gcc/testsuite/gcc.dg/pr10392-1.c

   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 const char *dont_optimize_function_away;
  17
  18 const char *use(const char *str)
  19 {
  20         dont_optimize_function_away = str;
  21         if (str[0] != 'v')
  22                 abort();
  23         if (str[1] < '1' || str[1] > '6')
  24                 abort();
  25         if (str[2])
  26                 abort();
  27         return str[2] ? "notused" : "v6";
  28 }
  29
  30 const char *func(char *a, char *b)
  31 {
  32         char buf[128];
  33         unsigned char i;
  34         const char *result;
  35
  36         char *item[] = {
  37                 "v1",
  38                 "v2",
  39         };
  40
  41         buf[0] = 'v';
  42         buf[1] = '3';
  43         buf[2] = 0;
  44
  45         for (i = 0; i < 2; i++) {
  46                 /* bug is: following line passes wild pointer to use() on sh4 -O2 */
  47                 result = use(item[i]);
  48
  49                 use(buf);
  50                 use(a);
  51                 use(b);
  52                 result = use(result);
  53         }
  54         return result;
  55 }
  56
  57 int main()
  58 {
  59         func("v4", "v5");
  60         return 0;
  61 }
  62