[PATCH] D118007: [SelectionDAG][RISCV] Teach getNode to fold bswap(bswap(x))->x.

[Craig Topper via Phabricator via llvm-commits]

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This can show up during when bitreverse is expanded to bswap and
swap of bits within a byte. If the input is already a bswap, we
should cancel them out before we further transform them in a way
that makes it harder to see the redundancy.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D118007

Files:
  llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  llvm/test/CodeGen/RISCV/bswap-bitreverse-ctlz-cttz-ctpop.ll

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