--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/opto/JVMState.java	Wed Jan 08 12:05:19 2014 +0100
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/opto/JVMState.java	Wed Jan 08 10:25:50 2014 -0800
@@ -88,6 +88,10 @@
     return (int)bciField.getValue(getAddress());
   }
 
+  public int depth() {
+    return (int)depthField.getValue(getAddress());
+  }
+
   public JVMState caller() {
     return create(callerField.getValue(getAddress()));
   }