[llvm] [RISCV][CodeGen] Add initial vzip codegen support (PR #194548)

[Philip Reames via llvm-commits]

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@@ -5151,6 +5151,15 @@ static SDValue getSingleShuffleSrc(MVT VT, SDValue V1, SDValue V2) {
   return SDValue();
 }
 
+static bool isLegalVTForZvzip(MVT VT, const RISCVSubtarget &Subtarget,
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preames wrote:

Minor, but can you name this isLegalVTForZvzipOperand?  m8 is a legal _result_ type, just not a source _operand_ type.

https://github.com/llvm/llvm-project/pull/194548