[llvm] [LoopVectorize][AArch64][SVE] Generate wide active lane masks (PR #81140)

[Momchil Velikov via llvm-commits]

momchil-velikov wrote:


> > > Perhaps we'll need to add wrap flag support to get.active.mask to make that job easier but this should not be all that different to what LoopVectorize would have to do anyway.
> > 
> > What would be the advantage compared to the current approach?
> 
> It would remove the need for yet another TTI function and hence divergence within LoopVectorize. So perhaps not great reasons but what's the advantage of the current approach if neither hamper code generation?

The advantage it does not require updating other backends to handle a different `get_active_lane_mask` and does not require a  change to the LLVM IR spec.



https://github.com/llvm/llvm-project/pull/81140