Re: [PATCH 17/39] clobber rbx in putuser_64.S

[Glauber Costa]

Andi Kleen wrote:
> Glauber Costa <gcosta@xxxxxxxxxx> writes:
>
> > Instead of clobbering r8, clobber rbx, which is the i386 way.
>
> Note rbx is callee saved on 64bit, so using that one means
> the surrounding function always has to save explicitely.
> Not the case with r8.
>
> There's a reason it is the way it is.
>
> -Andi
Right. Thanks for pointing this out.
However, r8 is not available for i386. We could use %ax, but it
holds part of the data for the call itself.

But for this case, I think we can come up with a macro that selects the 
appropriate register for each of them. Should be easy to do now that the 
code is merged.

Many thanks.
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