-
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1995
%
-\section[ClosureInfo]{Data structures which describe closures}
+% (c) The Univserity of Glasgow 1992-2004
+%
+
+ Data structures which describe closures, and
+ operations over those data structures
+
+ Nothing monadic in here
Much of the rationale for these things is in the ``details'' part of
the STG paper.
\begin{code}
-#include "HsVersions.h"
-
module ClosureInfo (
ClosureInfo, LambdaFormInfo, SMRep, -- all abstract
- StandardFormInfo,
+ StandardFormInfo,
- EntryConvention(..),
+ ArgDescr(..), Liveness(..),
+ C_SRT(..), needsSRT,
- mkClosureLFInfo, mkConLFInfo,
- mkLFImported, mkLFArgument, mkLFLetNoEscape,
+ mkLFThunk, mkLFReEntrant, mkConLFInfo, mkSelectorLFInfo,
+ mkApLFInfo, mkLFImported, mkLFArgument, mkLFLetNoEscape,
- closureSize, closureHdrSize,
- closureNonHdrSize, closureSizeWithoutFixedHdr,
- closureGoodStuffSize, closurePtrsSize, -- UNUSED: closureNonPtrsSize,
- slopSize, fitsMinUpdSize,
+ mkClosureInfo, mkConInfo,
- layOutDynClosure, layOutDynCon, layOutStaticClosure,
- layOutStaticNoFVClosure, layOutPhantomClosure,
- mkVirtHeapOffsets, -- for GHCI
+ closureSize, closureNonHdrSize,
+ closureGoodStuffSize, closurePtrsSize,
+ slopSize,
+
+ closureName, infoTableLabelFromCI,
+ closureLabelFromCI, closureSRT,
+ closureLFInfo, closureSMRep, closureUpdReqd,
+ closureSingleEntry, closureReEntrant, isConstrClosure_maybe,
+ closureFunInfo, isStandardFormThunk, isKnownFun,
+
+ enterIdLabel, enterReturnPtLabel,
+
+ nodeMustPointToIt,
+ CallMethod(..), getCallMethod,
- nodeMustPointToIt, getEntryConvention,
blackHoleOnEntry,
- staticClosureRequired,
- slowFunEntryCodeRequired, funInfoTableRequired,
- stdVapRequired, noUpdVapRequired,
+ staticClosureRequired,
+ getClosureType,
- closureId, infoTableLabelFromCI,
- closureLabelFromCI,
- entryLabelFromCI, fastLabelFromCI,
- closureLFInfo, closureSMRep, closureUpdReqd,
- closureSingleEntry, closureSemiTag, closureType,
- closureReturnsUnboxedType, getStandardFormThunkInfo,
-
---OLD auxInfoTableLabelFromCI, isIntLikeRep, -- go away in 0.23
-
- closureKind, closureTypeDescr, -- profiling
-
- isConstantRep, isSpecRep, isPhantomRep, -- ToDo: Should be in SMRep, perhaps?
- isStaticClosure, allocProfilingMsg,
- blackHoleClosureInfo,
- getSMInfoStr, getSMInitHdrStr, getSMUpdInplaceHdrStr,
- ltSMRepHdr, --UNUSED: equivSMRepHdr,
- maybeSelectorInfo,
-
- dataConLiveness, -- concurrency
-
- -- and to make the interface self-sufficient...
- AbstractC, CAddrMode, HeapOffset, MagicId,
- CgInfoDownwards, CgState, CgIdInfo, CompilationInfo,
- CLabel, Id, Maybe, PrimKind, FCode(..), TyCon, StgExpr,
- StgAtom, StgBinderInfo,
- DataCon(..), PlainStgExpr(..), PlainStgLiveVars(..),
- PlainStgAtom(..),
- UniqSet(..), UniqFM, UpdateFlag(..) -- not abstract
-
- IF_ATTACK_PRAGMAS(COMMA mkClosureLabel)
- IF_ATTACK_PRAGMAS(COMMA getUniDataSpecTyCon_maybe)
- ) where
+ isToplevClosure,
+ closureValDescr, closureTypeDescr, -- profiling
-import AbsCSyn
-import CgMonad
-import SMRep
-import StgSyn
+ isStaticClosure,
+ cafBlackHoleClosureInfo, seCafBlackHoleClosureInfo,
-import AbsUniType
-import CgCompInfo -- some magic constants
-import CgRetConv
-import CLabelInfo -- Lots of label-making things
-import CmdLineOpts ( GlobalSwitch(..) )
-import Id
-import IdInfo -- SIGH
-import Maybes ( maybeToBool, assocMaybe, Maybe(..) )
-import Outputable -- needed for INCLUDE_FRC_METHOD
-import Pretty -- ( ppStr, Pretty(..) )
-import PrimKind ( PrimKind, getKindSize, separateByPtrFollowness )
-import Util
-\end{code}
+ staticClosureNeedsLink,
+ ) where
-The ``wrapper'' data type for closure information:
+#include "../includes/MachDeps.h"
+#include "HsVersions.h"
-\begin{code}
-data ClosureInfo
- = MkClosureInfo
- Id -- The thing bound to this closure
- LambdaFormInfo -- info derivable from the *source*
- SMRep -- representation used by storage manager
+import StgSyn
+import SMRep -- all of it
+
+import CLabel
+
+import Constants ( mIN_UPD_SIZE, mIN_SIZE_NonUpdHeapObject )
+import CmdLineOpts ( opt_SccProfilingOn, opt_OmitBlackHoling,
+ opt_Parallel, opt_DoTickyProfiling,
+ opt_SMP )
+import Id ( Id, idType, idArity, idName )
+import DataCon ( DataCon, dataConTyCon, isNullaryDataCon, dataConName )
+import Name ( Name, nameUnique, getOccName, getOccString )
+import OccName ( occNameUserString )
+import Type ( isUnLiftedType, Type, repType, splitTyConApp_maybe )
+import TcType ( tcSplitSigmaTy )
+import TyCon ( isFunTyCon, isAbstractTyCon )
+import BasicTypes ( TopLevelFlag(..), isNotTopLevel, isTopLevel, ipNameName )
+import FastString
+import Outputable
+import Constants
+
+import TypeRep -- TEMP
\end{code}
+
%************************************************************************
%* *
-\subsection[ClosureInfo-OLD-DOC]{OLD DOCUMENTATION PROBABLY SUPERCEDED BY stg-details}
+\subsection[ClosureInfo-datatypes]{Data types for closure information}
%* *
%************************************************************************
-We can optimise the function-entry code as follows.
-\begin{itemize}
-
-\item If the ``function'' is not updatable, we can jump directly to its
- entry code, rather than indirecting via the info pointer in the
- closure. (For updatable thunks we must go via the closure, in
- case it has been updated.)
-
-\item If the former bullet applies, and the application we are
- compiling gives the function as many arguments as it needs, we
- can jump to its fast-entry code. (This only applies if the
- function has one or more args, because zero-arg closures have
- no fast-entry code.)
-
-\item If the function is a top-level non-constructor or imported, there
- is no need to make Node point to its closure. In order for
- this to be right, we need to ensure that:
- \begin{itemize}
- \item If such closures are updatable then they push their
- static address in the update frame, not Node. Actually
- we create a black hole and push its address.
-
- \item The arg satisfaction check should load Node before jumping to
- UpdatePAP.
-
- \item Top-level constructor closures need careful handling. If we are to
- jump direct to the constructor code, we must load Node first, even
- though they are top-level. But if we go to their ``own''
- standard-entry code (which loads Node and then jumps to the
- constructor code) we don't need to load Node.
- \end{itemize}
-\end{itemize}
-
-
-{\em Top level constructors (@mkStaticConEntryInfo@)}
+Information about a closure, from the code generator's point of view.
-\begin{verbatim}
- x = {y,ys} \ {} Cons {y,ys} -- Std form constructor
-\end{verbatim}
+A ClosureInfo decribes the info pointer of a closure. It has
+enough information
+ a) to construct the info table itself
+ b) to allocate a closure containing that info pointer (i.e.
+ it knows the info table label)
-x-closure: Cons-info-table, y-closure, ys-closure
+We make a ClosureInfo for
+ - each let binding (both top level and not)
+ - each data constructor (for its shared static and
+ dynamic info tables)
-x-entry: Node = x-closure; jump( Cons-entry )
-
-x's EntryInfo in its own module:
-\begin{verbatim}
- Base-label = Cons -- Not x!!
- NodeMustPoint = True
- ClosureClass = Constructor
-\end{verbatim}
+\begin{code}
+data ClosureInfo
+ = ClosureInfo {
+ closureName :: !Name, -- The thing bound to this closure
+ closureLFInfo :: !LambdaFormInfo, -- NOTE: not an LFCon (see below)
+ closureSMRep :: !SMRep, -- representation used by storage mgr
+ closureSRT :: !C_SRT, -- What SRT applies to this closure
+ closureType :: !Type, -- Type of closure (ToDo: remove)
+ closureDescr :: !String -- closure description (for profiling)
+ }
+
+ -- Constructor closures don't have a unique info table label (they use
+ -- the constructor's info table), and they don't have an SRT.
