diff --git a/include/avian/codegen/compiler.h b/include/avian/codegen/compiler.h
index 6e07a06d87..802601229d 100644
--- a/include/avian/codegen/compiler.h
+++ b/include/avian/codegen/compiler.h
@@ -140,7 +140,7 @@ class Compiler {
                            ir::Value* index,
                            intptr_t handler) = 0;
 
-  virtual ir::Value* truncateThenExtend(ir::SignExtendMode signExtend,
+  virtual ir::Value* truncateThenExtend(ir::ExtendMode extendMode,
                                         ir::Type extendType,
                                         ir::Type truncateType,
                                         ir::Value* src) = 0;
@@ -148,7 +148,7 @@ class Compiler {
   virtual ir::Value* truncate(ir::Type type, ir::Value* src) = 0;
 
   virtual void store(ir::Value* src, ir::Value* dst) = 0;
-  virtual ir::Value* load(ir::SignExtendMode signExtend,
+  virtual ir::Value* load(ir::ExtendMode extendMode,
                           ir::Value* src,
                           ir::Type dstType) = 0;
 
diff --git a/include/avian/codegen/ir.h b/include/avian/codegen/ir.h
index d694f0c154..8d35f9fe23 100644
--- a/include/avian/codegen/ir.h
+++ b/include/avian/codegen/ir.h
@@ -132,9 +132,9 @@ class Type {
   }
 };
 
-enum SignExtendMode { SignExtend, ZeroExtend };
+enum class ExtendMode { Signed, Unsigned };
 
-enum CallingConvention { NativeCallingConvention, AvianCallingConvention };
+enum class CallingConvention { Native, Avian };
 
 class Value {
  public:
diff --git a/src/codegen/compiler.cpp b/src/codegen/compiler.cpp
index cfa755dd83..36a4e5783a 100644
--- a/src/codegen/compiler.cpp
+++ b/src/codegen/compiler.cpp
@@ -2567,7 +2567,7 @@ class MyCompiler : public Compiler {
     Value* result = value(&c, resultType);
     appendCall(&c,
                static_cast<Value*>(address),
-               ir::NativeCallingConvention,
+               ir::CallingConvention::Native,
                flags,
                traceHandler,
                result,
@@ -2586,7 +2586,7 @@ class MyCompiler : public Compiler {
     Stack* b UNUSED = c.stack;
     appendCall(&c,
                static_cast<Value*>(address),
-               ir::AvianCallingConvention,
+               ir::CallingConvention::Avian,
                flags,
                traceHandler,
                result,
@@ -2741,14 +2741,14 @@ class MyCompiler : public Compiler {
     return dst;
   }
 
-  virtual ir::Value* truncateThenExtend(ir::SignExtendMode signExtend,
+  virtual ir::Value* truncateThenExtend(ir::ExtendMode extendMode,
                                         ir::Type extendType,
                                         ir::Type truncateType,
                                         ir::Value* src)
   {
     Value* dst = value(&c, extendType);
     appendMove(&c,
-               signExtend == ir::SignExtend ? lir::Move : lir::MoveZ,
+               extendMode == ir::ExtendMode::Signed ? lir::Move : lir::MoveZ,
                TargetBytesPerWord,
                truncateType.size(c.targetInfo),
                static_cast<Value*>(src),
@@ -2772,7 +2772,7 @@ class MyCompiler : public Compiler {
                static_cast<Value*>(dst));
   }
 
-  virtual ir::Value* load(ir::SignExtendMode signExtend,
+  virtual ir::Value* load(ir::ExtendMode extendMode,
                           ir::Value* src,
                           ir::Type dstType)
   {
@@ -2780,7 +2780,7 @@ class MyCompiler : public Compiler {
 
     Value* dst = value(&c, dstType);
     appendMove(&c,
-               signExtend == ir::SignExtend ? lir::Move : lir::MoveZ,
+               extendMode == ir::ExtendMode::Signed ? lir::Move : lir::MoveZ,
                src->type.size(c.targetInfo),
                src->type.size(c.targetInfo),
                static_cast<Value*>(src),
diff --git a/src/codegen/compiler/event.cpp b/src/codegen/compiler/event.cpp
index f59f5d124e..7bb0257f3f 100644
--- a/src/codegen/compiler/event.cpp
+++ b/src/codegen/compiler/event.cpp
@@ -368,13 +368,13 @@ class CallEvent : public Event {
         popIndex(0),
         stackArgumentIndex(0),
         flags(flags),
-        stackArgumentFootprint(callingConvention == ir::AvianCallingConvention
+        stackArgumentFootprint(callingConvention == ir::CallingConvention::Avian
                                    ? arguments.count
                                    : 0)
   {
     uint32_t registerMask = c->regFile->generalRegisters.mask;
 
