diff --git a/llvm/include/llvm/IR/ModuleSummaryIndex.h b/llvm/include/llvm/IR/ModuleSummaryIndex.h
--- a/llvm/include/llvm/IR/ModuleSummaryIndex.h
+++ b/llvm/include/llvm/IR/ModuleSummaryIndex.h
@@ -584,7 +584,7 @@
     // Indicate if a function must be an unreachable function.
     //
     // This bit is sufficient but not necessary;
-    // If this bit is on, the function must be unreachable;
+    // if this bit is on, the function must be regarded as unreachable;
     // if this bit is off, the function might be reachable or unreachable.
     unsigned MustBeUnreachable : 1;
 
diff --git a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
--- a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
+++ b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
@@ -238,11 +238,11 @@
 //
 // Note if this helper function returns true, `F` is guaranteed
 // to be unreachable; if it returns false, `F` might still
-// be unreachble but not detected by this helper function.
+// be unreachble but not covered by this helper function.
 static bool mustBeUnreachableFunction(const Function &F) {
   if (!F.empty()) {
     const BasicBlock &entryBlock = F.getEntryBlock();
-    // A function must be unreachable if its basic block
+    // A function must be unreachable if its entry block
     // ends with an 'unreachable'.
     if (!entryBlock.empty()) {
       const Instruction *inst = &(*entryBlock.rbegin());
@@ -521,9 +521,6 @@
       TypeCheckedLoadConstVCalls.takeVector(), std::move(ParamAccesses));
   if (NonRenamableLocal)
     CantBePromoted.insert(F.getGUID());
-  // errs() << "MM Going to add F " << F.getName() << " with global identifier
-  // as " << F.getGlobalIdentifier()
-  //        << " to global value summary\n";
   Index.addGlobalValueSummary(F, std::move(FuncSummary));
 }
 
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -8350,8 +8350,6 @@
   std::vector<ValueInfo> Refs;
   // Default is all-zeros (conservative values).
   FunctionSummary::FFlags FFlags = {};
-  // TODO(mingming):
-  // This is changed due to unreachable.
   if (parseToken(lltok::colon, "expected ':' here") ||
       parseToken(lltok::lparen, "expected '(' here") ||
       parseModuleReference(ModulePath) ||
@@ -8609,7 +8607,6 @@
         return true;
       FFlags.MustBeUnreachable = Val;
       break;
-    // TODO(handle unreachable here and other places).
     default:
       return error(Lex.getLoc(), "expected function flag type");
     }
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -6309,7 +6309,6 @@
     //                        numrefs, numrefs x valueid,
     //                        n x (valueid, offset)]
     case bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS: {
-
       unsigned ValueID = Record[0];
       uint64_t RawFlags = Record[1];
       GlobalVarSummary::GVarFlags GVF = getDecodedGVarFlags(Record[2]);
@@ -6349,6 +6348,7 @@
       unsigned NumRefs = Record[4];
       unsigned NumRORefs = 0, NumWORefs = 0;
       int RefListStartIndex = 5;
+
       if (Version >= 4) {
         RawFunFlags = Record[4];
         RefListStartIndex = 6;
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -63,7 +63,6 @@
 #include "llvm/Support/AtomicOrdering.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -3153,7 +3153,6 @@
 
 void AssemblyWriter::printFunctionSummary(const FunctionSummary *FS) {
   Out << ", insts: " << FS->instCount();
-  // Out << ", unreachable: " << FS->isUnreachableFunction();
   if (FS->fflags().anyFlagSet())
     Out << ", " << FS->fflags();
 
diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
--- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -563,7 +563,6 @@
       std::vector<VTableBits> &Bits,
       DenseMap<Metadata *, std::set<TypeMemberInfo>> &TypeIdMap);
 
-  // Caller doesn't guarantee that `ExportSummary` must be not nullptr.
   bool tryFindVirtualCallTargets(
       std::vector<VirtualCallTarget> &TargetsForSlot,
       const std::set<TypeMemberInfo> &TypeMemberInfos, uint64_t ByteOffset,
@@ -650,11 +649,16 @@
                 function_ref<OptimizationRemarkEmitter &(Function *)> OREGetter,
                 function_ref<DominatorTree &(Function &)> LookupDomTree);
 
-  // Returns true if the function is unreachable from all summaries.
