Re: add AVX2 support to simd.h - Mailing list pgsql-hackers

From Nathan Bossart
Subject Re: add AVX2 support to simd.h
Date
Msg-id 20240321183823.GA1800896@nathanxps13
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In response to Re: add AVX2 support to simd.h  (Nathan Bossart <nathandbossart@gmail.com>)
Responses Re: add AVX2 support to simd.h
List 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

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