fold-const.c (build_fold_addr_expr_with_type_loc): Fold MEM_REF with constant pointer operand.

2012-03-06  Richard Guenther  <rguenther@suse.de>

	* fold-const.c (build_fold_addr_expr_with_type_loc): Fold
	MEM_REF with constant pointer operand.

From-SVN: r184988

gcc/ChangeLog

 2012-03-06  Richard Guenther  <rguenther@suse.de>
 
+	* fold-const.c (build_fold_addr_expr_with_type_loc): Fold
+	MEM_REF with constant pointer operand.
+
+2012-03-06  Richard Guenther  <rguenther@suse.de>
+
 	PR middle-end/52493
 	* tree-ssa-alias.c (ptr_derefs_may_alias_p): Robustify.
 

gcc/fold-const.c

@@ -7626,8 +7626,13 @@ build_fold_addr_expr_with_type_loc (location_t loc, tree t, tree ptrtype)
 	t = build1_loc (loc, NOP_EXPR, ptrtype, t);
     }
   else if (TREE_CODE (t) == MEM_REF
-      && integer_zerop (TREE_OPERAND (t, 1)))
+	   && integer_zerop (TREE_OPERAND (t, 1)))
     return TREE_OPERAND (t, 0);
+  else if (TREE_CODE (t) == MEM_REF
+	   && TREE_CODE (TREE_OPERAND (t, 0)) == INTEGER_CST)
+    return fold_binary (POINTER_PLUS_EXPR, ptrtype,
+			TREE_OPERAND (t, 0),
+			convert_to_ptrofftype (TREE_OPERAND (t, 1)));
   else if (TREE_CODE (t) == VIEW_CONVERT_EXPR)
     {
       t = build_fold_addr_expr_loc (loc, TREE_OPERAND (t, 0));