presto-main/src/main/java/io/prestosql/type/DecimalOperators.java/XxHash64Operator/xxHash64
class XxHash64Operator:        @LiteralParameters({"p", "s"})
        @SqlType(StandardTypes.BIGINT)
        public static long xxHash64(@SqlType("decimal(p, s)") Slice value)
        {
            return XxHash64.hash(value);
        }