-
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
%
-\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}
module ClosureInfo (
ClosureInfo, LambdaFormInfo, SMRep, -- all abstract
- StandardFormInfo,
+ StandardFormInfo,
- EntryConvention(..),
+ ArgDescr(..), Liveness(..),
+ C_SRT(..), needsSRT,
- mkClosureLFInfo, mkConLFInfo, mkSelectorLFInfo, mkVapLFInfo,
- mkLFImported, mkLFArgument, mkLFLetNoEscape,
- UpdateFlag,
+ mkLFThunk, mkLFReEntrant, mkConLFInfo, mkSelectorLFInfo,
+ mkApLFInfo, mkLFImported, mkLFArgument, mkLFLetNoEscape,
- closureSize, closureHdrSize,
- closureNonHdrSize, closureSizeWithoutFixedHdr,
+ mkClosureInfo, mkConInfo,
+
+ closureSize, closureNonHdrSize,
closureGoodStuffSize, closurePtrsSize,
- slopSize, fitsMinUpdSize,
+ slopSize,
+
+ closureName, infoTableLabelFromCI,
+ closureLabelFromCI, closureSRT,
+ closureLFInfo, isLFThunk,closureSMRep, closureUpdReqd,
+ closureNeedsUpdSpace, closureIsThunk,
+ closureSingleEntry, closureReEntrant, isConstrClosure_maybe,
+ closureFunInfo, isStandardFormThunk, isKnownFun,
- layOutDynClosure, layOutDynCon, layOutStaticClosure,
- layOutStaticNoFVClosure, layOutPhantomClosure,
- mkVirtHeapOffsets,
+ enterIdLabel, enterLocalIdLabel, enterReturnPtLabel,
- nodeMustPointToIt, getEntryConvention,
- FCode, CgInfoDownwards, CgState,
+ nodeMustPointToIt,
+ CallMethod(..), getCallMethod,
blackHoleOnEntry,
staticClosureRequired,
- slowFunEntryCodeRequired, funInfoTableRequired,
- stdVapRequired, noUpdVapRequired,
- StgBinderInfo,
-
- closureId, infoTableLabelFromCI, fastLabelFromCI,
- closureLabelFromCI,
- entryLabelFromCI,
- closureLFInfo, closureSMRep, closureUpdReqd,
- closureSingleEntry, closureSemiTag, closureType,
- closureReturnsUnpointedType, getStandardFormThunkInfo,
- GenStgArg,
+ getClosureType,
isToplevClosure,
- closureKind, closureTypeDescr, -- profiling
+ closureValDescr, closureTypeDescr, -- profiling
- isStaticClosure, allocProfilingMsg,
- blackHoleClosureInfo,
- maybeSelectorInfo,
+ isStaticClosure,
+ cafBlackHoleClosureInfo, seCafBlackHoleClosureInfo,
- dataConLiveness -- concurrency
+ staticClosureNeedsLink,
) where
+#include "../includes/MachDeps.h"
#include "HsVersions.h"
-import AbsCSyn ( MagicId, node, mkLiveRegsMask,
- {- GHC 0.29 only -} AbstractC, CAddrMode
- )
import StgSyn
-import CgMonad
-
-import Constants ( mIN_UPD_SIZE, mIN_SIZE_NonUpdHeapObject,
- mAX_SPEC_ALL_PTRS, mAX_SPEC_MIXED_FIELDS,
- mAX_SPEC_ALL_NONPTRS,
- oTHER_TAG
- )
-import CgRetConv ( assignRegs, dataReturnConvAlg,
- DataReturnConvention(..)
