addOutOfLineCode(ool, ins->mir());
+
+  masm.isCallable(temp, output, ool->entry());
+  masm.jump(ool->rejoin());
+
+  masm.bind(&notObject);
+  masm.move32(Imm32(0), output);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineIsCallable(OutOfLineIsCallable* ool) {
+  Register object = ool->object();
+  Register output = ool->output();
+
+  saveVolatile(output);
+  using Fn = bool (*)(JSObject* obj);
+  masm.setupAlignedABICall();
+  masm.passABIArg(object);
+  masm.callWithABI<Fn, ObjectIsCallable>();
+  masm.storeCallBoolResult(output);
+  restoreVolatile(output);
+  masm.jump(ool->rejoin());
+}
+
+class OutOfLineIsConstructor : public OutOfLineCodeBase<CodeGenerator> {
+  LIsConstructor* ins_;
+
+ public:
+  explicit OutOfLineIsConstructor(LIsConstructor* ins) : ins_(ins) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineIsConstructor(this);
+  }
+  LIsConstructor* ins() const { return ins_; }
+};
+
+void CodeGenerator::visitIsConstructor(LIsConstructor* ins) {
+  Register object = ToRegister(ins->object());
+  Register output = ToRegister(ins->output());
+
+  OutOfLineIsConstructor* ool = new (alloc()) OutOfLineIsConstructor(ins);
+  addOutOfLineCode(ool, ins->mir());
+
+  masm.isConstructor(object, output, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineIsConstructor(OutOfLineIsConstructor* ool) {
+  LIsConstructor* ins = ool->ins();
+  Register object = ToRegister(ins->object());
+  Register output = ToRegister(ins->output());
+
+  saveVolatile(output);
+  using Fn = bool (*)(JSObject* obj);
+  masm.setupAlignedABICall();
+  masm.passABIArg(object);
+  masm.callWithABI<Fn, ObjectIsConstructor>();
+  masm.storeCallBoolResult(output);
+  restoreVolatile(output);
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitIsCrossRealmArrayConstructor(
+    LIsCrossRealmArrayConstructor* ins) {
+  Register object = ToRegister(ins->object());
+  Register output = ToRegister(ins->output());
+
+  masm.setIsCrossRealmArrayConstructor(object, output);
+}
+
+static void EmitObjectIsArray(MacroAssembler& masm, OutOfLineCode* ool,
+                              Register obj, Register output,
+                              Label* notArray = nullptr) {
+  masm.loadObjClassUnsafe(obj, output);
+
+  Label isArray;
+  masm.branchPtr(Assembler::Equal, output, ImmPtr(&ArrayObject::class_),
+                 &isArray);
+
+  // Branch to OOL path if it's a proxy.
+  masm.branchTestClassIsProxy(true, output, ool->entry());
+
+  if (notArray) {
+    masm.bind(notArray);
+  }
+  masm.move32(Imm32(0), output);
+  masm.jump(ool->rejoin());
+
+  masm.bind(&isArray);
+  masm.move32(Imm32(1), output);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitIsArrayO(LIsArrayO* lir) {
+  Register object = ToRegister(lir->object());
+  Register output = ToRegister(lir->output());
+
+  using Fn = bool (*)(JSContext*, HandleObject, bool*);
+  OutOfLineCode* ool = oolCallVM<Fn, js::IsArrayFromJit>(
+      lir, ArgList(object), StoreRegisterTo(output));
+  EmitObjectIsArray(masm, ool, object, output);
+}
+
+void CodeGenerator::visitIsArrayV(LIsArrayV* lir) {
+  ValueOperand val = ToValue(lir, LIsArrayV::ValueIndex);
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  Label notArray;
+  masm.fallibleUnboxObject(val, temp, &notArray);
+
+  using Fn = bool (*)(JSContext*, HandleObject, bool*);
+  OutOfLineCode* ool = oolCallVM<Fn, js::IsArrayFromJit>(
+      lir, ArgList(temp), StoreRegisterTo(output));
+  EmitObjectIsArray(masm, ool, temp, output, &notArray);
+}
+
+void CodeGenerator::visitIsTypedArray(LIsTypedArray* lir) {
+  Register object = ToRegister(lir->object());
+  Register output = ToRegister(lir->output());
+
+  OutOfLineCode* ool = nullptr;
+  if (lir->mir()->isPossiblyWrapped()) {
+    using Fn = bool (*)(JSContext*, JSObject*, bool*);
+    ool = oolCallVM<Fn, jit::IsPossiblyWrappedTypedArray>(
+        lir, ArgList(object), StoreRegisterTo(output));
+  }
+
+  Label notTypedArray;
+  Label done;
+
+  masm.loadObjClassUnsafe(object, output);
+  masm.branchIfClassIsNotTypedArray(output, &notTypedArray);
+
+  masm.move32(Imm32(1), output);
+  masm.jump(&done);
+  masm.bind(&notTypedArray);
+  if (ool) {
+    masm.branchTestClassIsProxy(true, output, ool->entry());
+  }
+  masm.move32(Imm32(0), output);
+  masm.bind(&done);
+  if (ool) {
+    masm.bind(ool->rejoin());
+  }
+}
+
+void CodeGenerator::visitIsObject(LIsObject* ins) {
+  Register output = ToRegister(ins->output());
+  ValueOperand value = ToValue(ins, LIsObject::ObjectIndex);
+  masm.testObjectSet(Assembler::Equal, value, output);
+}
+
+void CodeGenerator::visitIsObjectAndBranch(LIsObjectAndBranch* ins) {
+  ValueOperand value = ToValue(ins, LIsObjectAndBranch::Input);
+  testObjectEmitBranch(Assembler::Equal, value, ins->ifTrue(), ins->ifFalse());
+}
+
+void CodeGenerator::visitIsNullOrUndefined(LIsNullOrUndefined* ins) {
+  Register output = ToRegister(ins->output());
+  ValueOperand value = ToValue(ins, LIsNullOrUndefined::InputIndex);
+
+  Label isNotNull, done;
+  masm.branchTestNull(Assembler::NotEqual, value, &isNotNull);
+
+  masm.move32(Imm32(1), output);
+  masm.jump(&done);
+
+  masm.bind(&isNotNull);
+  masm.testUndefinedSet(Assembler::Equal, value, output);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitIsNullOrUndefinedAndBranch(
+    LIsNullOrUndefinedAndBranch* ins) {
+  Label* ifTrue = getJumpLabelForBranch(ins->ifTrue());
+  Label* ifFalse = getJumpLabelForBranch(ins->ifFalse());
+  ValueOperand value = ToValue(ins, LIsNullOrUndefinedAndBranch::Input);
+
+  ScratchTagScope tag(masm, value);
+  masm.splitTagForTest(value, tag);
+
+  masm.branchTestNull(Assembler::Equal, tag, ifTrue);
+  masm.branchTestUndefined(Assembler::Equal, tag, ifTrue);
+
+  if (!isNextBlock(ins->ifFalse()->lir())) {
+    masm.jump(ifFalse);
+  }
+}
+
+void CodeGenerator::loadOutermostJSScript(Register reg) {
+  // The "outermost" JSScript means the script that we are compiling
+  // basically; this is not always the script associated with the
+  // current basic block, which might be an inlined script.
+
+  MIRGraph& graph = current->mir()->graph();
+  MBasicBlock* entryBlock = graph.entryBlock();
+  masm.movePtr(ImmGCPtr(entryBlock->info().script()), reg);
+}
+
+void CodeGenerator::loadJSScriptForBlock(MBasicBlock* block, Register reg) {
+  // The current JSScript means the script for the current
+  // basic block. This may be an inlined script.
+
+  JSScript* script = block->info().script();
+  masm.movePtr(ImmGCPtr(script), reg);
+}
+
+void CodeGenerator::visitHasClass(LHasClass* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register output = ToRegister(ins->output());
+
+  masm.loadObjClassUnsafe(lhs, output);
+  masm.cmpPtrSet(Assembler::Equal, output, ImmPtr(ins->mir()->getClass()),
+                 output);
+}
+
+void CodeGenerator::visitGuardToClass(LGuardToClass* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register temp = ToRegister(ins->temp0());
+
+  // branchTestObjClass may zero the object register on speculative paths
+  // (we should have a defineReuseInput allocation in this case).
+  Register spectreRegToZero = lhs;
+
+  Label notEqual;
+
+  masm.branchTestObjClass(Assembler::NotEqual, lhs, ins->mir()->getClass(),
+                          temp, spectreRegToZero, &notEqual);
+
+  // Can't return null-return here, so bail.
+  bailoutFrom(&notEqual, ins->snapshot());
+}
+
+void CodeGenerator::visitGuardToFunction(LGuardToFunction* ins) {
+  Register lhs = ToRegister(ins->lhs());
+  Register temp = ToRegister(ins->temp0());
+
+  // branchTestObjClass may zero the object register on speculative paths
+  // (we should have a defineReuseInput allocation in this case).
+  Register spectreRegToZero = lhs;
+
+  Label notEqual;
+
+  masm.branchTestObjIsFunction(Assembler::NotEqual, lhs, temp, spectreRegToZero,
+                               &notEqual);
+
+  // Can't return null-return here, so bail.
+  bailoutFrom(&notEqual, ins->snapshot());
+}
+
+void CodeGenerator::visitObjectClassToString(LObjectClassToString* lir) {
+  Register obj = ToRegister(lir->lhs());
+  Register temp = ToRegister(lir->temp0());
+
+  using Fn = JSString* (*)(JSContext*, JSObject*);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp);
+  masm.passABIArg(temp);
+  masm.passABIArg(obj);
+  masm.callWithABI<Fn, js::ObjectClassToString>();
+
+  bailoutCmpPtr(Assembler::Equal, ReturnReg, ImmWord(0), lir->snapshot());
+}
+
+void CodeGenerator::visitWasmParameter(LWasmParameter* lir) {}
+
+void CodeGenerator::visitWasmParameterI64(LWasmParameterI64* lir) {}
+
+void CodeGenerator::visitWasmReturn(LWasmReturn* lir) {
+  // Don't emit a jump to the return label if this is the last block.
+  if (current->mir() != *gen->graph().poBegin()) {
+    masm.jump(&returnLabel_);
+  }
+}
+
+void CodeGenerator::visitWasmReturnI64(LWasmReturnI64* lir) {
+  // Don't emit a jump to the return label if this is the last block.
+  if (current->mir() != *gen->graph().poBegin()) {
+    masm.jump(&returnLabel_);
+  }
+}
+
+void CodeGenerator::visitWasmReturnVoid(LWasmReturnVoid* lir) {
+  // Don't emit a jump to the return label if this is the last block.
+  if (current->mir() != *gen->graph().poBegin()) {
+    masm.jump(&returnLabel_);
+  }
+}
+
+void CodeGenerator::emitAssertRangeI(MIRType type, const Range* r,
+                                     Register input) {
+  // Check the lower bound.
+  if (r->hasInt32LowerBound() && r->lower() > INT32_MIN) {
+    Label success;
+    if (type == MIRType::Int32 || type == MIRType::Boolean) {
+      masm.branch32(Assembler::GreaterThanOrEqual, input, Imm32(r->lower()),
+                    &success);
+    } else {
+      MOZ_ASSERT(type == MIRType::IntPtr);
+      masm.branchPtr(Assembler::GreaterThanOrEqual, input, Imm32(r->lower()),
+                     &success);
+    }
+    masm.assumeUnreachable(
+        "Integer input should be equal or higher than Lowerbound.");
+    masm.bind(&success);
+  }
+
+  // Check the upper bound.
+  if (r->hasInt32UpperBound() && r->upper() < INT32_MAX) {
+    Label success;
+    if (type == MIRType::Int32 || type == MIRType::Boolean) {
+      masm.branch32(Assembler::LessThanOrEqual, input, Imm32(r->upper()),
+                    &success);
+    } else {
+      MOZ_ASSERT(type == MIRType::IntPtr);
+      masm.branchPtr(Assembler::LessThanOrEqual, input, Imm32(r->upper()),
+                     &success);
+    }
+    masm.assumeUnreachable(
+        "Integer input should be lower or equal than Upperbound.");
+    masm.bind(&success);
+  }
+
+  // For r->canHaveFractionalPart(), r->canBeNegativeZero(), and
+  // r->exponent(), there's nothing to check, because if we ended up in the
+  // integer range checking code, the value is already in an integer register
+  // in the integer range.
+}
+
+void CodeGenerator::emitAssertRangeD(const Range* r, FloatRegister input,
+                                     FloatRegister temp) {
+  // Check the lower bound.
+  if (r->hasInt32LowerBound()) {
+    Label success;
+    masm.loadConstantDouble(r->lower(), temp);
+    if (r->canBeNaN()) {
+      masm.branchDouble(Assembler::DoubleUnordered, input, input, &success);
+    }
+    masm.branchDouble(Assembler::DoubleGreaterThanOrEqual, input, temp,
+                      &success);
+    masm.assumeUnreachable(
+        "Double input should be equal or higher than Lowerbound.");
+    masm.bind(&success);
+  }
+  // Check the upper bound.
+  if (r->hasInt32UpperBound()) {
+    Label success;
+    masm.loadConstantDouble(r->upper(), temp);
+    if (r->canBeNaN()) {
+      masm.branchDouble(Assembler::DoubleUnordered, input, input, &success);
+    }
+    masm.branchDouble(Assembler::DoubleLessThanOrEqual, input, temp, &success);
+    masm.assumeUnreachable(
+        "Double input should be lower or equal than Upperbound.");
+    masm.bind(&success);
+  }
+
+  // This code does not yet check r->canHaveFractionalPart(). This would require
+  // new assembler interfaces to make rounding instructions available.
+
+  if (!r->canBeNegativeZero()) {
+    Label success;
+
+    // First, test for being equal to 0.0, which also includes -0.0.
+    masm.loadConstantDouble(0.0, temp);
+    masm.branchDouble(Assembler::DoubleNotEqualOrUnordered, input, temp,
+                      &success);
+
+    // The easiest way to distinguish -0.0 from 0.0 is that 1.0/-0.0 is
+    // -Infinity instead of Infinity.
+    masm.loadConstantDouble(1.0, temp);
+    masm.divDouble(input, temp);
+    masm.branchDouble(Assembler::DoubleGreaterThan, temp, input, &success);
+
+    masm.assumeUnreachable("Input shouldn't be negative zero.");
+
+    masm.bind(&success);
+  }
+
+  if (!r->hasInt32Bounds() && !r->canBeInfiniteOrNaN() &&
+      r->exponent() < FloatingPoint<double>::kExponentBias) {
+    // Check the bounds implied by the maximum exponent.
+    Label exponentLoOk;
+    masm.loadConstantDouble(pow(2.0, r->exponent() + 1), temp);
+    masm.branchDouble(Assembler::DoubleUnordered, input, input, &exponentLoOk);
+    masm.branchDouble(Assembler::DoubleLessThanOrEqual, input, temp,
+                      &exponentLoOk);
+    masm.assumeUnreachable("Check for exponent failed.");
+    masm.bind(&exponentLoOk);
+
+    Label exponentHiOk;
+    masm.loadConstantDouble(-pow(2.0, r->exponent() + 1), temp);
+    masm.branchDouble(Assembler::DoubleUnordered, input, input, &exponentHiOk);
+    masm.branchDouble(Assembler::DoubleGreaterThanOrEqual, input, temp,
+                      &exponentHiOk);
+    masm.assumeUnreachable("Check for exponent failed.");
+    masm.bind(&exponentHiOk);
+  } else if (!r->hasInt32Bounds() && !r->canBeNaN()) {
+    // If we think the value can't be NaN, check that it isn't.
+    Label notnan;
+    masm.branchDouble(Assembler::DoubleOrdered, input, input, &notnan);
+    masm.assumeUnreachable("Input shouldn't be NaN.");
+    masm.bind(&notnan);
+
+    // If we think the value also can't be an infinity, check that it isn't.
+    if (!r->canBeInfiniteOrNaN()) {
+      Label notposinf;
+      masm.loadConstantDouble(PositiveInfinity<double>(), temp);
+      masm.branchDouble(Assembler::DoubleLessThan, input, temp, &notposinf);
+      masm.assumeUnreachable("Input shouldn't be +Inf.");
+      masm.bind(&notposinf);
+
+      Label notneginf;
+      masm.loadConstantDouble(NegativeInfinity<double>(), temp);
+      masm.branchDouble(Assembler::DoubleGreaterThan, input, temp, &notneginf);
+      masm.assumeUnreachable("Input shouldn't be -Inf.");
+      masm.bind(&notneginf);
+    }
+  }
+}
+
+void CodeGenerator::visitAssertClass(LAssertClass* ins) {
+  Register obj = ToRegister(ins->input());
+  Register temp = ToRegister(ins->getTemp(0));
+
+  Label success;
+  if (ins->mir()->getClass() == &FunctionClass) {
+    // Allow both possible function classes here.
+    masm.branchTestObjIsFunctionNoSpectreMitigations(Assembler::Equal, obj,
+                                                     temp, &success);
+  } else {
+    masm.branchTestObjClassNoSpectreMitigations(
+        Assembler::Equal, obj, ins->mir()->getClass(), temp, &success);
+  }
+  masm.assumeUnreachable("Wrong KnownClass during run-time");
+  masm.bind(&success);
+}
+
+void CodeGenerator::visitAssertShape(LAssertShape* ins) {
+  Register obj = ToRegister(ins->input());
+
+  Label success;
+  masm.branchTestObjShapeNoSpectreMitigations(Assembler::Equal, obj,
+                                              ins->mir()->shape(), &success);
+  masm.assumeUnreachable("Wrong Shape during run-time");
+  masm.bind(&success);
+}
+
+void CodeGenerator::visitAssertRangeI(LAssertRangeI* ins) {
+  Register input = ToRegister(ins->input());
+  const Range* r = ins->range();
+
+  emitAssertRangeI(ins->mir()->input()->type(), r, input);
+}
+
+void CodeGenerator::visitAssertRangeD(LAssertRangeD* ins) {
+  FloatRegister input = ToFloatRegister(ins->input());
+  FloatRegister temp = ToFloatRegister(ins->temp());
+  const Range* r = ins->range();
+
+  emitAssertRangeD(r, input, temp);
+}
+
+void CodeGenerator::visitAssertRangeF(LAssertRangeF* ins) {
+  FloatRegister input = ToFloatRegister(ins->input());
+  FloatRegister temp = ToFloatRegister(ins->temp());
+  FloatRegister temp2 = ToFloatRegister(ins->temp2());
+
+  const Range* r = ins->range();
+
+  masm.convertFloat32ToDouble(input, temp);
+  emitAssertRangeD(r, temp, temp2);
+}
+
+void CodeGenerator::visitAssertRangeV(LAssertRangeV* ins) {
+  const Range* r = ins->range();
+  const ValueOperand value = ToValue(ins, LAssertRangeV::Input);
+  Label done;
+
+  {
+    ScratchTagScope tag(masm, value);
+    masm.splitTagForTest(value, tag);
+
+    {
+      Label isNotInt32;
+      masm.branchTestInt32(Assembler::NotEqual, tag, &isNotInt32);
+      {
+        ScratchTagScopeRelease _(&tag);
+        Register unboxInt32 = ToTempUnboxRegister(ins->temp());
+        Register input = masm.extractInt32(value, unboxInt32);
+        emitAssertRangeI(MIRType::Int32, r, input);
+        masm.jump(&done);
+      }
+      masm.bind(&isNotInt32);
+    }
+
+    {
+      Label isNotDouble;
+      masm.branchTestDouble(Assembler::NotEqual, tag, &isNotDouble);
+      {
+        ScratchTagScopeRelease _(&tag);
+        FloatRegister input = ToFloatRegister(ins->floatTemp1());
+        FloatRegister temp = ToFloatRegister(ins->floatTemp2());
+        masm.unboxDouble(value, input);
+        emitAssertRangeD(r, input, temp);
+        masm.jump(&done);
+      }
+      masm.bind(&isNotDouble);
+    }
+  }
+
+  masm.assumeUnreachable("Incorrect range for Value.");
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitInterruptCheck(LInterruptCheck* lir) {
+  using Fn = bool (*)(JSContext*);
+  OutOfLineCode* ool =
+      oolCallVM<Fn, InterruptCheck>(lir, ArgList(), StoreNothing());
+
+  const void* interruptAddr = gen->runtime->addressOfInterruptBits();
+  masm.branch32(Assembler::NotEqual, AbsoluteAddress(interruptAddr), Imm32(0),
+                ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineResumableWasmTrap(
+    OutOfLineResumableWasmTrap* ool) {
+  LInstruction* lir = ool->lir();
+  masm.wasmTrap(ool->trap(), ool->bytecodeOffset());
+
+  markSafepointAt(masm.currentOffset(), lir);
+
+  // Note that masm.framePushed() doesn't include the register dump area.
+  // That will be taken into account when the StackMap is created from the
+  // LSafepoint.
