re PR rtl-optimization/63375 (reordering of reads across fences)

2014-10-02  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/63375
	* tree-sra.c (build_access_from_expr_1): Disqualify volatile
	references.

From-SVN: r215804

gcc/ChangeLog

+2014-10-02  Martin Jambor  <mjambor@suse.cz>
+
+	PR tree-optimization/63375
+	* tree-sra.c (build_access_from_expr_1): Disqualify volatile
+	references.
+
 2014-10-02  Olivier Hainque  <hainque@adacore.com>
 
 	* Makefile.in (CROSS): Define, to @CROSS.

gcc/tree-sra.c

@@ -1064,6 +1064,11 @@ build_access_from_expr_1 (tree expr, gimple stmt, bool write)
 			       "component.");
       return NULL;
     }
+  if (TREE_THIS_VOLATILE (expr))
+    {
+      disqualify_base_of_expr (expr, "part of a volatile reference.");
+      return NULL;
+    }
 
   switch (TREE_CODE (expr))
     {