--- a/js/src/jit/CodeGenerator.cpp
+++ b/js/src/jit/CodeGenerator.cpp
@@ -3787,16 +3787,46 @@ void
 CodeGenerator::visitCopyLexicalEnvironmentObject(LCopyLexicalEnvironmentObject* lir)
 {
     pushArg(Imm32(lir->mir()->copySlots()));
     pushArg(ToRegister(lir->env()));
     callVM(CopyLexicalEnvironmentObjectInfo, lir);
 }
 
 void
+CodeGenerator::visitGuardShape(LGuardShape* guard)
+{
+    Register obj = ToRegister(guard->input());
+    Label bail;
+    masm.branchTestObjShape(Assembler::NotEqual, obj, guard->mir()->shape(), &bail);
+    bailoutFrom(&bail, guard->snapshot());
+}
+
+void
+CodeGenerator::visitGuardObjectGroup(LGuardObjectGroup* guard)
+{
+    Register obj = ToRegister(guard->input());
+    Assembler::Condition cond =
+        guard->mir()->bailOnEquality() ? Assembler::Equal : Assembler::NotEqual;
+    Label bail;
+    masm.branchTestObjGroup(cond, obj, guard->mir()->group(), &bail);
+    bailoutFrom(&bail, guard->snapshot());
+}
+
+void
+CodeGenerator::visitGuardClass(LGuardClass* guard)
+{
+    Register obj = ToRegister(guard->input());
+    Register tmp = ToRegister(guard->tempInt());
+    Label bail;
+    masm.branchTestObjClass(Assembler::NotEqual, obj, tmp, guard->mir()->getClass(), &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());

--- a/js/src/jit/CodeGenerator.h
+++ b/js/src/jit/CodeGenerator.h
@@ -150,16 +150,19 @@ class CodeGenerator final : public CodeG
     void visitLoadSlotT(LLoadSlotT* lir);
     void visitLoadSlotV(LLoadSlotV* lir);
     void visitStoreSlotT(LStoreSlotT* lir);
     void visitStoreSlotV(LStoreSlotV* lir);
     void visitElements(LElements* lir);
     void visitConvertElementsToDoubles(LConvertElementsToDoubles* lir);
     void visitMaybeToDoubleElement(LMaybeToDoubleElement* lir);
     void visitMaybeCopyElementsForWrite(LMaybeCopyElementsForWrite* lir);
+    void visitGuardShape(LGuardShape* guard);
+    void visitGuardObjectGroup(LGuardObjectGroup* guard);
+    void visitGuardClass(LGuardClass* guard);
     void visitGuardObjectIdentity(LGuardObjectIdentity* guard);
     void visitGuardReceiverPolymorphic(LGuardReceiverPolymorphic* lir);
     void visitGuardUnboxedExpando(LGuardUnboxedExpando* lir);
     void visitLoadUnboxedExpando(LLoadUnboxedExpando* lir);
     void visitTypeBarrierV(LTypeBarrierV* lir);
     void visitTypeBarrierO(LTypeBarrierO* lir);
     void emitPostWriteBarrier(const LAllocation* obj);
     void emitPostWriteBarrier(Register objreg);

--- a/js/src/jit/Lowering.cpp
+++ b/js/src/jit/Lowering.cpp
@@ -3993,20 +3993,41 @@ LIRGenerator::visitGuardObjectIdentity(M
     LGuardObjectIdentity* guard = new(alloc()) LGuardObjectIdentity(useRegister(ins->object()),
                                                                     useRegister(ins->expected()));
     assignSnapshot(guard, Bailout_ObjectIdentityOrTypeGuard);
     add(guard, ins);
     redefine(ins, ins->object());
 }
 
 void
+LIRGenerator::visitGuardShape(MGuardShape* ins)
+{
+    MOZ_ASSERT(ins->object()->type() == MIRType::Object);
+
+    LGuardShape* guard = new(alloc()) LGuardShape(useRegisterAtStart(ins->object()));
+    assignSnapshot(guard, ins->bailoutKind());
+    add(guard, ins);
+    redefine(ins, ins->object());
+}
+
+void
+LIRGenerator::visitGuardObjectGroup(MGuardObjectGroup* ins)
+{
+    MOZ_ASSERT(ins->object()->type() == MIRType::Object);
+
+    LGuardObjectGroup* guard = new(alloc()) LGuardObjectGroup(useRegisterAtStart(ins->object()));
+    assignSnapshot(guard, ins->bailoutKind());
+    add(guard, ins);
+    redefine(ins, ins->object());
+}
+
+void
 LIRGenerator::visitGuardClass(MGuardClass* ins)
 {
-    LDefinition t = temp();
-    LGuardClass* guard = new(alloc()) LGuardClass(useRegister(ins->object()), t);
+    LGuardClass* guard = new(alloc()) LGuardClass(useRegister(ins->object()), temp());
     assignSnapshot(guard, Bailout_ObjectIdentityOrTypeGuard);
     add(guard, ins);
 }
 
 void
 LIRGenerator::visitGuardObject(MGuardObject* ins)
 {
     // The type policy does all the work, so at this point the input

