X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FbasicTypes%2FId.lhs;h=5ac261255cb787d280a1bd86395b24d2622b6076;hp=95f90a45dbd326768b5aea3114fd28e65685b19b;hb=914e415702a25a6e52ab1eaaf2aea233d6c6097e;hpb=6084fb5517da34f65034370a3695e2af3b85ce2b diff --git a/compiler/basicTypes/Id.lhs b/compiler/basicTypes/Id.lhs index 95f90a4..5ac2612 100644 --- a/compiler/basicTypes/Id.lhs +++ b/compiler/basicTypes/Id.lhs @@ -5,127 +5,136 @@ \section[Id]{@Ids@: Value and constructor identifiers} \begin{code} +-- | +-- #name_types# +-- GHC uses several kinds of name internally: +-- +-- * 'OccName.OccName': see "OccName#name_types" +-- +-- * 'RdrName.RdrName': see "RdrName#name_types" +-- +-- * 'Name.Name': see "Name#name_types" +-- +-- * 'Id.Id' represents names that not only have a 'Name.Name' but also a 'TypeRep.Type' and some additional +-- details (a 'IdInfo.IdInfo' and one of 'Var.LocalIdDetails' or 'IdInfo.GlobalIdDetails') that +-- are added, modified and inspected by various compiler passes. These 'Var.Var' names may either +-- be global or local, see "Var#globalvslocal" +-- +-- * 'Var.Var': see "Var#name_types" module Id ( -- * The main types - Id, DictId, + Var, Id, isId, -- ** Simple construction mkGlobalId, mkVanillaGlobal, mkVanillaGlobalWithInfo, - mkLocalId, mkLocalIdWithInfo, + mkLocalId, mkLocalIdWithInfo, mkExportedLocalId, mkSysLocal, mkSysLocalM, mkUserLocal, mkUserLocalM, + mkTemplateLocals, mkTemplateLocalsNum, mkTemplateLocal, + mkWorkerId, mkWiredInIdName, -- ** Taking an Id apart - idName, idType, idUnique, idInfo, - isId, globalIdDetails, idPrimRep, - recordSelectorFieldLabel, + idName, idType, idUnique, idInfo, idDetails, + idPrimRep, recordSelectorFieldLabel, -- ** Modifying an Id - setIdName, setIdUnique, Id.setIdType, setIdExported, setIdNotExported, - globaliseId, setIdInfo, lazySetIdInfo, modifyIdInfo, maybeModifyIdInfo, + setIdName, setIdUnique, Id.setIdType, + setIdExported, setIdNotExported, + globaliseId, localiseId, + setIdInfo, lazySetIdInfo, modifyIdInfo, maybeModifyIdInfo, zapLamIdInfo, zapDemandIdInfo, zapFragileIdInfo, transferPolyIdInfo, + -- ** Predicates on Ids - isImplicitId, isDeadBinder, isDictId, isStrictId, + isImplicitId, isDeadBinder, + isStrictId, isExportedId, isLocalId, isGlobalId, isRecordSelector, isNaughtyRecordSelector, - isClassOpId_maybe, + isClassOpId_maybe, isDFunId, dfunNSilent, isPrimOpId, isPrimOpId_maybe, isFCallId, isFCallId_maybe, isDataConWorkId, isDataConWorkId_maybe, isDataConId_maybe, idDataCon, - isBottomingId, idIsFrom, + isConLikeId, isBottomingId, idIsFrom, isTickBoxOp, isTickBoxOp_maybe, hasNoBinding, - -- ** Inline pragma stuff - idInlinePragma, setInlinePragma, modifyInlinePragma, + -- ** Evidence variables + DictId, isDictId, isEvVar, evVarPred, + -- ** Inline pragma stuff + idInlinePragma, setInlinePragma, modifyInlinePragma, + idInlineActivation, setInlineActivation, idRuleMatchInfo, - -- ** One shot lambda stuff + -- ** One-shot lambdas isOneShotBndr, isOneShotLambda, isStateHackType, setOneShotLambda, clearOneShotLambda, - -- ** IdInfo stuff - setIdUnfolding, - setIdArity, - setIdNewDemandInfo, - setIdNewStrictness, zapIdNewStrictness, - setIdWorkerInfo, - setIdSpecialisation, - setIdCafInfo, - setIdOccInfo, - - -- ** Id demand information -#ifdef OLD_STRICTNESS - idDemandInfo, - idStrictness, - idCprInfo, - setIdStrictness, - setIdDemandInfo, - setIdCprInfo, -#endif - + -- ** Reading 'IdInfo' fields idArity, - idNewDemandInfo, idNewDemandInfo_maybe, - idNewStrictness, idNewStrictness_maybe, - idWorkerInfo, - idUnfolding, + idDemandInfo, idDemandInfo_maybe, + idStrictness, idStrictness_maybe, + idUnfolding, realIdUnfolding, idSpecialisation, idCoreRules, idHasRules, idCafInfo, idLBVarInfo, idOccInfo, -#ifdef