[PATCH] D44199: [LoopRotate] Attempt to Rotate loops if it can lead to removing phi nodes.

[Dave Green via Phabricator via llvm-commits]

dmgreen added inline comments.


================
Comment at: lib/Transforms/Scalar/LoopRotation.cpp:190
+    if (!isa<PHINode>(Phi.getIncomingValueForBlock(Latch)))
+      continue;
+    return true;
----------------
efriedma wrote:
> Is the getIncomingValueForBlock() check necessary?  The previous any_of check should enough to ensure we're always eliminating a PHI node, I think?
> 
> If it is necessary, please add a testcase demonstrating why.
Nice. Like it. I was thinking this felt a bit too specific.

I've updated this and tried to come up with a sensible(ish) test.


https://reviews.llvm.org/D44199