\begin{code}
module WwLib (
- WwBinding(..),
-
- worthSplitting, setUnpackStrategy,
- mkWwBodies, mkWrapper
+ mkWwBodies,
+ worthSplitting, setUnpackStrategy
) where
#include "HsVersions.h"
import CoreSyn
-import Id ( Id, idType, mkSysLocal, getIdDemandInfo, setIdDemandInfo,
+import CoreUtils ( exprType, mkInlineMe )
+import Id ( Id, idType, mkSysLocal, idDemandInfo, setIdDemandInfo,
+ isOneShotLambda, setOneShotLambda,
mkWildId, setIdInfo
)
import IdInfo ( CprInfo(..), noCprInfo, vanillaIdInfo )
-import Const ( Con(..), DataCon )
-import DataCon ( splitProductType_maybe, isExistentialDataCon, dataConArgTys )
-import Demand ( Demand(..) )
+import DataCon ( DataCon, splitProductType )
+import Demand ( Demand(..), wwLazy, wwPrim )
import PrelInfo ( realWorldPrimId, aBSENT_ERROR_ID )
import TysPrim ( realWorldStatePrimTy )
-import TysWiredIn ( unboxedTupleCon, unboxedTupleTyCon )
-import Type ( isUnLiftedType, mkTyVarTys, mkTyVarTy, mkFunTys,
- splitForAllTys, splitFunTys, splitFunTysN,
- splitAlgTyConApp_maybe, splitAlgTyConApp,
- mkTyConApp, splitNewType_maybe,
+import TysWiredIn ( tupleCon )
+import Type ( isUnLiftedType,
+ splitForAllTys, splitFunTys, isAlgType,
+ splitNewType_maybe,
+ mkTyConApp, mkFunTys,
Type
)
-import TyCon ( isNewTyCon, isProductTyCon, TyCon )
-import BasicTypes ( NewOrData(..) )
-import Var ( TyVar )
+import BasicTypes ( NewOrData(..), Arity, Boxity(..) )
+import Var ( TyVar, Var, isId )
import UniqSupply ( returnUs, thenUs, getUniqueUs, getUniquesUs,
mapUs, UniqSM )
-import Util ( zipWithEqual, zipEqual )
+import Util ( zipWithEqual, zipEqual, lengthExceeds )
import Outputable
+import List ( zipWith4 )
\end{code}
-%************************************************************************
-%* *
-\subsection[datatype-WwLib]{@WwBinding@: a datatype for worker/wrapper-ing}
-%* *
-%************************************************************************
-
-In the worker/wrapper stuff, we want to carry around @CoreBindings@ in
-an ``intermediate form'' that can later be turned into a \tr{let} or
-\tr{case} (depending on strictness info).
-
-\begin{code}
-data WwBinding
- = WwLet [CoreBind]
- | WwCase (CoreExpr -> CoreExpr)
- -- the "case" will be a "strict let" of the form:
- --
- -- case rhs of
- -- <blah> -> body
- --
- -- (instead of "let <blah> = rhs in body")
- --
- -- The expr you pass to the function is "body" (the
- -- expression that goes "in the corner").
-\end{code}
%************************************************************************
%* *
worthSplitting :: [Demand]
-> Bool -- Result is bottom
-> Bool -- True <=> the wrapper would not be an identity function
-worthSplitting ds result_bot = not result_bot && any worth_it ds
- -- Don't split if the result is bottom; there's no efficiency to
- -- be gained, and (worse) the wrapper body may not look like a wrapper
- -- body to getWorkerIdAndCons
+worthSplitting ds result_bot = any worth_it ds
+ -- We used not to split if the result is bottom.
+ -- [Justification: there's no efficiency to be gained.]
+ -- But it's sometimes bad not to make a wrapper. Consider
+ -- fw = \x# -> let x = I# x# in case e of
+ -- p1 -> error_fn x
+ -- p2 -> error_fn x
+ -- p3 -> the real stuff
+ -- The re-boxing code won't go away unless error_fn gets a wrapper too.