OLD_STRICTNESS - newStrictnessFromOld -- Temporary -#endif + -- ** Writing 'IdInfo' fields + setIdUnfoldingLazily, + setIdUnfolding, + setIdArity, + setIdDemandInfo, + setIdStrictness, zapIdStrictness, + setIdSpecialisation, + setIdCafInfo, + setIdOccInfo, zapIdOccInfo, ) where #include "HsVersions.h" -import {-# SOURCE #-} CoreSyn ( CoreRule, Unfolding ) +import CoreSyn ( CoreRule, Unfolding( NoUnfolding ) ) import IdInfo import BasicTypes + +-- Imported and re-exported +import Var( Var, Id, DictId, EvVar, + idInfo, idDetails, globaliseId, varType, + isId, isLocalId, isGlobalId, isExportedId ) import qualified Var -import Var + import TyCon import Type -import TcType -import TysPrim -#ifdef OLD_STRICTNESS -import qualified Demand -#endif +import TysPrim import DataCon -import NewDemand +import Demand import Name import Module import Class import PrimOp import ForeignCall -import OccName import Maybes import SrcLoc import Outputable import Unique import UniqSupply import FastString +import Util( count ) import StaticFlags -- infixl so you can say (id `set` a `set` b) -infixl 1 `setIdUnfolding`, +infixl 1 `setIdUnfoldingLazily`, + `setIdUnfolding`, `setIdArity`, - `setIdNewDemandInfo`, - `setIdNewStrictness`, - `setIdWorkerInfo`, + `setIdOccInfo`, + `setIdDemandInfo`, + `setIdStrictness`, `setIdSpecialisation`, `setInlinePragma`, + `setInlineActivation`, `idCafInfo` -#ifdef OLD_STRICTNESS - ,`idCprInfo` - ,`setIdStrictness` - ,`setIdDemandInfo` -#endif \end{code} + %************************************************************************ %* * \subsection{Basic Id manipulation} @@ -137,34 +146,44 @@ idName :: Id -> Name idName = Var.varName idUnique :: Id -> Unique -idUnique = varUnique +idUnique = Var.varUnique idType :: Id -> Kind -idType = varType +idType = Var.varType -setIdUnique :: Id -> Unique -> Id -setIdUnique = setVarUnique +idPrimRep :: Id -> PrimRep +idPrimRep id = typePrimRep (idType id) setIdName :: Id -> Name -> Id -setIdName = setVarName +setIdName = Var.setVarName +setIdUnique :: Id -> Unique -> Id +setIdUnique = Var.setVarUnique + +-- | Not only does this set the 'Id' 'Type', it also evaluates the type to try and +-- reduce space usage setIdType :: Id -> Type -> Id setIdType id ty = seqType ty `seq` Var.setVarType id ty setIdExported :: Id -> Id -setIdExported = setIdVarExported +setIdExported = Var.setIdExported setIdNotExported :: Id -> Id -setIdNotExported = setIdVarNotExported - -globaliseId :: GlobalIdDetails -> Id -> Id -globaliseId = globaliseIdVar - -idInfo :: Id -> IdInfo -idInfo = varIdInfo +setIdNotExported = Var.setIdNotExported + +localiseId :: Id -> Id +-- Make an with the same unique and type as the +-- incoming Id, but with an *Internal* Name and *LocalId* flavour +localiseId id + | ASSERT( isId id ) isLocalId id && isInternalName name + = id + | otherwise + = mkLocalIdWithInfo (localiseName name) (idType id) (idInfo id) + where + name = idName id lazySetIdInfo :: Id -> IdInfo -> Id -lazySetIdInfo = lazySetVarIdInfo +lazySetIdInfo = Var.lazySetIdInfo setIdInfo :: Id -> IdInfo -> Id setIdInfo id info = seqIdInfo info `seq` (lazySetIdInfo id info) @@ -200,31 +219,36 @@ substitution (which changes the free type variables) is more common. Anyway, we removed it in March 2008. \begin{code} --- | Create a global Id. Global identifiers are those that are imported or are data constructors/destructors. -mkGlobalId :: GlobalIdDetails -> Name -> Type -> IdInfo -> Id -mkGlobalId = mkGlobalIdVar +-- | For an explanation of global vs. local 'Id's, see "Var#globalvslocal" +mkGlobalId :: IdDetails -> Name -> Type -> IdInfo -> Id +mkGlobalId = Var.mkGlobalVar +-- | Make a global 'Id' without any extra information at all mkVanillaGlobal :: Name -> Type -> Id mkVanillaGlobal name ty = mkVanillaGlobalWithInfo name ty vanillaIdInfo +-- | Make a global 'Id' with no global information but some generic 'IdInfo' mkVanillaGlobalWithInfo :: Name -> Type -> IdInfo -> Id -mkVanillaGlobalWithInfo = mkGlobalId VanillaGlobal +mkVanillaGlobalWithInfo = mkGlobalId VanillaId --- | Create a local Id. Local identifiers are those bound at the top level of the current module or in an expression. +-- | For an explanation of global vs. local 'Id's, see "Var#globalvslocal" mkLocalId :: Name -> Type -> Id mkLocalId name ty = mkLocalIdWithInfo name ty vanillaIdInfo mkLocalIdWithInfo :: Name -> Type -> IdInfo -> Id -mkLocalIdWithInfo = mkLocalIdVar +mkLocalIdWithInfo name ty info = Var.mkLocalVar VanillaId name ty info + -- Note [Free type variables] --- | Create a local Id that is marked as exported. This prevents things attached to it from being removed as dead code. +-- | Create a local 'Id' that is marked as exported. +-- This prevents things attached to it from being removed as dead code. mkExportedLocalId :: Name -> Type -> Id -mkExportedLocalId name ty = mkExportedLocalIdVar name ty vanillaIdInfo +mkExportedLocalId name ty = Var.mkExportedLocalVar VanillaId name ty vanillaIdInfo -- Note [Free type variables] --- | Create a system local Id. These are local Ids that are created by the compiler out of thin air +-- | Create a system local 'Id'. These are local 'Id's (see "Var#globalvslocal") +-- that are created by the compiler out of thin air mkSysLocal :: FastString -> Unique -> Type -> Id mkSysLocal fs uniq ty = mkLocalId (mkSystemVarName uniq fs) ty @@ -232,12 +256,16 @@ mkSysLocalM :: MonadUnique m => FastString -> Type -> m Id mkSysLocalM fs ty = getUniqueM >>= (\uniq -> return (mkSysLocal fs uniq ty)) --- | Create a user local Id. These are local Id with a name and location that the user might recognize +-- | Create a user local 'Id'. These are local 'Id's (see "Var#globalvslocal") with a name and location that the user might recognize mkUserLocal :: OccName -> Unique -> Type -> SrcSpan -> Id mkUserLocal occ uniq ty loc = mkLocalId (mkInternalName uniq occ loc) ty mkUserLocalM :: MonadUnique m => OccName -> Type -> SrcSpan -> m Id mkUserLocalM occ ty loc = getUniqueM >>= (\uniq -> return (mkUserLocal occ uniq ty loc)) + +mkWiredInIdName :: Module -> FastString -> Unique -> Id -> Name +mkWiredInIdName mod fs uniq id + = mkWiredInName mod (mkOccNameFS varName fs) uniq (AnId id) UserSyntax \end{code} Make some local @Ids@ for a template @CoreExpr@. These have bogus @@ -245,18 +273,12 @@ Make some local @Ids@ for a template @CoreExpr@. These have bogus instantiated before use. \begin{code} --- | Make a "wild Id". This is typically used when you need a binder that you don't expect to use -mkWildId :: Type -> Id -mkWildId ty = mkSysLocal (fsLit "wild") (mkBuiltinUnique 1) ty - +-- | Workers get local names. "CoreTidy" will externalise these if necessary mkWorkerId :: Unique -> Id -> Type -> Id --- | Workers get local names. CoreTidy will externalise these if necessary mkWorkerId uniq unwrkr ty - = mkLocalId wkr_name ty - where - wkr_name = mkInternalName uniq (mkWorkerOcc (getOccName unwrkr)) (getSrcSpan unwrkr) + = mkLocalId (mkDerivedInternalName mkWorkerOcc uniq (getName unwrkr)) ty --- | Create a "template local": a family of system local Ids in bijection with Ints, typically used in unfoldings +-- | Create a /template local/: a family of system