[llvm] [CycleInfo] Store blocks using Euler tour representation (PR #208614)

[Alexis Engelke via llvm-commits]

aengelke wrote:

> I will hold off on merging this until after branching is complete.

Should be the case now. :)

> Hopefully the experience we gained from CycleInfo (very cold) can be carried over to LoopInfo (hot path), unfortunately the API design in LoopInfo makes refactoring challenging.

Yeah. Porting users of LoopInfo to CycleInfo might be a more viable path to make LoopInfo less hot.



https://github.com/llvm/llvm-project/pull/208614