+
where
worth_it (WwLazy True) = True -- Absent arg
worth_it (WwUnpack _ True _) = True -- Arg to unpack
%* *
%************************************************************************
-@mkWrapper@ is called when importing a function. We have the type of
-the function and the name of its worker, and we want to make its body (the wrapper).
-
-\begin{code}
-mkWrapper :: Type -- Wrapper type
- -> Int -- Arity
- -> [Demand] -- Wrapper strictness info
- -> CprInfo -- Wrapper cpr info
- -> UniqSM (Id -> CoreExpr) -- Wrapper body, missing worker Id
-
-mkWrapper fun_ty arity demands cpr_info
- = getUniquesUs arity `thenUs` \ wrap_uniqs ->
- let
- (tyvars, tau_ty) = splitForAllTys fun_ty
- (arg_tys, body_ty) = splitFunTysN "mkWrapper" arity tau_ty
- -- The "expanding dicts" part here is important, even for the splitForAll
- -- The imported thing might be a dictionary, such as Functor Foo
- -- But Functor Foo = forall a b. (a->b) -> Foo a -> Foo b
- -- and as such might have some strictness info attached.
- -- Then we need to have enough args to zip to the strictness info
-
- wrap_args = zipWith mk_ww_local wrap_uniqs arg_tys
- in
- mkWwBodies tyvars wrap_args body_ty demands cpr_info `thenUs` \ (wrap_fn, _, _) ->
- returnUs wrap_fn
-\end{code}
-
@mkWwBodies@ is called when doing the worker/wrapper split inside a module.
\begin{code}
-mkWwBodies :: [TyVar] -> [Id] -- Original fn args
- -> Type -- Type of result of original function
- -> [Demand] -- Strictness info for original fn; corresp 1-1 with args
+mkWwBodies :: Type -- Type of original function
+ -> Arity -- Arity of original function
+ -> [Demand] -- Strictness of original function
+ -> Bool -- True <=> function returns bottom
+ -> [Bool] -- One-shot-ness of the function
-> CprInfo -- Result of CPR analysis
- -> UniqSM (Id -> CoreExpr, -- Wrapper body, lacking only the worker Id
- CoreExpr -> CoreExpr, -- Worker body, lacking the original function body
- [Demand]) -- Strictness info for worker
-
-mkWwBodies tyvars wrap_args res_ty demands cpr_info
- = 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
-
- in
- mkWWstr wrap_args_w_demands `thenUs` \ (wrap_fn_str, work_fn_str, work_arg_dmds) ->
- mkWWcoerce res_ty `thenUs` \ (wrap_fn_coerce, work_fn_coerce, coerce_res_ty) ->
- mkWWcpr coerce_res_ty cpr_info `thenUs` \ (wrap_fn_cpr, work_fn_cpr, cpr_res_ty) ->
- mkWWfixup cpr_res_ty (null work_arg_dmds) `thenUs` \ (wrap_fn_fixup, work_fn_fixup) ->
-
- returnUs (\ work_id -> Note InlineMe $
- mkLams tyvars $ mkLams wrap_args_w_demands $
- (wrap_fn_coerce . wrap_fn_cpr . wrap_fn_str . wrap_fn_fixup) $
- mkVarApps (Var work_id) tyvars,
-
- \ work_body -> mkLams tyvars $
- (work_fn_fixup . work_fn_str . work_fn_cpr . work_fn_coerce)
- work_body,
-
- work_arg_dmds)
+ -> UniqSM ([Demand], -- Demands for worker (value) args
+ Id -> CoreExpr, -- Wrapper body, lacking only the worker Id
+ CoreExpr -> CoreExpr) -- Worker body, lacking the original function rhs
+
+mkWwBodies fun_ty arity demands res_bot one_shots cpr_info
+ = mkWWargs fun_ty arity demands' res_bot one_shots' `thenUs` \ (wrap_args, wrap_fn_args, work_fn_args, res_ty) ->
+ mkWWstr wrap_args `thenUs` \ (work_dmds, wrap_fn_str, work_fn_str) ->
+ mkWWcpr res_ty cpr_info `thenUs` \ (wrap_fn_cpr, work_fn_cpr, cpr_res_ty) ->
+ mkWWfixup cpr_res_ty work_dmds `thenUs` \ (final_work_dmds, wrap_fn_fixup, work_fn_fixup) ->
+
+ returnUs (final_work_dmds,
+ Note InlineMe . wrap_fn_args . wrap_fn_cpr . wrap_fn_str . wrap_fn_fixup . Var,
+ work_fn_fixup . work_fn_str . work_fn_cpr . work_fn_args)
+ -- We use an INLINE unconditionally, even if the wrapper turns out to be
+ -- something trivial like
+ -- fw = ...
