1  /* PR optimization/10392
       2   * Reporter: marcus@mc.pp.se
       3   * Summary: [3.3/3.4 regression] [SH] optimizer generates faulty array indexing
       4   * Description:
       5   * The address calculation of an index operation on an array on the stack 
       6   * can _under some conditions_ get messed up completely
       7   *
       8   * Testcase tweaked by dank@kegel.com
       9   * Problem only happens with -O2 -m4, so it should only happen on sh4,
      10   * but what the heck, let's test other architectures, too.
      11   * Not marked as xfail since it's a regression.
      12  */
      13  /* { dg-do run } */
      14  /* { dg-options "-O2" } */
      15  /* { dg-options "-O2 -m4" { target sh4-*-* } } */
      16  extern void abort (void);
      17  const char *dont_optimize_function_away;
      18  
      19  const char *use(const char *str)
      20  {
      21  	dont_optimize_function_away = str;
      22  	if (str[0] != 'v')
      23  		abort();
      24  	if (str[1] < '1' || str[1] > '6')
      25  		abort();
      26  	if (str[2])
      27  		abort();
      28  	return str[2] ? "notused" : "v6";
      29  }
      30  
      31  const char *func(char *a, char *b)
      32  {
      33  	char buf[128];
      34  	unsigned char i;
      35  	const char *result;
      36  
      37  	char *item[] = {
      38  		"v1",
      39  		"v2",
      40  	};
      41  
      42  	buf[0] = 'v';
      43  	buf[1] = '3';
      44  	buf[2] = 0;
      45  
      46  	for (i = 0; i < 2; i++) {
      47  		/* bug is: following line passes wild pointer to use() on sh4 -O2 */
      48  		result = use(item[i]);
      49  
      50  		use(buf);
      51  		use(a);
      52  		use(b);
      53  		result = use(result);
      54  	}
      55  	return result;
      56  }
      57  
      58  int main()
      59  {
      60  	func("v4", "v5");
      61  	return 0;
      62  }
      63