Comments

diff --git a/compiler/simplCore/Simplify.lhs b/compiler/simplCore/Simplify.lhs
index c3fb34d..d2e912b 100644 (file)
--- a/compiler/simplCore/Simplify.lhs
+++ b/compiler/simplCore/Simplify.lhs
@@ -735,8 +735,9 @@ simplCast env body co cont
   where
        addCoerce co cont = add_coerce co (coercionKind co) cont
 
-       add_coerce co (s1, k1) cont 
-         | s1 `coreEqType` k1 = cont
+       add_coerce co (s1, k1) cont     -- co :: ty~ty
+         | s1 `coreEqType` k1 = cont   -- is a no-op
+
        add_coerce co1 (s1, k2) (CoerceIt co2 cont)
          | (l1, t1) <- coercionKind co2
                 --     coerce T1 S1 (coerce S1 K1 e)