-newFamInstTyConName :: Name -> SrcSpan -> TcM Name
-newFamInstTyConName tc_name loc
- = do { index <- nextDFunIndex
- ; mod <- getModule
- ; let occ = nameOccName tc_name
- ; newGlobalBinder mod (mkInstTyTcOcc index occ) loc }
+newFamInstTyConName :: Name -> [Type] -> SrcSpan -> TcM Name
+newFamInstTyConName tc_name tys loc
+ = do { mod <- getModule
+ ; let info_string = occNameString (getOccName tc_name) ++
+ concatMap (occNameString.getDFunTyKey) tys
+ ; occ <- chooseUniqueOccTc (mkInstTyTcOcc info_string)
+ ; newGlobalBinder mod occ loc }