+  // Returns true if the function is unreachable from reading function
+  // summaries.
   //
   // In particular, identifies a function as unreachable if and only if
-  // 1) All summaries are function summaries.
-  // 2) All function summaries indicate it's unreachable.
+  // 1) All summaries are live.
+  // 2) All summaries are function summaries.
+  // 3) All function summaries indicate it's unreachable.
+  //
+  // FIXME: When ExportSummary is absent or not expected to be present (e.g.,
+  // regular LTO), analyze function reachability from IR.
   static bool mustBeUnreachableFunction(Function *TheFn,
                                         ModuleSummaryIndex *ExportSummary,
                                         bool IsExported);
@@ -948,9 +952,19 @@
 bool DevirtModule::mustBeUnreachableFunction(Function *TheFn,
                                              ModuleSummaryIndex *ExportSummary,
                                              bool IsExported) {
-  // ExportSummary is absent. No sufficient information to determine
-  // if the function is reachable.
+  // ExportSummary is absent, so analyze IR directly.
   if (ExportSummary == nullptr) {
+    if (!TheFn->empty()) {
+      const BasicBlock &entryBlock = TheFn->getEntryBlock();
+      // A function must be unreachable if its basic block
+      // ends with an 'unreachable'.
+      if (!entryBlock.empty()) {
+        const Instruction *inst = &(*entryBlock.rbegin());
+        if (inst->getOpcode() == Instruction::Unreachable) {
+          return true;
+        }
+      }
+    }
     return false;
   }
   assert((TheFn != nullptr) && "Caller guarantees that TheFn is not nullptr");
@@ -969,8 +983,13 @@
       return false;
     }
     bool AllSummariesAreFunctionSummary = true;
+    bool AllSummariesAreLive = true;
     bool AllFunctionSummariesIndicateUnreachable = true;
     for (auto &Summary : TheFnVI.getSummaryList()) {
+      if (!Summary->isLive()) {
+        AllSummariesAreLive = false;
+        break;
+      }
       if (auto *FS = dyn_cast<FunctionSummary>(Summary.get())) {
         if (!FS->fflags().MustBeUnreachable) {
           AllFunctionSummariesIndicateUnreachable = false;
@@ -982,9 +1001,10 @@
       }
     }
     // Identifies a function as unreachable if and only if
-    // 1) All summaries are function summaries.
-    // 2) All function summaries indicate it's unreachable.
-    if (AllSummariesAreFunctionSummary &&
+    // 1) All summaries are live.
+    // 2) All summaries are function summaries.
+    // 3) All function summaries indicate it's unreachable.
+    if (AllSummariesAreLive && AllSummariesAreFunctionSummary &&
         AllFunctionSummariesIndicateUnreachable) {
       return true;
     }
@@ -1057,6 +1077,8 @@
     if (Fn->getName() == "__cxa_pure_virtual")
       continue;
 
+    // We can disregard unreachable functions as possible call targets, as
+    // unreachable functions shouldn't be called.
     if (mustBeUnreachableFunction(Fn, ExportSummary, IsExported)) {
       continue;
     }
@@ -1209,11 +1231,9 @@
   // See if the program contains a single implementation of this virtual
   // function.
   Function *TheFn = TargetsForSlot[0].Fn;
-  for (auto &&Target : TargetsForSlot) {
-    if (TheFn != Target.Fn) {
+  for (auto &&Target : TargetsForSlot)
+    if (TheFn != Target.Fn)
       return false;
-    }
-  }
 
   // If so, update each call site to call that implementation directly.
   if (RemarksEnabled)
@@ -2185,7 +2205,9 @@
   std::map<std::string, Function*> DevirtTargets;
   for (auto &S : CallSlots) {
 
-    // `precomputedIsExported`
+    // Compute whether a function should be exported or not to
+    // get its linkage type.