+ -- f = __inline__ (coerce T fw)
+ -- The point is to propagate the coerce to f's call sites, so even though
+ -- f's RHS is now trivial (size 1) we still want the __inline__ to prevent
+ -- fw from being inlined into f's RHS
+ where
+ demands' = demands ++ repeat wwLazy
+ one_shots' = one_shots ++ repeat False
\end{code}
%* *
%************************************************************************
-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.
+We really want to "look through" coerces.
+Reason: I've seen this situation:
-\begin{code}
-mkWWcoerce body_ty
- = case splitNewType_maybe body_ty of
+ let f = coerce T (\s -> E)
+ in \x -> case x of
+ p -> coerce T' f
+ q -> \s -> E2
+ r -> coerce T' f
- Nothing -> returnUs (id, id, body_ty)
+If only we w/w'd f, we'd get
+ let f = coerce T (\s -> fw s)
+ fw = \s -> E
+ in ...
- Just rep_ty -> returnUs (mkNote (Coerce body_ty rep_ty),
- mkNote (Coerce rep_ty body_ty),
- rep_ty)
-\end{code}
+Now we'll inline f to get
+ let fw = \s -> E
+ in \x -> case x of
+ p -> fw
+ q -> \s -> E2
+ r -> fw
+
+Now we'll see that fw has arity 1, and will arity expand
+the \x to get what we want.
+
+\begin{code}
+-- mkWWargs is driven off the function type and arity.
+-- It chomps bites off foralls, arrows, newtypes
+-- and keeps repeating that until it's satisfied the supplied arity
+
+mkWWargs :: Type -> Arity
+ -> [Demand] -> Bool -> [Bool] -- Both these will in due course be derived
+ -- from the type. The [Bool] is True for a one-shot arg.
