return sqrtFloor;
      case CEILING:
      case UP:
        int sqrtFloorInt = sqrtFloor.intValue();
        boolean sqrtFloorIsExact =
            (sqrtFloorInt * sqrtFloorInt == x.intValue()) // fast check mod 2^32
                && sqrtFloor.pow(2).equals(x); // slow exact check
        return sqrtFloorIsExact ? sqrtFloor : sqrtFloor.add(BigInteger.ONE);
      case HALF_DOWN:
      case HALF_UP:
      case HALF_EVEN: