[PATCH] D146117: [RISCV]Optimize select_cc x, 0, ne, x, 1

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


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Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:10914
       }
+      // select_cc x, 0, ne, x, 1 -> seqz y, x + add x, x, y
+      if (isNullConstant(RHS) && isOneConstant(FalseV) && LHS == TrueV &&
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This comment mixes SelectionDAG names and instruction names. Can we use SelectionDAG throughout?


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Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:10918
+        SDValue SLTIU =
+            DAG.getSetCC(DL, VT, LHS, FalseV, ISD::CondCode::SETULT);
+        return DAG.getNode(ISD::ADD, DL, VT, LHS, SLTIU);
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Use seteq LHS, 0. That’s canonical.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D146117/new/

https://reviews.llvm.org/D146117