%
-% (c) The GRASP/AQUA Project, Glasgow University, 1993-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
%
\section[IdInfo]{@IdInfos@: Non-essential information about @Ids@}
Haskell. [WDP 94/11])
\begin{code}
-#include "HsVersions.h"
-
module IdInfo (
- IdInfo, -- abstract
+ IdInfo, -- Abstract
+
noIdInfo,
- boringIdInfo,
ppIdInfo,
- applySubstToIdInfo, apply_to_IdInfo, -- not for general use, please
- OptIdInfo(..), -- class; for convenience only
- -- all the *Infos herein are instances of it
+ -- Arity
+ ArityInfo(..),
+ exactArity, atLeastArity, unknownArity,
+ arityInfo, setArityInfo, ppArityInfo, arityLowerBound,
- -- component "id infos"; also abstract:
- SrcLoc,
- getSrcLocIdInfo,
+ -- Strictness
+ StrictnessInfo(..), -- Non-abstract
+ workerExists, mkStrictnessInfo, mkBottomStrictnessInfo,
+ noStrictnessInfo, bottomIsGuaranteed, strictnessInfo,
+ ppStrictnessInfo, setStrictnessInfo,
- ArityInfo,
- mkArityInfo, unknownArity, arityMaybe,
+ -- Unfolding
+ unfoldingInfo, setUnfoldingInfo,
- DemandInfo,
- mkDemandInfo,
- willBeDemanded,
+ -- DemandInfo
+ demandInfo, setDemandInfo,
- MatchEnv, -- the SpecEnv
- StrictnessInfo(..), -- non-abstract
- Demand(..), -- non-abstract
+ -- Inline prags
+ InlinePragInfo(..), OccInfo(..),
+ inlinePragInfo, setInlinePragInfo, notInsideLambda,
- wwLazy, wwStrict, wwUnpack, wwPrim, wwEnum,
- indicatesWorker, nonAbsentArgs,
- mkStrictnessInfo, mkBottomStrictnessInfo,
- getWrapperArgTypeCategories,
- getWorkerId,
- workerExists,
- bottomIsGuaranteed,
+ -- Specialisation
+ IdSpecEnv, specInfo, setSpecInfo,
- mkUnfolding,
- noInfo_UF, getInfo_UF, addInfo_UF, -- to avoid instance virus
+ -- Update
+ UpdateInfo, UpdateSpec,
+ mkUpdateInfo, updateInfo, updateInfoMaybe, ppUpdateInfo, setUpdateInfo,
- UpdateInfo,
- mkUpdateInfo,
- UpdateSpec(..),
- updateInfoMaybe,
-
- DeforestInfo(..),
+ -- CAF info
+ CafInfo(..), cafInfo, setCafInfo, ppCafInfo,
+ ) where
- ArgUsageInfo,
- ArgUsage(..),
- ArgUsageType(..),
- mkArgUsageInfo,
- getArgUsage,
+#include "HsVersions.h"
- FBTypeInfo,
- FBType(..),
- FBConsum(..),
- FBProd(..),
- mkFBTypeInfo,
- getFBType
- ) where
+import {-# SOURCE #-} CoreUnfold ( Unfolding, noUnfolding )
+import {-# SOURCE #-} CoreSyn ( CoreExpr )
-import Ubiq
-
-import IdLoop -- IdInfo is a dependency-loop ranch, and
- -- we break those loops by using IdLoop and
- -- *not* importing much of anything else,
- -- except from the very general "utils".
-
-import CmdLineOpts ( opt_OmitInterfacePragmas )
-import Maybes ( firstJust )
-import MatchEnv ( nullMEnv, isEmptyMEnv, mEnvToList )
-import Outputable ( ifPprInterface, Outputable(..){-instances-} )
-import PprStyle ( PprStyle(..) )
-import Pretty
-import SrcLoc ( mkUnknownSrcLoc )
-import Type ( eqSimpleTy )
-import Util ( mapAccumL, panic, assertPanic, pprPanic )
-
-applySubstToTy = panic "IdInfo.applySubstToTy"
-splitTypeWithDictsAsArgs = panic "IdInfo.splitTypeWithDictsAsArgs"
-showTypeCategory = panic "IdInfo.showTypeCategory"
-mkFormSummary = panic "IdInfo.mkFormSummary"
-occurAnalyseGlobalExpr = panic "IdInfo.occurAnalyseGlobalExpr"
-isWrapperFor = panic "IdInfo.isWrapperFor"
-pprCoreUnfolding = panic "IdInfo.pprCoreUnfolding"
+import SpecEnv ( SpecEnv, emptySpecEnv )
+import Demand ( Demand, isLazy, wwLazy, pprDemands )
+import Outputable
\end{code}
An @IdInfo@ gives {\em optional} information about an @Id@. If
\begin{code}
data IdInfo
- = IdInfo
- ArityInfo -- Its arity
-
- DemandInfo -- Whether or not it is definitely
- -- demanded
-
- (MatchEnv [Type] CoreExpr)
- -- Specialisations of this function which exist
- -- This corresponds to a SpecEnv which we do
- -- not import directly to avoid loop
-
- StrictnessInfo -- Strictness properties, notably
- -- how to conjure up "worker" functions
-
- UnfoldingDetails -- Its unfolding; for locally-defined
- -- things, this can *only* be NoUnfoldingDetails
-
- UpdateInfo -- Which args should be updated
-
- DeforestInfo -- Whether its definition should be
- -- unfolded during deforestation
-
- ArgUsageInfo -- how this Id uses its arguments
-
- FBTypeInfo -- the Foldr/Build W/W property of this function.
