z = (struct rtavl_node *) &tree->rtavl_root;
y = tree->rtavl_root;
if (tree->rtavl_root != NULL)
  for (q = z, p = y; ; q = p, p = p->rtavl_link[dir])
    {
      int cmp = tree->rtavl_compare (item, p->rtavl_data, tree->rtavl_param);
      if (cmp == 0)
        return &p->rtavl_data;

      if (p->rtavl_balance != 0)
        z = q, y = p, k = 0;
      da[k++] = dir = cmp > 0;

      if (dir == 0)
        {
          if (p->rtavl_link[0] == NULL)
            break;
        }
      else /* |dir == 1| */
        {
          if (p->rtavl_rtag == RTAVL_THREAD)
            break;
        }
    }
else
  {
    p = (struct rtavl_node *) &tree->rtavl_root;
    dir = 0;
  }