20020118-1.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

/* This tests an insn length of sign extention on h8300 port.  */

extern void exit (int);

volatile signed char *q;
volatile signed int n;

void
foo (void)
{
  signed char *p;

  for (;;)
    {
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
      p = (signed char *) q; n = p[2];
    }
}

int
main ()
{
  exit (0);
}