-
- SrcLoc -- Source location of definition
-
- -- ToDo: SrcLoc is in FullNames too (could rm?) but it
- -- is needed here too for things like ConstMethodIds and the
- -- like, which don't have full-names of their own Mind you,
- -- perhaps the Name for a constant method could give the
- -- class/type involved?
+ = IdInfo {
+ arityInfo :: ArityInfo, -- Its arity
+ demandInfo :: Demand, -- Whether or not it is definitely demanded
+ specInfo :: IdSpecEnv, -- Specialisations of this function which exist
+ strictnessInfo :: StrictnessInfo, -- Strictness properties
+ unfoldingInfo :: Unfolding, -- Its unfolding
+ updateInfo :: UpdateInfo, -- Which args should be updated
+ cafInfo :: CafInfo,
+ inlinePragInfo :: !InlinePragInfo -- Inline pragmas
+ }
\end{code}
-\begin{code}
-noIdInfo = IdInfo noInfo noInfo noInfo noInfo noInfo_UF
- noInfo noInfo noInfo noInfo mkUnknownSrcLoc
-
--- "boring" means: nothing to put in interface
-boringIdInfo (IdInfo UnknownArity
- UnknownDemand
- specenv
- strictness
- unfolding
- NoUpdateInfo
- Don'tDeforest
- _ {- arg_usage: currently no interface effect -}
- _ {- no f/b w/w -}
- _ {- src_loc: no effect on interfaces-}
- )
- | null (mEnvToList specenv)
- && boring_strictness strictness
- && boring_unfolding unfolding
- = True
- where
- boring_strictness NoStrictnessInfo = True
- boring_strictness BottomGuaranteed = False
- boring_strictness (StrictnessInfo wrap_args _) = all_present_WwLazies wrap_args
-
- boring_unfolding NoUnfoldingDetails = True
- boring_unfolding _ = False
-
-boringIdInfo _ = False
-
-pp_NONE = ppPStr SLIT("_N_")
-\end{code}
+Setters
-Simply turgid. But BE CAREFUL: don't @apply_to_Id@ if that @Id@
-will in turn @apply_to_IdInfo@ of the self-same @IdInfo@. (A very
-nasty loop, friends...)
\begin{code}
-apply_to_IdInfo ty_fn idinfo@(IdInfo arity demand spec strictness unfold
- update deforest arg_usage fb_ww srcloc)
- | isEmptyMEnv spec
- = idinfo
- | otherwise
- = panic "IdInfo:apply_to_IdInfo"
-{- LATER:
- let
- new_spec = apply_spec spec
-
- -- NOT a good idea:
- -- apply_strict strictness `thenLft` \ new_strict ->
- -- apply_wrap wrap `thenLft` \ new_wrap ->
- in
- IdInfo arity demand new_spec strictness unfold
- update deforest arg_usage fb_ww srcloc
- where
- apply_spec (SpecEnv is)
- = SpecEnv (map do_one is)
- where
- do_one (SpecInfo ty_maybes ds spec_id)
- = --apply_to_Id ty_fn spec_id `thenLft` \ new_spec_id ->
- SpecInfo (map apply_to_maybe ty_maybes) ds spec_id
- where
- apply_to_maybe Nothing = Nothing
- apply_to_maybe (Just ty) = Just (ty_fn ty)
--}
-
-{- NOT a good idea;
- apply_strict info@NoStrictnessInfo = returnLft info
- apply_strict BottomGuaranteed = ???
- apply_strict (StrictnessInfo wrap_arg_info id_maybe)
- = (case id_maybe of
- Nothing -> returnLft Nothing
- Just xx -> applySubstToId subst xx `thenLft` \ new_xx ->
- returnLft (Just new_xx)
- ) `thenLft` \ new_id_maybe ->
- returnLft (StrictnessInfo wrap_arg_info new_id_maybe)
--}
+setUpdateInfo ud info = info { updateInfo = ud }
+setDemandInfo dd info = info { demandInfo = dd }
+setStrictnessInfo st info = info { strictnessInfo = st }
+setSpecInfo sp info = info { specInfo = sp }
+setArityInfo ar info = info { arityInfo = ar }
+setInlinePragInfo pr info = info { inlinePragInfo = pr }
+setUnfoldingInfo uf info = info { unfoldingInfo = uf }
+setCafInfo cf info = info { cafInfo = cf }
\end{code}
-Variant of the same thing for the typechecker.
