cprInfoFromNewStrictness,
#endif
+ -- ** The WorkerInfo type
+ WorkerInfo(..),
+ workerExists, wrapperArity, workerId,
+ workerInfo, setWorkerInfo, ppWorkerInfo,
+
-- ** Unfolding Info
unfoldingInfo, setUnfoldingInfo, setUnfoldingInfoLazily,
import Class
import PrimOp
import Name
+import Var
import VarSet
import BasicTypes
import DataCon
`setArityInfo`,
`setInlinePragInfo`,
`setUnfoldingInfo`,
+ `setWorkerInfo`,
`setLBVarInfo`,
`setOccInfo`,
`setCafInfo`,
demandInfo :: Demand.Demand, -- ^ Whether or not the 'Id' is definitely demanded
strictnessInfo :: StrictnessInfo, -- ^ 'Id' strictness properties
#endif
+ workerInfo :: WorkerInfo, -- ^ Pointer to worker function.
+ -- Within one module this is irrelevant; the
+ -- 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, -- ^ The 'Id's unfolding
cafInfo :: CafInfo, -- ^ 'Id' CAF info
lbvarInfo :: LBVarInfo, -- ^ Info about a lambda-bound variable, if the 'Id' is one
megaSeqIdInfo :: IdInfo -> ()
megaSeqIdInfo info
= seqSpecInfo (specInfo info) `seq`
+ seqWorker (workerInfo info) `seq`
-- Omitting this improves runtimes a little, presumably because
-- some unfoldings are not calculated at all
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
strictnessInfo = NoStrictnessInfo,
#endif
specInfo = emptySpecInfo,
+ workerInfo = NoWorker,
unfoldingInfo = noUnfolding,
lbvarInfo = NoLBVarInfo,
inlinePragInfo = AlwaysActive,
%************************************************************************
%* *
+\subsection[worker-IdInfo]{Worker info about an @Id@}
+%* *
+%************************************************************************
+
+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
+(b) the strictness info might be "SSS" or something, so no w/w split.
+
+Sometimes the arity of a wrapper changes from the original arity from
+which it was generated, so we always emit the "original" arity into
+the interface file, as part of the worker info.
+
+How can this happen? Sometimes we get
+ f = coerce t (\x y -> $wf x y)
+at the moment of w/w split; but the eta reducer turns it into
+ f = coerce t $wf
+which is perfectly fine except that the exposed arity so far as
+the code generator is concerned (zero) differs from the arity
+when we did the split (2).
+
+All this arises because we use 'arity' to mean "exactly how many
+top level lambdas are there" in interface files; but during the
+compilation of this module it means "how many things can I apply
+this to".
+
+\begin{code}
+
+-- | 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
+
+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}
+
+
+%************************************************************************
+%* *
\subsection[CG-IdInfo]{Code generator-related information}
%* *
%************************************************************************
-- ^ 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
projects / ghc-hetmet.git / blobdiff