+ -- ** Both are infinite, extended with neutral values if necy **
+ -> UniqSM ([Var], -- Wrapper args
+ CoreExpr -> CoreExpr, -- Wrapper fn
+ CoreExpr -> CoreExpr, -- Worker fn
+ Type) -- Type of wrapper body
+
+mkWWargs fun_ty arity demands res_bot one_shots
+ | (res_bot || arity > 0) && (not (null tyvars) || n_arg_tys > 0)
+ -- If the function returns bottom, we feel free to
+ -- build lots of wrapper args:
+ -- \x. let v=E in \y. bottom
+ -- = \xy. let v=E in bottom
+ = getUniquesUs n_args `thenUs` \ wrap_uniqs ->
+ let
+ val_args = zipWith4 mk_wrap_arg wrap_uniqs arg_tys demands one_shots
+ wrap_args = tyvars ++ val_args
+ in
+ mkWWargs new_fun_ty
+ (arity - n_args)
+ (drop n_args demands)
+ res_bot
+ (drop n_args one_shots) `thenUs` \ (more_wrap_args, wrap_fn_args, work_fn_args, res_ty) ->
+
+ returnUs (wrap_args ++ more_wrap_args,
+ mkLams wrap_args . wrap_fn_args,
+ work_fn_args . applyToVars wrap_args,
+ res_ty)
+ where
+ (tyvars, tau) = splitForAllTys fun_ty
+ (arg_tys, body_ty) = splitFunTys tau
+ n_arg_tys = length arg_tys
+ n_args | res_bot = n_arg_tys
+ | otherwise = arity `min` n_arg_tys
+ new_fun_ty | n_args == n_arg_tys = body_ty
+ | otherwise = mkFunTys (drop n_args arg_tys) body_ty
+
+mkWWargs fun_ty arity demands res_bot one_shots
+ = case splitNewType_maybe fun_ty of
+ Nothing -> returnUs ([], id, id, fun_ty)
+ Just rep_ty -> mkWWargs rep_ty arity demands res_bot 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),
+ res_ty)
+
+
+applyToVars :: [Var] -> CoreExpr -> CoreExpr
+applyToVars vars fn = mkVarApps fn vars
+
+mk_wrap_arg uniq ty dmd one_shot
+ = set_one_shot one_shot (setIdDemandInfo (mkSysLocal SLIT("w") uniq ty) dmd)
+ where
+ set_one_shot True id = setOneShotLambda id
+ set_one_shot False id = id
+\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-mkWWfixup res_ty no_worker_args
- | no_worker_args && isUnLiftedType res_ty
+mkWWfixup res_ty work_dmds
+ | null work_dmds && isUnLiftedType res_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:
let
void_arg = mk_ww_local void_arg_uniq realWorldStatePrimTy
in
- returnUs (\ call_to_worker -> App call_to_worker (Var void_arg),
+ returnUs ([wwPrim],
+ \ call_to_worker -> App call_to_worker (Var realWorldPrimId),
\ worker_body -> Lam void_arg worker_body)
| otherwise
- = returnUs (id, id)
+ = returnUs (work_dmds, id, id)
\end{code}
%************************************************************************
\begin{code}
-mkWWstr :: [Id] -- Wrapper args; have their demand info on them
- -> UniqSM (CoreExpr -> CoreExpr, -- Wrapper body, lacking the worker call
+mkWWstr :: [Var] -- Wrapper args; have their demand info on them
+ -- *Includes type variables*
+ -> UniqSM ([Demand], -- Demand on worker (value) args
+ CoreExpr -> CoreExpr, -- Wrapper body, lacking the worker call
-- and without its lambdas
-- This fn adds the unboxing, and makes the
-- call passing the unboxed things
- CoreExpr -> CoreExpr, -- Worker body, lacking the original body of the function,
+ CoreExpr -> CoreExpr) -- Worker body, lacking the original body of the function,
-- but *with* lambdas
- [Demand]) -- Worker arg demands
mkWWstr wrap_args
- = mk_ww_str wrap_args `thenUs` \ (work_args_w_demands, wrap_fn, work_fn) ->
