Re: add AVX2 support to simd.h

John Naylor <johncnaylorls@gmail.com>

From: John Naylor <johncnaylorls@gmail.com>

To: Nathan Bossart <nathandbossart@gmail.com>

Cc: Ants Aasma <ants@cybertec.at>, pgsql-hackers@postgresql.org

Date: 2024-01-03T14:13:52Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Improve style of pg_lfind32().
- 7188a7806d20 17.0 landed
Fix compiler warning for pg_lfind32().
- 1f42337be535 17.0 landed
Micro-optimize pg_lfind32().
- 7644a7340c8a 17.0 landed
Introduce helper SIMD functions for small byte arrays
- 9f225e992bed 17.0 cited
Optimize xid/subxid searches in XidInMVCCSnapshot().
- 37a6e5df3713 16.0 cited

On Tue, Jan 2, 2024 at 11:11 PM Nathan Bossart <nathandbossart@gmail.com> wrote:
>
> Perhaps I was too optimistic about adding support for newer instructions...
>
> I'm tempted to propose that we move forward with this patch as-is after
> adding a buildfarm machine that compiles with -mavx2 or -march=x86-64-v3.

That means that we would be on the hook to fix it if it breaks, even
though nothing uses it yet in a normal build. I have pending patches
that will break, or get broken by, this, so minus-many from me until
there is an availability story.