- )
-import CLabel ( CLabel, mkStdEntryLabel, mkFastEntryLabel,
- mkPhantomInfoTableLabel, mkInfoTableLabel,
- mkConInfoTableLabel, mkStaticClosureLabel,
- mkBlackHoleInfoTableLabel, mkVapInfoTableLabel,
- mkStaticInfoTableLabel, mkStaticConEntryLabel,
- mkConEntryLabel, mkClosureLabel, mkVapEntryLabel
- )
-import CmdLineOpts ( opt_SccProfilingOn, opt_ForConcurrent )
-import HeapOffs ( intOff, addOff, totHdrSize, varHdrSize,
- VirtualHeapOffset, HeapOffset
- )
-import Id ( idType, getIdArity,
- externallyVisibleId,
- dataConTag, fIRST_TAG,
- isDataCon, isNullaryDataCon, dataConTyCon,
- isTupleCon, DataCon,
- GenId{-instance Eq-}, Id
- )
-import IdInfo ( ArityInfo(..) )
-import Maybes ( maybeToBool )
-import Name ( getOccString )
-import PprType ( getTyDescription )
-import PrelInfo ( maybeCharLikeCon, maybeIntLikeCon )
-import PrimRep ( getPrimRepSize, separateByPtrFollowness, PrimRep )
import SMRep -- all of it
-import TyCon ( TyCon, isNewTyCon )
-import Type ( isUnpointedType, splitForAllTys, splitFunTys, mkFunTys,
- splitAlgTyConApp_maybe, applyTys,
- Type
- )
-import Util ( isIn, mapAccumL )
-import Outputable
-import GlaExts --tmp
-\end{code}
-The ``wrapper'' data type for closure information:
+import CLabel
+
+import Constants ( mIN_PAYLOAD_SIZE )
+import Packages ( isDllName, HomeModules )
+import StaticFlags ( opt_SccProfilingOn, opt_OmitBlackHoling,
+ opt_Parallel, opt_DoTickyProfiling )
+import Id ( Id, idType, idArity, idName )
+import DataCon ( DataCon, dataConTyCon, isNullaryRepDataCon, dataConName )
+import Name ( Name, nameUnique, getOccName, getOccString )
+import OccName ( occNameString )
+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
-\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 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@)}
-
-\begin{verbatim}
- x = {y,ys} \ {} Cons {y,ys} -- Std form constructor
-\end{verbatim}
-
-x-closure: Cons-info-table, y-closure, ys-closure
-
-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}
-
- So if x is entered, Node will be set up and
- we'll jump direct to the Cons code.
-
-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}
-
- If x is entered, we'll jump to x-entry, which will set up Node
- before jumping to the standard Cons code
-
-{\em Top level non-constructors (@mkStaticEntryInfo@)}
-\begin{verbatim}
- x = ...
-\end{verbatim}
-
-For updatable thunks, x-entry must push an allocated BH in update frame, not Node.
-
-For non-zero arity, arg satis check must load Node before jumping to
- UpdatePAP.
-
-x's EntryInfo in its own module:
-\begin{verbatim}
- Base-label = x
- NodeMustPoint = False
- ClosureClass = whatever
-\end{verbatim}
-
-{\em Inner constructors (@mkConEntryInfo@)}
-
-\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}
+Information about a closure, from the code generator's point of view.
-{\em Inner non-constructors (@mkEntryInfo@)}
+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)
-\begin{verbatim}
- Base-label = x
- NodeMustPoint = True -- If no free vars, would have been
- -- lifted to top level
- ClosureClass = whatever
-\end{verbatim}
+We make a ClosureInfo for
+ - each let binding (both top level and not)
+ - each data constructor (for its shared static and
+ dynamic info tables)
-{\em Imported}
-
-\begin{verbatim}
- Nothing,
- or
- Base-label = x
- NodeMustPoint = False
- ClosureClass = whatever
-\end{verbatim}
-
-==============
-THINK: we could omit making Node point to top-level constructors
-of arity zero; but that might interact nastily with updates.
-==============
-
-
-==========
-The info we need to import for imported things is:
-
-\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}
-
-ToDo: move this stuff???
-
-\begin{pseudocode}
-mkStaticEntryInfo lbl cl_class
- = MkEntryInfo lbl False cl_class
-
-mkStaticConEntryInfo lbl
- = MkEntryInfo lbl True ConstructorClosure
-
-mkEntryInfo lbl cl_class
- = MkEntryInfo lbl True cl_class
-
-mkConEntryInfo lbl
- = MkEntryInfo lbl True ConstructorClosure
-\end{pseudocode}
-
-%************************************************************************
-%* *
-\subsection[ClosureInfo-datatypes]{Data types for closure information}
-%* *
-%************************************************************************
+\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,
+ closureDllCon :: !Bool -- is in a separate DLL
+ }
+
+-- 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}
%************************************************************************
%* *
%* *
%************************************************************************
+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.
+
+Note that a closure is usually bound to an identifier, so a
+ClosureInfo contains a LambdaFormInfo.
