diff --git a/llvm/lib/TableGen/TGParser.cpp b/llvm/lib/TableGen/TGParser.cpp
index 4b7ccdc..13feae0 100644
--- a/llvm/lib/TableGen/TGParser.cpp
+++ b/llvm/lib/TableGen/TGParser.cpp
@@ -459,7 +459,7 @@
     return nullptr;
   }
 
-  MultiClass *Result = MultiClasses[Lex.getCurStrVal()];
+  MultiClass *Result = MultiClasses[Lex.getCurStrVal()].get();
   if (!Result)
     TokError("Couldn't find multiclass '" + Lex.getCurStrVal() + "'");
 
@@ -2290,11 +2290,14 @@
     return TokError("expected identifier after multiclass for name");
   std::string Name = Lex.getCurStrVal();
 
-  if (MultiClasses.count(Name))
+  auto Result =
+    MultiClasses.insert(std::make_pair(Name,
+                    llvm::make_unique<MultiClass>(Name, Lex.getLoc(),Records)));
+
+  if (!Result.second)
     return TokError("multiclass '" + Name + "' already defined");
 
-  CurMultiClass = MultiClasses[Name] = new MultiClass(Name, 
-                                                      Lex.getLoc(), Records);
+  CurMultiClass = Result.first->second.get();
   Lex.Lex();  // Eat the identifier.
 
   // If there are template args, parse them.
@@ -2555,7 +2558,7 @@
     // To instantiate a multiclass, we need to first get the multiclass, then
     // instantiate each def contained in the multiclass with the SubClassRef
     // template parameters.
-    MultiClass *MC = MultiClasses[Ref.Rec->getName()];
+    MultiClass *MC = MultiClasses[Ref.Rec->getName()].get();
     assert(MC && "Didn't lookup multiclass correctly?");
     std::vector<Init*> &TemplateVals = Ref.TemplateArgs;