sparc.c (sparc_emit_membar_for_model): Add the implied StoreLoad barrier for…

sparc.c (sparc_emit_membar_for_model): Add the implied StoreLoad barrier for atomic operations if before.

	* config/sparc/sparc.c (sparc_emit_membar_for_model) <SMM_TSO>: Add
	the implied StoreLoad barrier for atomic operations if before.

From-SVN: r201450

gcc/ChangeLog

+2013-08-02  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* config/sparc/sparc.c (sparc_emit_membar_for_model) <SMM_TSO>: Add
+	the implied StoreLoad barrier for atomic operations if before.
+
 2013-08-02  Jan Hubicka  <jh@suse.cz>
 	    Martin Liska  <marxin.liska@gmail.com>
 

gcc/config/sparc/sparc.c

@@ -11318,6 +11318,11 @@ sparc_emit_membar_for_model (enum memmodel model,
       /* Total Store Ordering: all memory transactions with store semantics
 	 are followed by an implied StoreStore.  */
       implied |= StoreStore;
+
+      /* If we're not looking for a raw barrer (before+after), then atomic
+	 operations get the benefit of being both load and store.  */
+      if (load_store == 3 && before_after == 1)
+	implied |= StoreLoad;
       /* FALLTHRU */
 
     case SMM_PSO: