Index: llvm/include/llvm/IR/IntrinsicInst.h
===================================================================
--- llvm/include/llvm/IR/IntrinsicInst.h
+++ llvm/include/llvm/IR/IntrinsicInst.h
@@ -267,7 +267,7 @@
            getIntrinsicID() != Intrinsic::dbg_assign;
   }
 
-  void setUndef() {
+  void setKillLocation() {
     // TODO: When/if we remove duplicate values from DIArgLists, we don't need
     // this set anymore.
     SmallPtrSet<Value *, 4> RemovedValues;
@@ -279,7 +279,7 @@
     }
   }
 
-  bool isUndef() const {
+  bool isKillLocation() const {
     // Check for "kill" sentinel values.
     // Non-variadic: empty metadata.
     if (!hasArgList() && isa<MDNode>(getRawLocation()))
Index: llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
===================================================================
--- llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
+++ llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
@@ -2107,11 +2107,9 @@
         continue;
       // Wrapper to get a single value (or undef) from DVI.
       auto GetValue = [DVI]() -> Value * {
-        // Conditions for undef: Any operand undef, zero operands or single
-        // operand is nullptr. We also can't handle variadic DIExpressions yet.
-        // Some of those conditions don't have a type we can pick for
-        // undef. Use i32.
-        if (DVI->isUndef() || DVI->getValue() == nullptr || DVI->hasArgList())
+        // We can't handle variadic DIExpressions yet so treat those as
+        // kill locations.
+        if (DVI->isKillLocation() || DVI->hasArgList())
           return UndefValue::get(Type::getInt32Ty(DVI->getContext()));
         return DVI->getValue();
       };
Index: llvm/lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -8328,7 +8328,7 @@
               dbgs()
               << "Unable to find valid location for Debug Value, undefing:\n"
               << *DVI);
-          DVI->setUndef();
+          DVI->setKillLocation();
           break;
         }
 
Index: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -6389,7 +6389,7 @@
                        llvm::PHINode *LSRInductionVar, DVIRecoveryRec &DVIRec,
                        const SCEV *SCEVInductionVar,
                        SCEVDbgValueBuilder IterCountExpr) {
-  if (!DVIRec.DVI->isUndef())
+  if (!DVIRec.DVI->isKillLocation())
     return false;
 
   // LSR may have caused several changes to the dbg.value in the failed salvage
@@ -6539,7 +6539,7 @@
         continue;
       // Ensure that if any location op is undef that the dbg.vlue is not
       // cached.
-      if (DVI->isUndef())
+      if (DVI->isKillLocation())
         continue;
 
       // Check that the location op SCEVs are suitable for translation to
@@ -6547,9 +6547,6 @@
       const auto &HasTranslatableLocationOps =
           [&](const DbgValueInst *DVI) -> bool {
         for (const auto LocOp : DVI->location_ops()) {
-          if (!LocOp)
-            return false;
-
           if (!SE.isSCEVable(LocOp->getType()))
             return false;
 
Index: llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -502,8 +502,8 @@
     bool IsDbgValueKind = (!DAI || at::getAssignmentInsts(DAI).empty());
     DebugVariable Aggregate = GetAggregateVariable(DVI);
     if (!SeenDefForAggregate.contains(Aggregate)) {
-      bool IsUndef = DVI->isUndef() && IsDbgValueKind;
-      if (!IsUndef) {
+      bool IsKill = DVI->isKillLocation() && IsDbgValueKind;
+      if (!IsKill) {
         SeenDefForAggregate.insert(Aggregate);
       } else if (DAI) {
         ToBeRemoved.push_back(DAI);
Index: llvm/lib/Transforms/Utils/Debugify.cpp
===================================================================
--- llvm/lib/Transforms/Utils/Debugify.cpp
+++ llvm/lib/Transforms/Utils/Debugify.cpp
@@ -345,7 +345,7 @@
             if (I.getDebugLoc().getInlinedAt())
               continue;
             // Skip undef values.
-            if (DVI->isUndef())
+            if (DVI->isKillLocation())
               continue;
 
             auto *Var = DVI->getVariable();
@@ -588,7 +588,7 @@
             if (I.getDebugLoc().getInlinedAt())
               continue;
             // Skip undef values.
-            if (DVI->isUndef())
+            if (DVI->isKillLocation())
               continue;
 
             auto *Var = DVI->getVariable();
Index: llvm/lib/Transforms/Utils/LoopUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -638,7 +638,7 @@
            "There should be a non-PHI instruction in exit block, else these "
            "instructions will have no parent.");
     for (auto *DVI : DeadDebugInst) {
-      DVI->setUndef();
+      DVI->setKillLocation();
       DVI->moveBefore(InsertDbgValueBefore);
     }
   }
Index: llvm/unittests/IR/DebugInfoTest.cpp
===================================================================
--- llvm/unittests/IR/DebugInfoTest.cpp
+++ llvm/unittests/IR/DebugInfoTest.cpp
@@ -228,7 +228,7 @@
   Instruction *DbgDeclare = &F.front().front();
   ASSERT_TRUE(isa<DbgDeclareInst>(DbgDeclare));
   // Check that this form counts as a "no location" marker.
-  EXPECT_TRUE(DbgDeclare->isUndef());
+  EXPECT_TRUE(DbgDeclare->isKillLocation());
 }
 
 TEST(DIBuiler, CreateFile) {