--- a/js/src/jit/Lowering.h
+++ b/js/src/jit/Lowering.h
@@ -259,16 +259,18 @@ class LIRGenerator : public LIRGenerator
     void visitStoreFixedSlot(MStoreFixedSlot* ins) override;
     void visitGetPropSuperCache(MGetPropSuperCache* ins) override;
     void visitGetPropertyCache(MGetPropertyCache* ins) override;
     void visitGetPropertyPolymorphic(MGetPropertyPolymorphic* ins) override;
     void visitSetPropertyPolymorphic(MSetPropertyPolymorphic* ins) override;
     void visitBindNameCache(MBindNameCache* ins) override;
     void visitCallBindVar(MCallBindVar* ins) override;
     void visitGuardObjectIdentity(MGuardObjectIdentity* ins) override;
+    void visitGuardShape(MGuardShape* ins) override;
+    void visitGuardObjectGroup(MGuardObjectGroup* ins) override;
     void visitGuardClass(MGuardClass* ins) override;
     void visitGuardObject(MGuardObject* ins) override;
     void visitGuardString(MGuardString* ins) override;
     void visitGuardReceiverPolymorphic(MGuardReceiverPolymorphic* ins) override;
     void visitGuardUnboxedExpando(MGuardUnboxedExpando* ins) override;
     void visitLoadUnboxedExpando(MLoadUnboxedExpando* ins) override;
     void visitPolyInlineGuard(MPolyInlineGuard* ins) override;
     void visitAssertRange(MAssertRange* ins) override;

--- a/js/src/jit/arm/CodeGenerator-arm.cpp
+++ b/js/src/jit/arm/CodeGenerator-arm.cpp
@@ -1738,46 +1738,16 @@ CodeGeneratorARM::visitNotF(LNotF* ins)
         masm.as_vmrs(pc);
         masm.ma_mov(Imm32(0), dest);
         masm.ma_mov(Imm32(1), dest, Assembler::Equal);
         masm.ma_mov(Imm32(1), dest, Assembler::Overflow);
     }
 }
 
 void
-CodeGeneratorARM::visitGuardShape(LGuardShape* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Label bail;
-    masm.branchTestObjShape(Assembler::NotEqual, obj, guard->mir()->shape(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
-CodeGeneratorARM::visitGuardObjectGroup(LGuardObjectGroup* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Assembler::Condition cond =
-        guard->mir()->bailOnEquality() ? Assembler::Equal : Assembler::NotEqual;
-    Label bail;
-    masm.branchTestObjGroup(cond, obj, guard->mir()->group(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
-CodeGeneratorARM::visitGuardClass(LGuardClass* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Register tmp = ToRegister(guard->tempInt());
-    Label bail;
-    masm.branchTestObjClass(Assembler::NotEqual, obj, tmp, guard->mir()->getClass(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
 CodeGeneratorARM::generateInvalidateEpilogue()
 {
     // Ensure that there is enough space in the buffer for the OsiPoint patching
     // to occur. Otherwise, we could overwrite the invalidation epilogue.
     for (size_t i = 0; i < sizeof(void*); i += Assembler::NopSize())
         masm.nop();
 
     masm.bind(&invalidate_);

--- a/js/src/jit/arm/CodeGenerator-arm.h
+++ b/js/src/jit/arm/CodeGenerator-arm.h
@@ -217,21 +217,16 @@ class CodeGeneratorARM : public CodeGene
 
   public:
     void visitBox(LBox* box);
     void visitBoxFloatingPoint(LBoxFloatingPoint* box);
     void visitUnbox(LUnbox* unbox);
     void visitValue(LValue* value);
     void visitDouble(LDouble* ins);
     void visitFloat32(LFloat32* ins);
-
-    void visitGuardShape(LGuardShape* guard);
-    void visitGuardObjectGroup(LGuardObjectGroup* guard);
-    void visitGuardClass(LGuardClass* guard);
-
     void visitNegI(LNegI* lir);
     void visitNegD(LNegD* lir);
     void visitNegF(LNegF* lir);
     void visitLoadTypedArrayElementStatic(LLoadTypedArrayElementStatic* ins);
     void visitStoreTypedArrayElementStatic(LStoreTypedArrayElementStatic* ins);
     void visitAtomicTypedArrayElementBinop(LAtomicTypedArrayElementBinop* lir);
     void visitAtomicTypedArrayElementBinopForEffect(LAtomicTypedArrayElementBinopForEffect* lir);
     void visitCompareExchangeTypedArrayElement(LCompareExchangeTypedArrayElement* lir);

--- a/js/src/jit/arm/LIR-arm.h
+++ b/js/src/jit/arm/LIR-arm.h
@@ -378,48 +378,16 @@ class LTableSwitchV : public LInstructio
     const LDefinition* tempFloat() {
         return getTemp(1);
     }
     const LDefinition* tempPointer() {
         return nullptr;
     }
 };
 
