[llvm] [RISCV] Move vmv.v.v peephole from SelectionDAG to RISCVVectorPeephole (PR #100367)

[Pengcheng Wang via llvm-commits]

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@@ -65,6 +65,7 @@ class RISCVVectorPeephole : public MachineFunctionPass {
   bool convertToWholeRegister(MachineInstr &MI) const;
   bool convertToUnmasked(MachineInstr &MI) const;
   bool convertVMergeToVMv(MachineInstr &MI) const;
+  bool foldVMV_V_V(MachineInstr &MI);
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wangpc-pp wrote:

Hard to decide... I don't have a preference, maybe just keep it, we already have a lof of exceptions in RISCVISelLowering now.

https://github.com/llvm/llvm-project/pull/100367