+ | ConInfo {
+ closureCon :: !DataCon,
+ closureSMRep :: !SMRep
+ }
+
+-- C_SRT is what StgSyn.SRT gets translated to...
+-- we add a label for the table, and expect only the 'offset/length' form
+
+data C_SRT = NoC_SRT
+ | C_SRT !CLabel !WordOff !StgHalfWord {-bitmap or escape-}
+
+needsSRT :: C_SRT -> Bool
+needsSRT NoC_SRT = False
+needsSRT (C_SRT _ _ _) = True
+\end{code}
- So if x is entered, Node will be set up and
- we'll jump direct to the Cons code.
+%************************************************************************
+%* *
+\subsubsection[LambdaFormInfo-datatype]{@LambdaFormInfo@: source-derivable info}
+%* *
+%************************************************************************
-x's EntryInfo in another module: (which may not know that x is a constructor)
-\begin{verbatim}
- Base-label = x -- Is x!!
- NodeMustPoint = False -- All imported things have False
- ClosureClass = non-committal
-\end{verbatim}
+Information about an identifier, from the code generator's point of
+view. Every identifier is bound to a LambdaFormInfo in the
+environment, which gives the code generator enough info to be able to
+tail call or return that identifier.
- If x is entered, we'll jump to x-entry, which will set up Node
- before jumping to the standard Cons code
+Note that a closure is usually bound to an identifier, so a
+ClosureInfo contains a LambdaFormInfo.
-{\em Top level non-constructors (@mkStaticEntryInfo@)}
-\begin{verbatim}
- x = ...
-\end{verbatim}
+\begin{code}
+data LambdaFormInfo
+ = LFReEntrant -- Reentrant closure (a function)
+ TopLevelFlag -- True if top level
+ !Int -- Arity. Invariant: always > 0
+ !Bool -- True <=> no fvs
+ ArgDescr -- Argument descriptor (should reall be in ClosureInfo)
-For updatable thunks, x-entry must push an allocated BH in update frame, not Node.
+ | LFCon -- A saturated constructor application
+ DataCon -- The constructor
-For non-zero arity, arg satis check must load Node before jumping to
- UpdatePAP.
+ | LFThunk -- Thunk (zero arity)
+ TopLevelFlag
+ !Bool -- True <=> no free vars
+ !Bool -- True <=> updatable (i.e., *not* single-entry)
+ StandardFormInfo
+ !Bool -- True <=> *might* be a function type
-x's EntryInfo in its own module:
-\begin{verbatim}
- Base-label = x
- NodeMustPoint = False
- ClosureClass = whatever
-\end{verbatim}
+ | LFUnknown -- Used for function arguments and imported things.
+ -- We know nothing about this closure. Treat like
+ -- updatable "LFThunk"...
+ -- Imported things which we do know something about use
+ -- one of the other LF constructors (eg LFReEntrant for
+ -- known functions)
+ !Bool -- True <=> *might* be a function type
-{\em Inner constructors (@mkConEntryInfo@)}
+ | LFLetNoEscape -- See LetNoEscape module for precise description of
+ -- these "lets".
+ !Int -- arity;
-\begin{verbatim}
- Base-label = Cons -- Not x!!
- NodeMustPoint = True -- If its arity were zero, it would
- -- have been lifted to top level
- ClosureClass = Constructor
-\end{verbatim}
+ | LFBlackHole -- Used for the closures allocated to hold the result
+ -- of a CAF. We want the target of the update frame to
+ -- be in the heap, so we make a black hole to hold it.
+ CLabel -- Flavour (info label, eg CAF_BLACKHOLE_info).
-{\em Inner non-constructors (@mkEntryInfo@)}
-\begin{verbatim}
- Base-label = x
- NodeMustPoint = True -- If no free vars, would have been
- -- lifted to top level
- ClosureClass = whatever
-\end{verbatim}
+-------------------------
+-- An ArgDsecr describes the argument pattern of a function
-{\em Imported}
+data ArgDescr
+ = ArgSpec -- Fits one of the standard patterns
+ !Int -- RTS type identifier ARG_P, ARG_N, ...
-\begin{verbatim}
- Nothing,
- or
- Base-label = x
- NodeMustPoint = False
- ClosureClass = whatever
-\end{verbatim}
+ | ArgGen -- General case
+ Liveness -- Details about the arguments
-==============
-THINK: we could omit making Node point to top-level constructors
-of arity zero; but that might interact nastily with updates.
-==============
+-------------------------
+-- We represent liveness bitmaps as a Bitmap (whose internal
+-- representation really is a bitmap). These are pinned onto case return
+-- vectors to indicate the state of the stack for the garbage collector.
+--
+-- In the compiled program, liveness bitmaps that fit inside a single
+-- word (StgWord) are stored as a single word, while larger bitmaps are
+-- stored as a pointer to an array of words.
-==========
-The info we need to import for imported things is:
+data Liveness
+ = SmallLiveness -- Liveness info that fits in one word
+ StgWord -- Here's the bitmap
-\begin{verbatim}
- data ImportInfo = UnknownImportInfo
- | HnfImport Int -- Not updatable, arity given
- -- Arity can be zero, for (eg) constrs
- | UpdatableImport -- Must enter via the closure
-\end{verbatim}
+ | BigLiveness -- Liveness info witha a multi-word bitmap
+ CLabel -- Label for the bitmap
-ToDo: move this stuff???
-\begin{pseudocode}
-mkStaticEntryInfo lbl cl_class
- = MkEntryInfo lbl False cl_class
+-------------------------
+-- StandardFormInfo tells whether this thunk has one of
+-- a small number of standard forms
-mkStaticConEntryInfo lbl
- = MkEntryInfo lbl True ConstructorClosure
+data StandardFormInfo
+ = NonStandardThunk
+ -- Not of of the standard forms
-mkEntryInfo lbl cl_class
- = MkEntryInfo lbl True cl_class
+ | SelectorThunk
+ -- A SelectorThunk is of form
+ -- case x of
+ -- con a1,..,an -> ak
+ -- and the constructor is from a single-constr type.
+ WordOff -- 0-origin offset of ak within the "goods" of
+ -- constructor (Recall that the a1,...,an may be laid
+ -- out in the heap in a non-obvious order.)
-mkConEntryInfo lbl
- = MkEntryInfo lbl True ConstructorClosure
-\end{pseudocode}
+ | ApThunk
+ -- An ApThunk is of form
+ -- x1 ... xn
+ -- The code for the thunk just pushes x2..xn on the stack and enters x1.
+ -- There are a few of these (for 1 <= n <= MAX_SPEC_AP_SIZE) pre-compiled
+ -- in the RTS to save space.
+ Int -- Arity, n
+\end{code}
%************************************************************************
%* *
-\subsection[ClosureInfo-datatypes]{Data types for closure information}
+\subsection[ClosureInfo-construction]{Functions which build LFInfos}
%* *
%************************************************************************
-%************************************************************************
-%* *
-\subsubsection[LambdaFormInfo-datatype]{@LambdaFormInfo@: source-derivable info}
-%* *
-%************************************************************************
+\begin{code}
+mkLFReEntrant :: TopLevelFlag -- True of top level
+ -> [Id] -- Free vars
+ -> [Id] -- Args
+ -> ArgDescr -- Argument descriptor
+ -> LambdaFormInfo
+
+mkLFReEntrant top fvs args arg_descr
+ = LFReEntrant top (length args) (null fvs) arg_descr
+
+mkLFThunk thunk_ty top fvs upd_flag
+ = ASSERT( not (isUpdatable upd_flag) || not (isUnLiftedType thunk_ty) )
+ LFThunk top (null fvs)
+ (isUpdatable upd_flag)
+ NonStandardThunk
+ (might_be_a_function thunk_ty)
+
+might_be_a_function :: Type -> Bool
+might_be_a_function ty
+ | Just (tc,_) <- splitTyConApp_maybe (repType ty),
+ not (isFunTyCon tc) && not (isAbstractTyCon tc) = False
+ -- don't forget to check for abstract types, which might
+ -- be functions too.
+ | otherwise = True
+\end{code}
+
+@mkConLFInfo@ is similar, for constructors.
\begin{code}
-data LambdaFormInfo
- = LFReEntrant -- Reentrant closure; used for PAPs too
- Bool -- True if top level
- Int -- Arity
- Bool -- True <=> no fvs
-
- | LFCon -- Constructor
- DataCon -- The constructor (may be specialised)
- Bool -- True <=> zero arity
-
- | LFTuple -- Tuples
- DataCon -- The tuple constructor (may be specialised)
- Bool -- True <=> zero arity
-
- | LFThunk -- Thunk (zero arity)
- Bool -- True <=> top level
- Bool -- True <=> no free vars
- Bool -- True <=> updatable (i.e., *not* single-entry)
- StandardFormInfo
+mkConLFInfo :: DataCon -> LambdaFormInfo
+mkConLFInfo con = LFCon con
- | LFArgument -- Used for function arguments. We know nothing about
- -- this closure. Treat like updatable "LFThunk"...
+mkSelectorLFInfo id offset updatable
+ = LFThunk NotTopLevel False updatable (SelectorThunk offset)
+ (might_be_a_function (idType id))
- | LFImported -- Used for imported things. We know nothing about this
- -- closure. Treat like updatable "LFThunk"...