+
\begin{code}
data LambdaFormInfo
- = LFReEntrant -- Reentrant closure; used for PAPs too
- Bool -- True if top level
- Int -- Arity
- Bool -- True <=> no fvs
+ = 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)
- | 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
+ | LFCon -- A saturated constructor application
+ DataCon -- The constructor
| LFThunk -- Thunk (zero arity)
- Bool -- True <=> top level
- Bool -- True <=> no free vars
- Bool -- True <=> updatable (i.e., *not* single-entry)
+ TopLevelFlag
+ !Bool -- True <=> no free vars
+ !Bool -- True <=> updatable (i.e., *not* single-entry)
StandardFormInfo
+ !Bool -- True <=> *might* be a function type
- | LFArgument -- Used for function arguments. We know nothing about
- -- this closure. Treat like updatable "LFThunk"...
-
- | LFImported -- Used for imported things. We know nothing about this
- -- closure. Treat like updatable "LFThunk"...
+ | 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
| LFLetNoEscape -- See LetNoEscape module for precise description of
-- these "lets".
- Int -- arity;
- StgLiveVars-- list of variables live in the RHS of the let.
- -- (ToDo: maybe not used)
+ !Int -- arity;
| 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).
- -- 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
+-------------------------
+-- An ArgDsecr describes the argument pattern of a function
- | 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.)
+data ArgDescr
+ = ArgSpec -- Fits one of the standard patterns
+ !Int -- RTS type identifier ARG_P, ARG_N, ...
-{- A SelectorThunk is of form
+ | ArgGen -- General case
+ Liveness -- Details about the arguments
- 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.
--}
+-------------------------
+-- 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.
- | VapThunk
- Id -- Function
- [StgArg] -- Args
- Bool -- True <=> the function is not top-level, so
- -- must be stored in the thunk too
+data Liveness
+ = SmallLiveness -- Liveness info that fits in one word
+ StgWord -- Here's the bitmap
-{- A VapThunk is of form
+ | BigLiveness -- Liveness info witha a multi-word bitmap
+ CLabel -- Label for the bitmap
- 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.
--}
+-------------------------
+-- StandardFormInfo tells whether this thunk has one of
+-- a small number of standard forms
+data StandardFormInfo
+ = NonStandardThunk
+ -- Not of of the standard forms
-mkLFArgument = LFArgument
-mkLFBlackHole = LFBlackHole
-mkLFLetNoEscape = LFLetNoEscape
+ | 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.)
-mkLFImported :: Id -> LambdaFormInfo
-mkLFImported id
- = case getIdArity id of
- ArityExactly 0 -> LFThunk True{-top-lev-} True{-no fvs-}
- True{-updatable-} NonStandardThunk
- ArityExactly n -> LFReEntrant True n True -- n > 0
- other -> LFImported -- Not sure of exact arity
+ | 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}
%************************************************************************
%* *
%************************************************************************
-@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
- -> LambdaFormInfo
+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}
-mkClosureLFInfo top fvs upd_flag args@(_:_) -- Non-empty args
- = LFReEntrant top (length args) (null fvs)
+@mkConLFInfo@ is similar, for constructors.
-mkClosureLFInfo top fvs ReEntrant []
- = LFReEntrant top 0 (null fvs)
+\begin{code}
+mkConLFInfo :: DataCon -> LambdaFormInfo
+mkConLFInfo con = LFCon con
-mkClosureLFInfo top fvs upd_flag []
- = LFThunk top (null fvs) (isUpdatable upd_flag) NonStandardThunk
+mkSelectorLFInfo id offset updatable
+ = LFThunk NotTopLevel False updatable (SelectorThunk offset)
+ (might_be_a_function (idType id))
-isUpdatable ReEntrant = False
-isUpdatable SingleEntry = False
-isUpdatable Updatable = True
+mkApLFInfo id upd_flag arity
+ = LFThunk NotTopLevel (arity == 0) (isUpdatable upd_flag) (ApThunk arity)
+ (might_be_a_function (idType id))
\end{code}
-@mkConLFInfo@ is similar, for constructors.
+Miscellaneous LF-infos.
\begin{code}
-mkConLFInfo :: DataCon -> LambdaFormInfo
+mkLFArgument id = LFUnknown (might_be_a_function (idType id))
-mkConLFInfo con
- = -- the isNullaryDataCon will do this: ASSERT(isDataCon con)
- (if isTupleCon con then LFTuple else LFCon) con (isNullaryDataCon con)
-
-mkSelectorLFInfo scrutinee con offset
- = LFThunk False False True (SelectorThunk scrutinee con offset)
+mkLFLetNoEscape = LFLetNoEscape
-mkVapLFInfo fvs upd_flag fun_id args fun_in_vap
- = LFThunk False (null fvs) (isUpdatable upd_flag) (VapThunk fun_id args fun_in_vap)
+mkLFImported :: Id -> LambdaFormInfo
+mkLFImported id
+ = 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}
+\begin{code}
+isLFThunk :: LambdaFormInfo -> Bool
+isLFThunk (LFThunk _ _ _ _ _) = True
+isLFThunk (LFBlackHole _) = True
+ -- return True for a blackhole: this function is used to determine
+ -- whether to use the thunk header in SMP mode, and a blackhole
+ -- must have one.
