1  /* PR tree-optimization/34244  */
       2  /* { dg-do run } */
       3  /* { dg-options "-O2 " } */
       4  
       5  int __attribute__((noinline)) GetParent(void)
       6  {
       7    static int count = 0;
       8    count++;
       9    switch (count)
      10      {
      11      case 1:
      12      case 3:
      13      case 4:
      14          return 1;
      15      default:
      16          return 0;
      17      }
      18  }
      19  int __attribute__((noinline)) FindCommonAncestor(int aNode1, int aNode2)
      20  {
      21    if (aNode1 && aNode2) {
      22      int offset = 0;
      23      int anc1 = aNode1;
      24      for (;;) {
      25        ++offset;
      26        int  parent = GetParent();
      27        if (!parent)
      28          break;
      29        anc1 = parent;
      30      }
      31      int anc2 = aNode2;
      32      for (;;) {
      33        --offset;
      34        int  parent = GetParent();
      35        if (!parent)
      36          break;
      37        anc2 = parent;
      38      }
      39      if (anc1 == anc2) {
      40        anc1 = aNode1;
      41        anc2 = aNode2;
      42        while (offset > 0) {
      43          anc1 = GetParent();
      44          --offset;
      45        }
      46        while (offset < 0) {
      47          anc2 = GetParent();
      48          ++offset;
      49        }
      50        while (anc1 != anc2) {
      51          anc1 = GetParent();
      52          anc2 = GetParent();
      53        } 
      54        return anc1;
      55      }
      56    }
      57    return 0;
      58  }
      59  extern void abort (void);
      60  int main()
      61  {
      62    if (FindCommonAncestor (1, 1) != 0)
      63      abort ();
      64    return 0;
      65  }