Re: Improve CRC32C performance on SSE4.2

John Naylor <johncnaylorls@gmail.com>

From: John Naylor <johncnaylorls@gmail.com>

To: Nathan Bossart <nathandbossart@gmail.com>

Cc: "Devulapalli, Raghuveer" <raghuveer.devulapalli@intel.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, "Shankaran, Akash" <akash.shankaran@intel.com>

Date: 2025-04-06T08:11:38Z

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 →

Include _mm512_zextsi128_si512() in AVX-512 configure probes.
- ccd5bc93fdfe 18.0 landed
Properly fix AVX-512 CRC calculation bug
- 43da394304fb 18.0 landed
Workaround code generation bug in clang
- f83f14881c7a 18.0 landed
Compute CRC32C using AVX-512 instructions where available
- 3c6e8c123896 18.0 landed
Inline CRC computation for small fixed-length input on x86
- e2809e3a1015 18.0 landed
Be more paranoid in configure's checks for CRC and POPCNT intrinsics.
- fdb5dd6331e3 18.0 cited

On Sat, Apr 5, 2025 at 5:15 AM Nathan Bossart <nathandbossart@gmail.com> wrote:
>
> I noticed that autoconf is defining USE_AVX512_CRC_WITH_RUNTIME_CHECK, but
> everywhere else expects USE_AVX512_CRC32C_WITH_RUNTIME_CHECK (with the
> "32C" included).  I tested the v16 patches (with the macro fixed and
> assertions enabled) on a machine with AVX-512 (verified with some extra
> debug logging), and everything passed.

Yikes, I even made a mental note to verify the relevant object file
still had the same contents as v14, and I clearly didn't do that on
the autoconf side. Thanks for running the smoke test! I fixed that,
made a couple more tiny comment changes and pushed.

--
John Naylor
Amazon Web Services