[llvm] [LAA,Loads] Use loop guards and max BTC if needed when checking deref. (PR #155672)

[via llvm-commits]

https://github.com/annamthomas commented:

Thanks for this! It handles more cases than what I had. 
Why the LoopGuards is a better option than the `isKnownPredicateAt`? One is compile-time, but looking at the SCEV code, both are really similar (handling assumes/guards and dominating conditions). 


https://github.com/llvm/llvm-project/pull/155672