[PATCH] D86133: [LoopNest] False negative of `arePerfectlyNested` with LCSSA loops

[Ta-Wei Tu via Phabricator via llvm-commits]

TaWeiTu marked 4 inline comments as done.
TaWeiTu added inline comments.


================
Comment at: llvm/lib/Analysis/LoopNestAnalysis.cpp:239
+      auto *PN = dyn_cast<PHINode>(&I);
+      return PN && PN->getName().endswith(".lcssa");
+    });
----------------
Whitney wrote:
> Don't think checking name is ideal, because it can be changed in between passes. 
> How about PHINodes that have single incoming entry?
The LCSSA PHINodes may have two incoming entries, one from the exit block of the inner loop and the other from the header of the outer loop.
I'm not entirely sure about whether the condition is correct and sufficient, though.


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  https://reviews.llvm.org/D86133/new/

https://reviews.llvm.org/D86133