[llvm] [LoongArch] lower SCALAR_TO_VECTOR to INSERT_VECTOR_ELT (PR #122863)

[via llvm-commits]

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@@ -446,10 +448,26 @@ SDValue LoongArchTargetLowering::LowerOperation(SDValue Op,
     return lowerVECTOR_SHUFFLE(Op, DAG);
   case ISD::BITREVERSE:
     return lowerBITREVERSE(Op, DAG);
+  case ISD::SCALAR_TO_VECTOR:
+    return lowerSCALAR_TO_VECTOR(Op, DAG);
   }
   return SDValue();
 }
 
+SDValue
+LoongArchTargetLowering::lowerSCALAR_TO_VECTOR(SDValue Op,
+                                               SelectionDAG &DAG) const {
+  SDLoc DL(Op);
+  MVT OpVT = Op.getSimpleValueType();
+
+  SDValue Vector = DAG.getUNDEF(OpVT);
+  SDValue Val = Op.getOperand(0);
+  SDValue Idx = DAG.getConstant(0, DL, Subtarget.getGRLenVT());
+
+  Vector = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, OpVT, Vector, Val, Idx);
+  return Vector;
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zhaoqi5 wrote:

`return DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, OpVT, Vector, Val, Idx);`

https://github.com/llvm/llvm-project/pull/122863