- returnUs ( \ wrapper_body -> wrap_fn (mkVarApps wrapper_body work_args_w_demands),
- \ worker_body -> mkLams work_args_w_demands (work_fn worker_body),
- map getIdDemandInfo work_args_w_demands)
+ = mk_ww_str wrap_args `thenUs` \ (work_args, wrap_fn, work_fn) ->
+ returnUs ( [idDemandInfo v | v <- work_args, isId v],
+ \ wrapper_body -> wrap_fn (mkVarApps wrapper_body work_args),
+ \ worker_body -> mkLams work_args (work_fn worker_body))
-- Empty case
mk_ww_str []
mk_ww_str (arg : ds)
- = case getIdDemandInfo arg of
+ | isTyVar arg
+ = mk_ww_str ds `thenUs` \ (worker_args, wrap_fn, work_fn) ->
+ returnUs (arg : worker_args, wrap_fn, work_fn)
+
+ | otherwise
+ = case idDemandInfo arg of
-- Absent case
WwLazy True ->
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 "mk_ww_str" setIdDemandInfo unpk_args cs
+ unpk_args_w_ds = zipWithEqual "mk_ww_str" set_worker_arg_info unpk_args cs
in
mk_ww_str (unpk_args_w_ds ++ ds) `thenUs` \ (worker_args, wrap_fn, work_fn) ->
returnUs (worker_args,
other_demand ->
mk_ww_str ds `thenUs` \ (worker_args, wrap_fn, work_fn) ->
returnUs (arg : worker_args, wrap_fn, work_fn)
+ where
+ -- If the wrapper argument is a one-shot lambda, then
+ -- so should (all) the corresponding worker arguments be
+ -- This bites when we do w/w on a case join point
+ set_worker_arg_info worker_arg demand = set_one_shot (setIdDemandInfo worker_arg demand)
+
+ set_one_shot | isOneShotLambda arg = setOneShotLambda
+ | otherwise = \x -> x
\end{code}
mkWWcpr body_ty NoCPRInfo
= returnUs (id, id, body_ty) -- Must be just the strictness transf.
-mkWWcpr body_ty (CPRInfo cpr_args)
- = getUniqueUs `thenUs` \ body_arg_uniq ->
- let
- body_var = mk_ww_local body_arg_uniq body_ty
- in
- cpr_reconstruct body_ty cpr_info' `thenUs` \reconst_fn ->
- cpr_flatten body_ty cpr_info' `thenUs` \(flatten_fn, res_ty) ->
- returnUs (reconst_fn, flatten_fn, res_ty)
- where
- -- We only make use of the outer level of CprInfo, otherwise we
- -- may lose laziness. :-( Hopefully, we will find a use for the
- -- extra info some day (e.g. creating versions specialized to
- -- the use made of the components of the result by the callee)
- cpr_info' = CPRInfo (map (const NoCPRInfo) cpr_args)
-\end{code}
-
-@cpr_flatten@ takes the result type produced by the body and the info
-from the CPR analysis and flattens the constructed product components.
-These are returned in an unboxed tuple.
+mkWWcpr body_ty ReturnsCPR
+ | not (isAlgType body_ty)
+ = WARN( True, text "mkWWcpr: non-algebraic body type" <+> ppr body_ty )
+ returnUs (id, id, body_ty)
-\begin{code}
-cpr_flatten :: Type -> CprInfo -> UniqSM (CoreExpr -> CoreExpr, Type)
-cpr_flatten ty cpr_info
- = mk_cpr_case (ty, cpr_info) `thenUs` \(res_id, tup_ids, flatten_exp) ->
+ | n_con_args == 1 && isUnLiftedType con_arg_ty1
+ -- Special case when there is a single result of unlifted type
+ = getUniquesUs 2 `thenUs` \ [work_uniq, arg_uniq] ->
let
- (unbx_tuple, unbx_tuple_ty) = mk_unboxed_tuple tup_ids
+ work_wild = mk_ww_local work_uniq body_ty
+ arg = mk_ww_local arg_uniq con_arg_ty1
in
- returnUs (\body -> Case body res_id [(DEFAULT, [], flatten_exp unbx_tuple)],
- unbx_tuple_ty)
-
-
-
-mk_cpr_case :: (Type, CprInfo) ->
- UniqSM (CoreBndr, -- Name of binder for this part of result
- [(CoreExpr, Type)], -- expressions for flattened result
