[PATCH] D148809: [DAG][AArch64] Limit preferIncOfAddToSubOfNot until after legalization if the node has wrap flags

[Dave Green via Phabricator via llvm-commits]

dmgreen created this revision.
dmgreen added reviewers: RKSimon, SjoerdMeijer, samtebbs, jaykang10.
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If the add node has wrap flags then they will be destroyed by converting to sub/not. The flags can be useful in converting to rhadd, for example, but that can happen late if the node types need to be legalized. This limits the preferIncOfAddToSubOfNot fold until after legalize DAG if the node have flags to allow more folding.


https://reviews.llvm.org/D148809

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/AArch64/arm64-vhadd.ll
  llvm/test/CodeGen/AArch64/sve-hadd.ll

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