[llvm] [RISCV] Handle zeroinitializer of vector tuple Type (PR #113995)

[Brandon Wu via llvm-commits]

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@@ -18008,6 +18008,22 @@ SDValue RISCVTargetLowering::PerformDAGCombine(SDNode *N,
     SDValue N0 = N->getOperand(0);
     EVT VT = N->getValueType(0);
     EVT SrcVT = N0.getValueType();
+    if (VT.isRISCVVectorTuple() && N0->getOpcode() == ISD::SPLAT_VECTOR) {
+      SDValue VL = DAG.getRegister(RISCV::X0, Subtarget.getXLenVT());
+      unsigned NF = VT.getRISCVVectorTupleNumFields();
+      unsigned NumScalElts = VT.getSizeInBits().getKnownMinValue() / (NF * 8);
+      SDValue EltVal = DAG.getConstant(0, DL, Subtarget.getXLenVT());
+      MVT ScalTy = MVT::getScalableVectorVT(MVT::getIntegerVT(8), NumScalElts);
+
+      SDValue Splat = DAG.getNode(RISCVISD::VMV_V_X_VL, DL, ScalTy,
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4vtomat wrote:

Yes!

https://github.com/llvm/llvm-project/pull/113995