[PATCH 12/18] arm64: fpsimd: Move fpsimd save/restore inline

[Mark Brown]

On Thu, May 28, 2026 at 05:15:14PM +0100, Mark Rutland wrote:

> Based on that discussion on the last patch, I've updated the commit
> message for this patch say:

>   I've used the SVE sequence for restoring FPCR, which uses an
>   unconditional write to FPCR, rather than the conditional write used by
>   the FPSIMD assembly sequence. I believe that in practice, this doesn't
>   matter to a real workload, and given it's possible for the
>   mis-predicted branch to cost more than the necessary
>   micro-architectural synchronization, I strongly suspect any
>   performance impact is within the noise. 

>   Looking at the history, the FPSIMD assembly sequence was changed to
>   use a conditional write to FPCR since 2014 in commit:

>     5959e25729a5 ("arm64: fpsimd: avoid restoring fpcr if the contents haven't change")

>   ... as described in the commit message, this was based on an
>   expectation of implementation style, and was not based on
>   benchmarking.

Thanks, that clarifies the issues and addresses all the concerns I had.
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