Add a coercion optimiser, to reduce the size of coercion terms

[ghc-hetmet.git] / compiler / simplCore / Simplify.lhs

diff --git a/compiler/simplCore/Simplify.lhs b/compiler/simplCore/Simplify.lhs
index 69ac95b..18b3fc6 100644 (file)
--- a/compiler/simplCore/Simplify.lhs
+++ b/compiler/simplCore/Simplify.lhs
@@ -822,6 +822,12 @@ simplType env ty
     seqType new_ty   `seq`   return new_ty
   where
     new_ty = substTy env ty
+
+---------------------------------
+simplCoercion :: SimplEnv -> InType -> SimplM OutType
+simplCoercion env co
+  = do { co' <- simplType env co
+       ; return (optCoercion co') }
 \end{code}
 
 
@@ -859,7 +865,7 @@ rebuild env expr cont0
 simplCast :: SimplEnv -> InExpr -> Coercion -> SimplCont
           -> SimplM (SimplEnv, OutExpr)
 simplCast env body co0 cont0
-  = do  { co1 <- simplType env co0
+  = do  { co1 <- simplCoercion env co0
         ; simplExprF env body (addCoerce co1 cont0) }
   where
        addCoerce co cont = add_coerce co (coercionKind co) cont