On Wed, Feb 07, 2024 at 04:42:07PM -0800, Andres Freund wrote:
> On 2024-02-07 16:21:24 -0600, Nathan Bossart wrote:
>> The assembly for that looks encouraging, but I still need to actually test
>> it...
>
> Possible. For 16bit upcasting to 32bit is clearly the best way. For 32 bit
> that doesn't work, given the 32bit return, so we need something more.
For the same compASC() test, I see an ~8.4% improvement with your int64
code and a ~3.4% improvement with this:
int
compASC(const void *a, const void *b)
{
int result;
if (unlikely(pg_sub_s32_overflow(*(const int32 *) a,
*(const int32 *) b,
&result)))
{
if (*(const int32 *) a > *(const int32 *) b)
return 1;
if (*(const int32 *) a < *(const int32 *) b)
return -1;
return 0;
}
return result;
}
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
