8033545: Missing volatile specifier in Bitmap::par_put_range_within_word
authortschatzl
Thu, 06 Feb 2014 17:12:10 +0100
changeset 22769 516e9b159656
parent 22768 363a44995a71
child 22770 0cbd539cce7a
8033545: Missing volatile specifier in Bitmap::par_put_range_within_word Summary: The method Bitmap::par_put_range_within_word reloads the original value during a CAS, which may be optimized away. Instead of reloading, use the value returned by Atomic::cmpxchg_ptr() for further processing. Reviewed-by: tschatzl, brutisso, tonyp Contributed-by: Matthias Braun <matthia.braun@sap.com>
hotspot/src/share/vm/utilities/bitMap.cpp
--- a/hotspot/src/share/vm/utilities/bitMap.cpp	Thu Feb 06 14:12:43 2014 +0100
+++ b/hotspot/src/share/vm/utilities/bitMap.cpp	Thu Feb 06 17:12:10 2014 +0100
@@ -107,7 +107,7 @@
     while (true) {
       intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
       if (res == w) break;
-      w  = *pw;
+      w  = res;
       nw = value ? (w | ~mr) : (w & mr);
     }
   }