1  /* { dg-do compile } */
       2  /* { dg-options "-O2 -ftree-tail-merge -fdump-tree-pre" } */
       3  
       4  int z;
       5  int x;
       6  
       7  void
       8  f (int c, int d)
       9  {
      10    if (c)
      11      z = 5;
      12    else
      13      {
      14        if (d)
      15  	x = 4;
      16        z = 5;
      17      }
      18  }
      19  
      20  /* { dg-final { scan-tree-dump-times "duplicate of" 1 "pre"} } */
      21  /* { dg-final { scan-tree-dump-times "z = 5" 1 "pre"} } */