presto-spi/src/main/java/io/prestosql/spi/type/LongDecimalType.java/LongDecimalType/compareTo
class LongDecimalType:    @Override
    public int compareTo(Block leftBlock, int leftPosition, Block rightBlock, int rightPosition)
    {
        long leftLow = leftBlock.getLong(leftPosition, 0);
        long leftHigh = leftBlock.getLong(leftPosition, SIZE_OF_LONG);
        long rightLow = rightBlock.getLong(rightPosition, 0);
        long rightHigh = rightBlock.getLong(rightPosition, SIZE_OF_LONG);
        return compare(leftLow, leftHigh, rightLow, rightHigh);
    }