Tiny optimisation/simplification to FunDeps.grow

diff --git a/compiler/types/FunDeps.lhs b/compiler/types/FunDeps.lhs
index 3d90126..a7e9f19 100644 (file)
--- a/compiler/types/FunDeps.lhs
+++ b/compiler/types/FunDeps.lhs
@@ -153,7 +153,7 @@ See also Note [Ambiguity] in TcSimplify
 \begin{code}
 grow :: [PredType] -> TyVarSet -> TyVarSet
 grow preds fixed_tvs 
-  | null preds = real_fixed_tvs
+  | null preds = fixed_tvs
   | otherwise  = loop real_fixed_tvs
   where
        -- Add the implicit parameters;