#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;
  }