src/share/vm/gc/g1/heapRegion.cpp

rev 12504 : 8173764: G1 BOT wrongly assumes that objects must always begin at the start of G1BlockOffsetTablePart
Reviewed-by:
rev 12505 : imported patch 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.

@@ -265,17 +265,21 @@
   assert(first_hr->is_starts_humongous(), "pre-condition");
 
   report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous);
   _type.set_continues_humongous();
   _humongous_start_region = first_hr;
+
+  _bot_part.set_object_can_span(true);
 }
 
 void HeapRegion::clear_humongous() {
   assert(is_humongous(), "pre-condition");
 
   assert(capacity() == HeapRegion::GrainBytes, "pre-condition");
   _humongous_start_region = NULL;
+
+  _bot_part.set_object_can_span(false);
 }
 
 HeapRegion::HeapRegion(uint hrm_index,
                        G1BlockOffsetTable* bot,
                        MemRegion mr) :