local 'Id's in bijection with @Int@s, typically used in unfoldings mkTemplateLocal :: Int -> Type -> Id mkTemplateLocal i ty = mkSysLocal (fsLit "tpl") (mkBuiltinUnique i) ty @@ -266,49 +288,22 @@ mkTemplateLocals = mkTemplateLocalsNum 1 -- | Create a template local for a series of type, but start from a specified template local mkTemplateLocalsNum :: Int -> [Type] -> [Id] --- The Int gives the starting point for unique allocation mkTemplateLocalsNum n tys = zipWith mkTemplateLocal [n..] tys \end{code} %************************************************************************ %* * -\subsection[Id-general-funs]{General @Id@-related functions} -%* * -%************************************************************************ - -\begin{code} -idPrimRep :: Id -> PrimRep -idPrimRep id = typePrimRep (idType id) - -globalIdDetails :: Id -> GlobalIdDetails -globalIdDetails = globalIdVarDetails - -isId :: Id -> Bool -isId = isIdVar - -isLocalId :: Id -> Bool -isLocalId = isLocalIdVar - -isGlobalId :: Id -> Bool -isGlobalId = isGlobalIdVar - -isExportedId :: Var -> Bool -isExportedId = isExportedIdVar -\end{code} - - -%************************************************************************ -%* * \subsection{Special Ids} %* * %************************************************************************ \begin{code} +-- | If the 'Id' is that for a record selector, extract the 'sel_tycon' and label. Panic otherwise recordSelectorFieldLabel :: Id -> (TyCon, FieldLabel) recordSelectorFieldLabel id - = case globalIdDetails id of - RecordSelId { sel_tycon = tycon, sel_label = lbl } -> (tycon,lbl) + = case Var.idDetails id of + RecSelId { sel_tycon = tycon } -> (tycon, idName id) _ -> panic "recordSelectorFieldLabel" isRecordSelector :: Id -> Bool @@ -316,92 +311,95 @@ isNaughtyRecordSelector :: Id -> Bool isPrimOpId :: Id -> Bool isFCallId :: Id -> Bool isDataConWorkId :: Id -> Bool +isDFunId :: Id -> Bool isClassOpId_maybe :: Id -> Maybe Class isPrimOpId_maybe :: Id -> Maybe PrimOp isFCallId_maybe :: Id -> Maybe ForeignCall isDataConWorkId_maybe :: Id -> Maybe DataCon -isRecordSelector id = case globalIdDetails id of - RecordSelId {} -> True +isRecordSelector id = case Var.idDetails id of + RecSelId {} -> True _ -> False -isNaughtyRecordSelector id = case globalIdDetails id of - RecordSelId { sel_naughty = n } -> n +isNaughtyRecordSelector id = case Var.idDetails id of + RecSelId { sel_naughty = n } -> n _ -> False -isClassOpId_maybe id = case globalIdDetails id of +isClassOpId_maybe id = case Var.idDetails id of ClassOpId cls -> Just cls _other -> Nothing -isPrimOpId id = case globalIdDetails id of +isPrimOpId id = case Var.idDetails id of PrimOpId _ -> True _ -> False -isPrimOpId_maybe id = case globalIdDetails id of +isDFunId id = case Var.idDetails id of + DFunId {} -> True + _ -> False + +dfunNSilent :: Id -> Int +dfunNSilent id = case Var.idDetails id of + DFunId ns _ -> ns + _ -> pprTrace "dfunSilent: not a dfun:" (ppr id) 0 + +isPrimOpId_maybe id = case Var.idDetails id of PrimOpId op -> Just op _ -> Nothing -isFCallId id = case globalIdDetails id of +isFCallId id = case Var.idDetails id of FCallId _ -> True _ -> False -isFCallId_maybe id = case globalIdDetails id of +isFCallId_maybe id = case Var.idDetails id of FCallId call -> Just call _ -> Nothing -isDataConWorkId id = case globalIdDetails id of +isDataConWorkId id = case Var.idDetails id of DataConWorkId _ -> True _ -> False -isDataConWorkId_maybe id = case globalIdDetails id of +isDataConWorkId_maybe id = case Var.idDetails id of DataConWorkId con -> Just con _ -> Nothing isDataConId_maybe :: Id -> Maybe DataCon -isDataConId_maybe