}
          // halfway between the representable values; do the half-whatever logic
          switch (mode) {
            case HALF_EVEN:
              return ((DoubleUtils.getSignificand(roundFloorAsDouble) & 1L) == 0)
                  ? roundFloorAsDouble
                  : roundCeilingAsDouble;
            case HALF_DOWN:
              return (x >= 0) ? roundFloorAsDouble : roundCeilingAsDouble;