linux-kernel - Re: [PATCH v2] RAS/AMD/ATL: Remove bitwise_xor

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Message-ID: <aSRJdskInHGmbjIo@google.com>
Date: Mon, 24 Nov 2025 20:03:02 +0800
From: Kuan-Wei Chiu <visitorckw@...il.com>
To: Borislav Petkov <bp@...en8.de>
Cc: Nikolay Borisov <nik.borisov@...e.com>, linux-edac@...r.kernel.org,
	linux-kernel@...r.kernel.org, Yazen.Ghannam@....com
Subject: Re: [PATCH v2] RAS/AMD/ATL: Remove bitwise_xor_bits

Hi Borislav,

On Mon, Nov 24, 2025 at 12:05:26PM +0100, Borislav Petkov wrote:
> On Mon, Nov 24, 2025 at 04:57:51PM +0800, Kuan-Wei Chiu wrote:
> > > Both LLVM/GCC support a __builtin_parity function which is functionally
> > > equivalent to the custom bitwise_xor_bits() one. Let's simplify the code by
> > > relying on the built-in. No functional changes.
> > 
> > IIRC in some cases,
> 
> Which are those cases?
> 
> Do you have a trigger scenario?
> 
I did a quick search, and I believe it was this kernel test robot
report [1] that reminded me of this compiler behavior.

[1]: https://lore.kernel.org/oe-kbuild-all/202501312159.l6jNRaYy-lkp@intel.com/

Regards,
Kuan-Wei