-class LGuardShape : public LInstructionHelper<0, 1, 0>
-{
-  public:
-    LIR_HEADER(GuardShape);
-
-    explicit LGuardShape(const LAllocation& in) {
-        setOperand(0, in);
-    }
-    const MGuardShape* mir() const {
-        return mir_->toGuardShape();
-    }
-    const LDefinition* tempInt() {
-        return getTemp(0);
-    }
-};
-
-class LGuardObjectGroup : public LInstructionHelper<0, 1, 0>
-{
-  public:
-    LIR_HEADER(GuardObjectGroup);
-
-    explicit LGuardObjectGroup(const LAllocation& in) {
-        setOperand(0, in);
-    }
-    const MGuardObjectGroup* mir() const {
-        return mir_->toGuardObjectGroup();
-    }
-    const LDefinition* tempInt() {
-        return getTemp(0);
-    }
-};
-
 class LMulI : public LBinaryMath<0>
 {
   public:
     LIR_HEADER(MulI);
 
     MMul* mir() {
         return mir_->toMul();
     }

--- a/js/src/jit/arm/Lowering-arm.cpp
+++ b/js/src/jit/arm/Lowering-arm.cpp
@@ -476,38 +476,16 @@ LIRGeneratorARM::newLTableSwitch(const L
 LTableSwitchV*
 LIRGeneratorARM::newLTableSwitchV(MTableSwitch* tableswitch)
 {
     return new(alloc()) LTableSwitchV(useBox(tableswitch->getOperand(0)),
                                       temp(), tempDouble(), tableswitch);
 }
 
 void
-LIRGeneratorARM::visitGuardShape(MGuardShape* ins)
-{
-    MOZ_ASSERT(ins->object()->type() == MIRType::Object);
-
-    LGuardShape* guard = new(alloc()) LGuardShape(useRegister(ins->object()));
-    assignSnapshot(guard, ins->bailoutKind());
-    add(guard, ins);
-    redefine(ins, ins->object());
-}
-
-void
-LIRGeneratorARM::visitGuardObjectGroup(MGuardObjectGroup* ins)
-{
-    MOZ_ASSERT(ins->object()->type() == MIRType::Object);
-
-    LGuardObjectGroup* guard = new(alloc()) LGuardObjectGroup(useRegister(ins->object()));
-    assignSnapshot(guard, ins->bailoutKind());
-    add(guard, ins);
-    redefine(ins, ins->object());
-}
-
-void
 LIRGeneratorARM::lowerUrshD(MUrsh* mir)
 {
     MDefinition* lhs = mir->lhs();
     MDefinition* rhs = mir->rhs();
 
     MOZ_ASSERT(lhs->type() == MIRType::Int32);
     MOZ_ASSERT(rhs->type() == MIRType::Int32);
 

--- a/js/src/jit/arm/Lowering-arm.h
+++ b/js/src/jit/arm/Lowering-arm.h
@@ -95,18 +95,16 @@ class LIRGeneratorARM : public LIRGenera
                                   MTableSwitch* ins);
     LTableSwitchV* newLTableSwitchV(MTableSwitch* ins);
 
   public:
     void visitBox(MBox* box) override;
     void visitUnbox(MUnbox* unbox) override;
     void visitReturn(MReturn* ret) override;
     void lowerPhi(MPhi* phi);
-    void visitGuardShape(MGuardShape* ins) override;
-    void visitGuardObjectGroup(MGuardObjectGroup* ins) override;
     void visitWasmSelect(MWasmSelect* ins) override;
     void visitWasmUnsignedToDouble(MWasmUnsignedToDouble* ins) override;
     void visitWasmUnsignedToFloat32(MWasmUnsignedToFloat32* ins) override;
     void visitWasmLoad(MWasmLoad* ins) override;
     void visitWasmStore(MWasmStore* ins) override;
     void visitAsmJSLoadHeap(MAsmJSLoadHeap* ins) override;
     void visitAsmJSStoreHeap(MAsmJSStoreHeap* ins) override;
     void visitWasmCompareExchangeHeap(MWasmCompareExchangeHeap* ins) override;

--- a/js/src/jit/arm64/CodeGenerator-arm64.cpp
+++ b/js/src/jit/arm64/CodeGenerator-arm64.cpp
@@ -572,34 +572,16 @@ void
 CodeGeneratorARM64::storeElementTyped(const LAllocation* value, MIRType valueType,
                                       MIRType elementType, Register elements,
                                       const LAllocation* index)
 {
     MOZ_CRASH("CodeGeneratorARM64::storeElementTyped");
 }
 
 void
-CodeGeneratorARM64::visitGuardShape(LGuardShape* guard)
-{
-    MOZ_CRASH("visitGuardShape");
-}
-
-void
-CodeGeneratorARM64::visitGuardObjectGroup(LGuardObjectGroup* guard)
-{
-    MOZ_CRASH("visitGuardObjectGroup");
-}
-
-void
-CodeGeneratorARM64::visitGuardClass(LGuardClass* guard)
-{
-    MOZ_CRASH("CodeGeneratorARM64::visitGuardClass");
-}
-
-void
 CodeGeneratorARM64::visitInterruptCheck(LInterruptCheck* lir)
 {
     MOZ_CRASH("CodeGeneratorARM64::visitInterruptCheck");
 }
 
