src/share/vm/gc/g1/g1BlockOffsetTable.inline.hpp

rev 12504 : 8173764: G1 BOT wrongly assumes that objects must always begin at the start of G1BlockOffsetTablePart
Reviewed-by:
rev 12505 : [mq]: 8173764-rev-tschatzl

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.

@@ -106,11 +106,12 @@
 
 inline HeapWord* G1BlockOffsetTablePart::block_at_or_preceding(const void* addr,
                                                                bool has_max_index,
                                                                size_t max_index) const {
   assert(_object_can_span || _bot->offset_array(_bot->index_for(_space->bottom())) == 0,
-         "normal objects can't cross region boundaries");
+         "Object crossed region boundary, found offset %u instead of 0",
+         (uint) _bot->offset_array(_bot->index_for(_space->bottom())));
   size_t index = _bot->index_for(addr);
   // We must make sure that the offset table entry we use is valid.  If
   // "addr" is past the end, start at the last known one and go forward.
   if (has_max_index) {
     index = MIN2(index, max_index);