+isLFThunk _ = False
+\end{code}
%************************************************************************
%* *
-\subsection[ClosureInfo-sizes]{Functions about closure {\em sizes}}
+ Building ClosureInfos
%* *
%************************************************************************
\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))
+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
+ name = idName id
+ sm_rep = chooseSMRep is_static lf_info tot_wds ptr_wds
+
+mkConInfo :: HomeModules
+ -> Bool -- Is static
+ -> DataCon
+ -> Int -> Int -- Total and pointer words
+ -> ClosureInfo
+mkConInfo hmods is_static data_con tot_wds ptr_wds
+ = ConInfo { closureSMRep = sm_rep,
+ closureCon = data_con,
+ closureDllCon = isDllName hmods (dataConName data_con) }
+ where
+ sm_rep = chooseSMRep is_static (mkConLFInfo data_con) tot_wds ptr_wds
+\end{code}
-closureHdrSize :: ClosureInfo -> HeapOffset
-closureHdrSize (MkClosureInfo _ _ sm_rep)
- = totHdrSize sm_rep
+%************************************************************************
+%* *
+\subsection[ClosureInfo-sizes]{Functions about closure {\em sizes}}
+%* *
+%************************************************************************
-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?
+\begin{code}
+closureSize :: ClosureInfo -> WordOff
+closureSize cl_info = hdr_size + closureNonHdrSize cl_info
+ where hdr_size | closureIsThunk cl_info = thunkHdrSize
+ | otherwise = fixedHdrSize
+ -- All thunks use thunkHdrSize, even if they are non-updatable.
+ -- this is because we don't have separate closure types for
+ -- updatable vs. non-updatable thunks, so the GC can't tell the
+ -- difference. If we ever have significant numbers of non-
+ -- updatable thunks, it might be worth fixing this.
+
+closureNonHdrSize :: ClosureInfo -> WordOff
+closureNonHdrSize cl_info
+ = tot_wds + computeSlopSize tot_wds cl_info
where
tot_wds = closureGoodStuffSize cl_info
-closureGoodStuffSize :: ClosureInfo -> Int
-closureGoodStuffSize (MkClosureInfo _ _ sm_rep)
- = let (ptrs, nonptrs) = sizes_from_SMRep sm_rep
+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
knowledge of what the storage manager does with the various
representations...
-Slop Requirements:
-\begin{itemize}
-\item
-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
- \end{itemize}
-THEREFORE: @mIN_UPD_SIZE = 2@.
-
-\item
-Collectable closures which are allocated in the heap
-must be @mIN_SIZE_NonUpdHeapObject@.
-
-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}
+Slop Requirements: every thunk gets an extra padding word in the
+header, which takes the the updated value.
