[llvm] [LoopRotate] Rotate loop if this makes exit count computable (PR #162654)

[Florian Hahn via llvm-commits]

Marek =?utf-8?q?Sedláček?= <mr.mareksedlacek at gmail.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/162654 at github.com>


https://github.com/fhahn commented:

Looks like the impact is +0.11% for stage-O3, +0.17% stage1-ReleaseThinLTO. This still seems quite substantial. Do you have any data on the performance impact of the change? 

Do you have statistics on how many loops now additionally get runtime-unrolled/vectorized and how many extra rotations happen?

https://llvm-compile-time-tracker.com/compare.php?from=4f80c064eb2933c00c0ba9b7826aa3631cf3b5c2&to=09502c6f1d62526750ab4eee53d4c1271e9fbb69&stat=instructions%3Au

https://github.com/llvm/llvm-project/pull/162654