- -- Imported things which we do know something about use
- -- one of the other LF constructors (eg LFReEntrant for
- -- known functions)
+mkApLFInfo id upd_flag arity
+ = LFThunk NotTopLevel (arity == 0) (isUpdatable upd_flag) (ApThunk arity)
+ (might_be_a_function (idType id))
+\end{code}
- | LFLetNoEscape -- See LetNoEscape module for precise description of
- -- these "lets".
- Int -- arity;
- PlainStgLiveVars-- list of variables live in the RHS of the let.
- -- (ToDo: maybe not used)
+Miscellaneous LF-infos.
- | LFBlackHole -- Used for the closures allocated to hold the result
- -- of a CAF. We want the target of the update frame to
- -- be in the heap, so we make a black hole to hold it.
+\begin{code}
+mkLFArgument id = LFUnknown (might_be_a_function (idType id))
- -- This last one is really only for completeness;
- -- it isn't actually used for anything interesting
- {- | LFIndirection -}
-
-data StandardFormInfo -- Tells whether this thunk has one of a small number
- -- of standard forms
-
- = NonStandardThunk -- No, it isn't
-
- | SelectorThunk
- Id -- Scrutinee
- DataCon -- Constructor
- Int -- 0-origin offset of ak within the "goods" of constructor
- -- (Recall that the a1,...,an may be laid out in the heap
- -- in a non-obvious order.)
-
-{- A SelectorThunk is of form
-
- case x of
- con a1,..,an -> ak
-
- and the constructor is from a single-constr type.
- If we can't convert the heap-offset of the selectee into an Int, e.g.,
- it's "GEN_VHS+i", we just give up.
--}
-
- | VapThunk
- Id -- Function
- [PlainStgAtom] -- Args
- Bool -- True <=> the function is not top-level, so
- -- must be stored in the thunk too
-
-{- A VapThunk is of form
-
- f a1 ... an
-
- where f is a known function, with arity n
- So for this thunk we can use the label for f's heap-entry
- info table (generated when f's defn was dealt with),
- rather than generating a one-off info table and entry code
- for this one thunk.
--}
-
-
-mkLFArgument = LFArgument
-mkLFBlackHole = LFBlackHole
mkLFLetNoEscape = LFLetNoEscape
mkLFImported :: Id -> LambdaFormInfo
mkLFImported id
- = case arityMaybe (getIdArity id) of
- Nothing -> LFImported
- Just 0 -> LFThunk True{-top-lev-} True{-no fvs-}
- True{-updatable-} NonStandardThunk
- Just n -> LFReEntrant True n True -- n > 0
+ = case idArity id of
+ n | n > 0 -> LFReEntrant TopLevel n True (panic "arg_descr") -- n > 0
+ other -> mkLFArgument id -- Not sure of exact arity
\end{code}
%************************************************************************
%* *
-\subsection[ClosureInfo-construction]{Functions which build LFInfos}
+ Building ClosureInfos
%* *
%************************************************************************
-@mkClosureLFInfo@ figures out the appropriate LFInfo for the closure.
-
-\begin{code}
-mkClosureLFInfo :: Bool -- True of top level
- -> [Id] -- Free vars
- -> UpdateFlag -- Update flag
- -> [Id] -- Args
- -> PlainStgExpr -- Body of closure: passed so we
- -- can look for selector thunks!
- -> LambdaFormInfo
-
-mkClosureLFInfo top fvs upd_flag args@(_:_) body -- Non-empty args
- = LFReEntrant top (length args) (null fvs)
-
-mkClosureLFInfo top fvs ReEntrant [] body
- = LFReEntrant top 0 (null fvs)
-\end{code}
-
-OK, this is where we look at the body of the closure to see if it's a
-selector---turgid, but nothing deep. We are looking for a closure of
-{\em exactly} the form:
-\begin{verbatim}
-... = [the_fv] \ u [] ->
- case the_fv of
- con a_1 ... a_n -> a_i
-\end{verbatim}
-Here we go:
\begin{code}
-mkClosureLFInfo False -- don't bother if at top-level
- [the_fv] -- just one...
- Updatable
- [] -- no args (a thunk)
- (StgCase (StgApp (StgVarAtom scrutinee) [{-no args-}] _)
- _ _ _ -- ignore live vars and uniq...
- (StgAlgAlts case_ty
- [(con, params, use_mask,
- (StgApp (StgVarAtom selectee) [{-no args-}] _))]
- StgNoDefault))
- | the_fv == scrutinee -- Scrutinee is the only free variable
- && maybeToBool maybe_offset -- Selectee is a component of the tuple
- && maybeToBool offset_into_int_maybe
- && offset_into_int <= mAX_SPEC_SELECTEE_SIZE -- Offset is small enough
- =
- ASSERT(is_single_constructor) -- This should be true anyway
- LFThunk False False True (SelectorThunk scrutinee con offset_into_int)
+mkClosureInfo :: Bool -- Is static
+ -> Id
+ -> LambdaFormInfo
+ -> Int -> Int -- Total and pointer words
+ -> C_SRT
+ -> String -- String descriptor
+ -> ClosureInfo
+mkClosureInfo is_static id lf_info tot_wds ptr_wds srt_info descr
+ = ClosureInfo { closureName = name,
+ closureLFInfo = lf_info,
+ closureSMRep = sm_rep,
+ closureSRT = srt_info,
+ closureType = idType id,
+ closureDescr = descr }
where
- (_, params_w_offsets) = layOutDynCon con getIdKind params
- maybe_offset = assocMaybe params_w_offsets selectee
- Just the_offset = maybe_offset
- offset_into_int_maybe = intOffsetIntoGoods the_offset
- Just offset_into_int = offset_into_int_maybe
- is_single_constructor = maybeToBool (maybeSingleConstructorTyCon tycon)
- (_,_,_, tycon) = getDataConSig con
-\end{code}
-
-Same kind of thing, looking for vector-apply thunks, of the form:
-
- x = [...] \ .. [] -> f a1 .. an
-
-where f has arity n. We rely on the arity info inside the Id being correct.
-
-\begin{code}
-mkClosureLFInfo top_level
- fvs
- upd_flag
- [] -- No args; a thunk
- (StgApp (StgVarAtom fun_id) args _)
- | not top_level -- A top-level thunk would require a static
- -- vap_info table, which we don't generate just
- -- now; so top-level thunks are never standard
- -- form.
- && isLocallyDefined fun_id -- Must be defined in this module
- && maybeToBool arity_maybe -- A known function with known arity
- && fun_arity > 0 -- It'd better be a function!
- && fun_arity == length args -- Saturated application
- = LFThunk top_level (null fvs) (isUpdatable upd_flag) (VapThunk fun_id args store_fun_in_vap)
+ name = idName id
+ sm_rep = chooseSMRep is_static lf_info tot_wds ptr_wds
+
+mkConInfo :: Bool -- Is static
+ -> DataCon
+ -> Int -> Int -- Total and pointer words
+ -> ClosureInfo
+mkConInfo is_static data_con tot_wds ptr_wds
+ = ConInfo { closureSMRep = sm_rep,
+ closureCon = data_con }
where
- arity_maybe = arityMaybe (getIdArity fun_id)
- Just fun_arity = arity_maybe
-
- -- If the function is a free variable then it must be stored
- -- in the thunk too; if it isn't a free variable it must be
- -- because it's constant, so it doesn't need to be stored in the thunk
- store_fun_in_vap = fun_id `is_elem` fvs
-
- is_elem = isIn "mkClosureLFInfo"
-\end{code}
-
-Finally, the general updatable-thing case:
-\begin{code}
-mkClosureLFInfo top fvs upd_flag [] body
- = LFThunk top (null fvs) (isUpdatable upd_flag) NonStandardThunk
-
-isUpdatable ReEntrant = False
-isUpdatable SingleEntry = False
-isUpdatable Updatable = True
+ sm_rep = chooseSMRep is_static (mkConLFInfo data_con) tot_wds ptr_wds
\end{code}
-@mkConLFInfo@ is similar, for constructors.
-
-\begin{code}
-mkConLFInfo :: DataCon -> LambdaFormInfo
-
-mkConLFInfo con
- = ASSERT(isDataCon con)
- let
- arity = getDataConArity con
- in
- if isTupleCon con then
- LFTuple con (arity == 0)
- else
- LFCon con (arity == 0)
-\end{code}
-
-
%************************************************************************
%* *
\subsection[ClosureInfo-sizes]{Functions about closure {\em sizes}}
%************************************************************************
\begin{code}
-closureSize :: ClosureInfo -> HeapOffset
-closureSize cl_info@(MkClosureInfo _ _ sm_rep)
- = totHdrSize sm_rep `addOff` (intOff (closureNonHdrSize cl_info))
-
-closureSizeWithoutFixedHdr :: ClosureInfo -> HeapOffset
-closureSizeWithoutFixedHdr cl_info@(MkClosureInfo _ _ sm_rep)
- = varHdrSize sm_rep `addOff` (intOff (closureNonHdrSize cl_info))
-
-closureHdrSize :: ClosureInfo -> HeapOffset
-closureHdrSize (MkClosureInfo _ _ sm_rep)
- = totHdrSize sm_rep
-
-closureNonHdrSize :: ClosureInfo -> Int
-closureNonHdrSize cl_info@(MkClosureInfo _ lf_info sm_rep)
- = tot_wds + computeSlopSize tot_wds sm_rep (closureUpdReqd cl_info) --ToDo: pass lf_info?