+
\begin{code}
-applySubstToIdInfo s0 (IdInfo arity demand spec strictness unfold
- update deforest arg_usage fb_ww srcloc)
- = panic "IdInfo:applySubstToIdInfo"
-{- LATER:
- case (apply_spec s0 spec) of { (s1, new_spec) ->
- (s1, IdInfo arity demand new_spec strictness unfold update deforest arg_usage fb_ww srcloc) }
- where
- apply_spec s0 (SpecEnv is)
- = case (mapAccumL do_one s0 is) of { (s1, new_is) ->
- (s1, SpecEnv new_is) }
- where
- do_one s0 (SpecInfo ty_maybes ds spec_id)
- = case (mapAccumL apply_to_maybe s0 ty_maybes) of { (s1, new_maybes) ->
- (s1, SpecInfo new_maybes ds spec_id) }
- where
- apply_to_maybe s0 Nothing = (s0, Nothing)
- apply_to_maybe s0 (Just ty)
- = case (applySubstToTy s0 ty) of { (s1, new_ty) ->
- (s1, Just new_ty) }
--}
+noIdInfo = IdInfo {
+ arityInfo = UnknownArity,
+ demandInfo = wwLazy,
+ specInfo = emptySpecEnv,
+ strictnessInfo = NoStrictnessInfo,
+ unfoldingInfo = noUnfolding,
+ updateInfo = NoUpdateInfo,
+ cafInfo = MayHaveCafRefs,
+ inlinePragInfo = NoInlinePragInfo
+ }
\end{code}
\begin{code}
-ppIdInfo :: PprStyle
- -> Id -- The Id for which we're printing this IdInfo
- -> Bool -- True <=> print specialisations, please
- -> (Id -> Id) -- to look up "better Ids" w/ better IdInfos;
- -> IdEnv UnfoldingDetails
- -- inlining info for top-level fns in this module
- -> IdInfo -- see MkIface notes
- -> Pretty
-
-ppIdInfo sty for_this_id specs_please better_id_fn inline_env
- i@(IdInfo arity demand specenv strictness unfold update deforest arg_usage fbtype srcloc)
- | boringIdInfo i
- = ppPStr SLIT("_NI_")
-
- | otherwise
- = let
- stuff = ppCat [
- -- order is important!:
- ppInfo sty better_id_fn arity,
- ppInfo sty better_id_fn update,
- ppInfo sty better_id_fn deforest,
-
- pp_strictness sty (Just for_this_id)
- better_id_fn inline_env strictness,
-
- if bottomIsGuaranteed strictness
- then pp_NONE
- else pp_unfolding sty for_this_id inline_env unfold,
-
- if specs_please
- then ppSpecs sty (not (isDataCon for_this_id))
- better_id_fn inline_env (mEnvToList specenv)
- else pp_NONE,
-
- -- DemandInfo needn't be printed since it has no effect on interfaces
- ppInfo sty better_id_fn demand,
- ppInfo sty better_id_fn fbtype
- ]
- in
- case sty of
- PprInterface -> if opt_OmitInterfacePragmas
- then ppNil
- else stuff
- _ -> stuff
+ppIdInfo :: IdInfo -> SDoc
+ppIdInfo (IdInfo {arityInfo,
+ demandInfo,
+ specInfo,
+ strictnessInfo,
+ unfoldingInfo,
+ updateInfo,
+ cafInfo,
+ inlinePragInfo})
+ = hsep [
+ ppArityInfo arityInfo,
+ ppUpdateInfo updateInfo,
+ ppStrictnessInfo strictnessInfo,
+ ppr demandInfo,
+ ppCafInfo cafInfo
+ -- Inline pragma printed out with all binders; see PprCore.pprIdBndr
+ ]
\end{code}
%************************************************************************
%* *
-\subsection[OptIdInfo-class]{The @OptIdInfo@ class (keeps things tidier)}
+\subsection[arity-IdInfo]{Arity info about an @Id@}
%* *
%************************************************************************
+For locally-defined Ids, the code generator maintains its own notion
+of their arities; so it should not be asking... (but other things
+besides the code-generator need arity info!)
+
\begin{code}
-class OptIdInfo a where
- noInfo :: a
- getInfo :: IdInfo -> a
- addInfo :: IdInfo -> a -> IdInfo
- -- By default, "addInfo" will not overwrite
- -- "info" with "non-info"; look at any instance
- -- to see an example.
- ppInfo :: PprStyle -> (Id -> Id) -> a -> Pretty
-\end{code}
+data ArityInfo
+ = UnknownArity -- No idea
+ | ArityExactly Int -- Arity is exactly this
+ | ArityAtLeast Int -- Arity is this or greater
-%************************************************************************
-%* *
-\subsection[srcloc-IdInfo]{Source-location info in an @IdInfo@}
-%* *
-%************************************************************************
+exactArity = ArityExactly
+atLeastArity = ArityAtLeast
+unknownArity = UnknownArity
-Not used much, but...
-\begin{code}
-getSrcLocIdInfo (IdInfo _ _ _ _ _ _ _ _ _ src_loc) = src_loc
+arityLowerBound :: ArityInfo -> Int
+arityLowerBound UnknownArity = 0
+arityLowerBound (ArityAtLeast n) = n
+arityLowerBound (ArityExactly n) = n
+
+
+ppArityInfo UnknownArity = empty
+ppArityInfo (ArityExactly arity) = hsep [ptext SLIT("__A"), int arity]
+ppArityInfo (ArityAtLeast arity) = hsep [ptext SLIT("__AL"), int arity]
\end{code}
%************************************************************************
%* *
-\subsection[arity-IdInfo]{Arity info about an @Id@}
+\subsection{Inline-pragma information}
%* *
%************************************************************************
\begin{code}
-data ArityInfo
- = UnknownArity -- no idea
- | ArityExactly Int -- arity is exactly this
-\end{code}
-
-\begin{code}
-mkArityInfo = ArityExactly
-unknownArity = UnknownArity
+data InlinePragInfo
+ = NoInlinePragInfo
-arityMaybe :: ArityInfo -> Maybe Int
+ | IAmASpecPragmaId -- Used for spec-pragma Ids; don't discard or inline
-arityMaybe UnknownArity = Nothing
-arityMaybe (ArityExactly i) = Just i
-\end{code}
+ | IWantToBeINLINEd -- User INLINE pragma
+ | IMustNotBeINLINEd -- User NOINLINE pragma
-\begin{code}
-instance OptIdInfo ArityInfo where
- noInfo = UnknownArity
+ | IAmALoopBreaker -- Used by the occurrence analyser to mark loop-breakers
+ -- in a group of recursive definitions
- getInfo (IdInfo arity _ _ _ _ _ _ _ _ _) = arity
+ | ICanSafelyBeINLINEd -- Used by the occurrence analyser to mark things
+ -- that manifesly occur once, not inside SCCs,
+ -- not in constructor arguments
- addInfo id_info UnknownArity = id_info
- addInfo (IdInfo _ a c d e f g h i j) arity = IdInfo arity a c d e f g h i j
+ OccInfo -- Says whether the occurrence is inside a lambda
+ -- If so, must only substitute WHNFs
- ppInfo sty _ UnknownArity = ifPprInterface sty pp_NONE
- ppInfo sty _ (ArityExactly arity) = ppCat [ppPStr SLIT("_A_"), ppInt arity]
-\end{code}
+ Bool -- False <=> occurs in more than one case branch
+ -- If so, there's a code-duplication issue
-%************************************************************************
-%* *
-\subsection[demand-IdInfo]{Demand info about an @Id@}
-%* *
-%************************************************************************
+ | IAmDead -- Marks unused variables. Sometimes useful for
+ -- lambda and case-bound variables.
