[PATCH] D37902: [CodeExtractor] Fix multiple bugs under certain shape of extracted region

[Jakub Kuderski via Phabricator via llvm-commits]

kuhar requested changes to this revision.
kuhar added a comment.
This revision now requires changes to proceed.

I have to agree with Danny, I'm not sure this version is correct. It should be fairly easy to use the batch updater here.
If we discover that doing incremental update makes the code too slow, that it's also great, as I still haven't come up a good benchmark to tell me what needs more optimization.



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Comment at: lib/Transforms/Utils/CodeExtractor.cpp:237
+    auto* OldPredNode = DT->getNode(OldPred);
+    const auto OrigChildren = OldPredNode->getChildren();
+    auto* NewBBNode = DT->addNewBlock(NewBB, OldPred);
----------------
Does this handle the self-loop case?


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Comment at: lib/Transforms/Utils/CodeExtractor.cpp:244
+    }
+    DT->updateDFSNumbers();
+  }
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In general, we prefer to update DFS numbers lazily and it's better to just invalidate them.


https://reviews.llvm.org/D37902