diff --git a/js/src/ion/IonFrames.cpp b/js/src/ion/IonFrames.cpp
index f31a8741465..223dd0dbb8a 100644
--- a/js/src/ion/IonFrames.cpp
+++ b/js/src/ion/IonFrames.cpp
@@ -122,10 +122,7 @@ IonFrameIterator::isDOMExit() const
 {
     if (type_ != IonFrame_Exit)
         return false;
-    IonCode *code = exitFrame()->footer()->ionCode();
-    return code == ION_FRAME_DOMGETTER ||
-           code == ION_FRAME_DOMSETTER ||
-           code == ION_FRAME_DOMMETHOD;
+    return exitFrame()->isDomExit();
 }
 
 bool
diff --git a/js/src/ion/arm/IonFrames-arm.h b/js/src/ion/arm/IonFrames-arm.h
index 56bd6d2f7bd..f0cd1a5fb47 100644
--- a/js/src/ion/arm/IonFrames-arm.h
+++ b/js/src/ion/arm/IonFrames-arm.h
@@ -185,14 +185,28 @@ class IonExitFrameLayout : public IonCommonFrameLayout
         JS_ASSERT(footer()->ionCode() != NULL);
         return top();
     }
+
+    inline bool isWrapperExit() {
+        return footer()->function() != NULL;
+    }
+    inline bool isNativeExit() {
+        return footer()->ionCode() == NULL;
+    }
+    inline bool isDomExit() {
+        IonCode *code = footer()->ionCode();
+        return
+            code == ION_FRAME_DOMGETTER ||
+            code == ION_FRAME_DOMSETTER ||
+            code == ION_FRAME_DOMMETHOD;
+    }
+
     inline IonNativeExitFrameLayout *nativeExit() {
         // see CodeGenerator::visitCallNative
-        JS_ASSERT(footer()->ionCode() == NULL);
+        JS_ASSERT(isNativeExit());
         return reinterpret_cast<IonNativeExitFrameLayout *>(footer());
     }
     inline IonDOMExitFrameLayout *DOMExit() {
-        JS_ASSERT(footer()->ionCode() == ION_FRAME_DOMGETTER ||
-                  footer()->ionCode() == ION_FRAME_DOMSETTER);
+        JS_ASSERT(isDomExit());
         return reinterpret_cast<IonDOMExitFrameLayout *>(footer());
     }
 };
diff --git a/js/src/ion/shared/IonFrames-x86-shared.h b/js/src/ion/shared/IonFrames-x86-shared.h
index 00df2819f02..d543381b4f8 100644
--- a/js/src/ion/shared/IonFrames-x86-shared.h
+++ b/js/src/ion/shared/IonFrames-x86-shared.h
@@ -169,14 +169,28 @@ class IonExitFrameLayout : public IonCommonFrameLayout
         JS_ASSERT(footer()->ionCode() != NULL);
         return top();
     }
+
+    inline bool isWrapperExit() {
+        return footer()->function() != NULL;
+    }
+    inline bool isNativeExit() {
+        return footer()->ionCode() == NULL;
+    }
+    inline bool isDomExit() {
+        IonCode *code = footer()->ionCode();
+        return
+            code == ION_FRAME_DOMGETTER ||
+            code == ION_FRAME_DOMSETTER ||
+            code == ION_FRAME_DOMMETHOD;
+    }
+
     inline IonNativeExitFrameLayout *nativeExit() {
         // see CodeGenerator::visitCallNative
-        JS_ASSERT(footer()->ionCode() == NULL);
+        JS_ASSERT(isNativeExit());
         return reinterpret_cast<IonNativeExitFrameLayout *>(footer());
     }
     inline IonDOMExitFrameLayout *DOMExit() {
-        JS_ASSERT(footer()->ionCode() == ION_FRAME_DOMGETTER ||
-                  footer()->ionCode() == ION_FRAME_DOMSETTER);
+        JS_ASSERT(isDomExit());
         return reinterpret_cast<IonDOMExitFrameLayout *>(footer());
     }
 };