public static boolean fastAdd(
      FastHiveDecimal fastLeft,
      FastHiveDecimal fastRight,
      FastHiveDecimal fastResult) {
    return fastAdd(
        fastLeft.fastSignum, fastLeft.fast0, fastLeft.fast1, fastLeft.fast2,
        fastLeft.fastIntegerDigitCount, fastLeft.fastScale,
        fastRight.fastSignum, fastRight.fast0, fastRight.fast1, fastRight.fast2,
        fastRight.fastIntegerDigitCount, fastRight.fastScale,
        fastResult);
  }
Handle decimal addition when the values have different scales.
storage-api/src/java/org/apache/hadoop/hive/common/type/FastHiveDecimalImpl.java