import CoreSyn
import Id ( Id, idType, mkSysLocal, getIdDemandInfo, setIdDemandInfo,
- mkWildId )
-import IdInfo ( CprInfo(..), noCprInfo )
+ mkWildId, setIdInfo
+ )
+import IdInfo ( CprInfo(..), noCprInfo, vanillaIdInfo )
import Const ( Con(..), DataCon )
-import DataCon ( dataConArgTys )
+import DataCon ( splitProductType_maybe )
import Demand ( Demand(..) )
import PrelInfo ( realWorldPrimId, aBSENT_ERROR_ID )
import TysPrim ( realWorldStatePrimTy )
import TysWiredIn ( unboxedTupleCon, unboxedTupleTyCon )
import Type ( isUnLiftedType, mkTyVarTys, mkTyVarTy, mkFunTys,
- splitForAllTys, splitFunTysN,
- splitAlgTyConApp_maybe, mkTyConApp,
+ splitForAllTys, splitFunTys, splitFunTysN,
+ splitAlgTyConApp_maybe, splitAlgTyConApp,
+ mkTyConApp, splitNewType_maybe,
Type
)
import TyCon ( isNewTyCon,
CoreExpr -> CoreExpr, -- Worker body, lacking the original function body
[Demand]) -- Strictness info for worker
-mkWwBodies tyvars args body_ty demands cpr_info
- | allAbsent demands &&
- isUnLiftedType body_ty
- = -- Horrid special case. If the worker would have no arguments, and the
- -- function returns a primitive type value, that would make the worker into
- -- an unboxed value. We box it by passing a dummy void argument, thus:
- --
- -- f = /\abc. \xyz. fw abc void
- -- fw = /\abc. \v. body
- --
- -- We use the state-token type which generates no code
- getUniqueUs `thenUs` \ void_arg_uniq ->
- let
- void_arg = mk_ww_local void_arg_uniq realWorldStatePrimTy
- in
- returnUs (\ work_id -> Note InlineMe $ -- Inline the wrapper
- mkLams tyvars $ mkLams args $
- mkApps (Var work_id)
- (map (Type . mkTyVarTy) tyvars ++ [Var realWorldPrimId]),
- \ body -> mkLams (tyvars ++ [void_arg]) body,
- [WwLazy True])
-
mkWwBodies tyvars wrap_args body_ty demands cpr_info
- | otherwise
= let
-- demands may be longer than number of args. If we aren't doing w/w
-- for strictness then demands is an infinite list of 'lazy' args.
wrap_args_w_demands = zipWith setIdDemandInfo wrap_args demands
+ (wrap_fn_coerce, work_fn_coerce) = mkWWcoerce body_ty
in
- mkWW wrap_args_w_demands `thenUs` \ (wrap_fn, work_args_w_demands, work_fn) ->
+ mkWWstr body_ty wrap_args_w_demands `thenUs` \ (work_args_w_demands, wrap_fn_str, work_fn_str) ->
- mkWWcpr body_ty cpr_info `thenUs` \ (wrap_fn_w_cpr, work_fn_w_cpr) ->
+ mkWWcpr body_ty cpr_info `thenUs` \ (wrap_fn_cpr, work_fn_cpr) ->
returnUs (\ work_id -> Note InlineMe $
mkLams tyvars $ mkLams wrap_args_w_demands $
- (wrap_fn_w_cpr . wrap_fn) (mkTyApps (Var work_id) (mkTyVarTys tyvars)),
+ (wrap_fn_coerce . wrap_fn_str . wrap_fn_cpr) $
+ mkVarApps (Var work_id) (tyvars ++ work_args_w_demands),
- \ body -> mkLams tyvars $ mkLams work_args_w_demands $
- (work_fn_w_cpr . work_fn) body,
+ \ work_body -> mkLams tyvars $ mkLams work_args_w_demands $
+ (work_fn_coerce . work_fn_str . work_fn_cpr)
+ work_body,
map getIdDemandInfo work_args_w_demands)
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Coercion stuff}
+%* *
+%************************************************************************
+
+The "coerce" transformation is
+ f :: T1 -> T2 -> R
+ f = \xy -> e
+===>
+ f = \xy -> coerce R R' (fw x y)
+ fw = \xy -> coerce R' R e
+
+where R' is the representation type for R.
