[llvm] [RISCV] Initial codegen support for zvqdotq extension (PR #137039)

[Sergei Barannikov via llvm-commits]

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@@ -18101,6 +18101,118 @@ static SDValue performBUILD_VECTORCombine(SDNode *N, SelectionDAG &DAG,
                      DAG.getBuildVector(VT, DL, RHSOps));
 }
 
+static SDValue lowerVQDOT(unsigned Opc, SDValue Op0, SDValue Op1,
+                          const SDLoc &DL, SelectionDAG &DAG,
+                          const RISCVSubtarget &Subtarget) {
+  assert(RISCVISD::VQDOT_VL == Opc || RISCVISD::VQDOTU_VL == Opc ||
+         RISCVISD::VQDOTSU_VL == Opc);
+  MVT VT = Op0.getSimpleValueType();
+  assert(VT == Op1.getSimpleValueType() &&
+         VT.getVectorElementType() == MVT::i32);
+
+  assert(VT.isFixedLengthVector());
+  MVT ContainerVT = getContainerForFixedLengthVector(DAG, VT, Subtarget);
+  SDValue Passthru = convertToScalableVector(
+      ContainerVT, DAG.getConstant(0, DL, VT), DAG, Subtarget);
+  Op0 = convertToScalableVector(ContainerVT, Op0, DAG, Subtarget);
+  Op1 = convertToScalableVector(ContainerVT, Op1, DAG, Subtarget);
+
+  auto [Mask, VL] = getDefaultVLOps(VT, ContainerVT, DL, DAG, Subtarget);
+  const unsigned Policy = RISCVVType::TAIL_AGNOSTIC | RISCVVType::MASK_AGNOSTIC;
+  SDValue PolicyOp = DAG.getTargetConstant(Policy, DL, Subtarget.getXLenVT());
+  SDValue LocalAccum = DAG.getNode(Opc, DL, ContainerVT,
+                                   {Op0, Op1, Passthru, Mask, VL, PolicyOp});
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s-barannikov wrote:

This fails node verification (#138381).
VDOT_VL node is declared with 5 operands in td file, but is created with 6 operands.


https://github.com/llvm/llvm-project/pull/137039