+closureSize :: ClosureInfo -> WordOff
+closureSize cl_info = fixedHdrSize + closureNonHdrSize cl_info
+
+closureNonHdrSize :: ClosureInfo -> WordOff
+closureNonHdrSize cl_info
+ = tot_wds + computeSlopSize tot_wds
+ (closureSMRep cl_info)
+ (closureNeedsUpdSpace cl_info)
where
tot_wds = closureGoodStuffSize cl_info
-closureGoodStuffSize :: ClosureInfo -> Int
-closureGoodStuffSize (MkClosureInfo _ _ sm_rep)
- = let (ptrs, nonptrs) = sizes_from_SMRep sm_rep
+-- we leave space for an update if either (a) the closure is updatable
+-- or (b) it is a static thunk. This is because a static thunk needs
+-- a static link field in a predictable place (after the slop), regardless
+-- of whether it is updatable or not.
+closureNeedsUpdSpace (ClosureInfo { closureLFInfo =
+ LFThunk TopLevel _ _ _ _ }) = True
+closureNeedsUpdSpace cl_info = closureUpdReqd cl_info
+
+slopSize :: ClosureInfo -> WordOff
+slopSize cl_info
+ = computeSlopSize (closureGoodStuffSize cl_info)
+ (closureSMRep cl_info)
+ (closureNeedsUpdSpace cl_info)
+
+closureGoodStuffSize :: ClosureInfo -> WordOff
+closureGoodStuffSize cl_info
+ = let (ptrs, nonptrs) = sizes_from_SMRep (closureSMRep cl_info)
in ptrs + nonptrs
-closurePtrsSize :: ClosureInfo -> Int
-closurePtrsSize (MkClosureInfo _ _ sm_rep)
- = let (ptrs, _) = sizes_from_SMRep sm_rep
+closurePtrsSize :: ClosureInfo -> WordOff
+closurePtrsSize cl_info
+ = let (ptrs, _) = sizes_from_SMRep (closureSMRep cl_info)
in ptrs
-- not exported:
-sizes_from_SMRep (SpecialisedRep k ptrs nonptrs _) = (ptrs, nonptrs)
-sizes_from_SMRep (GenericRep ptrs nonptrs _) = (ptrs, nonptrs)
-sizes_from_SMRep (BigTupleRep ptrs) = (ptrs, 0)
-sizes_from_SMRep (MuTupleRep ptrs) = (ptrs, 0)
-sizes_from_SMRep (DataRep nonptrs) = (0, nonptrs)
-sizes_from_SMRep BlackHoleRep = (0, 0)
-sizes_from_SMRep (StaticRep ptrs nonptrs) = (ptrs, nonptrs)
-#ifdef DEBUG
-sizes_from_SMRep PhantomRep = panic "sizes_from_SMRep: PhantomRep"
-sizes_from_SMRep DynamicRep = panic "sizes_from_SMRep: DynamicRep"
-#endif
-\end{code}
-
-\begin{code}
-fitsMinUpdSize :: ClosureInfo -> Bool
-fitsMinUpdSize (MkClosureInfo _ _ BlackHoleRep) = True
-fitsMinUpdSize cl_info = isSpecRep (closureSMRep cl_info) && closureNonHdrSize cl_info <= mIN_UPD_SIZE
+sizes_from_SMRep :: SMRep -> (WordOff,WordOff)
+sizes_from_SMRep (GenericRep _ ptrs nonptrs _) = (ptrs, nonptrs)
+sizes_from_SMRep BlackHoleRep = (0, 0)
\end{code}
Computing slop size. WARNING: this looks dodgy --- it has deep
Updateable closures must be @mIN_UPD_SIZE@.
\begin{itemize}
\item
- Cons cell requires 2 words
- \item
Indirections require 1 word
\item
Appels collector indirections 2 words
Copying collector forward pointer requires 1 word
THEREFORE: @mIN_SIZE_NonUpdHeapObject = 1@
-
-\item
-@SpecialisedRep@ closures closures may require slop:
- \begin{itemize}
- \item
- @ConstantRep@ and @CharLikeRep@ closures always use the address of
- a static closure. They are never allocated or
- collected (eg hold forwarding pointer) hence never any slop.
-
- \item
- @IntLikeRep@ are never updatable.
- May need slop to be collected (as they will be size 1 or more
- this probably has no affect)
-
- \item
- @SpecRep@ may be updateable and will be collectable
-
- \item
- @StaticRep@ may require slop if updatable. Non-updatable ones are OK.
-
- \item
- @GenericRep@ closures will always be larger so never require slop.
- \end{itemize}
-
- ***** ToDo: keep an eye on this!
\end{itemize}
-\begin{code}
-slopSize cl_info@(MkClosureInfo _ lf_info sm_rep)
- = computeSlopSize (closureGoodStuffSize cl_info) sm_rep (closureUpdReqd cl_info)
-
-computeSlopSize :: Int -> SMRep -> Bool -> Int
+Static closures have an extra ``static link field'' at the end, but we
+don't bother taking that into account here.
-computeSlopSize tot_wds (SpecialisedRep ConstantRep _ _ _) _
- = 0
-computeSlopSize tot_wds (SpecialisedRep CharLikeRep _ _ _) _
- = 0
+\begin{code}
+computeSlopSize :: WordOff -> SMRep -> Bool -> WordOff
-computeSlopSize tot_wds (SpecialisedRep _ _ _ _) True -- Updatable
+computeSlopSize tot_wds (GenericRep _ _ _ _) True -- Updatable
= max 0 (mIN_UPD_SIZE - tot_wds)
-computeSlopSize tot_wds (StaticRep _ _) True -- Updatable
- = max 0 (mIN_UPD_SIZE - tot_wds)
-computeSlopSize tot_wds BlackHoleRep _ -- Updatable
- = max 0 (mIN_UPD_SIZE - tot_wds)
-
-computeSlopSize tot_wds (SpecialisedRep _ _ _ _) False -- Not updatable
- = max 0 (mIN_SIZE_NonUpdHeapObject - tot_wds)
-computeSlopSize tot_wds other_rep _ -- Any other rep
- = 0
-\end{code}
-
-%************************************************************************
-%* *
-\subsection[layOutDynClosure]{Lay out a dynamic closure}
-%* *
-%************************************************************************
+computeSlopSize tot_wds (GenericRep True _ _ _) False -- Non updatable
+ = 0 -- Static
-\begin{code}
-layOutDynClosure, layOutStaticClosure
- :: Id -- STG identifier w/ which this closure assoc'd
- -> (a -> PrimKind) -- function w/ which to be able to get a PrimKind
- -> [a] -- the "things" being layed out
- -> LambdaFormInfo -- what sort of closure it is
- -> (ClosureInfo, -- info about the closure
- [(a, VirtualHeapOffset)]) -- things w/ offsets pinned on them
-
-layOutDynClosure name kind_fn things lf_info
- = (MkClosureInfo name lf_info sm_rep,
- things_w_offsets)
- where
- (tot_wds, -- #ptr_wds + #nonptr_wds
- ptr_wds, -- #ptr_wds
- things_w_offsets) = mkVirtHeapOffsets sm_rep kind_fn things
- sm_rep = chooseDynSMRep lf_info tot_wds ptr_wds
-
-layOutStaticClosure name kind_fn things lf_info
- = (MkClosureInfo name lf_info (StaticRep ptr_wds (tot_wds - ptr_wds)),
- things_w_offsets)
- where
- (tot_wds, -- #ptr_wds + #nonptr_wds
- ptr_wds, -- #ptr_wds
- things_w_offsets) = mkVirtHeapOffsets (StaticRep bot bot) kind_fn things
- bot = panic "layoutStaticClosure"
-
-layOutStaticNoFVClosure :: Id -> LambdaFormInfo -> ClosureInfo
-layOutStaticNoFVClosure name lf_info
- = MkClosureInfo name lf_info (StaticRep ptr_wds nonptr_wds)
- where
- -- I am very uncertain that this is right - it will show up when testing
- -- my dynamic loading code. ADR
- -- (If it's not right, we'll have to grab the kinds of the arguments from
- -- somewhere.)
