[llvm] [RISCV][CodeGen] Add CodeGen support of Zvzip extension (PR #189801)

[Pengcheng Wang via llvm-commits]

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@@ -29,3 +29,121 @@ let Predicates = [HasStdExtZvzip], Constraints = "@earlyclobber $vd" in {
     def VPAIRO_VV : VALUVV<0b001111, OPMVV, "vpairo.vv">;
   }
 } // Predicates = [HasStdExtZvzip]
+
+// Returns a vector. Operand 0 and 1 are vectors, operand 2 is a passthru,
+// operand 3 is a mask, operand 4 is VL.
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wangpc-pp wrote:

It can be simplified to `(vd (op vs2, vs1, passthru, mask, vl)`.

https://github.com/llvm/llvm-project/pull/189801