probe process.function("foo").return {
    printf("x3 = %#x\n", register("x3"));
    printf("u x3 = %#x\n\n", u_register("x3"));

    printf("w3 = %#x\n", register("w3"));
    printf("u w3 = %#x\n", u_register("w3"));
    exit()
}
