[PATCH] D151029: [DAG] Combine insert(shuffle(load), load, 0) into a single load

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:20927
+  if (!Shuffle || !all_of(enumerate(Shuffle->getMask()), [&](auto P) {
+        return InsIndex == P.index() ||
+               (InsIndex == 0 && P.value() == (int)P.index() - 1) ||
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I think we could allow undef mask elements as well, but we'd have to ensure that we could still deference the entire vector width?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D151029/new/

https://reviews.llvm.org/D151029