Re: [PATCH] SVE popcount support

Chiranmoy.Bhattacharya@fujitsu.com <chiranmoy.bhattacharya@fujitsu.com>

From: "Chiranmoy.Bhattacharya@fujitsu.com" <Chiranmoy.Bhattacharya@fujitsu.com>

To: Nathan Bossart <nathandbossart@gmail.com>

Cc: "Malladi, Rama" <ramamalladi@hotmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, "Ragesh.Hajela@fujitsu.com" <Ragesh.Hajela@fujitsu.com>, Salvatore Dipietro <dipiets@amazon.com>, "Devanga.Susmitha@fujitsu.com" <Devanga.Susmitha@fujitsu.com>

Date: 2025-03-23T17:11:07Z

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 →

Optimize popcount functions with ARM SVE intrinsics.
- 519338ace410 18.0 landed
Optimize popcount functions with ARM Neon intrinsics.
- 6be53c27673a 18.0 landed
Rename TRY_POPCNT_FAST to TRY_POPCNT_X86_64.
- 9ac6f7e7ceb6 18.0 landed

Looks good, the code is more readable now.

> For both Neon and SVE, I do see improvements with looping over 4
 > registers at a time, so IMHO it's worth doing so even if it performs the
 > same as 2-register blocks on some hardware.

There was no regression on Graviton 3 when using the 4-register version so can keep it.

-Chiranmoy