id = case globalIdDetails id of +isDataConId_maybe id = case Var.idDetails id of DataConWorkId con -> Just con DataConWrapId con -> Just con _ -> Nothing idDataCon :: Id -> DataCon --- ^ Get from either the worker or the wrapper to the DataCon. --- Currently used only in the desugarer. --- --- INVARIANT: @idDataCon (dataConWrapId d) = d@ +-- ^ Get from either the worker or the wrapper 'Id' to the 'DataCon'. Currently used only in the desugarer. -- --- (Remember, dataConWrapId can return either the wrapper or the worker.) -idDataCon id = isDataConId_maybe id `orElse` pprPanic "idDataCon" (ppr id - - -isDictId :: Id -> Bool -isDictId id = isDictTy (idType id) +-- INVARIANT: @idDataCon (dataConWrapId d) = d@: remember, 'dataConWrapId' can return either the wrapper or the worker +idDataCon id = isDataConId_maybe id `orElse` pprPanic "idDataCon" (ppr id) hasNoBinding :: Id -> Bool --- ^ Returns True of an Id which may not have a --- binding, even though it is defined in this module. +-- ^ Returns @True@ of an 'Id' which may not have a +-- binding, even though it is defined in this module. + -- Data constructor workers used to be things of this kind, but -- they aren't any more. Instead, we inject a binding for -- them at the CorePrep stage. -- EXCEPT: unboxed tuples, which definitely have no binding -hasNoBinding id = case globalIdDetails id of +hasNoBinding id = case Var.idDetails id of PrimOpId _ -> True -- See Note [Primop wrappers] FCallId _ -> True DataConWorkId dc -> isUnboxedTupleCon dc _ -> False isImplicitId :: Id -> Bool --- ^ isImplicitId tells whether an Id's info is implied by other +-- ^ 'isImplicitId' tells whether an 'Id's info is implied by other -- declarations, so we don't need to put its signature in an interface -- file, even if it's mentioned in some other interface unfolding. isImplicitId id - = case globalIdDetails id of - RecordSelId {} -> True - FCallId _ -> True - PrimOpId _ -> True - ClassOpId _ -> True - DataConWorkId _ -> True - DataConWrapId _ -> True + = case Var.idDetails id of + FCallId {} -> True + ClassOpId {} -> True + PrimOpId {} -> True + DataConWorkId {} -> True + DataConWrapId {} -> True -- These are are implied by their type or class decl; -- remember that all type and class decls appear in the interface file. -- The dfun id is not an implicit Id; it must *not* be omitted, because @@ -436,19 +434,39 @@ isDeadBinder bndr | isId bndr = isDeadOcc (idOccInfo bndr) \begin{code} isTickBoxOp :: Id -> Bool isTickBoxOp id = - case globalIdDetails id of + case Var.idDetails id of TickBoxOpId _ -> True _ -> False isTickBoxOp_maybe :: Id -> Maybe TickBoxOp isTickBoxOp_maybe id = - case globalIdDetails id of + case Var.idDetails id of TickBoxOpId tick -> Just tick _ -> Nothing \end{code} %************************************************************************ %* * + Evidence variables +%* * +%************************************************************************ + +\begin{code} +isEvVar :: Var -> Bool +isEvVar var = isPredTy (varType var) + +isDictId :: Id -> Bool +isDictId id = isDictTy (idType id) + +evVarPred :: EvVar -> PredType +evVarPred var + = case splitPredTy_maybe (varType var) of + Just pred -> pred + Nothing -> pprPanic "evVarPred" (ppr var <+> ppr (varType var)) +\end{code} + +%************************************************************************ +%* * \subsection{IdInfo stuff} %* * %************************************************************************ @@ -462,81 +480,68 @@ idArity id = arityInfo (idInfo id) setIdArity :: Id -> Arity -> Id setIdArity id arity = modifyIdInfo (`setArityInfo` arity) id -#ifdef OLD_STRICTNESS - --------------------------------- - -- (OLD) STRICTNESS -idStrictness :: Id -> StrictnessInfo -idStrictness id = strictnessInfo (idInfo id) - -setIdStrictness :: Id -> StrictnessInfo -> Id -setIdStrictness id strict_info = modifyIdInfo (`setStrictnessInfo` strict_info) id -#endif - -- | Returns true if an application to n args would diverge isBottomingId :: Id -> Bool -isBottomingId id = isBottomingSig (idNewStrictness id) +isBottomingId id = isBottomingSig (idStrictness id) -idNewStrictness_maybe :: Id -> Maybe StrictSig -idNewStrictness :: Id -> StrictSig +idStrictness_maybe :: Id -> Maybe StrictSig +idStrictness :: Id -> StrictSig -idNewStrictness_maybe id = newStrictnessInfo (idInfo id) -idNewStrictness id = idNewStrictness_maybe id `orElse` topSig +idStrictness_maybe id = strictnessInfo (idInfo id) +idStrictness id = idStrictness_maybe id `orElse` topSig -setIdNewStrictness :: Id -> StrictSig -> Id -setIdNewStrictness id sig = modifyIdInfo (`setNewStrictnessInfo` Just sig) id +setIdStrictness :: Id -> StrictSig -> Id +setIdStrictness id sig = modifyIdInfo (`setStrictnessInfo` Just sig) id -zapIdNewStrictness :: Id -> Id -zapIdNewStrictness id = modifyIdInfo (`setNewStrictnessInfo` Nothing) id +zapIdStrictness :: Id -> Id +zapIdStrictness id = modifyIdInfo (`setStrictnessInfo` Nothing) id --- | This predicate says whether the id has a strict demand placed on it or +-- | This predicate says whether the 'Id' has a strict demand placed on it or -- has a type such that it can always be evaluated strictly (e.g., an -- unlifted type, but see the comment for 'isStrictType'). We need to --- check separately whether has a so-called "strict type" because if --- the demand for hasn't been computed yet but has a strict --- type, we still want @isStrictId @ to be True. +-- check separately whether the 'Id' has a so-called \"strict type\" because if +-- the demand for the given @id@ hasn't been computed yet but @id@ has a strict +-- type, we still want @isStrictId id@ to be @True@. isStrictId :: Id -> Bool isStrictId id = ASSERT2( isId id, text "isStrictId: not an id: " <+> ppr id ) - (isStrictDmd (idNewDemandInfo id)) || + (isStrictDmd (idDemandInfo id)) || (isStrictType (idType id)) --------------------------------- - -- WORKER ID -idWorkerInfo :: Id -> WorkerInfo -idWorkerInfo id = workerInfo (idInfo id) - -setIdWorkerInfo :: Id -> WorkerInfo -> Id -setIdWorkerInfo id work_info = modifyIdInfo (`setWorkerInfo` work_info) id - - --------------------------------- -- UNFOLDING idUnfolding :: Id -> Unfolding -idUnfolding id = unfoldingInfo (idInfo id) +-- Do not expose the unfolding of a loop breaker! +idUnfolding id + | isNonRuleLoopBreaker (occInfo info) = NoUnfolding + | otherwise = unfoldingInfo info + where + info = idInfo id -setIdUnfolding :: Id -> Unfolding -> Id -setIdUnfolding id unfolding = modifyIdInfo (`setUnfoldingInfo` unfolding) id +realIdUnfolding :: Id -> Unfolding +-- Expose the unfolding if there is one, including for loop breakers +realIdUnfolding id = unfoldingInfo (idInfo id) -#ifdef OLD_STRICTNESS - --------------------------------- - -- (OLD) DEMAND -idDemandInfo :: Id -> Demand.Demand -idDemandInfo id = demandInfo (idInfo id) +setIdUnfoldingLazily :: Id -> Unfolding -> Id +setIdUnfoldingLazily id unfolding = modifyIdInfo (`setUnfoldingInfoLazily` unfolding) id -setIdDemandInfo :: Id -> Demand.Demand -> Id -setIdDemandInfo id demand_info = modifyIdInfo (`setDemandInfo` demand_info) id -#endif +setIdUnfolding :: Id -> Unfolding -> Id +setIdUnfolding id unfolding = modifyIdInfo (`setUnfoldingInfo` unfolding) id -idNewDemandInfo_maybe :: Id -> Maybe NewDemand.Demand -idNewDemandInfo :: Id -> NewDemand.Demand +idDemandInfo_maybe :: Id -> Maybe Demand +idDemandInfo :: Id -> Demand -idNewDemandInfo_maybe id = newDemandInfo (idInfo id) -idNewDemandInfo id = newDemandInfo (idInfo id) `orElse` NewDemand.topDmd +idDemandInfo_maybe id = demandInfo (idInfo id) +idDemandInfo id = demandInfo (idInfo id) `orElse` topDmd -setIdNewDemandInfo :: Id -> NewDemand.Demand -> Id -setIdNewDemandInfo id dmd = modifyIdInfo (`setNewDemandInfo` Just dmd) id +setIdDemandInfo :: Id -> Demand -> Id +setIdDemandInfo id dmd = modifyIdInfo (`setDemandInfo` Just dmd) id --------------------------------- -- SPECIALISATION + +-- See Note [Specialisations and RULES in IdInfo] in IdInfo.lhs + idSpecialisation :: Id -> SpecInfo idSpecialisation id = specInfo (idInfo id) @@ -552,34 +557,21 @@ setIdSpecialisation id spec_info = modifyIdInfo (`setSpecInfo` spec_info) id --------------------------------- -- CAF INFO idCafInfo :: Id -> CafInfo -#ifdef OLD_STRICTNESS -idCafInfo id = case cgInfo (idInfo id) of - NoCgInfo -> pprPanic "idCafInfo" (ppr id) - info -> cgCafInfo info -#else idCafInfo id = cafInfo (idInfo id) -#endif setIdCafInfo :: Id -> CafInfo -> Id setIdCafInfo id caf_info = modifyIdInfo (`setCafInfo` caf_info) id --------------------------------- - -- CPR INFO -#ifdef OLD_STRICTNESS -idCprInfo :: Id -> CprInfo -idCprInfo id = cprInfo (idInfo id) - -setIdCprInfo :: Id -> CprInfo -> Id -setIdCprInfo id cpr_info = modifyIdInfo (`setCprInfo` cpr_info) id -#endif - - --------------------------------- -- Occcurrence INFO idOccInfo :: Id -> OccInfo idOccInfo id = occInfo (idInfo id) setIdOccInfo :: Id -> OccInfo -> Id setIdOccInfo id occ_info = modifyIdInfo (`setOccInfo` occ_info) id + +zapIdOccInfo :: Id -> Id +zapIdOccInfo b = b `setIdOccInfo` NoOccInfo \end{code} @@ -589,14 +581,26 @@ The inline pragma tells us to be very keen to inline this Id, but it's still OK not to if optimisation is switched off. \begin{code} -idInlinePragma :: Id -> InlinePragInfo +idInlinePragma :: Id -> InlinePragma idInlinePragma id = inlinePragInfo (idInfo id) -setInlinePragma :: Id -> InlinePragInfo -> Id +setInlinePragma :: Id -> InlinePragma -> Id setInlinePragma id prag = modifyIdInfo (`setInlinePragInfo` prag) id -modifyInlinePragma :: Id -> (InlinePragInfo -> InlinePragInfo) -> Id +modifyInlinePragma :: Id -> (InlinePragma -> InlinePragma) -> Id modifyInlinePragma id fn = modifyIdInfo (\info -> info `setInlinePragInfo` (fn (inlinePragInfo info))) id + +idInlineActivation :: Id -> Activation +idInlineActivation id = inlinePragmaActivation (idInlinePragma id) + +setInlineActivation :: Id -> Activation -> Id +setInlineActivation id act = modifyInlinePragma id (\prag -> setInlinePragmaActivation prag act) + +idRuleMatchInfo :: Id -> RuleMatchInfo +idRuleMatchInfo id = inlinePragmaRuleMatchInfo (idInlinePragma id) + +isConLikeId :: Id -> Bool +isConLikeId id = isDataConWorkId id || isConLike (idRuleMatchInfo id) \end{code} @@ -606,11 +610,15 @@ modifyInlinePragma id fn = modifyIdInfo (\info -> info `setInlinePragInfo` (fn ( idLBVarInfo :: Id -> LBVarInfo idLBVarInfo id = lbvarInfo (idInfo id) +-- | Returns whether the lambda associated with the 'Id' is certainly applied at most once +-- OR we are applying the \"state hack\" which makes it appear as if theis is the case for +-- lambdas used in @IO@. You should prefer using this over 'isOneShotLambda' isOneShotBndr :: Id -> Bool -- This one is the "business end", called externally. -- Its main purpose is to encapsulate the Horrible State Hack isOneShotBndr id = isOneShotLambda id || isStateHackType (idType id) +-- | Should we apply the state hack