Massive patch for the first months work adding System FC to GHC #33

Broken up massive patch -=chak
Original log message:
This is (sadly) all done in one patch to avoid Darcs bugs.
It's not complete work... more FC stuff to come.  A compiler
using just this patch will fail dismally.

diff --git a/compiler/stranal/DmdAnal.lhs b/compiler/stranal/DmdAnal.lhs
index 127fa78..3fc8477 100644 (file)
--- a/compiler/stranal/DmdAnal.lhs
+++ b/compiler/stranal/DmdAnal.lhs
@@ -40,7 +40,8 @@ import TysWiredIn     ( unboxedPairDataCon )
 import TysPrim         ( realWorldStatePrimTy )
 import UniqFM          ( plusUFM_C, addToUFM_Directly, lookupUFM_Directly,
                          keysUFM, minusUFM, ufmToList, filterUFM )
-import Type            ( isUnLiftedType, coreEqType )
+import Type            ( isUnLiftedType, coreEqType, splitTyConApp_maybe )
+import Coercion         ( coercionKind )
 import CoreLint                ( showPass, endPass )
 import Util            ( mapAndUnzip, mapAccumL, mapAccumR, lengthIs )
 import BasicTypes      ( Arity, TopLevelFlag(..), isTopLevel, isNeverActive,
@@ -164,16 +165,25 @@ dmdAnal sigs dmd (Lit lit)
 dmdAnal sigs dmd (Var var)
   = (dmdTransform sigs var dmd, Var var)
 
+dmdAnal sigs dmd (Cast e co)
+  = (dmd_ty, Cast e' co)
+  where
+    (dmd_ty, e') = dmdAnal sigs dmd' e
+    to_co        = snd (coercionKind co)
+    dmd'
+      | Just (tc, args) <- splitTyConApp_maybe to_co
+      , isRecursiveTyCon tc = evalDmd
+      | otherwise           = dmd
+       -- This coerce usually arises from a recursive
+        -- newtype, and we don't want to look inside them
+       -- for exactly the same reason that we don't look
+       -- inside recursive products -- we might not reach
+       -- a fixpoint.  So revert to a vanilla Eval demand
+
 dmdAnal sigs dmd (Note n e)
   = (dmd_ty, Note n e')
   where
-    (dmd_ty, e') = dmdAnal sigs dmd' e 
-    dmd' = case n of
-            Coerce _ _ -> evalDmd  -- This coerce usually arises from a recursive
-            other      -> dmd      -- newtype, and we don't want to look inside them
-                                   -- for exactly the same reason that we don't look
-                                   -- inside recursive products -- we might not reach
-                                   -- a fixpoint.  So revert to a vanilla Eval demand
+    (dmd_ty, e') = dmdAnal sigs dmd e  
 
 dmdAnal sigs dmd (App fun (Type ty))
   = (fun_ty, App fun' (Type ty))

diff --git a/compiler/stranal/WorkWrap.lhs b/compiler/stranal/WorkWrap.lhs
index 29702cf..2f5d38c 100644 (file)
--- a/compiler/stranal/WorkWrap.lhs
+++ b/compiler/stranal/WorkWrap.lhs
@@ -153,6 +153,10 @@ wwExpr (Note note expr)
   = wwExpr expr                        `thenUs` \ new_expr ->
     returnUs (Note note new_expr)
 
+wwExpr (Cast expr co)
+  = wwExpr expr                        `thenUs` \ new_expr ->
+    returnUs (Cast new_expr co)
+
 wwExpr (Let bind expr)
   = wwBind bind                        `thenUs` \ intermediate_bind ->
     wwExpr expr                        `thenUs` \ new_expr ->

diff --git a/compiler/stranal/WwLib.lhs b/compiler/stranal/WwLib.lhs
index e44e521..f3af6f0 100644 (file)
--- a/compiler/stranal/WwLib.lhs
+++ b/compiler/stranal/WwLib.lhs
@@ -22,6 +22,7 @@ import TysWiredIn     ( tupleCon )
 import Type            ( Type, isUnLiftedType, mkFunTys,
                          splitForAllTys, splitFunTys, splitRecNewType_maybe, isAlgType
                        )
+import Coercion         ( Coercion, mkSymCoercion, splitRecNewTypeCo_maybe )
 import BasicTypes      ( Boxity(..) )
 import Var              ( Var, isId )
 import UniqSupply      ( returnUs, thenUs, getUniquesUs, UniqSM )
@@ -223,7 +224,7 @@ mkWWargs :: Type
                     Type)                      -- Type of wrapper body
 
 mkWWargs fun_ty demands one_shots
-  | Just rep_ty <- splitRecNewType_maybe fun_ty
+  | Just (rep_ty, co) <- splitRecNewTypeCo_maybe fun_ty
        -- The newtype case is for when the function has
        -- a recursive newtype after the arrow (rare)
        -- We check for arity >= 0 to avoid looping in the case
@@ -236,8 +237,8 @@ mkWWargs fun_ty demands one_shots
        -- simply coerces.
   = mkWWargs rep_ty demands one_shots  `thenUs` \ (wrap_args, wrap_fn_args, work_fn_args, res_ty) ->
     returnUs (wrap_args,
-             Note (Coerce fun_ty rep_ty) . wrap_fn_args,
-             work_fn_args . Note (Coerce rep_ty fun_ty),
+             \ e -> Cast (wrap_fn_args e) co,
+             \ e -> work_fn_args (Cast e (mkSymCoercion co)),
              res_ty)
 
   | notNull demands