Haskell. [WDP 94/11])
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module IdInfo (
+ -- * The GlobalIdDetails type
GlobalIdDetails(..), notGlobalId, -- Not abstract
+ -- * The IdInfo type
IdInfo, -- Abstract
vanillaIdInfo, noCafIdInfo,
seqIdInfo, megaSeqIdInfo,
- -- Zapping
+ -- ** Zapping various forms of Info
zapLamInfo, zapDemandInfo, zapFragileInfo,
- -- Arity
+ -- ** The ArityInfo type
ArityInfo,
unknownArity,
arityInfo, setArityInfo, ppArityInfo,
- -- New demand and strictness info
+ -- ** Demand and strictness Info
newStrictnessInfo, setNewStrictnessInfo,
newDemandInfo, setNewDemandInfo, pprNewStrictness,
setAllStrictnessInfo,
#ifdef OLD_STRICTNESS
- -- Strictness; imported from Demand
+ -- ** Old strictness Info
StrictnessInfo(..),
mkStrictnessInfo, noStrictnessInfo,
- ppStrictnessInfo,isBottomingStrictness,
-#endif
-
- -- Worker
- WorkerInfo(..), workerExists, wrapperArity, workerId,
- workerInfo, setWorkerInfo, ppWorkerInfo,
-
- -- Unfolding
- unfoldingInfo, setUnfoldingInfo, setUnfoldingInfoLazily,
+ ppStrictnessInfo, isBottomingStrictness,
+ strictnessInfo, setStrictnessInfo,
+
+ oldStrictnessFromNew, newStrictnessFromOld,
-#ifdef OLD_STRICTNESS
- -- Old DemandInfo and StrictnessInfo
+ -- ** Old demand Info
demandInfo, setDemandInfo,
- strictnessInfo, setStrictnessInfo,
- cprInfoFromNewStrictness,
- oldStrictnessFromNew, newStrictnessFromOld,
oldDemand, newDemand,
- -- Constructed Product Result Info
- CprInfo(..), cprInfo, setCprInfo, ppCprInfo, noCprInfo,
+ -- ** Old Constructed Product Result Info
+ CprInfo(..),
+ cprInfo, setCprInfo, ppCprInfo, noCprInfo,
+ cprInfoFromNewStrictness,
#endif
- -- Inline prags
- InlinePragInfo,
- inlinePragInfo, setInlinePragInfo,
-
- -- Occurrence info
- OccInfo(..), isFragileOcc, isDeadOcc, isLoopBreaker,
- InsideLam, OneBranch, insideLam, notInsideLam, oneBranch, notOneBranch,
- occInfo, setOccInfo,
-
- -- Specialisation
- SpecInfo(..), specInfo, setSpecInfo, isEmptySpecInfo,
- specInfoFreeVars, specInfoRules, seqSpecInfo,
-
- -- CAF info
- CafInfo(..), cafInfo, ppCafInfo, setCafInfo, mayHaveCafRefs,
+ -- ** The WorkerInfo type
+ WorkerInfo(..),
+ workerExists, wrapperArity, workerId,
+ workerInfo, setWorkerInfo, ppWorkerInfo,
- -- Lambda-bound variable info
- LBVarInfo(..), lbvarInfo, setLBVarInfo, noLBVarInfo, hasNoLBVarInfo,
+ -- ** Unfolding Info
+ unfoldingInfo, setUnfoldingInfo, setUnfoldingInfoLazily,
- -- Tick-box info
+ -- ** The InlinePragInfo type
+ InlinePragInfo,
+ inlinePragInfo, setInlinePragInfo,
+
+ -- ** The OccInfo type
+ OccInfo(..),
+ isFragileOcc, isDeadOcc, isLoopBreaker,
+ occInfo, setOccInfo,
+
+ InsideLam, OneBranch,
+ insideLam, notInsideLam, oneBranch, notOneBranch,
+
+ -- ** The SpecInfo type
+ SpecInfo(..),
+ isEmptySpecInfo, specInfoFreeVars,
+ specInfoRules, seqSpecInfo, setSpecInfoHead,
+ specInfo, setSpecInfo,
+
+ -- ** The CAFInfo type
+ CafInfo(..),
+ ppCafInfo, mayHaveCafRefs,
+ cafInfo, setCafInfo,
+
+ -- ** The LBVarInfo type
+ LBVarInfo(..),
+ noLBVarInfo, hasNoLBVarInfo,
+ lbvarInfo, setLBVarInfo,
+
+ -- ** Tick-box Info
TickBoxOp(..), TickBoxId,
) where
-#include "HsVersions.h"
+import CoreSyn ( CoreRule, setRuleIdName, seqRules, Unfolding, noUnfolding )
-import CoreSyn
