[PATCH] D80236: [VectorCombine] position pass after SLP in the optimization pipeline rather than before

[Bjorn Pettersson via Phabricator via llvm-commits]

bjope added a comment.

In D80236#2091847 <https://reviews.llvm.org/D80236#2091847>, @spatel wrote:

> In D80236#2091336 <https://reviews.llvm.org/D80236#2091336>, @nikic wrote:
>
> > @bjope Tracing back the changes here, what happened is that originally there was an EarlyCSE run in ExtraVectorizerPasses, then it got moved into the main pipeline as part of the VectorCombine introduction, then it got moved after SLP in this patch and then it got dropped entirely afterwards. So the EarlyCSE run that was present in ExtraVectorizerPasses is now gone as a side-effect of this shuffling around. So I'd say, feel free to just add it back (it was the first pass in the https://github.com/llvm/llvm-project/blob/2dc664d578f0e9c8ea5975eed745e322fa77bffe/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp#L734 block) and restore the status quo of LLVM 10.
>
>
> Thanks for tracking that down! Hopefully back to LLVM10 state with:
>  rG098e48a6a15 <https://reviews.llvm.org/rG098e48a6a1555549eed38b9dd1bb5aa0355560ae>


Thanks! Both for the detective work and the patch.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D80236/new/

https://reviews.llvm.org/D80236