--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp	Thu Feb 26 21:00:03 2015 +0100
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp	Fri Feb 27 19:52:48 2015 -0500
@@ -1,6 +1,5 @@
-
 /*
- * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2015, 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
@@ -233,15 +232,12 @@
                       young_gen->to_space()->is_empty();
     young_gen_empty = eden_empty && survivors_empty;
 
-    BarrierSet* bs = heap->barrier_set();
-    if (bs->is_a(BarrierSet::ModRef)) {
-      ModRefBarrierSet* modBS = (ModRefBarrierSet*)bs;
-      MemRegion old_mr = heap->old_gen()->reserved();
-      if (young_gen_empty) {
-        modBS->clear(MemRegion(old_mr.start(), old_mr.end()));
-      } else {
-        modBS->invalidate(MemRegion(old_mr.start(), old_mr.end()));
-      }
+    ModRefBarrierSet* modBS = barrier_set_cast<ModRefBarrierSet>(heap->barrier_set());
+    MemRegion old_mr = heap->old_gen()->reserved();
+    if (young_gen_empty) {
+      modBS->clear(MemRegion(old_mr.start(), old_mr.end()));
+    } else {
+      modBS->invalidate(MemRegion(old_mr.start(), old_mr.end()));
     }
 
     // Delete metaspaces for unloaded class loaders and clean up loader_data graph