[PATCH] D149783: [DAGCombiner] Add bswap(logic_op(bswap(x), y)) optimization

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:9987
+    // Need to ensure logic_op and bswap/bitreverse(x) doesn't have other uses
+    if (OldLHS.getOpcode() == Opcode && OldLHS.hasOneUse()) {
+      SDValue NewBitReorder = DAG.getNode(Opcode, DL, VT, OldRHS);
----------------
OldLHS might be from a node with multiple results - you need OldLHS->hasOneUse() (same for OldRHS below)


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D149783/new/

https://reviews.llvm.org/D149783