[PATCH] D42691: [SimplifyCFG] Relax restriction for folding unconditional branches

Eli Friedman via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Mon Feb 5 12:11:17 PST 2018


efriedma added inline comments.


================
Comment at: test/Transforms/SimplifyCFG/UncondBranchToHeader.ll:16
+  br label %header
+exit:
+  ret i32 %i
----------------
skatkov wrote:
> skatkov wrote:
> > efriedma wrote:
> > > Do we really need SimplifyCFG to rotate loops?  We have a dedicated LoopRotate pass for this sort of transform.
> > > 
> > > But I guess it's okay.
> > Hi Eli, I did not follow what you mean here as rotate loop?
> > 
> > Header will be the same. In this particular case the loop will just consists from one basic block header after transformation...
> Or you mean that before it was not bottom formed loop and now it is?
I don't think I've ever seen the term "bottom formed loop", but yes, that's what I meant.


Repository:
  rL LLVM

https://reviews.llvm.org/D42691





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