int logFloor = log10Floor(x);
    long floorPow = powersOf10[logFloor];
    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(x == floorPow);
      // fall through
      case FLOOR:
      case DOWN:
        return logFloor;
      case CEILING:
      case UP:
        return logFloor + lessThanBranchFree(floorPow, x);
      case HALF_DOWN:
      case HALF_UP:

      }
    }

    int floorLog = approxLog10;
    BigInteger floorPow = approxPow;
    int floorCmp = approxCmp;

    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(floorCmp == 0);
      // fall through
      case FLOOR:
      case DOWN:
        return floorLog;

      case CEILING:
      case UP:
        return floorPow.equals(x) ? floorLog : floorLog + 1;

    *   Added 16-bit int type support for built-in op `less`, `greater_than`, `equal`
    *   Added 8-bit and 16-bit support for `floor_div` and `floor_mod`.
    *   Added 16-bit and 32-bit int support for the built-in op `bitcast`.
    *   Added 8-bit/16-bit/32-bit int/uint support for the built-in op `bitwise_xor`