to values of this 'Type'? isStateHackType :: Type -> Bool isStateHackType ty | opt_NoStateHack @@ -638,7 +646,8 @@ isStateHackType ty -- spot that fill_in has arity 2 (and when Keith is done, we will) but we can't yet. --- The OneShotLambda functions simply fiddle with the IdInfo flag +-- | Returns whether the lambda associated with the 'Id' is certainly applied at most once. +-- You probably want to use 'isOneShotBndr' instead isOneShotLambda :: Id -> Bool isOneShotLambda id = case idLBVarInfo id of IsOneShotLambda -> True @@ -652,6 +661,7 @@ clearOneShotLambda id | isOneShotLambda id = modifyIdInfo (`setLBVarInfo` NoLBVarInfo) id | otherwise = id +-- The OneShotLambda functions simply fiddle with the IdInfo flag -- But watch out: this may change the type of something else -- f = \x -> e -- If we change the one-shot-ness of x, f's type changes @@ -673,33 +683,73 @@ zapFragileIdInfo = zapInfo zapFragileInfo Note [transferPolyIdInfo] ~~~~~~~~~~~~~~~~~~~~~~~~~ -Suppose we have +This transfer is used in two places: + FloatOut (long-distance let-floating) + SimplUtils.abstractFloats (short-distance let-floating) + +Consider the short-distance let-floating: f = /\a. let g = rhs in ... -where g has interesting strictness information. Then if we float thus +Then if we float thus g' = /\a. rhs - f = /\a. ...[g' a/g] + f = /\a. ...[g' a/g].... + +we *do not* want to lose g's + * strictness information + * arity + * inline pragma (though that is bit more debatable) + * occurrence info + +Mostly this is just an optimisation, but it's *vital* to +transfer the occurrence info. Consider + + NonRec { f = /\a. let Rec { g* = ..g.. } in ... } -we *do not* want to lose the strictness information on g. Nor arity. +where the '*' means 'LoopBreaker'. Then if we float we must get -It's simple to retain strictness and arity, but not so simple to retain - worker info - rules + Rec { g'* = /\a. ...(g' a)... } + NonRec { f = /\a. ...[g' a/g]....} + +where g' is also marked as LoopBreaker. If not, terrible things +can happen if we re-simplify the binding (and the Simplifier does +sometimes simplify a term twice); see Trac #4345. + +It's not so simple to retain + * worker info + * rules so we simply discard those. Sooner or later this may bite us. -This transfer is used in two places: - FloatOut (long-distance let-floating) - SimplUtils.abstractFloats (short-distance let-floating) +If we abstract wrt one or more *value* binders, we must modify the +arity and strictness info before transferring it. E.g. + f = \x. e +--> + g' = \y. \x. e + + substitute (g' y) for g +Notice that g' has an arity one more than the original g \begin{code} -transferPolyIdInfo :: Id -> Id -> Id -transferPolyIdInfo old_id new_id +transferPolyIdInfo :: Id -- Original Id + -> [Var] -- Abstract wrt these variables + -> Id -- New Id + -> Id +transferPolyIdInfo old_id abstract_wrt new_id = modifyIdInfo transfer new_id where - old_info = idInfo old_id - transfer new_info = new_info `setNewStrictnessInfo` (newStrictnessInfo old_info) - `setArityInfo` (arityInfo old_info) + arity_increase = count isId abstract_wrt -- Arity increases by the + -- number of value binders + + old_info = idInfo old_id + old_arity = arityInfo old_info + old_inline_prag = inlinePragInfo old_info + old_occ_info = occInfo old_info + new_arity = old_arity + arity_increase + old_strictness = strictnessInfo old_info + new_strictness = fmap (increaseStrictSigArity arity_increase) old_strictness + + transfer new_info = new_info `setStrictnessInfo` new_strictness + `setArityInfo` new_arity + `setInlinePragInfo` old_inline_prag + `setOccInfo` old_occ_info \end{code} -