+  lir->safepoint()->setFramePushedAtStackMapBase(ool->framePushed());
+  lir->safepoint()->setIsWasmTrap();
+
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitOutOfLineAbortingWasmTrap(
+    OutOfLineAbortingWasmTrap* ool) {
+  masm.wasmTrap(ool->trap(), ool->bytecodeOffset());
+}
+
+void CodeGenerator::visitWasmInterruptCheck(LWasmInterruptCheck* lir) {
+  MOZ_ASSERT(gen->compilingWasm());
+
+  OutOfLineResumableWasmTrap* ool = new (alloc()) OutOfLineResumableWasmTrap(
+      lir, masm.framePushed(), lir->mir()->bytecodeOffset(),
+      wasm::Trap::CheckInterrupt);
+  addOutOfLineCode(ool, lir->mir());
+  masm.branch32(
+      Assembler::NotEqual,
+      Address(ToRegister(lir->instance()), wasm::Instance::offsetOfInterrupt()),
+      Imm32(0), ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitWasmTrap(LWasmTrap* lir) {
+  MOZ_ASSERT(gen->compilingWasm());
+  const MWasmTrap* mir = lir->mir();
+
+  masm.wasmTrap(mir->trap(), mir->bytecodeOffset());
+}
+
+void CodeGenerator::visitWasmTrapIfNull(LWasmTrapIfNull* lir) {
+  MOZ_ASSERT(gen->compilingWasm());
+  const MWasmTrapIfNull* mir = lir->mir();
+  Label nonNull;
+  Register input = ToRegister(lir->object());
+
+  masm.branchTestPtr(Assembler::NonZero, input, input, &nonNull);
+  masm.wasmTrap(mir->trap(), mir->bytecodeOffset());
+  masm.bind(&nonNull);
+}
+
+void CodeGenerator::visitWasmGcObjectIsSubtypeOfAbstract(
+    LWasmGcObjectIsSubtypeOfAbstract* ins) {
+  MOZ_ASSERT(gen->compilingWasm());
+
+  const MWasmGcObjectIsSubtypeOfAbstract* mir = ins->mir();
+  MOZ_ASSERT(!mir->destType().isTypeRef());
+
+  Register object = ToRegister(ins->object());
+  Register superSuperTypeVector = Register::Invalid();
+  Register scratch1 = ToTempRegisterOrInvalid(ins->temp0());
+  Register scratch2 = Register::Invalid();
+  Register result = ToRegister(ins->output());
+  Label onSuccess;
+  Label onFail;
+  Label join;
+  masm.branchWasmGcObjectIsRefType(
+      object, mir->sourceType(), mir->destType(), &onSuccess,
+      /*onSuccess=*/true, superSuperTypeVector, scratch1, scratch2);
+  masm.bind(&onFail);
+  masm.xor32(result, result);
+  masm.jump(&join);
+  masm.bind(&onSuccess);
+  masm.move32(Imm32(1), result);
+  masm.bind(&join);
+}
+
+void CodeGenerator::visitWasmGcObjectIsSubtypeOfConcrete(
+    LWasmGcObjectIsSubtypeOfConcrete* ins) {
+  MOZ_ASSERT(gen->compilingWasm());
+
+  const MWasmGcObjectIsSubtypeOfConcrete* mir = ins->mir();
+  MOZ_ASSERT(mir->destType().isTypeRef());
+
+  Register object = ToRegister(ins->object());
+  Register superSuperTypeVector = ToRegister(ins->superSuperTypeVector());
+  Register scratch1 = ToRegister(ins->temp0());
+  Register scratch2 = ToTempRegisterOrInvalid(ins->temp1());
+  Register result = ToRegister(ins->output());
+  Label onSuccess;
+  Label join;
+  masm.branchWasmGcObjectIsRefType(
+      object, mir->sourceType(), mir->destType(), &onSuccess,
+      /*onSuccess=*/true, superSuperTypeVector, scratch1, scratch2);
+  masm.move32(Imm32(0), result);
+  masm.jump(&join);
+  masm.bind(&onSuccess);
+  masm.move32(Imm32(1), result);
+  masm.bind(&join);
+}
+
+void CodeGenerator::visitWasmGcObjectIsSubtypeOfAbstractAndBranch(
+    LWasmGcObjectIsSubtypeOfAbstractAndBranch* ins) {
+  MOZ_ASSERT(gen->compilingWasm());
+  Register object = ToRegister(ins->object());
+  Register scratch1 = ToTempRegisterOrInvalid(ins->temp0());
+  Label* onSuccess = getJumpLabelForBranch(ins->ifTrue());
+  Label* onFail = getJumpLabelForBranch(ins->ifFalse());
+  masm.branchWasmGcObjectIsRefType(
+      object, ins->sourceType(), ins->destType(), onSuccess,
+      /*onSuccess=*/true, Register::Invalid(), scratch1, Register::Invalid());
+  masm.jump(onFail);
+}
+
+void CodeGenerator::visitWasmGcObjectIsSubtypeOfConcreteAndBranch(
+    LWasmGcObjectIsSubtypeOfConcreteAndBranch* ins) {
+  MOZ_ASSERT(gen->compilingWasm());
+  Register object = ToRegister(ins->object());
+  Register superSuperTypeVector = ToRegister(ins->superSuperTypeVector());
+  Register scratch1 = ToRegister(ins->temp0());
+  Register scratch2 = ToTempRegisterOrInvalid(ins->temp1());
+  Label* onSuccess = getJumpLabelForBranch(ins->ifTrue());
+  Label* onFail = getJumpLabelForBranch(ins->ifFalse());
+  masm.branchWasmGcObjectIsRefType(
+      object, ins->sourceType(), ins->destType(), onSuccess,
+      /*onSuccess=*/true, superSuperTypeVector, scratch1, scratch2);
+  masm.jump(onFail);
+}
+
+void CodeGenerator::visitWasmBoundsCheck(LWasmBoundsCheck* ins) {
+  const MWasmBoundsCheck* mir = ins->mir();
+  Register ptr = ToRegister(ins->ptr());
+  Register boundsCheckLimit = ToRegister(ins->boundsCheckLimit());
+  // When there are no spectre mitigations in place, branching out-of-line to
+  // the trap is a big performance win, but with mitigations it's trickier.  See
+  // bug 1680243.
+  if (JitOptions.spectreIndexMasking) {
+    Label ok;
+    masm.wasmBoundsCheck32(Assembler::Below, ptr, boundsCheckLimit, &ok);
+    masm.wasmTrap(wasm::Trap::OutOfBounds, mir->bytecodeOffset());
+    masm.bind(&ok);
+  } else {
+    OutOfLineAbortingWasmTrap* ool = new (alloc()) OutOfLineAbortingWasmTrap(
+        mir->bytecodeOffset(), wasm::Trap::OutOfBounds);
+    addOutOfLineCode(ool, mir);
+    masm.wasmBoundsCheck32(Assembler::AboveOrEqual, ptr, boundsCheckLimit,
+                           ool->entry());
+  }
+}
+
+void CodeGenerator::visitWasmBoundsCheck64(LWasmBoundsCheck64* ins) {
+  const MWasmBoundsCheck* mir = ins->mir();
+  Register64 ptr = ToRegister64(ins->ptr());
+  Register64 boundsCheckLimit = ToRegister64(ins->boundsCheckLimit());
+  // See above.
+  if (JitOptions.spectreIndexMasking) {
+    Label ok;
+    masm.wasmBoundsCheck64(Assembler::Below, ptr, boundsCheckLimit, &ok);
+    masm.wasmTrap(wasm::Trap::OutOfBounds, mir->bytecodeOffset());
+    masm.bind(&ok);
+  } else {
+    OutOfLineAbortingWasmTrap* ool = new (alloc()) OutOfLineAbortingWasmTrap(
+        mir->bytecodeOffset(), wasm::Trap::OutOfBounds);
+    addOutOfLineCode(ool, mir);
+    masm.wasmBoundsCheck64(Assembler::AboveOrEqual, ptr, boundsCheckLimit,
+                           ool->entry());
+  }
+}
+
+void CodeGenerator::visitWasmAlignmentCheck(LWasmAlignmentCheck* ins) {
+  const MWasmAlignmentCheck* mir = ins->mir();
+  Register ptr = ToRegister(ins->ptr());
+  OutOfLineAbortingWasmTrap* ool = new (alloc()) OutOfLineAbortingWasmTrap(
+      mir->bytecodeOffset(), wasm::Trap::UnalignedAccess);
+  addOutOfLineCode(ool, mir);
+  masm.branchTest32(Assembler::NonZero, ptr, Imm32(mir->byteSize() - 1),
+                    ool->entry());
+}
+
+void CodeGenerator::visitWasmAlignmentCheck64(LWasmAlignmentCheck64* ins) {
+  const MWasmAlignmentCheck* mir = ins->mir();
+  Register64 ptr = ToRegister64(ins->ptr());
+#ifdef JS_64BIT
+  Register r = ptr.reg;
+#else
+  Register r = ptr.low;
+#endif
+  OutOfLineAbortingWasmTrap* ool = new (alloc()) OutOfLineAbortingWasmTrap(
+      mir->bytecodeOffset(), wasm::Trap::UnalignedAccess);
+  addOutOfLineCode(ool, mir);
+  masm.branchTestPtr(Assembler::NonZero, r, Imm32(mir->byteSize() - 1),
+                     ool->entry());
+}
+
+void CodeGenerator::visitWasmLoadInstance(LWasmLoadInstance* ins) {
+  switch (ins->mir()->type()) {
+    case MIRType::RefOrNull:
+    case MIRType::Pointer:
+      masm.loadPtr(Address(ToRegister(ins->instance()), ins->mir()->offset()),
+                   ToRegister(ins->output()));
+      break;
+    case MIRType::Int32:
+      masm.load32(Address(ToRegister(ins->instance()), ins->mir()->offset()),
+                  ToRegister(ins->output()));
+      break;
+    default:
+      MOZ_CRASH("MIRType not supported in WasmLoadInstance");
+  }
+}
+
+void CodeGenerator::visitWasmLoadInstance64(LWasmLoadInstance64* ins) {
+  MOZ_ASSERT(ins->mir()->type() == MIRType::Int64);
+  masm.load64(Address(ToRegister(ins->instance()), ins->mir()->offset()),
+              ToOutRegister64(ins));
+}
+
+void CodeGenerator::incrementWarmUpCounter(AbsoluteAddress warmUpCount,
+                                           JSScript* script, Register tmp) {
+  // The code depends on the JitScript* not being discarded without also
+  // invalidating Ion code. Assert this.
