[llvm] [RISCV][P-ext] Fold packed insert-into-zero to zero-extend (PR #208006)

[Sam Elliott via llvm-commits]

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@@ -709,6 +712,9 @@ RISCVTargetLowering::RISCVTargetLowering(const TargetMachine &TM,
           {ISD::SETGE, ISD::SETUGT, ISD::SETUGE, ISD::SETULE, ISD::SETLE},
           P64VecVTs, Expand);
       setCondCodeAction({ISD::SETNE, ISD::SETGT}, P64VecVTs, Custom);
+      // Operation legalization queries the action using the result type.
+      setOperationAction(ISD::INSERT_SUBVECTOR, {MVT::v4i16, MVT::v8i8},
+                         Custom);
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lenary wrote:

Are we missing `v2i32` here? Or is that not `insert_subvector`?

https://github.com/llvm/llvm-project/pull/208006