\begin{code}
-slopSize cl_info@(MkClosureInfo _ lf_info sm_rep)
- = computeSlopSize (closureGoodStuffSize cl_info) sm_rep (closureUpdReqd cl_info)
-
-computeSlopSize :: Int -> SMRep -> Bool -> Int
-
-computeSlopSize tot_wds (SpecialisedRep ConstantRep _ _ _) _
- = 0
-computeSlopSize tot_wds (SpecialisedRep CharLikeRep _ _ _) _
- = 0
-
-computeSlopSize tot_wds (SpecialisedRep _ _ _ _) 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}
-%* *
-%************************************************************************
+slopSize cl_info = computeSlopSize payload_size cl_info
+ where payload_size = closureGoodStuffSize cl_info
-\begin{code}
-layOutDynClosure, layOutStaticClosure
- :: Id -- STG identifier w/ which this closure assoc'd
- -> (a -> PrimRep) -- function w/ which to be able to get a PrimRep
- -> [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)
+computeSlopSize :: WordOff -> ClosureInfo -> WordOff
+computeSlopSize payload_size cl_info
+ = max 0 (minPayloadSize smrep updatable - payload_size)
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)
+ smrep = closureSMRep cl_info
+ updatable = closureNeedsUpdSpace cl_info
+
+-- 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
+
+minPayloadSize :: SMRep -> Bool -> WordOff
+minPayloadSize smrep updatable
+ = case smrep of
+ BlackHoleRep -> min_upd_size
+ GenericRep _ _ _ _ | updatable -> min_upd_size
+ GenericRep True _ _ _ -> 0 -- static
+ GenericRep False _ _ _ -> mIN_PAYLOAD_SIZE
+ -- ^^^^^___ dynamic
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}
-
-A wrapper for when used with data constructors:
-\begin{code}
-layOutDynCon :: DataCon
- -> (a -> PrimRep)
- -> [a]
- -> (ClosureInfo, [(a,VirtualHeapOffset)])
-
-layOutDynCon con kind_fn args
- = ASSERT(isDataCon con)
- layOutDynClosure con kind_fn args (mkConLFInfo con)
+ min_upd_size =
+ ASSERT(mIN_PAYLOAD_SIZE <= sIZEOF_StgSMPThunkHeader)
+ 0 -- check that we already have enough
+ -- room for mIN_SIZE_NonUpdHeapObject,
+ -- due to the extra header word in SMP
\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
-
- (LFCon con _ ) -> if maybeCharLikeCon con then CharLikeRep
- else if maybeIntLikeCon con then IntLikeRep
- else SpecRep
-
- _ -> SpecRep
- in
- SpecialisedRep spec_kind ptr_wds nonptr_wds updatekind
- else
- GenericRep ptr_wds nonptr_wds updatekind
-\end{code}
+-- 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.
-
-%************************************************************************
-%* *
-\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 -> PrimRep) -- 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 + (getPrimRepSize . 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
- = let
- do_profiling = opt_SccProfilingOn
- in
- 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
-- 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 NonStandardThunk
- -> 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)
- LFThunk _ no_fvs updatable some_standard_form_thunk
- -> returnFC True
- -- Node must point to any standard-form thunk.
- -- For example,
- -- x = f y
- -- generates a Vap thunk for (f y), and even if y is a global
- -- variable we must still make Node point to the thunk before entering it
- -- because that's what the standard-form code expects.
-
- LFArgument -> returnFC True
- LFImported -> returnFC True
- LFBlackHole -> returnFC True
- -- BH entry may require Node to point
-
- LFLetNoEscape _ _ -> returnFC False
+nodeMustPointToIt (LFThunk _ no_fvs updatable some_standard_form_thunk _)
+ = True -- Node must point to any standard-form thunk
+
+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,
(rather than directly) to catch double-entry.
\begin{code}
-data EntryConvention
- = ViaNode -- The "normal" convention
+data CallMethod
+ = EnterIt -- no args, not a function
- | StdEntry CLabel -- Jump to this code, with args on stack
- (Maybe CLabel) -- possibly setting infoptr to this
+ | JumpToIt CLabel -- no args, not a function, but we
+ -- know what its entry code is
- | DirectEntry -- Jump directly to code, with args in regs
- CLabel -- The code label
- Int -- Its arity
- [MagicId] -- Its register assignments (possibly empty)
+ | ReturnIt -- it's a function, but we have
+ -- zero args to apply to it, so just
+ -- return it.
-getEntryConvention :: Id -- Function being applied
- -> LambdaFormInfo -- Its info
- -> [PrimRep] -- Available arguments
- -> FCode EntryConvention
+ | ReturnCon DataCon -- It's a data constructor, just return it
-getEntryConvention id lf_info arg_kinds
- = nodeMustPointToIt lf_info `thenFC` \ node_points ->
- let
- is_concurrent = opt_ForConcurrent
- in
- 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 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
- mkConInfoTableLabel con
- in
- --false:ASSERT (null arg_kinds) -- Should have no args (meaning what?)
- StdEntry (mkConEntryLabel con) (Just itbl)
-
- LFTuple tup zero_arity
- -> --false:ASSERT (null arg_kinds) -- Should have no args (meaning what?)
- StdEntry (mkConEntryLabel tup) (Just (mkConInfoTableLabel tup))
-
- 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 live_regs arg_kinds
- live_regs = if node_points then [node] else []
- )
-
-blackHoleOnEntry :: Bool -- No-black-holing flag
- -> ClosureInfo
- -> Bool
+ | SlowCall -- Unknown fun, or known fun with
+ -- too few args.
