diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
index c19cf71ba4c6a..c8c011d94e4a3 100644
--- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
@@ -662,6 +662,13 @@ static bool canCreateThunkFor(Function *F) {
   return true;
 }
 
+/// Copy metadata from one function to another.
+static void copyMetadataIfPresent(Function *From, Function *To, StringRef Key) {
+  if (MDNode *MD = From->getMetadata(Key)) {
+    To->setMetadata(Key, MD);
+  }
+}
+
 // Replace G with a simple tail call to bitcast(F). Also (unless
 // MergeFunctionsPDI holds) replace direct uses of G with bitcast(F),
 // delete G. Under MergeFunctionsPDI, we use G itself for creating
@@ -740,6 +747,9 @@ void MergeFunctions::writeThunk(Function *F, Function *G) {
   } else {
     NewG->copyAttributesFrom(G);
     NewG->takeName(G);
+    // Ensure CFI type metadata is propagated to the new function.
+    copyMetadataIfPresent(G, NewG, "type");
+    copyMetadataIfPresent(G, NewG, "kcfi_type");
     removeUsers(G);
     G->replaceAllUsesWith(NewG);
     G->eraseFromParent();
@@ -815,6 +825,9 @@ void MergeFunctions::mergeTwoFunctions(Function *F, Function *G) {
                                       F->getAddressSpace(), "", F->getParent());
     NewF->copyAttributesFrom(F);
     NewF->takeName(F);
+    // Ensure CFI type metadata is propagated to the new function.
+    copyMetadataIfPresent(F, NewF, "type");
+    copyMetadataIfPresent(F, NewF, "kcfi_type");
     removeUsers(F);
     F->replaceAllUsesWith(NewF);
 
diff --git a/llvm/test/Transforms/MergeFunc/cfi-thunk-merging.ll b/llvm/test/Transforms/MergeFunc/cfi-thunk-merging.ll
new file mode 100644
index 0000000000000..d35d777282730
--- /dev/null
+++ b/llvm/test/Transforms/MergeFunc/cfi-thunk-merging.ll
@@ -0,0 +1,210 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --include-generated-funcs --version 2
+;; Check the cases involving internal CFI instrumented functions where we do not expect functions to be merged.
+; RUN: opt -S -passes=mergefunc < %s | FileCheck %s
+; RUN: opt -S -passes=mergefunc,lowertypetests < %s | FileCheck --check-prefix=LOWERTYPETESTS %s
+
+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"
+
+@0 = private unnamed_addr constant { i16, i16, [12 x i8] } { i16 -1, i16 0, [12 x i8] c"'int (int)'\00" }
+
+; Function Attrs: noinline nounwind optnone
+define dso_local i32 @f(i32 noundef %arg) #0 !type !3 !type !4 {
+entry:
+  %arg.addr = alloca i32, align 4
+  %a = alloca i32, align 4
+  %b = alloca i32, align 4
+  store i32 %arg, ptr %arg.addr, align 4
+  store i32 0, ptr %b, align 4
+  %0 = load i32, ptr %arg.addr, align 4
+  %cmp = icmp sgt i32 %0, 0
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  store i32 1, ptr %a, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  %1 = load i32, ptr %a, align 4
+  %2 = load i32, ptr %b, align 4
+  %add = add nsw i32 %1, %2
+  ret i32 %add
+}
+
+; Function Attrs: noinline nounwind optnone
+define dso_local i32 @f_thunk(i32 noundef %arg) #0 !type !3 !type !4 {
+entry:
+  %arg.addr = alloca i32, align 4
+  %a = alloca i32, align 4
+  %b = alloca i32, align 4
+  store i32 %arg, ptr %arg.addr, align 4
+  store i32 0, ptr %b, align 4
+  %0 = load i32, ptr %arg.addr, align 4
+  %cmp = icmp sgt i32 %0, 0
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  store i32 1, ptr %a, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  %1 = load i32, ptr %a, align 4
+  %2 = load i32, ptr %b, align 4
+  %add = add nsw i32 %1, %2
+  ret i32 %add
+}
+
+; Function Attrs: noinline nounwind optnone
+define dso_local i32 @g(i32 noundef %b) #0 !type !3 !type !4 {
+entry:
+  %b.addr = alloca i32, align 4
