[llvm] [RISCV] Support VLS for VCIX (PR #67289)

[Craig Topper via llvm-commits]

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@@ -8163,6 +8200,46 @@ SDValue RISCVTargetLowering::LowerINTRINSIC_W_CHAIN(SDValue Op,
     Results.push_back(Result.getValue(NF));
     return DAG.getMergeValues(Results, DL);
   }
+  case Intrinsic::riscv_sf_vc_v_x_se:
+  case Intrinsic::riscv_sf_vc_v_i_se:
+  case Intrinsic::riscv_sf_vc_v_xv_se:
+  case Intrinsic::riscv_sf_vc_v_iv_se:
+  case Intrinsic::riscv_sf_vc_v_vv_se:
+  case Intrinsic::riscv_sf_vc_v_fv_se:
+  case Intrinsic::riscv_sf_vc_v_xvv_se:
+  case Intrinsic::riscv_sf_vc_v_ivv_se:
+  case Intrinsic::riscv_sf_vc_v_vvv_se:
+  case Intrinsic::riscv_sf_vc_v_fvv_se:
+  case Intrinsic::riscv_sf_vc_v_xvw_se:
+  case Intrinsic::riscv_sf_vc_v_ivw_se:
+  case Intrinsic::riscv_sf_vc_v_vvw_se:
+  case Intrinsic::riscv_sf_vc_v_fvw_se: {
+    MVT VT = Op.getSimpleValueType();
+
+    if (!VT.isFixedLengthVector())
+      break;
+
+    SmallVector<SDValue, 6> Ops;
+    for (const SDValue &V : Op->op_values()) {
+      // Skip non-fixed vector operands.
+      if (!V.getValueType().isFixedLengthVector()) {
+        Ops.push_back(V);
+        continue;
+      }
+
+      MVT OpContainerVT =
+          getContainerForFixedLengthVector(V.getSimpleValueType());
+      Ops.push_back(convertToScalableVector(OpContainerVT, V, DAG, Subtarget));
+    }
+
+    SDLoc DL(Op);
+    MVT RetContainerVT = getContainerForFixedLengthVector(VT);
+    SDValue ScalableVector =
+        DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL, RetContainerVT, Ops);
+    SDValue FixedVector =
+        convertFromScalableVector(VT, ScalableVector, DAG, Subtarget);
+    return DAG.getMergeValues({FixedVector, Op.getOperand(0)}, DL);
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topperc wrote:

`Op.getOperand(0)` should be `ScalableVector.getValue(1)` after making `ScalableVector` have two results.

https://github.com/llvm/llvm-project/pull/67289