X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FbasicTypes%2FIdInfo.lhs;h=88d0f3dd779f6a767991e7f0feb8b119b66095af;hb=36d22a1cb608e8572776ab6d402fd0c1a9287dc5;hp=fdaef1a23223d728f7bd59e1391ec8493eb68f71;hpb=8c1b6bd7ffb9ce97da7a72f9e102998df19b23a2;p=ghc-hetmet.git diff --git a/ghc/compiler/basicTypes/IdInfo.lhs b/ghc/compiler/basicTypes/IdInfo.lhs index fdaef1a..88d0f3d 100644 --- a/ghc/compiler/basicTypes/IdInfo.lhs +++ b/ghc/compiler/basicTypes/IdInfo.lhs @@ -11,12 +11,11 @@ module IdInfo ( GlobalIdDetails(..), notGlobalId, -- Not abstract IdInfo, -- Abstract - vanillaIdInfo, noCafIdInfo, hasCafIdInfo, + vanillaIdInfo, noCafIdInfo, seqIdInfo, megaSeqIdInfo, -- Zapping zapLamInfo, zapDemandInfo, - shortableIdInfo, copyIdInfo, -- Arity ArityInfo, @@ -26,19 +25,21 @@ module IdInfo ( -- New demand and strictness info newStrictnessInfo, setNewStrictnessInfo, newDemandInfo, setNewDemandInfo, pprNewStrictness, + setAllStrictnessInfo, +#ifdef OLD_STRICTNESS -- Strictness; imported from Demand StrictnessInfo(..), mkStrictnessInfo, noStrictnessInfo, ppStrictnessInfo,isBottomingStrictness, - setAllStrictnessInfo, +#endif -- Worker WorkerInfo(..), workerExists, wrapperArity, workerId, workerInfo, setWorkerInfo, ppWorkerInfo, -- Unfolding - unfoldingInfo, setUnfoldingInfo, + unfoldingInfo, setUnfoldingInfo, setUnfoldingInfoLazily, #ifdef OLD_STRICTNESS -- Old DemandInfo and StrictnessInfo @@ -64,13 +65,8 @@ module IdInfo ( -- Specialisation specInfo, setSpecInfo, - -- CG info - CgInfo(..), cgInfo, setCgInfo, pprCgInfo, - cgCafInfo, vanillaCgInfo, - CgInfoEnv, lookupCgInfo, - -- CAF info - CafInfo(..), ppCafInfo, setCafInfo, mayHaveCafRefs, + CafInfo(..), cafInfo, ppCafInfo, setCafInfo, mayHaveCafRefs, -- Lambda-bound variable info LBVarInfo(..), lbvarInfo, setLBVarInfo, noLBVarInfo, hasNoLBVarInfo @@ -80,10 +76,8 @@ module IdInfo ( import CoreSyn -import Type ( Type, usOnce, eqUsage ) +import Class ( Class ) import PrimOp ( PrimOp ) -import NameEnv ( NameEnv, lookupNameEnv ) -import Name ( Name ) import Var ( Id ) import BasicTypes ( OccInfo(..), isFragileOcc, isDeadOcc, seqOccInfo, isLoopBreaker, InsideLam, insideLam, notInsideLam, @@ -92,15 +86,16 @@ import BasicTypes ( OccInfo(..), isFragileOcc, isDeadOcc, seqOccInfo, isLoopBrea Activation(..) ) import DataCon ( DataCon ) +import TyCon ( TyCon, FieldLabel ) import ForeignCall ( ForeignCall ) -import FieldLabel ( FieldLabel ) -import Type ( usOnce ) -import Demand hiding( Demand, seqDemand ) -import qualified Demand import NewDemand import Outputable import Maybe ( isJust ) + #ifdef OLD_STRICTNESS +import Name ( Name ) +import Demand hiding( Demand, seqDemand ) +import qualified Demand import Util ( listLengthCmp ) import List ( replicate ) #endif @@ -113,7 +108,6 @@ infixl 1 `setSpecInfo`, `setWorkerInfo`, `setLBVarInfo`, `setOccInfo`, - `setCgInfo`, `setCafInfo`, `setNewStrictnessInfo`, `setAllStrictnessInfo`, @@ -235,14 +229,17 @@ an IdInfo.hi-boot, but no Id.hi-boot, and GlobalIdDetails is imported data GlobalIdDetails = VanillaGlobal -- Imported from elsewhere, a default method Id. - | RecordSelId FieldLabel -- The Id for a record selector - | DataConId DataCon -- The Id for a data constructor *worker* + | RecordSelId TyCon FieldLabel -- The Id for a record selector + + | DataConWorkId DataCon -- The Id for a data constructor *worker* | DataConWrapId DataCon -- The Id for a data constructor *wrapper* -- [the only reasons we need to know is so that -- a) we can suppress printing a definition in the interface file -- b) when typechecking a pattern we can get from the -- Id back to the data con] + | ClassOpId Class -- An operation of a class + | PrimOpId PrimOp -- The Id for a primitive operator | FCallId ForeignCall -- The Id for a foreign call @@ -253,11 +250,12 @@ notGlobalId = NotGlobalId instance Outputable GlobalIdDetails where ppr NotGlobalId = ptext SLIT("[***NotGlobalId***]") ppr VanillaGlobal = ptext SLIT("[GlobalId]") - ppr (DataConId _) = ptext SLIT("[DataCon]") + 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 (RecordSelId _) = ptext SLIT("[RecSel]") + ppr (RecordSelId _ _) = ptext SLIT("[RecSel]") \end{code} @@ -292,7 +290,7 @@ data IdInfo #endif workerInfo :: WorkerInfo, -- Pointer to Worker Function unfoldingInfo :: Unfolding, -- Its unfolding - cgInfo :: CgInfo, -- Code generator info (arity, CAF info) + cafInfo :: CafInfo, -- CAF info lbvarInfo :: LBVarInfo, -- Info about a lambda-bound variable inlinePragInfo :: InlinePragInfo, -- Inline pragma occInfo :: OccInfo, -- How it occurs @@ -328,10 +326,8 @@ megaSeqIdInfo info seqCpr (cprInfo info) `seq` #endif --- CgInfo is involved in a loop, so we have to be careful not to seq it --- too early. --- seqCg (cgInfo info) `seq` - seqLBVar (lbvarInfo info) `seq` + seqCaf (cafInfo info) `seq` + seqLBVar (lbvarInfo info) `seq` seqOccInfo (occInfo info) \end{code} @@ -347,20 +343,11 @@ setStrictnessInfo info st = st `seq` info { strictnessInfo = st } #endif -- Try to avoid spack leaks by seq'ing -setUnfoldingInfo info uf - | isEvaldUnfolding uf - -- If the unfolding is a value, the demand info may - -- go pear-shaped, so we nuke it. Example: - -- let x = (a,b) in - -- case x of (p,q) -> h p q x - -- Here x is certainly demanded. But after we've nuked - -- the case, we'll get just - -- let x = (a,b) in h a b x - -- and now x is not demanded (I'm assuming h is lazy) - -- This really happens. The solution here is a bit ad hoc... - = info { unfoldingInfo = uf, newDemandInfo = Nothing } +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.) - | otherwise +setUnfoldingInfo info uf -- We do *not* seq on the unfolding info, For some reason, doing so -- actually increases residency significantly. = info { unfoldingInfo = uf } @@ -370,8 +357,8 @@ setDemandInfo info dd = info { demandInfo = dd } setCprInfo info cp = info { cprInfo = cp } #endif -setArityInfo info ar = info { arityInfo = ar } -setCgInfo info cg = info { cgInfo = cg } +setArityInfo info ar = info { arityInfo = ar } +setCafInfo info caf = info { cafInfo = caf } setLBVarInfo info lb = {-lb `seq`-} info { lbvarInfo = lb } @@ -384,7 +371,7 @@ setNewStrictnessInfo info dd = dd `seq` info { newStrictnessInfo = dd } vanillaIdInfo :: IdInfo vanillaIdInfo = IdInfo { - cgInfo = noCgInfo, + cafInfo = vanillaCafInfo, arityInfo = unknownArity, #ifdef OLD_STRICTNESS cprInfo = NoCPRInfo, @@ -401,11 +388,8 @@ vanillaIdInfo newStrictnessInfo = Nothing } -hasCafIdInfo = vanillaIdInfo `setCgInfo` CgInfo MayHaveCafRefs -noCafIdInfo = vanillaIdInfo `setCgInfo` CgInfo NoCafRefs +noCafIdInfo = vanillaIdInfo `setCafInfo` NoCafRefs -- Used for built-in type Ids in MkId. - -- These must have a valid CgInfo set, so you can't - -- use vanillaIdInfo! \end{code} @@ -489,14 +473,14 @@ this to". data WorkerInfo = NoWorker | HasWorker Id Arity -- The Arity is the arity of the *wrapper* at the moment of the - -- w/w split. See comments in MkIface.ifaceId, with the 'Worker' code. + -- w/w split. See notes above. seqWorker :: WorkerInfo -> () seqWorker (HasWorker id a) = id `seq` a `seq` () seqWorker NoWorker = () ppWorkerInfo NoWorker = empty -ppWorkerInfo (HasWorker wk_id _) = ptext SLIT("__P") <+> ppr wk_id +ppWorkerInfo (HasWorker wk_id _) = ptext SLIT("Worker") <+> ppr wk_id workerExists :: WorkerInfo -> Bool workerExists NoWorker = False @@ -516,31 +500,7 @@ wrapperArity (HasWorker _ a) = a %* * %************************************************************************ -CgInfo encapsulates calling-convention information produced by the code -generator. It is pasted into the IdInfo of each emitted Id by CoreTidy, -but only as a thunk --- the information is only actually produced further -downstream, by the code generator. - \begin{code} -#ifndef OLD_STRICTNESS -newtype CgInfo = CgInfo CafInfo -- We are back to only having CafRefs in CgInfo -noCgInfo = panic "NoCgInfo!" -#else -data CgInfo = CgInfo CafInfo - | NoCgInfo -- In debug mode we don't want a black hole here - -- See Id.idCgInfo - -- noCgInfo is used for local Ids, which shouldn't need any CgInfo -noCgInfo = NoCgInfo -#endif - -cgCafInfo (CgInfo caf_info) = caf_info - -setCafInfo info caf_info = info `setCgInfo` CgInfo caf_info - -seqCg c = c `seq` () -- fields are strict anyhow - -vanillaCgInfo = CgInfo MayHaveCafRefs -- Definitely safe - -- CafInfo is used to build Static Reference Tables (see simplStg/SRT.lhs). data CafInfo @@ -552,30 +512,17 @@ data CafInfo | NoCafRefs -- A function or static constructor -- that refers to no CAFs. +vanillaCafInfo = MayHaveCafRefs -- Definitely safe + mayHaveCafRefs MayHaveCafRefs = True mayHaveCafRefs _ = False seqCaf c = c `seq` () -pprCgInfo (CgInfo caf_info) = ppCafInfo caf_info - -ppArity 0 = empty -ppArity n = hsep [ptext SLIT("__A"), int n] - -ppCafInfo NoCafRefs = ptext SLIT("__C") +ppCafInfo NoCafRefs = ptext SLIT("NoCafRefs") ppCafInfo MayHaveCafRefs = empty \end{code} -\begin{code} -type CgInfoEnv = NameEnv CgInfo - -lookupCgInfo :: NameEnv CgInfo -> Name -> CgInfo -lookupCgInfo env n = case lookupNameEnv env n of - Just info -> info - Nothing -> pprTrace "Urk! Not in CgInfo env" (ppr n) vanillaCgInfo -\end{code} - - %************************************************************************ %* * \subsection[cpr-IdInfo]{Constructed Product Result info about an @Id@} @@ -638,42 +585,28 @@ instance Show CprInfo where %************************************************************************ If the @Id@ is a lambda-bound variable then it may have lambda-bound -var info. The usage analysis (UsageSP) detects whether the lambda -binding this var is a ``one-shot'' lambda; that is, whether it is -applied at most once. +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 - - | LBVarInfo Type -- The lambda that binds this Id has this usage - -- annotation (i.e., if ==usOnce, then the - -- lambda is applied at most once). - -- The annotation's kind must be `$' - -- HACK ALERT! placing this info here is a short-term hack, - -- but it minimises changes to the rest of the compiler. - -- Hack agreed by SLPJ/KSW 1999-04. +data LBVarInfo = NoLBVarInfo + | IsOneShotLambda -- The lambda is applied at most once). seqLBVar l = l `seq` () \end{code} \begin{code} -hasNoLBVarInfo NoLBVarInfo = True -hasNoLBVarInfo other = False +hasNoLBVarInfo NoLBVarInfo = True +hasNoLBVarInfo IsOneShotLambda = False noLBVarInfo = NoLBVarInfo --- not safe to print or parse LBVarInfo because it is not really a --- property of the definition, but a property of the context. pprLBVarInfo NoLBVarInfo = empty -pprLBVarInfo (LBVarInfo u) | u `eqUsage` usOnce - = ptext SLIT("OneShot") - | otherwise - = empty +pprLBVarInfo IsOneShotLambda = ptext SLIT("OneShot") instance Outputable LBVarInfo where ppr = pprLBVarInfo @@ -720,70 +653,3 @@ zapDemandInfo info@(IdInfo {newDemandInfo = dmd}) | otherwise = Nothing \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 (a) we must be careful about messing up rules - (b) we must ensure f's IdInfo ends up right - -(a) Messing up the rules -~~~~~~~~~~~~~~~~~~~~ -The example that went bad on me was this one: - - iterate :: (a -> a) -> a -> [a] - iterate = iterateList - - iterateFB c f x = x `c` iterateFB c f (f x) - iterateList f x = x : iterateList f (f x) - - {-# RULES - "iterate" forall f x. iterate f x = build (\c _n -> iterateFB c f x) - "iterateFB" iterateFB (:) = iterateList - #-} - -This got shorted out to: - - iterateList :: (a -> a) -> a -> [a] - iterateList = iterate - - iterateFB c f x = x `c` iterateFB c f (f x) - iterate f x = x : iterate f (f x) - - {-# RULES - "iterate" forall f x. iterate f x = build (\c _n -> iterateFB c f x) - "iterateFB" iterateFB (:) = iterate - #-} - -And now we get an infinite loop in the rule system - iterate f x -> build (\cn -> iterateFB c f x) - -> iterateFB (:) f x - -> iterate f x - -Tiresome solution: don't do shorting out if f has rewrite rules. -Hence shortableIdInfo. - -(b) Keeping the IdInfo right -~~~~~~~~~~~~~~~~~~~~~~~~ -We want to move strictness/worker info from f_local to f, but keep the rest. -Hence copyIdInfo. - -\begin{code} -shortableIdInfo :: IdInfo -> Bool -shortableIdInfo info = isEmptyCoreRules (specInfo info) - -copyIdInfo :: IdInfo -- f_local - -> IdInfo -- f (the exported one) - -> IdInfo -- New info for f -copyIdInfo f_local f = f { newStrictnessInfo = newStrictnessInfo f_local, -#ifdef OLD_STRICTNESS - strictnessInfo = strictnessInfo f_local, - cprInfo = cprInfo f_local, -#endif - workerInfo = workerInfo f_local - } -\end{code}