[PATCH] D65141: [DivergenceAnalysis] Add methods for querying divergence at use

[Nicolai Hähnle via Phabricator via llvm-commits]

nhaehnle added a comment.

Nice work! It's missing tests though -- I'm not sure if we want to print this additional information in the divergence printer, but definitely a test for the atomic optimizer pass is required.



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Comment at: llvm/lib/Analysis/LegacyDivergenceAnalysis.cpp:204-206
     for (auto &I : *InfluencedBB)
-      findUsersOutsideInfluenceRegion(I, InfluenceRegion);
+      if (!DV.count(&I))
+        findUsersOutsideInfluenceRegion(I, InfluenceRegion);
----------------
Please put braces around the `for` body (multi-line body).


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Comment at: llvm/lib/Analysis/LegacyDivergenceAnalysis.cpp:365
+  }
+  return DivergentValues.count(U->getUser()) || DivergentUses.count(U);
+}
----------------
What's the rationale for checking the user here as well?

For example, if the user is a binary operation that is divergent only because the **other** use is divergent, then I'd expect this function to return false...


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https://reviews.llvm.org/D65141