X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FsimplCore%2FSimplMonad.lhs;h=bc09e1128ce96c8dbc97fa159b21b3e52e003aa8;hb=9d7da331989abcd1844e9d03b8d1e4163796fa85;hp=c2771622e5a2c70149698e8d0ed0ca9375060756;hpb=f922d7032692a14890391d0720751c38ce0f7546;p=ghc-hetmet.git diff --git a/ghc/compiler/simplCore/SimplMonad.lhs b/ghc/compiler/simplCore/SimplMonad.lhs index c277162..bc09e11 100644 --- a/ghc/compiler/simplCore/SimplMonad.lhs +++ b/ghc/compiler/simplCore/SimplMonad.lhs @@ -5,26 +5,14 @@ \begin{code} module SimplMonad ( - InId, InBind, InExpr, InAlt, InArg, InType, InBinder, - OutId, OutBind, OutExpr, OutAlt, OutArg, OutType, OutBinder, - OutExprStuff, OutStuff, - - -- The continuation type - SimplCont(..), DupFlag(..), contIsDupable, contResultType, - contIsInteresting, pushArgs, discardCont, countValArgs, countArgs, - contIsInline, discardInlineCont, - -- The monad SimplM, initSmpl, returnSmpl, thenSmpl, thenSmpl_, mapSmpl, mapAndUnzipSmpl, mapAccumLSmpl, - - -- The inlining black-list - getBlackList, + getDOptsSmpl, -- Unique supply - getUniqueSmpl, getUniquesSmpl, - newId, newIds, + getUniqueSmpl, getUniquesSmpl, getUniqSupplySmpl, newId, -- Counting SimplCount, Tick(..), @@ -33,241 +21,39 @@ module SimplMonad ( plusSimplCount, isZeroSimplCount, -- Switch checker - SwitchChecker, getSwitchChecker, getSimplIntSwitch, - - -- Cost centres - getEnclosingCC, setEnclosingCC, - - -- Environments - getSubst, setSubst, - getSubstEnv, extendSubst, extendSubstList, - getInScope, setInScope, extendInScope, extendInScopes, modifyInScope, - setSubstEnv, zapSubstEnv, - getSimplBinderStuff, setSimplBinderStuff, - switchOffInlining + SwitchChecker, SwitchResult(..), getSimplIntSwitch, + isAmongSimpl, intSwitchSet, switchIsOn ) where #include "HsVersions.h" -import Const ( Con(DEFAULT) ) -import Id ( Id, mkSysLocal, idMustBeINLINEd ) -import IdInfo ( InlinePragInfo(..) ) -import Demand ( Demand ) -import CoreSyn -import PprCore () -- Instances -import Rules ( RuleBase ) -import CostCentre ( CostCentreStack, subsumedCCS ) -import Var ( TyVar ) -import VarEnv -import VarSet -import qualified Subst -import Subst ( Subst, emptySubst, mkSubst, - substTy, substEnv, - InScopeSet, substInScope, isInScope, lookupInScope - ) -import Type ( Type, TyVarSubst, applyTy ) +import Id ( Id, mkSysLocal ) +import Type ( Type ) import UniqSupply ( uniqsFromSupply, uniqFromSupply, splitUniqSupply, UniqSupply ) -import FiniteMap -import CmdLineOpts ( SimplifierSwitch(..), SwitchResult(..), - opt_PprStyle_Debug, opt_HistorySize, - intSwitchSet - ) +import DynFlags ( SimplifierSwitch(..), DynFlags, DynFlag(..), dopt ) +import StaticFlags ( opt_PprStyle_Debug, opt_HistorySize ) import Unique ( Unique ) import Maybes ( expectJust ) -import Util ( zipWithEqual ) +import FiniteMap ( FiniteMap, emptyFM, isEmptyFM, lookupFM, addToFM, plusFM_C, fmToList ) +import FastString ( FastString ) import Outputable +import FastTypes -infixr 9 `thenSmpl`, `thenSmpl_` -\end{code} - -%************************************************************************ -%* * -\subsection[Simplify-types]{Type declarations} -%* * -%************************************************************************ - -\begin{code} -type InBinder = CoreBndr -type InId = Id -- Not yet cloned -type InType = Type -- Ditto -type InBind = CoreBind -type InExpr = CoreExpr -type InAlt = CoreAlt -type InArg = CoreArg - -type OutBinder = CoreBndr -type OutId = Id -- Cloned -type OutType = Type -- Cloned -type OutBind = CoreBind -type OutExpr = CoreExpr -type OutAlt = CoreAlt -type OutArg = CoreArg - -type SwitchChecker = SimplifierSwitch -> SwitchResult -\end{code} - - -%************************************************************************ -%* * -\subsection{The continuation data