[llvm] [InstCombine] Merge GEPs with the same index when the inner GEP has one use (PR #227960)

[Nikita Popov via llvm-commits]

nikic wrote:

There are some cases in llvm-opt-benchmark that time out, so probably you still get infinite loops. I guess it mostly happens to work out because the add will usually get visited and transformed first, but if you hit some rare worklist order, you will go into an infinite loop. I believe if you want to make this transform, you need to explicitly emit the multiply instead of an add.

https://github.com/llvm/llvm-project/pull/227960