+    // Linkage type is used to compute a functions GUID.
     bool precomputedIsExported = false;
     VTableSlotInfo &vtableSlotInfo = S.second;
     if (vtableSlotInfo.CSInfo.isExported()) {
diff --git a/llvm/test/ThinLTO/X86/Inputs/d1.ll b/llvm/test/ThinLTO/X86/Inputs/d1.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/Inputs/d1.ll
@@ -0,0 +1,204 @@
+; ModuleID = '/usr/local/google/home/mingmingl/test/d1.cc'
+source_filename = "/usr/local/google/home/mingmingl/test/d1.cc"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%class.Derived = type { %class.Base }
+%class.Base = type { i32 (...)** }
+
+$_ZN7DerivedD2Ev = comdat any
+
+$_ZN7DerivedD0Ev = comdat any
+
+$__clang_call_terminate = comdat any
+
+$_ZN4BaseD2Ev = comdat any
+
+$_ZN4BaseD0Ev = comdat any
+
+$_ZTS4Base = comdat any
+
+$_ZTI4Base = comdat any
+
+$_ZTV4Base = comdat any
+
+@.str = private unnamed_addr constant [12 x i8] c"Derived::x\0A\00", align 1
+@_ZTV7Derived = hidden unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8* null, i8* bitcast ({ i8*, i8*, i8* }* @_ZTI7Derived to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7DerivedD2Ev to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7DerivedD0Ev to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7Derived1xEv to i8*)] }, align 8, !type !0, !type !1, !type !2, !type !3, !vcall_visibility !4
+@_ZTVN10__cxxabiv120__si_class_type_infoE = external dso_local global i8*
+@_ZTS7Derived = hidden constant [9 x i8] c"7Derived\00", align 1
+@_ZTVN10__cxxabiv117__class_type_infoE = external dso_local global i8*
+@_ZTS4Base = linkonce_odr hidden constant [6 x i8] c"4Base\00", comdat, align 1
+@_ZTI4Base = linkonce_odr hidden constant { i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv117__class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([6 x i8], [6 x i8]* @_ZTS4Base, i32 0, i32 0) }, comdat, align 8
+@_ZTI7Derived = hidden constant { i8*, i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv120__si_class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([9 x i8], [9 x i8]* @_ZTS7Derived, i32 0, i32 0), i8* bitcast ({ i8*, i8* }* @_ZTI4Base to i8*) }, align 8
+@.str.1 = private unnamed_addr constant [24 x i8] c"In Derived::~Derived()\0A\00", align 1
+@_ZTV4Base = linkonce_odr hidden unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8* null, i8* bitcast ({ i8*, i8* }* @_ZTI4Base to i8*), i8* bitcast (void (%class.Base*)* @_ZN4BaseD2Ev to i8*), i8* bitcast (void (%class.Base*)* @_ZN4BaseD0Ev to i8*), i8* bitcast (void ()* @__cxa_pure_virtual to i8*)] }, comdat, align 8, !type !0, !type !1, !vcall_visibility !4
+@.str.2 = private unnamed_addr constant [18 x i8] c"In Base::~Base()\0A\00", align 1
+
+; Function Attrs: mustprogress noinline optnone uwtable
+define hidden void @_ZN7Derived1xEv(%class.Derived* nonnull align 8 dereferenceable(8) %this) unnamed_addr #0 align 2 {
+entry:
+  %this.addr = alloca %class.Derived*, align 8
+  store %class.Derived* %this, %class.Derived** %this.addr, align 8
+  %this1 = load %class.Derived*, %class.Derived** %this.addr, align 8
+  %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str, i64 0, i64 0))
+  ret void
+}
+
+declare dso_local i32 @printf(i8*, ...) #1
+
+; Function Attrs: mustprogress noinline nounwind optnone uwtable
+define hidden void @_Z3fooP4Base(%class.Base* %b) #2 {
+entry:
+  %b.addr = alloca %class.Base*, align 8
+  store %class.Base* %b, %class.Base** %b.addr, align 8
