[PATCH] D140811: [DAGCombiner][X86] `visitVECTOR_SHUFFLE()`: splats with a single non-undef element are not splats

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added a comment.

Cheers - I'll review the x86 diffs and get back to you



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Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:23792
+    // might be free. But only if there are at least two non-undef indices.
+    if (OtherSVN->isSplat() &&
+        count(OtherSVN->getMask(), OtherSVN->getSplatIndex()) > 1)
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Instead of the count() - it might be worth adding a bool arg to isSplat()/isSplatMask() to only match splats with more than a single matching element?


Repository:
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  https://reviews.llvm.org/D140811/new/

https://reviews.llvm.org/D140811