[PATCH] D41953: [LoopUnroll] Unroll and Jam

Dave Green via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Apr 3 12:35:08 PDT 2018


dmgreen added a comment.

Sorry Sam, I missed your comment somehow in a number of other emails. Sorry about that.

By a bit awkward - I wasn't referring to unroll and jam doing the inner unroll. That sounds like a fine idea, like we have here it just tries to call tryToUnrollLoop again.

I just meant that two passes in the same LoopPassManager will process inner loops first for all passes, then move on to the outer loops. So we would either need get the inner loop unroll to not unroll (preventing the outer unroll and jam) or we'd need to ensure the lpm is split in two (which may be fine, and may help with the other issues around analysis dependencies and not needing the explicit inner unroll). Providing this wont change the pass ordering for other code, which I don't think it will if I'm reading this pass pipeline correctly, this sounds like the best way to go to me.

I'll give it a try like that and see how it looks.


Repository:
  rL LLVM

https://reviews.llvm.org/D41953





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