re PR rtl-optimization/45235 (const volatile read moved out of order)

2011-01-11  Richard Guenther  <rguenther@suse.de>

	PR middle-end/45235
	* emit-rtl.c (set_mem_attributes_minus_bitpos): Do not mark
	volatile MEMs as MEM_READONLY_P.

From-SVN: r168663

gcc/ChangeLog

 2011-01-11  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/45235
+	* emit-rtl.c (set_mem_attributes_minus_bitpos): Do not mark
+	volatile MEMs as MEM_READONLY_P.
+
+2011-01-11  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/47239
 	* tree-ssa-ccp.c (get_value_from_alignment): Punt for FUNCTION_DECLs.
 

gcc/emit-rtl.c

@@ -1698,7 +1698,8 @@ set_mem_attributes_minus_bitpos (rtx ref, tree t, int objectp,
       base = get_base_address (base);
       if (base && DECL_P (base)
 	  && TREE_READONLY (base)
-	  && (TREE_STATIC (base) || DECL_EXTERNAL (base)))
+	  && (TREE_STATIC (base) || DECL_EXTERNAL (base))
+	  && !TREE_THIS_VOLATILE (base))
 	MEM_READONLY_P (ref) = 1;
 
       /* If this expression uses it's parent's alias set, mark it such