gimple-fold.c (fold_stmt_1): Check may_propagate_copy before valueizing return stmts.

2016-11-25  Richard Biener  <rguenther@suse.de>

	* gimple-fold.c (fold_stmt_1): Check may_propagate_copy
	before valueizing return stmts.

From-SVN: r242873

gcc/ChangeLog

+2016-11-25  Richard Biener  <rguenther@suse.de>
+
+	* gimple-fold.c (fold_stmt_1): Check may_propagate_copy
+	before valueizing return stmts.
+
 2016-11-24  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/78343

gcc/gimple-fold.c

@@ -4414,7 +4414,8 @@ fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace, tree (*valueize) (tree))
 	if (ret && TREE_CODE (ret) == SSA_NAME && valueize)
 	  {
 	    tree val = valueize (ret);
-	    if (val && val != ret)
+	    if (val && val != ret
+		&& may_propagate_copy (ret, val))
 	      {
 		gimple_return_set_retval (ret_stmt, val);
 		changed = true;