--- old/src/share/vm/runtime/frame.hpp	Mon Jan 16 16:33:51 2012
+++ new/src/share/vm/runtime/frame.hpp	Mon Jan 16 16:33:50 2012
@@ -221,6 +221,15 @@
   // returns the stack pointer of the calling frame
   intptr_t* sender_sp() const;
 
+  // Returns the real 'frame pointer' for the current frame. 
+  // This is the value expected by the platform ABI when it defines a
+  // frame pointer register. It may differ from the effective value of
+  // the FP register when that register is used in the JVM for other
+  // purposes (like compiled frames on some platforms).
+  // On other platforms, it is defined so that the stack area used by
+  // this frame goes from real_fp() to sp().
+  intptr_t* real_fp() const;
+
   // Deoptimization info, if needed (platform dependent).
   // Stored in the initial_info field of the unroll info, to be used by
   // the platform dependent deoptimization blobs.