--- old/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp	2012-11-20 16:31:42.503894741 -0800
+++ new/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp	2012-11-20 16:31:42.284246517 -0800
@@ -49,16 +49,17 @@
   char* pc = (char*)p;
   assert(pc >= (char*)_reserved.start() &&
          pc <  (char*)_reserved.end(),
-         "p not in range.");
+         err_msg("p ("PTR_FORMAT") not in reserved ["PTR_FORMAT", "PTR_FORMAT")",
+                 p, (char*)_reserved.start(), (char*)_reserved.end()));
   size_t delta = pointer_delta(pc, _reserved.start(), sizeof(char));
   size_t result = delta >> LogN;
-  assert(result < _vs.committed_size(), "bad index from address");
+  check_index(result, "bad index from address");
   return result;
 }
 
 inline HeapWord*
 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
-  assert(index < _vs.committed_size(), "bad index");
+  check_index(index, "index out of range");
   HeapWord* result = _reserved.start() + (index << LogN_words);
   assert(result >= _reserved.start() && result < _reserved.end(),
          err_msg("bad address from index result " PTR_FORMAT