| From: | Nathan Bossart <nathandbossart(at)gmail(dot)com> |
|---|---|
| To: | "Amonson, Paul D" <paul(dot)d(dot)amonson(at)intel(dot)com> |
| Cc: | David Rowley <dgrowleyml(at)gmail(dot)com>, Andres Freund <andres(at)anarazel(dot)de>, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>, "Shankaran, Akash" <akash(dot)shankaran(at)intel(dot)com>, Noah Misch <noah(at)leadboat(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Matthias van de Meent <boekewurm+postgres(at)gmail(dot)com>, "pgsql-hackers(at)lists(dot)postgresql(dot)org" <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Popcount optimization using AVX512 |
| Date: | 2024-03-18 21:26:00 |
| Message-ID: | 20240318212600.GA655785@nathanxps13 |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Mon, Mar 18, 2024 at 09:22:43PM +0000, Amonson, Paul D wrote:
>> The only reason I left it out was because I couldn't convince myself that it
>> wasn't dead code, given we assume that popcntq is available in
>> pg_popcount64_fast() today. But I don't see any harm in adding that just in
>> case.
>
> I am not sure how to read this. Does this mean that for popcount32_fast
> and popcount64_fast I can assume that the x86(_64) instructions exists
> and stop doing the runtime checks for instruction availability?
I think my question boils down to "if pg_popcount_available() returns true,
can I safely assume I'm on a 64-bit machine?"
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | David Rowley | 2024-03-18 21:27:58 | Re: Popcount optimization using AVX512 |
| Previous Message | Amonson, Paul D | 2024-03-18 21:22:43 | RE: Popcount optimization using AVX512 |