diff --git a/js/src/ion/CodeGenerator.cpp b/js/src/ion/CodeGenerator.cpp
index 7d9a5d1732e0..627f9e142659 100644
--- a/js/src/ion/CodeGenerator.cpp
+++ b/js/src/ion/CodeGenerator.cpp
@@ -3118,8 +3118,10 @@ 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, JSObject::getFixedSlotOffset(slot)), type, result);
 
-    masm.loadUnboxedValue(Address(obj, JSObject::getFixedSlotOffset(slot)), result);
     return true;
 }
 
diff --git a/js/src/ion/IonMacroAssembler.h b/js/src/ion/IonMacroAssembler.h
index 547de393401b..33a4c1a1e1ab 100644
--- a/js/src/ion/IonMacroAssembler.h
+++ b/js/src/ion/IonMacroAssembler.h
@@ -167,12 +167,8 @@ class MacroAssembler : public MacroAssemblerSpecific
     void loadTypedOrValue(const T &src, TypedOrValueRegister dest) {
         if (dest.hasValue())
             loadValue(src, dest.valueReg());
-        else if (dest.type() == MIRType_Int32)
-            unboxInt32(src, dest.typedReg().gpr());
-        else if (dest.type() == MIRType_Boolean)
-            unboxBoolean(src, dest.typedReg().gpr());
         else
-            loadUnboxedValue(src, dest.typedReg());
+            loadUnboxedValue(src, dest.type(), dest.typedReg());
     }
 
     template<typename T>
@@ -185,7 +181,7 @@ class MacroAssembler : public MacroAssemblerSpecific
         } else {
             if (holeCheck)
                 branchTestMagic(Assembler::Equal, src, hole);
-            loadUnboxedValue(src, dest.typedReg());
+            loadUnboxedValue(src, dest.type(), dest.typedReg());
         }
     }
 
diff --git a/js/src/ion/MIR.cpp b/js/src/ion/MIR.cpp
index 24c051757921..4b88b6ccff1b 100644
--- a/js/src/ion/MIR.cpp
+++ b/js/src/ion/MIR.cpp
@@ -41,7 +41,7 @@ MDefinition::earlyAbortCheck()
 {
     if (isPhi())
         return false;
-    for (int i = 0; i < numOperands(); i++) {
+    for (size_t i = 0; i < numOperands(); i++) {
         if (getOperand(i)->block()->earlyAbort()) {
             block()->setEarlyAbort();
             IonSpew(IonSpew_Range, "Ignoring value from block %d because instruction %d is in a block that aborts", block()->id(), getOperand(i)->id());
diff --git a/js/src/ion/arm/MacroAssembler-arm.h b/js/src/ion/arm/MacroAssembler-arm.h
index 0de0a1f4c84b..defabf078279 100644
--- a/js/src/ion/arm/MacroAssembler-arm.h
+++ b/js/src/ion/arm/MacroAssembler-arm.h
@@ -726,14 +726,14 @@ class MacroAssemblerARMCompat : public MacroAssemblerARM
         ma_b(label, cond);
     }
 
-    void loadUnboxedValue(Address address, AnyRegister dest) {
+    void loadUnboxedValue(Address address, MIRType type, AnyRegister dest) {
         if (dest.isFloat())
             loadInt32OrDouble(Operand(address), dest.fpu());
         else
             ma_ldr(address, dest.gpr());
     }
 
-    void loadUnboxedValue(BaseIndex address, AnyRegister dest) {
+    void loadUnboxedValue(BaseIndex address, MIRType type, AnyRegister dest) {
         if (dest.isFloat())
             loadInt32OrDouble(address.base, address.index, dest.fpu(), address.scale);
         else
diff --git a/js/src/ion/x64/MacroAssembler-x64.h b/js/src/ion/x64/MacroAssembler-x64.h
index 2be025e7a6ad..17be8f44a142 100644
--- a/js/src/ion/x64/MacroAssembler-x64.h
+++ b/js/src/ion/x64/MacroAssembler-x64.h
@@ -811,9 +811,11 @@ class MacroAssemblerX64 : public MacroAssemblerX86Shared
     }
 
     template <typename T>
-    void loadUnboxedValue(const T &src, AnyRegister dest) {
+    void loadUnboxedValue(const T &src, MIRType type, AnyRegister dest) {
         if (dest.isFloat())
             loadInt32OrDouble(Operand(src), dest.fpu());
+        else if (type == MIRType_Int32 || type == MIRType_Boolean)
+            movl(Operand(src), dest.gpr());
         else
             unboxNonDouble(Operand(src), dest.gpr());
     }
diff --git a/js/src/ion/x86/MacroAssembler-x86.h b/js/src/ion/x86/MacroAssembler-x86.h
index c45ba54f3314..b38b65128773 100644
--- a/js/src/ion/x86/MacroAssembler-x86.h
+++ b/js/src/ion/x86/MacroAssembler-x86.h
@@ -649,7 +649,7 @@ class MacroAssemblerX86 : public MacroAssemblerX86Shared
     }
 
     template <typename T>
-    void loadUnboxedValue(const T &src, AnyRegister dest) {
+    void loadUnboxedValue(const T &src, MIRType type, AnyRegister dest) {
         if (dest.isFloat())
             loadInt32OrDouble(Operand(src), dest.fpu());
         else