-Whether a value is certain to be demanded or not. (This is the
-information that is computed by the ``front-end'' of the strictness
-analyser.)
+ | IMustBeINLINEd -- Absolutely must inline; used for PrimOps and
+ -- constructors only.
-This information is only used within a module, it is not exported
-(obviously).
+instance Outputable InlinePragInfo where
+ ppr NoInlinePragInfo = empty
+ ppr IMustBeINLINEd = ptext SLIT("__UU")
+ ppr IWantToBeINLINEd = ptext SLIT("__U")
+ ppr IMustNotBeINLINEd = ptext SLIT("__Unot")
+ ppr IAmALoopBreaker = ptext SLIT("__Ux")
+ ppr IAmDead = ptext SLIT("__Ud")
+ ppr (ICanSafelyBeINLINEd _ _) = ptext SLIT("__Us")
+ ppr IAmASpecPragmaId = ptext SLIT("__US")
-\begin{code}
-data DemandInfo
- = UnknownDemand
- | DemandedAsPer Demand
+instance Show InlinePragInfo where
+ showsPrec p prag = showsPrecSDoc p (ppr prag)
\end{code}
+The @IMustNotBeDiscarded@ exists only to make Ids that are
+on the *LHS* of bindings created by SPECIALISE pragmas;
+eg: s = f Int d
+The SpecPragmaId is never itself mentioned; it
+exists solely so that the specialiser will find
+the call to f, and make specialised version of it.
+The SpecPragmaId binding is discarded by the specialiser
+when it gathers up overloaded calls.
+Meanwhile, it is not discarded as dead code.
+
\begin{code}
-mkDemandInfo :: Demand -> DemandInfo
-mkDemandInfo demand = DemandedAsPer demand
+data OccInfo
+ = StrictOcc -- Occurs syntactically strictly;
+ -- i.e. in a function position or case scrutinee
-willBeDemanded :: DemandInfo -> Bool
-willBeDemanded (DemandedAsPer demand) = isStrict demand
-willBeDemanded _ = False
-\end{code}
+ | LazyOcc -- Not syntactically strict (*even* that of a strict function)
+ -- or in a case branch where there's more than one alternative
-\begin{code}
-instance OptIdInfo DemandInfo where
- noInfo = UnknownDemand
-
- getInfo (IdInfo _ demand _ _ _ _ _ _ _ _) = demand
-
-{- DELETED! If this line is in, there is no way to
- nuke a DemandInfo, and we have to be able to do that
- when floating let-bindings around
- addInfo id_info UnknownDemand = id_info
--}
- addInfo (IdInfo a _ c d e f g h i j) demand = IdInfo a demand c d e f g h i j
-
- ppInfo PprInterface _ _ = ppNil
- ppInfo sty _ UnknownDemand = ppStr "{-# L #-}"
- ppInfo sty _ (DemandedAsPer info)
- = ppCat [ppStr "{-#", ppStr (showList [info] ""), ppStr "#-}"]
+ | InsideLam -- Inside a non-linear lambda (that is, a lambda which
+ -- is sure to be instantiated only once).
+ -- Substituting a redex for this occurrence is
+ -- dangerous because it might duplicate work.
+
+instance Outputable OccInfo where
+ ppr StrictOcc = text "s"
+ ppr LazyOcc = empty
+ ppr InsideLam = text "l"
+
+
+notInsideLambda :: OccInfo -> Bool
+notInsideLambda StrictOcc = True
+notInsideLambda LazyOcc = True
+notInsideLambda InsideLam = False
\end{code}
%************************************************************************
%* *
%************************************************************************
-See SpecEnv.lhs
+A @IdSpecEnv@ holds details of an @Id@'s specialisations.
\begin{code}
-instance OptIdInfo (MatchEnv [Type] CoreExpr) where
- noInfo = nullMEnv
+type IdSpecEnv = SpecEnv CoreExpr
+\end{code}
- getInfo (IdInfo _ _ spec _ _ _ _ _ _ _) = spec
+For example, if \tr{f}'s @SpecEnv@ contains the mapping:
+\begin{verbatim}
+ [List a, b] ===> (\d -> f' a b)
+\end{verbatim}
+then when we find an application of f to matching types, we simply replace
+it by the matching RHS:
+\begin{verbatim}
+ f (List Int) Bool ===> (\d -> f' Int Bool)
+\end{verbatim}
+All the stuff about how many dictionaries to discard, and what types
+to apply the specialised function to, are handled by the fact that the
+SpecEnv contains a template for the result of the specialisation.
- addInfo id_info spec | null (mEnvToList spec) = id_info
- addInfo (IdInfo a b _ d e f g h i j) spec = IdInfo a b spec d e f g h i j
+There is one more exciting case, which is dealt with in exactly the same
+way. If the specialised value is unboxed then it is lifted at its
+definition site and unlifted at its uses. For example:
+
+ pi :: forall a. Num a => a
+
+might have a specialisation
+
+ [Int#] ===> (case pi' of Lift pi# -> pi#)
+
+where pi' :: Lift Int# is the specialised version of pi.
