code: private static boolean longLongCompareMagnitude(long hi0, long lo0, long hi1, long lo1) {
          if(hi0!=hi1) {
              return hi0<hi1;
          }
          return (lo0+Long.MIN_VALUE) <(lo1+Long.MIN_VALUE);
      }
docs: /*
  returns true if 128 bit number <hi0,lo0> is less then <hi1,lo1>
  hi0 & hi1 should be non-negative