import Class
import PrimOp
+import Name
import Var
import VarSet
import BasicTypes
import NewDemand
import Outputable
import Module
+import FastString
import Data.Maybe
#ifdef OLD_STRICTNESS
-import Name
import Demand
import qualified Demand
import Util
To be removed later
\begin{code}
--- setAllStrictnessInfo :: IdInfo -> Maybe StrictSig -> IdInfo
--- Set old and new strictness info
+-- | Set old and new strictness information together
+setAllStrictnessInfo :: IdInfo -> Maybe StrictSig -> IdInfo
setAllStrictnessInfo info Nothing
= info { newStrictnessInfo = Nothing
#ifdef OLD_STRICTNESS
#endif
}
+seqNewStrictnessInfo :: Maybe StrictSig -> ()
seqNewStrictnessInfo Nothing = ()
seqNewStrictnessInfo (Just ty) = seqStrictSig ty
+pprNewStrictness :: Maybe StrictSig -> SDoc
pprNewStrictness Nothing = empty
-pprNewStrictness (Just sig) = ftext FSLIT("Str:") <+> ppr sig
+pprNewStrictness (Just sig) = ftext (fsLit "Str:") <+> ppr sig
#ifdef OLD_STRICTNESS
oldStrictnessFromNew :: StrictSig -> Demand.StrictnessInfo
\begin{code}
+seqNewDemandInfo :: Maybe Demand -> ()
seqNewDemandInfo Nothing = ()
seqNewDemandInfo (Just dmd) = seqDemand dmd
\end{code}
(recursively) by Var.lhs.
\begin{code}
+-- | Information pertaining to global 'Id's. See "Var#globalvslocal" for the distinction
+-- between global and local in this context
data GlobalIdDetails
- = VanillaGlobal -- Imported from elsewhere, a default method Id.
+ = VanillaGlobal -- ^ The 'Id' is imported from elsewhere or is a default method 'Id'
- | RecordSelId -- The Id for a record selector
- { sel_tycon :: TyCon -- For a data type family, this is the *instance* TyCon
- -- not the family TyCon
+ -- | The 'Id' for a record selector
+ | RecordSelId
+ { sel_tycon :: TyCon -- ^ For a data type family, this is the /instance/ 'TyCon'
+ -- not the family 'TyCon'
, sel_label :: FieldLabel
- , sel_naughty :: Bool -- True <=> naughty
- } -- See Note [Naughty record selectors]
+ , sel_naughty :: Bool -- True <=> a "naughty" selector which can't actually exist, for example @x@ in:
+ --
+ -- > data T = forall a. MkT { x :: a }
+ }
+ -- See Note [Naughty record selectors]
-- with MkId.mkRecordSelectorId
- | DataConWorkId DataCon -- The Id for a data constructor *worker*
- | DataConWrapId DataCon -- The Id for a data constructor *wrapper*
+ | DataConWorkId DataCon -- ^ The 'Id' is for a data constructor /worker/
+ | DataConWrapId DataCon -- ^ The 'Id' is for a data constructor /wrapper/
+
-- [the only reasons we need to know is so that
-- a) to support isImplicitId
-- b) when desugaring a RecordCon we can get
-- from the Id back to the data con]
- | ClassOpId Class -- An operation of a class
+ | ClassOpId Class -- ^ The 'Id' is an operation of a class
- | PrimOpId PrimOp -- The Id for a primitive operator
- | FCallId ForeignCall -- The Id for a foreign call
+ | PrimOpId PrimOp -- ^ The 'Id' is for a primitive operator
+ | FCallId ForeignCall -- ^ The 'Id' is for a foreign call
- | TickBoxOpId TickBoxOp -- The Id for a tick box (both traditional and binary)
+ | TickBoxOpId TickBoxOp -- ^ The 'Id' is for a HPC tick box (both traditional and binary)
- | NotGlobalId -- Used as a convenient extra return value from globalIdDetails
-
