>> > I propose the following, yet SLP have to use a NULL as a loop info
>> > which looks somewhat hacky.
>>
>> I think this is overengineering. -fvect-cost-model will do as
>> workaround. And -fsimd-vect-cost-model has what I consider
>> duplicate - "simd" and "vect".
>
> I think it is a good idea, though I agree about s/simd-vect/simd/ and
> I'd use VECT_COST_MODEL_DEFAULT as the default, which would mean
> just use -fvect-cost-model.
that's ok, since we'd have a way to force those 'simd' loops.
>
>> > @@ -2929,6 +2929,11 @@ vect_estimate_min_profitable_iters
>> > (loop_vec_info loop_vinfo,
>> > /* vector version will never be profitable. */
>> > else
>> > {
>> > + if (LOOP_VINFO_LOOP (loop_vinfo)->force_vect)
>> > + {
>> > + pedwarn (vect_location, 0, "Vectorization did not happen
>> > for the loop");
>> > + }
>
> pedwarn isn't really desirable for this, you want just warning,
> but some warning you can actually also turn off.
> -Wopenmp-simd (and we'd use it also when we ignore #pragma omp declare simd
> because it wasn't useful/desirable).
consider a user is interested in enabling warning-as-error for this case?
can we disable the pedwarn the same way?
Sergos
>
> Jakub