+  %0 = load %class.Base*, %class.Base** %b.addr, align 8
+  %isnull = icmp eq %class.Base* %0, null
+  br i1 %isnull, label %delete.end, label %delete.notnull
+
+delete.notnull:                                   ; preds = %entry
+  %1 = bitcast %class.Base* %0 to void (%class.Base*)***
+  %vtable = load void (%class.Base*)**, void (%class.Base*)*** %1, align 8
+  %2 = bitcast void (%class.Base*)** %vtable to i8*
+  %3 = call i1 @llvm.type.test(i8* %2, metadata !"_ZTS4Base")
+  call void @llvm.assume(i1 %3)
+  %vfn = getelementptr inbounds void (%class.Base*)*, void (%class.Base*)** %vtable, i64 1
+  %4 = load void (%class.Base*)*, void (%class.Base*)** %vfn, align 8
+  call void %4(%class.Base* nonnull align 8 dereferenceable(8) %0) #9
+  br label %delete.end
+
+delete.end:                                       ; preds = %delete.notnull, %entry
+  ret void
+}
+
+; Function Attrs: nofree nosync nounwind readnone speculatable willreturn
+declare i1 @llvm.type.test(i8*, metadata) #3
+
+; Function Attrs: inaccessiblememonly nofree nosync nounwind willreturn
+declare void @llvm.assume(i1 noundef) #4
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr hidden void @_ZN7DerivedD2Ev(%class.Derived* nonnull align 8 dereferenceable(8) %this) unnamed_addr #5 comdat align 2 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
+entry:
+  %this.addr = alloca %class.Derived*, align 8
+  %exn.slot = alloca i8*, align 8
+  %ehselector.slot = alloca i32, align 4
+  store %class.Derived* %this, %class.Derived** %this.addr, align 8
+  %this1 = load %class.Derived*, %class.Derived** %this.addr, align 8
+  %0 = bitcast %class.Derived* %this1 to i32 (...)***
+  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV7Derived, i32 0, inrange i32 0, i32 2) to i32 (...)**), i32 (...)*** %0, align 8
+  %call = invoke i32 (i8*, ...) @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.1, i64 0, i64 0))
+          to label %invoke.cont unwind label %lpad
+
+invoke.cont:                                      ; preds = %entry
+  %1 = bitcast %class.Derived* %this1 to %class.Base*
+  call void @_ZN4BaseD2Ev(%class.Base* nonnull align 8 dereferenceable(8) %1) #9
+  ret void
+
+lpad:                                             ; preds = %entry
+  %2 = landingpad { i8*, i32 }
+          catch i8* null
+  %3 = extractvalue { i8*, i32 } %2, 0
+  store i8* %3, i8** %exn.slot, align 8
+  %4 = extractvalue { i8*, i32 } %2, 1
+  store i32 %4, i32* %ehselector.slot, align 4
+  %5 = bitcast %class.Derived* %this1 to %class.Base*
+  call void @_ZN4BaseD2Ev(%class.Base* nonnull align 8 dereferenceable(8) %5) #9
+  br label %terminate.handler
+
+terminate.handler:                                ; preds = %lpad
+  %exn = load i8*, i8** %exn.slot, align 8
+  call void @__clang_call_terminate(i8* %exn) #10
+  unreachable
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr hidden void @_ZN7DerivedD0Ev(%class.Derived* nonnull align 8 dereferenceable(8) %this) unnamed_addr #5 comdat align 2 {
+entry:
+  %this.addr = alloca %class.Derived*, align 8
+  store %class.Derived* %this, %class.Derived** %this.addr, align 8
+  %this1 = load %class.Derived*, %class.Derived** %this.addr, align 8
+  call void @_ZN7DerivedD2Ev(%class.Derived* nonnull align 8 dereferenceable(8) %this1) #9
+  %0 = bitcast %class.Derived* %this1 to i8*
+  call void @_ZdlPv(i8* %0) #11
+  ret void
+}
+
+declare dso_local i32 @__gxx_personality_v0(...)