- ptr_wds = 0
- nonptr_wds = 0
-
-layOutPhantomClosure :: Id -> LambdaFormInfo -> ClosureInfo
-layOutPhantomClosure name lf_info = MkClosureInfo name lf_info PhantomRep
-\end{code}
+computeSlopSize tot_wds (GenericRep False _ _ _) False -- Non updatable
+ = max 0 (mIN_SIZE_NonUpdHeapObject - tot_wds) -- Dynamic
-A wrapper for when used with data constructors:
-\begin{code}
-layOutDynCon :: DataCon
- -> (a -> PrimKind)
- -> [a]
- -> (ClosureInfo, [(a,VirtualHeapOffset)])
-
-layOutDynCon con kind_fn args
- = ASSERT(isDataCon con)
- layOutDynClosure con kind_fn args (mkConLFInfo con)
+computeSlopSize tot_wds BlackHoleRep _ -- Updatable
+ = max 0 (mIN_UPD_SIZE - tot_wds)
\end{code}
-
%************************************************************************
%* *
\subsection[SMreps]{Choosing SM reps}
%************************************************************************
\begin{code}
-chooseDynSMRep
- :: LambdaFormInfo
- -> Int -> Int -- Tot wds, ptr wds
+chooseSMRep
+ :: Bool -- True <=> static closure
+ -> LambdaFormInfo
+ -> WordOff -> WordOff -- Tot wds, ptr wds
-> SMRep
-chooseDynSMRep lf_info tot_wds ptr_wds
+chooseSMRep is_static lf_info tot_wds ptr_wds
= let
- nonptr_wds = tot_wds - ptr_wds
-
- updatekind = case lf_info of
- LFThunk _ _ upd _ -> if upd then SMUpdatable else SMSingleEntry
- LFBlackHole -> SMUpdatable
- _ -> SMNormalForm
+ nonptr_wds = tot_wds - ptr_wds
+ closure_type = getClosureType is_static ptr_wds lf_info
in
- if (nonptr_wds == 0 && ptr_wds <= mAX_SPEC_ALL_PTRS)
- || (tot_wds <= mAX_SPEC_MIXED_FIELDS)
- || (ptr_wds == 0 && nonptr_wds <= mAX_SPEC_ALL_NONPTRS) then
- let
- spec_kind = case lf_info of
-
- (LFTuple _ True) -> ConstantRep
-
- (LFTuple _ _) -> SpecRep
+ GenericRep is_static ptr_wds nonptr_wds closure_type
- (LFCon _ True) -> ConstantRep
+-- We *do* get non-updatable top-level thunks sometimes. eg. f = g
+-- gets compiled to a jump to g (if g has non-zero arity), instead of
+-- messing around with update frames and PAPs. We set the closure type
+-- to FUN_STATIC in this case.
- (LFCon con _ ) -> if maybeToBool (maybeCharLikeTyCon tycon) then CharLikeRep
- else if maybeToBool (maybeIntLikeTyCon tycon) then IntLikeRep
- else SpecRep
- where
- tycon = getDataConTyCon con
-
- _ -> SpecRep
- in
- SpecialisedRep spec_kind ptr_wds nonptr_wds updatekind
- else
- GenericRep ptr_wds nonptr_wds updatekind
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection[mkVirtHeapOffsets]{Assigning heap offsets in a closure}
-%* *
-%************************************************************************
-
-@mkVirtHeapOffsets@ (the heap version) always returns boxed things with
-smaller offsets than the unboxed things, and furthermore, the offsets in
-the result list
-
-\begin{code}
-mkVirtHeapOffsets :: SMRep -- Representation to be used by storage manager
- -> (a -> PrimKind) -- To be able to grab kinds;
- -- w/ a kind, we can find boxedness
- -> [a] -- Things to make offsets for
- -> (Int, -- *Total* number of words allocated
- Int, -- Number of words allocated for *pointers*
- [(a, VirtualHeapOffset)]) -- Things with their offsets from start of object
- -- in order of increasing offset
-
--- First in list gets lowest offset, which is initial offset + 1.
-
-mkVirtHeapOffsets sm_rep kind_fun things
- = let (ptrs, non_ptrs) = separateByPtrFollowness kind_fun things
- (wds_of_ptrs, ptrs_w_offsets) = mapAccumL computeOffset 0 ptrs
- (tot_wds, non_ptrs_w_offsets) = mapAccumL computeOffset wds_of_ptrs non_ptrs
- in
- (tot_wds, wds_of_ptrs, ptrs_w_offsets ++ non_ptrs_w_offsets)
- where
- offset_of_first_word = totHdrSize sm_rep
- computeOffset wds_so_far thing
- = (wds_so_far + (getKindSize . kind_fun) thing,
- (thing, (offset_of_first_word `addOff` (intOff wds_so_far)))
- )
+getClosureType :: Bool -> WordOff -> LambdaFormInfo -> ClosureType
+getClosureType is_static ptr_wds lf_info
+ = case lf_info of
+ LFCon con | is_static && ptr_wds == 0 -> ConstrNoCaf
+ | otherwise -> Constr
+ LFReEntrant _ _ _ _ -> Fun
+ LFThunk _ _ _ (SelectorThunk _) _ -> ThunkSelector
+ LFThunk _ _ _ _ _ -> Thunk
+ _ -> panic "getClosureType"
\end{code}
%************************************************************************
Be sure to see the stg-details notes about these...
\begin{code}
-nodeMustPointToIt :: LambdaFormInfo -> FCode Bool
-nodeMustPointToIt lf_info
- = isSwitchSetC SccProfilingOn `thenFC` \ do_profiling ->
-
- case lf_info of
- LFReEntrant top arity no_fvs -> returnFC (
- not no_fvs || -- Certainly if it has fvs we need to point to it
-
- not top -- If it is not top level we will point to it
+nodeMustPointToIt :: LambdaFormInfo -> Bool
+nodeMustPointToIt (LFReEntrant top _ no_fvs _)
+ = not no_fvs || -- Certainly if it has fvs we need to point to it
+ isNotTopLevel top
+ -- If it is not top level we will point to it
-- We can have a \r closure with no_fvs which
-- is not top level as special case cgRhsClosure
-- has been dissabled in favour of let floating
---OLD: || (arity == 0 && do_profiling)
--- -- Access to cost centre required for 0 arity if profiling
--- -- Simon: WHY? (94/12)
-
-- For lex_profiling we also access the cost centre for a
-- non-inherited function i.e. not top level
-- the not top case above ensures this is ok.
- )
- LFCon _ zero_arity -> returnFC True
- LFTuple _ zero_arity -> returnFC True
+nodeMustPointToIt (LFCon _) = True
-- Strictly speaking, the above two don't need Node to point
-- to it if the arity = 0. But this is a *really* unlikely
-- having Node point to the result of an update. SLPJ
-- 27/11/92.
- LFThunk _ no_fvs updatable _
- -> returnFC (updatable || not no_fvs || do_profiling)
-
+nodeMustPointToIt (LFThunk _ no_fvs updatable NonStandardThunk _)
+ = updatable || not no_fvs || opt_SccProfilingOn
-- For the non-updatable (single-entry case):
--
-- True if has fvs (in which case we need access to them, and we
-- or profiling (in which case we need to recover the cost centre
-- from inside it)
- LFArgument -> returnFC True
- LFImported -> returnFC True
- LFBlackHole -> returnFC True
- -- BH entry may require Node to point
+nodeMustPointToIt (LFThunk _ no_fvs updatable some_standard_form_thunk _)
+ = True -- Node must point to any standard-form thunk
- LFLetNoEscape _ _ -> returnFC False
+nodeMustPointToIt (LFUnknown _) = True
+nodeMustPointToIt (LFBlackHole _) = True -- BH entry may require Node to point
+nodeMustPointToIt (LFLetNoEscape _) = False
\end{code}
The entry conventions depend on the type of closure being entered,
0 arg, fvs @\u@ & yes & yes & n/a & node\\
\end{tabular}
-When black-holing, single-entry closures could also be entered via node
+When black-holing, single-entry closures could also be entered via node
(rather than directly) to catch double-entry.
\begin{code}
-data EntryConvention
- = ViaNode -- The "normal" convention
+data CallMethod
+ = EnterIt -- no args, not a function
+
+ | JumpToIt CLabel -- no args, not a function, but we
+ -- know what its entry code is
- | StdEntry CLabel -- Jump to this code, with args on stack
- (Maybe CLabel) -- possibly setting infoptr to this
+ | ReturnIt -- it's a function, but we have
+ -- zero args to apply to it, so just
+ -- return it.
- | DirectEntry -- Jump directly to code, with args in regs
+ | ReturnCon DataCon -- It's a data constructor, just return it
+
+ | SlowCall -- Unknown fun, or known fun with
+ -- too few args.