-    if (callingConvention == ir::NativeCallingConvention) {
+    if (callingConvention == ir::CallingConvention::Native) {
       assertT(c, (flags & Compiler::TailJump) == 0);
       assertT(c, stackArgumentFootprint == 0);
 
@@ -450,7 +450,7 @@ class CallEvent : public Event {
 
     Stack* stack = stackBefore;
 
-    if (callingConvention == ir::AvianCallingConvention) {
+    if (callingConvention == ir::CallingConvention::Avian) {
       for (size_t i = 0; i < arguments.count; i++) {
         stack = stack->next;
       }
@@ -1257,7 +1257,7 @@ void appendCombine(Context* c,
 
     appendCall(c,
                value(c, ir::Type::addr(), constantSite(c, handler)),
-               ir::NativeCallingConvention,
+               ir::CallingConvention::Native,
                0,
                0,
                resultValue,
@@ -1413,7 +1413,7 @@ void appendTranslate(Context* c,
                                       op,
                                       firstValue->type.size(c->targetInfo),
                                       resultValue->type.size(c->targetInfo)))),
-               ir::NativeCallingConvention,
+               ir::CallingConvention::Native,
                0,
                0,
                resultValue,
@@ -1849,7 +1849,7 @@ void appendBranch(Context* c,
     Value* result = value(c, ir::Type::addr());
     appendCall(c,
                value(c, ir::Type::addr(), constantSite(c, handler)),
-               ir::NativeCallingConvention,
+               ir::CallingConvention::Native,
                0,
                0,
                result,
diff --git a/src/compile.cpp b/src/compile.cpp
index 1426d2a8c9..65a1417a72 100644
--- a/src/compile.cpp
+++ b/src/compile.cpp
@@ -3575,7 +3575,7 @@ ir::Value* popLongAddress(Frame* frame)
 {
   return TargetBytesPerWord == 8
              ? frame->popLarge(ir::Type::i8())
-             : frame->c->load(ir::SignExtend,
+             : frame->c->load(ir::ExtendMode::Signed,
                               frame->popLarge(ir::Type::i8()),
                               ir::Type::iptr());
 }
@@ -3616,7 +3616,7 @@ bool intrinsic(MyThread* t UNUSED, Frame* frame, GcMethod* target)
       ir::Value* address = popLongAddress(frame);
       frame->pop(ir::Type::object());
       frame->push(ir::Type::i4(),
-                  c->load(ir::SignExtend,
+                  c->load(ir::ExtendMode::Signed,
                           c->memory(address, ir::Type::i1()),
                           ir::Type::i4()));
       return true;
@@ -3634,7 +3634,7 @@ bool intrinsic(MyThread* t UNUSED, Frame* frame, GcMethod* target)
       ir::Value* address = popLongAddress(frame);
       frame->pop(ir::Type::object());
       frame->push(ir::Type::i4(),
-                  c->load(ir::SignExtend,
+                  c->load(ir::ExtendMode::Signed,
                           c->memory(address, ir::Type::i2()),
                           ir::Type::i4()));
       return true;
@@ -3656,7 +3656,7 @@ bool intrinsic(MyThread* t UNUSED, Frame* frame, GcMethod* target)
       ir::Type type = MATCH(target->name(), "getInt") ? ir::Type::i4()
                                                       : ir::Type::f4();
       frame->push(type,
-                  c->load(ir::SignExtend, c->memory(address, type), type));
+                  c->load(ir::ExtendMode::Signed, c->memory(address, type), type));
       return true;
     } else if ((MATCH(target->name(), "putInt")
                 and MATCH(target->spec(), "(JI)V"))
@@ -3678,7 +3678,7 @@ bool intrinsic(MyThread* t UNUSED, Frame* frame, GcMethod* target)
       ir::Type type = MATCH(target->name(), "getLong") ? ir::Type::i8()
                                                        : ir::Type::f8();
       frame->pushLarge(type,
-                       c->load(ir::SignExtend, c->memory(address, type), type));
+                       c->load(ir::ExtendMode::Signed, c->memory(address, type), type));
