[llvm] [IVDescriptors] Check for null SE before dereference in getMinMaxRecurrence. (PR #195798)

[Craig Topper via llvm-commits]

topperc wrote:

> > Some callers don't pass SCEV.
> 
> Are there in-tree callers that don't pass it? If so, could you add an end-to-end test?

There's one in LoopInterchange. I'll see if I can write a test.

https://github.com/llvm/llvm-project/pull/195798