+
+ | DirectEntry -- Jump directly, with args in regs
CLabel -- The code label
Int -- Its arity
- [MagicId] -- Its register assignments (possibly empty)
-
-getEntryConvention :: Id -- Function being applied
- -> LambdaFormInfo -- Its info
- -> [PrimKind] -- Available arguments
- -> FCode EntryConvention
-
-getEntryConvention id lf_info arg_kinds
- = nodeMustPointToIt lf_info `thenFC` \ node_points ->
- isSwitchSetC ForConcurrent `thenFC` \ is_concurrent ->
- getIntSwitchChkrC `thenFC` \ isw_chkr ->
- returnFC (
-
- if (node_points && is_concurrent) then ViaNode else
-
- case lf_info of
-
- LFReEntrant _ arity _ ->
- if arity == 0 || (length arg_kinds) < arity then
- StdEntry (mkStdEntryLabel id) Nothing
- else
- DirectEntry (mkFastEntryLabel id arity) arity arg_regs
- where
- (arg_regs, _) = assignRegs isw_chkr live_regs (take arity arg_kinds)
- live_regs = if node_points then [node] else []
-
- LFCon con zero_arity
- -> let itbl = if zero_arity then
- mkPhantomInfoTableLabel con
- else
- mkInfoTableLabel con
- in StdEntry (mkStdEntryLabel con) (Just itbl)
- -- Should have no args
- LFTuple tup zero_arity
- -> StdEntry (mkStdEntryLabel tup)
- (Just (mkInfoTableLabel tup))
- -- Should have no args
-
- LFThunk _ _ updatable std_form_info
- -> if updatable
- then ViaNode
- else StdEntry (thunkEntryLabel id std_form_info updatable) Nothing
-
- LFArgument -> ViaNode
- LFImported -> ViaNode
- LFBlackHole -> ViaNode -- Presumably the black hole has by now
- -- been updated, but we don't know with
- -- what, so we enter via Node
-
- LFLetNoEscape arity _
- -> ASSERT(arity == length arg_kinds)
- DirectEntry (mkStdEntryLabel id) arity arg_regs
- where
- (arg_regs, _) = assignRegs isw_chkr live_regs arg_kinds
- live_regs = if node_points then [node] else []
- )
-
-blackHoleOnEntry :: Bool -- No-black-holing flag
- -> ClosureInfo
- -> Bool
+getCallMethod :: Name -- Function being applied
+ -> LambdaFormInfo -- Its info
+ -> Int -- Number of available arguments
+ -> CallMethod
+
+getCallMethod name lf_info n_args
+ | nodeMustPointToIt lf_info && opt_Parallel
+ = -- If we're parallel, then we must always enter via node.
+ -- The reason is that the closure may have been
+ -- fetched since we allocated it.
+ EnterIt
+
+getCallMethod name (LFReEntrant _ arity _ _) n_args
+ | n_args == 0 = ASSERT( arity /= 0 )
+ ReturnIt -- No args at all
+ | n_args < arity = SlowCall -- Not enough args
+ | otherwise = DirectEntry (enterIdLabel name) arity
+
+getCallMethod name (LFCon con) n_args
+ = ASSERT( n_args == 0 )
+ ReturnCon con
+
+getCallMethod name (LFThunk _ _ updatable std_form_info is_fun) n_args
+ | is_fun -- Must always "call" a function-typed
+ = SlowCall -- thing, cannot just enter it [in eval/apply, the entry code
+ -- is the fast-entry code]
+
+ | updatable || opt_DoTickyProfiling -- to catch double entry
+ || opt_SMP -- Always enter via node on SMP, since the
+ -- thunk might have been blackholed in the
+ -- meantime.
+ = ASSERT( n_args == 0 ) EnterIt
+
+ | otherwise -- Jump direct to code for single-entry thunks
+ = ASSERT( n_args == 0 )
+ JumpToIt (thunkEntryLabel name std_form_info updatable)
+
+getCallMethod name (LFUnknown True) n_args
+ = SlowCall -- might be a function
+
+getCallMethod name (LFUnknown False) n_args
+ = ASSERT2 ( n_args == 0, ppr name <+> ppr n_args )
+ EnterIt -- Not a function
+
+getCallMethod name (LFBlackHole _) n_args
+ = SlowCall -- Presumably the black hole has by now
+ -- been updated, but we don't know with
+ -- what, so we slow call it
+
+getCallMethod name (LFLetNoEscape 0) n_args
+ = JumpToIt (enterReturnPtLabel (nameUnique name))
+
+getCallMethod name (LFLetNoEscape arity) n_args
+ | n_args == arity = DirectEntry (enterReturnPtLabel (nameUnique name)) arity
+ | otherwise = pprPanic "let-no-escape: " (ppr name <+> ppr arity)
+
+blackHoleOnEntry :: ClosureInfo -> Bool
-- Static closures are never themselves black-holed.
--- Updatable ones will be overwritten with a CAFList cell, which points to a black hole;
--- Single-entry ones have no fvs to plug, and we trust they don't form part of a loop.
+-- Updatable ones will be overwritten with a CAFList cell, which points to a
+-- black hole;
+-- Single-entry ones have no fvs to plug, and we trust they don't form part
+-- of a loop.
-blackHoleOnEntry no_black_holing (MkClosureInfo _ _ (StaticRep _ _)) = False
+blackHoleOnEntry ConInfo{} = False
+blackHoleOnEntry (ClosureInfo { closureLFInfo = lf_info, closureSMRep = rep })
+ | isStaticRep rep
+ = False -- Never black-hole a static closure
-blackHoleOnEntry no_black_holing (MkClosureInfo _ lf_info _)
+ | otherwise
= case lf_info of
- LFReEntrant _ _ _ -> False
- LFThunk _ no_fvs updatable _
+ LFReEntrant _ _ _ _ -> False
+ LFLetNoEscape _ -> False
+ LFThunk _ no_fvs updatable _ _
-> if updatable
- then not no_black_holing
- else not no_fvs
- other -> panic "blackHoleOnEntry" -- Should never happen
-
-getStandardFormThunkInfo
- :: LambdaFormInfo
- -> Maybe [PlainStgAtom] -- Nothing => not a standard-form thunk
- -- Just atoms => a standard-form thunk with payload atoms
-
-getStandardFormThunkInfo (LFThunk _ _ _ (SelectorThunk scrutinee _ _))
- = --trace "Selector thunk: missed opportunity to save info table + code"
- Nothing
- -- Just [StgVarAtom scrutinee]
- -- We can't save the info tbl + code until we have a way to generate
- -- a fixed family thereof.
-
-getStandardFormThunkInfo (LFThunk _ _ _ (VapThunk fun_id args fun_in_payload))
- | fun_in_payload = Just (StgVarAtom fun_id : args)
- | otherwise = Just args
-
-getStandardFormThunkInfo other_lf_info = Nothing
-
-maybeSelectorInfo (MkClosureInfo _ (LFThunk _ _ _ (SelectorThunk _ con offset)) _) = Just (con,offset)
-maybeSelectorInfo _ = Nothing
+ then not opt_OmitBlackHoling
+ else opt_DoTickyProfiling || not no_fvs
+ -- the former to catch double entry,
+ -- and the latter to plug space-leaks. KSW/SDM 1999-04.
+
+ other -> panic "blackHoleOnEntry" -- Should never happen
+
+isStandardFormThunk :: LambdaFormInfo -> Bool
+isStandardFormThunk (LFThunk _ _ _ (SelectorThunk _) _) = True
+isStandardFormThunk (LFThunk _ _ _ (ApThunk _) _) = True
+isStandardFormThunk other_lf_info = False
+
+isKnownFun :: LambdaFormInfo -> Bool
+isKnownFun (LFReEntrant _ _ _ _) = True
+isKnownFun (LFLetNoEscape _) = True
+isKnownFun _ = False
+\end{code}
+
+-----------------------------------------------------------------------------
+SRT-related stuff
+
+\begin{code}
+staticClosureNeedsLink :: ClosureInfo -> Bool
+-- A static closure needs a link field to aid the GC when traversing
+-- the static closure graph. But it only needs such a field if either
+-- a) it has an SRT
+-- b) it's a constructor with one or more pointer fields
+-- In case (b), the constructor's fields themselves play the role
+-- of the SRT.
+staticClosureNeedsLink (ClosureInfo { closureSRT = srt })
+ = needsSRT srt
+staticClosureNeedsLink (ConInfo { closureSMRep = sm_rep, closureCon = con })
+ = not (isNullaryDataCon con) && not_nocaf_constr
+ where
+ not_nocaf_constr =
+ case sm_rep of
+ GenericRep _ _ _ ConstrNoCaf -> False
+ _other -> True
\end{code}
Avoiding generating entries and info tables
OR (b) the function is passed as an arg
OR (c) if the function has free vars (ie not top level)
- Why case (a) here? Because if the arg-satis check fails,
+ Why case (a) here? Because if the arg-satis check fails,
UpdatePAP stuffs a pointer to the function closure in the PAP.
[Could be changed; UpdatePAP could stuff in a code ptr instead,
but doesn't seem worth it.]
- [NB: these conditions imply that we might need the closure
+ [NB: these conditions imply that we might need the closure
without the slow-entry code. Here's how.
f x y = let g w = ...x..y..w...
Needed iff (a) we have any un-saturated calls to the function
OR (b) the function is passed as an arg
OR (c) the function has free vars (ie not top level)
-
+
NB. In the sequential world, (c) is only required so that the function closure has
an info table to point to, to keep the storage manager happy.
If (c) alone is true we could fake up an info table by choosing
to use an error label in the info table to substitute for the absent
slow entry code.
-* Standard vap-entry code
- Standard vap-entry info table
- Needed iff we have any updatable thunks of the standard vap-entry shape.
-
-* Single-update vap-entry code
- Single-update vap-entry info table
- Needed iff we have any non-updatable thunks of the
- standard vap-entry shape.
-
-
\begin{code}
staticClosureRequired
- :: Id
- -> StgBinderInfo
- -> LambdaFormInfo
- -> Bool
-staticClosureRequired binder (StgBinderInfo arg_occ unsat_occ _ _ _)
- (LFReEntrant top_level _ _) -- It's a function
- = ASSERT( top_level ) -- Assumption: it's a top-level, no-free-var binding
- arg_occ -- There's an argument occurrence
- || unsat_occ -- There's an unsaturated call
- || externallyVisibleId binder
-
-staticClosureRequired binder other_binder_info other_lf_info = True
-
-slowFunEntryCodeRequired -- Assumption: it's a function, not a thunk.