 void
 CodeGeneratorARM64::generateInvalidateEpilogue()
 {

--- a/js/src/jit/arm64/CodeGenerator-arm64.h
+++ b/js/src/jit/arm64/CodeGenerator-arm64.h
@@ -179,20 +179,16 @@ class CodeGeneratorARM64 : public CodeGe
     void visitFloat32(LFloat32* ins);
 
     void visitLoadSlotV(LLoadSlotV* load);
     void visitLoadSlotT(LLoadSlotT* load);
     void visitStoreSlotT(LStoreSlotT* load);
 
     void visitLoadElementT(LLoadElementT* load);
 
-    void visitGuardShape(LGuardShape* guard);
-    void visitGuardObjectGroup(LGuardObjectGroup* guard);
-    void visitGuardClass(LGuardClass* guard);
-
     void visitInterruptCheck(LInterruptCheck* lir);
 
     void visitNegI(LNegI* lir);
     void visitNegD(LNegD* lir);
     void visitNegF(LNegF* lir);
     void visitLoadTypedArrayElementStatic(LLoadTypedArrayElementStatic* ins);
     void visitStoreTypedArrayElementStatic(LStoreTypedArrayElementStatic* ins);
     void visitCompareExchangeTypedArrayElement(LCompareExchangeTypedArrayElement* lir);

--- a/js/src/jit/arm64/LIR-arm64.h
+++ b/js/src/jit/arm64/LIR-arm64.h
@@ -303,50 +303,16 @@ class LTableSwitchV : public LInstructio
     const LDefinition* tempFloat() {
         return getTemp(1);
     }
     const LDefinition* tempPointer() {
         return nullptr;
     }
 };
 
-class LGuardShape : public LInstructionHelper<0, 1, 1>
-{
-  public:
-    LIR_HEADER(GuardShape);
-
-    LGuardShape(const LAllocation& in, const LDefinition& temp) {
-        setOperand(0, in);
-        setTemp(0, temp);
-    }
-    const MGuardShape* mir() const {
-        return mir_->toGuardShape();
-    }
-    const LDefinition* tempInt() {
-        return getTemp(0);
-    }
-};
-
-class LGuardObjectGroup : public LInstructionHelper<0, 1, 1>
-{
-  public:
-    LIR_HEADER(GuardObjectGroup);
-
-    LGuardObjectGroup(const LAllocation& in, const LDefinition& temp) {
-        setOperand(0, in);
-        setTemp(0, temp);
-    }
-    const MGuardObjectGroup* mir() const {
-        return mir_->toGuardObjectGroup();
-    }
-    const LDefinition* tempInt() {
-        return getTemp(0);
-    }
-};
-
 class LMulI : public LBinaryMath<0>
 {
   public:
     LIR_HEADER(MulI);
 
     MMul* mir() {
         return mir_->toMul();
     }

--- a/js/src/jit/arm64/Lowering-arm64.cpp
+++ b/js/src/jit/arm64/Lowering-arm64.cpp
@@ -193,28 +193,16 @@ LIRGeneratorARM64::newLTableSwitch(const
 
 LTableSwitchV*
 LIRGeneratorARM64::newLTableSwitchV(MTableSwitch* tableswitch)
 {
     MOZ_CRASH("newLTableSwitchV");
 }
 
 void
-LIRGeneratorARM64::visitGuardShape(MGuardShape* ins)
-{
-    MOZ_CRASH("visitGuardShape");
-}
-
-void
-LIRGeneratorARM64::visitGuardObjectGroup(MGuardObjectGroup* ins)
-{
-    MOZ_CRASH("visitGuardObjectGroup");
-}
-
-void
 LIRGeneratorARM64::lowerUrshD(MUrsh* mir)
 {
     MOZ_CRASH("lowerUrshD");
 }
 
 void
 LIRGeneratorARM64::visitWasmNeg(MWasmNeg* ins)
 {

--- a/js/src/jit/arm64/Lowering-arm64.h
+++ b/js/src/jit/arm64/Lowering-arm64.h
@@ -96,18 +96,16 @@ class LIRGeneratorARM64 : public LIRGene
                                   const LDefinition& inputCopy,
                                   MTableSwitch* ins);
 
   public:
     void visitBox(MBox* box) override;
     void visitUnbox(MUnbox* unbox) override;
     void visitReturn(MReturn* ret) override;
     void lowerPhi(MPhi* phi);
-    void visitGuardShape(MGuardShape* ins) override;
-    void visitGuardObjectGroup(MGuardObjectGroup* ins) override;
     void visitWasmUnsignedToDouble(MWasmUnsignedToDouble* ins) override;
     void visitWasmUnsignedToFloat32(MWasmUnsignedToFloat32* ins) override;
     void visitAsmJSLoadHeap(MAsmJSLoadHeap* ins) override;
     void visitAsmJSStoreHeap(MAsmJSStoreHeap* ins) override;
     void visitWasmCompareExchangeHeap(MWasmCompareExchangeHeap* ins) override;
     void visitWasmAtomicExchangeHeap(MWasmAtomicExchangeHeap* ins) override;
     void visitWasmAtomicBinopHeap(MWasmAtomicBinopHeap* ins) override;
     void visitStoreTypedArrayElementStatic(MStoreTypedArrayElementStatic* ins) override;

