--- a/src/share/vm/utilities/globalDefinitions.hpp	Thu Feb 13 17:57:27 2014 +0100
+++ b/src/share/vm/utilities/globalDefinitions.hpp	Wed Feb 19 12:08:49 2014 -0800
@@ -38,6 +38,9 @@
 #ifdef TARGET_COMPILER_sparcWorks
 # include "utilities/globalDefinitions_sparcWorks.hpp"
 #endif
+#ifdef TARGET_COMPILER_xlc
+# include "utilities/globalDefinitions_xlc.hpp"
+#endif
 
 #include "utilities/macros.hpp"
 
@@ -395,6 +398,17 @@
 #define PLATFORM_NATIVE_STACK_WALKING_SUPPORTED 1
 #endif
 
+// To assure the IRIW property on processors that are not multiple copy
+// atomic, sync instructions must be issued between volatile reads to
+// assure their ordering, instead of after volatile stores.
+// (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
+// by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
+#ifdef CPU_NOT_MULTIPLE_COPY_ATOMIC
+const bool support_IRIW_for_not_multiple_copy_atomic_cpu = true;
+#else
+const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
+#endif
+
 // The byte alignment to be used by Arena::Amalloc.  See bugid 4169348.
 // Note: this value must be a power of 2