+#ifdef DEBUG
+  Label ok;
+  masm.movePtr(ImmGCPtr(script), tmp);
+  masm.loadJitScript(tmp, tmp);
+  masm.branchPtr(Assembler::Equal, tmp, ImmPtr(script->jitScript()), &ok);
+  masm.assumeUnreachable("Didn't find JitScript?");
+  masm.bind(&ok);
+#endif
+
+  masm.load32(warmUpCount, tmp);
+  masm.add32(Imm32(1), tmp);
+  masm.store32(tmp, warmUpCount);
+}
+
+void CodeGenerator::visitIncrementWarmUpCounter(LIncrementWarmUpCounter* ins) {
+  Register tmp = ToRegister(ins->temp0());
+
+  AbsoluteAddress warmUpCount =
+      AbsoluteAddress(ins->mir()->script()->jitScript())
+          .offset(JitScript::offsetOfWarmUpCount());
+  incrementWarmUpCounter(warmUpCount, ins->mir()->script(), tmp);
+}
+
+void CodeGenerator::visitLexicalCheck(LLexicalCheck* ins) {
+  ValueOperand inputValue = ToValue(ins, LLexicalCheck::InputIndex);
+  Label bail;
+  masm.branchTestMagicValue(Assembler::Equal, inputValue,
+                            JS_UNINITIALIZED_LEXICAL, &bail);
+  bailoutFrom(&bail, ins->snapshot());
+}
+
+void CodeGenerator::visitThrowRuntimeLexicalError(
+    LThrowRuntimeLexicalError* ins) {
+  pushArg(Imm32(ins->mir()->errorNumber()));
+
+  using Fn = bool (*)(JSContext*, unsigned);
+  callVM<Fn, jit::ThrowRuntimeLexicalError>(ins);
+}
+
+void CodeGenerator::visitThrowMsg(LThrowMsg* ins) {
+  pushArg(Imm32(static_cast<int32_t>(ins->mir()->throwMsgKind())));
+
+  using Fn = bool (*)(JSContext*, unsigned);
+  callVM<Fn, js::ThrowMsgOperation>(ins);
+}
+
+void CodeGenerator::visitGlobalDeclInstantiation(
+    LGlobalDeclInstantiation* ins) {
+  pushArg(ImmPtr(ins->mir()->resumePoint()->pc()));
+  pushArg(ImmGCPtr(ins->mir()->block()->info().script()));
+
+  using Fn = bool (*)(JSContext*, HandleScript, const jsbytecode*);
+  callVM<Fn, GlobalDeclInstantiationFromIon>(ins);
+}
+
+void CodeGenerator::visitDebugger(LDebugger* ins) {
+  Register cx = ToRegister(ins->temp0());
+
+  masm.loadJSContext(cx);
+  using Fn = bool (*)(JSContext* cx);
+  masm.setupAlignedABICall();
+  masm.passABIArg(cx);
+  masm.callWithABI<Fn, GlobalHasLiveOnDebuggerStatement>();
+
+  Label bail;
+  masm.branchIfTrueBool(ReturnReg, &bail);
+  bailoutFrom(&bail, ins->snapshot());
+}
+
+void CodeGenerator::visitNewTarget(LNewTarget* ins) {
+  ValueOperand output = ToOutValue(ins);
+
+  // if (isConstructing) output = argv[Max(numActualArgs, numFormalArgs)]
+  Label notConstructing, done;
+  Address calleeToken(FramePointer, JitFrameLayout::offsetOfCalleeToken());
+  masm.branchTestPtr(Assembler::Zero, calleeToken,
+                     Imm32(CalleeToken_FunctionConstructing), &notConstructing);
+
+  Register argvLen = output.scratchReg();
+  masm.loadNumActualArgs(FramePointer, argvLen);
+
+  Label useNFormals;
+
+  size_t numFormalArgs = ins->mirRaw()->block()->info().nargs();
+  masm.branchPtr(Assembler::Below, argvLen, Imm32(numFormalArgs), &useNFormals);
+
+  size_t argsOffset = JitFrameLayout::offsetOfActualArgs();
+  {
+    BaseValueIndex newTarget(FramePointer, argvLen, argsOffset);
+    masm.loadValue(newTarget, output);
+    masm.jump(&done);
+  }
+
+  masm.bind(&useNFormals);
+
+  {
+    Address newTarget(FramePointer,
+                      argsOffset + (numFormalArgs * sizeof(Value)));
+    masm.loadValue(newTarget, output);
+    masm.jump(&done);
+  }
+
+  // else output = undefined
+  masm.bind(&notConstructing);
+  masm.moveValue(UndefinedValue(), output);
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitCheckReturn(LCheckReturn* ins) {
+  ValueOperand returnValue = ToValue(ins, LCheckReturn::ReturnValueIndex);
+  ValueOperand thisValue = ToValue(ins, LCheckReturn::ThisValueIndex);
+  ValueOperand output = ToOutValue(ins);
+
+  using Fn = bool (*)(JSContext*, HandleValue);
+  OutOfLineCode* ool = oolCallVM<Fn, ThrowBadDerivedReturnOrUninitializedThis>(
+      ins, ArgList(returnValue), StoreNothing());
+
+  Label noChecks;
+  masm.branchTestObject(Assembler::Equal, returnValue, &noChecks);
+  masm.branchTestUndefined(Assembler::NotEqual, returnValue, ool->entry());
+  masm.branchTestMagic(Assembler::Equal, thisValue, ool->entry());
+  masm.moveValue(thisValue, output);
+  masm.jump(ool->rejoin());
+  masm.bind(&noChecks);
+  masm.moveValue(returnValue, output);
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCheckIsObj(LCheckIsObj* ins) {
+  ValueOperand value = ToValue(ins, LCheckIsObj::ValueIndex);
+  Register output = ToRegister(ins->output());
+
+  using Fn = bool (*)(JSContext*, CheckIsObjectKind);
+  OutOfLineCode* ool = oolCallVM<Fn, ThrowCheckIsObject>(
+      ins, ArgList(Imm32(ins->mir()->checkKind())), StoreNothing());
+
+  masm.fallibleUnboxObject(value, output, ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCheckObjCoercible(LCheckObjCoercible* ins) {
+  ValueOperand checkValue = ToValue(ins, LCheckObjCoercible::ValueIndex);
+
+  using Fn = bool (*)(JSContext*, HandleValue);
+  OutOfLineCode* ool = oolCallVM<Fn, ThrowObjectCoercible>(
+      ins, ArgList(checkValue), StoreNothing());
+  masm.branchTestNull(Assembler::Equal, checkValue, ool->entry());
+  masm.branchTestUndefined(Assembler::Equal, checkValue, ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCheckClassHeritage(LCheckClassHeritage* ins) {
+  ValueOperand heritage = ToValue(ins, LCheckClassHeritage::HeritageIndex);
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+
+  using Fn = bool (*)(JSContext*, HandleValue);
+  OutOfLineCode* ool = oolCallVM<Fn, CheckClassHeritageOperation>(
+      ins, ArgList(heritage), StoreNothing());
+
+  masm.branchTestNull(Assembler::Equal, heritage, ool->rejoin());
+  masm.fallibleUnboxObject(heritage, temp0, ool->entry());
+
+  masm.isConstructor(temp0, temp1, ool->entry());
+  masm.branchTest32(Assembler::Zero, temp1, temp1, ool->entry());
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCheckThis(LCheckThis* ins) {
+  ValueOperand thisValue = ToValue(ins, LCheckThis::ValueIndex);
+
+  using Fn = bool (*)(JSContext*);
+  OutOfLineCode* ool =
+      oolCallVM<Fn, ThrowUninitializedThis>(ins, ArgList(), StoreNothing());
+  masm.branchTestMagic(Assembler::Equal, thisValue, ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitCheckThisReinit(LCheckThisReinit* ins) {
+  ValueOperand thisValue = ToValue(ins, LCheckThisReinit::ThisValueIndex);
+
+  using Fn = bool (*)(JSContext*);
+  OutOfLineCode* ool =
+      oolCallVM<Fn, ThrowInitializedThis>(ins, ArgList(), StoreNothing());
+  masm.branchTestMagic(Assembler::NotEqual, thisValue, ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitGenerator(LGenerator* lir) {
+  Register callee = ToRegister(lir->callee());
+  Register environmentChain = ToRegister(lir->environmentChain());
+  Register argsObject = ToRegister(lir->argsObject());
+
+  pushArg(argsObject);
+  pushArg(environmentChain);
+  pushArg(ImmGCPtr(current->mir()->info().script()));
+  pushArg(callee);
+
+  using Fn = JSObject* (*)(JSContext* cx, HandleFunction, HandleScript,
+                           HandleObject, HandleObject);
+  callVM<Fn, CreateGenerator>(lir);
+}
+
+void CodeGenerator::visitAsyncResolve(LAsyncResolve* lir) {
+  Register generator = ToRegister(lir->generator());
+  ValueOperand valueOrReason = ToValue(lir, LAsyncResolve::ValueOrReasonIndex);
+  AsyncFunctionResolveKind resolveKind = lir->mir()->resolveKind();
+
+  pushArg(Imm32(static_cast<int32_t>(resolveKind)));
+  pushArg(valueOrReason);
+  pushArg(generator);
+
+  using Fn = JSObject* (*)(JSContext*, Handle<AsyncFunctionGeneratorObject*>,
+                           HandleValue, AsyncFunctionResolveKind);
+  callVM<Fn, js::AsyncFunctionResolve>(lir);
+}
+
+void CodeGenerator::visitAsyncAwait(LAsyncAwait* lir) {
+  ValueOperand value = ToValue(lir, LAsyncAwait::ValueIndex);
+  Register generator = ToRegister(lir->generator());
+
+  pushArg(value);
+  pushArg(generator);
+
+  using Fn =
+      JSObject* (*)(JSContext* cx, Handle<AsyncFunctionGeneratorObject*> genObj,
+                    HandleValue value);
+  callVM<Fn, js::AsyncFunctionAwait>(lir);
+}
+
+void CodeGenerator::visitCanSkipAwait(LCanSkipAwait* lir) {
+  ValueOperand value = ToValue(lir, LCanSkipAwait::ValueIndex);
+
+  pushArg(value);
+
+  using Fn = bool (*)(JSContext*, HandleValue, bool* canSkip);
+  callVM<Fn, js::CanSkipAwait>(lir);
+}
+
+void CodeGenerator::visitMaybeExtractAwaitValue(LMaybeExtractAwaitValue* lir) {
+  ValueOperand value = ToValue(lir, LMaybeExtractAwaitValue::ValueIndex);
+  ValueOperand output = ToOutValue(lir);
+  Register canSkip = ToRegister(lir->canSkip());
+
+  Label cantExtract, finished;
+  masm.branchIfFalseBool(canSkip, &cantExtract);
+
+  pushArg(value);
+
+  using Fn = bool (*)(JSContext*, HandleValue, MutableHandleValue);
+  callVM<Fn, js::ExtractAwaitValue>(lir);
+  masm.jump(&finished);
+  masm.bind(&cantExtract);
+
+  masm.moveValue(value, output);
+
+  masm.bind(&finished);
+}
+
+void CodeGenerator::visitDebugCheckSelfHosted(LDebugCheckSelfHosted* ins) {
+  ValueOperand checkValue = ToValue(ins, LDebugCheckSelfHosted::ValueIndex);
+  pushArg(checkValue);
+  using Fn = bool (*)(JSContext*, HandleValue);
+  callVM<Fn, js::Debug_CheckSelfHosted>(ins);
+}
+
+void CodeGenerator::visitRandom(LRandom* ins) {
+  using mozilla::non_crypto::XorShift128PlusRNG;
+
+  FloatRegister output = ToFloatRegister(ins->output());
+  Register rngReg = ToRegister(ins->temp0());
+
+  Register64 temp1 = ToRegister64(ins->temp1());
+  Register64 temp2 = ToRegister64(ins->temp2());
+
+  const XorShift128PlusRNG* rng = gen->realm->addressOfRandomNumberGenerator();
+  masm.movePtr(ImmPtr(rng), rngReg);
+
+  masm.randomDouble(rngReg, output, temp1, temp2);
+  if (js::SupportDifferentialTesting()) {
+    masm.loadConstantDouble(0.0, output);
+  }
+}
+
+void CodeGenerator::visitSignExtendInt32(LSignExtendInt32* ins) {
+  Register input = ToRegister(ins->input());
+  Register output = ToRegister(ins->output());
+
+  switch (ins->mode()) {
+    case MSignExtendInt32::Byte:
+      masm.move8SignExtend(input, output);
+      break;
+    case MSignExtendInt32::Half:
+      masm.move16SignExtend(input, output);
+      break;
+  }
+}
+
+void CodeGenerator::visitRotate(LRotate* ins) {
+  MRotate* mir = ins->mir();
+  Register input = ToRegister(ins->input());
+  Register dest = ToRegister(ins->output());
+
+  const LAllocation* count = ins->count();
+  if (count->isConstant()) {
+    int32_t c = ToInt32(count) & 0x1F;
+    if (mir->isLeftRotate()) {
+      masm.rotateLeft(Imm32(c), input, dest);
+    } else {
+      masm.rotateRight(Imm32(c), input, dest);
+    }
+  } else {
+    Register creg = ToRegister(count);
+    if (mir->isLeftRotate()) {
+      masm.rotateLeft(creg, input, dest);
+    } else {
+      masm.rotateRight(creg, input, dest);
+    }
+  }
+}
+
+class OutOfLineNaNToZero : public OutOfLineCodeBase<CodeGenerator> {
+  LNaNToZero* lir_;
+
+ public:
+  explicit OutOfLineNaNToZero(LNaNToZero* lir) : lir_(lir) {}
+
+  void accept(CodeGenerator* codegen) override {
+    codegen->visitOutOfLineNaNToZero(this);
+  }
+  LNaNToZero* lir() const { return lir_; }
+};
+
+void CodeGenerator::visitOutOfLineNaNToZero(OutOfLineNaNToZero* ool) {
+  FloatRegister output = ToFloatRegister(ool->lir()->output());
+  masm.loadConstantDouble(0.0, output);
+  masm.jump(ool->rejoin());
+}
+
+void CodeGenerator::visitNaNToZero(LNaNToZero* lir) {
+  FloatRegister input = ToFloatRegister(lir->input());
+
+  OutOfLineNaNToZero* ool = new (alloc()) OutOfLineNaNToZero(lir);
+  addOutOfLineCode(ool, lir->mir());
+
+  if (lir->mir()->operandIsNeverNegativeZero()) {
+    masm.branchDouble(Assembler::DoubleUnordered, input, input, ool->entry());
+  } else {
+    FloatRegister scratch = ToFloatRegister(lir->temp0());
+    masm.loadConstantDouble(0.0, scratch);
+    masm.branchDouble(Assembler::DoubleEqualOrUnordered, input, scratch,
+                      ool->entry());
+  }
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitIsPackedArray(LIsPackedArray* lir) {
+  Register obj = ToRegister(lir->object());
+  Register output = ToRegister(lir->output());
+  Register temp = ToRegister(lir->temp0());
+
+  masm.setIsPackedArray(obj, output, temp);
+}
+
+void CodeGenerator::visitGuardArrayIsPacked(LGuardArrayIsPacked* lir) {
+  Register array = ToRegister(lir->array());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+
+  Label bail;
+  masm.branchArrayIsNotPacked(array, temp0, temp1, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGetPrototypeOf(LGetPrototypeOf* lir) {
+  Register target = ToRegister(lir->target());
+  ValueOperand out = ToOutValue(lir);
+  Register scratch = out.scratchReg();
+
+  using Fn = bool (*)(JSContext*, HandleObject, MutableHandleValue);
+  OutOfLineCode* ool = oolCallVM<Fn, jit::GetPrototypeOf>(lir, ArgList(target),
+                                                          StoreValueTo(out));
+
+  MOZ_ASSERT(uintptr_t(TaggedProto::LazyProto) == 1);
+
+  masm.loadObjProto(target, scratch);
+
+  Label hasProto;
+  masm.branchPtr(Assembler::Above, scratch, ImmWord(1), &hasProto);
+
+  // Call into the VM for lazy prototypes.
