ConTag, fIRST_TAG,
mkDataCon,
dataConRepType, dataConSig, dataConName, dataConTag, dataConTyCon,
- dataConArgTys, dataConOrigArgTys,
- dataConRepArgTys,
- dataConFieldLabels, dataConStrictMarks,
+ dataConArgTys, dataConOrigArgTys, dataConInstOrigArgTys,
+ dataConRepArgTys, dataConTheta,
+ dataConFieldLabels, dataConStrictMarks,
dataConSourceArity, dataConRepArity,
dataConNumInstArgs, dataConId, dataConWrapId, dataConRepStrictness,
- isNullaryDataCon, isTupleCon, isUnboxedTupleCon, isDynDataCon,
- isExistentialDataCon,
+ isNullaryDataCon, isTupleCon, isUnboxedTupleCon,
+ isExistentialDataCon, classDataCon,
splitProductType_maybe, splitProductType,
-
- StrictnessMark(..), -- Representation visible to MkId only
- markedStrict, notMarkedStrict, markedUnboxed, maybeMarkedUnboxed
) where
#include "HsVersions.h"
import {-# SOURCE #-} Subst( substTy, mkTyVarSubst )
import CmdLineOpts ( opt_DictsStrict )
-import TysPrim
-import Type ( Type, ThetaType, TauType, ClassContext,
- mkForAllTys, mkFunTys, mkTyConApp,
- mkTyVarTys, mkDictTy,
- splitAlgTyConApp_maybe, classesToPreds
+import Type ( Type, TauType, ThetaType,
+ mkForAllTys, mkFunTys, mkTyConApp,
+ mkTyVarTys, mkPredTys, getClassPredTys_maybe,
+ splitTyConApp_maybe, repType
)
-import TyCon ( TyCon, tyConDataCons, isDataTyCon, isProductTyCon,
+import TyCon ( TyCon, tyConDataCons, tyConDataConsIfAvailable, isDataTyCon, isProductTyCon,
isTupleTyCon, isUnboxedTupleTyCon, isRecursiveTyCon )
-import Class ( classTyCon )
-import Name ( Name, NamedThing(..), nameUnique, isDynName, isLocallyDefined )
+import Class ( Class, classTyCon )
+import Name ( Name, NamedThing(..), nameUnique )
import Var ( TyVar, Id )
import FieldLabel ( FieldLabel )
import BasicTypes ( Arity )
-import Demand ( Demand, wwStrict, wwLazy )
+import Demand ( Demand, StrictnessMark(..), wwStrict, wwLazy )
import Outputable
import Unique ( Unique, Uniquable(..) )
import CmdLineOpts ( opt_UnboxStrictFields )
import PprType () -- Instances
-import UniqSet
-import Maybes ( maybeToBool )
import Maybe
-import Util ( assoc )
+import ListSetOps ( assoc )
+import Util ( zipEqual, zipWithEqual )
\end{code}
Stuff about data constructors
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Every constructor, C, comes with a
+Every constructor, C, comes with a
*wrapper*, called C, whose type is exactly what it looks like
in the source program. It is an ordinary function,
--
-- data Eq a => T a = forall b. Ord b => MkT a [b]
- dcRepType :: Type, -- Type of the constructor
+ dcRepType :: Type, -- Type of the constructor
-- forall ab . Ord b => a -> [b] -> MkT a
- -- (this is *not* of the constructor Id:
+ -- (this is *not* of the constructor Id:
-- see notes after this data type declaration)
-- The next six fields express the type of the constructor, in pieces
-- dcTyCon = T
dcTyVars :: [TyVar], -- Type vars and context for the data type decl
- dcTheta :: ClassContext,
+ -- These are ALWAYS THE SAME AS THE TYVARS
+ -- FOR THE PARENT TyCon. We occasionally rely on
+ -- this just to avoid redundant instantiation
+ dcTheta :: ThetaType,
- dcExTyVars :: [TyVar], -- Ditto for the context of the constructor,
- dcExTheta :: ClassContext, -- the existentially quantified stuff
+ dcExTyVars :: [TyVar], -- Ditto for the context of the constructor,
+ dcExTheta :: ThetaType, -- the existentially quantified stuff
dcOrigArgTys :: [Type], -- Original argument types
-- (before unboxing and flattening of
dcRepArgTys :: [Type], -- Final, representation argument types, after unboxing and flattening,
-- and including existential dictionaries
- dcTyCon :: TyCon, -- Result tycon
+ dcRepStrictness :: [Demand], -- One for each representation argument
+
+ dcTyCon :: TyCon, -- Result tycon
-- Now the strictness annotations and field labels of the constructor
- dcUserStricts :: [StrictnessMark],
- -- Strictness annotations, as placed on the data type defn,
- -- in the same order as the argument types;
- -- length = dataConSourceArity dataCon
-
- dcRealStricts :: [StrictnessMark],
- -- Strictness annotations as deduced by the compiler. May
- -- include some MarkedUnboxed fields that are merely MarkedStrict
- -- in dcUserStricts. Also includes the existential dictionaries.