+
+ | DirectEntry -- Jump directly, with args in regs
+ CLabel -- The code label
+ Int -- Its arity
+getCallMethod :: HomeModules
+ -> Name -- Function being applied
+ -> LambdaFormInfo -- Its info
+ -> Int -- Number of available arguments
+ -> CallMethod
+
+getCallMethod hmods 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 hmods 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 hmods name) arity
+
+getCallMethod hmods name (LFCon con) n_args
+ = ASSERT( n_args == 0 )
+ ReturnCon con
+
+getCallMethod hmods 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
+ {- OLD: || opt_SMP
+ I decided to remove this, because in SMP mode it doesn't matter
+ if we enter the same thunk multiple times, so the optimisation
+ of jumping directly to the entry code is still valid. --SDM
+ -}
+ = ASSERT( n_args == 0 ) EnterIt
+
+ | otherwise -- Jump direct to code for single-entry thunks
+ = ASSERT( n_args == 0 )
+ JumpToIt (thunkEntryLabel hmods name std_form_info updatable)
+
+getCallMethod hmods name (LFUnknown True) n_args
+ = SlowCall -- might be a function
+
+getCallMethod hmods name (LFUnknown False) n_args
+ = ASSERT2 ( n_args == 0, ppr name <+> ppr n_args )
+ EnterIt -- Not a function
+
+getCallMethod hmods 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 hmods name (LFLetNoEscape 0) n_args
+ = JumpToIt (enterReturnPtLabel (nameUnique name))
+
+getCallMethod hmods 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
+ 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.
-getStandardFormThunkInfo
- :: LambdaFormInfo
- -> Maybe [StgArg] -- Nothing => not a standard-form thunk
- -- Just atoms => a standard-form thunk with payload atoms
+ other -> panic "blackHoleOnEntry" -- Should never happen
-getStandardFormThunkInfo (LFThunk _ _ _ (SelectorThunk scrutinee _ _))
- = --trace "Selector thunk: missed opportunity to save info table + code"
- Nothing
- -- Just [StgVarArg scrutinee]
- -- We can't save the info tbl + code until we have a way to generate
- -- a fixed family thereof.
+isStandardFormThunk :: LambdaFormInfo -> Bool
+isStandardFormThunk (LFThunk _ _ _ (SelectorThunk _) _) = True
+isStandardFormThunk (LFThunk _ _ _ (ApThunk _) _) = True
+isStandardFormThunk other_lf_info = False
-getStandardFormThunkInfo (LFThunk _ _ _ (VapThunk fun_id args fun_in_payload))
- | fun_in_payload = Just (StgVarArg fun_id : args)
- | otherwise = Just args
+isKnownFun :: LambdaFormInfo -> Bool
+isKnownFun (LFReEntrant _ _ _ _) = True
+isKnownFun (LFLetNoEscape _) = True
+isKnownFun _ = False
+\end{code}
-getStandardFormThunkInfo other_lf_info = Nothing
+-----------------------------------------------------------------------------
+SRT-related stuff
-maybeSelectorInfo (MkClosureInfo _ (LFThunk _ _ _ (SelectorThunk _ con offset)) _) = Just (con,offset)
-maybeSelectorInfo _ = Nothing
+\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 (isNullaryRepDataCon 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
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
+ :: Name
-> 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 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)
staticClosureRequired binder other_binder_info other_lf_info = True
-
-slowFunEntryCodeRequired -- Assumption: it's a function, not a thunk.
- :: Id
- -> StgBinderInfo
- -> EntryConvention
- -> Bool
-slowFunEntryCodeRequired binder (StgBinderInfo arg_occ unsat_occ _ _ _) entry_conv
- = arg_occ -- There's an argument occurrence
- || unsat_occ -- There's an unsaturated call
- || externallyVisibleId binder
- || (case entry_conv of { DirectEntry _ _ _ -> False; other -> True })
- {- The last case deals with the parallel world; a function usually
- as a DirectEntry convention, but if it doesn't we must generate slow-entry code -}
-
-slowFunEntryCodeRequired binder NoStgBinderInfo _ = True
-
-funInfoTableRequired
- :: Id
- -> 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
-
-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
-\end{code}
-
-@lfArity@ extracts the arity of a function from its LFInfo
-
-\begin{code}
-{- Not needed any more
-
-lfArity_maybe (LFReEntrant _ arity _) = Just arity
-
--- Removed SLPJ March 97. I don't believe these two;
--- LFCon is used for construcor *applications*, not constructors!
