[llvm] [LAA] Hoist setting condition for RT-checks (PR #128045)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

> > I added one case where this changes behavior in [8bdcd0a](https://github.com/llvm/llvm-project/commit/8bdcd0a96e65557c8c3bf506d186c49002db6463)
> 
> Interesting, I seem to have misunderstood something.

Okay, it doesn't look like I misunderstood anything, and this is an edge-case I didn't account for: it returns unknown straight away for two access-pairs, not hitting any code changed by the patch, and returns a valid DependenceDistanceStrideAndSize (later determined as NoDep) for the third access-pair while setting the condition for RT-checks. While I think the logic is far from precise, I think the patch and the test change are correct, within the limitations of the existing code.

https://github.com/llvm/llvm-project/pull/128045