+ if (val != 0) {
+ return new_Const(get_mode_one(mode));
+ }
+ }
+
+ if (is_constant_expression(expression->right)) {
+ long const valr = fold_constant(expression->left);
+ return valr != 0 ?
+ new_Const(get_mode_one(mode)) :
+ new_Const(get_mode_null(mode));