gcc/testsuite/gcc.dg/tree-ssa/pr34244.c

   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 }