Re: [PATCH 1/2] ARM: copypage-fa: add kto and kfrom to input operands list

[Nicolas Pitre]

On Tue, 6 Nov 2018, Robin Murphy wrote:

> On 06/11/2018 04:49, Nicolas Pitre wrote:
> [...]
> >> r3 and r5 are not used above, so no need to have them in the clobber
> >> list.
> > 
> > They are used. ldrd and strd instructions always use a pair of
> > consecutive registers. So "ldrd r2, ..." loads into r2-r3 and "ldrd r4, ..."
> > loads into r4-r5.
> 
> FWIW, since we should now be enabling unified syntax everywhere, I guess we
> could probably rewrite all those ldrd/strd to the UAL 3-operand form - i.e.
> "ldrd r2, r3, [...]" - if we really cared for the extra clarity.

Good idea. Worthy of a separate patch though.


Nicolas