[llvm] [RISCV] Add codegen support for ri.vinsert.v.x and ri.vextract.x.v (PR #136708)

[Philip Reames via llvm-commits]

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@@ -9686,6 +9693,26 @@ SDValue RISCVTargetLowering::lowerINSERT_VECTOR_ELT(SDValue Op,
         return Vec;
       return convertFromScalableVector(VecVT, Vec, DAG, Subtarget);
     }
+
+    // Use ri.vinsert.v.x if available.
+    if (Subtarget.hasVendorXRivosVisni() && VecVT.isInteger() &&
+        isValidInsertExtractIndex(Idx)) {
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preames wrote:

This is a good question, one I hadn't considered.  The current scheme is what we've been using downstream and seems to generate decent code, but I'll watch for the vtype issue and may readjust this in a future patch.  

https://github.com/llvm/llvm-project/pull/136708