[PATCH] D152366: [LoopVectorize] Allow inner loop runtime checks to be hoisted above an outer loop

[David Sherwood via Phabricator via llvm-commits]

david-arm added a comment.

Hi @fhahn, when vectorising as part of the normal pipeline we always run LICM after the vectoriser which ensures the runtime checks are hoisted out. This is why we see the improvement for x264. However, if we vectorise a loop during the LTO pipeline then you're right that LICM is not currently one. This will probably change with D143631 <https://reviews.llvm.org/D143631> though, since there are other problems with not running LICM after InstCombine in the LTO pipeline.

I've tried cleaning up the tests, and added a new one too. I'll continue working separately on adding a specific test to the llvm test suite, although obviously the test suite won't be run with this new flag enabled.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D152366/new/

https://reviews.llvm.org/D152366