+ | NotGlobalId -- ^ Used as a convenient extra return value from 'globalIdDetails'
+
+-- | An entirely unhelpful 'GlobalIdDetails'
+notGlobalId :: GlobalIdDetails
notGlobalId = NotGlobalId
instance Outputable GlobalIdDetails where
- ppr NotGlobalId = ptext SLIT("[***NotGlobalId***]")
- ppr VanillaGlobal = ptext SLIT("[GlobalId]")
- ppr (DataConWorkId _) = ptext SLIT("[DataCon]")
- ppr (DataConWrapId _) = ptext SLIT("[DataConWrapper]")
- ppr (ClassOpId _) = ptext SLIT("[ClassOp]")
- ppr (PrimOpId _) = ptext SLIT("[PrimOp]")
- ppr (FCallId _) = ptext SLIT("[ForeignCall]")
- ppr (TickBoxOpId _) = ptext SLIT("[TickBoxOp]")
- ppr (RecordSelId {}) = ptext SLIT("[RecSel]")
+ ppr NotGlobalId = ptext (sLit "[***NotGlobalId***]")
+ ppr VanillaGlobal = ptext (sLit "[GlobalId]")
+ ppr (DataConWorkId _) = ptext (sLit "[DataCon]")
+ ppr (DataConWrapId _) = ptext (sLit "[DataConWrapper]")
+ ppr (ClassOpId _) = ptext (sLit "[ClassOp]")
+ ppr (PrimOpId _) = ptext (sLit "[PrimOp]")
+ ppr (FCallId _) = ptext (sLit "[ForeignCall]")
+ ppr (TickBoxOpId _) = ptext (sLit "[TickBoxOp]")
+ ppr (RecordSelId {}) = ptext (sLit "[RecSel]")
\end{code}
%* *
%************************************************************************
-An @IdInfo@ gives {\em optional} information about an @Id@. If
-present it never lies, but it may not be present, in which case there
-is always a conservative assumption which can be made.
-
-Two @Id@s may have different info even though they have the same
-@Unique@ (and are hence the same @Id@); for example, one might lack
-the properties attached to the other.
-
-The @IdInfo@ gives information about the value, or definition, of the
-@Id@. It does {\em not} contain information about the @Id@'s usage
-(except for @DemandInfo@? ToDo). (@lbvarInfo@ is also a marginal
-case. KSW 1999-04).
-
\begin{code}
+-- | An 'IdInfo' gives /optional/ information about an 'Id'. If
+-- present it never lies, but it may not be present, in which case there
+-- is always a conservative assumption which can be made.
+--
+-- Two 'Id's may have different info even though they have the same
+-- 'Unique' (and are hence the same 'Id'); for example, one might lack
+-- the properties attached to the other.
+--
+-- The 'IdInfo' gives information about the value, or definition, of the
+-- 'Id'. It does not contain information about the 'Id''s usage,
+-- except for 'demandInfo' and 'lbvarInfo'.
data IdInfo
= IdInfo {
- arityInfo :: !ArityInfo, -- Its arity
- specInfo :: SpecInfo, -- Specialisations of this function which exist
+ arityInfo :: !ArityInfo, -- ^ 'Id' arity
+ specInfo :: SpecInfo, -- ^ Specialisations of the 'Id's function which exist
#ifdef OLD_STRICTNESS
- cprInfo :: CprInfo, -- Function always constructs a product result
- demandInfo :: Demand.Demand, -- Whether or not it is definitely demanded
- strictnessInfo :: StrictnessInfo, -- Strictness properties
+ cprInfo :: CprInfo, -- ^ If the 'Id's function always constructs a product result
+ demandInfo :: Demand.Demand, -- ^ Whether or not the 'Id' is definitely demanded
+ strictnessInfo :: StrictnessInfo, -- ^ 'Id' strictness properties
#endif
- workerInfo :: WorkerInfo, -- Pointer to Worker Function
+ workerInfo :: WorkerInfo, -- ^ Pointer to worker function.