       return true;
     } else if ((MATCH(target->name(), "putLong")
                 and MATCH(target->spec(), "(JJ)V"))
@@ -3696,7 +3696,7 @@ bool intrinsic(MyThread* t UNUSED, Frame* frame, GcMethod* target)
       ir::Value* address = popLongAddress(frame);
       frame->pop(ir::Type::object());
       frame->pushLarge(ir::Type::i8(),
-                       c->load(ir::SignExtend,
+                       c->load(ir::ExtendMode::Signed,
                                c->memory(address, ir::Type::iptr()),
                                ir::Type::i8()));
       return true;
@@ -3976,7 +3976,7 @@ loop:
         frame->push(
             ir::Type::object(),
             c->load(
-                ir::SignExtend,
+                ir::ExtendMode::Signed,
                 c->memory(array, ir::Type::object(), TargetArrayBody, index),
                 ir::Type::object()));
         break;
@@ -3984,7 +3984,7 @@ loop:
       case faload:
         frame->push(
             ir::Type::f4(),
-            c->load(ir::SignExtend,
+            c->load(ir::ExtendMode::Signed,
                     c->memory(array, ir::Type::f4(), TargetArrayBody, index),
                     ir::Type::f4()));
         break;
@@ -3992,7 +3992,7 @@ loop:
       case iaload:
         frame->push(
             ir::Type::i4(),
-            c->load(ir::SignExtend,
+            c->load(ir::ExtendMode::Signed,
                     c->memory(array, ir::Type::i4(), TargetArrayBody, index),
                     ir::Type::i4()));
         break;
@@ -4000,7 +4000,7 @@ loop:
       case baload:
         frame->push(
             ir::Type::i4(),
-            c->load(ir::SignExtend,
+            c->load(ir::ExtendMode::Signed,
                     c->memory(array, ir::Type::i1(), TargetArrayBody, index),
                     ir::Type::i4()));
         break;
@@ -4008,7 +4008,7 @@ loop:
       case caload:
         frame->push(
             ir::Type::i4(),
-            c->load(ir::ZeroExtend,
+            c->load(ir::ExtendMode::Unsigned,
                     c->memory(array, ir::Type::i2(), TargetArrayBody, index),
                     ir::Type::i4()));
         break;
@@ -4016,7 +4016,7 @@ loop:
       case daload:
         frame->pushLarge(
             ir::Type::f8(),
-            c->load(ir::SignExtend,
+            c->load(ir::ExtendMode::Signed,
                     c->memory(array, ir::Type::f8(), TargetArrayBody, index),
                     ir::Type::f8()));
         break;
@@ -4024,7 +4024,7 @@ loop:
       case laload:
         frame->pushLarge(
             ir::Type::i8(),
-            c->load(ir::SignExtend,
+            c->load(ir::ExtendMode::Signed,
                     c->memory(array, ir::Type::i8(), TargetArrayBody, index),
                     ir::Type::i8()));
         break;
@@ -4032,7 +4032,7 @@ loop:
       case saload:
         frame->push(
             ir::Type::i4(),
-            c->load(ir::SignExtend,
+            c->load(ir::ExtendMode::Signed,
                     c->memory(array, ir::Type::i2(), TargetArrayBody, index),
                     ir::Type::i4()));
         break;
@@ -4190,7 +4190,7 @@ loop:
 
     case arraylength: {
       frame->push(ir::Type::i4(),
-                  c->load(ir::SignExtend,
+                  c->load(ir::ExtendMode::Signed,
                           c->memory(frame->pop(ir::Type::object()),
                                     ir::Type::iptr(),
                                     TargetArrayLength),
@@ -4509,7 +4509,7 @@ loop:
         case ByteField:
         case BooleanField:
           frame->push(ir::Type::i4(),
-                      c->load(ir::SignExtend,
+                      c->load(ir::ExtendMode::Signed,
                               c->memory(table,
                                         ir::Type::i1(),
                                         targetFieldOffset(context, field)),
@@ -4518,7 +4518,7 @@ loop:
 