+
+; Function Attrs: noinline noreturn nounwind
+define linkonce_odr hidden void @__clang_call_terminate(i8* %0) #6 comdat {
+  %2 = call i8* @__cxa_begin_catch(i8* %0) #9
+  call void @_ZSt9terminatev() #10
+  unreachable
+}
+
+declare dso_local i8* @__cxa_begin_catch(i8*)
+
+declare dso_local void @_ZSt9terminatev()
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr hidden void @_ZN4BaseD2Ev(%class.Base* nonnull align 8 dereferenceable(8) %this) unnamed_addr #5 comdat align 2 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
+entry:
+  %this.addr = alloca %class.Base*, align 8
+  store %class.Base* %this, %class.Base** %this.addr, align 8
+  %this1 = load %class.Base*, %class.Base** %this.addr, align 8
+  %0 = bitcast %class.Base* %this1 to i32 (...)***
+  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV4Base, i32 0, inrange i32 0, i32 2) to i32 (...)**), i32 (...)*** %0, align 8
+  %call = invoke i32 (i8*, ...) @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.2, i64 0, i64 0))
+          to label %invoke.cont unwind label %terminate.lpad
+
+invoke.cont:                                      ; preds = %entry
+  ret void
+
+terminate.lpad:                                   ; preds = %entry
+  %1 = landingpad { i8*, i32 }
+          catch i8* null
+  %2 = extractvalue { i8*, i32 } %1, 0
+  call void @__clang_call_terminate(i8* %2) #10
+  unreachable
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr hidden void @_ZN4BaseD0Ev(%class.Base* nonnull align 8 dereferenceable(8) %this) unnamed_addr #5 comdat align 2 {
+entry:
+  %this.addr = alloca %class.Base*, align 8
+  store %class.Base* %this, %class.Base** %this.addr, align 8
+  %this1 = load %class.Base*, %class.Base** %this.addr, align 8
+  call void @llvm.trap() #10
+  unreachable
+}
+
+declare dso_local void @__cxa_pure_virtual() unnamed_addr
+
+; Function Attrs: cold noreturn nounwind
+declare void @llvm.trap() #7
+
+; Function Attrs: nobuiltin nounwind
+declare dso_local void @_ZdlPv(i8*) #8
+
+attributes #0 = { mustprogress noinline optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { "frame-pointer"="all" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #2 = { mustprogress noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #3 = { nofree nosync nounwind readnone speculatable willreturn }
+attributes #4 = { inaccessiblememonly nofree nosync nounwind willreturn }
+attributes #5 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #6 = { noinline noreturn nounwind }
+attributes #7 = { cold noreturn nounwind }
+attributes #8 = { nobuiltin nounwind "frame-pointer"="all" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #9 = { nounwind }
+attributes #10 = { noreturn nounwind }
+attributes #11 = { builtin nounwind }
+
+!llvm.module.flags = !{!5, !6, !7, !8}
+!llvm.ident = !{!9}
+
+!0 = !{i64 16, !"_ZTS4Base"}
+!1 = !{i64 32, !"_ZTSM4BaseFvvE.virtual"}
+!2 = !{i64 16, !"_ZTS7Derived"}
+!3 = !{i64 32, !"_ZTSM7DerivedFvvE.virtual"}
+!4 = !{i64 1}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{i32 1, !"Virtual Function Elim", i32 0}
+!7 = !{i32 7, !"uwtable", i32 1}
+!8 = !{i32 7, !"frame-pointer", i32 2}
+!9 = !{!"clang version 14.0.0 (https://github.com/llvm/llvm-project.git f6ae8e8cc7f495dad86e97bd9bbd828f9079fc9b)"}
