[PATCH] D102249: [LoopFlatten] Simplify loops so that the pass can operate on unsimplified loops.

[Dave Green via Phabricator via llvm-commits]

dmgreen added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/LoopFlatten.cpp:692
+    Changed |=
+        simplifyLoop(L, DT, LI, SE, AC, nullptr, false /* PreserveLCSSA */);
+    Changed |= formLCSSARecursively(*L, *DT, LI, SE);
----------------
stelios-arm wrote:
> fhahn wrote:
> > Would it not be more natural to do that directly in the main loop in `Flatten()` rather than duplicating the loop?
> Oh yes, I missed that. 
I'm not sure that's better. It would mean that the old pass manager duplicates the simplification/lcssa forming that it has already done through the pass dependencies. Put here it is only called once for the entire loop nest.


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https://reviews.llvm.org/D102249