+  %fp = alloca ptr, align 8
+  store i32 %b, ptr %b.addr, align 4
+  %0 = load i32, ptr %b.addr, align 4
+  %tobool = icmp ne i32 %0, 0
+  %1 = zext i1 %tobool to i64
+  %cond = select i1 %tobool, ptr @f, ptr @f_thunk
+  store ptr %cond, ptr %fp, align 8
+  %2 = load ptr, ptr %fp, align 8
+  %3 = call i1 @llvm.type.test(ptr %2, metadata !"_ZTSFiiE"), !nosanitize !5
+  br i1 %3, label %cont, label %trap, !nosanitize !5
+
+trap:                                             ; preds = %entry
+  call void @llvm.ubsantrap(i8 2) #3, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %entry
+  %4 = load i32, ptr %b.addr, align 4
+  %call = call i32 %2(i32 noundef %4)
+  ret i32 %call
+}
+
+; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
+declare i1 @llvm.type.test(ptr, metadata) #1
+
+; Function Attrs: cold noreturn nounwind
+declare void @llvm.ubsantrap(i8 immarg) #2
+
+attributes #0 = { noinline nounwind optnone "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+attributes #2 = { cold noreturn nounwind }
+attributes #3 = { noreturn nounwind }
+
+!llvm.module.flags = !{!0, !1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 4, !"CFI Canonical Jump Tables", i32 0}
+!3 = !{i64 0, !"_ZTSFiiE"}
+!4 = !{i64 0, !"_ZTSFiiE.generalized"}
+!5 = !{}
+; CHECK-LABEL: define dso_local i32 @f
+; CHECK-SAME: (i32 noundef [[ARG:%.*]]) #[[ATTR0:[0-9]+]] !type !2 !type !3 {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[ARG_ADDR:%.*]] = alloca i32, align 4
+; CHECK-NEXT:    [[A:%.*]] = alloca i32, align 4
+; CHECK-NEXT:    [[B:%.*]] = alloca i32, align 4
+; CHECK-NEXT:    store i32 [[ARG]], ptr [[ARG_ADDR]], align 4
+; CHECK-NEXT:    store i32 0, ptr [[B]], align 4
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[ARG_ADDR]], align 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[TMP0]], 0
+; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i32 1, ptr [[A]], align 4
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    [[TMP1:%.*]] = load i32, ptr [[A]], align 4
+; CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr [[B]], align 4
+; CHECK-NEXT:    [[ADD:%.*]] = add nsw i32 [[TMP1]], [[TMP2]]
+; CHECK-NEXT:    ret i32 [[ADD]]
+;
+;
+; CHECK-LABEL: define dso_local i32 @g
+; CHECK-SAME: (i32 noundef [[B:%.*]]) #[[ATTR0]] !type !2 !type !3 {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[B_ADDR:%.*]] = alloca i32, align 4
+; CHECK-NEXT:    [[FP:%.*]] = alloca ptr, align 8
+; CHECK-NEXT:    store i32 [[B]], ptr [[B_ADDR]], align 4
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[B_ADDR]], align 4
+; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp ne i32 [[TMP0]], 0
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i1 [[TOBOOL]] to i64
+; CHECK-NEXT:    [[COND:%.*]] = select i1 [[TOBOOL]], ptr @f, ptr @f_thunk
+; CHECK-NEXT:    store ptr [[COND]], ptr [[FP]], align 8
+; CHECK-NEXT:    [[TMP2:%.*]] = load ptr, ptr [[FP]], align 8
+; CHECK-NEXT:    [[TMP3:%.*]] = call i1 @llvm.type.test(ptr [[TMP2]], metadata !"_ZTSFiiE"), !nosanitize !4
+; CHECK-NEXT:    br i1 [[TMP3]], label [[CONT:%.*]], label [[TRAP:%.*]], !nosanitize !4
+; CHECK:       trap:
+; CHECK-NEXT:    call void @llvm.ubsantrap(i8 2) #[[ATTR3:[0-9]+]], !nosanitize !4
+; CHECK-NEXT:    unreachable, !nosanitize !4
+; CHECK:       cont:
+; CHECK-NEXT:    [[TMP4:%.*]] = load i32, ptr [[B_ADDR]], align 4
+; CHECK-NEXT:    [[CALL:%.*]] = call i32 [[TMP2]](i32 noundef [[TMP4]])
+; CHECK-NEXT:    ret i32 [[CALL]]
+;
+;
+; CHECK-LABEL: define dso_local i32 @f_thunk
+; CHECK-SAME: (i32 noundef [[TMP0:%.*]]) #[[ATTR0]] !type !2 {
+; CHECK-NEXT:    [[TMP2:%.*]] = tail call i32 @f(i32 noundef [[TMP0]]) #[[ATTR0]]
