RE: Popcount optimization using AVX512

Amonson, Paul D <paul.d.amonson@intel.com>

From: "Amonson, Paul D" <paul.d.amonson@intel.com>

To: Nathan Bossart <nathandbossart@gmail.com>, David Rowley <dgrowleyml@gmail.com>

Cc: Andres Freund <andres@anarazel.de>, Alvaro Herrera <alvherre@alvh.no-ip.org>, "Shankaran, Akash" <akash.shankaran@intel.com>, Noah Misch <noah@leadboat.com>, Tom Lane <tgl@sss.pgh.pa.us>, "Matthias van de Meent" <boekewurm+postgres@gmail.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>

Date: 2024-03-19T22:56:01Z

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 →

Fix __attribute__((target(...))) usage.
- 41b98ddb77bf 18.0 landed
Use __attribute__((target(...))) for AVX-512 support.
- f78667bd910e 18.0 landed
Fix code for probing availability of AVX-512.
- 598e0114a3b1 17.0 landed
Optimize visibilitymap_count() with AVX-512 instructions.
- 41c51f0c68b2 17.0 landed
Optimize pg_popcount() with AVX-512 instructions.
- 792752af4eb5 17.0 landed
Inline pg_popcount() for small buffers.
- deb1486c7d36 17.0 landed
Avoid function call overhead of pg_popcount() in syslogger.c.
- 4133c1f45c54 17.0 landed
Refactor code for setting pg_popcount* function pointers.
- 6687430c98f3 17.0 landed
Inline pg_popcount{32,64} into pg_popcount().
- cc4826dd5e52 17.0 landed
Remove MSVC scripts
- 1301c80b2167 17.0 cited
Use ARMv8 CRC instructions where available.
- f044d71e331d 11.0 cited
Use Intel SSE 4.2 CRC instructions where available.
- 3dc2d62d0486 9.5.0 cited

Attachments

v10-0001-Refactor-inlining-and-direct-calls-for-_slow-functio.patch (application/octet-stream) patch v10-0001
v10-0002-Refactor-Seperated-slow-fast-and-choose-functionalit.patch (application/octet-stream) patch v10-0002
v10-0003-Feature-Add-POPCNT512-accelerated-functionality-for-.patch (application/octet-stream) patch v10-0003

> -----Original Message-----
> From: Nathan Bossart <nathandbossart@gmail.com>
>
> Committed.  Thanks for the suggestion and for reviewing!
> 
> Paul, I suspect your patches will need to be rebased after commit cc4826d.
> Would you mind doing so?

Changed in this patch set.

* Rebased.
* Direct *slow* calls via macros as shown in example patch.
* Changed the choose filename to be platform specific as suggested.
* Falls back to intermediate "Fast" methods if AVX512 is not available at runtime.
* inline used where is makes sense, remember using "extern" negates "inline".
* Fixed comment issues pointed out in review.

I tested building with and without TRY_POPCOUNT_FAST, for both configure and meson build systems, and ran in CI.

Thanks,
Paul