+
+\begin{code}
+mkWWcoerce body_ty
+ = case splitNewType_maybe body_ty of
+ Nothing -> (id, id)
+ Just rep_ty -> (mkNote (Coerce body_ty rep_ty),
+ mkNote (Coerce rep_ty body_ty))
\end{code}
+
+%************************************************************************
+%* *
+\subsection{Strictness stuff}
+%* *
+%************************************************************************
+
+
\begin{code}
-mkWW :: [Id] -- Wrapper args; have their demand info on them
- -> UniqSM (CoreExpr -> CoreExpr, -- Wrapper body, lacking the inner call to the worker
- -- and without its lambdas
- [Id], -- Worker args; have their demand info on them
- CoreExpr -> CoreExpr) -- Worker body, lacking the original body of the function
+mkWWstr :: Type -- Body type
+ -> [Id] -- Wrapper args; have their demand info on them
+ -> UniqSM ([Id], -- Worker args; have their demand info on them
+
+ CoreExpr -> CoreExpr, -- Wrapper body, lacking the inner call to the worker
+ -- and without its lambdas
+ -- At the call site, the worker args are bound
+
+ CoreExpr -> CoreExpr) -- Worker body, lacking the original body of the function,
+ -- and without its lambdas
+
+mkWWstr body_ty wrap_args
+ = mk_ww wrap_args `thenUs` \ (work_args, wrap_fn, work_fn) ->
+
+ if null work_args && isUnLiftedType body_ty then
+ -- Horrid special case. If the worker would have no arguments, and the
+ -- function returns a primitive type value, that would make the worker into
+ -- an unboxed value. We box it by passing a dummy void argument, thus:
+ --
+ -- f = /\abc. \xyz. fw abc void
+ -- fw = /\abc. \v. body
+ --
+ -- We use the state-token type which generates no code
+ getUniqueUs `thenUs` \ void_arg_uniq ->
+ let
+ void_arg = mk_ww_local void_arg_uniq realWorldStatePrimTy
+ in
+ returnUs ([void_arg],
+ wrap_fn . Let (NonRec void_arg (Var realWorldPrimId)),
+ work_fn)
+ else
+ returnUs (work_args, wrap_fn, work_fn)
+
-- Empty case
-mkWW []
- = returnUs (\ wrapper_body -> wrapper_body,
- [],
+mk_ww []
+ = returnUs ([],
+ \ wrapper_body -> wrapper_body,
\ worker_body -> worker_body)
-mkWW (arg : ds)
+mk_ww (arg : ds)
= case getIdDemandInfo arg of
-- Absent case
WwLazy True ->
- mkWW ds `thenUs` \ (wrap_fn, worker_args, work_fn) ->
- returnUs (\ wrapper_body -> wrap_fn wrapper_body,
- worker_args,
- \ worker_body -> mk_absent_let arg (work_fn worker_body))
-
+ mk_ww ds `thenUs` \ (worker_args, wrap_fn, work_fn) ->
+ returnUs (worker_args, wrap_fn, mk_absent_let arg . work_fn)
-- Unpack case
WwUnpack new_or_data True cs ->
getUniquesUs (length inst_con_arg_tys) `thenUs` \ uniqs ->
let
unpk_args = zipWith mk_ww_local uniqs inst_con_arg_tys
- unpk_args_w_ds = zipWithEqual "mkWW" setIdDemandInfo unpk_args cs
+ unpk_args_w_ds = zipWithEqual "mk_ww" setIdDemandInfo unpk_args cs
in
- mkWW (unpk_args_w_ds ++ ds) `thenUs` \ (wrap_fn, worker_args, work_fn) ->
- returnUs (\ wrapper_body -> mk_unpk_case new_or_data arg unpk_args data_con arg_tycon
- (wrap_fn wrapper_body),
- worker_args,
- \ worker_body -> work_fn (mk_pk_let new_or_data arg data_con
- tycon_arg_tys unpk_args worker_body))
+ mk_ww (unpk_args_w_ds ++ ds) `thenUs` \ (worker_args, wrap_fn, work_fn) ->
+ returnUs (worker_args,
+ mk_unpk_case new_or_data arg unpk_args data_con arg_tycon . wrap_fn,
+ work_fn . mk_pk_let new_or_data arg data_con tycon_arg_tys unpk_args)
where
- inst_con_arg_tys = dataConArgTys data_con tycon_arg_tys
- (arg_tycon, tycon_arg_tys, data_con)
- = case (splitAlgTyConApp_maybe (idType arg)) of
-
- Just (arg_tycon, tycon_arg_tys, [data_con]) ->
- -- The main event: a single-constructor data type
- (arg_tycon, tycon_arg_tys, data_con)
-
- Just (_, _, data_cons) ->
- pprPanic "mk_ww_arg_processing:"
- (text "not one constr (interface files not consistent/up to date?)"