---
--- lfArity_maybe (LFCon con _) = Just (dataConArity con)
--- lfArity_maybe (LFTuple con _) = Just (dataConArity con)
-
-lfArity_maybe other = Nothing
--}
\end{code}
%************************************************************************
\begin{code}
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 ClosureInfo{ closureLFInfo = lf_info } = lfUpdatable lf_info
+closureUpdReqd ConInfo{} = False
-closureUpdReqd (MkClosureInfo _ (LFThunk _ _ upd _) _) = upd
-closureUpdReqd (MkClosureInfo _ LFBlackHole _) = True
+lfUpdatable :: LambdaFormInfo -> Bool
+lfUpdatable (LFThunk _ _ upd _ _) = upd
+lfUpdatable (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
+lfUpdatable _ = False
-closureSingleEntry :: ClosureInfo -> Bool
+closureIsThunk :: ClosureInfo -> Bool
+closureIsThunk ClosureInfo{ closureLFInfo = lf_info } = isLFThunk lf_info
+closureIsThunk ConInfo{} = False
-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, [Type], [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 _)) _)
- = splitAlgTyConApp_maybe (fun_result_ty (length args) (idType fun_id))
-
-closureType (MkClosureInfo id lf _) = splitAlgTyConApp_maybe (idType id)
-\end{code}
-
-@closureReturnsUnpointedType@ 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}
-closureReturnsUnpointedType :: ClosureInfo -> Bool
-
-closureReturnsUnpointedType (MkClosureInfo fun_id (LFReEntrant _ arity _) _)
- = isUnpointedType (fun_result_ty arity (idType fun_id))
-
-closureReturnsUnpointedType other_closure = False
- -- All non-function closures aren't functions,
- -- and hence are boxed, since they are heap alloc'd
-
--- fun_result_ty is a disgusting little bit of code that finds the result
--- type of a function application. It looks "through" new types.
--- We don't have type args available any more, so we are pretty cavilier,
--- and quite possibly plain wrong. Let's hope it doesn't matter if we are!
-
-fun_result_ty arity ty
- | arity <= n_arg_tys
- = mkFunTys (drop arity arg_tys) res_ty
-
- | otherwise
- = case splitAlgTyConApp_maybe res_ty of
- Nothing -> pprPanic "fun_result_ty:" (hsep [int arity,
- ppr ty])
-
- Just (tycon, tycon_arg_tys, [con]) | isNewTyCon tycon
- -> fun_result_ty (arity - n_arg_tys) rep_ty
- where
- ([rep_ty], _) = splitFunTys (applyTys (idType con) tycon_arg_tys)
- Just (_,_,cons) -> trace (showSDoc (ppr ty) ++ showSDoc(ppr cons)) $ panic "fun_result_ty"
- where
- (_, rho_ty) = splitForAllTys ty
- (arg_tys, res_ty) = splitFunTys rho_ty
- n_arg_tys = length arg_tys
-\end{code}
-
-\begin{code}
-closureSemiTag :: ClosureInfo -> Int
-
-closureSemiTag (MkClosureInfo _ lf_info _)
- = case lf_info of
- LFCon data_con _ -> dataConTag data_con - fIRST_TAG
- LFTuple _ _ -> 0
- _ -> fromInteger oTHER_TAG
+closureSingleEntry :: ClosureInfo -> Bool
+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}
isToplevClosure :: ClosureInfo -> Bool
-
-isToplevClosure (MkClosureInfo _ lf_info _)
+isToplevClosure (ClosureInfo { closureLFInfo = lf_info })
= case lf_info of
- LFReEntrant top _ _ -> top
- LFThunk top _ _ _ -> top
- _ -> panic "ClosureInfo:isToplevClosure"
+ LFReEntrant TopLevel _ _ _ -> True
+ LFThunk TopLevel _ _ _ _ -> True
+ other -> False
+isToplevClosure _ = False
\end{code}
Label generation.
\begin{code}
-fastLabelFromCI :: ClosureInfo -> CLabel
-fastLabelFromCI (MkClosureInfo id lf_info _)
-{- [SLPJ Changed March 97]
- (was ok, but is the only call to lfArity,
- and the id should guarantee to have the correct arity in it.
-
- = case lfArity_maybe lf_info of
- Just arity ->
--}
- = case getIdArity id of
- ArityExactly arity -> mkFastEntryLabel id arity
- other -> pprPanic "fastLabelFromCI" (ppr id)
-
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
-
-{- 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.
