diff --git a/llvm/test/tools/llvm-nm/XCOFF/demangle.test b/llvm/test/tools/llvm-nm/XCOFF/demangle.test
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-nm/XCOFF/demangle.test
@@ -0,0 +1,40 @@
+## Test llvm-nm demangling of symbols for XCOFF object files.
+## Test following symbols:
+## 1. Empty name
+## 2. Name consisting solely of .
+## 3. Name starting with . that can't be demangled
+## 4. Name starting with . that can be demangled
+## 5. Name not starting with . that can't be demangled
+## 6. Name not starting with . that can be demangled
+
+# RUN: yaml2obj --docnum=1 %s -o %t.o
+# RUN: llvm-nm --demangle --format=just-symbols %t.o 2>&1 | FileCheck %s --check-prefix=NM-DEMANGLE --match-full-lines
+
+# NM-DEMANGLE:       {{$}}
+# NM-DEMANGLE-NEXT:  .
+# NM-DEMANGLE-NEXT:  ._5func1i
+# NM-DEMANGLE-NEXT:  .func1(int)
+# NM-DEMANGLE-NEXT:  L5func0v
+# NM-DEMANGLE-NEXT:  func0()
+
+--- !XCOFF
+FileHeader:
+  MagicNumber:       0x1DF
+Sections:
+  - Name:            .text
+    Flags:           [ STYP_TEXT ]
+  - Name:            .data
+    Flags:           [ STYP_DATA ]
+Symbols:
+  - Name:            ""
+    Section:         .text
+  - Name:            .
+    Section:         .text
+  - Name:            ._Z5func1i
+    Section:         .text
+  - Name:            ._5func1i
+    Section:         .text
+  - Name:            _ZL5func0v
+    Section:         .data
+  - Name:            L5func0v
+    Section:         .data
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
@@ -617,18 +617,30 @@
     outs() << format("   %02x", NType);
 }
 
-static Optional<std::string> demangle(const std::string &Name,
-                                      bool StripUnderscore) {
-  const char *Mangled = Name.c_str();
-  if (StripUnderscore && Mangled[0] == '_')
-    Mangled = Mangled + 1;
-
+static Optional<std::string> demangle(StringRef Name) {
   std::string Demangled;
-  if (nonMicrosoftDemangle(Mangled, Demangled))
+  if (nonMicrosoftDemangle(Name.str().c_str(), Demangled))
     return Demangled;
   return None;
 }
 
+static Optional<std::string> demangleXCOFF(StringRef Name) {
+  if (Name.empty() || Name[0] != '.')
+    return demangle(Name);
+
+  Name = Name.drop_front();
+  Optional<std::string> DemangledName = demangle(Name);
+  if (DemangledName)
+    return "." + *DemangledName;
+  return None;
+}
+
+static 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';
 }
@@ -717,7 +729,12 @@
     std::string Name = S.Name;
     MachOObjectFile *MachO = dyn_cast<MachOObjectFile>(&Obj);
     if (Demangle) {
-      if (Optional<std::string> Opt = demangle(S.Name, MachO))
+      function_ref<Optional<std::string>(StringRef)> Fn = ::demangle;
+      if (Obj.isXCOFF())
+        Fn = demangleXCOFF;
+      if (Obj.isMachO())
+        Fn = demangleMachO;
+      if (Optional<std::string> Opt = Fn(S.Name))
         Name = *Opt;
     }
     if (S.Sym.getRawDataRefImpl().p) {