- ppInfo sty better_id_fn spec
- = ppSpecs sty True better_id_fn nullIdEnv (mEnvToList spec)
-ppSpecs sty print_spec_id_info better_id_fn inline_env spec_env
- = if null spec_env then ppNil else panic "IdInfo:ppSpecs"
-\end{code}
%************************************************************************
%* *
-- Useful for "error" and other disguised
-- variants thereof.
- | StrictnessInfo [Demand] -- the main stuff; see below.
- (Maybe Id) -- worker's Id, if applicable.
-\end{code}
-
-This type is also actually used in the strictness analyser:
-\begin{code}
-data Demand
- = WwLazy -- Argument is lazy as far as we know
- MaybeAbsent -- (does not imply worker's existence [etc]).
- -- If MaybeAbsent == True, then it is
- -- *definitely* lazy. (NB: Absence implies
- -- a worker...)
-
- | WwStrict -- Argument is strict but that's all we know
- -- (does not imply worker's existence or any
- -- calling-convention magic)
-
- | WwUnpack -- Argument is strict & a single-constructor
- [Demand] -- type; its constituent parts (whose StrictInfos
- -- are in the list) should be passed
- -- as arguments to the worker.
-
- | WwPrim -- Argument is of primitive type, therefore
- -- strict; doesn't imply existence of a worker;
- -- argument should be passed as is to worker.
-
- | WwEnum -- Argument is strict & an enumeration type;
- -- an Int# representing the tag (start counting
- -- at zero) should be passed to the worker.
- deriving (Eq, Ord)
- -- we need Eq/Ord to cross-chk update infos in interfaces
-
-type MaybeAbsent = Bool -- True <=> not even used
+ | StrictnessInfo [Demand]
+ Bool -- True <=> there is a worker. There might not be, even for a
+ -- strict function, because:
+ -- (a) the function might be small enough to inline,
+ -- so no need for w/w split
+ -- (b) the strictness info might be "SSS" or something, so no w/w split.
--- versions that don't worry about Absence:
-wwLazy = WwLazy False
-wwStrict = WwStrict
-wwUnpack xs = WwUnpack xs
-wwPrim = WwPrim
-wwEnum = WwEnum
+ -- Worker's Id, if applicable, and a list of the constructors
+ -- mentioned by the wrapper. This is necessary so that the
+ -- renamer can slurp them in. Without this info, the renamer doesn't
+ -- know which data types to slurp in concretely. Remember, for
+ -- strict things we don't put the unfolding in the interface file, to save space.
+ -- This constructor list allows the renamer to behave much as if the
+ -- unfolding *was* in the interface file.
\end{code}
\begin{code}
-mkStrictnessInfo :: [Demand] -> Maybe Id -> StrictnessInfo
+mkStrictnessInfo :: [Demand] -> Bool -> StrictnessInfo
-mkStrictnessInfo [] _ = NoStrictnessInfo
-mkStrictnessInfo xs wrkr = StrictnessInfo xs wrkr
+mkStrictnessInfo xs has_wrkr
+ | all isLazy xs = NoStrictnessInfo -- Uninteresting
+ | otherwise = StrictnessInfo xs has_wrkr
+noStrictnessInfo = NoStrictnessInfo
mkBottomStrictnessInfo = BottomGuaranteed
bottomIsGuaranteed BottomGuaranteed = True
bottomIsGuaranteed other = False
-getWrapperArgTypeCategories
- :: Type -- wrapper's type
- -> StrictnessInfo -- strictness info about its args
- -> Maybe String
-
-getWrapperArgTypeCategories _ NoStrictnessInfo = Nothing
-getWrapperArgTypeCategories _ BottomGuaranteed
- = trace "getWrapperArgTypeCategories:BottomGuaranteed!" Nothing -- wrong
-getWrapperArgTypeCategories _ (StrictnessInfo [] _) = Nothing
+ppStrictnessInfo NoStrictnessInfo = empty
+ppStrictnessInfo BottomGuaranteed = ptext SLIT("__bot")
-getWrapperArgTypeCategories ty (StrictnessInfo arg_info _)
- = Just (mkWrapperArgTypeCategories ty arg_info)
-
-workerExists :: StrictnessInfo -> Bool
-workerExists (StrictnessInfo _ (Just worker_id)) = True
-workerExists other = False
-
-getWorkerId :: StrictnessInfo -> Id
-
-getWorkerId (StrictnessInfo _ (Just worker_id)) = worker_id
-#ifdef DEBUG
-getWorkerId junk = pprPanic "getWorkerId: " (ppInfo PprDebug (\x->x) junk)
-#endif
+ppStrictnessInfo (StrictnessInfo wrapper_args wrkr_maybe)
+ = hsep [ptext SLIT("__S"), pprDemands wrapper_args]
\end{code}
-\begin{code}
-isStrict :: Demand -> Bool
-
-isStrict WwStrict = True
-isStrict (WwUnpack _) = True
-isStrict WwPrim = True
-isStrict WwEnum = True
-isStrict _ = False
-
-nonAbsentArgs :: [Demand] -> Int
-
-nonAbsentArgs cmpts
- = foldr tick_non 0 cmpts
- where
- tick_non (WwLazy True) acc = acc
- tick_non other acc = acc + 1
-
-all_present_WwLazies :: [Demand] -> Bool
-all_present_WwLazies infos
- = and (map is_L infos)
- where
- is_L (WwLazy False) = True -- False <=> "Absent" args do *not* count!