-- Within one module this is irrelevant; the
- -- inlining of a worker is handled via the Unfolding
- -- WorkerInfo is used *only* to indicate the form of
+ -- inlining of a worker is handled via the 'Unfolding'.
+ -- However, when the module is imported by others, the
+ -- 'WorkerInfo' is used /only/ to indicate the form of
-- the RHS, so that interface files don't actually
-- need to contain the RHS; it can be derived from
-- the strictness info
- unfoldingInfo :: Unfolding, -- Its unfolding
- cafInfo :: CafInfo, -- CAF info
- lbvarInfo :: LBVarInfo, -- Info about a lambda-bound variable
- inlinePragInfo :: InlinePragInfo, -- Inline pragma
- occInfo :: OccInfo, -- How it occurs
+ unfoldingInfo :: Unfolding, -- ^ The 'Id's unfolding
+ cafInfo :: CafInfo, -- ^ 'Id' CAF info
+ lbvarInfo :: LBVarInfo, -- ^ Info about a lambda-bound variable, if the 'Id' is one
+ inlinePragInfo :: InlinePragInfo, -- ^ Any inline pragma atached to the 'Id'
+ occInfo :: OccInfo, -- ^ How the 'Id' occurs in the program
- newStrictnessInfo :: Maybe StrictSig, -- Reason for Maybe: the DmdAnal phase needs to
- -- know whether whether this is the first visit,
- -- so it can assign botSig. Other customers want
- -- topSig. So Nothing is good.
+ newStrictnessInfo :: Maybe StrictSig, -- ^ Id strictness information. Reason for Maybe:
+ -- the DmdAnal phase needs to know whether
+ -- this is the first visit, so it can assign botSig.
+ -- Other customers want topSig. So @Nothing@ is good.
- newDemandInfo :: Maybe Demand -- Similarly we want to know if there's no
- -- known demand yet, for when we are looking for
- -- CPR info
+ newDemandInfo :: Maybe Demand -- ^ Id demand information. Similarly we want to know
+ -- if there's no known demand yet, for when we are looking
+ -- for CPR info
}
+-- | Just evaluate the 'IdInfo' to WHNF
seqIdInfo :: IdInfo -> ()
seqIdInfo (IdInfo {}) = ()
+-- | Evaluate all the fields of the 'IdInfo' that are generally demanded by the
+-- compiler
megaSeqIdInfo :: IdInfo -> ()
megaSeqIdInfo info
= seqSpecInfo (specInfo info) `seq`
Setters
\begin{code}
+setWorkerInfo :: IdInfo -> WorkerInfo -> IdInfo
setWorkerInfo info wk = wk `seq` info { workerInfo = wk }
+setSpecInfo :: IdInfo -> SpecInfo -> IdInfo
setSpecInfo info sp = sp `seq` info { specInfo = sp }
+setInlinePragInfo :: IdInfo -> InlinePragInfo -> IdInfo
setInlinePragInfo info pr = pr `seq` info { inlinePragInfo = pr }
+setOccInfo :: IdInfo -> OccInfo -> IdInfo
setOccInfo info oc = oc `seq` info { occInfo = oc }
#ifdef OLD_STRICTNESS
setStrictnessInfo info st = st `seq` info { strictnessInfo = st }
#endif
-- Try to avoid spack leaks by seq'ing
+setUnfoldingInfoLazily :: IdInfo -> Unfolding -> IdInfo
setUnfoldingInfoLazily info uf -- Lazy variant to avoid looking at the
= -- unfolding of an imported Id unless necessary
info { unfoldingInfo = uf } -- (In this case the demand-zapping is redundant.)
+setUnfoldingInfo :: IdInfo -> Unfolding -> IdInfo
setUnfoldingInfo info uf
-- We do *not* seq on the unfolding info, For some reason, doing so
-- actually increases residency significantly.
setCprInfo info cp = info { cprInfo = cp }
#endif
+setArityInfo :: IdInfo -> ArityInfo -> IdInfo
setArityInfo info ar = info { arityInfo = ar }
+setCafInfo :: IdInfo -> CafInfo -> IdInfo
setCafInfo info caf = info { cafInfo = caf }
+setLBVarInfo :: IdInfo -> LBVarInfo -> IdInfo
setLBVarInfo info lb = {-lb `seq`-} info { lbvarInfo = lb }
+setNewDemandInfo :: IdInfo -> Maybe Demand -> IdInfo
setNewDemandInfo info dd = dd `seq` info { newDemandInfo = dd }
+setNewStrictnessInfo :: IdInfo -> Maybe StrictSig -> IdInfo
setNewStrictnessInfo info dd = dd `seq` info { newStrictnessInfo = dd }
\end{code}
\begin{code}
+-- | Basic 'IdInfo' that carries no useful information whatsoever
vanillaIdInfo :: IdInfo
vanillaIdInfo
= IdInfo {
newStrictnessInfo = Nothing
}
+-- | More informative 'IdInfo' we can use when we know the 'Id' has no CAF references
+noCafIdInfo :: IdInfo
noCafIdInfo = vanillaIdInfo `setCafInfo` NoCafRefs
-- Used for built-in type Ids in MkId.
\end{code}
besides the code-generator need arity info!)
\begin{code}
+-- | An 'ArityInfo' of @n@ tells us that partial application of this
+-- 'Id' to up to @n-1@ value arguments does essentially no work.
+--
+-- That is not necessarily the same as saying that it has @n@ leading
+-- lambdas, because coerces may get in the way.
+--
+-- The arity might increase later in the compilation process, if
+-- an extra lambda floats up to the binding site.
type ArityInfo = Arity
- -- A partial application of this Id to up to n-1 value arguments
- -- does essentially no work. That is not necessarily the
- -- same as saying that it has n leading lambdas, because coerces
- -- may get in the way.
-
- -- The arity might increase later in the compilation process, if
- -- an extra lambda floats up to the binding site.
+-- | It is always safe to assume that an 'Id' has an arity of 0
+unknownArity :: Arity
unknownArity = 0 :: Arity
+ppArityInfo :: Int -> SDoc
ppArityInfo 0 = empty
-ppArityInfo n = hsep [ptext SLIT("Arity"), int n]
+ppArityInfo n = hsep [ptext (sLit "Arity"), int n]
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
+-- | Tells when the inlining is active.
+-- When it is active the thing may be inlined, depending on how
+-- big it is.
+--
+-- If there was an @INLINE@ pragma, then as a separate matter, the
+-- RHS will have been made to look small with a Core inline 'Note'
+--
+-- The default 'InlinePragInfo' is 'AlwaysActive', so the info serves
+-- entirely as a way to inhibit inlining until we want it
type InlinePragInfo = Activation
- -- Tells when the inlining is active
- -- When it is active the thing may be inlined, depending on how
- -- big it is.
- --
- -- If there was an INLINE pragma, then as a separate matter, the
- -- RHS will have been made to look small with a CoreSyn Inline Note
-
- -- The default InlinePragInfo is AlwaysActive, so the info serves
- -- entirely as a way to inhibit inlining until we want it
\end{code}
%************************************************************************
\begin{code}
+-- | Records the specializations of this 'Id' that we know about
+-- in the form of rewrite 'CoreRule's that target them
data SpecInfo
= SpecInfo
[CoreRule]
- VarSet -- Locally-defined free vars of *both* LHS and RHS of rules
- -- Note [Rule dependency info]
+ VarSet -- Locally-defined free vars of *both* LHS and RHS
+ -- of rules. I don't think it needs to include the
+ -- ru_fn though.