--- a/js/src/jit/mips-shared/CodeGenerator-mips-shared.cpp
+++ b/js/src/jit/mips-shared/CodeGenerator-mips-shared.cpp
@@ -1764,46 +1764,16 @@ CodeGeneratorMIPSShared::visitNotF(LNotF
     FloatRegister in = ToFloatRegister(ins->input());
     Register dest = ToRegister(ins->output());
 
     masm.loadConstantFloat32(0.0f, ScratchFloat32Reg);
     masm.ma_cmp_set_float32(dest, in, ScratchFloat32Reg, Assembler::DoubleEqualOrUnordered);
 }
 
 void
-CodeGeneratorMIPSShared::visitGuardShape(LGuardShape* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Label bail;
-    masm.branchTestObjShape(Assembler::NotEqual, obj, guard->mir()->shape(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
-CodeGeneratorMIPSShared::visitGuardObjectGroup(LGuardObjectGroup* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Assembler::Condition cond =
-        guard->mir()->bailOnEquality() ? Assembler::Equal : Assembler::NotEqual;
-    Label bail;
-    masm.branchTestObjGroup(cond, obj, guard->mir()->group(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
-CodeGeneratorMIPSShared::visitGuardClass(LGuardClass* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Register tmp = ToRegister(guard->tempInt());
-    Label bail;
-    masm.branchTestObjClass(Assembler::NotEqual, obj, tmp, guard->mir()->getClass(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
 CodeGeneratorMIPSShared::visitMemoryBarrier(LMemoryBarrier* ins)
 {
     masm.memoryBarrier(ins->type());
 }
 
 void
 CodeGeneratorMIPSShared::generateInvalidateEpilogue()
 {

--- a/js/src/jit/mips-shared/CodeGenerator-mips-shared.h
+++ b/js/src/jit/mips-shared/CodeGenerator-mips-shared.h
@@ -201,21 +201,16 @@ class CodeGeneratorMIPSShared : public C
     void visitCopySignF(LCopySignF* ins);
 
   public:
     CodeGeneratorMIPSShared(MIRGenerator* gen, LIRGraph* graph, MacroAssembler* masm);
 
     void visitValue(LValue* value);
     void visitDouble(LDouble* ins);
     void visitFloat32(LFloat32* ins);
-
-    void visitGuardShape(LGuardShape* guard);
-    void visitGuardObjectGroup(LGuardObjectGroup* guard);
-    void visitGuardClass(LGuardClass* guard);
-
     void visitNegI(LNegI* lir);
     void visitNegD(LNegD* lir);
     void visitNegF(LNegF* lir);
     void visitLoadTypedArrayElementStatic(LLoadTypedArrayElementStatic* ins);
     void visitStoreTypedArrayElementStatic(LStoreTypedArrayElementStatic* ins);
     void visitWasmLoad(LWasmLoad* ins);
     void visitWasmUnalignedLoad(LWasmUnalignedLoad* ins);
     void visitWasmStore(LWasmStore* ins);

--- a/js/src/jit/mips-shared/LIR-mips-shared.h
+++ b/js/src/jit/mips-shared/LIR-mips-shared.h
@@ -205,48 +205,16 @@ class LTableSwitchV : public LInstructio
     const LDefinition* tempFloat() {
         return getTemp(1);
     }
     const LDefinition* tempPointer() {
         return getTemp(2);
     }
 };
 
-class LGuardShape : public LInstructionHelper<0, 1, 0>
-{
-  public:
-    LIR_HEADER(GuardShape);
-
-    explicit LGuardShape(const LAllocation& in) {
-        setOperand(0, in);
-    }
-    const MGuardShape* mir() const {
-        return mir_->toGuardShape();
-    }
-    const LDefinition* tempInt() {
-        return getTemp(0);
-    }
-};
-
-class LGuardObjectGroup : public LInstructionHelper<0, 1, 0>
-{
-  public:
-    LIR_HEADER(GuardObjectGroup);
-
-    explicit LGuardObjectGroup(const LAllocation& in) {
-        setOperand(0, in);
-    }
-    const MGuardObjectGroup* mir() const {
-        return mir_->toGuardObjectGroup();
-    }
-    const LDefinition* tempInt() {
-        return getTemp(0);
-    }
-};
-
 class LMulI : public LBinaryMath<0>
 {
   public:
     LIR_HEADER(MulI);
 
