diff --git a/llvm/include/llvm/CodeGen/ISDOpcodes.h b/llvm/include/llvm/CodeGen/ISDOpcodes.h
index b3a2ced70e628..cdaa916548c25 100644
--- a/llvm/include/llvm/CodeGen/ISDOpcodes.h
+++ b/llvm/include/llvm/CodeGen/ISDOpcodes.h
@@ -655,8 +655,8 @@ enum NodeType {
 
   /// SCALAR_TO_VECTOR(VAL) - This represents the operation of loading a
   /// scalar value into element 0 of the resultant vector type.  The top
-  /// elements 1 to N-1 of the N-element vector are undefined.  The type
-  /// of the operand must match the vector element type, except when they
+  /// elements 1 to N-1 of the N-element vector are poison. The type of
+  /// the operand must match the vector element type, except when they
   /// are integer types.  In this case the operand is allowed to be wider
   /// than the vector element type, and is implicitly truncated to it.
   SCALAR_TO_VECTOR,
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index 6284ded3be922..c7790404c0de1 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -496,7 +496,7 @@ SDValue DAGTypeLegalizer::ScalarizeVecRes_LOAD(LoadSDNode *N) {
   SDValue Result = DAG.getLoad(
       ISD::UNINDEXED, N->getExtensionType(),
       N->getValueType(0).getVectorElementType(), SDLoc(N), N->getChain(),
-      N->getBasePtr(), DAG.getUNDEF(N->getBasePtr().getValueType()),
+      N->getBasePtr(), DAG.getPOISON(N->getBasePtr().getValueType()),
       N->getPointerInfo(), N->getMemoryVT().getVectorElementType(),
       N->getBaseAlign(), N->getMemOperand()->getFlags(), N->getAAInfo());
 
@@ -2186,7 +2186,7 @@ void DAGTypeLegalizer::SplitVecRes_ScalarOp(SDNode *N, SDValue &Lo,
   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
   Lo = DAG.getNode(N->getOpcode(), dl, LoVT, N->getOperand(0));
   if (N->getOpcode() == ISD::SCALAR_TO_VECTOR) {
-    Hi = DAG.getUNDEF(HiVT);
+    Hi = DAG.getPOISON(HiVT);
   } else {
     assert(N->getOpcode() == ISD::SPLAT_VECTOR && "Unexpected opcode");
     Hi = Lo;
@@ -2213,7 +2213,7 @@ void DAGTypeLegalizer::SplitVecRes_LOAD(LoadSDNode *LD, SDValue &Lo,
   ISD::LoadExtType ExtType = LD->getExtensionType();
   SDValue Ch = LD->getChain();
   SDValue Ptr = LD->getBasePtr();
-  SDValue Offset = DAG.getUNDEF(Ptr.getValueType());
+  SDValue Offset = DAG.getPOISON(Ptr.getValueType());
   EVT MemoryVT = LD->getMemoryVT();
   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
   AAMDNodes AAInfo = LD->getAAInfo();
@@ -2363,7 +2363,7 @@ void DAGTypeLegalizer::SplitVecRes_VP_LOAD_FF(VPLoadFFSDNode *LD, SDValue &Lo,
   Lo = DAG.getLoadFFVP(LoVT, dl, Ch, Ptr, MaskLo, EVLLo, MMO);
 
   // Fill the upper half with poison.
-  Hi = DAG.getUNDEF(HiVT);
+  Hi = DAG.getPOISON(HiVT);
 
   ReplaceValueWith(SDValue(LD, 1), Lo.getValue(1));
   ReplaceValueWith(SDValue(LD, 2), Lo.getValue(2));
@@ -3344,7 +3344,7 @@ void DAGTypeLegalizer::SplitVecRes_VP_REVERSE(SDNode *N, SDValue &Lo,
 
   SDValue TrueMask = DAG.getBoolConstant(true, DL, Mask.getValueType(), VT);
   SDValue Store = DAG.getStridedStoreVP(DAG.getEntryNode(), DL, Val, StorePtr,
-                                        DAG.getUNDEF(PtrVT), Stride, TrueMask,
+                                        DAG.getPOISON(PtrVT), Stride, TrueMask,
                                         EVL, MemVT, StoreMMO, ISD::UNINDEXED);
 
   SDValue Load = DAG.getLoadVP(VT, DL, Store, StackPtr, Mask, EVL, LoadMMO);
@@ -3387,14 +3387,16 @@ void DAGTypeLegalizer::SplitVecRes_VP_SPLICE(SDNode *N, SDValue &Lo,
 
   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, EVL1);
 
+  SDValue PoisonPtr = DAG.getPOISON(PtrVT);
+
   SDValue TrueMask = DAG.getBoolConstant(true, DL, Mask.getValueType(), VT);
-  SDValue StoreV1 = DAG.getStoreVP(DAG.getEntryNode(), DL, V1, StackPtr,
-                                   DAG.getUNDEF(PtrVT), TrueMask, EVL1,
-                                   V1.getValueType(), StoreMMO, ISD::UNINDEXED);
+  SDValue StoreV1 =
+      DAG.getStoreVP(DAG.getEntryNode(), DL, V1, StackPtr, PoisonPtr, TrueMask,
+                     EVL1, V1.getValueType(), StoreMMO, ISD::UNINDEXED);
 
   SDValue StoreV2 =
-      DAG.getStoreVP(StoreV1, DL, V2, StackPtr2, DAG.getUNDEF(PtrVT), TrueMask,
-                     EVL2, V2.getValueType(), StoreMMO, ISD::UNINDEXED);
+      DAG.getStoreVP(StoreV1, DL, V2, StackPtr2, PoisonPtr, TrueMask, EVL2,
+                     V2.getValueType(), StoreMMO, ISD::UNINDEXED);
 
   SDValue Load;
   if (Imm >= 0) {