- is_L _ = False -- (as they imply a worker)
-\end{code}
-WDP 95/04: It is no longer enough to look at a list of @Demands@ for
-an ``Unpack'' or an ``Absent'' and declare a worker. We also have to
-check that @mAX_WORKER_ARGS@ hasn't been exceeded. Therefore,
-@indicatesWorker@ mirrors the process used in @mk_ww_arg_processing@
-in \tr{WwLib.lhs}. A worker is ``indicated'' when we hit an Unpack
-or an Absent {\em that we accept}.
\begin{code}
-indicatesWorker :: [Demand] -> Bool
-
-indicatesWorker dems
- = fake_mk_ww (_trace "mAX_WORKER_ARGS" 6 - nonAbsentArgs dems) dems
- where
- fake_mk_ww _ [] = False
- fake_mk_ww _ (WwLazy True : _) = True -- we accepted an Absent
- fake_mk_ww extra_args (WwUnpack cmpnts : dems)
- | extra_args_now > 0 = True -- we accepted an Unpack
- where
- extra_args_now = extra_args + 1 - nonAbsentArgs cmpnts
-
- fake_mk_ww extra_args (_ : dems)
- = fake_mk_ww extra_args dems
-\end{code}
-
-\begin{code}
-mkWrapperArgTypeCategories
- :: Type -- wrapper's type
- -> [Demand] -- info about its arguments
- -> String -- a string saying lots about the args
-
-mkWrapperArgTypeCategories wrapper_ty wrap_info
- = case (splitTypeWithDictsAsArgs wrapper_ty) of { (_,arg_tys,_) ->
- map do_one (wrap_info `zip` (map showTypeCategory arg_tys))
- }
- where
- -- ToDo: this needs FIXING UP (it was a hack anyway...)
- do_one (WwPrim, _) = 'P'
- do_one (WwEnum, _) = 'E'
- do_one (WwStrict, arg_ty_char) = arg_ty_char
- do_one (WwUnpack _, arg_ty_char)
- = if arg_ty_char `elem` "CIJFDTS"
- then toLower arg_ty_char
- else if arg_ty_char == '+' then 't'
- else trace ("mkWrapp..:funny char:"++[arg_ty_char]) '-'
- do_one (other_wrap_info, _) = '-'
-\end{code}
-
-Whether a worker exists depends on whether the worker has an
-absent argument, a @WwUnpack@ argument, (or @WwEnum@ ToDo???) arguments.
-
-If a @WwUnpack@ argument is for an {\em abstract} type (or one that
-will be abstract outside this module), which might happen for an
-imported function, then we can't (or don't want to...) unpack the arg
-as the worker requires. Hence we have to give up altogether, and call
-the wrapper only; so under these circumstances we return \tr{False}.
-
-\begin{code}
-instance Text Demand where
- readList str = read_em [{-acc-}] str
- where
- read_em acc [] = [(reverse acc, "")]
- -- lower case indicates absence...
- read_em acc ('L' : xs) = read_em (WwLazy False : acc) xs
- read_em acc ('A' : xs) = read_em (WwLazy True : acc) xs
- read_em acc ('S' : xs) = read_em (WwStrict : acc) xs
- read_em acc ('P' : xs) = read_em (WwPrim : acc) xs
- read_em acc ('E' : xs) = read_em (WwEnum : acc) xs
-
- read_em acc (')' : xs) = [(reverse acc, xs)]
- read_em acc ( 'U' : '(' : xs)
- = case (read_em [] xs) of
- [(stuff, rest)] -> read_em (WwUnpack stuff : acc) rest
- _ -> panic ("Text.Demand:"++str++"::"++xs)
-
- read_em acc other = panic ("IdInfo.readem:"++other)
-
- showList wrap_args rest = (concat (map show1 wrap_args)) ++ rest
- where
- show1 (WwLazy False) = "L"
- show1 (WwLazy True) = "A"
- show1 WwStrict = "S"
- show1 WwPrim = "P"
- show1 WwEnum = "E"
- show1 (WwUnpack args)= "U(" ++ (concat (map show1 args)) ++ ")"
-
-instance Outputable Demand where
- ppr sty si = ppStr (showList [si] "")
-
-instance OptIdInfo StrictnessInfo where
- noInfo = NoStrictnessInfo
-
- getInfo (IdInfo _ _ _ strict _ _ _ _ _ _) = strict
-
- addInfo id_info NoStrictnessInfo = id_info
- addInfo (IdInfo a b d _ e f g h i j) strict = IdInfo a b d strict e f g h i j
-
- ppInfo sty better_id_fn strictness_info
- = pp_strictness sty Nothing better_id_fn nullIdEnv strictness_info
-\end{code}
-
-We'll omit the worker info if the thing has an explicit unfolding
-already.
-\begin{code}
-pp_strictness sty _ _ _ NoStrictnessInfo = ifPprInterface sty pp_NONE
-
-pp_strictness sty _ _ _ BottomGuaranteed = ppPStr SLIT("_S_ _!_")
-
-pp_strictness sty for_this_id_maybe better_id_fn inline_env
- info@(StrictnessInfo wrapper_args wrkr_maybe)
- = let
- (have_wrkr, wrkr_id) = case wrkr_maybe of
- Nothing -> (False, panic "ppInfo(Strictness)")
- Just xx -> (True, xx)
-
- wrkr_to_print = better_id_fn wrkr_id
- wrkr_info = getIdInfo wrkr_to_print
-
- -- if we aren't going to be able to *read* the strictness info
- -- in TcPragmas, we need not even print it.
