[PATCH] D110234: [LoopFlatten] Updating Phi nodes after IV widening

[Sjoerd Meijer via Phabricator via llvm-commits]

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In rG6a076fa9539e <https://reviews.llvm.org/rG6a076fa9539ee6eea078368bc5298e381c1c059e>, a problem with updating the old/narrow phi nodes after IV widening was introduced. If after widening of the IV the transformation is *not* applied, the narrow phi node was incorrectly modified, which should only happen if flattening happens. This can be seen in the added test `widen-iv2.ll`, which incorrectly had 1 incoming value, but should have its original 2 incoming values, which is now restored.


https://reviews.llvm.org/D110234

Files:
  llvm/lib/Transforms/Scalar/LoopFlatten.cpp
  llvm/test/Transforms/LoopFlatten/widen-iv2.ll

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