+  masm.branchPtr(Assembler::Equal, scratch, ImmWord(1), ool->entry());
+
+  masm.moveValue(NullValue(), out);
+  masm.jump(ool->rejoin());
+
+  masm.bind(&hasProto);
+  masm.tagValue(JSVAL_TYPE_OBJECT, scratch, out);
+
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitObjectWithProto(LObjectWithProto* lir) {
+  pushArg(ToValue(lir, LObjectWithProto::PrototypeIndex));
+
+  using Fn = PlainObject* (*)(JSContext*, HandleValue);
+  callVM<Fn, js::ObjectWithProtoOperation>(lir);
+}
+
+void CodeGenerator::visitObjectStaticProto(LObjectStaticProto* lir) {
+  Register obj = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+
+  masm.loadObjProto(obj, output);
+
+#ifdef DEBUG
+  // We shouldn't encounter a null or lazy proto.
+  MOZ_ASSERT(uintptr_t(TaggedProto::LazyProto) == 1);
+
+  Label done;
+  masm.branchPtr(Assembler::Above, output, ImmWord(1), &done);
+  masm.assumeUnreachable("Unexpected null or lazy proto in MObjectStaticProto");
+  masm.bind(&done);
+#endif
+}
+
+void CodeGenerator::visitBuiltinObject(LBuiltinObject* lir) {
+  pushArg(Imm32(static_cast<int32_t>(lir->mir()->builtinObjectKind())));
+
+  using Fn = JSObject* (*)(JSContext*, BuiltinObjectKind);
+  callVM<Fn, js::BuiltinObjectOperation>(lir);
+}
+
+void CodeGenerator::visitSuperFunction(LSuperFunction* lir) {
+  Register callee = ToRegister(lir->callee());
+  ValueOperand out = ToOutValue(lir);
+  Register temp = ToRegister(lir->temp0());
+
+#ifdef DEBUG
+  Label classCheckDone;
+  masm.branchTestObjIsFunction(Assembler::Equal, callee, temp, callee,
+                               &classCheckDone);
+  masm.assumeUnreachable("Unexpected non-JSFunction callee in JSOp::SuperFun");
+  masm.bind(&classCheckDone);
+#endif
+
+  // Load prototype of callee
+  masm.loadObjProto(callee, temp);
+
+#ifdef DEBUG
+  // We won't encounter a lazy proto, because |callee| is guaranteed to be a
+  // JSFunction and only proxy objects can have a lazy proto.
+  MOZ_ASSERT(uintptr_t(TaggedProto::LazyProto) == 1);
+
+  Label proxyCheckDone;
+  masm.branchPtr(Assembler::NotEqual, temp, ImmWord(1), &proxyCheckDone);
+  masm.assumeUnreachable("Unexpected lazy proto in JSOp::SuperFun");
+  masm.bind(&proxyCheckDone);
+#endif
+
+  Label nullProto, done;
+  masm.branchPtr(Assembler::Equal, temp, ImmWord(0), &nullProto);
+
+  // Box prototype and return
+  masm.tagValue(JSVAL_TYPE_OBJECT, temp, out);
+  masm.jump(&done);
+
+  masm.bind(&nullProto);
+  masm.moveValue(NullValue(), out);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitInitHomeObject(LInitHomeObject* lir) {
+  Register func = ToRegister(lir->function());
+  ValueOperand homeObject = ToValue(lir, LInitHomeObject::HomeObjectIndex);
+
+  masm.assertFunctionIsExtended(func);
+
+  Address addr(func, FunctionExtended::offsetOfMethodHomeObjectSlot());
+
+  emitPreBarrier(addr);
+  masm.storeValue(homeObject, addr);
+}
+
+void CodeGenerator::visitIsTypedArrayConstructor(
+    LIsTypedArrayConstructor* lir) {
+  Register object = ToRegister(lir->object());
+  Register output = ToRegister(lir->output());
+
+  masm.setIsDefinitelyTypedArrayConstructor(object, output);
+}
+
+void CodeGenerator::visitLoadValueTag(LLoadValueTag* lir) {
+  ValueOperand value = ToValue(lir, LLoadValueTag::ValueIndex);
+  Register output = ToRegister(lir->output());
+
+  Register tag = masm.extractTag(value, output);
+  if (tag != output) {
+    masm.mov(tag, output);
+  }
+}
+
+void CodeGenerator::visitGuardTagNotEqual(LGuardTagNotEqual* lir) {
+  Register lhs = ToRegister(lir->lhs());
+  Register rhs = ToRegister(lir->rhs());
+
+  bailoutCmp32(Assembler::Equal, lhs, rhs, lir->snapshot());
+
+  // If both lhs and rhs are numbers, can't use tag comparison to do inequality
+  // comparison
+  Label done;
+  masm.branchTestNumber(Assembler::NotEqual, lhs, &done);
+  masm.branchTestNumber(Assembler::NotEqual, rhs, &done);
+  bailout(lir->snapshot());
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitLoadWrapperTarget(LLoadWrapperTarget* lir) {
+  Register object = ToRegister(lir->object());
+  Register output = ToRegister(lir->output());
+
+  masm.loadPtr(Address(object, ProxyObject::offsetOfReservedSlots()), output);
+  masm.unboxObject(
+      Address(output, js::detail::ProxyReservedSlots::offsetOfPrivateSlot()),
+      output);
+}
+
+void CodeGenerator::visitGuardHasGetterSetter(LGuardHasGetterSetter* lir) {
+  Register object = ToRegister(lir->object());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register temp2 = ToRegister(lir->temp2());
+
+  masm.movePropertyKey(lir->mir()->propId(), temp1);
+  masm.movePtr(ImmGCPtr(lir->mir()->getterSetter()), temp2);
+
+  using Fn = bool (*)(JSContext* cx, JSObject* obj, jsid id,
+                      GetterSetter* getterSetter);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp0);
+  masm.passABIArg(temp0);
+  masm.passABIArg(object);
+  masm.passABIArg(temp1);
+  masm.passABIArg(temp2);
+  masm.callWithABI<Fn, ObjectHasGetterSetterPure>();
+
+  bailoutIfFalseBool(ReturnReg, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardIsExtensible(LGuardIsExtensible* lir) {
+  Register object = ToRegister(lir->object());
+  Register temp = ToRegister(lir->temp0());
+
+  Label bail;
+  masm.branchIfObjectNotExtensible(object, temp, &bail);
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitGuardInt32IsNonNegative(
+    LGuardInt32IsNonNegative* lir) {
+  Register index = ToRegister(lir->index());
+
+  bailoutCmp32(Assembler::LessThan, index, Imm32(0), lir->snapshot());
+}
+
+void CodeGenerator::visitGuardInt32Range(LGuardInt32Range* lir) {
+  Register input = ToRegister(lir->input());
+
+  bailoutCmp32(Assembler::LessThan, input, Imm32(lir->mir()->minimum()),
+               lir->snapshot());
+  bailoutCmp32(Assembler::GreaterThan, input, Imm32(lir->mir()->maximum()),
+               lir->snapshot());
+}
+
+void CodeGenerator::visitGuardIndexIsNotDenseElement(
+    LGuardIndexIsNotDenseElement* lir) {
+  Register object = ToRegister(lir->object());
+  Register index = ToRegister(lir->index());
+  Register temp = ToRegister(lir->temp0());
+  Register spectreTemp = ToTempRegisterOrInvalid(lir->temp1());
+
+  // Load obj->elements.
+  masm.loadPtr(Address(object, NativeObject::offsetOfElements()), temp);
+
+  // Ensure index >= initLength or the element is a hole.
+  Label notDense;
+  Address capacity(temp, ObjectElements::offsetOfInitializedLength());
+  masm.spectreBoundsCheck32(index, capacity, spectreTemp, &notDense);
+
+  BaseValueIndex element(temp, index);
+  masm.branchTestMagic(Assembler::Equal, element, &notDense);
+
+  bailout(lir->snapshot());
+
+  masm.bind(&notDense);
+}
+
+void CodeGenerator::visitGuardIndexIsValidUpdateOrAdd(
+    LGuardIndexIsValidUpdateOrAdd* lir) {
+  Register object = ToRegister(lir->object());
+  Register index = ToRegister(lir->index());
+  Register temp = ToRegister(lir->temp0());
+  Register spectreTemp = ToTempRegisterOrInvalid(lir->temp1());
+
+  // Load obj->elements.
+  masm.loadPtr(Address(object, NativeObject::offsetOfElements()), temp);
+
+  Label success;
+
+  // If length is writable, branch to &success.  All indices are writable.
+  Address flags(temp, ObjectElements::offsetOfFlags());
+  masm.branchTest32(Assembler::Zero, flags,
+                    Imm32(ObjectElements::Flags::NONWRITABLE_ARRAY_LENGTH),
+                    &success);
+
+  // Otherwise, ensure index is in bounds.
