diff --git a/llvm/utils/TableGen/CodeGenMapTable.cpp b/llvm/utils/TableGen/CodeGenMapTable.cpp
index 57d86a8fc1191..ea53a2d3eee6c 100644
--- a/llvm/utils/TableGen/CodeGenMapTable.cpp
+++ b/llvm/utils/TableGen/CodeGenMapTable.cpp
@@ -144,9 +144,9 @@ class InstrMap {
     }
   }
 
-  std::string getName() const { return Name; }
+  const std::string &getName() const { return Name; }
 
-  std::string getFilterClass() const { return FilterClass; }
+  const std::string &getFilterClass() const { return FilterClass; }
 
   ListInit *getRowFields() const { return RowFields; }
 
@@ -190,7 +190,7 @@ class MapTableEmitter {
 public:
   MapTableEmitter(CodeGenTarget &Target, RecordKeeper &Records, Record *IMRec):
                   Target(Target), InstrMapDesc(IMRec) {
-    const std::string FilterClass = InstrMapDesc.getFilterClass();
+    const std::string &FilterClass = InstrMapDesc.getFilterClass();
     InstrDefs = Records.getAllDerivedDefinitions(FilterClass);
   }