[llvm] [LoopVectorizer] Prune VFs based on plan register pressure (PR #132190)

[Sam Tebbs via llvm-commits]

SamTebbs33 wrote:

> I _think_ what's caused this is previously in LoopVectorizationCostModel::getMaximizedVFForTarget only VFs greater than MaxVectorElementCount could be discarded for excess register usage, but now any VF can be discarded.

Thanks for reporting that John. I'll investigate it.

https://github.com/llvm/llvm-project/pull/132190