+; CHECK-NEXT:    ret i32 [[TMP2]]
+;
+;
+; LOWERTYPETESTS-LABEL: define dso_local i32 @f
+; LOWERTYPETESTS-SAME: (i32 noundef [[ARG:%.*]]) #[[ATTR0:[0-9]+]] !type !2 !type !3 {
+; LOWERTYPETESTS-NEXT:  entry:
+; LOWERTYPETESTS-NEXT:    [[ARG_ADDR:%.*]] = alloca i32, align 4
+; LOWERTYPETESTS-NEXT:    [[A:%.*]] = alloca i32, align 4
+; LOWERTYPETESTS-NEXT:    [[B:%.*]] = alloca i32, align 4
+; LOWERTYPETESTS-NEXT:    store i32 [[ARG]], ptr [[ARG_ADDR]], align 4
+; LOWERTYPETESTS-NEXT:    store i32 0, ptr [[B]], align 4
+; LOWERTYPETESTS-NEXT:    [[TMP0:%.*]] = load i32, ptr [[ARG_ADDR]], align 4
+; LOWERTYPETESTS-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[TMP0]], 0
+; LOWERTYPETESTS-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; LOWERTYPETESTS:       if.then:
+; LOWERTYPETESTS-NEXT:    store i32 1, ptr [[A]], align 4
+; LOWERTYPETESTS-NEXT:    br label [[IF_END]]
+; LOWERTYPETESTS:       if.end:
+; LOWERTYPETESTS-NEXT:    [[TMP1:%.*]] = load i32, ptr [[A]], align 4
+; LOWERTYPETESTS-NEXT:    [[TMP2:%.*]] = load i32, ptr [[B]], align 4
+; LOWERTYPETESTS-NEXT:    [[ADD:%.*]] = add nsw i32 [[TMP1]], [[TMP2]]
+; LOWERTYPETESTS-NEXT:    ret i32 [[ADD]]
+;
+;
+; LOWERTYPETESTS-LABEL: define dso_local i32 @g
+; LOWERTYPETESTS-SAME: (i32 noundef [[B:%.*]]) #[[ATTR0]] !type !2 !type !3 {
+; LOWERTYPETESTS-NEXT:  entry:
+; LOWERTYPETESTS-NEXT:    [[B_ADDR:%.*]] = alloca i32, align 4
+; LOWERTYPETESTS-NEXT:    [[FP:%.*]] = alloca ptr, align 8
+; LOWERTYPETESTS-NEXT:    store i32 [[B]], ptr [[B_ADDR]], align 4
+; LOWERTYPETESTS-NEXT:    [[TMP0:%.*]] = load i32, ptr [[B_ADDR]], align 4
+; LOWERTYPETESTS-NEXT:    [[TOBOOL:%.*]] = icmp ne i32 [[TMP0]], 0
+; LOWERTYPETESTS-NEXT:    [[TMP1:%.*]] = zext i1 [[TOBOOL]] to i64
+; LOWERTYPETESTS-NEXT:    [[COND:%.*]] = select i1 [[TOBOOL]], ptr @.cfi.jumptable, ptr getelementptr inbounds ([2 x [8 x i8]], ptr @.cfi.jumptable, i64 0, i64 1)
+; LOWERTYPETESTS-NEXT:    store ptr [[COND]], ptr [[FP]], align 8
+; LOWERTYPETESTS-NEXT:    [[TMP2:%.*]] = load ptr, ptr [[FP]], align 8
+; LOWERTYPETESTS-NEXT:    [[TMP3:%.*]] = ptrtoint ptr [[TMP2]] to i64
+; LOWERTYPETESTS-NEXT:    [[TMP4:%.*]] = sub i64 [[TMP3]], ptrtoint (ptr @.cfi.jumptable to i64)
+; LOWERTYPETESTS-NEXT:    [[TMP5:%.*]] = lshr i64 [[TMP4]], 3
+; LOWERTYPETESTS-NEXT:    [[TMP6:%.*]] = shl i64 [[TMP4]], 61
+; LOWERTYPETESTS-NEXT:    [[TMP7:%.*]] = or i64 [[TMP5]], [[TMP6]]
+; LOWERTYPETESTS-NEXT:    [[TMP8:%.*]] = icmp ule i64 [[TMP7]], 1
+; LOWERTYPETESTS-NEXT:    br i1 [[TMP8]], label [[CONT:%.*]], label [[TRAP:%.*]], !nosanitize !4
+; LOWERTYPETESTS:       trap:
+; LOWERTYPETESTS-NEXT:    call void @llvm.ubsantrap(i8 2) #[[ATTR4:[0-9]+]], !nosanitize !4
+; LOWERTYPETESTS-NEXT:    unreachable, !nosanitize !4
+; LOWERTYPETESTS:       cont:
+; LOWERTYPETESTS-NEXT:    [[TMP9:%.*]] = load i32, ptr [[B_ADDR]], align 4
+; LOWERTYPETESTS-NEXT:    [[CALL:%.*]] = call i32 [[TMP2]](i32 noundef [[TMP9]])
+; LOWERTYPETESTS-NEXT:    ret i32 [[CALL]]
+;
+;
+; LOWERTYPETESTS-LABEL: define dso_local i32 @f_thunk
+; LOWERTYPETESTS-SAME: (i32 noundef [[TMP0:%.*]]) #[[ATTR0]] !type !2 {
+; LOWERTYPETESTS-NEXT:    [[TMP2:%.*]] = tail call i32 @f(i32 noundef [[TMP0]]) #[[ATTR0]]
+; LOWERTYPETESTS-NEXT:    ret i32 [[TMP2]]
+;
+;
+; LOWERTYPETESTS-LABEL: define private void @.cfi.jumptable
+; LOWERTYPETESTS-SAME: () #[[ATTR3:[0-9]+]] align 8 {
+; LOWERTYPETESTS-NEXT:  entry:
+; LOWERTYPETESTS-NEXT:    call void asm sideeffect "jmp ${0:c}@plt\0Aint3\0Aint3\0Aint3\0Ajmp ${1:c}@plt\0Aint3\0Aint3\0Aint3\0A", "s,s"(ptr @f, ptr @f_thunk)
+; LOWERTYPETESTS-NEXT:    unreachable
+;