8014911: Should use SUPPORTS_NATIVE_CX8 define to help C/C++ compiler elide blocks of code
Summary: If SUPPORTS_NATIVE_CX8 true then supports_cx8() function hard coded to return 'true'
Reviewed-by: kvn, twisti, dholmes
--- a/hotspot/src/share/vm/runtime/vm_version.hpp Fri Sep 13 21:36:27 2013 -0400
+++ b/hotspot/src/share/vm/runtime/vm_version.hpp Fri Sep 20 15:06:23 2013 -0400
@@ -78,7 +78,13 @@
static const char* jre_release_version();
// does HW support an 8-byte compare-exchange operation?
- static bool supports_cx8() {return _supports_cx8;}
+ static bool supports_cx8() {
+#ifdef SUPPORTS_NATIVE_CX8
+ return true;
+#else
+ return _supports_cx8;
+#endif
+ }
// does HW support atomic get-and-set or atomic get-and-add? Used
// to guide intrinsification decisions for Unsafe atomic ops
static bool supports_atomic_getset4() {return _supports_atomic_getset4;}