Re: Improve CRC32C performance on SSE4.2

Jesper Pedersen <jesperpedersen.db@gmail.com>

From: Jesper Pedersen <jesperpedersen.db@gmail.com>

To: Nathan Bossart <nathandbossart@gmail.com>

Cc: Andy Fan <zhihuifan1213@163.com>, John Naylor <johncnaylorls@gmail.com>, "Devulapalli, Raghuveer" <raghuveer.devulapalli@intel.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, "Shankaran, Akash" <akash.shankaran@intel.com>, Tomas Vondra <tomas@vondra.me>

Date: 2025-06-14T14:12:01Z

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 →

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

Hi Nathan,

On 6/14/25 9:56 AM, Nathan Bossart wrote:
> I'm also genuinely curious why folks are using -O0...
> 

Personally, I use

  -O0 -fno-omit-frame-pointer

for FlameGraph [1] investigations.

[1] https://github.com/brendangregg/FlameGraph

Best regards,
  Jesper