vanillaIdInfo, mkIdInfo, seqIdInfo, megaSeqIdInfo,
+ -- Zapping
+ zapFragileInfo, zapLamInfo, zapSpecPragInfo, copyIdInfo,
+
-- Flavour
IdFlavour(..), flavourInfo,
- setNoDiscardInfo, zapSpecPragInfo, copyIdInfo,
+ setNoDiscardInfo,
ppFlavourInfo,
-- Arity
demandInfo, setDemandInfo,
-- Inline prags
- InlinePragInfo(..), OccInfo(..),
- inlinePragInfo, setInlinePragInfo, notInsideLambda,
+ InlinePragInfo(..),
+ inlinePragInfo, setInlinePragInfo, pprInlinePragInfo,
+
+ -- Occurrence info
+ OccInfo(..), InsideLam, OneBranch, insideLam, notInsideLam, oneBranch, notOneBranch,
+ occInfo, setOccInfo, isFragileOccInfo,
-- Specialisation
specInfo, setSpecInfo,
-- Constructed Product Result Info
CprInfo(..), cprInfo, setCprInfo, ppCprInfo, noCprInfo,
- -- Zapping
- zapLamIdInfo, zapFragileIdInfo, zapIdInfoForStg,
-
-- Lambda-bound variable info
LBVarInfo(..), lbvarInfo, setLBVarInfo, noLBVarInfo
) where
import {-# SOURCE #-} Const ( Con )
import Var ( Id )
+import VarSet ( IdOrTyVarSet )
import FieldLabel ( FieldLabel )
import Demand ( Demand, isStrict, isLazy, wwLazy, pprDemands, seqDemand, seqDemands )
-import Type ( UsageAnn )
import Outputable
import Maybe ( isJust )
`setUnfoldingInfo`,
`setCprInfo`,
`setWorkerInfo`,
- `setCafInfo`
+ `setCafInfo`,
+ `setOccInfo`
-- infixl so you can say (id `set` a `set` b)
\end{code}
cafInfo :: CafInfo,
cprInfo :: CprInfo, -- Function always constructs a product result
lbvarInfo :: LBVarInfo, -- Info about a lambda-bound variable
- inlinePragInfo :: InlinePragInfo -- Inline pragmas
+ inlinePragInfo :: InlinePragInfo, -- Inline pragma
+ occInfo :: OccInfo -- How it occurs
}
seqIdInfo :: IdInfo -> ()
seqCaf (cafInfo info) `seq`
seqCpr (cprInfo info) `seq`
seqLBVar (lbvarInfo info) `seq`
- seqInlinePrag (inlinePragInfo info)
+ seqOccInfo (occInfo info)
\end{code}
Setters
\begin{code}
setWorkerInfo info wk = wk `seq` info { workerInfo = wk }
-setSpecInfo info sp = sp `seq` info { specInfo = sp }
+setSpecInfo info sp = PSEQ sp (info { specInfo = sp })
setInlinePragInfo info pr = pr `seq` info { inlinePragInfo = pr }
+setOccInfo info oc = oc `seq` info { occInfo = oc }
setStrictnessInfo info st = st `seq` info { strictnessInfo = st }
-- Try to avoid spack leaks by seq'ing
SpecPragmaId -> info { flavourInfo = VanillaId }
other -> info
-copyIdInfo :: IdInfo -- From
- -> IdInfo -- To
- -> IdInfo -- To updated with stuff from From; except flavour unchanged
--- copyIdInfo is used when shorting out a top-level binding
--- f_local = BIG
--- f = f_local
--- where f is exported. We are going to swizzle it around to
--- f = BIG
--- f_local = f
--- but we must be careful to combine their IdInfos right.
--- The fact that things can go wrong here is a bad sign, but I can't see
--- how to make it 'patently right', so copyIdInfo is derived (pretty much) by trial and error
---
--- Here 'from' is f_local, 'to' is f.
-
-copyIdInfo from to = from { flavourInfo = flavourInfo to,
- specInfo = specInfo to
- }
- -- It's important to propagate the inline pragmas from bndr
- -- to exportd_id. Ditto strictness etc. This "bites" when we use an INLNE pragma:
- -- {-# INLINE f #-}
- -- f x = (x,x)
- --
- -- This becomes (where the "*" means INLINE prag)
- --
- -- M.f = /\a -> let mf* = \x -> (x,x) in mf
- --
- -- Now the mf floats out and we end up with the trivial binding
- --
- -- mf* = /\a -> \x -> (x,x)
- -- M.f = mf
- --
- -- Now, when we short out the M.f = mf binding we must preserve the inline
- -- pragma on the mf binding.
