[llvm] [VPlan] Add VPInstruction to unpack vector values to scalars. (PR #155670)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

I couldn't find any additional issues, but I'm afraid I'm missing context for VPlanUnroll: I've never played with the ScalableLast lane, so I'll leave this up to a more qualified review (@ayalz?). Thanks.

https://github.com/llvm/llvm-project/pull/155670