# HG changeset patch
# User iveresov
# Date 1383218200 25200
# Node ID 946a8294ab15511a78463cb71a06d0b929f4e200
# Parent  4d3575d37a073f2ce386de56f13e98cf47056cf6
8024919: G1: SPECjbb2013 crashes due to a broken object reference
Summary: Pass correct new value to post_barrer() in Unsafe.getAndSetObject() C1 intrinsic
Reviewed-by: kvn, roland

diff -r 4d3575d37a07 -r 946a8294ab15 src/cpu/x86/vm/c1_LIRGenerator_x86.cpp
--- a/src/cpu/x86/vm/c1_LIRGenerator_x86.cpp	Wed Oct 30 22:55:11 2013 -0700
+++ b/src/cpu/x86/vm/c1_LIRGenerator_x86.cpp	Thu Oct 31 04:16:40 2013 -0700
@@ -1468,19 +1468,18 @@
     addr = new LIR_Address(src.result(), offset, type);
   }
 
-  if (data != dst) {
-    __ move(data, dst);
-    data = dst;
-  }
+  // Because we want a 2-arg form of xchg and xadd
+  __ move(data, dst);
+
   if (x->is_add()) {
-    __ xadd(LIR_OprFact::address(addr), data, dst, LIR_OprFact::illegalOpr);
+    __ xadd(LIR_OprFact::address(addr), dst, dst, LIR_OprFact::illegalOpr);
   } else {
     if (is_obj) {
       // Do the pre-write barrier, if any.
       pre_barrier(LIR_OprFact::address(addr), LIR_OprFact::illegalOpr /* pre_val */,
                   true /* do_load */, false /* patch */, NULL);
     }
-    __ xchg(LIR_OprFact::address(addr), data, dst, LIR_OprFact::illegalOpr);
+    __ xchg(LIR_OprFact::address(addr), dst, dst, LIR_OprFact::illegalOpr);
     if (is_obj) {
       // Seems to be a precise address
       post_barrier(LIR_OprFact::address(addr), data);