- wrapper_args_to_use
- = if not (indicatesWorker wrapper_args) then
- wrapper_args -- no worker/wrappering in any case
- else
- case for_this_id_maybe of
- Nothing -> wrapper_args
- Just id -> if externallyVisibleId id
- && (unfoldingUnfriendlyId id || not have_wrkr) then
- -- pprTrace "IdInfo: unworker-ising:" (ppCat [ppr PprDebug have_wrkr, ppr PprDebug id]) $
- map un_workerise wrapper_args
- else
- wrapper_args
-
- id_is_worker
- = case for_this_id_maybe of
- Nothing -> False
- Just id -> isWorkerId id
-
- am_printing_iface = case sty of { PprInterface -> True ; _ -> False }
-
- pp_basic_info
- = ppBesides [ppStr "_S_ \"",
- ppStr (showList wrapper_args_to_use ""), ppStr "\""]
-
- pp_with_worker
- = ppBesides [ ppSP, ppChar '{',
- ppIdInfo sty wrkr_to_print True{-wrkr specs, yes!-} better_id_fn inline_env wrkr_info,
- ppChar '}' ]
- in
- if all_present_WwLazies wrapper_args_to_use then -- too boring
- ifPprInterface sty pp_NONE
-
- else if id_is_worker && am_printing_iface then
- pp_NONE -- we don't put worker strictness in interfaces
- -- (it can be deduced)
-
- else if not (indicatesWorker wrapper_args_to_use)
- || not have_wrkr
- || boringIdInfo wrkr_info then
- ppBeside pp_basic_info ppNil
- else
- ppBeside pp_basic_info pp_with_worker
- where
- un_workerise (WwLazy _) = WwLazy False -- avoid absence
- un_workerise (WwUnpack _) = WwStrict
- un_workerise other = other
-\end{code}
-
-%************************************************************************
-%* *
-\subsection[unfolding-IdInfo]{Unfolding info about an @Id@}
-%* *
-%************************************************************************
-
-\begin{code}
-mkUnfolding guide expr
- = GenForm False (mkFormSummary NoStrictnessInfo expr)
- (occurAnalyseGlobalExpr expr)
- guide
-\end{code}
-
-\begin{code}
-noInfo_UF = NoUnfoldingDetails
-
-getInfo_UF (IdInfo _ _ _ _ unfolding _ _ _ _ _)
- = case unfolding of
- GenForm _ _ _ BadUnfolding -> NoUnfoldingDetails
- unfolding_as_was -> unfolding_as_was
-
--- getInfo_UF ensures that any BadUnfoldings are never returned
--- We had to delay the test required in TcPragmas until now due
--- to strictness constraints in TcPragmas
-
-addInfo_UF id_info@(IdInfo a b c d e f g h i j) NoUnfoldingDetails = id_info
-addInfo_UF (IdInfo a b d e _ f g h i j) uf = IdInfo a b d e uf f g h i j
+workerExists :: StrictnessInfo -> Bool
+workerExists (StrictnessInfo _ worker_exists) = worker_exists
+workerExists other = False
\end{code}
-\begin{code}
-pp_unfolding sty for_this_id inline_env uf_details
- = case (lookupIdEnv inline_env for_this_id) of
- Nothing -> pp uf_details
- Just dt -> pp dt
- where
- pp NoUnfoldingDetails = pp_NONE
-
- pp (MagicForm tag _)
- = ppCat [ppPStr SLIT("_MF_"), ppPStr tag]
-
- pp (GenForm _ _ _ BadUnfolding) = pp_NONE
-
- pp (GenForm _ _ template guide)
- = let
- untagged = unTagBinders template
- in
- if untagged `isWrapperFor` for_this_id
- then -- pprTrace "IdInfo:isWrapperFor:" (ppAbove (ppr PprDebug for_this_id) (ppr PprDebug untagged))
- pp_NONE
- else ppCat [ppPStr SLIT("_F_"), ppr sty guide, pprCoreUnfolding untagged]
-
-\end{code}
%************************************************************************
%* *
Text instance so that the update annotations can be read in.
\begin{code}
-instance Text UpdateInfo where
- readsPrec p s | null s = panic "IdInfo: empty update pragma?!"
- | otherwise = [(SomeUpdateInfo (map ok_digit s),"")]
- where
- ok_digit c | c >= '0' && c <= '2' = ord c - ord '0'
- | otherwise = panic "IdInfo: not a digit while reading update pragma"
-
-instance OptIdInfo UpdateInfo where
- noInfo = NoUpdateInfo
-
- getInfo (IdInfo _ _ _ _ _ update _ _ _ _) = update
-
- addInfo id_info NoUpdateInfo = id_info
- addInfo (IdInfo a b d e f _ g h i j) upd_info = IdInfo a b d e f upd_info g h i j
-
- ppInfo sty better_id_fn NoUpdateInfo = ifPprInterface sty pp_NONE
- ppInfo sty better_id_fn (SomeUpdateInfo []) = ifPprInterface sty pp_NONE
- ppInfo sty better_id_fn (SomeUpdateInfo spec)
- = ppBeside (ppPStr SLIT("_U_ ")) (ppBesides (map ppInt spec))
-\end{code}
-
-%************************************************************************
-%* *
-\subsection[deforest-IdInfo]{Deforestation info about an @Id@}
-%* *
-%************************************************************************
-
-The deforest info says whether this Id is to be unfolded during
-deforestation. Therefore, when the deforest pragma is true, we must
-also have the unfolding information available for this Id.
-
-\begin{code}
-data DeforestInfo
- = Don'tDeforest -- just a bool, might extend this
- | DoDeforest -- later.
