diff --git a/llvm/include/llvm/CodeGen/ISDOpcodes.h b/llvm/include/llvm/CodeGen/ISDOpcodes.h
--- a/llvm/include/llvm/CodeGen/ISDOpcodes.h
+++ b/llvm/include/llvm/CodeGen/ISDOpcodes.h
@@ -1363,7 +1363,7 @@
 std::optional<unsigned> getBaseOpcodeForVP(unsigned Opcode, bool hasFPExcept);
 
 /// Translate this non-VP Opcode to its corresponding VP Opcode.
-unsigned getVPForBaseOpcode(unsigned Opcode);
+std::optional<unsigned> getVPForBaseOpcode(unsigned Opcode);
 
 //===--------------------------------------------------------------------===//
 /// MemIndexedMode enum - This enum defines the load / store indexed
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -934,62 +934,63 @@
   // SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT) { return
   // DAG.getNode(Opcode, DL, VT); }
   SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue Operand) {
-    unsigned VPOpcode = ISD::getVPForBaseOpcode(Opcode);
-    assert(ISD::getVPMaskIdx(VPOpcode) == 1 &&
-           ISD::getVPExplicitVectorLengthIdx(VPOpcode) == 2);
-    return DAG.getNode(VPOpcode, DL, VT,
+    auto VPOpcode = ISD::getVPForBaseOpcode(Opcode);
+    assert(VPOpcode.has_value() && ISD::getVPMaskIdx(*VPOpcode) == 1 &&
+           ISD::getVPExplicitVectorLengthIdx(*VPOpcode) == 2);
+    return DAG.getNode(*VPOpcode, DL, VT,
                        {Operand, RootMaskOp, RootVectorLenOp});
   }
 
   SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
                   SDValue N2) {
-    unsigned VPOpcode = ISD::getVPForBaseOpcode(Opcode);
-    assert(ISD::getVPMaskIdx(VPOpcode) == 2 &&
-           ISD::getVPExplicitVectorLengthIdx(VPOpcode) == 3);
-    return DAG.getNode(VPOpcode, DL, VT,
+    auto VPOpcode = ISD::getVPForBaseOpcode(Opcode);
+    assert(VPOpcode.has_value() && ISD::getVPMaskIdx(*VPOpcode) == 2 &&
+           ISD::getVPExplicitVectorLengthIdx(*VPOpcode) == 3);
+    return DAG.getNode(*VPOpcode, DL, VT,
                        {N1, N2, RootMaskOp, RootVectorLenOp});
   }
 
   SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
                   SDValue N2, SDValue N3) {
-    unsigned VPOpcode = ISD::getVPForBaseOpcode(Opcode);
-    assert(ISD::getVPMaskIdx(VPOpcode) == 3 &&
-           ISD::getVPExplicitVectorLengthIdx(VPOpcode) == 4);
-    return DAG.getNode(VPOpcode, DL, VT,
+    auto VPOpcode = ISD::getVPForBaseOpcode(Opcode);
+    assert(VPOpcode.has_value() && ISD::getVPMaskIdx(*VPOpcode) == 3 &&
+           ISD::getVPExplicitVectorLengthIdx(*VPOpcode) == 4);
+    return DAG.getNode(*VPOpcode, DL, VT,
                        {N1, N2, N3, RootMaskOp, RootVectorLenOp});
   }
 
   SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue Operand,
                   SDNodeFlags Flags) {
-    unsigned VPOpcode = ISD::getVPForBaseOpcode(Opcode);
-    assert(ISD::getVPMaskIdx(VPOpcode) == 1 &&
-           ISD::getVPExplicitVectorLengthIdx(VPOpcode) == 2);
-    return DAG.getNode(VPOpcode, DL, VT, {Operand, RootMaskOp, RootVectorLenOp},
-                       Flags);
+    auto VPOpcode = ISD::getVPForBaseOpcode(Opcode);
+    assert(VPOpcode.has_value() && ISD::getVPMaskIdx(*VPOpcode) == 1 &&
+           ISD::getVPExplicitVectorLengthIdx(*VPOpcode) == 2);
+    return DAG.getNode(*VPOpcode, DL, VT,
+                       {Operand, RootMaskOp, RootVectorLenOp}, Flags);
   }
 
   SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
                   SDValue N2, SDNodeFlags Flags) {
-    unsigned VPOpcode = ISD::getVPForBaseOpcode(Opcode);
-    assert(ISD::getVPMaskIdx(VPOpcode) == 2 &&
-           ISD::getVPExplicitVectorLengthIdx(VPOpcode) == 3);
-    return DAG.getNode(VPOpcode, DL, VT, {N1, N2, RootMaskOp, RootVectorLenOp},
+    auto VPOpcode = ISD::getVPForBaseOpcode(Opcode);
+    assert(VPOpcode.has_value() && ISD::getVPMaskIdx(*VPOpcode) == 2 &&
+           ISD::getVPExplicitVectorLengthIdx(*VPOpcode) == 3);
+    return DAG.getNode(*VPOpcode, DL, VT, {N1, N2, RootMaskOp, RootVectorLenOp},
                        Flags);
   }
 
   SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
                   SDValue N2, SDValue N3, SDNodeFlags Flags) {
-    unsigned VPOpcode = ISD::getVPForBaseOpcode(Opcode);
-    assert(ISD::getVPMaskIdx(VPOpcode) == 3 &&
-           ISD::getVPExplicitVectorLengthIdx(VPOpcode) == 4);
-    return DAG.getNode(VPOpcode, DL, VT,
+    auto VPOpcode = ISD::getVPForBaseOpcode(Opcode);
+    assert(VPOpcode.has_value() && ISD::getVPMaskIdx(*VPOpcode) == 3 &&
+           ISD::getVPExplicitVectorLengthIdx(*VPOpcode) == 4);
+    return DAG.getNode(*VPOpcode, DL, VT,
                        {N1, N2, N3, RootMaskOp, RootVectorLenOp}, Flags);
   }
 
   bool isOperationLegalOrCustom(unsigned Op, EVT VT,
                                 bool LegalOnly = false) const {
-    unsigned VPOp = ISD::getVPForBaseOpcode(Op);
-    return TLI.isOperationLegalOrCustom(VPOp, VT, LegalOnly);
+    auto VPOp = ISD::getVPForBaseOpcode(Op);
+    assert(VPOp.has_value());
+    return TLI.isOperationLegalOrCustom(*VPOp, VT, LegalOnly);
   }
 };
 
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -531,10 +531,10 @@
   return std::nullopt;
 }
 
-unsigned ISD::getVPForBaseOpcode(unsigned Opcode) {
+std::optional<unsigned> ISD::getVPForBaseOpcode(unsigned Opcode) {
   switch (Opcode) {
   default:
-    llvm_unreachable("can not translate this Opcode to VP.");
+    return std::nullopt;
 #define BEGIN_REGISTER_VP_SDNODE(VPOPC, ...) break;
 #define VP_PROPERTY_FUNCTIONAL_SDOPC(SDOPC) case ISD::SDOPC:
 #define END_REGISTER_VP_SDNODE(VPOPC) return ISD::VPOPC;