+ dcStrictMarks :: [StrictnessMark],
+ -- Strictness annotations as deduced by the compiler.
+ -- Has no MarkedUserStrict; they have been changed to MarkedStrict
+ -- or MarkedUnboxed by the compiler.
+ -- *Includes the existential dictionaries*
-- length = length dcExTheta + dataConSourceArity dataCon
dcFields :: [FieldLabel],
%************************************************************************
%* *
-\subsection{Strictness indication}
-%* *
-%************************************************************************
-
-\begin{code}
-data StrictnessMark = MarkedStrict
- | MarkedUnboxed DataCon [Type]
- | NotMarkedStrict
-
-markedStrict = MarkedStrict
-notMarkedStrict = NotMarkedStrict
-markedUnboxed = MarkedUnboxed (panic "markedUnboxed1") (panic "markedUnboxed2")
-
-maybeMarkedUnboxed (MarkedUnboxed dc tys) = Just (dc,tys)
-maybeMarkedUnboxed other = Nothing
-\end{code}
-
-
-%************************************************************************
-%* *
\subsection{Instances}
%* *
%************************************************************************
\begin{code}
mkDataCon :: Name
-> [StrictnessMark] -> [FieldLabel]
- -> [TyVar] -> ClassContext
- -> [TyVar] -> ClassContext
+ -> [TyVar] -> ThetaType
+ -> [TyVar] -> ThetaType
-> [TauType] -> TyCon
-> Id -> Id
-> DataCon
-- Can get the tag from the TyCon
-mkDataCon name arg_stricts fields
- tyvars theta ex_tyvars ex_theta orig_arg_tys tycon
+mkDataCon name arg_stricts fields
+ tyvars theta ex_tyvars ex_theta orig_arg_tys tycon
work_id wrap_id
= ASSERT(length arg_stricts == length orig_arg_tys)
-- The 'stricts' passed to mkDataCon are simply those for the
con
where
con = MkData {dcName = name, dcUnique = nameUnique name,
- dcTyVars = tyvars, dcTheta = theta,
- dcOrigArgTys = orig_arg_tys,
+ dcTyVars = tyvars, dcTheta = theta,
+ dcOrigArgTys = orig_arg_tys,
dcRepArgTys = rep_arg_tys,
dcExTyVars = ex_tyvars, dcExTheta = ex_theta,
- dcRealStricts = all_stricts, dcUserStricts = user_stricts,
+ dcStrictMarks = real_stricts, dcRepStrictness = rep_arg_demands,
dcFields = fields, dcTag = tag, dcTyCon = tycon, dcRepType = ty,
dcId = work_id, dcWrapId = wrap_id}
- (real_arg_stricts, strict_arg_tyss)
- = unzip (zipWith (unbox_strict_arg_ty tycon) arg_stricts orig_arg_tys)
- rep_arg_tys = [mkDictTy cls tys | (cls,tys) <- ex_theta] ++ concat strict_arg_tyss
-
- ex_dict_stricts = map mk_dict_strict_mark ex_theta
- -- Add a strictness flag for the existential dictionary arguments
- all_stricts = ex_dict_stricts ++ real_arg_stricts
- user_stricts = ex_dict_stricts ++ arg_stricts
+ -- Strictness marks for source-args
+ -- *after unboxing choices*,
+ -- but *including existential dictionaries*
+ real_stricts = (map mk_dict_strict_mark ex_theta) ++
+ zipWithEqual "mkDataCon1" (chooseBoxingStrategy tycon)
+ orig_arg_tys arg_stricts
+
+ -- Representation arguments and demands
+ (rep_arg_demands, rep_arg_tys)
+ = unzip $ concat $
+ zipWithEqual "mkDataCon2" unbox_strict_arg_ty
+ real_stricts
+ (mkPredTys ex_theta ++ orig_arg_tys)
tag = assoc "mkDataCon" (tyConDataCons tycon `zip` [fIRST_TAG..]) con
- ty = mkForAllTys (tyvars ++ ex_tyvars)
+ ty = mkForAllTys (tyvars ++ ex_tyvars)
(mkFunTys rep_arg_tys result_ty)
-- NB: the existential dict args are already in rep_arg_tys
result_ty = mkTyConApp tycon (mkTyVarTys tyvars)
-mk_dict_strict_mark (clas,tys)
- | opt_DictsStrict &&
- -- Don't mark newtype things as strict!
