[llvm] [SCEV][LV] Invalidate LCSSA exit phis more thoroughly (PR #69909)

[Florian Hahn via llvm-commits]

fhahn wrote:

> I don't think constants or similar are relevant here, because the change of the phi node still has to preserve its value. If it previously evaluated to a constant, it has to evaluate to the same constant afterwards as well. The value doesn't change, but the old representation of the value may no longer be valid.

Yeah probably not necessary. Would still be good to handle AddRecs as well for completeness, even if they may already be invalidated.

https://github.com/llvm/llvm-project/pull/69909