[llvm] [RFC] Memory Model Relaxation Annotations (PR #78569)

[Pierre van Houtryve via llvm-commits]

Pierre-vh wrote:

> ere is an opposite "safe by default" choice, which is to say that we will teach every conceivable transform to back off when MMRAs are present, and then re-enable each of them by teaching them how to deal with MMRAs. That sounds like overkill. The first choice is

Looking back, I also think that in some cases, dropping MMRAs may be acceptable if it means removing an entire branch/load/store/etc, so it was indeed premature of me to prevent things like CSE in the presence of MMRAs.

https://github.com/llvm/llvm-project/pull/78569