+mk_dict_strict_mark pred
+ | opt_DictsStrict, -- Don't mark newtype things as strict!
+ Just (clas,_) <- getClassPredTys_maybe pred,
isDataTyCon (classTyCon clas) = MarkedStrict
| otherwise = NotMarkedStrict
\end{code}
dataConFieldLabels = dcFields
dataConStrictMarks :: DataCon -> [StrictnessMark]
-dataConStrictMarks = dcRealStricts
+dataConStrictMarks = dcStrictMarks
-- Number of type-instantiation arguments
-- All the remaining arguments of the DataCon are (notionally)
isNullaryDataCon con = dataConRepArity con == 0
dataConRepStrictness :: DataCon -> [Demand]
- -- Give the demands on the arguments of a
+ -- Give the demands on the arguments of a
-- Core constructor application (Con dc args)
-dataConRepStrictness dc
- = go (dcRealStricts dc)
- where
- go [] = []
- go (MarkedStrict : ss) = wwStrict : go ss
- go (NotMarkedStrict : ss) = wwLazy : go ss
- go (MarkedUnboxed con _ : ss) = go (dcRealStricts con ++ ss)
+dataConRepStrictness dc = dcRepStrictness dc
-dataConSig :: DataCon -> ([TyVar], ClassContext,
- [TyVar], ClassContext,
+dataConSig :: DataCon -> ([TyVar], ThetaType,
+ [TyVar], ThetaType,
[TauType], TyCon)
dataConSig (MkData {dcTyVars = tyvars, dcTheta = theta,
dcOrigArgTys = arg_tys, dcTyCon = tycon})
= (tyvars, theta, ex_tyvars, ex_theta, arg_tys, tycon)
-dataConArgTys :: DataCon
+dataConArgTys :: DataCon
-> [Type] -- Instantiated at these types
-- NB: these INCLUDE the existentially quantified arg types
-> [Type] -- Needs arguments of these types
-- but EXCLUDE the data-decl context which is discarded
-- It's all post-flattening etc; this is a representation type
-dataConArgTys (MkData {dcRepArgTys = arg_tys, dcTyVars = tyvars,
+dataConArgTys (MkData {dcRepArgTys = arg_tys, dcTyVars = tyvars,
+ dcExTyVars = ex_tyvars}) inst_tys
+ = map (substTy (mkTyVarSubst (tyvars ++ ex_tyvars) inst_tys)) arg_tys
+
+dataConTheta :: DataCon -> ThetaType
+dataConTheta dc = dcTheta dc
+
+-- And the same deal for the original arg tys:
+
+dataConInstOrigArgTys :: DataCon -> [Type] -> [Type]
+dataConInstOrigArgTys (MkData {dcOrigArgTys = arg_tys, dcTyVars = tyvars,
dcExTyVars = ex_tyvars}) inst_tys
= map (substTy (mkTyVarSubst (tyvars ++ ex_tyvars) inst_tys)) arg_tys
\end{code}
These two functions get the real argument types of the constructor,
-without substituting for any type variables.
