Re: add AVX2 support to simd.h

From: Nathan Bossart <nathandbossart(at)gmail(dot)com>
To: John Naylor <johncnaylorls(at)gmail(dot)com>
Cc: Ants Aasma <ants(at)cybertec(dot)at>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: add AVX2 support to simd.h
Date: 2024-03-21 18:38:23
Message-ID: 20240321183823.GA1800896@nathanxps13
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Thu, Mar 21, 2024 at 12:09:44PM -0500, Nathan Bossart wrote:
> On Thu, Mar 21, 2024 at 11:30:30AM +0700, John Naylor wrote:
>> Further, now that the algorithm is more SIMD-appropriate, I wonder
>> what doing 4 registers at a time is actually buying us for either SSE2
>> or AVX2. It might just be a matter of scale, but that would be good to
>> understand.
>
> I'll follow up with these numbers shortly.

It looks like the 4-register code still outperforms the 2-register code,
except for a handful of cases where there aren't many elements.

--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com

Attachment Content-Type Size
image/jpeg 30.0 KB
image/jpeg 23.8 KB

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Nathan Bossart 2024-03-21 18:39:37 Re: An improved README experience for PostgreSQL
Previous Message Robert Haas 2024-03-21 18:29:55 Re: documentation structure