[llvm] [RFC][LV] VPlan-based cost model (PR #67647)

[Florian Hahn via llvm-commits]

fhahn wrote:

> Do you want to get your PR reviewed and merged first?

I think it would be good to make sure we get the right foundation in first. I created a separate PR for the type analysis only to start with: #69013

> About computing cost in the recipe itself, I see your point.
> In addition to compute the throughput cost, we might consider other costs like register spills and loop exit overhead, so I prefer a separate class for these cost computation to avoid the need to increase the number of the VPRecipeBase interfaces and treat it as a kind of IR.

I think it makes sense to consider those additional cases once we get to it.

https://github.com/llvm/llvm-project/pull/67647