From: | Nathan Bossart <nathandbossart(at)gmail(dot)com> |
---|---|
To: | David Rowley <dgrowleyml(at)gmail(dot)com> |
Cc: | "Amonson, Paul D" <paul(dot)d(dot)amonson(at)intel(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 21:08:10 |
Message-ID: | 20240318210810.GA582529@nathanxps13 |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Tue, Mar 19, 2024 at 10:02:18AM +1300, David Rowley wrote:
> I looked at your latest patch and tried out the performance on a Zen4
> running windows and a Zen2 running on Linux. As follows:
Thanks for taking a look.
> The only thing I'd question in the patch is in pg_popcount_fast(). It
> looks like you've opted to not do the 32-bit processing on 32-bit
> machines. I think that's likely still worth coding in a similar way to
> how pg_popcount_slow() works. i.e. use "#if SIZEOF_VOID_P >= 8".
> Probably one day we'll remove that code, but it seems strange to have
> pg_popcount_slow() do it and not pg_popcount_fast().
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.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2024-03-18 21:10:00 | Re: Improving EXPLAIN's display of SubPlan nodes |
Previous Message | David Rowley | 2024-03-18 21:02:18 | Re: Popcount optimization using AVX512 |