presto-main/src/main/java/io/prestosql/type/SmallintOperators.java/SmallintOperators/hashCode
class SmallintOperators:    @ScalarOperator(HASH_CODE)
    @SqlType(StandardTypes.BIGINT)
    public static long hashCode(@SqlType(StandardTypes.SMALLINT) long value)
    {
        return SmallintType.hash((short) value);
    }