static long intPairToLong(IntPair p) {
  ret p == null ? 0 : (((long) p.a) << 32) | (((long) p.b) & 0xFFFFFFFF);
}

static long intPairToLong(int a, int b) {
  ret (((long) a) << 32) | (((long) b) & 0xFFFFFFFF);
}