- --
- -- On the other hand, transformation rules may be attached to the
- -- 'to' Id, and we want to preserve them.
\end{code}
cafInfo = MayHaveCafRefs,
cprInfo = NoCPRInfo,
lbvarInfo = NoLBVarInfo,
- inlinePragInfo = NoInlinePragInfo
+ inlinePragInfo = NoInlinePragInfo,
+ occInfo = NoOccInfo
}
\end{code}
\begin{code}
data ArityInfo
= UnknownArity -- No idea
- | ArityExactly Int -- Arity is exactly this
- | ArityAtLeast Int -- Arity is this or greater
+
+ | ArityExactly Int -- Arity is exactly this. We use this when importing a
+ -- function; it's already been compiled and we know its
+ -- arity for sure.
+
+ | ArityAtLeast Int -- Arity is this or greater. We attach this arity to
+ -- functions in the module being compiled. Their arity
+ -- might increase later in the compilation process, if
+ -- an extra lambda floats up to the binding site.
seqArity :: ArityInfo -> ()
seqArity a = arityLowerBound a `seq` ()
\begin{code}
data InlinePragInfo
= NoInlinePragInfo
+ | IMustNotBeINLINEd Bool -- True <=> came from an INLINE prag, False <=> came from a NOINLINE prag
+ (Maybe Int) -- Phase number from pragma, if any
+ -- The True, Nothing case doesn't need to be recorded
- | IMustNotBeINLINEd -- User NOINLINE pragma
-
- | IAmALoopBreaker -- Used by the occurrence analyser to mark loop-breakers
- -- in a group of recursive definitions
+instance Outputable InlinePragInfo where
+ -- This is now parsed in interface files
+ ppr NoInlinePragInfo = empty
+ ppr other_prag = ptext SLIT("__U") <> pprInlinePragInfo other_prag
+
+pprInlinePragInfo NoInlinePragInfo = empty
+pprInlinePragInfo (IMustNotBeINLINEd True Nothing) = empty
+pprInlinePragInfo (IMustNotBeINLINEd True (Just n)) = brackets (int n)
+pprInlinePragInfo (IMustNotBeINLINEd False Nothing) = brackets (char '!')
+pprInlinePragInfo (IMustNotBeINLINEd False (Just n)) = brackets (char '!' <> int n)
+
+instance Show InlinePragInfo where
+ showsPrec p prag = showsPrecSDoc p (ppr prag)
+\end{code}
- | ICanSafelyBeINLINEd -- Used by the occurrence analyser to mark things
- -- that manifesly occur once, not inside SCCs,
- -- not in constructor arguments
- OccInfo -- Says whether the occurrence is inside a lambda
- -- If so, must only substitute WHNFs
+%************************************************************************
+%* *
+\subsection{Occurrence information}
+%* *
+%************************************************************************
- Bool -- False <=> occurs in more than one case branch
- -- If so, there's a code-duplication issue
+\begin{code}
+data OccInfo
+ = NoOccInfo
| IAmDead -- Marks unused variables. Sometimes useful for
-- lambda and case-bound variables.
- | IMustBeINLINEd -- Absolutely must inline; used for PrimOps and
- -- constructors only.
+ | OneOcc InsideLam
-seqInlinePrag :: InlinePragInfo -> ()
-seqInlinePrag (ICanSafelyBeINLINEd occ alts)
- = occ `seq` alts `seq` ()
-seqInlinePrag other
- = ()
+ OneBranch
-instance Outputable InlinePragInfo where
- -- only used for debugging; never parsed. KSW 1999-07
- ppr NoInlinePragInfo = empty
- ppr IMustBeINLINEd = ptext SLIT("__UU")
- ppr IMustNotBeINLINEd = ptext SLIT("__Unot")
- ppr IAmALoopBreaker = ptext SLIT("__Ux")
- ppr IAmDead = ptext SLIT("__Ud")
- ppr (ICanSafelyBeINLINEd InsideLam _) = ptext SLIT("__Ul")
- ppr (ICanSafelyBeINLINEd _ _) = ptext SLIT("__Us")
-
-instance Show InlinePragInfo where
- showsPrec p prag = showsPrecSDoc p (ppr prag)
-\end{code}
+ | IAmALoopBreaker -- Used by the occurrence analyser to mark loop-breakers
+ -- in a group of recursive definitions
-\begin{code}
-data OccInfo
- = NotInsideLam
+seqOccInfo :: OccInfo -> ()
+seqOccInfo (OneOcc in_lam once) = in_lam `seq` once `seq` ()
+seqOccInfo occ = ()
- | InsideLam -- Inside a non-linear lambda (that is, a lambda which
- -- is sure to be instantiated only once).