     MMul* mir() {
         return mir_->toMul();
     }

--- a/js/src/jit/mips-shared/Lowering-mips-shared.cpp
+++ b/js/src/jit/mips-shared/Lowering-mips-shared.cpp
@@ -283,38 +283,16 @@ LIRGeneratorMIPSShared::newLTableSwitch(
 LTableSwitchV*
 LIRGeneratorMIPSShared::newLTableSwitchV(MTableSwitch* tableswitch)
 {
     return new(alloc()) LTableSwitchV(useBox(tableswitch->getOperand(0)),
                                       temp(), tempDouble(), temp(), tableswitch);
 }
 
 void
-LIRGeneratorMIPSShared::visitGuardShape(MGuardShape* ins)
-{
-    MOZ_ASSERT(ins->object()->type() == MIRType::Object);
-
-    LGuardShape* guard = new(alloc()) LGuardShape(useRegister(ins->object()));
-    assignSnapshot(guard, ins->bailoutKind());
-    add(guard, ins);
-    redefine(ins, ins->object());
-}
-
-void
-LIRGeneratorMIPSShared::visitGuardObjectGroup(MGuardObjectGroup* ins)
-{
-    MOZ_ASSERT(ins->object()->type() == MIRType::Object);
-
-    LGuardObjectGroup* guard = new(alloc()) LGuardObjectGroup(useRegister(ins->object()));
-    assignSnapshot(guard, ins->bailoutKind());
-    add(guard, ins);
-    redefine(ins, ins->object());
-}
-
-void
 LIRGeneratorMIPSShared::lowerUrshD(MUrsh* mir)
 {
     MDefinition* lhs = mir->lhs();
     MDefinition* rhs = mir->rhs();
 
     MOZ_ASSERT(lhs->type() == MIRType::Int32);
     MOZ_ASSERT(rhs->type() == MIRType::Int32);
 

--- a/js/src/jit/mips-shared/Lowering-mips-shared.h
+++ b/js/src/jit/mips-shared/Lowering-mips-shared.h
@@ -76,18 +76,16 @@ class LIRGeneratorMIPSShared : public LI
     void visitWasmSelect(MWasmSelect* ins);
 
     LTableSwitch* newLTableSwitch(const LAllocation& in, const LDefinition& inputCopy,
                                   MTableSwitch* ins);
     LTableSwitchV* newLTableSwitchV(MTableSwitch* ins);
 
   public:
     void lowerPhi(MPhi* phi);
-    void visitGuardShape(MGuardShape* ins);
-    void visitGuardObjectGroup(MGuardObjectGroup* ins);
     void visitWasmUnsignedToDouble(MWasmUnsignedToDouble* ins);
     void visitWasmUnsignedToFloat32(MWasmUnsignedToFloat32* ins);
     void visitAsmJSLoadHeap(MAsmJSLoadHeap* ins);
     void visitAsmJSStoreHeap(MAsmJSStoreHeap* ins);
     void visitWasmCompareExchangeHeap(MWasmCompareExchangeHeap* ins);
     void visitWasmAtomicExchangeHeap(MWasmAtomicExchangeHeap* ins);
     void visitWasmAtomicBinopHeap(MWasmAtomicBinopHeap* ins);
     void visitStoreTypedArrayElementStatic(MStoreTypedArrayElementStatic* ins);

--- a/js/src/jit/none/LIR-none.h
+++ b/js/src/jit/none/LIR-none.h
@@ -96,16 +96,14 @@ class LModPowTwoI : public LInstructionH
 {
 
   public:
     int32_t shift() { MOZ_CRASH(); }
     LModPowTwoI(const LAllocation& lhs, int32_t shift) { MOZ_CRASH(); }
     MMod* mir() const { MOZ_CRASH(); }
 };
 
-class LGuardShape : public LInstruction {};
-class LGuardObjectGroup : public LInstruction {};
 class LMulI : public LInstruction {};
 
 } // namespace jit
 } // namespace js
 
 #endif /* jit_none_LIR_none_h */

--- a/js/src/jit/none/Lowering-none.h
+++ b/js/src/jit/none/Lowering-none.h
@@ -70,18 +70,16 @@ class LIRGeneratorNone : public LIRGener
     void lowerMulI(MMul*, MDefinition*, MDefinition*) { MOZ_CRASH(); }
     void lowerUDiv(MDiv*) { MOZ_CRASH(); }
     void lowerUMod(MMod*) { MOZ_CRASH(); }
     void visitBox(MBox* box) override { MOZ_CRASH(); }
     void visitUnbox(MUnbox* unbox) override { MOZ_CRASH(); }
     void visitReturn(MReturn* ret) override { MOZ_CRASH(); }
     void visitPowHalf(MPowHalf*) override { MOZ_CRASH(); }
     void visitWasmNeg(MWasmNeg*) override { MOZ_CRASH(); }
-    void visitGuardShape(MGuardShape* ins) override { MOZ_CRASH(); }
-    void visitGuardObjectGroup(MGuardObjectGroup* ins) override { MOZ_CRASH(); }
     void visitWasmUnsignedToDouble(MWasmUnsignedToDouble* ins) override { MOZ_CRASH(); }
     void visitWasmUnsignedToFloat32(MWasmUnsignedToFloat32* ins) override { MOZ_CRASH(); }
     void visitAsmJSLoadHeap(MAsmJSLoadHeap* ins) override { MOZ_CRASH(); }
     void visitAsmJSStoreHeap(MAsmJSStoreHeap* ins) override { MOZ_CRASH(); }
     void visitStoreTypedArrayElementStatic(MStoreTypedArrayElementStatic* ins) override { MOZ_CRASH(); }
     void visitAtomicTypedArrayElementBinop(MAtomicTypedArrayElementBinop* ins) override { MOZ_CRASH(); }
     void visitCompareExchangeTypedArrayElement(MCompareExchangeTypedArrayElement* ins) override { MOZ_CRASH(); }
     void visitAtomicExchangeTypedArrayElement(MAtomicExchangeTypedArrayElement* ins) override { MOZ_CRASH(); }