         case CharField:
           frame->push(ir::Type::i4(),
-                      c->load(ir::ZeroExtend,
+                      c->load(ir::ExtendMode::Unsigned,
                               c->memory(table,
                                         ir::Type::i2(),
                                         targetFieldOffset(context, field)),
@@ -4527,7 +4527,7 @@ loop:
 
         case ShortField:
           frame->push(ir::Type::i4(),
-                      c->load(ir::SignExtend,
+                      c->load(ir::ExtendMode::Signed,
                               c->memory(table,
                                         ir::Type::i2(),
                                         targetFieldOffset(context, field)),
@@ -4536,7 +4536,7 @@ loop:
 
         case FloatField:
           frame->push(ir::Type::f4(),
-                      c->load(ir::SignExtend,
+                      c->load(ir::ExtendMode::Signed,
                               c->memory(table,
                                         ir::Type::f4(),
                                         targetFieldOffset(context, field)),
@@ -4545,7 +4545,7 @@ loop:
 
         case IntField:
           frame->push(ir::Type::i4(),
-                      c->load(ir::SignExtend,
+                      c->load(ir::ExtendMode::Signed,
                               c->memory(table,
                                         ir::Type::i4(),
                                         targetFieldOffset(context, field)),
@@ -4554,7 +4554,7 @@ loop:
 
         case DoubleField:
           frame->pushLarge(ir::Type::f8(),
-                           c->load(ir::SignExtend,
+                           c->load(ir::ExtendMode::Signed,
                                    c->memory(table,
                                              ir::Type::f8(),
                                              targetFieldOffset(context, field)),
@@ -4563,7 +4563,7 @@ loop:
 
         case LongField:
           frame->pushLarge(ir::Type::i8(),
-                           c->load(ir::SignExtend,
+                           c->load(ir::ExtendMode::Signed,
                                    c->memory(table,
                                              ir::Type::i8(),
                                              targetFieldOffset(context, field)),
@@ -4572,7 +4572,7 @@ loop:
 
         case ObjectField:
           frame->push(ir::Type::object(),
-                      c->load(ir::SignExtend,
+                      c->load(ir::ExtendMode::Signed,
                               c->memory(table,
                                         ir::Type::object(),
                                         targetFieldOffset(context, field)),
@@ -4662,7 +4662,7 @@ loop:
 
     case i2b: {
       frame->push(ir::Type::i4(),
-                  c->truncateThenExtend(ir::SignExtend,
+                  c->truncateThenExtend(ir::ExtendMode::Signed,
                                         ir::Type::i4(),
                                         ir::Type::i1(),
                                         frame->pop(ir::Type::i4())));
@@ -4670,7 +4670,7 @@ loop:
 
     case i2c: {
       frame->push(ir::Type::i4(),
-                  c->truncateThenExtend(ir::ZeroExtend,
+                  c->truncateThenExtend(ir::ExtendMode::Unsigned,
                                         ir::Type::i4(),
                                         ir::Type::i2(),
                                         frame->pop(ir::Type::i4())));
@@ -4688,7 +4688,7 @@ loop:
 
     case i2l:
       frame->pushLarge(ir::Type::i8(),
-                       c->truncateThenExtend(ir::SignExtend,
+                       c->truncateThenExtend(ir::ExtendMode::Signed,
                                              ir::Type::i8(),
                                              ir::Type::i4(),
                                              frame->pop(ir::Type::i4())));
@@ -4696,7 +4696,7 @@ loop:
 
     case i2s: {
       frame->push(ir::Type::i4(),
-                  c->truncateThenExtend(ir::SignExtend,
+                  c->truncateThenExtend(ir::ExtendMode::Signed,
                                         ir::Type::i4(),
                                         ir::Type::i2(),
                                         frame->pop(ir::Type::i4())));
@@ -6113,7 +6113,7 @@ next:
                                  0,
                                  normalizedKey);
 
-    c->jmp(c->load(ir::SignExtend,
+    c->jmp(c->load(ir::ExtendMode::Signed,
                    context->bootContext
                        ? c->binaryOp(lir::Add,
                                      ir::Type::iptr(),