type} -%* * -%************************************************************************ - -\begin{code} -type OutExprStuff = OutStuff (InScopeSet, OutExpr) -type OutStuff a = ([OutBind], a) - -- We return something equivalent to (let b in e), but - -- in pieces to avoid the quadratic blowup when floating - -- incrementally. Comments just before simplExprB in Simplify.lhs - -data SimplCont -- Strict contexts - = Stop OutType -- Type of the result - - | CoerceIt OutType -- The To-type, simplified - SimplCont - - | InlinePlease -- This continuation makes a function very - SimplCont -- keen to inline itelf - - | ApplyTo DupFlag - InExpr SubstEnv -- The argument, as yet unsimplified, - SimplCont -- and its subst-env - - | Select DupFlag - InId [InAlt] SubstEnv -- The case binder, alts, and subst-env - SimplCont - - | ArgOf DupFlag -- An arbitrary strict context: the argument - -- of a strict function, or a primitive-arg fn - -- or a PrimOp - OutType -- The type of the expression being sought by the context - -- f (error "foo") ==> coerce t (error "foo") - -- when f is strict - -- We need to know the type t, to which to coerce. - (OutExpr -> SimplM OutExprStuff) -- What to do with the result - -instance Outputable SimplCont where - ppr (Stop _) = ptext SLIT("Stop") - ppr (ApplyTo dup arg se cont) = (ptext SLIT("ApplyTo") <+> ppr dup <+> ppr arg) $$ ppr cont - ppr (ArgOf dup _ _) = ptext SLIT("ArgOf...") <+> ppr dup - ppr (Select dup bndr alts se cont) = (ptext SLIT("Select") <+> ppr dup <+> ppr bndr) $$ - (nest 4 (ppr alts)) $$ ppr cont - ppr (CoerceIt ty cont) = (ptext SLIT("CoerceIt") <+> ppr ty) $$ ppr cont - ppr (InlinePlease cont) = ptext SLIT("InlinePlease") $$ ppr cont - -data DupFlag = OkToDup | NoDup - -instance Outputable DupFlag where - ppr OkToDup = ptext SLIT("ok") - ppr NoDup = ptext SLIT("nodup") - -contIsDupable :: SimplCont -> Bool -contIsDupable (Stop _) = True -contIsDupable (ApplyTo OkToDup _ _ _) = True -contIsDupable (ArgOf OkToDup _ _) = True -contIsDupable (Select OkToDup _ _ _ _) = True -contIsDupable (CoerceIt _ cont) = contIsDupable cont -contIsDupable (InlinePlease cont) = contIsDupable cont -contIsDupable other = False - -contIsInline :: SimplCont -> Bool -contIsInline (InlinePlease cont) = True -contIsInline other = False - -discardInlineCont :: SimplCont -> SimplCont -discardInlineCont (InlinePlease cont) = cont -discardInlineCont cont = cont -\end{code} +import GLAEXTS ( indexArray# ) +#if __GLASGOW_HASKELL__ < 503 +import PrelArr ( Array(..) ) +#else +import GHC.Arr ( Array(..) ) +#endif -Comment about contIsInteresting -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -We want to avoid inlining an expression where there can't possibly be -any gain, such as in an argument position. Hence, if the continuation -is interesting (eg. a case scrutinee, application etc.) then we -inline, otherwise we don't. - -Previously some_benefit used to return True only if the variable was -applied to some value arguments. This didn't work: - - let x = _coerce_ (T Int) Int (I# 3) in - case _coerce_ Int (T Int) x of - I# y -> .... - -we want to inline x, but can't see that it's a constructor in a case -scrutinee position, and some_benefit is False. - -Another example: - -dMonadST = _/\_ t -> :Monad (g1 _@_ t, g2 _@_ t, g3 _@_ t) - -.... case dMonadST _@_ x0 of (a,b,c) -> .... - -we'd really like to inline dMonadST here, but we *don't* want to -inline if the case expression is just - - case x of y { DEFAULT -> ... } - -since we can just eliminate this case instead (x is in WHNF). Similar -applies when x is bound to a lambda expression. Hence -contIsInteresting looks for case expressions with just a single -default case. - -\begin{code} -contIsInteresting :: SimplCont -> Bool -contIsInteresting (Select _ _ alts _ _) = not (just_default alts) -contIsInteresting (CoerceIt _ cont) = contIsInteresting cont -contIsInteresting (ApplyTo _ (Type _) _ cont) = contIsInteresting cont -contIsInteresting (ApplyTo _ _ _ _) = True -contIsInteresting (ArgOf _ _ _) = True - -- If this call is the arg of a strict function, the context - -- is a bit interesting. If we inline here, we may get useful - -- evaluation information to avoid repeated evals: e.g. - -- x + (y * z) - -- Here the contIsInteresting makes the '*' keener to inline, - -- which in turn exposes a constructor which makes the '+' inline. - -- Assuming that +,* aren't small enough to inline regardless. -contIsInteresting (InlinePlease _) = True -contIsInteresting other = False - -just_default [(DEFAULT,_,_)] = True -- See notes below for why we look -just_default alts = False -- for this special case -\end{code} - +import Array ( array, (//) ) -\begin{code} -pushArgs :: SubstEnv -> [InExpr] -> SimplCont -> SimplCont -pushArgs se [] cont = cont -pushArgs se (arg:args) cont = ApplyTo NoDup arg se (pushArgs se args cont) - -discardCont :: SimplCont -- A continuation, expecting - -> SimplCont -- Replace the continuation with a suitable coerce -discardCont (Stop to_ty) = Stop to_ty -discardCont cont = CoerceIt to_ty (Stop to_ty) - where - to_ty = contResultType cont - -contResultType :: SimplCont -> OutType -contResultType (Stop to_ty) = to_ty -contResultType (ArgOf _ to_ty _) = to_ty -contResultType (ApplyTo _ _ _ cont) = contResultType cont -contResultType (CoerceIt _ cont) = contResultType cont -contResultType (InlinePlease cont) = contResultType cont -contResultType (Select _ _ _ _ cont) = contResultType cont - -countValArgs :: SimplCont -> Int -countValArgs (ApplyTo _ (Type ty) se cont) = countValArgs cont -countValArgs (ApplyTo _ val_arg se cont) = 1 + countValArgs cont -countValArgs other = 0 - -countArgs :: SimplCont -> Int -countArgs (ApplyTo _ arg se cont) = 1 + countArgs cont -countArgs other = 0 +infixr 0 `thenSmpl`, `thenSmpl_` \end{code} - %************************************************************************ %* * \subsection{Monad plumbing} @@ -278,47 +64,21 @@ For the simplifier monad, we want to {\em thread} a unique supply and a counter. (Command-line switches move around through the explicitly-passed SimplEnv.) \begin{code} -type SimplM result -- We thread the unique supply because - = SimplEnv -- constantly splitting it is rather expensive - -> UniqSupply - -> SimplCount - -> (result, UniqSupply, SimplCount) - -data SimplEnv - = SimplEnv { - seChkr :: SwitchChecker, - seCC :: CostCentreStack, -- The enclosing CCS (when profiling) - seBlackList :: Id -> Bool, -- True => don't inline this Id - seSubst :: Subst -- The current substitution - } - -- The range of the substitution is OutType and OutExpr resp - -- - -- The substitution is idempotent - -- It *must* be applied; things in its domain simply aren't - -- bound in the result. - -- - -- The substitution usually maps an Id to its clone, - -- but if the orig defn is a let-binding, and - -- the RHS of the let simplifies to an atom, - -- we just add the binding to the substitution and elide the let. - - -- The in-scope part of Subst includes *all* in-scope TyVars and Ids - -- The elements of the set may have better IdInfo than the - -- occurrences of in-scope Ids, and (more important) they will - -- have a correctly-substituted type. So we use a lookup in this - -- set to replace occurrences +newtype SimplM result + = SM { unSM :: DynFlags -- We thread the unique supply because + -> UniqSupply -- constantly splitting it is rather expensive + -> SimplCount + -> (result, UniqSupply, SimplCount)} \end{code} \begin{code} -initSmpl :: SwitchChecker +initSmpl :: DynFlags -> UniqSupply -- No init count; set to 0 - -> VarSet -- In scope (usually empty, but useful for nested calls) - -> (Id -> Bool) -- Black-list function -> SimplM a -> (a, SimplCount) -initSmpl chkr us in_scope black_list m - = case m (emptySimplEnv chkr in_scope black_list) us zeroSimplCount of +initSmpl dflags us m + = case unSM m dflags us (zeroSimplCount dflags) of (result, _, count) -> (result, count) @@ -326,19 +86,26 @@ initSmpl chkr us in_scope black_list m {-# INLINE thenSmpl_ #-} {-# INLINE returnSmpl #-} +instance Monad SimplM where + (>>) = thenSmpl_ + (>>=) = thenSmpl + return = returnSmpl + returnSmpl :: a -> SimplM a -returnSmpl e env us sc = (e, us, sc) +returnSmpl e = SM (\ dflags us sc -> (e, us, sc)) thenSmpl :: SimplM a -> (a -> SimplM b) -> SimplM b thenSmpl_ :: SimplM a -> SimplM b -> SimplM b -thenSmpl m k env us0 sc0 - = case (m env us0 sc0) of - (m_result, us1, sc1) -> k m_result env us1 sc1 +thenSmpl m k + = SM (\ dflags us0 sc0 -> + case (unSM m dflags us0 sc0) of + (m_result, us1, sc1) -> unSM (k m_result) dflags us1 sc1 ) -thenSmpl_ m k env us0 sc0 - = case (m env us0 sc0) of - (_, us1, sc1) -> k env us1 sc1 +thenSmpl_ m k + = SM (\dflags us0 sc0 -> + case (unSM m dflags us0 sc0) of + (_, us1, sc1) -> unSM k dflags us1 sc1) \end{code} @@ -358,6 +125,7 @@ mapAndUnzipSmpl f (x:xs) mapAndUnzipSmpl f xs `thenSmpl` \ (rs1, rs2) -> returnSmpl (r1:rs1, r2:rs2) +mapAccumLSmpl :: (acc -> b -> SimplM (acc,c)) -> acc -> [b] -> SimplM (acc, [c]) mapAccumLSmpl f acc [] = returnSmpl (acc, []) mapAccumLSmpl f acc (x:xs) = f acc x `thenSmpl` \ (acc', x') -> mapAccumLSmpl f acc' xs `thenSmpl` \ (acc'', xs') -> @@ -372,13 +140,28 @@ mapAccumLSmpl f acc (x:xs) = f acc x `thenSmpl` \ (acc', x') -> %************************************************************************ \begin{code} -getUniqueSmpl :: SimplM Unique -getUniqueSmpl env us sc = case splitUniqSupply us of - (us1, us2) -> (uniqFromSupply us1, us2, sc) +getUniqSupplySmpl :: SimplM UniqSupply +getUniqSupplySmpl + = SM (\dflags us sc -> case splitUniqSupply us of + (us1, us2) -> (us1, us2, sc)) -getUniquesSmpl :: Int -> SimplM [Unique] -getUniquesSmpl n env us sc = case splitUniqSupply us of - (us1, us2) -> (uniqsFromSupply n us1, us2, sc) +getUniqueSmpl :: SimplM Unique +getUniqueSmpl + = SM (\dflags us sc -> case splitUniqSupply us of + (us1, us2) -> (uniqFromSupply us1, us2, sc)) + +getUniquesSmpl :: SimplM [Unique] +getUniquesSmpl + = SM (\dflags us sc -> case splitUniqSupply us of + (us1, us2) -> (uniqsFromSupply us1, us2, sc)) + +getDOptsSmpl :: SimplM DynFlags +getDOptsSmpl + = SM (\dflags us sc -> (dflags, us, sc)) + +newId :: FastString -> Type -> SimplM Id +newId fs ty = getUniqueSmpl `thenSmpl` \ uniq -> + returnSmpl (mkSysLocal fs uniq ty) \end{code} @@ -390,26 +173,25 @@ getUniquesSmpl n env us sc = case splitUniqSupply us of \begin{code} getSimplCount :: SimplM SimplCount -getSimplCount env us sc = (sc, us, sc) +getSimplCount = SM (\dflags us sc -> (sc, us, sc)) tick :: Tick -> SimplM () -tick t env us sc = sc' `seq` ((), us, sc') - where - sc' = doTick t sc +tick t + = SM (\dflags us sc -> let sc' = doTick t sc + in sc' `seq` ((), us, sc')) freeTick :: Tick -> SimplM () -- Record a tick, but don't add to the total tick count, which is -- used to decide when nothing further has happened -freeTick t env us sc = sc' `seq` ((), us, sc') - where - sc' = doFreeTick t sc +freeTick t + = SM (\dflags us sc -> let sc' = doFreeTick t sc + in sc' `seq` ((), us, sc')) \end{code} \begin{code} verboseSimplStats = opt_PprStyle_Debug -- For now, anyway --- Defined both with and without debugging -zeroSimplCount :: SimplCount +zeroSimplCount :: DynFlags -> SimplCount isZeroSimplCount :: SimplCount -> Bool pprSimplCount :: SimplCount -> SDoc doTick, doFreeTick :: Tick -> SimplCount -> SimplCount @@ -417,29 +199,11 @@ plusSimplCount :: SimplCount -> SimplCount -> SimplCount \end{code} \begin{code} -#ifndef DEBUG ----------------------------------------------------------- --- Debugging OFF ----------------------------------------------------------- -type SimplCount = Int - -zeroSimplCount = 0 - -isZeroSimplCount n = n==0 - -doTick t n = n+1 -- Very basic when not debugging -doFreeTick t n = n -- Don't count leaf visits +data SimplCount = VerySimplZero -- These two are used when + | VerySimplNonZero -- we are only interested in + -- termination info -pprSimplCount n = ptext SLIT("Total ticks:") <+> int n - -plusSimplCount n m = n+m - -#else ----------------------------------------------------------- --- Debugging ON ----------------------------------------------------------- - -data SimplCount = SimplCount { + | SimplCount { ticks :: !Int, -- Total ticks details :: !TickCounts, -- How many of each type n_log :: !Int, -- N @@ -449,15 +213,24 @@ data SimplCount = SimplCount { type TickCounts = FiniteMap Tick Int -zeroSimplCount = SimplCount {ticks = 0, details = emptyFM, - n_log = 0, log1 = [], log2 = []} +zeroSimplCount dflags + -- This is where we decide whether to do + -- the VerySimpl version or the full-stats version + | dopt Opt_D_dump_simpl_stats dflags + = SimplCount {ticks = 0, details = emptyFM, + n_log = 0, log1 = [], log2 = []} + | otherwise + = VerySimplZero -isZeroSimplCount sc = ticks sc == 0 +isZeroSimplCount VerySimplZero = True +isZeroSimplCount (SimplCount { ticks = 0 }) = True +isZeroSimplCount other = False doFreeTick tick sc@SimplCount { details = dts } = dts' `seqFM` sc { details = dts' } where dts' = dts `addTick` tick +doFreeTick tick sc = sc -- Gross hack to persuade GHC 3.03 to do this important seq seqFM fm x | isEmptyFM fm = x @@ -469,6 +242,9 @@ doTick tick sc@SimplCount { ticks = tks, details = dts, n_log = nl, log1 = l1, l where sc1 = sc { ticks = tks+1, details = dts `addTick` tick } +doTick tick sc = VerySimplNonZero -- The very simple case + + -- Don't use plusFM_C because that's lazy, and we want to -- be pretty strict here! addTick :: TickCounts -> Tick -> TickCounts @@ -478,6 +254,7 @@ addTick fm tick = case lookupFM fm tick of where n1 = n+1 + plusSimplCount sc1@(SimplCount { ticks = tks1, details = dts1 }) sc2@(SimplCount { ticks = tks2, details = dts2 }) = log_base { ticks = tks1 + tks2, details = plusFM_C (+) dts1 dts2 } @@ -487,7 +264,11 @@ plusSimplCount sc1@(SimplCount { ticks = tks1, details = dts1 }) | null (log2 sc2) = sc2 { log2 = log1 sc1 } | otherwise = sc2 +plusSimplCount VerySimplZero VerySimplZero = VerySimplZero +plusSimplCount sc1 sc2 = VerySimplNonZero +pprSimplCount VerySimplZero = ptext SLIT("Total ticks: ZERO!") +pprSimplCount VerySimplNonZero = ptext SLIT("Total ticks: NON-ZERO!") pprSimplCount (SimplCount { ticks = tks, details = dts, log1 = l1, log2 = l2 }) = vcat [ptext SLIT("Total ticks: ") <+> int tks, text "", @@ -518,7 +299,6 @@ pprTCDetails ticks@((tick,_):_) = nest 4 (vcat [int n <+> pprTickCts tick | (tick,n) <- ticks]) | otherwise = empty -#endif \end{code} %************************************************************************ @@ -533,9 +313,9 @@ data Tick | PostInlineUnconditionally Id | UnfoldingDone Id - | RuleFired FAST_STRING -- Rule name + | RuleFired FastString -- Rule name - | LetFloatFromLet Id -- Thing floated out + | LetFloatFromLet | EtaExpansion Id -- LHS binder | EtaReduction Id -- Binder on outer lambda | BetaReduction Id -- Lambda binder @@ -544,12 +324,12 @@ data Tick | CaseOfCase Id -- Bndr on *inner* case | KnownBranch Id -- Case binder | CaseMerge Id -- Binder on outer case + | AltMerge Id -- Case binder | CaseElim Id -- Case binder | CaseIdentity Id -- Case binder | FillInCaseDefault Id -- Case binder | BottomFound - | LeafVisit | SimplifierDone -- Ticked at each iteration of the simplifier isRuleFired (RuleFired _) = True @@ -569,7 +349,7 @@ tickToTag (PreInlineUnconditionally _) = 0 tickToTag (PostInlineUnconditionally _) = 1 tickToTag (UnfoldingDone _) = 2 tickToTag (RuleFired _) = 3 -tickToTag (LetFloatFromLet _) = 4 +tickToTag LetFloatFromLet = 4 tickToTag (EtaExpansion _) = 5 tickToTag (EtaReduction _) = 6 tickToTag (BetaReduction _) = 7 @@ -580,40 +360,41 @@ tickToTag (CaseElim _) = 11 tickToTag (CaseIdentity _) = 12 tickToTag (FillInCaseDefault _) = 13 tickToTag BottomFound = 14 -tickToTag LeafVisit = 15 tickToTag SimplifierDone = 16 +tickToTag (AltMerge _) = 17 tickString :: Tick -> String tickString (PreInlineUnconditionally _) = "PreInlineUnconditionally" tickString (PostInlineUnconditionally _)= "PostInlineUnconditionally" tickString (UnfoldingDone _) = "UnfoldingDone" tickString (RuleFired _) = "RuleFired" -tickString (LetFloatFromLet _) = "LetFloatFromLet" +tickString LetFloatFromLet = "LetFloatFromLet" tickString (EtaExpansion _) = "EtaExpansion" tickString (EtaReduction _) = "EtaReduction" tickString (BetaReduction _) = "BetaReduction" tickString (CaseOfCase _) = "CaseOfCase" tickString (KnownBranch _) = "KnownBranch" tickString (CaseMerge _) = "CaseMerge" +tickString (AltMerge _) = "AltMerge" tickString (CaseElim _) = "CaseElim" tickString (CaseIdentity _) = "CaseIdentity" tickString (FillInCaseDefault _) = "FillInCaseDefault" tickString BottomFound = "BottomFound" tickString SimplifierDone = "SimplifierDone" -tickString LeafVisit = "LeafVisit" pprTickCts :: Tick -> SDoc pprTickCts (PreInlineUnconditionally v) = ppr v pprTickCts (PostInlineUnconditionally v)= ppr v pprTickCts (UnfoldingDone v) = ppr v pprTickCts (RuleFired v) = ppr v -pprTickCts (LetFloatFromLet v) = ppr v +pprTickCts LetFloatFromLet = empty pprTickCts (EtaExpansion v) = ppr v pprTickCts (EtaReduction v) = ppr v pprTickCts (BetaReduction v) = ppr v pprTickCts (CaseOfCase v) = ppr v pprTickCts (KnownBranch v) = ppr v pprTickCts (CaseMerge v) = ppr v +pprTickCts (AltMerge v) = ppr v pprTickCts (CaseElim v) = ppr v pprTickCts (CaseIdentity v) = ppr v pprTickCts (FillInCaseDefault v) = ppr v @@ -633,13 +414,13 @@ cmpEqTick (PreInlineUnconditionally a) (PreInlineUnconditionally b) = a `compare cmpEqTick (PostInlineUnconditionally a) (PostInlineUnconditionally b) = a `compare` b cmpEqTick (UnfoldingDone a) (UnfoldingDone b) = a `compare` b cmpEqTick (RuleFired a) (RuleFired b) = a `compare` b -cmpEqTick (LetFloatFromLet a) (LetFloatFromLet b) = a `compare` b cmpEqTick (EtaExpansion a) (EtaExpansion b) = a `compare` b cmpEqTick (EtaReduction a) (EtaReduction b) = a `compare` b cmpEqTick (BetaReduction a) (BetaReduction b) = a `compare` b cmpEqTick (CaseOfCase a) (CaseOfCase b) = a `compare` b cmpEqTick (KnownBranch a) (KnownBranch b) = a `compare` b cmpEqTick (CaseMerge a) (CaseMerge b) = a `compare` b +cmpEqTick (AltMerge a) (AltMerge b) = a `compare` b cmpEqTick (CaseElim a) (CaseElim b) = a `compare` b cmpEqTick (CaseIdentity a) (CaseIdentity b) = a `compare` b cmpEqTick (FillInCaseDefault a) (FillInCaseDefault b) = a `compare` b @@ -654,191 +435,92 @@ cmpEqTick other1 other2 = EQ %************************************************************************ \begin{code} -getSwitchChecker :: SimplM SwitchChecker -getSwitchChecker env us sc = (seChkr env, us, sc) +type SwitchChecker = SimplifierSwitch -> SwitchResult -getSimplIntSwitch :: SwitchChecker -> (Int-> SimplifierSwitch) -> Int -getSimplIntSwitch chkr switch - = expectJust "getSimplIntSwitch" (intSwitchSet chkr switch) +data SwitchResult + = SwBool Bool -- on/off + | SwString FastString -- nothing or a String + | SwInt Int -- nothing or an Int + +isAmongSimpl :: [SimplifierSwitch] -> SimplifierSwitch -> SwitchResult +isAmongSimpl on_switches -- Switches mentioned later occur *earlier* + -- in the list; defaults right at the end. + = let + tidied_on_switches = foldl rm_dups [] on_switches + -- The fold*l* ensures that we keep the latest switches; + -- ie the ones that occur earliest in the list. + + sw_tbl :: Array Int SwitchResult + sw_tbl = (array (0, lAST_SIMPL_SWITCH_TAG) -- bounds... + all_undefined) + // defined_elems + + all_undefined = [ (i, SwBool False) | i <- [0 .. lAST_SIMPL_SWITCH_TAG ] ] + + defined_elems = map mk_assoc_elem tidied_on_switches + in + -- (avoid some unboxing, bounds checking, and other horrible things:) + case sw_tbl of { Array _ _ stuff -> + \ switch -> + case (indexArray# stuff (tagOf_SimplSwitch switch)) of + (# v #) -> v + } + where + mk_assoc_elem k@(MaxSimplifierIterations lvl) + = (iBox (tagOf_SimplSwitch k), SwInt lvl) + mk_assoc_elem k + = (iBox (tagOf_SimplSwitch k), SwBool True) -- I'm here, Mom! + + -- cannot have duplicates if we are going to use the array thing + rm_dups switches_so_far switch + = if switch `is_elem` switches_so_far + then switches_so_far + else switch : switches_so_far + where + sw `is_elem` [] = False + sw `is_elem` (s:ss) = (tagOf_SimplSwitch sw) ==# (tagOf_SimplSwitch s) + || sw `is_elem` ss \end{code} - -@switchOffInlining@ is used to prepare the environment for simplifying -the RHS of an Id that's marked with an INLINE pragma. It is going to -be inlined wherever they are used, and then all the inlining will take -effect. Meanwhile, there isn't much point in doing anything to the -as-yet-un-INLINEd rhs. Furthremore, it's very important to switch off -inlining! because - (a) not doing so will inline a worker straight back into its wrapper! - -and (b) Consider the following example - let f = \pq -> BIG - in - let g = \y -> f y y - {-# INLINE g #-} - in ...g...g...g...g...g... - - Now, if that's the ONLY occurrence of f, it will be inlined inside g, - and thence copied multiple times when g is inlined. - - Andy disagrees! Example: - all xs = foldr (&&) True xs - any p = all . map p {-# INLINE any #-} - - Problem: any won't get deforested, and so if it's exported and - the importer doesn't use the inlining, (eg passes it as an arg) - then we won't get deforestation at all. - We havn't solved this problem yet! - -We prepare the envt by simply modifying the in_scope_env, which has all the -unfolding info. At one point we did it by modifying the chkr so that -it said "EssentialUnfoldingsOnly", but that prevented legitmate, and -important, simplifications happening in the body of the RHS. - -6/98 update: - -We *don't* prevent inlining from happening for identifiers -that are marked as IMustBeINLINEd. An example of where -doing this is crucial is: - - class Bar a => Foo a where - ...g.... - {-# INLINE f #-} - f :: Foo a => a -> b - f x = ....Foo_sc1... - -If `f' needs to peer inside Foo's superclass, Bar, it refers -to the appropriate super class selector, which is marked as -must-inlineable. We don't generate any code for a superclass -selector, so failing to inline it in the RHS of `f' will -leave a reference to a non-existent id, with bad consequences. - -ALSO NOTE that we do all this by modifing the inline-pragma, -not by zapping the unfolding. The latter may still be useful for -knowing when something is evaluated. - -June 98 update: I've gone back to dealing with this by adding -the EssentialUnfoldingsOnly switch. That doesn't stop essential -unfoldings, nor inlineUnconditionally stuff; and the thing's going -to be inlined at every call site anyway. Running over the whole -environment seems like wild overkill. - \begin{code} -switchOffInlining :: SimplM a -> SimplM a -switchOffInlining m env us sc - = m (env { seBlackList = \v -> True }) us