Re: [PATCH 00/17] Introduce and use generic parity32/64 helper

Jeremy Kerr
2025-02-24T07:59:12Z

Hi Kuan-Wei,

> Several parts of the kernel contain redundant implementations of parity
> calculations for 32-bit and 64-bit values. Introduces generic
> parity32() and parity64() helpers in bitops.h, providing a standardized
> and optimized implementation.

More so than __builtin_parity() ?

I'm all for reducing the duplication, but the compiler may well have a
better parity approach than the xor-folding implementation here. Looks
like we can get this to two instructions on powerpc64, for example.

Cheers,

Jeremy