Re: Speedup usages of pg_*toa() functions

>>>>> "David" == David Rowley <dgrowleyml@gmail.com> writes:

 David> This allows us to speed up a few cases. int2vectorout() should
 David> be faster and int8out() becomes a bit faster if we get rid of
 David> the strdup() call and replace it with a palloc()/memcpy() call.

What about removing the memcpy entirely? I don't think we save anything
much useful here by pallocing the exact length, rather than doing what
int4out does and palloc a fixed size and convert the int directly into
it.

i.e.

Datum
int8out(PG_FUNCTION_ARGS)
{
    int64       val = PG_GETARG_INT64(0);
    char       *result = palloc(MAXINT8LEN + 1);

    pg_lltoa(val, result);
    PG_RETURN_CSTRING(result);
}

For pg_ltoa, etc., I don't like adding the extra call to pg_ultoa_n - at
least on my clang, that results in two copies of pg_ultoa_n inlined.
How about doing it like,

int
pg_lltoa(int64 value, char *a)
{
    int         len = 0;
    uint64      uvalue = value;

    if (value < 0)
    {
        uvalue = (uint64) 0 - uvalue;
        a[len++] = '-';
    }
    len += pg_ulltoa_n(uvalue, a + len);
    a[len] = '\0';
    return len;
}

-- 
Andrew (irc:RhodiumToad)