--- a/js/src/jit/shared/LIR-shared.h
+++ b/js/src/jit/shared/LIR-shared.h
@@ -8036,16 +8036,42 @@ class LGuardObjectIdentity : public LIns
     const LAllocation* expected() {
         return getOperand(1);
     }
     const MGuardObjectIdentity* mir() const {
         return mir_->toGuardObjectIdentity();
     }
 };
 
+class LGuardShape : public LInstructionHelper<0, 1, 0>
+{
+  public:
+    LIR_HEADER(GuardShape)
+
+    explicit LGuardShape(const LAllocation& in) {
+        setOperand(0, in);
+    }
+    const MGuardShape* mir() const {
+        return mir_->toGuardShape();
+    }
+};
+
+class LGuardObjectGroup : public LInstructionHelper<0, 1, 0>
+{
+  public:
+    LIR_HEADER(GuardObjectGroup)
+
+    explicit LGuardObjectGroup(const LAllocation& in) {
+        setOperand(0, in);
+    }
+    const MGuardObjectGroup* mir() const {
+        return mir_->toGuardObjectGroup();
+    }
+};
+
 // Guard against an object's class.
 class LGuardClass : public LInstructionHelper<0, 1, 1>
 {
   public:
     LIR_HEADER(GuardClass)
 
     LGuardClass(const LAllocation& in, const LDefinition& temp) {
         setOperand(0, in);

--- a/js/src/jit/x86-shared/CodeGenerator-x86-shared.cpp
+++ b/js/src/jit/x86-shared/CodeGenerator-x86-shared.cpp
@@ -2368,46 +2368,16 @@ CodeGeneratorX86Shared::visitNearbyIntF(
     FloatRegister input = ToFloatRegister(lir->input());
     FloatRegister output = ToFloatRegister(lir->output());
 
     RoundingMode roundingMode = lir->mir()->roundingMode();
     masm.vroundss(Assembler::ToX86RoundingMode(roundingMode), input, output, output);
 }
 
 void
-CodeGeneratorX86Shared::visitGuardShape(LGuardShape* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Label bail;
-    masm.branchTestObjShape(Assembler::NotEqual, obj, guard->mir()->shape(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
-CodeGeneratorX86Shared::visitGuardObjectGroup(LGuardObjectGroup* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Assembler::Condition cond =
-        guard->mir()->bailOnEquality() ? Assembler::Equal : Assembler::NotEqual;
-    Label bail;
-    masm.branchTestObjGroup(cond, obj, guard->mir()->group(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
-CodeGeneratorX86Shared::visitGuardClass(LGuardClass* guard)
-{
-    Register obj = ToRegister(guard->input());
-    Register tmp = ToRegister(guard->tempInt());
-    Label bail;
-    masm.branchTestObjClass(Assembler::NotEqual, obj, tmp, guard->mir()->getClass(), &bail);
-    bailoutFrom(&bail, guard->snapshot());
-}
-
-void
 CodeGeneratorX86Shared::visitEffectiveAddress(LEffectiveAddress* ins)
 {
     const MEffectiveAddress* mir = ins->mir();
     Register base = ToRegister(ins->base());
     Register index = ToRegister(ins->index());
     Register output = ToRegister(ins->output());
     masm.leal(Operand(base, index, mir->scale(), mir->displacement()), output);
 }

--- a/js/src/jit/x86-shared/CodeGenerator-x86-shared.h
+++ b/js/src/jit/x86-shared/CodeGenerator-x86-shared.h
@@ -236,19 +236,16 @@ class CodeGeneratorX86Shared : public Co
     void visitFloor(LFloor* lir);
     void visitFloorF(LFloorF* lir);
     void visitCeil(LCeil* lir);
     void visitCeilF(LCeilF* lir);
     void visitRound(LRound* lir);
     void visitRoundF(LRoundF* lir);
     void visitNearbyInt(LNearbyInt* lir);
     void visitNearbyIntF(LNearbyIntF* lir);
-    void visitGuardShape(LGuardShape* guard);
-    void visitGuardObjectGroup(LGuardObjectGroup* guard);
-    void visitGuardClass(LGuardClass* guard);
     void visitEffectiveAddress(LEffectiveAddress* ins);
     void visitUDivOrMod(LUDivOrMod* ins);
     void visitUDivOrModConstant(LUDivOrModConstant *ins);
     void visitWasmStackArg(LWasmStackArg* ins);
     void visitWasmStackArgI64(LWasmStackArgI64* ins);
     void visitWasmSelect(LWasmSelect* ins);
     void visitWasmReinterpret(LWasmReinterpret* lir);
     void visitMemoryBarrier(LMemoryBarrier* ins);

