https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119228
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), CALL_EXPR_FN (t), nargs, args); Which calls: return fold_builtin_n (loc, NULL_TREE, fndecl, argarray, n, false); so yes this is a dup, that is a null expr.