diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -554,7 +554,7 @@
   NormalizedValuesScope<"FrontendOptions">,
   NormalizedValues<["ARCMT_Check", "ARCMT_Modify", "ARCMT_Migrate"]>,
   MarshallingInfoString<"FrontendOpts.ARCMTAction", "ARCMT_None">,
-  AutoNormalizeEnumJoined;
+  AutoNormalizeEnum;
 def print_stats : Flag<["-"], "print-stats">,
   HelpText<"Print performance metrics and statistics">,
   MarshallingInfoFlag<"FrontendOpts.ShowStats", "false">;
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -143,7 +143,8 @@
 void denormalizeSimpleFlag(SmallVectorImpl<const char *> &Args,
                            const char *Spelling,
                            CompilerInvocation::StringAllocator SA,
-                           unsigned TableIndex, T Value) {
+                           Option::OptionClass OptClass, unsigned TableIndex,
+                           T Value) {
   Args.push_back(Spelling);
 }
 
@@ -177,6 +178,38 @@
     Args.push_back(NegSpelling);
 }
 
+static Optional<std::string> normalizeString(OptSpecifier Opt, int TableIndex,
+                                             const ArgList &Args,
+                                             DiagnosticsEngine &Diags) {
+  auto *Arg = Args.getLastArg(Opt);
+  if (!Arg)
+    return None;
+  return std::string(Arg->getValue());
+}
+
+template <typename T>
+static void denormalizeString(SmallVectorImpl<const char *> &Args,
+                              const char *Spelling,
+                              CompilerInvocation::StringAllocator SA,
+                              Option::OptionClass OptClass, unsigned TableIndex,
+                              T &&Value) {
+  static_assert(std::is_constructible<Twine, T>::value,
+                "Cannot convert this value to Twine");
+  switch (OptClass) {
+  case Option::SeparateClass:
+  case Option::JoinedOrSeparateClass:
+    Args.push_back(Spelling);
+    Args.push_back(SA(Twine(std::forward<T>(Value))));
+    break;
+  case Option::JoinedClass:
+    Args.push_back(SA(Twine(Spelling) + Twine(std::forward<T>(Value))));
+    break;
+  default:
+    llvm_unreachable("Cannot denormalize an option with option class "
+                     "incompatible with string denormalization.");
+  }
+}
+
 static Optional<SimpleEnumValue>
 findValueTableByName(const SimpleEnumValueTable &Table, StringRef Name) {
   for (int I = 0, E = Table.Size; I != E; ++I)
@@ -218,51 +251,19 @@
 static void denormalizeSimpleEnum(SmallVectorImpl<const char *> &Args,
                                   const char *Spelling,
                                   CompilerInvocation::StringAllocator SA,
+                                  Option::OptionClass OptClass,
                                   unsigned TableIndex, unsigned Value) {
   assert(TableIndex < SimpleEnumValueTablesSize);
   const SimpleEnumValueTable &Table = SimpleEnumValueTables[TableIndex];
   if (auto MaybeEnumVal = findValueTableByValue(Table, Value)) {
-    Args.push_back(Spelling);
-    Args.push_back(MaybeEnumVal->Name);
+    denormalizeString(Args, Spelling, SA, OptClass, TableIndex,
+                      MaybeEnumVal->Name);
   } else {
     llvm_unreachable("The simple enum value was not correctly defined in "
                      "the tablegen option description");
   }
 }
 
-static void denormalizeSimpleEnumJoined(SmallVectorImpl<const char *> &Args,
-                                        const char *Spelling,
-                                        CompilerInvocation::StringAllocator SA,
-                                        unsigned TableIndex, unsigned Value) {
-  assert(TableIndex < SimpleEnumValueTablesSize);
-  const SimpleEnumValueTable &Table = SimpleEnumValueTables[TableIndex];
-  if (auto MaybeEnumVal = findValueTableByValue(Table, Value))
-    Args.push_back(SA(Twine(Spelling) + MaybeEnumVal->Name));
-  else
-    llvm_unreachable("The simple enum value was not correctly defined in "
-                     "the tablegen option description");
-}
-
-static Optional<std::string> normalizeString(OptSpecifier Opt, int TableIndex,
-                                             const ArgList &Args,
-                                             DiagnosticsEngine &Diags) {
-  auto *Arg = Args.getLastArg(Opt);
-  if (!Arg)
-    return None;
-  return std::string(Arg->getValue());
-}
-
-template <typename T>
-static void denormalizeString(SmallVectorImpl<const char *> &Args,
-                              const char *Spelling,
-                              CompilerInvocation::StringAllocator SA,
-                              unsigned TableIndex, T &&Value) {
-  static_assert(std::is_constructible<Twine, T>::value,
-                "Cannot convert this value to Twine");
-  Args.push_back(Spelling);
-  Args.push_back(SA(Twine(std::forward<T>(Value))));
-}
-
 template <typename IntTy>
 static Optional<IntTy> normalizeStringIntegral(OptSpecifier Opt, int TableIndex,
                                                const ArgList &Args,
@@ -3474,7 +3475,8 @@
     const auto &Extracted = EXTRACTOR(this->KEYPATH);                          \
     if (ALWAYS_EMIT ||                                                         \
         static_cast<decltype(DEFAULT_VALUE)>(Extracted) != DEFAULT_VALUE)      \
-      DENORMALIZER(Args, SPELLING, SA, TABLE_INDEX, Extracted);                \
+      DENORMALIZER(Args, SPELLING, SA, Option::KIND##Class, TABLE_INDEX,       \
+                   Extracted);                                                 \
   }
 
 #define OPTION_WITH_MARSHALLING_BOOLEAN(                                       \
diff --git a/llvm/include/llvm/Option/OptParser.td b/llvm/include/llvm/Option/OptParser.td
--- a/llvm/include/llvm/Option/OptParser.td
+++ b/llvm/include/llvm/Option/OptParser.td
@@ -198,9 +198,6 @@
   code Normalizer = "normalizeSimpleEnum";
   code Denormalizer = "denormalizeSimpleEnum";
 }
-class AutoNormalizeEnumJoined : AutoNormalizeEnum {
-  code Denormalizer = "denormalizeSimpleEnumJoined";
-}
 class ValueMerger<code merger> { code ValueMerger = merger; }
 class ValueExtractor<code extractor> { code ValueExtractor = extractor; }