--- old/src/share/vm/oops/klass.cpp	2016-01-22 15:20:59.078776137 +0100
+++ new/src/share/vm/oops/klass.cpp	2016-01-22 15:20:58.978772021 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -659,6 +659,10 @@
   guarantee(obj->klass()->is_klass(), "klass field is not a klass");
 }
 
+ByteSize Klass::vtable_start_offset() {
+  return in_ByteSize(InstanceKlass::header_size() * wordSize);
+}
+
 #ifndef PRODUCT
 
 bool Klass::verify_vtable_index(int i) {