+  Label bail;
+  Address length(temp, ObjectElements::offsetOfLength());
+  masm.spectreBoundsCheck32(index, length, spectreTemp, &bail);
+  masm.bind(&success);
+
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitCallAddOrUpdateSparseElement(
+    LCallAddOrUpdateSparseElement* lir) {
+  Register object = ToRegister(lir->object());
+  Register index = ToRegister(lir->index());
+  ValueOperand value = ToValue(lir, LCallAddOrUpdateSparseElement::ValueIndex);
+
+  pushArg(Imm32(lir->mir()->strict()));
+  pushArg(value);
+  pushArg(index);
+  pushArg(object);
+
+  using Fn =
+      bool (*)(JSContext*, Handle<NativeObject*>, int32_t, HandleValue, bool);
+  callVM<Fn, js::AddOrUpdateSparseElementHelper>(lir);
+}
+
+void CodeGenerator::visitCallGetSparseElement(LCallGetSparseElement* lir) {
+  Register object = ToRegister(lir->object());
+  Register index = ToRegister(lir->index());
+
+  pushArg(index);
+  pushArg(object);
+
+  using Fn =
+      bool (*)(JSContext*, Handle<NativeObject*>, int32_t, MutableHandleValue);
+  callVM<Fn, js::GetSparseElementHelper>(lir);
+}
+
+void CodeGenerator::visitCallNativeGetElement(LCallNativeGetElement* lir) {
+  Register object = ToRegister(lir->object());
+  Register index = ToRegister(lir->index());
+
+  pushArg(index);
+  pushArg(TypedOrValueRegister(MIRType::Object, AnyRegister(object)));
+  pushArg(object);
+
+  using Fn = bool (*)(JSContext*, Handle<NativeObject*>, HandleValue, int32_t,
+                      MutableHandleValue);
+  callVM<Fn, js::NativeGetElement>(lir);
+}
+
+void CodeGenerator::visitCallNativeGetElementSuper(
+    LCallNativeGetElementSuper* lir) {
+  Register object = ToRegister(lir->object());
+  Register index = ToRegister(lir->index());
+  ValueOperand receiver =
+      ToValue(lir, LCallNativeGetElementSuper::ReceiverIndex);
+
+  pushArg(index);
+  pushArg(receiver);
+  pushArg(object);
+
+  using Fn = bool (*)(JSContext*, Handle<NativeObject*>, HandleValue, int32_t,
+                      MutableHandleValue);
+  callVM<Fn, js::NativeGetElement>(lir);
+}
+
+void CodeGenerator::visitCallObjectHasSparseElement(
+    LCallObjectHasSparseElement* lir) {
+  Register object = ToRegister(lir->object());
+  Register index = ToRegister(lir->index());
+  Register temp0 = ToRegister(lir->temp0());
+  Register temp1 = ToRegister(lir->temp1());
+  Register output = ToRegister(lir->output());
+
+  masm.reserveStack(sizeof(Value));
+  masm.moveStackPtrTo(temp1);
+
+  using Fn = bool (*)(JSContext*, NativeObject*, int32_t, Value*);
+  masm.setupAlignedABICall();
+  masm.loadJSContext(temp0);
+  masm.passABIArg(temp0);
+  masm.passABIArg(object);
+  masm.passABIArg(index);
+  masm.passABIArg(temp1);
+  masm.callWithABI<Fn, HasNativeElementPure>();
+  masm.storeCallPointerResult(temp0);
+
+  Label bail, ok;
+  uint32_t framePushed = masm.framePushed();
+  masm.branchIfTrueBool(temp0, &ok);
+  masm.adjustStack(sizeof(Value));
+  masm.jump(&bail);
+
+  masm.bind(&ok);
+  masm.setFramePushed(framePushed);
+  masm.unboxBoolean(Address(masm.getStackPointer(), 0), output);
+  masm.adjustStack(sizeof(Value));
+
+  bailoutFrom(&bail, lir->snapshot());
+}
+
+void CodeGenerator::visitBigIntAsIntN(LBigIntAsIntN* ins) {
+  Register bits = ToRegister(ins->bits());
+  Register input = ToRegister(ins->input());
+
+  pushArg(bits);
+  pushArg(input);
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, int32_t);
+  callVM<Fn, jit::BigIntAsIntN>(ins);
+}
+
+void CodeGenerator::visitBigIntAsIntN64(LBigIntAsIntN64* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp = ToRegister(ins->temp());
+  Register64 temp64 = ToRegister64(ins->temp64());
+  Register output = ToRegister(ins->output());
+
+  Label done, create;
+
+  masm.movePtr(input, output);
+
+  // Load the BigInt value as an int64.
+  masm.loadBigInt64(input, temp64);
+
+  // Create a new BigInt when the input exceeds the int64 range.
+  masm.branch32(Assembler::Above, Address(input, BigInt::offsetOfLength()),
+                Imm32(64 / BigInt::DigitBits), &create);
+
+  // And create a new BigInt when the value and the BigInt have different signs.
+  Label nonNegative;
+  masm.branchIfBigIntIsNonNegative(input, &nonNegative);
+  masm.branchTest64(Assembler::NotSigned, temp64, temp64, temp, &create);
+  masm.jump(&done);
+
+  masm.bind(&nonNegative);
+  masm.branchTest64(Assembler::NotSigned, temp64, temp64, temp, &done);
+
+  masm.bind(&create);
+  emitCreateBigInt(ins, Scalar::BigInt64, temp64, output, temp);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitBigIntAsIntN32(LBigIntAsIntN32* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp = ToRegister(ins->temp());
+  Register64 temp64 = ToRegister64(ins->temp64());
+  Register output = ToRegister(ins->output());
+
+  Label done, create;
+
+  masm.movePtr(input, output);
+
+  // Load the absolute value of the first digit.
+  masm.loadFirstBigIntDigitOrZero(input, temp);
+
+  // If the absolute value exceeds the int32 range, create a new BigInt.
+  masm.branchPtr(Assembler::Above, temp, Imm32(INT32_MAX), &create);
+
+  // Also create a new BigInt if we have more than one digit.
+  masm.branch32(Assembler::BelowOrEqual,
+                Address(input, BigInt::offsetOfLength()), Imm32(1), &done);
+
+  masm.bind(&create);
+
+  // |temp| stores the absolute value, negate it when the sign flag is set.
+  Label nonNegative;
+  masm.branchIfBigIntIsNonNegative(input, &nonNegative);
+  masm.negPtr(temp);
+  masm.bind(&nonNegative);
+
+  masm.move32To64SignExtend(temp, temp64);
+  emitCreateBigInt(ins, Scalar::BigInt64, temp64, output, temp);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitBigIntAsUintN(LBigIntAsUintN* ins) {
+  Register bits = ToRegister(ins->bits());
+  Register input = ToRegister(ins->input());
+
+  pushArg(bits);
+  pushArg(input);
+
+  using Fn = BigInt* (*)(JSContext*, HandleBigInt, int32_t);
+  callVM<Fn, jit::BigIntAsUintN>(ins);
+}
+
+void CodeGenerator::visitBigIntAsUintN64(LBigIntAsUintN64* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp = ToRegister(ins->temp());
+  Register64 temp64 = ToRegister64(ins->temp64());
+  Register output = ToRegister(ins->output());
+
+  Label done, create;
+
+  masm.movePtr(input, output);
+
+  // Load the BigInt value as an uint64.
+  masm.loadBigInt64(input, temp64);
+
+  // Create a new BigInt when the input exceeds the uint64 range.
+  masm.branch32(Assembler::Above, Address(input, BigInt::offsetOfLength()),
+                Imm32(64 / BigInt::DigitBits), &create);
+
+  // And create a new BigInt when the input has the sign flag set.
+  masm.branchIfBigIntIsNonNegative(input, &done);
+
+  masm.bind(&create);
+  emitCreateBigInt(ins, Scalar::BigUint64, temp64, output, temp);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitBigIntAsUintN32(LBigIntAsUintN32* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp = ToRegister(ins->temp());
+  Register64 temp64 = ToRegister64(ins->temp64());
+  Register output = ToRegister(ins->output());
+
+  Label done, create;
+
+  masm.movePtr(input, output);
+
+  // Load the absolute value of the first digit.
+  masm.loadFirstBigIntDigitOrZero(input, temp);
+
+  // If the absolute value exceeds the uint32 range, create a new BigInt.
+#if JS_PUNBOX64
+  masm.branchPtr(Assembler::Above, temp, ImmWord(UINT32_MAX), &create);
+#endif
+
+  // Also create a new BigInt if we have more than one digit.
+  masm.branch32(Assembler::Above, Address(input, BigInt::offsetOfLength()),
+                Imm32(1), &create);
+
+  // And create a new BigInt when the input has the sign flag set.
+  masm.branchIfBigIntIsNonNegative(input, &done);
+
+  masm.bind(&create);
+
+  // |temp| stores the absolute value, negate it when the sign flag is set.
+  Label nonNegative;
+  masm.branchIfBigIntIsNonNegative(input, &nonNegative);
+  masm.negPtr(temp);
+  masm.bind(&nonNegative);
+
+  masm.move32To64ZeroExtend(temp, temp64);
+  emitCreateBigInt(ins, Scalar::BigUint64, temp64, output, temp);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitGuardNonGCThing(LGuardNonGCThing* ins) {
+  ValueOperand input = ToValue(ins, LGuardNonGCThing::InputIndex);
+
+  Label bail;
+  masm.branchTestGCThing(Assembler::Equal, input, &bail);
+  bailoutFrom(&bail, ins->snapshot());
+}
+
+void CodeGenerator::visitToHashableNonGCThing(LToHashableNonGCThing* ins) {
+  ValueOperand input = ToValue(ins, LToHashableNonGCThing::InputIndex);
+  FloatRegister tempFloat = ToFloatRegister(ins->temp0());
+  ValueOperand output = ToOutValue(ins);
+
+  masm.toHashableNonGCThing(input, output, tempFloat);
+}
+
+void CodeGenerator::visitToHashableString(LToHashableString* ins) {
+  Register input = ToRegister(ins->input());
+  Register output = ToRegister(ins->output());
+
+  using Fn = JSAtom* (*)(JSContext*, JSString*);
+  auto* ool = oolCallVM<Fn, js::AtomizeString>(ins, ArgList(input),
+                                               StoreRegisterTo(output));
+
+  masm.branchTest32(Assembler::Zero, Address(input, JSString::offsetOfFlags()),
+                    Imm32(JSString::ATOM_BIT), ool->entry());
+  masm.movePtr(input, output);
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::visitToHashableValue(LToHashableValue* ins) {
+  ValueOperand input = ToValue(ins, LToHashableValue::InputIndex);
+  FloatRegister tempFloat = ToFloatRegister(ins->temp0());
+  ValueOperand output = ToOutValue(ins);
+
+  Register str = output.scratchReg();
+
+  using Fn = JSAtom* (*)(JSContext*, JSString*);
+  auto* ool =
+      oolCallVM<Fn, js::AtomizeString>(ins, ArgList(str), StoreRegisterTo(str));
+
+  masm.toHashableValue(input, output, tempFloat, ool->entry(), ool->rejoin());
+}
+
+void CodeGenerator::visitHashNonGCThing(LHashNonGCThing* ins) {
+  ValueOperand input = ToValue(ins, LHashNonGCThing::InputIndex);
+  Register temp = ToRegister(ins->temp0());
+  Register output = ToRegister(ins->output());
+
+  masm.prepareHashNonGCThing(input, output, temp);
+}
+
+void CodeGenerator::visitHashString(LHashString* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp = ToRegister(ins->temp0());
+  Register output = ToRegister(ins->output());
+
+  masm.prepareHashString(input, output, temp);
+}
+
+void CodeGenerator::visitHashSymbol(LHashSymbol* ins) {
+  Register input = ToRegister(ins->input());
+  Register output = ToRegister(ins->output());
+
+  masm.prepareHashSymbol(input, output);
+}
+
+void CodeGenerator::visitHashBigInt(LHashBigInt* ins) {
