[PATCH] D103756: [DAG] Allow isNullOrNullSplat to see truncated zeroes

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added a comment.

> Whilst I'm here also add a call to peekThroughBitcasts as bitcast Zero is still Zero, and removed a related TODO comment from isOneOrOneSplat as the bitcast of 1 isn't always still 1.

Is this necessary for any of the test changes? I just wonder whether we should add this separately.



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Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:9605
+  N = peekThroughBitcasts(N);
+  ConstantSDNode *C = isConstOrConstSplat(N, AllowUndefs, true);
   return C && C->isNullValue();
----------------
/*AllowTruncation*/true ?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103756/new/

https://reviews.llvm.org/D103756