Hi! On Fri, May 29, 2020 at 09:32:49AM +0100, Richard Sandiford wrote: > There's nothing to stop us using masks and lengths in the same loop > in future if we need to. It would “just” be a case of setting up both > the masks and the lengths in vect_set_loop_condition. But the point is > that doing that would be extra code, and there's no point writing that > extra code until it's needed.
You won't ever get it right even, because you do not know exactly what will be needed :-) > If some future arch does support both mask-based and length-based > approaches, I think that's even less reason to make a binary choice > between them. How we prioritise the length and mask approaches when > both are available is something that we'll have to decide at the time. > > If your concern is that the arch might support masked operations > without wanting them to be used for loop control, we could test for > that case by checking whether while_ult_optab is implemented. Heh, sneaky. But at least for now it will work fine, and it is local, and not hard to change later. Segher