- :: Id
- -> StgBinderInfo
- -> Bool
-slowFunEntryCodeRequired binder (StgBinderInfo arg_occ unsat_occ _ _ _)
- = arg_occ -- There's an argument occurrence
- || unsat_occ -- There's an unsaturated call
- || externallyVisibleId binder
- {- HAS FREE VARS AND IS PARALLEL WORLD -}
-
-slowFunEntryCodeRequired binder NoStgBinderInfo = True
-
-funInfoTableRequired
- :: Id
+ :: Name
-> StgBinderInfo
-> LambdaFormInfo
-> Bool
-funInfoTableRequired binder (StgBinderInfo arg_occ unsat_occ _ _ _)
- (LFReEntrant top_level _ _)
- = not top_level
- || arg_occ -- There's an argument occurrence
- || unsat_occ -- There's an unsaturated call
- || externallyVisibleId binder
-
-funInfoTableRequired other_binder_info binder other_lf_info = True
-
--- We need the vector-apply entry points for a function if
--- there's a vector-apply occurrence in this module
+staticClosureRequired binder bndr_info
+ (LFReEntrant top_level _ _ _) -- It's a function
+ = ASSERT( isTopLevel top_level )
+ -- Assumption: it's a top-level, no-free-var binding
+ not (satCallsOnly bndr_info)
-stdVapRequired, noUpdVapRequired :: StgBinderInfo -> Bool
-
-stdVapRequired binder_info
- = case binder_info of
- StgBinderInfo _ _ std_vap_occ _ _ -> std_vap_occ
- _ -> False
-
-noUpdVapRequired binder_info
- = case binder_info of
- StgBinderInfo _ _ _ no_upd_vap_occ _ -> no_upd_vap_occ
- _ -> False
+staticClosureRequired binder other_binder_info other_lf_info = True
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-isConstantRep, isSpecRep, isStaticRep, isPhantomRep, isIntLikeRep :: SMRep -> Bool
-isConstantRep (SpecialisedRep ConstantRep _ _ _) = True
-isConstantRep other = False
-
-isSpecRep (SpecialisedRep kind _ _ _) = True -- All the kinds of Spec closures
-isSpecRep other = False -- True indicates that the _VHS is 0 !
-
-isStaticRep (StaticRep _ _) = True
-isStaticRep _ = False
-
-isPhantomRep PhantomRep = True
-isPhantomRep _ = False
-
-isIntLikeRep (SpecialisedRep IntLikeRep _ _ _) = True
-isIntLikeRep other = False
isStaticClosure :: ClosureInfo -> Bool
-isStaticClosure (MkClosureInfo _ _ rep) = isStaticRep rep
-
-closureId :: ClosureInfo -> Id
-closureId (MkClosureInfo id _ _) = id
-
-closureSMRep :: ClosureInfo -> SMRep
-closureSMRep (MkClosureInfo _ _ sm_rep) = sm_rep
-
-closureLFInfo :: ClosureInfo -> LambdaFormInfo
-closureLFInfo (MkClosureInfo _ lf_info _) = lf_info
+isStaticClosure cl_info = isStaticRep (closureSMRep cl_info)
closureUpdReqd :: ClosureInfo -> Bool
-
-closureUpdReqd (MkClosureInfo _ (LFThunk _ _ upd _) _) = upd
-closureUpdReqd (MkClosureInfo _ LFBlackHole _) = True
+closureUpdReqd (ClosureInfo { closureLFInfo = LFThunk _ _ upd _ _ }) = upd
+closureUpdReqd (ClosureInfo { closureLFInfo = LFBlackHole _ }) = True
-- Black-hole closures are allocated to receive the results of an
-- alg case with a named default... so they need to be updated.
-closureUpdReqd other_closure = False
+closureUpdReqd other_closure = False
closureSingleEntry :: ClosureInfo -> Bool
-
-closureSingleEntry (MkClosureInfo _ (LFThunk _ _ upd _) _) = not upd
-closureSingleEntry other_closure = False
-\end{code}
-
-Note: @closureType@ returns appropriately specialised tycon and
-datacons.
-\begin{code}
-closureType :: ClosureInfo -> Maybe (TyCon, [UniType], [Id])
-
--- First, a turgid special case. When we are generating the
--- standard code and info-table for Vaps (which is done when the function
--- defn is encountered), we don't have a convenient Id to hand whose
--- type is that of (f x y z). So we need to figure out the type
--- rather than take it from the Id. The Id is probably just "f"!
-
-closureType (MkClosureInfo id (LFThunk _ _ _ (VapThunk fun_id args _)) _)
- = getUniDataSpecTyCon_maybe (funResultTy de_foralld_ty (length args))
- where
- (_, de_foralld_ty) = splitForalls (getIdUniType fun_id)
-
-closureType (MkClosureInfo id lf _) = getUniDataSpecTyCon_maybe (getIdUniType id)
-\end{code}
-
-@closureReturnsUnboxedType@ is used to check whether a closure, {\em
-once it has eaten its arguments}, returns an unboxed type. For
-example, the closure for a function:
-\begin{verbatim}
- f :: Int -> Int#
-\end{verbatim}
-returns an unboxed type. This is important when dealing with stack
-overflow checks.
-\begin{code}
-closureReturnsUnboxedType :: ClosureInfo -> Bool
-
-closureReturnsUnboxedType (MkClosureInfo fun_id (LFReEntrant _ arity _) _)
- = isPrimType (funResultTy de_foralld_ty arity)
- where
- (_, de_foralld_ty) = splitForalls (getIdUniType fun_id)
-
-closureReturnsUnboxedType other_closure = False
- -- All non-function closures aren't functions,
- -- and hence are boxed, since they are heap alloc'd
+closureSingleEntry (ClosureInfo { closureLFInfo = LFThunk _ _ upd _ _}) = not upd
+closureSingleEntry other_closure = False
+
+closureReEntrant :: ClosureInfo -> Bool
+closureReEntrant (ClosureInfo { closureLFInfo = LFReEntrant _ _ _ _ }) = True
+closureReEntrant other_closure = False
+
+isConstrClosure_maybe :: ClosureInfo -> Maybe DataCon
+isConstrClosure_maybe (ConInfo { closureCon = data_con }) = Just data_con
+isConstrClosure_maybe _ = Nothing
+
+closureFunInfo :: ClosureInfo -> Maybe (Int, ArgDescr)
+closureFunInfo (ClosureInfo { closureLFInfo = LFReEntrant _ arity _ arg_desc})
+ = Just (arity, arg_desc)
+closureFunInfo _
+ = Nothing
\end{code}
\begin{code}
-closureSemiTag :: ClosureInfo -> Int
-
-closureSemiTag (MkClosureInfo _ lf_info _)
+isToplevClosure :: ClosureInfo -> Bool
+isToplevClosure (ClosureInfo { closureLFInfo = lf_info })
= case lf_info of
- LFCon data_con _ -> getDataConTag data_con - fIRST_TAG
- LFTuple _ _ -> 0
- --UNUSED: LFIndirection -> fromInteger iND_TAG
- _ -> fromInteger oTHER_TAG
+ LFReEntrant TopLevel _ _ _ -> True
+ LFThunk TopLevel _ _ _ _ -> True
+ other -> False
+isToplevClosure _ = False
\end{code}
Label generation.
\begin{code}
infoTableLabelFromCI :: ClosureInfo -> CLabel
-
-infoTableLabelFromCI (MkClosureInfo id lf_info rep)
+infoTableLabelFromCI (ClosureInfo { closureName = name,
+ closureLFInfo = lf_info,
+ closureSMRep = rep })
= case lf_info of
- LFCon con _ -> mkConInfoPtr con rep
- LFTuple tup _ -> mkConInfoPtr tup rep
-
- LFBlackHole -> mkBlackHoleInfoTableLabel
-
- LFThunk _ _ upd_flag (VapThunk fun_id args _) -> mkVapInfoTableLabel fun_id upd_flag
- -- Use the standard vap info table
- -- for the function, rather than a one-off one
- -- for this particular closure
+ LFBlackHole info -> info
-{- For now, we generate individual info table and entry code for selector thunks,
- so their info table should be labelled in the standard way.
- The only special thing about them is that the info table has a field which
- tells the GC that it really is a selector.
+ LFThunk _ _ upd_flag (SelectorThunk offset) _ ->
+ mkSelectorInfoLabel upd_flag offset
- Later, perhaps, we'll have some standard RTS code for selector-thunk info tables,
- in which case this line will spring back to life.