- $$ (ppr arg <+> ppr (idType arg)))
-
- Nothing ->
- panic "mk_ww_arg_processing: not datatype"
-
+ (arg_tycon, tycon_arg_tys, data_con, inst_con_arg_tys) = splitProductType "mk_ww" (idType arg)
-- Other cases
other_demand ->
- mkWW ds `thenUs` \ (wrap_fn, worker_args, work_fn) ->
- returnUs (\ wrapper_body -> wrap_fn (App wrapper_body (Var arg)),
- arg : worker_args,
- work_fn)
+ mk_ww ds `thenUs` \ (worker_args, wrap_fn, work_fn) ->
+ returnUs (arg : worker_args, wrap_fn, work_fn)
\end{code}
+
+%************************************************************************
+%* *
+\subsection{CPR stuff}
+%* *
+%************************************************************************
+
+
@mkWWcpr@ takes the worker/wrapper pair produced from the strictness
info and adds in the CPR transformation. The worker returns an
unboxed tuple containing non-CPR components. The wrapper takes this
| isNewTyCon tycon -- a new type: under the coercions must be a
-- constructed product
= ASSERT ( null $ tail inst_con_arg_tys )
- mk_cpr_case (head inst_con_arg_tys, cpr_info)
+ mk_cpr_case (target_of_from_type, cpr_info)
`thenUs` \(arg, tup, exp) ->
getUniqueUs `thenUs` \id_uniq ->
let id_id = mk_ww_local id_uniq ty
in
returnUs (id_id, new_tup, new_exp_case)
where
- (data_con, tycon, tycon_arg_tys, inst_con_arg_tys) = splitType "mk_cpr_case" ty
+ (tycon, tycon_arg_tys, data_con, inst_con_arg_tys) = splitProductType "mk_cpr_case" ty
+ from_type = head inst_con_arg_tys
+ -- if coerced from a function 'look through' to find result type
+ target_of_from_type = (snd.splitFunTys.snd.splitForAllTys) from_type
\end{code}
mk_cpr_let (ty, cpr_info@(CPRInfo ci_args))
| isNewTyCon tycon -- a new type: must coerce the argument to this type
= ASSERT ( null $ tail inst_con_arg_tys )
- mk_cpr_let (head inst_con_arg_tys, cpr_info)
+ mk_cpr_let (target_of_from_type, cpr_info)
`thenUs` \(arg, tup, exp) ->
getUniqueUs `thenUs` \id_uniq ->
let id_id = mk_ww_local id_uniq ty
in
returnUs (id_id, new_tup, new_exp)
where
- (data_con, tycon, tycon_arg_tys, inst_con_arg_tys) = splitType "mk_cpr_let" ty
+ (tycon, tycon_arg_tys, data_con, inst_con_arg_tys) = splitProductType "mk_cpr_let" ty
+ from_type = head inst_con_arg_tys
+ -- if coerced from a function 'look through' to find result type
+ target_of_from_type = (snd.splitFunTys.snd.splitForAllTys) from_type
-splitType :: String -> Type -> (DataCon, TyCon, [Type], [Type])
-splitType fname ty = (data_con, tycon, tycon_arg_tys, dataConArgTys data_con tycon_arg_tys)
- where
- (data_con, tycon, tycon_arg_tys)
- = case (splitAlgTyConApp_maybe ty) of
- Just (arg_tycon, tycon_arg_tys, [data_con]) ->
- -- The main event: a single-constructor data type
- (data_con, arg_tycon, tycon_arg_tys)
-
- Just (_, _, data_cons) ->
- pprPanic (fname ++ ":")
- (text "not one constr (interface files not consistent/up to date?)"
- $$ ppr ty)
-
- Nothing ->
- pprPanic (fname ++ ":")
- (text "not a datatype" $$ ppr ty)
+
+splitProductType :: String -> Type -> (TyCon, [Type], DataCon, [Type])
+splitProductType fname ty = case splitProductType_maybe ty of
+ Just stuff -> stuff
+ Nothing -> pprPanic (fname ++ ": not a product") (ppr ty)
\end{code}
-- A newtype! Use a coercion not a case
= ASSERT( null other_args )
Case (Note (Coerce (idType unpk_arg) (idType arg)) (Var arg))
- unpk_arg
+ (sanitiseCaseBndr unpk_arg)
[(DEFAULT,[],body)]
where
(unpk_arg:other_args) = unpk_args
mk_unpk_case DataType arg unpk_args boxing_con boxing_tycon body
-- A data type
- = Case (Var arg) arg [(DataCon boxing_con, unpk_args, body)]
+ = Case (Var arg)
+ (sanitiseCaseBndr arg)
+ [(DataCon boxing_con, unpk_args, body)]
+
+sanitiseCaseBndr :: Id -> Id
+-- The argument we are scrutinising has the right type to be
+-- a case binder, so it's convenient to re-use it for that purpose.
+-- But we *must* throw away all its IdInfo. In particular, the argument
+-- will have demand info on it, and that demand info may be incorrect for
+-- the case binder. e.g. case ww_arg of ww_arg { I# x -> ... }
+-- Quite likely ww_arg isn't used in '...'. The case may get discarded
+-- if the case binder says "I'm demanded". This happened in a situation
+-- like (x+y) `seq` ....
+sanitiseCaseBndr id = id `setIdInfo` vanillaIdInfo
mk_pk_let NewType arg boxing_con con_tys unpk_args body
= ASSERT( null other_args )
map fst contents),
mkTyConApp (unboxedTupleTyCon (length contents))
(map snd contents))
-
-
\end{code}
projects / ghc-hetmet.git / blobdiff