#include <assert.h>
#include <stdio.h>

int main() {
  int i = 0xffff;

  asm("movl $23, %0"
      : "=r" (i) /* output */
      /* : no input */
      /* : no clobbered */
     );

  printf("i = %d\n", i);
  assert(i == 23);

  return 0;
}