[PATCH] D55274: [DagCombiner][X86] Simplify a ConcatVectors of a scalar_to_vector with undef.

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added a comment.

Maybe call the test file combine-concatvectors.ll ? That matches the other filenames we have.



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Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:16327
+        Op0.getOperand(0).hasOneUse() &&
+        Op0.getOperand(0).getOpcode() == ISD::SCALAR_TO_VECTOR) {
+      bool AllUndefs =
----------------
Use peekThroughOneUseBitcasts ?


================
Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:16342
+    }
+  }
+
----------------
This is all very similar to concat_vectors(scalar, undef) -> scalar_to_vector(sclr) at the beginning of visitCONCAT_VECTORS


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  https://reviews.llvm.org/D55274/new/

https://reviews.llvm.org/D55274