Re: [PATCH 4/5] xor/arm64: Use shared NEON intrinsics implementation from 32-bit ARM

"Ard Biesheuvel" <[email protected]> Fri, 27 Mar 2026 15:45:56 +0100

Newsgroups	gmane.linux.raid,gmane.linux.ports.arm.kernel,gmane.linux.kernel.cryptoapi
Message-ID	<[email protected]>

On Fri, 27 Mar 2026, at 14:50, Christoph Hellwig wrote:
> On Fri, Mar 27, 2026 at 12:30:52PM +0100, Ard Biesheuvel wrote:
>> From: Ard Biesheuvel <[email protected]>
>> 
>> Tweak the arm64 code so that the pure NEON intrinsics implementation of
>> XOR is shared between arm64 and ARM.
>
> Instead of hiding the implementation in a header, just split xor-neon.c
> into two .c files, one of which could be built by arm32 as well.

That is what patch 3/5 does. This patch wires up that version into arm64, and drops the copy that has become redundant as a result.

> probably
> in the arm/ instead of the arm64/ subdirectory, but we can also add a
> new arm-common one if that's what the arm maintainers prefer.

Having the shared pure NEON version in arm/ is perfectly fine.

Building it as a separate compilation unit for arm64 should also be straight-forward, the only issue is that the 2-way NEON version needs to be shared with the EOR3 compilation unit.