diff --git a/llvm/lib/Demangle/Demangle.cpp b/llvm/lib/Demangle/Demangle.cpp
--- a/llvm/lib/Demangle/Demangle.cpp
+++ b/llvm/lib/Demangle/Demangle.cpp
@@ -27,6 +27,10 @@
       nonMicrosoftDemangle(MangledName.substr(1), Result))
     return Result;
 
+  if (starts_with(MangledName, '.') &&
+      nonMicrosoftDemangle(MangledName.substr(1), Result))
+    return "." + Result;
+
   if (char *Demangled = microsoftDemangle(MangledName, nullptr, nullptr)) {
     Result = Demangled;
     std::free(Demangled);
diff --git a/llvm/tools/llvm-nm/llvm-nm.cpp b/llvm/tools/llvm-nm/llvm-nm.cpp
--- a/llvm/tools/llvm-nm/llvm-nm.cpp
+++ b/llvm/tools/llvm-nm/llvm-nm.cpp
@@ -629,30 +629,6 @@
     outs() << format("   %02x", NType);
 }
 
-static std::optional<std::string> demangle(StringRef Name) {
-  std::string Demangled;
-  if (nonMicrosoftDemangle(Name, Demangled))
-    return Demangled;
-  return std::nullopt;
-}
-
-static std::optional<std::string> demangleXCOFF(StringRef Name) {
-  if (Name.empty() || Name[0] != '.')
-    return demangle(Name);
-
-  Name = Name.drop_front();
-  std::optional<std::string> DemangledName = demangle(Name);
-  if (DemangledName)
-    return "." + *DemangledName;
-  return std::nullopt;
-}
-
-static std::optional<std::string> demangleMachO(StringRef Name) {
-  if (!Name.empty() && Name[0] == '_')
-    Name = Name.drop_front();
-  return demangle(Name);
-}
-
 static bool symbolIsDefined(const NMSymbol &Sym) {
   return Sym.TypeChar != 'U' && Sym.TypeChar != 'w' && Sym.TypeChar != 'v';
 }
@@ -822,15 +798,8 @@
 
     std::string Name = S.Name;
     MachOObjectFile *MachO = dyn_cast<MachOObjectFile>(&Obj);
-    if (Demangle) {
-      function_ref<std::optional<std::string>(StringRef)> Fn = ::demangle;
-      if (Obj.isXCOFF())
-        Fn = demangleXCOFF;
-      if (Obj.isMachO())
-        Fn = demangleMachO;
-      if (std::optional<std::string> Opt = Fn(S.Name))
-        Name = *Opt;
-    }
+    if (Demangle)
+      Name = llvm::demangle(Name);
 
     if (PrintFileName)
       writeFileName(outs(), ArchiveName, ArchitectureName);