- -- deriving (Eq, Ord)
-\end{code}
-
-\begin{code}
-instance OptIdInfo DeforestInfo where
- noInfo = Don'tDeforest
-
- getInfo (IdInfo _ _ _ _ _ _ deforest _ _ _) = deforest
-
- addInfo id_info Don'tDeforest = id_info
- addInfo (IdInfo a b d e f g _ h i j) deforest =
- IdInfo a b d e f g deforest h i j
-
- ppInfo sty better_id_fn Don'tDeforest
- = ifPprInterface sty pp_NONE
- ppInfo sty better_id_fn DoDeforest
- = ppPStr SLIT("_DEFOREST_")
+ppUpdateInfo NoUpdateInfo = empty
+ppUpdateInfo (SomeUpdateInfo []) = empty
+ppUpdateInfo (SomeUpdateInfo spec) = (<>) (ptext SLIT("__U ")) (hcat (map int spec))
\end{code}
%************************************************************************
%* *
-\subsection[argUsage-IdInfo]{Argument Usage info about an @Id@}
+\subsection[CAF-IdInfo]{CAF-related information}
%* *
%************************************************************************
-\begin{code}
-data ArgUsageInfo
- = NoArgUsageInfo
- | SomeArgUsageInfo ArgUsageType
- -- ??? deriving (Eq, Ord)
-
-data ArgUsage = ArgUsage Int -- number of arguments (is linear!)
- | UnknownArgUsage
-type ArgUsageType = [ArgUsage] -- c_1 -> ... -> BLOB
-\end{code}
+This information is used to build Static Reference Tables (see
+simplStg/ComputeSRT.lhs).
\begin{code}
-mkArgUsageInfo = SomeArgUsageInfo
-
-getArgUsage :: ArgUsageInfo -> ArgUsageType
-getArgUsage NoArgUsageInfo = []
-getArgUsage (SomeArgUsageInfo u) = u
-\end{code}
-
-\begin{code}
-instance OptIdInfo ArgUsageInfo where
- noInfo = NoArgUsageInfo
-
- getInfo (IdInfo _ _ _ _ _ _ _ au _ _) = au
+data CafInfo
+ = MayHaveCafRefs -- either:
+ -- (1) A function or static constructor
+ -- that refers to one or more CAFs,
+ -- (2) A real live CAF
- addInfo id_info NoArgUsageInfo = id_info
- addInfo (IdInfo a b d e f g h _ i j) au_info = IdInfo a b d e f g h au_info i j
+ | NoCafRefs -- A function or static constructor
+ -- that refers to no CAFs.
- ppInfo sty better_id_fn NoArgUsageInfo = ifPprInterface sty pp_NONE
- ppInfo sty better_id_fn (SomeArgUsageInfo []) = ifPprInterface sty pp_NONE
- ppInfo sty better_id_fn (SomeArgUsageInfo aut)
- = ppBeside (ppPStr SLIT("_L_ ")) (ppArgUsageType aut)
+-- LATER: not sure how easy this is...
+-- | OneCafRef Id
-ppArgUsage (ArgUsage n) = ppInt n
-ppArgUsage (UnknownArgUsage) = ppChar '-'
-
-ppArgUsageType aut = ppBesides
- [ ppChar '"' ,
- ppIntersperse ppComma (map ppArgUsage aut),
- ppChar '"' ]
-\end{code}
-%************************************************************************
-%* *
-\subsection[FBType-IdInfo]{Type of an expression through Foldr/build's eyes}
-%* *
-%************************************************************************
-
-\begin{code}
-data FBTypeInfo
- = NoFBTypeInfo
- | SomeFBTypeInfo FBType
- -- ??? deriving (Eq, Ord)
-
-data FBType = FBType [FBConsum] FBProd deriving (Eq)
-
-data FBConsum = FBGoodConsum | FBBadConsum deriving(Eq)
-data FBProd = FBGoodProd | FBBadProd deriving(Eq)
-\end{code}
-
-\begin{code}
-mkFBTypeInfo = SomeFBTypeInfo
-
-getFBType :: FBTypeInfo -> Maybe FBType
-getFBType NoFBTypeInfo = Nothing
-getFBType (SomeFBTypeInfo u) = Just u
-\end{code}
-
-\begin{code}
-instance OptIdInfo FBTypeInfo where
- noInfo = NoFBTypeInfo
-
- getInfo (IdInfo _ _ _ _ _ _ _ _ fb _) = fb
-
- addInfo id_info NoFBTypeInfo = id_info
- addInfo (IdInfo a b d e f g h i _ j) fb_info = IdInfo a b d e f g h i fb_info j
-
- ppInfo PprInterface _ NoFBTypeInfo = ppNil
- ppInfo sty _ NoFBTypeInfo = ifPprInterface sty pp_NONE
- ppInfo sty _ (SomeFBTypeInfo (FBType cons prod))
- = ppBeside (ppPStr SLIT("_F_ ")) (ppFBType cons prod)
-
---ppFBType (FBType n) = ppBesides [ppInt n]
---ppFBType (UnknownFBType) = ppBesides [ppStr "-"]
---
-
-ppFBType cons prod = ppBesides
- ([ ppChar '"' ] ++ map ppCons cons ++ [ ppChar '-', ppProd prod, ppChar '"' ])
- where
- ppCons FBGoodConsum = ppChar 'G'
- ppCons FBBadConsum = ppChar 'B'
- ppProd FBGoodProd = ppChar 'G'
- ppProd FBBadProd = ppChar 'B'
+ppCafInfo NoCafRefs = ptext SLIT("__C")
+ppCafInfo MayHaveCafRefs = empty
\end{code}
projects / ghc-hetmet.git / blobdiff