+type InsideLam = Bool -- True <=> Occurs inside a non-linear lambda
-- Substituting a redex for this occurrence is
-- dangerous because it might duplicate work.
+insideLam = True
+notInsideLam = False
-instance Outputable OccInfo where
- ppr NotInsideLam = empty
- ppr InsideLam = text "l"
+type OneBranch = Bool -- True <=> Occurs in only one case branch
+ -- so no code-duplication issue to worry about
+oneBranch = True
+notOneBranch = False
+isFragileOccInfo :: OccInfo -> Bool
+isFragileOccInfo (OneOcc _ _) = True
+isFragileOccInfo other = False
+\end{code}
-notInsideLambda :: OccInfo -> Bool
-notInsideLambda NotInsideLam = True
-notInsideLambda InsideLam = False
+\begin{code}
+instance Outputable OccInfo where
+ -- only used for debugging; never parsed. KSW 1999-07
+ ppr NoOccInfo = empty
+ ppr IAmALoopBreaker = ptext SLIT("_Kx")
+ ppr IAmDead = ptext SLIT("_Kd")
+ ppr (OneOcc inside_lam one_branch) | inside_lam = ptext SLIT("_Kl")
+ | one_branch = ptext SLIT("_Ks")
+ | otherwise = ptext SLIT("_Ks*")
+
+instance Show OccInfo where
+ showsPrec p occ = showsPrecSDoc p (ppr occ)
\end{code}
%************************************************************************
noWorkerInfo = Nothing
-workerExists :: Maybe Id -> Bool
+workerExists :: WorkerInfo -> Bool
workerExists = isJust
\end{code}
%************************************************************************
%* *
-\subsection[CAF-IdInfo]{CAF-related information}
-%* *
-%************************************************************************
-
-zapFragileIdInfo is used when cloning binders, mainly in the
-simplifier. We must forget about used-once information because that
-isn't necessarily correct in the transformed program.
-Also forget specialisations and unfoldings because they would need
-substitution to be correct. (They get pinned back on separately.)
-
-\begin{code}
-zapFragileIdInfo :: IdInfo -> Maybe IdInfo
-zapFragileIdInfo info@(IdInfo {inlinePragInfo = inline_prag,
- workerInfo = wrkr,
- specInfo = rules,
- unfoldingInfo = unfolding})
- | not is_fragile_inline_prag
- -- We must forget about whether it was marked safe-to-inline,
- -- because that isn't necessarily true in the simplified expression.
- -- This is important because expressions may be re-simplified
-
- && isEmptyCoreRules rules
- -- Specialisations would need substituting. They get pinned
- -- back on separately.
-
- && not (workerExists wrkr)
-
- && not (hasUnfolding unfolding)
- -- This is very important; occasionally a let-bound binder is used
- -- as a binder in some lambda, in which case its unfolding is utterly
- -- bogus. Also the unfolding uses old binders so if we left it we'd
- -- have to substitute it. Much better simply to give the Id a new
- -- unfolding each time, which is what the simplifier does.
- = Nothing
-
- | otherwise
- = Just (info {inlinePragInfo = safe_inline_prag,
- workerInfo = noWorkerInfo,
- specInfo = emptyCoreRules,
- unfoldingInfo = noUnfolding})
-
- where
- is_fragile_inline_prag = case inline_prag of
- ICanSafelyBeINLINEd _ _ -> True
-
--- We used to say the dead-ness was fragile, but I don't
--- see why it is. Furthermore, deadness is a pain to lose;
--- see Simplify.mkDupableCont (Select ...)
--- IAmDead -> True
-
- other -> False
-
- -- Be careful not to destroy real 'pragma' info
- safe_inline_prag | is_fragile_inline_prag = NoInlinePragInfo
- | otherwise = inline_prag
-\end{code}
-
-
-@zapLamIdInfo@ is used for lambda binders that turn out to to be
-part of an unsaturated lambda
-
-\begin{code}
-zapLamIdInfo :: IdInfo -> Maybe IdInfo
-zapLamIdInfo info@(IdInfo {inlinePragInfo = inline_prag, demandInfo = demand})
- | is_safe_inline_prag && not (isStrict demand)
- = Nothing
- | otherwise
- = Just (info {inlinePragInfo = safe_inline_prag,
- demandInfo = wwLazy})
- where
- -- The "unsafe" prags are the ones that say I'm not in a lambda
- -- because that might not be true for an unsaturated lambda
- is_safe_inline_prag = case inline_prag of
- ICanSafelyBeINLINEd NotInsideLam nalts -> False
- other -> True
-
- safe_inline_prag = case inline_prag of
- ICanSafelyBeINLINEd _ nalts
- -> ICanSafelyBeINLINEd InsideLam nalts
- other -> inline_prag
-\end{code}
-
-\begin{code}
-zapIdInfoForStg :: IdInfo -> IdInfo
- -- Return only the info needed for STG stuff
- -- Namely, nothing, I think
-zapIdInfoForStg info = vanillaIdInfo
-\end{code}
-
-
-%************************************************************************
-%* *
\subsection[cpr-IdInfo]{Constructed Product Result info about an @Id@}
%* *
%************************************************************************
instance Show LBVarInfo where
showsPrec p c = showsPrecSDoc p (ppr c)
\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Bulk operations on IdInfo}
+%* *
+%************************************************************************
+
+zapFragileInfo is used when cloning binders, mainly in the
+simplifier. We must forget about used-once information because that
+isn't necessarily correct in the transformed program.