+ -- Note [Rule dependency info] in OccurAnal
+-- | Assume that no specilizations exist: always safe
emptySpecInfo :: SpecInfo
emptySpecInfo = SpecInfo [] emptyVarSet
isEmptySpecInfo :: SpecInfo -> Bool
isEmptySpecInfo (SpecInfo rs _) = null rs
+-- | Retrieve the locally-defined free variables of both the left and
+-- right hand sides of the specialization rules
specInfoFreeVars :: SpecInfo -> VarSet
specInfoFreeVars (SpecInfo _ fvs) = fvs
specInfoRules :: SpecInfo -> [CoreRule]
specInfoRules (SpecInfo rules _) = rules
+-- | Change the name of the function the rule is keyed on on all of the 'CoreRule's
+setSpecInfoHead :: Name -> SpecInfo -> SpecInfo
+setSpecInfoHead fn (SpecInfo rules fvs)
+ = SpecInfo (map (setRuleIdName fn) rules) fvs
+
+seqSpecInfo :: SpecInfo -> ()
seqSpecInfo (SpecInfo rules fvs) = seqRules rules `seq` seqVarSet fvs
\end{code}
-Note [Rule dependency info]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
-THe VarSet in a SpecInfo is used for dependency analysis in the
-occurrence analyser. We must track free vars in *both* lhs and rhs. Why both?
-Consider
- x = y
- RULE f x = 4
-Then if we substitute y for x, we'd better do so in the
- rule's LHS too, so we'd better ensure the dependency is respsected
-
-
-
%************************************************************************
%* *
\subsection[worker-IdInfo]{Worker info about an @Id@}
%* *
%************************************************************************
-If this Id has a worker then we store a reference to it. Worker
-functions are generated by the worker/wrapper pass. This uses
-information from strictness analysis.
-
There might not be a worker, even for a strict function, because:
(a) the function might be small enough to inline, so no need
for w/w split
\begin{code}
-data WorkerInfo = NoWorker
- | HasWorker Id Arity
- -- The Arity is the arity of the *wrapper* at the moment of the
- -- w/w split. See notes above.
+-- | If this Id has a worker then we store a reference to it. Worker
+-- functions are generated by the worker\/wrapper pass, using information
+-- information from strictness analysis.
+data WorkerInfo = NoWorker -- ^ No known worker function
+ | HasWorker Id Arity -- ^ The 'Arity' is the arity of the /wrapper/ at the moment of the
+ -- worker\/wrapper split, which may be different from the current 'Id' 'Aritiy'
seqWorker :: WorkerInfo -> ()
seqWorker (HasWorker id a) = id `seq` a `seq` ()
seqWorker NoWorker = ()
+ppWorkerInfo :: WorkerInfo -> SDoc
ppWorkerInfo NoWorker = empty
-ppWorkerInfo (HasWorker wk_id _) = ptext SLIT("Worker") <+> ppr wk_id
+ppWorkerInfo (HasWorker wk_id _) = ptext (sLit "Worker") <+> ppr wk_id
workerExists :: WorkerInfo -> Bool
workerExists NoWorker = False
workerExists (HasWorker _ _) = True
+-- | The 'Id' of the worker function if it exists, or a panic otherwise
workerId :: WorkerInfo -> Id
workerId (HasWorker id _) = id
+workerId NoWorker = panic "workerId: NoWorker"
+-- | The 'Arity' of the worker function at the time of the split if it exists, or a panic otherwise
wrapperArity :: WorkerInfo -> Arity
wrapperArity (HasWorker _ a) = a
+wrapperArity NoWorker = panic "wrapperArity: NoWorker"
\end{code}
\begin{code}
-- CafInfo is used to build Static Reference Tables (see simplStg/SRT.lhs).
+-- | Records whether an 'Id' makes Constant Applicative Form references
data CafInfo
- = MayHaveCafRefs -- either:
- -- (1) A function or static constructor
- -- that refers to one or more CAFs,
- -- (2) A real live CAF
-
- | NoCafRefs -- A function or static constructor
+ = MayHaveCafRefs -- ^ Indicates that the 'Id' is for either:
+ --
+ -- 1. A function or static constructor
+ -- that refers to one or more CAFs, or
+ --
+ -- 2. A real live CAF
+
+ | NoCafRefs -- ^ A function or static constructor
-- that refers to no CAFs.
