[llvm] [LoopUnroll] Penalize interior control flow (PR #67137)

[Nikita Popov via llvm-commits]

nikic wrote:

I gave making full unroll cost modelling more precise a try, here's how it could look like: https://github.com/llvm/llvm-project/commit/26df05e27ce6c6742c6f523c926f4874ff5ca3ef But of course, that does result in non-trivial increases to text size: http://llvm-compile-time-tracker.com/compare.php?from=18be23f82a4c66ef6c838d3324979825acbcf49f&to=26df05e27ce6c6742c6f523c926f4874ff5ca3ef&stat=size-text I'm not entirely sure where to go from here -- making the cost modelling more precise clearly seems like a good idea, but that probably also needs a recalibration of unroll thresholds.

https://github.com/llvm/llvm-project/pull/67137