docs: public static int numberOfLeadingZerosSigned(long[] v) {
      for(int p = 0, ip = v.length - 1; p < v.length; p++, ip--) {
        if(v[ip] != 0) {
          return Long.numberOfLeadingZeros(v[ip]) + p * Long.SIZE;
        }
      }
      return -1;
    }