+ deriving (Eq, Ord)
-vanillaCafInfo = MayHaveCafRefs -- Definitely safe
+-- | Assumes that the 'Id' has CAF references: definitely safe
+vanillaCafInfo :: CafInfo
+vanillaCafInfo = MayHaveCafRefs
+mayHaveCafRefs :: CafInfo -> Bool
mayHaveCafRefs MayHaveCafRefs = True
mayHaveCafRefs _ = False
+seqCaf :: CafInfo -> ()
seqCaf c = c `seq` ()
-ppCafInfo NoCafRefs = ptext SLIT("NoCafRefs")
+ppCafInfo :: CafInfo -> SDoc
+ppCafInfo NoCafRefs = ptext (sLit "NoCafRefs")
ppCafInfo MayHaveCafRefs = empty
\end{code}
%* *
%************************************************************************
-If the @Id@ is a function then it may have CPR info. A CPR analysis
-phase detects whether:
-
-\begin{enumerate}
-\item
-The function's return value has a product type, i.e. an algebraic type
-with a single constructor. Examples of such types are tuples and boxed
-primitive values.
-\item
-The function always 'constructs' the value that it is returning. It
-must do this on every path through, and it's OK if it calls another
-function which constructs the result.
-\end{enumerate}
-
-If this is the case then we store a template which tells us the
-function has the CPR property and which components of the result are
-also CPRs.
-
\begin{code}
#ifdef OLD_STRICTNESS
+-- | If the @Id@ is a function then it may have Constructed Product Result
+-- (CPR) info. A CPR analysis phase detects whether:
+--
+-- 1. The function's return value has a product type, i.e. an algebraic type
+-- with a single constructor. Examples of such types are tuples and boxed
+-- primitive values.
+--
+-- 2. The function always 'constructs' the value that it is returning. It
+-- must do this on every path through, and it's OK if it calls another
+-- function which constructs the result.
+--
+-- If this is the case then we store a template which tells us the
+-- function has the CPR property and which components of the result are
+-- also CPRs.
data CprInfo
- = NoCPRInfo
- | ReturnsCPR -- Yes, this function returns a constructed product
+ = NoCPRInfo -- ^ No, this function does not return a constructed product
+ | ReturnsCPR -- ^ Yes, this function returns a constructed product
+
-- Implicitly, this means "after the function has been applied
- -- to all its arguments", so the worker/wrapper builder in
+ -- to all its arguments", so the worker\/wrapper builder in
-- WwLib.mkWWcpr checks that that it is indeed saturated before
-- making use of the CPR info
-- We used to keep nested info about sub-components, but
-- we never used it so I threw it away
+-- | It's always safe to assume that an 'Id' does not have the CPR property
+noCprInfo :: CprInt
+noCprInfo = NoCPRInfo
+
seqCpr :: CprInfo -> ()
seqCpr ReturnsCPR = ()
seqCpr NoCPRInfo = ()
-noCprInfo = NoCPRInfo
-
ppCprInfo NoCPRInfo = empty
-ppCprInfo ReturnsCPR = ptext SLIT("__M")
+ppCprInfo ReturnsCPR = ptext (sLit "__M")
instance Outputable CprInfo where
ppr = ppCprInfo
#endif
\end{code}
-
%************************************************************************
%* *
\subsection[lbvar-IdInfo]{Lambda-bound var info about an @Id@}
%* *
%************************************************************************
-If the @Id@ is a lambda-bound variable then it may have lambda-bound
-var info. Sometimes we know whether the lambda binding this var is a
-``one-shot'' lambda; that is, whether it is applied at most once.
-
-This information may be useful in optimisation, as computations may
-safely be floated inside such a lambda without risk of duplicating
-work.
-
\begin{code}
-data LBVarInfo = NoLBVarInfo
- | IsOneShotLambda -- The lambda is applied at most once).
