1  /* { dg-do compile } */
       2  /* { dg-options "-O2 -fdump-tree-vrp1-alias -fdump-tree-vrp2-alias" } */
       3  
       4  void dead (unsigned n);
       5  void alive (unsigned n);
       6  
       7  void func (unsigned n, unsigned m)
       8  {
       9    if (n == 0)
      10      __builtin_unreachable();
      11    if (n == 1)
      12      __builtin_unreachable();
      13    if (n & 0x1)
      14      __builtin_unreachable();
      15    if (n == 2)
      16      __builtin_unreachable();
      17    if (n == 3)
      18      __builtin_unreachable();
      19    if (n & 0x2)
      20      __builtin_unreachable();
      21    if (n == 4)
      22      __builtin_unreachable();
      23    if (n == 5)
      24      __builtin_unreachable();
      25    if (n & 0x4)
      26      __builtin_unreachable();
      27    if (n == 6)
      28      __builtin_unreachable();
      29    if (n == 7)
      30      __builtin_unreachable();
      31   if (n <8)
      32     dead (n);
      33   if (n != m)
      34      __builtin_unreachable();
      35   alive (n);
      36   alive (m);
      37  }
      38  
      39  /* { dg-final { scan-tree-dump-not "dead" "vrp1" } } */
      40  /* { dg-final { scan-tree-dump-times "builtin_unreachable" 1 "vrp1" } } */
      41  /* { dg-final { scan-tree-dump-not "builtin_unreachable" "vrp2" } } */
      42  /* { dg-final { scan-tree-dump-times "fff8" 4 "vrp2" } } */