diff --git a/llvm/include/llvm/Transforms/Utils/Local.h b/llvm/include/llvm/Transforms/Utils/Local.h
--- a/llvm/include/llvm/Transforms/Utils/Local.h
+++ b/llvm/include/llvm/Transforms/Utils/Local.h
@@ -342,9 +342,13 @@
 bool replaceAllDbgUsesWith(Instruction &From, Value &To, Instruction &DomPoint,
                            DominatorTree &DT);
 
-/// Remove all instructions from a basic block other than it's terminator
-/// and any present EH pad instructions.
-unsigned removeAllNonTerminatorAndEHPadInstructions(BasicBlock *BB);
+/// Remove all instructions from a basic block other than its terminator
+/// and any present EH pad instructions. Returns a pair where the first element
+/// is the number of instructions (excluding debug info instrinsics) that have
+/// been removed, and the second element is the number of debug info intrinsics
+/// that have been removed.
+std::pair<unsigned, unsigned>
+removeAllNonTerminatorAndEHPadInstructions(BasicBlock *BB);
 
 /// Insert an unreachable instruction before the specified
 /// instruction, making it and the rest of the code in the block dead.
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -3776,8 +3776,12 @@
     if (Visited.count(&BB))
       continue;
 
-    unsigned NumDeadInstInBB = removeAllNonTerminatorAndEHPadInstructions(&BB);
-    MadeIRChange |= NumDeadInstInBB > 0;
+    unsigned NumDeadInstInBB;
+    unsigned NumDeadDbgInstInBB;
+    std::tie(NumDeadInstInBB, NumDeadDbgInstInBB) =
+        removeAllNonTerminatorAndEHPadInstructions(&BB);
+
+    MadeIRChange |= NumDeadInstInBB + NumDeadDbgInstInBB > 0;
     NumDeadInst += NumDeadInstInBB;
   }
 
diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -1707,7 +1707,7 @@
       LLVM_DEBUG(dbgs() << "  BasicBlock Dead:" << BB);
 
       ++NumDeadBlocks;
-      NumInstRemoved += removeAllNonTerminatorAndEHPadInstructions(&BB);
+      NumInstRemoved += removeAllNonTerminatorAndEHPadInstructions(&BB).first;
 
       MadeChanges = true;
       continue;
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1919,8 +1919,10 @@
   return false;
 }
 
-unsigned llvm::removeAllNonTerminatorAndEHPadInstructions(BasicBlock *BB) {
+std::pair<unsigned, unsigned>
+llvm::removeAllNonTerminatorAndEHPadInstructions(BasicBlock *BB) {
   unsigned NumDeadInst = 0;
+  unsigned NumDeadDbgInst = 0;
   // Delete the instructions backwards, as it has a reduced likelihood of
   // having to update as many def-use and use-def chains.
   Instruction *EndInst = BB->getTerminator(); // Last not to be deleted.
@@ -1933,11 +1935,13 @@
       EndInst = Inst;
       continue;
     }
-    if (!isa<DbgInfoIntrinsic>(Inst))
+    if (isa<DbgInfoIntrinsic>(Inst))
+      ++NumDeadDbgInst;
+    else
       ++NumDeadInst;
     Inst->eraseFromParent();
   }
-  return NumDeadInst;
+  return {NumDeadInst, NumDeadDbgInst};
 }
 
 unsigned llvm::changeToUnreachable(Instruction *I, bool UseLLVMTrap,
diff --git a/llvm/test/Transforms/InstCombine/unreachable-dbg-info-modified.ll b/llvm/test/Transforms/InstCombine/unreachable-dbg-info-modified.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/unreachable-dbg-info-modified.ll
@@ -0,0 +1,41 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; When removing the llvm.dbg.value intrinsic in the unreachable block
+; InstCombine would incorrectly return a false Modified status.
+
+; CHECK: cond.true:
+; CHECK-NEXT: br label %cond.end
+
+define i32 @foo() !dbg !7 {
+entry:
+  br i1 false, label %cond.true, label %cond.end
+
+cond.true:
+  call void @llvm.dbg.value(metadata i32 undef, metadata !12, metadata !DIExpression()), !dbg !13
+  br label %cond.end
+
+cond.end:
+  ret i32 undef
+}
+
+declare void @llvm.dbg.value(metadata, metadata, metadata) #0
+
+attributes #0 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 12.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "foo.c", directory: "/")
+!2 = !{}
+!3 = !{i32 7, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!6 = !{!"clang version 12.0.0"}
+!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{!12, !12}
+!12 = !DILocalVariable(name: "bar", scope: !7, file: !1, line: 1, type: !10)
+!13 = !DILocation(line: 0, scope: !7)