Unaligned memory access check

#include <stdio.h>

struct foo {
  unsigned char bar[8];
};

int main(int argc, char *argv[]) {
  struct foo x = {0, 1, 2, 3, 4, 5, 6, 7};
  unsigned int *p = (unsigned int *)(x.bar + 3);
  int i;

  if (argc > 1) {
#if defined(__GNUC__)
#if defined(__i386__)
    /* Enable Alignment Checking on x86 */
    __asm__ __volatile__("pushf\norl $0x40000,(%esp)\npopf");
#elif defined(__x86_64__)
    /* Enable Alignment Checking on x86_64 */
    __asm__ __volatile__("pushf\norl $0x40000,(%rsp)\npopf");
#elif defined(__mips64__)
    /* Enable Alignment Checking on mips64el */
#include <sys/sysmips.h>
    sysmips(MIPS_FIXADE, 0);
#endif
#endif
  }

  printf("*p = %08lx\n", *p);

  *p = 0xdeadface;

  for (i = 0; i <= 7; i++)
    printf("%02x ", x.bar[i]);
  printf("\n");
  return 0;
}