[llvm] [LV] Align legacy cost model to vplan-based model for gather/scatter w/ uniform addr. (PR #155739)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

Does this need to go together with the changes to VPMemoryRecipe::computeCost?

https://github.com/llvm/llvm-project/pull/155739