diff --git a/include/llvm/TableGen/Record.h b/include/llvm/TableGen/Record.h
index afce7609986..0fc50c5a3bc 100644
--- a/include/llvm/TableGen/Record.h
+++ b/include/llvm/TableGen/Record.h
@@ -1568,6 +1568,23 @@ struct MultiClass {
   typedef std::vector<Record*> RecordVector;
   RecordVector DefPrototypes;
 
+  struct MultiDef {
+    Record *Rec;          // The base record for all defs generated.
+                          // This serves as the multiclass def prototype.
+    TypedInit *List;      // A list of values to process.
+                          // Each one generates a new def.
+    IntInit *Start;       // This specified the list index from which to start
+                          // processing.
+    std::string ItemName; // The name of a temporary iterator value to
+                          // track the current list item being processed.
+
+    MultiDef(Record *R, TypedInit *L, IntInit *S, const std::string &I) 
+        : Rec(R), List(L), Start(S), ItemName(I) {};
+  };
+
+  typedef std::vector<MultiDef> MultiDefVector;
+  MultiDefVector MultiDefPrototypes;
+
   void dump() const;
 
   MultiClass(const std::string &Name, SMLoc Loc, RecordKeeper &Records) :