+ LFBlackHole info -> info
- 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 (SelectorThunk offset) _ ->
+ mkSelectorInfoLabel upd_flag offset
- LFThunk _ _ upd_flag (SelectorThunk _ _ offset) -> mkSelectorInfoTableLabel upd_flag offset
- -- Ditto for selectors
--}
+ LFThunk _ _ upd_flag (ApThunk arity) _ ->
+ mkApInfoTableLabel upd_flag arity
- other -> {-NO: if isStaticRep rep
- then mkStaticInfoTableLabel id
- else -} mkInfoTableLabel id
+ LFThunk{} -> mkLocalInfoTableLabel name
-mkConInfoPtr :: Id -> SMRep -> CLabel
-mkConInfoPtr con rep
- = ASSERT(isDataCon con)
- case rep of
- PhantomRep -> mkPhantomInfoTableLabel con
- StaticRep _ _ -> mkStaticInfoTableLabel con
- _ -> mkConInfoTableLabel con
+ LFReEntrant _ _ _ _ -> mkLocalInfoTableLabel name
-mkConEntryPtr :: Id -> SMRep -> CLabel
-mkConEntryPtr con rep
- = ASSERT(isDataCon con)
- case rep of
- StaticRep _ _ -> mkStaticConEntryLabel con
- _ -> mkConEntryLabel con
+ other -> panic "infoTableLabelFromCI"
+infoTableLabelFromCI (ConInfo { closureCon = con,
+ closureSMRep = rep,
+ closureDllCon = dll })
+ | isStaticRep rep = mkStaticInfoTableLabel name dll
+ | otherwise = mkConInfoTableLabel name dll
+ where
+ name = dataConName con
-closureLabelFromCI (MkClosureInfo id _ rep)
- | isConstantRep rep
- = mkStaticClosureLabel id
- -- This case catches those pesky static closures for nullary constructors
-
-closureLabelFromCI (MkClosureInfo id _ other_rep) = 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
+-- ClosureInfo for a closure (as opposed to a constructor) is always local
+closureLabelFromCI (ClosureInfo { closureName = nm }) = mkLocalClosureLabel nm
+closureLabelFromCI _ = panic "closureLabelFromCI"
-- 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
+-- entryLabelFromCI and getCallMethod.
+
+thunkEntryLabel hmods thunk_id (ApThunk arity) is_updatable
+ = enterApLabel is_updatable arity
+thunkEntryLabel hmods thunk_id (SelectorThunk offset) upd_flag
+ = enterSelectorLabel upd_flag offset
+thunkEntryLabel hmods thunk_id _ is_updatable
+ = enterIdLabel hmods 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 hmods id
+ | tablesNextToCode = mkInfoTableLabel hmods id
+ | otherwise = mkEntryLabel hmods id
+
+enterLocalIdLabel id
+ | tablesNextToCode = mkLocalInfoTableLabel id
+ | otherwise = mkLocalEntryLabel id
+
+enterReturnPtLabel name
+ | tablesNextToCode = mkReturnInfoLabel name
+ | otherwise = mkReturnPtLabel name
\end{code}
-\begin{code}
-allocProfilingMsg :: ClosureInfo -> FAST_STRING
-
-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")
- LFImported -> panic "ALLOC_IMP"
-\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.
+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 (MkClosureInfo con _ PhantomRep)
- = case (dataReturnConvAlg con) of
- ReturnInRegs regs -> mkLiveRegsMask regs
- ReturnInHeap -> panic "dataConLiveness:PhantomRep in heap???"
-
-dataConLiveness _ = mkLiveRegsMask [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?)
- LFImported -> panic "IMP_KIND"
-
-closureTypeDescr :: ClosureInfo -> String
-closureTypeDescr (MkClosureInfo id lf _)
- = if (isDataCon id) then -- DataCon has function types
- getOccString (dataConTyCon id) -- We want the TyCon not the ->
- else
- getTyDescription (idType id)
+closureValDescr, closureTypeDescr :: ClosureInfo -> String
+closureValDescr (ClosureInfo {closureDescr = descr})
+ = descr
+closureValDescr (ConInfo {closureCon = con})
+ = occNameString (getOccName con)
+
+closureTypeDescr (ClosureInfo { closureType = ty })
+ = getTyDescription ty
+closureTypeDescr (ConInfo { closureCon = data_con })
+ = occNameString (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
+ TyConApp tycon _ -> getOccString tycon
+ NoteTy (FTVNote _) ty -> getTyDescription ty
+ 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