gcc/testsuite/gcc.dg/tree-ssa/ssa-dce-3.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fdump-tree-cddce1" } */
   3
   4 int main(void)
   5 {
   6   unsigned i, j;
   7
   8   for (i = 1, j = 0; i != 0; i+=2)
   9     {
  10       j += 500;
  11       if (j % 7)
  12         {
  13           j++;
  14         }
  15       else
  16         {
  17           j--;
  18         }
  19     }
  20
  21   return 0;
  22 }
  23
  24 /* We now can prove the infiniteness of the loop during CCP and fail
  25    to eliminate the code inside the infinite loop because we start
  26    by marking the j % 7 condition as useful.  See PR45178.  */
  27
  28 /* We should eliminate the inner condition, but the loop must be preserved
  29    as it is infinite.  Therefore there should be just one phi node (for i):  */
  30 /* { dg-final { scan-tree-dump-times "PHI " 1 "cddce1" { xfail *-*-* } } } */
  31
  32 /* And one if (for the exit condition of the loop):  */
  33 /* { dg-final { scan-tree-dump-times "if " 1 "cddce1" } } */
  34
  35 /* { dg-final { cleanup-tree-dump "cddce1" } } */