As part of D84741, this adds a target hook for the preferPredicatedReductionSelect option and makes use of it under MVE, allowing us to tail predicate most reduction loops.
nit about the subject line:
[ARM][LV] Add a preferPredicatedReductionSelect target hook
[LV] - > [TTI]?
Not sure if this also needs to be split off from the TTI part, so that we have 3 parts: LV, TTI, and the ARM change. But I am fine with this, and will leave this up to you whatever you think is most convenient (you can also just commit the TTI part, then this change).
hey, that's new, I forgot but do we have a (negative) test for half types? :-)
I recently reorganised all the tail folding test (because it was getting a bit of a mess).