diff --git a/llvm/test/ThinLTO/X86/d.ll b/llvm/test/ThinLTO/X86/d.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/d.ll
@@ -0,0 +1,237 @@
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit %s -o %t-main.bc
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit %p/Inputs/d1.ll -o %t-foo.bc
+; RUN: llvm-lto2 run -save-temps %t-main.bc %t-foo.bc -pass-remarks=. -o %t \
+; RUN:   -whole-program-visibility \
+; RUN:   -r=%t-foo.bc,_ZN7Derived1xEv,pl \
+; RUN:   -r=%t-foo.bc,printf, \
+; RUN:   -r=%t-foo.bc,_Z3fooP4Base,pl \
+; RUN:   -r=%t-foo.bc,_ZN7DerivedD2Ev,pl \
+; RUN:   -r=%t-foo.bc,_ZN7DerivedD0Ev,pl \
+; RUN:   -r=%t-foo.bc,__gxx_personality_v0, \
+; RUN:   -r=%t-foo.bc,__clang_call_terminate,pl \
+; RUN:   -r=%t-foo.bc,__cxa_begin_catch, \
+; RUN:   -r=%t-foo.bc,_ZSt9terminatev, \
+; RUN:   -r=%t-foo.bc,_ZN4BaseD2Ev,pl \
+; RUN:   -r=%t-foo.bc,_ZN4BaseD0Ev,pl \
+; RUN:   -r=%t-foo.bc,__cxa_pure_virtual, \
+; RUN:   -r=%t-foo.bc,_ZdlPv, \
+; RUN:   -r=%t-foo.bc,_ZTV7Derived,l \
+; RUN:   -r=%t-foo.bc,_ZTVN10__cxxabiv120__si_class_type_infoE, \
+; RUN:   -r=%t-foo.bc,_ZTS7Derived,pl \
+; RUN:   -r=%t-foo.bc,_ZTVN10__cxxabiv117__class_type_infoE, \
+; RUN:   -r=%t-foo.bc,_ZTS4Base,pl \
+; RUN:   -r=%t-foo.bc,_ZTI4Base,pl \
+; RUN:   -r=%t-foo.bc,_ZTI7Derived,pl \
+; RUN:   -r=%t-foo.bc,_ZTV4Base,l \
+; RUN:   -r=%t-foo.bc,__cxa_pure_virtual, \
+; RUN:   -r=%t-foo.bc,_ZN7Derived1xEv, \
+; RUN:   -r=%t-foo.bc,_ZN7DerivedD2Ev, \
+; RUN:   -r=%t-foo.bc,_ZN7DerivedD0Ev, \
+; RUN:   -r=%t-foo.bc,_ZN4BaseD2Ev, \
+; RUN:   -r=%t-foo.bc,_ZN4BaseD0Ev, \
+; RUN:   -r=%t-foo.bc,_ZTV7Derived,pl \
+; RUN:   -r=%t-foo.bc,_ZTI4Base, \
+; RUN:   -r=%t-foo.bc,_ZTI7Derived, \
+; RUN:   -r=%t-foo.bc,_ZTV4Base,pl \
+; RUN:   -r=%t-main.bc,main,plx \
+; RUN:   -r=%t-main.bc,_Znwm,pl \
+; RUN:   -r=%t-main.bc,_ZN7DerivedC2Ev,pl \
+; RUN:   -r=%t-main.bc,__gxx_personality_v0, \
+; RUN:   -r=%t-main.bc,_ZdlPv, \
+; RUN:   -r=%t-main.bc,_Z3fooP4Base, \
+; RUN:   -r=%t-main.bc,_ZN4BaseC2Ev,pl \
+; RUN:   -r=%t-main.bc,_ZN4BaseD2Ev, \
+; RUN:   -r=%t-main.bc,_ZN4BaseD0Ev, \
+; RUN:   -r=%t-main.bc,__cxa_pure_virtual, \
+; RUN:   -r=%t-main.bc,printf, \
+; RUN:   -r=%t-main.bc,__clang_call_terminate, \
+; RUN:   -r=%t-main.bc,__cxa_begin_catch, \
+; RUN:   -r=%t-main.bc,_ZSt9terminatev, \
+; RUN:   -r=%t-main.bc,_ZTV7Derived, \
+; RUN:   -r=%t-main.bc,_ZTV4Base, \
+; RUN:   -r=%t-main.bc,_ZTVN10__cxxabiv117__class_type_infoE, \
+; RUN:   -r=%t-main.bc,_ZTS4Base, \
+; RUN:   -r=%t-main.bc,_ZTI4Base, \
+; RUN:   -r=%t-main.bc,__cxa_pure_virtual, \
+; RUN:   -r=%t-main.bc,_ZN4BaseD2Ev, \
+; RUN:   -r=%t-main.bc,_ZN4BaseD0Ev, \
+; RUN:   -r=%t-main.bc,_ZTV4Base, \
+; RUN:   -r=%t-main.bc,_ZTI4Base, 2>&1 | FileCheck %s --check-prefix=REMARK
+ 
+; REMARK-COUNT-1: single-impl: devirtualized a call to _ZN7DerivedD0Ev
+
+; ModuleID = 'd2.cc'
+source_filename = "d2.cc"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%class.Derived = type { %class.Base }
+%class.Base = type { i32 (...)** }
+
+$_ZN7DerivedC2Ev = comdat any
+
+$_ZN4BaseC2Ev = comdat any
+
+$_ZN4BaseD2Ev = comdat any
+
+$_ZN4BaseD0Ev = comdat any
+
+$__clang_call_terminate = comdat any
+
+$_ZTV4Base = comdat any
+
+$_ZTS4Base = comdat any
+
+$_ZTI4Base = comdat any