- CoreExpr -> CoreExpr) -- add in code to flatten result
-
-mk_cpr_case (ty, NoCPRInfo)
- -- this component must be returned as a component of the unboxed tuple result
- = getUniqueUs `thenUs` \id_uniq ->
- let id_id = mk_ww_local id_uniq ty in
- returnUs (id_id, [(Var id_id, ty)], id)
-mk_cpr_case (ty, cpr_info@(CPRInfo ci_args))
- | isNewTyCon tycon -- a new type: under the coercions must be a
- -- constructed product
- = ASSERT ( null $ tail inst_con_arg_tys )
- 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
- new_exp_case = \var -> Case (Note (Coerce (idType arg) ty) (Var id_id))
- arg
- [(DEFAULT,[], exp var)]
- in
- returnUs (id_id, tup, new_exp_case)
-
- | otherwise -- a data type
- -- flatten components
- = mapUs mk_cpr_case (zip inst_con_arg_tys ci_args)
- `thenUs` \sub_builds ->
- getUniqueUs `thenUs` \id_uniq ->
- let id_id = mk_ww_local id_uniq ty
- (args, tup, exp) = unzip3 sub_builds
- -- not used: con_app = mkConApp data_con (map Var args)
- new_tup = concat tup
- new_exp_case = \var -> Case (Var id_id) (mkWildId ty)
- [(DataCon data_con, args,
- foldl (\e f -> f e) var exp)]
- in
- returnUs (id_id, new_tup, new_exp_case)
- where
- (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
+ returnUs (\ wkr_call -> Case wkr_call arg [(DEFAULT, [], mkConApp data_con (map Type tycon_arg_tys ++ [Var arg]))],
+ \ body -> Case body work_wild [(DataAlt data_con, [arg], Var arg)],
+ con_arg_ty1)
-\end{code}
-
-@cpr_reconstruct@ does the opposite of @cpr_flatten@. It takes the unboxed
-tuple produced by the worker and reconstructs the structured result.
-
-\begin{code}
-cpr_reconstruct :: Type -> CprInfo -> UniqSM (CoreExpr -> CoreExpr)
-cpr_reconstruct ty cpr_info
- = mk_cpr_let (ty,cpr_info) `thenUs` \(res_id, tup_ids, reconstruct_exp) ->
- returnUs (\worker -> Case worker (mkWildId $ worker_type tup_ids)
- [(DataCon $ unboxedTupleCon $ length tup_ids,
- tup_ids, reconstruct_exp $ Var res_id)])
-
- where
- worker_type ids = mkTyConApp (unboxedTupleTyCon (length ids)) (map idType ids)
-
-
-mk_cpr_let :: (Type, CprInfo) ->
- UniqSM (CoreBndr, -- Binder for this component of result
- [CoreBndr], -- Binders which will appear in worker's result
- CoreExpr -> CoreExpr) -- Code to produce structured result.
-mk_cpr_let (ty, NoCPRInfo)
- -- this component will appear explicitly in the unboxed tuple.
- = getUniqueUs `thenUs` \id_uniq ->
+ | otherwise -- The general case
+ = getUniquesUs (n_con_args + 2) `thenUs` \ uniqs ->
let
- id_id = mk_ww_local id_uniq ty
+ (wrap_wild : work_wild : args) = zipWith mk_ww_local uniqs (ubx_tup_ty : body_ty : con_arg_tys)
+ arg_vars = map Var args
+ ubx_tup_con = tupleCon Unboxed n_con_args
+ ubx_tup_ty = exprType ubx_tup_app
+ ubx_tup_app = mkConApp ubx_tup_con (map Type con_arg_tys ++ arg_vars)
+ con_app = mkConApp data_con (map Type tycon_arg_tys ++ arg_vars)
in
- returnUs (id_id, [id_id], id)
-
-mk_cpr_let (ty, cpr_info@(CPRInfo ci_args))
-
-{- Should not be needed now: mkWWfixup does this job
- | isNewTyCon tycon -- a new type: must coerce the argument to this type
- = ASSERT ( null $ tail inst_con_arg_tys )
- 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
- new_exp = \var -> exp (Let (NonRec id_id (Note (Coerce ty (idType arg)) (Var arg))) var)