--- a/js/src/jit/x86-shared/LIR-x86-shared.h
+++ b/js/src/jit/x86-shared/LIR-x86-shared.h
@@ -299,42 +299,16 @@ class LTableSwitchV : public LInstructio
     const LDefinition* tempFloat() {
         return getTemp(1);
     }
     const LDefinition* tempPointer() {
         return getTemp(2);
     }
 };
 
-class LGuardShape : public LInstructionHelper<0, 1, 0>
-{
-  public:
-    LIR_HEADER(GuardShape)
-
-    explicit LGuardShape(const LAllocation& in) {
-        setOperand(0, in);
-    }
-    const MGuardShape* mir() const {
-        return mir_->toGuardShape();
-    }
-};
-
-class LGuardObjectGroup : public LInstructionHelper<0, 1, 0>
-{
-  public:
-    LIR_HEADER(GuardObjectGroup)
-
-    explicit LGuardObjectGroup(const LAllocation& in) {
-        setOperand(0, in);
-    }
-    const MGuardObjectGroup* mir() const {
-        return mir_->toGuardObjectGroup();
-    }
-};
-
 class LMulI : public LBinaryMath<0, 1>
 {
   public:
     LIR_HEADER(MulI)
 
     LMulI(const LAllocation& lhs, const LAllocation& rhs, const LAllocation& lhsCopy) {
         setOperand(0, lhs);
         setOperand(1, rhs);

--- a/js/src/jit/x86-shared/Lowering-x86-shared.cpp
+++ b/js/src/jit/x86-shared/Lowering-x86-shared.cpp
@@ -29,38 +29,16 @@ LIRGeneratorX86Shared::newLTableSwitch(c
 LTableSwitchV*
 LIRGeneratorX86Shared::newLTableSwitchV(MTableSwitch* tableswitch)
 {
     return new(alloc()) LTableSwitchV(useBox(tableswitch->getOperand(0)),
                                       temp(), tempDouble(), temp(), tableswitch);
 }
 
 void
-LIRGeneratorX86Shared::visitGuardShape(MGuardShape* ins)
-{
-    MOZ_ASSERT(ins->object()->type() == MIRType::Object);
-
-    LGuardShape* guard = new(alloc()) LGuardShape(useRegisterAtStart(ins->object()));
-    assignSnapshot(guard, ins->bailoutKind());
-    add(guard, ins);
-    redefine(ins, ins->object());
-}
-
-void
-LIRGeneratorX86Shared::visitGuardObjectGroup(MGuardObjectGroup* ins)
-{
-    MOZ_ASSERT(ins->object()->type() == MIRType::Object);
-
-    LGuardObjectGroup* guard = new(alloc()) LGuardObjectGroup(useRegisterAtStart(ins->object()));
-    assignSnapshot(guard, ins->bailoutKind());
-    add(guard, ins);
-    redefine(ins, ins->object());
-}
-
-void
 LIRGeneratorX86Shared::visitPowHalf(MPowHalf* ins)
 {
     MDefinition* input = ins->input();
     MOZ_ASSERT(input->type() == MIRType::Double);
     LPowHalfD* lir = new(alloc()) LPowHalfD(useRegisterAtStart(input));
     define(lir, ins);
 }
 

--- a/js/src/jit/x86-shared/Lowering-x86-shared.h
+++ b/js/src/jit/x86-shared/Lowering-x86-shared.h
@@ -18,18 +18,16 @@ class LIRGeneratorX86Shared : public LIR
     LIRGeneratorX86Shared(MIRGenerator* gen, MIRGraph& graph, LIRGraph& lirGraph)
       : LIRGeneratorShared(gen, graph, lirGraph)
     {}
 
     LTableSwitch* newLTableSwitch(const LAllocation& in, const LDefinition& inputCopy,
                                   MTableSwitch* ins);
     LTableSwitchV* newLTableSwitchV(MTableSwitch* ins);
 
-    void visitGuardShape(MGuardShape* ins) override;
-    void visitGuardObjectGroup(MGuardObjectGroup* ins) override;
     void visitPowHalf(MPowHalf* ins) override;
     void lowerForShift(LInstructionHelper<1, 2, 0>* ins, MDefinition* mir, MDefinition* lhs,
                        MDefinition* rhs);
     void lowerForALU(LInstructionHelper<1, 1, 0>* ins, MDefinition* mir, MDefinition* input);
     void lowerForALU(LInstructionHelper<1, 2, 0>* ins, MDefinition* mir, MDefinition* lhs,
                      MDefinition* rhs);
 
     template<size_t Temps>