[llvm] [VPlan] Add support for in-loop AnyOf reductions (PR #131830)

[Alexey Bataev via llvm-commits]

alexey-bataev wrote:

> > > > The in-loop reductions may be completely not profitable
> > > 
> > > 
> > > Yes, this is only profitable for EVL tail folding due to the vp.merge. The plan is to eventually use the TargetTransformInfo::preferInLoopReduction hook to only enable this for AnyOf reductions with EVL tail folding.
> > 
> > 
> > I mean, the in-loop reduction may be (significantly!!!)less profitable than vp.merge.
> 
> The in-loop reduction should be a single vcpop.m which I think should be cheap on most microarchitecture?

Nope, it is not

https://github.com/llvm/llvm-project/pull/131830