Index: utils/TableGen/CodeGenRegisters.h
===================================================================
--- utils/TableGen/CodeGenRegisters.h
+++ utils/TableGen/CodeGenRegisters.h
@@ -74,8 +74,7 @@
     std::string getQualifiedName() const;
 
     // Map of composite subreg indices.
-    typedef std::map<CodeGenSubRegIndex *, CodeGenSubRegIndex *,
-                     deref<llvm::less>> CompMap;
+    typedef DenseMap<CodeGenSubRegIndex *, CodeGenSubRegIndex *> CompMap;
 
     // Returns the subreg index that results from composing this with Idx.
     // Returns NULL if this and Idx don't compose.