// SPDX-License-Identifier: GPL-2.0 #include <stdint.h> volatile uint64_t x; int main(int argc, char *argv[]) { uint64_t old, new = argc; argv = argv; do { old = __sync_val_compare_and_swap(&x, 0, 0); } while (!__sync_bool_compare_and_swap(&x, old, new)); return old == new; }