[llvm] VectorWiden pass to widen aleady vectorized instrctions (PR #67029)

[Nikita Popov via llvm-commits]

nikic wrote:

> > For the example in the description, isn't the issue that the SLP vectorizer doesn't support generating code for scalable vectors? Or has this recently been implemented?
> 
> SLP considers only scalars to vectorize, not already vectorized operations, nor scalable vectors.

Just to clarify, you are specifically interested in the case where the programmer has already written manually vectorized code, and you want to improve it further? So there are no scalar instructions at some earlier point in the pipeline?

https://github.com/llvm/llvm-project/pull/67029