On Tue, Aug 06, 2019 at 10:19:34AM +0800, Kewen.Lin wrote: > on 2019/8/6 上午5:21, Segher Boessenkool wrote: > > The other case is if not all shift counts are the same. I'm not sure > > we actually care much about this case :-) > > Got it, I think even for the "other" case, the neg operation without masking > is also safe since the hardware instructions do ignore the unrelated bits.
Oh it is perfectly safe. Only wondering how well we optimise this :-) Segher