-
-seqLBVar l = l `seq` ()
-\end{code}
+-- | If the 'Id' is a lambda-bound variable then it may have lambda-bound
+-- variable info. Sometimes we know whether the lambda binding this variable
+-- is a \"one-shot\" lambda; that is, whether it is applied at most once.
+--
+-- This information may be useful in optimisation, as computations may
+-- safely be floated inside such a lambda without risk of duplicating
+-- work.
+data LBVarInfo = NoLBVarInfo -- ^ No information
+ | IsOneShotLambda -- ^ The lambda is applied at most once).
+
+-- | It is always safe to assume that an 'Id' has no lambda-bound variable information
+noLBVarInfo :: LBVarInfo
+noLBVarInfo = NoLBVarInfo
-\begin{code}
+hasNoLBVarInfo :: LBVarInfo -> Bool
hasNoLBVarInfo NoLBVarInfo = True
hasNoLBVarInfo IsOneShotLambda = False
-noLBVarInfo = NoLBVarInfo
+seqLBVar :: LBVarInfo -> ()
+seqLBVar l = l `seq` ()
+pprLBVarInfo :: LBVarInfo -> SDoc
pprLBVarInfo NoLBVarInfo = empty
-pprLBVarInfo IsOneShotLambda = ptext SLIT("OneShot")
+pprLBVarInfo IsOneShotLambda = ptext (sLit "OneShot")
instance Outputable LBVarInfo where
ppr = pprLBVarInfo
%* *
%************************************************************************
-@zapLamInfo@ is used for lambda binders that turn out to to be
-part of an unsaturated lambda
-
\begin{code}
+-- | This is used to remove information on lambda binders that we have
+-- setup as part of a lambda group, assuming they will be applied all at once,
+-- but turn out to be part of an unsaturated lambda as in e.g:
+--
+-- > (\x1. \x2. e) arg1
zapLamInfo :: IdInfo -> Maybe IdInfo
zapLamInfo info@(IdInfo {occInfo = occ, newDemandInfo = demand})
| is_safe_occ occ && is_safe_dmd demand
-- The "unsafe" occ info is the ones that say I'm not in a lambda
-- because that might not be true for an unsaturated lambda
is_safe_occ (OneOcc in_lam _ _) = in_lam
- is_safe_occ other = True
+ is_safe_occ _other = True
safe_occ = case occ of
OneOcc _ once int_cxt -> OneOcc insideLam once int_cxt
- other -> occ
+ _other -> occ
is_safe_dmd Nothing = True
is_safe_dmd (Just dmd) = not (isStrictDmd dmd)
\end{code}
\begin{code}
+-- | Remove demand info on the 'IdInfo' if it is present, otherwise return @Nothing@
zapDemandInfo :: IdInfo -> Maybe IdInfo
zapDemandInfo info@(IdInfo {newDemandInfo = dmd})
| isJust dmd = Just (info {newDemandInfo = Nothing})
\begin{code}
zapFragileInfo :: IdInfo -> Maybe IdInfo
--- Zap info that depends on free variables
-zapFragileInfo info = Just (info `setSpecInfo` emptySpecInfo
- `setWorkerInfo` NoWorker
- `setUnfoldingInfo` NoUnfolding)
+-- ^ Zap info that depends on free variables
+zapFragileInfo info
+ = Just (info `setSpecInfo` emptySpecInfo
+ `setWorkerInfo` NoWorker
+ `setUnfoldingInfo` noUnfolding
+ `setOccInfo` if isFragileOcc occ then NoOccInfo else occ)
+ where
+ occ = occInfo info
\end{code}
%************************************************************************
\begin{code}
type TickBoxId = Int
+-- | Tick box for Hpc-style coverage
data TickBoxOp
= TickBox Module {-# UNPACK #-} !TickBoxId
- -- ^Tick box for Hpc-style coverage
instance Outputable TickBoxOp where
- ppr (TickBox mod n) = ptext SLIT("tick") <+> ppr (mod,n)
+ ppr (TickBox mod n) = ptext (sLit "tick") <+> ppr (mod,n)
\end{code}
projects / ghc-hetmet.git / blobdiff