+  Register input = ToRegister(ins->input());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register output = ToRegister(ins->output());
+
+  masm.prepareHashBigInt(input, output, temp0, temp1, temp2);
+}
+
+void CodeGenerator::visitHashObject(LHashObject* ins) {
+  Register setObj = ToRegister(ins->setObject());
+  ValueOperand input = ToValue(ins, LHashObject::InputIndex);
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  Register output = ToRegister(ins->output());
+
+  masm.prepareHashObject(setObj, input, output, temp0, temp1, temp2, temp3);
+}
+
+void CodeGenerator::visitHashValue(LHashValue* ins) {
+  Register setObj = ToRegister(ins->setObject());
+  ValueOperand input = ToValue(ins, LHashValue::InputIndex);
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  Register output = ToRegister(ins->output());
+
+  masm.prepareHashValue(setObj, input, output, temp0, temp1, temp2, temp3);
+}
+
+void CodeGenerator::visitSetObjectHasNonBigInt(LSetObjectHasNonBigInt* ins) {
+  Register setObj = ToRegister(ins->setObject());
+  ValueOperand input = ToValue(ins, LSetObjectHasNonBigInt::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register output = ToRegister(ins->output());
+
+  masm.setObjectHasNonBigInt(setObj, input, hash, output, temp0, temp1);
+}
+
+void CodeGenerator::visitSetObjectHasBigInt(LSetObjectHasBigInt* ins) {
+  Register setObj = ToRegister(ins->setObject());
+  ValueOperand input = ToValue(ins, LSetObjectHasBigInt::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  Register output = ToRegister(ins->output());
+
+  masm.setObjectHasBigInt(setObj, input, hash, output, temp0, temp1, temp2,
+                          temp3);
+}
+
+void CodeGenerator::visitSetObjectHasValue(LSetObjectHasValue* ins) {
+  Register setObj = ToRegister(ins->setObject());
+  ValueOperand input = ToValue(ins, LSetObjectHasValue::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  Register output = ToRegister(ins->output());
+
+  masm.setObjectHasValue(setObj, input, hash, output, temp0, temp1, temp2,
+                         temp3);
+}
+
+void CodeGenerator::visitSetObjectHasValueVMCall(
+    LSetObjectHasValueVMCall* ins) {
+  pushArg(ToValue(ins, LSetObjectHasValueVMCall::InputIndex));
+  pushArg(ToRegister(ins->setObject()));
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleValue, bool*);
+  callVM<Fn, jit::SetObjectHas>(ins);
+}
+
+void CodeGenerator::visitSetObjectSize(LSetObjectSize* ins) {
+  Register setObj = ToRegister(ins->setObject());
+  Register output = ToRegister(ins->output());
+
+  masm.loadSetObjectSize(setObj, output);
+}
+
+void CodeGenerator::visitMapObjectHasNonBigInt(LMapObjectHasNonBigInt* ins) {
+  Register mapObj = ToRegister(ins->mapObject());
+  ValueOperand input = ToValue(ins, LMapObjectHasNonBigInt::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register output = ToRegister(ins->output());
+
+  masm.mapObjectHasNonBigInt(mapObj, input, hash, output, temp0, temp1);
+}
+
+void CodeGenerator::visitMapObjectHasBigInt(LMapObjectHasBigInt* ins) {
+  Register mapObj = ToRegister(ins->mapObject());
+  ValueOperand input = ToValue(ins, LMapObjectHasBigInt::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  Register output = ToRegister(ins->output());
+
+  masm.mapObjectHasBigInt(mapObj, input, hash, output, temp0, temp1, temp2,
+                          temp3);
+}
+
+void CodeGenerator::visitMapObjectHasValue(LMapObjectHasValue* ins) {
+  Register mapObj = ToRegister(ins->mapObject());
+  ValueOperand input = ToValue(ins, LMapObjectHasValue::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  Register output = ToRegister(ins->output());
+
+  masm.mapObjectHasValue(mapObj, input, hash, output, temp0, temp1, temp2,
+                         temp3);
+}
+
+void CodeGenerator::visitMapObjectHasValueVMCall(
+    LMapObjectHasValueVMCall* ins) {
+  pushArg(ToValue(ins, LMapObjectHasValueVMCall::InputIndex));
+  pushArg(ToRegister(ins->mapObject()));
+
+  using Fn = bool (*)(JSContext*, HandleObject, HandleValue, bool*);
+  callVM<Fn, jit::MapObjectHas>(ins);
+}
+
+void CodeGenerator::visitMapObjectGetNonBigInt(LMapObjectGetNonBigInt* ins) {
+  Register mapObj = ToRegister(ins->mapObject());
+  ValueOperand input = ToValue(ins, LMapObjectGetNonBigInt::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  ValueOperand output = ToOutValue(ins);
+
+  masm.mapObjectGetNonBigInt(mapObj, input, hash, output, temp0, temp1,
+                             output.scratchReg());
+}
+
+void CodeGenerator::visitMapObjectGetBigInt(LMapObjectGetBigInt* ins) {
+  Register mapObj = ToRegister(ins->mapObject());
+  ValueOperand input = ToValue(ins, LMapObjectGetBigInt::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  ValueOperand output = ToOutValue(ins);
+
+  masm.mapObjectGetBigInt(mapObj, input, hash, output, temp0, temp1, temp2,
+                          temp3, output.scratchReg());
+}
+
+void CodeGenerator::visitMapObjectGetValue(LMapObjectGetValue* ins) {
+  Register mapObj = ToRegister(ins->mapObject());
+  ValueOperand input = ToValue(ins, LMapObjectGetValue::InputIndex);
+  Register hash = ToRegister(ins->hash());
+  Register temp0 = ToRegister(ins->temp0());
+  Register temp1 = ToRegister(ins->temp1());
+  Register temp2 = ToRegister(ins->temp2());
+  Register temp3 = ToRegister(ins->temp3());
+  ValueOperand output = ToOutValue(ins);
+
+  masm.mapObjectGetValue(mapObj, input, hash, output, temp0, temp1, temp2,
+                         temp3, output.scratchReg());
+}
+
+void CodeGenerator::visitMapObjectGetValueVMCall(
+    LMapObjectGetValueVMCall* ins) {
+  pushArg(ToValue(ins, LMapObjectGetValueVMCall::InputIndex));
+  pushArg(ToRegister(ins->mapObject()));
+
+  using Fn =
+      bool (*)(JSContext*, HandleObject, HandleValue, MutableHandleValue);
+  callVM<Fn, jit::MapObjectGet>(ins);
+}
+
+void CodeGenerator::visitMapObjectSize(LMapObjectSize* ins) {
+  Register mapObj = ToRegister(ins->mapObject());
+  Register output = ToRegister(ins->output());
+
+  masm.loadMapObjectSize(mapObj, output);
+}
+
+template <size_t NumDefs>
+void CodeGenerator::emitIonToWasmCallBase(LIonToWasmCallBase<NumDefs>* lir) {
+  wasm::JitCallStackArgVector stackArgs;
+  masm.propagateOOM(stackArgs.reserve(lir->numOperands()));
+  if (masm.oom()) {
+    return;
+  }
+
+  MIonToWasmCall* mir = lir->mir();
+  const wasm::FuncExport& funcExport = mir->funcExport();
+  const wasm::FuncType& sig =
+      mir->instance()->metadata().getFuncExportType(funcExport);
+
+  WasmABIArgGenerator abi;
+  for (size_t i = 0; i < lir->numOperands(); i++) {
+    MIRType argMir;
+    switch (sig.args()[i].kind()) {
+      case wasm::ValType::I32:
+      case wasm::ValType::I64:
+      case wasm::ValType::F32:
+      case wasm::ValType::F64:
+        argMir = sig.args()[i].toMIRType();
+        break;
+      case wasm::ValType::V128:
+        MOZ_CRASH("unexpected argument type when calling from ion to wasm");
+      case wasm::ValType::Ref:
+        // temporarilyUnsupportedReftypeForEntry() restricts args to externref
+        MOZ_RELEASE_ASSERT(sig.args()[i].refType().isExtern());
+        // Argument is boxed on the JS side to an anyref, so passed as a
+        // pointer here.
+        argMir = sig.args()[i].toMIRType();
+        break;
+    }
+
+    ABIArg arg = abi.next(argMir);
+    switch (arg.kind()) {
+      case ABIArg::GPR:
+      case ABIArg::FPU: {
+        MOZ_ASSERT(ToAnyRegister(lir->getOperand(i)) == arg.reg());
+        stackArgs.infallibleEmplaceBack(wasm::JitCallStackArg());
+        break;
+      }
+      case ABIArg::Stack: {
+        const LAllocation* larg = lir->getOperand(i);
+        if (larg->isConstant()) {
+          stackArgs.infallibleEmplaceBack(ToInt32(larg));
+        } else if (larg->isGeneralReg()) {
+          stackArgs.infallibleEmplaceBack(ToRegister(larg));
+        } else if (larg->isFloatReg()) {
+          stackArgs.infallibleEmplaceBack(ToFloatRegister(larg));
+        } else {
+          // Always use the stack pointer here because GenerateDirectCallFromJit
+          // depends on this.
+          Address addr = ToAddress<BaseRegForAddress::SP>(larg);
+          stackArgs.infallibleEmplaceBack(addr);
+        }
+        break;
+      }
+#ifdef JS_CODEGEN_REGISTER_PAIR
+      case ABIArg::GPR_PAIR: {
+        MOZ_CRASH(
+            "no way to pass i64, and wasm uses hardfp for function calls");
+      }
+#endif
+      case ABIArg::Uninitialized: {
+        MOZ_CRASH("Uninitialized ABIArg kind");
+      }
+    }
+  }
+
+  const wasm::ValTypeVector& results = sig.results();
+  if (results.length() == 0) {
+    MOZ_ASSERT(lir->mir()->type() == MIRType::Value);
+  } else {
+    MOZ_ASSERT(results.length() == 1, "multi-value return unimplemented");
+    switch (results[0].kind()) {
+      case wasm::ValType::I32:
+        MOZ_ASSERT(lir->mir()->type() == MIRType::Int32);
+        MOZ_ASSERT(ToRegister(lir->output()) == ReturnReg);
+        break;
+      case wasm::ValType::I64:
+        MOZ_ASSERT(lir->mir()->type() == MIRType::Int64);
+        MOZ_ASSERT(ToOutRegister64(lir) == ReturnReg64);
+        break;
+      case wasm::ValType::F32:
+        MOZ_ASSERT(lir->mir()->type() == MIRType::Float32);
+        MOZ_ASSERT(ToFloatRegister(lir->output()) == ReturnFloat32Reg);
+        break;
+      case wasm::ValType::F64:
+        MOZ_ASSERT(lir->mir()->type() == MIRType::Double);
+        MOZ_ASSERT(ToFloatRegister(lir->output()) == ReturnDoubleReg);
+        break;
+      case wasm::ValType::V128:
+        MOZ_CRASH("unexpected return type when calling from ion to wasm");
+      case wasm::ValType::Ref:
+        // The wasm stubs layer unboxes anything that needs to be unboxed
+        // and leaves it in a Value.  A FuncRef/EqRef we could in principle
+        // leave it as a raw object pointer but for now it complicates the
+        // API to do so.
+        MOZ_ASSERT(lir->mir()->type() == MIRType::Value);
+        break;
+    }
+  }
+
+  WasmInstanceObject* instObj = lir->mir()->instanceObject();
+
+  Register scratch = ToRegister(lir->temp());
+
+  uint32_t callOffset;
+  ensureOsiSpace();
+  GenerateDirectCallFromJit(masm, funcExport, instObj->instance(), stackArgs,
+                            scratch, &callOffset);
+
+  // Add the instance object to the constant pool, so it is transferred to
+  // the owning IonScript and so that it gets traced as long as the IonScript
+  // lives.