+without substituting for any type variables.
dataConOrigArgTys returns the arg types of the wrapper, excluding all dictionary args.
isExistentialDataCon :: DataCon -> Bool
isExistentialDataCon (MkData {dcExTyVars = tvs}) = not (null tvs)
-
-isDynDataCon :: DataCon -> Bool
-isDynDataCon con = isDynName (dataConName con)
\end{code}
+\begin{code}
+classDataCon :: Class -> DataCon
+classDataCon clas = case tyConDataCons (classTyCon clas) of
+ (dict_constr:no_more) -> ASSERT( null no_more ) dict_constr
+\end{code}
+
%************************************************************************
%* *
\subsection{Splitting products}
%* *
%************************************************************************
-\begin{code}
+\begin{code}
splitProductType_maybe
:: Type -- A product type, perhaps
-> Maybe (TyCon, -- The type constructor
DataCon, -- The data constructor
[Type]) -- Its *representation* arg types
- -- Returns (Just ...) for any
+ -- Returns (Just ...) for any
+ -- concrete (i.e. constructors visible)
-- single-constructor
-- not existentially quantified
-- type whether a data type or a new type
-- it through till someone finds it's important.
splitProductType_maybe ty
- = case splitAlgTyConApp_maybe ty of
- Just (tycon,ty_args,[data_con])
- | isProductTyCon tycon -- Includes check for non-existential
+ = case splitTyConApp_maybe ty of
+ Just (tycon,ty_args)
+ | isProductTyCon tycon -- Includes check for non-existential,
+ -- and for constructors visible
-> Just (tycon, ty_args, data_con, dataConArgTys data_con ty_args)
+ where
+ data_con = head (tyConDataConsIfAvailable tycon)
other -> Nothing
splitProductType str ty
-- We attempt to unbox/unpack a strict field when either:
-- (i) The tycon is imported, and the field is marked '! !', or
--- (ii) The tycon is defined in this module, the field is marked '!',
+-- (ii) The tycon is defined in this module, the field is marked '!',
-- and the -funbox-strict-fields flag is on.
--
-- This ensures that if we compile some modules with -funbox-strict-fields and
-- some without, the compiler doesn't get confused about the constructor
-- representations.
-unbox_strict_arg_ty :: TyCon -> StrictnessMark -> Type -> (StrictnessMark, [Type])
-
-unbox_strict_arg_ty tycon strict_mark ty
- | case strict_mark of
- NotMarkedStrict -> False
- MarkedUnboxed _ _ -> True
- MarkedStrict -> opt_UnboxStrictFields &&
- isLocallyDefined tycon &&
- maybeToBool maybe_product &&
- not (isRecursiveTyCon tycon) &&
- isDataTyCon arg_tycon
- -- We can't look through newtypes in arguments (yet)
- = (MarkedUnboxed con arg_tys, arg_tys)
-
- | otherwise
- = (strict_mark, [ty])
-
+chooseBoxingStrategy :: TyCon -> Type -> StrictnessMark -> StrictnessMark
+ -- Transforms any MarkedUserStricts into MarkUnboxed or MarkedStrict
+chooseBoxingStrategy tycon arg_ty strict
+ = case strict of
+ MarkedUserStrict
+ | opt_UnboxStrictFields
+ && unbox arg_ty -> MarkedUnboxed
+ | otherwise -> MarkedStrict
+ other -> strict
+ where
+ -- beware: repType will go into a loop if we try this on a recursive
+ -- type (for reasons unknown...), hence the check for recursion below.
+ unbox ty =
+ case splitTyConApp_maybe ty of
+ Nothing -> False
+ Just (arg_tycon, _)
+ | isRecursiveTyCon arg_tycon -> False
+ | otherwise ->
+ case splitTyConApp_maybe (repType ty) of
+ Nothing -> False
+ Just (arg_tycon, _) -> isProductTyCon arg_tycon
+
+unbox_strict_arg_ty
+ :: StrictnessMark -- After strategy choice; can't be MkaredUserStrict
+ -> Type -- Source argument type
+ -> [(Demand,Type)] -- Representation argument types and demamds
+
+unbox_strict_arg_ty NotMarkedStrict ty = [(wwLazy, ty)]
+unbox_strict_arg_ty MarkedStrict ty = [(wwStrict, ty)]
+unbox_strict_arg_ty MarkedUnboxed ty
+ = zipEqual "unbox_strict_arg_ty" (dataConRepStrictness arg_data_con) arg_tys
where
- maybe_product = splitProductType_maybe ty
- Just (arg_tycon, _, con, arg_tys) = maybe_product
+ (_, _, arg_data_con, arg_tys)
+ = splitProductType "unbox_strict_arg_ty" (repType ty)
\end{code}
-
-