+
+@_ZTV7Derived = external dso_local unnamed_addr constant { [5 x i8*] }, align 8
+@_ZTV4Base = linkonce_odr hidden unnamed_addr constant { [5 x i8*] } { [5 x i8*] [i8* null, i8* bitcast ({ i8*, i8* }* @_ZTI4Base to i8*), i8* bitcast (void (%class.Base*)* @_ZN4BaseD2Ev to i8*), i8* bitcast (void (%class.Base*)* @_ZN4BaseD0Ev to i8*), i8* bitcast (void ()* @__cxa_pure_virtual to i8*)] }, comdat, align 8, !type !0, !type !1, !vcall_visibility !2
+@_ZTVN10__cxxabiv117__class_type_infoE = external dso_local global i8*
+@_ZTS4Base = linkonce_odr hidden constant [6 x i8] c"4Base\00", comdat, align 1
+@_ZTI4Base = linkonce_odr hidden constant { i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv117__class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([6 x i8], [6 x i8]* @_ZTS4Base, i32 0, i32 0) }, comdat, align 8
+@.str = private unnamed_addr constant [18 x i8] c"In Base::~Base()\0A\00", align 1
+
+; Function Attrs: mustprogress noinline norecurse optnone uwtable
+define hidden i32 @main() #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
+entry:
+  %d = alloca %class.Derived*, align 8
+  %exn.slot = alloca i8*, align 8
+  %ehselector.slot = alloca i32, align 4
+  %call = call noalias nonnull i8* @_Znwm(i64 8) #8
+  %0 = bitcast i8* %call to %class.Derived*
+  invoke void @_ZN7DerivedC2Ev(%class.Derived* nonnull align 8 dereferenceable(8) %0)
+          to label %invoke.cont unwind label %lpad
+
+invoke.cont:                                      ; preds = %entry
+  store %class.Derived* %0, %class.Derived** %d, align 8
+  %1 = load %class.Derived*, %class.Derived** %d, align 8
+  %2 = bitcast %class.Derived* %1 to %class.Base*
+  call void @_Z3fooP4Base(%class.Base* %2)
+  ret i32 0
+
+lpad:                                             ; preds = %entry
+  %3 = landingpad { i8*, i32 }
+          cleanup
+  %4 = extractvalue { i8*, i32 } %3, 0
+  store i8* %4, i8** %exn.slot, align 8
+  %5 = extractvalue { i8*, i32 } %3, 1
+  store i32 %5, i32* %ehselector.slot, align 4
+  call void @_ZdlPv(i8* %call) #9
+  br label %eh.resume
+
+eh.resume:                                        ; preds = %lpad
+  %exn = load i8*, i8** %exn.slot, align 8
+  %sel = load i32, i32* %ehselector.slot, align 4
+  %lpad.val = insertvalue { i8*, i32 } undef, i8* %exn, 0
+  %lpad.val1 = insertvalue { i8*, i32 } %lpad.val, i32 %sel, 1
+  resume { i8*, i32 } %lpad.val1
+}
+
+; Function Attrs: nobuiltin allocsize(0)
+declare dso_local nonnull i8* @_Znwm(i64) #1
+
+; Function Attrs: noinline optnone uwtable
+define linkonce_odr hidden void @_ZN7DerivedC2Ev(%class.Derived* nonnull align 8 dereferenceable(8) %this) unnamed_addr #2 comdat align 2 {
+entry:
+  %this.addr = alloca %class.Derived*, align 8
+  store %class.Derived* %this, %class.Derived** %this.addr, align 8
+  %this1 = load %class.Derived*, %class.Derived** %this.addr, align 8
+  %0 = bitcast %class.Derived* %this1 to %class.Base*
+  call void @_ZN4BaseC2Ev(%class.Base* nonnull align 8 dereferenceable(8) %0)
+  %1 = bitcast %class.Derived* %this1 to i32 (...)***
+  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV7Derived, i32 0, inrange i32 0, i32 2) to i32 (...)**), i32 (...)*** %1, align 8
+  ret void
+}
+
+declare dso_local i32 @__gxx_personality_v0(...)
