[llvm] [SCEV] Cache recursive complexity comparisons (PR #223723)

[via llvm-commits]

ErikHogeman wrote:

> I think adding this cache back is fine if you're actually seeing IR in the wild that runs into this, but we should run this through llvm-compile-time-tracker

Thanks, to clarify a bit we saw this issue when running fuzzy testing on our LLVM based compiler, where some of the inputs would not finish compiling due to the exponential recursion here.

Happy to run the llvm-compile-time-tracker, do I email llvm at npopov.com to ask my fork to be added to this framework in that case?

https://github.com/llvm/llvm-project/pull/223723