--- old/src/share/vm/gc_implementation/parallelScavenge/objectStartArray.cpp	2015-02-13 13:27:24.028451177 -0800
+++ new/src/share/vm/gc_implementation/parallelScavenge/objectStartArray.cpp	2015-02-13 13:27:23.932451174 -0800
@@ -126,7 +126,9 @@
 
 bool ObjectStartArray::object_starts_in_range(HeapWord* start_addr,
                                               HeapWord* end_addr) const {
-  assert(start_addr <= end_addr, "range is wrong");
+  assert(start_addr <= end_addr,
+          err_msg("Range is wrong. start_addr (" PTR_FORMAT ") is after end_addr (" PTR_FORMAT ")",
+                 p2i(start_addr), p2i(end_addr)));
   if (start_addr > end_addr) {
     return false;
   }