[Sanddancer]

It's interesting, but a loop makes for smaller code, by a couple dozen bytes or so:

    int remaining = len % 4;

    if (remaining)
    {
        do
        {
            remaining--;
            h ^= (data[(length & ~3) + remaining] & 0xff) <<  (remaining * 8);
      } 
      while(remaining);

      h *= m;
    }

Fall-through's interesting, but at the same time, as architectures have changed, has become less useful. Self-modifying code at one time was near vital, but has fallen by the wayside, fall-through is doing much the same.