private static int doCalculateNewFasterHashCode(
      int fastSignum, long fast0, long fast1, long fast2, int fastIntegerDigitCount, int fastScale) {

    long longHashCode;

    long key = fast0;

    // Hash code logic from original calculateLongHashCode

    key = (~key) + (key << 21); // key = (key << 21) - key - 1;
    key = key ^ (key >>> 24);
    key = (key + (key << 3)) + (key << 8); // key * 265
    key = key ^ (key >>> 14);
    key = (key + (key << 2)) + (key << 4); // key * 21
    key = key ^ (key >>> 28);
    key = key + (key << 31);

    longHashCode = key;

    key = fast1;

    key = (~key) + (key << 21); // key = (key << 21) - key - 1;
    key = key ^ (key >>> 24);
    key = (key + (key << 3)) + (key << 8); // key * 265
    key = key ^ (key >>> 14);
    key = (key + (key << 2)) + (key << 4); // key * 21
    key = key ^ (key >>> 28);
    key = key + (key << 31);

    longHashCode ^= key;

    key = fast2;

    key = (~key) + (key << 21); // key = (key << 21) - key - 1;
    key = key ^ (key >>> 24);
    key = (key + (key << 3)) + (key << 8); // key * 265
    key = key ^ (key >>> 14);
    key = (key + (key << 2)) + (key << 4); // key * 21
    key = key ^ (key >>> 28);
    key = key + (key << 31);

    longHashCode ^= key;

    key = fastSignum;

    key = (~key) + (key << 21); // key = (key << 21) - key - 1;
    key = key ^ (key >>> 24);
    key = (key + (key << 3)) + (key << 8); // key * 265
    key = key ^ (key >>> 14);
    key = (key + (key << 2)) + (key << 4); // key * 21
    key = key ^ (key >>> 28);
    key = key + (key << 31);

    longHashCode ^= key;

    key = fastIntegerDigitCount;

    key = (~key) + (key << 21); // key = (key << 21) - key - 1;
    key = key ^ (key >>> 24);
    key = (key + (key << 3)) + (key << 8); // key * 265
    key = key ^ (key >>> 14);
    key = (key + (key << 2)) + (key << 4); // key * 21
    key = key ^ (key >>> 28);
    key = key + (key << 31);

    longHashCode ^= key;

    key = fastScale;

    key = (~key) + (key << 21); // key = (key << 21) - key - 1;
    key = key ^ (key >>> 24);
    key = (key + (key << 3)) + (key << 8); // key * 265
    key = key ^ (key >>> 14);
    key = (key + (key << 2)) + (key << 4); // key * 21
    key = key ^ (key >>> 28);
    key = key + (key << 31);

    longHashCode ^= key;

    return (int) longHashCode;
  }
Return a BigDecimal representing the decimal.  The BigDecimal class is able to accurately
represent the decimal.

NOTE: We are not representing our decimal as BigDecimal now as OldHiveDecimal did, so this
is now slower.

@param fastSignum the sign (-1, 0, or +1)
@param fast0 word 0 of the internal representation
@param fast1 word 1
@param fast2 word 2
@param fastIntegerDigitCount the number of integer digits
@param fastScale the scale of the number
@return the BigDecimal equivalent
storage-api/src/java/org/apache/hadoop/hive/common/type/FastHiveDecimalImpl.java