[PATCH] D57066: [TargetLowering] try harder to determine undef elements of vector binops

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: lib/CodeGen/SelectionDAG/TargetLowering.cpp:1472
+    if (C0 && C1 && C0.getValueType() == EltVT && C1.getValueType() == EltVT)
+      if (DAG.getNode(BO.getOpcode(), SDLoc(BO), EltVT, C0, C1).isUndef())
+        KnownUndef.setBit(i);
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What's the policy on creating nodes on the fly like this?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57066/new/

https://reviews.llvm.org/D57066