+
+  uint32_t unused;
+  masm.propagateOOM(graph.addConstantToPool(ObjectValue(*instObj), &unused));
+
+  markSafepointAt(callOffset, lir);
+}
+
+void CodeGenerator::visitIonToWasmCall(LIonToWasmCall* lir) {
+  emitIonToWasmCallBase(lir);
+}
+void CodeGenerator::visitIonToWasmCallV(LIonToWasmCallV* lir) {
+  emitIonToWasmCallBase(lir);
+}
+void CodeGenerator::visitIonToWasmCallI64(LIonToWasmCallI64* lir) {
+  emitIonToWasmCallBase(lir);
+}
+
+void CodeGenerator::visitWasmNullConstant(LWasmNullConstant* lir) {
+  masm.xorPtr(ToRegister(lir->output()), ToRegister(lir->output()));
+}
+
+void CodeGenerator::visitWasmFence(LWasmFence* lir) {
+  MOZ_ASSERT(gen->compilingWasm());
+  masm.memoryBarrier(MembarFull);
+}
+
+void CodeGenerator::visitWasmBoxValue(LWasmBoxValue* lir) {
+  ValueOperand input = ToValue(lir, LWasmBoxValue::InputIndex);
+  Register output = ToRegister(lir->output());
+
+  Label nullValue, objectValue, done;
+  {
+    ScratchTagScope tag(masm, input);
+    masm.splitTagForTest(input, tag);
+    masm.branchTestObject(Assembler::Equal, tag, &objectValue);
+    masm.branchTestNull(Assembler::Equal, tag, &nullValue);
+  }
+
+  using Fn = JSObject* (*)(JSContext*, HandleValue);
+  OutOfLineCode* oolBoxValue = oolCallVM<Fn, wasm::BoxBoxableValue>(
+      lir, ArgList(input), StoreRegisterTo(output));
+
+  masm.jump(oolBoxValue->entry());
+
+  masm.bind(&nullValue);
+  // See the definition of AnyRef for a discussion of pointer representation.
+  masm.xorPtr(output, output);
+  masm.jump(&done);
+
+  masm.bind(&objectValue);
+  // See the definition of AnyRef for a discussion of pointer representation.
+  masm.unboxObject(input, output);
+
+  masm.bind(&done);
+  masm.bind(oolBoxValue->rejoin());
+}
+
+void CodeGenerator::visitWasmAnyRefFromJSObject(LWasmAnyRefFromJSObject* lir) {
+  Register input = ToRegister(lir->input());
+  Register output = ToRegister(lir->output());
+  // See the definition of AnyRef for a discussion of pointer representation.
+  if (input != output) {
+    masm.movePtr(input, output);
+  }
+}
+
+#ifdef FUZZING_JS_FUZZILLI
+void CodeGenerator::emitFuzzilliHashDouble(FloatRegister floatDouble,
+                                           Register scratch, Register output) {
+#  ifdef JS_PUNBOX64
+  Register64 reg64_1(scratch);
+  Register64 reg64_2(output);
+  masm.moveDoubleToGPR64(floatDouble, reg64_1);
+  masm.move64(reg64_1, reg64_2);
+  masm.rshift64(Imm32(32), reg64_2);
+  masm.add32(scratch, output);
+#  else
+  Register64 reg64(scratch, output);
+  masm.moveDoubleToGPR64(floatDouble, reg64);
+  masm.add32(scratch, output);
+#  endif
+}
+
+void CodeGenerator::emitFuzzilliHashObject(LInstruction* lir, Register obj,
+                                           Register output) {
+  using Fn = void (*)(JSContext* cx, JSObject* obj, uint32_t* out);
+  OutOfLineCode* ool = oolCallVM<Fn, FuzzilliHashObjectInl>(
+      lir, ArgList(obj), StoreRegisterTo(output));
+
+  masm.jump(ool->entry());
+  masm.bind(ool->rejoin());
+}
+
+void CodeGenerator::emitFuzzilliHashBigInt(Register bigInt, Register output) {
+  LiveRegisterSet volatileRegs(GeneralRegisterSet::All(),
+                               FloatRegisterSet::All());
+  volatileRegs.takeUnchecked(output);
+  masm.PushRegsInMask(volatileRegs);
+
+  using Fn = uint32_t (*)(BigInt* bigInt);
+  masm.setupUnalignedABICall(output);
+  masm.passABIArg(bigInt);
+  masm.callWithABI<Fn, js::FuzzilliHashBigInt>();
+  masm.storeCallInt32Result(output);
+
+  masm.PopRegsInMask(volatileRegs);
+}
+
+void CodeGenerator::visitFuzzilliHashV(LFuzzilliHashV* ins) {
+  MOZ_ASSERT(ins->mir()->getOperand(0)->type() == MIRType::Value);
+
+  ValueOperand value = ToValue(ins, 0);
+
+  Label isDouble, isObject, isBigInt, done;
+
+  FloatRegister scratchFloat = ToFloatRegister(ins->getTemp(1));
+  Register scratch = ToRegister(ins->getTemp(0));
+  Register output = ToRegister(ins->output());
+  MOZ_ASSERT(scratch != output);
+
+#  ifdef JS_PUNBOX64
+  Register tagReg = ToRegister(ins->getTemp(0));
+  masm.splitTag(value, tagReg);
+#  else
+  Register tagReg = value.typeReg();
+#  endif
+
+  Label noBigInt;
+  masm.branchTestBigInt(Assembler::NotEqual, tagReg, &noBigInt);
+  masm.unboxBigInt(value, scratch);
+  masm.jump(&isBigInt);
+  masm.bind(&noBigInt);
+
+  Label noObject;
+  masm.branchTestObject(Assembler::NotEqual, tagReg, &noObject);
+  masm.unboxObject(value, scratch);
+  masm.jump(&isObject);
+  masm.bind(&noObject);
+
+  Label noInt32;
+  masm.branchTestInt32(Assembler::NotEqual, tagReg, &noInt32);
+  masm.unboxInt32(value, scratch);
+  masm.convertInt32ToDouble(scratch, scratchFloat);
+  masm.jump(&isDouble);
+  masm.bind(&noInt32);
+
+  Label noNull;
+  masm.branchTestNull(Assembler::NotEqual, tagReg, &noNull);
+  masm.move32(Imm32(1), scratch);
+  masm.convertInt32ToDouble(scratch, scratchFloat);
+  masm.jump(&isDouble);
+  masm.bind(&noNull);
+
+  Label noUndefined;
+  masm.branchTestUndefined(Assembler::NotEqual, tagReg, &noUndefined);
+  masm.move32(Imm32(2), scratch);
+  masm.convertInt32ToDouble(scratch, scratchFloat);
+  masm.jump(&isDouble);
+  masm.bind(&noUndefined);
+
+  Label noBoolean;
+  masm.branchTestBoolean(Assembler::NotEqual, tagReg, &noBoolean);
+  masm.unboxBoolean(value, scratch);
+  masm.add32(Imm32(3), scratch);
+  masm.convertInt32ToDouble(scratch, scratchFloat);
+  masm.jump(&isDouble);
+  masm.bind(&noBoolean);
+
+  Label noDouble;
+  masm.branchTestDouble(Assembler::NotEqual, tagReg, &noDouble);
+  masm.unboxDouble(value, scratchFloat);
+  masm.canonicalizeDoubleIfDeterministic(scratchFloat);
+
+  masm.jump(&isDouble);
+  masm.bind(&noDouble);
+  masm.move32(Imm32(0), output);
+  masm.jump(&done);
+
+  masm.bind(&isBigInt);
+  emitFuzzilliHashBigInt(scratch, output);
+  masm.jump(&done);
+
+  masm.bind(&isObject);
+  emitFuzzilliHashObject(ins, scratch, output);
+  masm.jump(&done);
+
+  masm.bind(&isDouble);
+  emitFuzzilliHashDouble(scratchFloat, scratch, output);
+
+  masm.bind(&done);
+}
+
+void CodeGenerator::visitFuzzilliHashT(LFuzzilliHashT* ins) {
+  const LAllocation* value = ins->value();
+  MIRType mirType = ins->mir()->getOperand(0)->type();
+
+  FloatRegister scratchFloat = ToFloatRegister(ins->getTemp(1));
+  Register scratch = ToRegister(ins->getTemp(0));
+  Register output = ToRegister(ins->output());
+  MOZ_ASSERT(scratch != output);
+
+  if (mirType == MIRType::Object) {
+    MOZ_ASSERT(value->isGeneralReg());
+    masm.mov(value->toGeneralReg()->reg(), scratch);
+    emitFuzzilliHashObject(ins, scratch, output);
+  } else if (mirType == MIRType::BigInt) {
+    MOZ_ASSERT(value->isGeneralReg());
+    masm.mov(value->toGeneralReg()->reg(), scratch);
+    emitFuzzilliHashBigInt(scratch, output);
+  } else if (mirType == MIRType::Double) {
+    MOZ_ASSERT(value->isFloatReg());
+    masm.moveDouble(value->toFloatReg()->reg(), scratchFloat);
+    masm.canonicalizeDoubleIfDeterministic(scratchFloat);
+    emitFuzzilliHashDouble(scratchFloat, scratch, output);
+  } else if (mirType == MIRType::Float32) {
+    MOZ_ASSERT(value->isFloatReg());
+    masm.convertFloat32ToDouble(value->toFloatReg()->reg(), scratchFloat);
+    masm.canonicalizeDoubleIfDeterministic(scratchFloat);
+    emitFuzzilliHashDouble(scratchFloat, scratch, output);
+  } else if (mirType == MIRType::Int32) {
+    MOZ_ASSERT(value->isGeneralReg());
+    masm.mov(value->toGeneralReg()->reg(), scratch);
+    masm.convertInt32ToDouble(scratch, scratchFloat);
+    emitFuzzilliHashDouble(scratchFloat, scratch, output);
+  } else if (mirType == MIRType::Null) {
+    MOZ_ASSERT(value->isBogus());
+    masm.move32(Imm32(1), scratch);
+    masm.convertInt32ToDouble(scratch, scratchFloat);
+    emitFuzzilliHashDouble(scratchFloat, scratch, output);
+  } else if (mirType == MIRType::Undefined) {
+    MOZ_ASSERT(value->isBogus());
+    masm.move32(Imm32(2), scratch);
+    masm.convertInt32ToDouble(scratch, scratchFloat);
+    emitFuzzilliHashDouble(scratchFloat, scratch, output);
+  } else if (mirType == MIRType::Boolean) {
+    MOZ_ASSERT(value->isGeneralReg());
+    masm.mov(value->toGeneralReg()->reg(), scratch);
+    masm.add32(Imm32(3), scratch);
+    masm.convertInt32ToDouble(scratch, scratchFloat);
+    emitFuzzilliHashDouble(scratchFloat, scratch, output);
+  } else {
+    MOZ_CRASH("unexpected type");
+  }
+}
+
+void CodeGenerator::visitFuzzilliHashStore(LFuzzilliHashStore* ins) {
+  const LAllocation* value = ins->value();
+  MOZ_ASSERT(ins->mir()->getOperand(0)->type() == MIRType::Int32);
+  MOZ_ASSERT(value->isGeneralReg());
+
+  Register scratchJSContext = ToRegister(ins->getTemp(0));
+  Register scratch = ToRegister(ins->getTemp(1));
+
+  masm.loadJSContext(scratchJSContext);
+
+  // stats
+  Address addrExecHashInputs(scratchJSContext,
+                             offsetof(JSContext, executionHashInputs));
+  masm.load32(addrExecHashInputs, scratch);
+  masm.add32(Imm32(1), scratch);
+  masm.store32(scratch, addrExecHashInputs);
+
+  Address addrExecHash(scratchJSContext, offsetof(JSContext, executionHash));
+  masm.load32(addrExecHash, scratch);
+  masm.add32(value->toGeneralReg()->reg(), scratch);
+  masm.rotateLeft(Imm32(1), scratch, scratch);
+  masm.store32(scratch, addrExecHash);
+}
+#endif
+
+static_assert(!std::is_polymorphic_v<CodeGenerator>,
+              "CodeGenerator should not have any virtual methods");
+
+}  // namespace jit
+}  // namespace js
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