Subject: Re: [PATCH 0/6] lib: rework bitreverse

From: Yury Norov <[email-masked]>
Date: Fri, 1 May 2026 21:40:00 -0400

On Thu, Apr 30, 2026 at 05:13:44PM -0400, Yury Norov wrote:
> This series is a resend for Jinjie Ruan's "arch/riscv: Add bitrev.h file
> to support rev8 and brev8" [1], my follow-up "lib: compile generic
> bitrev based on GENERIC_BITREVERSE" [2], and the fix for a build error
> reported by Nathan Chancellor [3].
> 
> No changes, except for combining pieces together and rebasing on top of
> the tree.
> 
> [1] https://lore.kernel.org/all/[email-masked]/
> [2] https://lore.kernel.org/all/[email-masked]/
> [3] https://lore.kernel.org/all/20260429202922.GA3575295@ax162/
> 
> Build-tested against x86 tinyconfig and defconfig, having disabled and
> enabiled CRC32 and BITREVERSE, correspondingly.

I've got a feedback from sashiko bot.

1. We need to do #if IS_DEFINED(CONFIG_CRC32) instead of #ifdef,
   because it may be a module.
2. Selecting GENERIC_BITREVERSE without BITREVERSE causes the unmet
   direct dependency warning:

   WARNING: unmet direct dependencies detected for GENERIC_BITREVERSE
  Depends on [n]: BITREVERSE [=n]
  Selected by [m]:
  - MYCONFIG [=m]

I'll send a v2 to fix it

Thanks,
Yury