+
+; Function Attrs: nobuiltin nounwind
+declare dso_local void @_ZdlPv(i8*) #3
+
+declare dso_local void @_Z3fooP4Base(%class.Base*) #4
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr hidden void @_ZN4BaseC2Ev(%class.Base* nonnull align 8 dereferenceable(8) %this) unnamed_addr #5 comdat align 2 {
+entry:
+  %this.addr = alloca %class.Base*, align 8
+  store %class.Base* %this, %class.Base** %this.addr, align 8
+  %this1 = load %class.Base*, %class.Base** %this.addr, align 8
+  %0 = bitcast %class.Base* %this1 to i32 (...)***
+  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV4Base, i32 0, inrange i32 0, i32 2) to i32 (...)**), i32 (...)*** %0, align 8
+  ret void
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr hidden void @_ZN4BaseD2Ev(%class.Base* nonnull align 8 dereferenceable(8) %this) unnamed_addr #5 comdat align 2 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
+entry:
+  %this.addr = alloca %class.Base*, align 8
+  store %class.Base* %this, %class.Base** %this.addr, align 8
+  %this1 = load %class.Base*, %class.Base** %this.addr, align 8
+  %0 = bitcast %class.Base* %this1 to i32 (...)***
+  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [5 x i8*] }, { [5 x i8*] }* @_ZTV4Base, i32 0, inrange i32 0, i32 2) to i32 (...)**), i32 (...)*** %0, align 8
+  %call = invoke i32 (i8*, ...) @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str, i64 0, i64 0))
+          to label %invoke.cont unwind label %terminate.lpad
+
+invoke.cont:                                      ; preds = %entry
+  ret void
+
+terminate.lpad:                                   ; preds = %entry
+  %1 = landingpad { i8*, i32 }
+          catch i8* null
+  %2 = extractvalue { i8*, i32 } %1, 0
+  call void @__clang_call_terminate(i8* %2) #10
+  unreachable
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr hidden void @_ZN4BaseD0Ev(%class.Base* nonnull align 8 dereferenceable(8) %this) unnamed_addr #5 comdat align 2 {
+entry:
+  %this.addr = alloca %class.Base*, align 8
+  store %class.Base* %this, %class.Base** %this.addr, align 8
+  %this1 = load %class.Base*, %class.Base** %this.addr, align 8
+  call void @llvm.trap() #10
+  unreachable
+}
+
+declare dso_local void @__cxa_pure_virtual() unnamed_addr
+
+declare dso_local i32 @printf(i8*, ...) #4
+
+; Function Attrs: noinline noreturn nounwind
+define linkonce_odr hidden void @__clang_call_terminate(i8* %0) #6 comdat {
+  %2 = call i8* @__cxa_begin_catch(i8* %0) #11
+  call void @_ZSt9terminatev() #10
+  unreachable
+}
+
+declare dso_local i8* @__cxa_begin_catch(i8*)
+
+declare dso_local void @_ZSt9terminatev()
+
+; Function Attrs: cold noreturn nounwind
+declare void @llvm.trap() #7
+
+attributes #0 = { mustprogress noinline norecurse optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { nobuiltin allocsize(0) "frame-pointer"="all" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #2 = { noinline optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #3 = { nobuiltin nounwind "frame-pointer"="all" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #4 = { "frame-pointer"="all" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #5 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #6 = { noinline noreturn nounwind }
+attributes #7 = { cold noreturn nounwind }
+attributes #8 = { builtin allocsize(0) }
+attributes #9 = { builtin nounwind }
+attributes #10 = { noreturn nounwind }
+attributes #11 = { nounwind }
+
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+!0 = !{i64 16, !"_ZTS4Base"}
+!1 = !{i64 32, !"_ZTSM4BaseFvvE.virtual"}
+!2 = !{i64 1}
+!3 = !{i32 1, !"wchar_size", i32 4}
+!4 = !{i32 1, !"Virtual Function Elim", i32 0}
+!5 = !{i32 7, !"uwtable", i32 1}
+!6 = !{i32 7, !"frame-pointer", i32 2}
+!7 = !{!"clang version 14.0.0 (https://github.com/llvm/llvm-project.git f6ae8e8cc7f495dad86e97bd9bbd828f9079fc9b)"}
diff --git a/llvm/tools/llvm-lto2/llvm-lto2.cpp b/llvm/tools/llvm-lto2/llvm-lto2.cpp
--- a/llvm/tools/llvm-lto2/llvm-lto2.cpp
+++ b/llvm/tools/llvm-lto2/llvm-lto2.cpp
@@ -229,7 +229,6 @@
         return 1;
       }
     }
-    //llvm::errs() << "Insert [" << std::string(FileName) << ", " << std::string(SymbolName) << "] into map\n";
     CommandLineResolutions[{std::string(FileName), std::string(SymbolName)}]
         .push_back(Res);
   }