- in
- returnUs (id_id, tup, new_exp)
-
- | otherwise -- a data type
- -- reconstruct components then apply data con
--}
- = mapUs mk_cpr_let (zip inst_con_arg_tys ci_args)
- `thenUs` \sub_builds ->
- getUniqueUs `thenUs` \id_uniq ->
- let id_id = mk_ww_local id_uniq ty
- (args, tup, exp) = unzip3 sub_builds
- con_app = mkConApp data_con $ (map Type tycon_arg_tys) ++ (map Var args)
- new_tup = concat tup
- new_exp = \var -> foldl (\e f -> f e) (Let (NonRec id_id con_app) var) exp
- in
- returnUs (id_id, new_tup, new_exp)
+ returnUs (\ wkr_call -> Case wkr_call wrap_wild [(DataAlt ubx_tup_con, args, con_app)],
+ \ body -> Case body work_wild [(DataAlt data_con, args, ubx_tup_app)],
+ ubx_tup_ty)
where
- (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
-
-
-splitProductType :: String -> Type -> (TyCon, [Type], DataCon, [Type])
- -- For a tiresome reason, the type might not look like a product type
- -- This happens when compiling the compiler! The module Name
- -- imports {-# SOURCE #-} TyCon and Id
- -- data Name = Name NameSort Unique OccName Provenance
- -- data NameSort = WiredInId Module Id | ...
- -- So Name does not look recursive (because Id is imported via a hi-boot file,
- -- which says nothing about Id's rep) but actually it is, because Ids have Names.
- -- Modules that *import* Name have a more complete view, see that Name is recursive,
- -- and therefore that it isn't a ProductType. This conflicts with the CPR info
- -- in exports from Name that say "do CPR".
- --
- -- Arguably we should regard Name as a product anyway because it isn't recursive
- -- via products all the way... but we don't have that info to hand, and even if
- -- we did this case might *still* arise.
-
- --
- -- So we hack our way out for now, by trusting the pragma that said "do CPR"
- -- that means we can't use splitProductType_maybe
-
-splitProductType fname ty
- = case splitAlgTyConApp_maybe ty of
- Just (tycon, tycon_args, (con:other_cons))
- | null other_cons && not (isExistentialDataCon con)
- -> WARN( not (isProductTyCon tycon),
- text "splitProductType hack: I happened!" <+> ppr ty )
- (tycon, tycon_args, con, dataConArgTys con tycon_args)
-
- Nothing -> pprPanic (fname ++ ": not a product") (ppr ty)
+ (tycon, tycon_arg_tys, data_con, con_arg_tys) = splitProductType "mkWWcpr" body_ty
+ n_con_args = length con_arg_tys
+ con_arg_ty1 = head con_arg_tys
\end{code}
-- A data type
= Case (Var arg)
(sanitiseCaseBndr arg)
- [(DataCon boxing_con, unpk_args, body)]
+ [(DataAlt boxing_con, unpk_args, body)]
sanitiseCaseBndr :: Id -> Id
-- The argument we are scrutinising has the right type to be
(unpk_arg:other_args) = unpk_args
mk_pk_let DataType arg boxing_con con_tys unpk_args body
- = Let (NonRec arg (Con (DataCon boxing_con) con_args)) body
+ = Let (NonRec arg (mkConApp boxing_con con_args)) body
where
con_args = map Type con_tys ++ map Var unpk_args
mk_ww_local uniq ty = mkSysLocal SLIT("ww") uniq ty
-
-mk_unboxed_tuple :: [(CoreExpr, Type)] -> (CoreExpr, Type)
-mk_unboxed_tuple contents
- = (mkConApp (unboxedTupleCon (length contents))
- (map (Type . snd) contents ++
- map fst contents),
- mkTyConApp (unboxedTupleTyCon (length contents))
- (map snd contents))
\end{code}
projects / ghc-hetmet.git / blobdiff