+ LFThunk _ _ upd_flag (ApThunk arity) _ ->
+ mkApInfoTableLabel upd_flag arity
- LFThunk _ _ upd_flag (SelectorThunk _ _ offset) -> mkSelectorInfoTableLabel upd_flag offset
- -- Ditto for selectors
--}
+ LFThunk{} -> mkInfoTableLabel name
- other -> {-NO: if isStaticRep rep
- then mkStaticInfoTableLabel id
- else -} mkInfoTableLabel id
+ LFReEntrant _ _ _ _ -> mkInfoTableLabel name
-mkConInfoPtr :: Id -> SMRep -> CLabel
-mkConInfoPtr id rep =
- case rep of
- PhantomRep -> mkPhantomInfoTableLabel id
- StaticRep _ _ -> mkStaticInfoTableLabel id
- _ -> mkInfoTableLabel id
+ other -> panic "infoTableLabelFromCI"
-mkConEntryPtr :: Id -> SMRep -> CLabel
-mkConEntryPtr id rep =
- case rep of
- StaticRep _ _ -> mkStaticConEntryLabel id
- _ -> mkConEntryLabel id
+infoTableLabelFromCI (ConInfo { closureCon = con, closureSMRep = rep })
+ = mkConInfoPtr con rep
-closureLabelFromCI (MkClosureInfo id _ _) = mkClosureLabel id
-
-entryLabelFromCI :: ClosureInfo -> CLabel
-entryLabelFromCI (MkClosureInfo id lf_info rep)
- = case lf_info of
- LFThunk _ _ upd_flag std_form_info -> thunkEntryLabel id std_form_info upd_flag
- LFCon con _ -> mkConEntryPtr con rep
- LFTuple tup _ -> mkConEntryPtr tup rep
- other -> mkStdEntryLabel id
-
--- thunkEntryLabel is a local help function, not exported. It's used from both
--- entryLabelFromCI and getEntryConvention.
--- I don't think it needs to deal with the SelectorThunk case
--- Well, it's falling over now, so I've made it deal with it. (JSM)
-
-thunkEntryLabel thunk_id (VapThunk fun_id args _) is_updatable
- = mkVapEntryLabel fun_id is_updatable
-thunkEntryLabel thunk_id _ is_updatable
- = mkStdEntryLabel thunk_id
-
-fastLabelFromCI :: ClosureInfo -> CLabel
-fastLabelFromCI (MkClosureInfo id _ _) = mkFastEntryLabel id fun_arity
+mkConInfoPtr :: DataCon -> SMRep -> CLabel
+mkConInfoPtr con rep
+ | isStaticRep rep = mkStaticInfoTableLabel name
+ | otherwise = mkConInfoTableLabel name
where
- arity_maybe = arityMaybe (getIdArity id)
- fun_arity = case arity_maybe of
- Just x -> x
- _ -> pprPanic "fastLabelFromCI:no arity:" (ppr PprShowAll id)
-\end{code}
+ name = dataConName con
-\begin{code}
-allocProfilingMsg :: ClosureInfo -> FAST_STRING
+closureLabelFromCI (ClosureInfo { closureName = nm }) = mkClosureLabel nm
+closureLabelFromCI _ = panic "closureLabelFromCI"
-allocProfilingMsg (MkClosureInfo _ lf_info _)
- = case lf_info of
- LFReEntrant _ _ _ -> SLIT("ALLOC_FUN")
- LFCon _ _ -> SLIT("ALLOC_CON")
- LFTuple _ _ -> SLIT("ALLOC_CON")
- LFThunk _ _ _ _ -> SLIT("ALLOC_THK")
- LFBlackHole -> SLIT("ALLOC_BH")
- --UNUSED: LFIndirection -> panic "ALLOC_IND"
- LFImported -> panic "ALLOC_IMP"
+-- thunkEntryLabel is a local help function, not exported. It's used from both
+-- entryLabelFromCI and getCallMethod.
+
+thunkEntryLabel thunk_id (ApThunk arity) is_updatable
+ = enterApLabel is_updatable arity
+thunkEntryLabel thunk_id (SelectorThunk offset) upd_flag
+ = enterSelectorLabel upd_flag offset
+thunkEntryLabel thunk_id _ is_updatable
+ = enterIdLabel thunk_id
+
+enterApLabel is_updatable arity
+ | tablesNextToCode = mkApInfoTableLabel is_updatable arity
+ | otherwise = mkApEntryLabel is_updatable arity
+
+enterSelectorLabel upd_flag offset
+ | tablesNextToCode = mkSelectorInfoLabel upd_flag offset
+ | otherwise = mkSelectorEntryLabel upd_flag offset
+
+enterIdLabel id
+ | tablesNextToCode = mkInfoTableLabel id
+ | otherwise = mkEntryLabel id
+
+enterReturnPtLabel name
+ | tablesNextToCode = mkReturnInfoLabel name
+ | otherwise = mkReturnPtLabel name
\end{code}
-We need a black-hole closure info to pass to @allocDynClosure@
-when we want to allocate the black hole on entry to a CAF.
-
-\begin{code}
-blackHoleClosureInfo (MkClosureInfo id _ _) = MkClosureInfo id LFBlackHole BlackHoleRep
-\end{code}
-The register liveness when returning from a constructor. For simplicity,
-we claim just [node] is live for all but PhantomRep's. In truth, this means
-that non-constructor info tables also claim node, but since their liveness
-information is never used, we don't care.
+We need a black-hole closure info to pass to @allocDynClosure@ when we
+want to allocate the black hole on entry to a CAF. These are the only
+ways to build an LFBlackHole, maintaining the invariant that it really
+is a black hole and not something else.
\begin{code}
-
-dataConLiveness isw_chkr (MkClosureInfo con _ PhantomRep)
- = case (dataReturnConvAlg isw_chkr con) of
- ReturnInRegs regs -> mkLiveRegsBitMask regs
- ReturnInHeap -> panic "dataConLiveness:PhantomRep in heap???"
-
-dataConLiveness _ _ = mkLiveRegsBitMask [node]
+cafBlackHoleClosureInfo (ClosureInfo { closureName = nm,
+ closureType = ty })
+ = ClosureInfo { closureName = nm,
+ closureLFInfo = LFBlackHole mkCAFBlackHoleInfoTableLabel,
+ closureSMRep = BlackHoleRep,
+ closureSRT = NoC_SRT,
+ closureType = ty,
+ closureDescr = "" }
+cafBlackHoleClosureInfo _ = panic "cafBlackHoleClosureInfo"
+
+seCafBlackHoleClosureInfo (ClosureInfo { closureName = nm,
+ closureType = ty })
+ = ClosureInfo { closureName = nm,
+ closureLFInfo = LFBlackHole mkSECAFBlackHoleInfoTableLabel,
+ closureSMRep = BlackHoleRep,
+ closureSRT = NoC_SRT,
+ closureType = ty,
+ closureDescr = "" }
+seCafBlackHoleClosureInfo _ = panic "seCafBlackHoleClosureInfo"
\end{code}
%************************************************************************
%* *
%************************************************************************
-Profiling requires three pices of information to be determined for
-each closure's info table --- kind, description and type.
+Profiling requires two pieces of information to be determined for
+each closure's info table --- description and type.
The description is stored directly in the @CClosureInfoTable@ when the
info table is built.
-The kind is determined from the @LambdaForm@ stored in the closure
-info using @closureKind@.
-
The type is determined from the type information stored with the @Id@
in the closure info using @closureTypeDescr@.
\begin{code}
-closureKind :: ClosureInfo -> String
-
-closureKind (MkClosureInfo _ lf _)
- = case lf of
- LFReEntrant _ n _ -> if n > 0 then "FN_K" else "THK_K"
- LFCon _ _ -> "CON_K"
- LFTuple _ _ -> "CON_K"
- LFThunk _ _ _ _ -> "THK_K"
- LFBlackHole -> "THK_K" -- consider BHs as thunks for the moment... (ToDo?)
- --UNUSED: LFIndirection -> panic "IND_KIND"
- LFImported -> panic "IMP_KIND"
-
-closureTypeDescr :: ClosureInfo -> String
-closureTypeDescr (MkClosureInfo id lf _)
- = if (isDataCon id) then -- DataCon has function types
- _UNPK_ (getOccurrenceName (getDataConTyCon id)) -- We want the TyCon not the ->
- else
- getUniTyDescription (getIdUniType id)
+closureValDescr, closureTypeDescr :: ClosureInfo -> String
+closureValDescr (ClosureInfo {closureDescr = descr})
+ = descr
+closureValDescr (ConInfo {closureCon = con})
+ = occNameUserString (getOccName con)
+
+closureTypeDescr (ClosureInfo { closureType = ty })
+ = getTyDescription ty
+closureTypeDescr (ConInfo { closureCon = data_con })
+ = occNameUserString (getOccName (dataConTyCon data_con))
+
+getTyDescription :: Type -> String
+getTyDescription ty
+ = case (tcSplitSigmaTy ty) of { (_, _, tau_ty) ->
+ case tau_ty of
+ TyVarTy _ -> "*"
+ AppTy fun _ -> getTyDescription fun
+ FunTy _ res -> '-' : '>' : fun_result res
+ NewTcApp tycon _ -> getOccString tycon
+ TyConApp tycon _ -> getOccString tycon
+ NoteTy (FTVNote _) ty -> getTyDescription ty
+ NoteTy (SynNote ty1) _ -> getTyDescription ty1
+ PredTy sty -> getPredTyDescription sty
+ ForAllTy _ ty -> getTyDescription ty
+ }
+ where
+ fun_result (FunTy _ res) = '>' : fun_result res
+ fun_result other = getTyDescription other
+
+getPredTyDescription (ClassP cl tys) = getOccString cl
+getPredTyDescription (IParam ip ty) = getOccString (ipNameName ip)
\end{code}
+
projects / ghc-hetmet.git / blobdiff