+Also forget specialisations and unfoldings because they would need
+substitution to be correct. (They get pinned back on separately.)
+
+\begin{code}
+zapFragileInfo :: IdInfo -> Maybe IdInfo
+zapFragileInfo info@(IdInfo {occInfo = occ,
+ workerInfo = wrkr,
+ specInfo = rules,
+ unfoldingInfo = unfolding})
+ | not (isFragileOccInfo occ)
+ -- We must forget about whether it was marked safe-to-inline,
+ -- because that isn't necessarily true in the simplified expression.
+ -- This is important because expressions may be re-simplified
+ -- We don't zap deadness or loop-breaker-ness.
+ -- The latter is important because it tells MkIface not to
+ -- spit out an inlining for the thing. The former doesn't
+ -- seem so important, but there's no harm.
+
+ && isEmptyCoreRules rules
+ -- Specialisations would need substituting. They get pinned
+ -- back on separately.
+
+ && not (workerExists wrkr)
+
+ && not (hasUnfolding unfolding)
+ -- This is very important; occasionally a let-bound binder is used
+ -- as a binder in some lambda, in which case its unfolding is utterly
+ -- bogus. Also the unfolding uses old binders so if we left it we'd
+ -- have to substitute it. Much better simply to give the Id a new
+ -- unfolding each time, which is what the simplifier does.
+ = Nothing
+
+ | otherwise
+ = Just (info {occInfo = robust_occ_info,
+ workerInfo = noWorkerInfo,
+ specInfo = emptyCoreRules,
+ unfoldingInfo = noUnfolding})
+ where
+ -- It's important to keep the loop-breaker info,
+ -- because the substitution doesn't remember it.
+ robust_occ_info = case occ of
+ OneOcc _ _ -> NoOccInfo
+ other -> occ
+\end{code}
+
+@zapLamInfo@ is used for lambda binders that turn out to to be
+part of an unsaturated lambda
+
+\begin{code}
+zapLamInfo :: IdInfo -> Maybe IdInfo
+zapLamInfo info@(IdInfo {occInfo = occ, demandInfo = demand})
+ | is_safe_occ && not (isStrict demand)
+ = Nothing
+ | otherwise
+ = Just (info {occInfo = safe_occ,
+ demandInfo = wwLazy})
+ where
+ -- 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 = case occ of
+ OneOcc in_lam once -> in_lam
+ other -> True
+
+ safe_occ = case occ of
+ OneOcc _ once -> OneOcc insideLam once
+ other -> occ
+\end{code}
+
+
+copyIdInfo is used when shorting out a top-level binding
+ f_local = BIG
+ f = f_local
+where f is exported. We are going to swizzle it around to
+ f = BIG
+ f_local = f
+but we must be careful to combine their IdInfos right.
+The fact that things can go wrong here is a bad sign, but I can't see
+how to make it 'patently right', so copyIdInfo is derived (pretty much) by trial and error
+
+Here 'from' is f_local, 'to' is f, and the result is attached to f
+
+\begin{code}
+copyIdInfo :: IdInfo -- From
+ -> IdInfo -- To
+ -> IdInfo -- To, updated with stuff from From; except flavour unchanged
+copyIdInfo from to = from { flavourInfo = flavourInfo to,
+ specInfo = specInfo to,
+ inlinePragInfo = inlinePragInfo to
+ }
+ -- It's important to preserve the inline pragma on 'f'; e.g. consider
+ -- {-# NOINLINE f #-}
+ -- f = local
+ --
+ -- similarly, transformation rules may be attached to f
+ -- and we want to preserve them.
+ --
+ -- On the other hand, we want the strictness info from f_local.
+\end{code}
projects / ghc-hetmet.git / blobdiff