diff -r 3cfb240033d1 -r 3d2ab563047a src/share/vm/runtime/deoptimization.hpp
--- a/src/share/vm/runtime/deoptimization.hpp	Mon May 09 19:45:52 2011 -0700
+++ b/src/share/vm/runtime/deoptimization.hpp	Thu May 12 10:29:02 2011 -0700
@@ -138,6 +138,9 @@
     intptr_t* _register_block;            // Block for storing callee-saved registers.
     BasicType _return_type;               // Tells if we have to restore double or long return value
     intptr_t  _initial_fp;                // FP of the sender frame
+    int       _caller_actual_parameters;  // The number of actual arguments at the
+                                          // interpreted caller of the deoptimized frame
+
     // The following fields are used as temps during the unpacking phase
     // (which is tight on registers, especially on x86). They really ought
     // to be PD variables but that involves moving this class into its own
@@ -149,6 +152,7 @@
     // Constructor
     UnrollBlock(int  size_of_deoptimized_frame,
                 int  caller_adjustment,
+                int  caller_actual_parameters,
                 int  number_of_frames,
                 intptr_t* frame_sizes,
                 address* frames_pcs,
@@ -168,6 +172,8 @@
 
     void set_initial_fp(intptr_t fp) { _initial_fp = fp; }
 
+    int caller_actual_parameters() const { return _caller_actual_parameters; }
+
     // Accessors used by the code generator for the unpack stub.
     static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
     static int caller_adjustment_offset_in_bytes()         { return offset_of(UnrollBlock, _caller_adjustment);         }