Re: [PATCH v3 00/16] Introduce and use generic parity16/32/64 helper

Jeremy Kerr
2025-04-04T02:52:11Z

Hi Yuri & Kuan-Wei:

> Thank you for sharing your opinion on this fixed parity(). Your
> arguments may or may not be important, depending on what existing
> users actually need. Unfortunately, Kuan-Wei didn't collect
> performance numbers and opinions from those proposed users.

For the fsi-i2c side: this isn't a performance-critical path, and any
reasonable common approach would likely perform better that the current
per-bit implementation.

Our common targets for this driver would be arm and powerpc64le. In case
it's useful as a reference, using the kernel compilers I have to hand, a
__builtin_parity() is a library call on the former, and a two-instruction
sequence for the latter.

Cheers,

Jeremy