[PATCH] sched: Do not reorder RTX_FRAME_RELATED_P insns (PR78029)

Bernd Schmidt bschmidt@redhat.com
Wed Oct 26 12:30:00 GMT 2016


On 10/26/2016 01:19 PM, Segher Boessenkool wrote:
> Separate shrink-wrapping creates this not-all-that-smart code because
> the profile is quite messed up, and spread_components isn't super smart
> to begin with.  I'll have a patch for that soon, but even with it (and
> also without separate shrink-wrapping as far as I see) sched should not
> reorder insns that have CFI notes that conflict.

I think I agree with this as long as we really do prevent movement only 
if notes conflict. For example, I see no reason to forbid swapping 
normal register saves/restores, and doing so may well cost performance. 
So I think the patch needs to do better than just check RTX_FRAME_RELATED_P.


Bernd



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