Index: llvm/lib/Transforms/Utils/LoopUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -641,18 +641,17 @@
       }
 
     // After the loop has been deleted all the values defined and modified
-    // inside the loop are going to be unavailable.
-    // Since debug values in the loop have been deleted, inserting an undef
-    // dbg.value truncates the range of any dbg.value before the loop where the
-    // loop used to be. This is particularly important for constant values.
+    // inside the loop are going to be unavailable. Values computed in the
+    // loop will have been deleted, automatically causing their debug uses
+    // be be replaced with undef. Loop invariant values will still be available.
+    // Move dbg.values out the loop so that earlier location ranges are still
+    // terminated and loop invariant assignments are preserved.
     Instruction *InsertDbgValueBefore = ExitBlock->getFirstNonPHI();
     assert(InsertDbgValueBefore &&
            "There should be a non-PHI instruction in exit block, else these "
            "instructions will have no parent.");
-    for (auto *DVI : DeadDebugInst) {
-      DVI->setKillLocation();
+    for (auto *DVI : DeadDebugInst)
       DVI->moveBefore(InsertDbgValueBefore);
-    }
   }
 
   // Remove the block from the reference counting scheme, so that we can
Index: llvm/test/DebugInfo/Generic/assignment-tracking/loop-deletion/dead-loop.ll
===================================================================
--- llvm/test/DebugInfo/Generic/assignment-tracking/loop-deletion/dead-loop.ll
+++ llvm/test/DebugInfo/Generic/assignment-tracking/loop-deletion/dead-loop.ll
@@ -18,7 +18,7 @@
 ;; mistake.
 
 ; CHECK: for.end:
-; CHECK-NEXT: call void @llvm.dbg.assign(metadata i32 poison,{{.+}}, metadata !DIExpression({{.+}}), metadata ![[ID:[0-9]+]], metadata ptr %Counter, metadata !DIExpression())
+; CHECK-NEXT: call void @llvm.dbg.assign(metadata i32 undef,{{.+}}, metadata !DIExpression({{.+}}), metadata ![[ID:[0-9]+]], metadata ptr %Counter, metadata !DIExpression())
 ; CHECK-NEXT: store i32 2, ptr %Counter, align 4,{{.*}}!DIAssignID ![[ID]]
 
 define dso_local void @_Z3funv() local_unnamed_addr #0 !dbg !7 {
Index: llvm/test/Transforms/LoopDeletion/diundef.ll
===================================================================
--- llvm/test/Transforms/LoopDeletion/diundef.ll
+++ llvm/test/Transforms/LoopDeletion/diundef.ll
@@ -18,7 +18,7 @@
   %exitcond = icmp ne i32 %inc, 3, !dbg !23
   br i1 %exitcond, label %for.cond, label %for.end, !dbg !24, !llvm.loop !25
 
-; CHECK: call void @llvm.dbg.value(metadata i32 poison, metadata !16, metadata !DIExpression()), !dbg !17
+; CHECK: call void @llvm.dbg.value(metadata i32 undef, metadata !16, metadata !DIExpression()), !dbg !17
 ; CHECK-NEXT: %call = tail call i32 {{.*}} @patatino()
 for.end:                                          ; preds = %for.cond
   %call = tail call i32 (...) @patatino() #3, !dbg !27
Index: llvm/test/Transforms/LoopDeletion/over-defensive-undefing-dbg-values.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopDeletion/over-defensive-undefing-dbg-values.ll
@@ -0,0 +1,78 @@
+; RUN: opt -S %s -passes=loop-deletion | FileCheck %s
+
+;; static int foo(int Param) __attribute__((always_inline));
+;; static int foo(int Param) { return Param * Param * 2; }
+;;
+;; static int zero() __attribute__((always_inline));
+;; static int zero() { return 0; }
+;;
+;; void test() {
+;;   int Constant = 0;
+;;   for (int Index = zero(); Index < 0; ++Index) {
+;;     foo(Index);
+;;     Constant = 5;
+;;     foo(Index + 1);
+;;   }
+;; }
+;;
+;; Check that a loop invariant value in a dbg.value inside the dead
+;; loop is preserved.
+
+; CHECK-LABEL: for.end:
+; CHECK-NEXT:    @llvm.dbg.value({{.+}} undef, metadata ![[VAR1:[0-9]+]],{{.+}}), !dbg ![[DBG1:[0-9]+]]
+; CHECK-NEXT:    @llvm.dbg.value({{.+}} 5, metadata ![[VAR2:[0-9]+]],{{.+}}), !dbg ![[DBG2:[0-9]+]]
+
+; CHECK-DAG: ![[VAR1]] = !DILocalVariable(name: "Index"
+; CHECK-DAG: ![[VAR2]] = !DILocalVariable(name: "Constant"
+
+; CHECK-DAG: ![[DBG1]] = !DILocation(line: 0
+; CHECK-DAG: ![[DBG2]] = !DILocation(line: 0
+
+define dso_local void @test() !dbg !9 {
+entry:
+  call void @llvm.dbg.value(metadata i32 0, metadata !13, metadata !DIExpression()), !dbg !15
+  call void @llvm.dbg.value(metadata i32 0, metadata !16, metadata !DIExpression()), !dbg !18
+  br label %for.end, !dbg !19
+
+for.end:                                          ; preds = %entry
+  call void @llvm.dbg.value(metadata i32 undef, metadata !16, metadata !DIExpression()), !dbg !18
+  call void @llvm.dbg.value(metadata i32 5, metadata !13, metadata !DIExpression()), !dbg !15
+  ret void, !dbg !30
+}
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5, !6, !7}
+!llvm.ident = !{!8}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang version 17.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test", directory: "", checksumkind: CSK_MD5, checksum: "53f7b620ca60e4fc7af4e6e4cdac8eea")
+!2 = !{i32 2, !"CodeView", i32 1}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 2}
+!5 = !{i32 8, !"PIC Level", i32 2}
+!6 = !{i32 7, !"uwtable", i32 2}
+!7 = !{i32 1, !"MaxTLSAlign", i32 65536}
+!8 = !{!"clang version 17.0.0"}
+!9 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 7, type: !10, scopeLine: 7, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !12)
+!10 = !DISubroutineType(types: !11)
+!11 = !{null}
+!12 = !{}
+!13 = !DILocalVariable(name: "Constant", scope: !9, file: !1, line: 8, type: !14)
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DILocation(line: 0, scope: !9)
+!16 = !DILocalVariable(name: "Index", scope: !17, file: !1, line: 9, type: !14)
+!17 = distinct !DILexicalBlock(scope: !9, file: !1, line: 9)
+!18 = !DILocation(line: 0, scope: !17)
+!19 = !DILocation(line: 9, scope: !17)
+!21 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !22, scopeLine: 2, flags: DIFlagPrototyped, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !0, retainedNodes: !12)
+!22 = !DISubroutineType(types: !23)
+!23 = !{!14, !14}
+!24 = !DILocation(line: 0, scope: !21, inlinedAt: !25)
+!25 = distinct !DILocation(line: 10, scope: !26)
+!26 = distinct !DILexicalBlock(scope: !27, file: !1, line: 9)
+!27 = distinct !DILexicalBlock(scope: !17, file: !1, line: 9)
+!28 = !DILocation(line: 0, scope: !21, inlinedAt: !29)
+!29 = distinct !DILocation(line: 12, scope: !26)
+!30 = !DILocation(line: 14, scope: !9)