[llvm] [LV] Use shl for (VFxUF * vscale) when creating minimum iter check. (PR #153495)

[Florian Hahn via llvm-commits]

fhahn wrote:

Yep, InstSimplifyFolder can only fold to an existing instruction, so it cannot create a new SHL instruction

https://github.com/llvm/llvm-project/pull/153495