sc -\end{code} +getSimplIntSwitch :: SwitchChecker -> (Int-> SimplifierSwitch) -> Int +getSimplIntSwitch chkr switch + = expectJust "getSimplIntSwitch" (intSwitchSet chkr switch) +switchIsOn :: (switch -> SwitchResult) -> switch -> Bool -%************************************************************************ -%* * -\subsubsection{The ``enclosing cost-centre''} -%* * -%************************************************************************ +switchIsOn lookup_fn switch + = case (lookup_fn switch) of + SwBool False -> False + _ -> True -\begin{code} -getEnclosingCC :: SimplM CostCentreStack -getEnclosingCC env us sc = (seCC env, us, sc) +intSwitchSet :: (switch -> SwitchResult) + -> (Int -> switch) + -> Maybe Int -setEnclosingCC :: CostCentreStack -> SimplM a -> SimplM a -setEnclosingCC cc m env us sc = m (env { seCC = cc }) us sc +intSwitchSet lookup_fn switch + = case (lookup_fn (switch (panic "intSwitchSet"))) of + SwInt int -> Just int + _ -> Nothing \end{code} -%************************************************************************ -%* * -\subsubsection{The @SimplEnv@ type} -%* * -%************************************************************************ - +These things behave just like enumeration types. \begin{code} -emptySimplEnv :: SwitchChecker -> InScopeSet -> (Id -> Bool) -> SimplEnv - -emptySimplEnv sw_chkr in_scope black_list - = SimplEnv { seChkr = sw_chkr, seCC = subsumedCCS, - seBlackList = black_list, - seSubst = mkSubst in_scope emptySubstEnv } - -- The top level "enclosing CC" is "SUBSUMED". - -getSubst :: SimplM Subst -getSubst env us sc = (seSubst env, us, sc) - -getBlackList :: SimplM (Id -> Bool) -getBlackList env us sc = (seBlackList env, us, sc) - -setSubst :: Subst -> SimplM a -> SimplM a -setSubst subst m env us sc = m (env {seSubst = subst}) us sc - -getSubstEnv :: SimplM SubstEnv -getSubstEnv env us sc = (substEnv (seSubst env), us, sc) +instance Eq SimplifierSwitch where + a == b = tagOf_SimplSwitch a ==# tagOf_SimplSwitch b -extendInScope :: CoreBndr -> SimplM a -> SimplM a -extendInScope v m env@(SimplEnv {seSubst = subst}) us sc - = m (env {seSubst = Subst.extendInScope subst v}) us sc +instance Ord SimplifierSwitch where + a < b = tagOf_SimplSwitch a <# tagOf_SimplSwitch b + a <= b = tagOf_SimplSwitch a <=# tagOf_SimplSwitch b -extendInScopes :: [CoreBndr] -> SimplM a -> SimplM a -extendInScopes vs m env@(SimplEnv {seSubst = subst}) us sc - = m (env {seSubst = Subst.extendInScopes subst vs}) us sc -getInScope :: SimplM InScopeSet -getInScope env us sc = (substInScope (seSubst env), us, sc) +tagOf_SimplSwitch (MaxSimplifierIterations _) = _ILIT(1) +tagOf_SimplSwitch NoCaseOfCase = _ILIT(2) -setInScope :: InScopeSet -> SimplM a -> SimplM a -setInScope in_scope m env@(SimplEnv {seSubst = subst}) us sc - = m (env {seSubst = Subst.setInScope subst in_scope}) us sc +-- If you add anything here, be sure to change lAST_SIMPL_SWITCH_TAG, too! -modifyInScope :: CoreBndr -> SimplM a -> SimplM a -modifyInScope v m env us sc -#ifdef DEBUG - | not (v `isInScope` seSubst env) - = pprTrace "modifyInScope: not in scope:" (ppr v) - m env us sc -#endif - | otherwise - = extendInScope v m env us sc - -extendSubst :: CoreBndr -> SubstResult -> SimplM a -> SimplM a -extendSubst var res m env@(SimplEnv {seSubst = subst}) us sc - = m (env { seSubst = Subst.extendSubst subst var res }) us sc - -extendSubstList :: [CoreBndr] -> [SubstResult] -> SimplM a -> SimplM a -extendSubstList vars ress m env@(SimplEnv {seSubst = subst}) us sc - = m (env { seSubst = Subst.extendSubstList subst vars ress }) us sc - -setSubstEnv :: SubstEnv -> SimplM a -> SimplM a -setSubstEnv senv m env@(SimplEnv {seSubst = subst}) us sc - = m (env {seSubst = Subst.setSubstEnv subst senv}) us sc - -zapSubstEnv :: SimplM a -> SimplM a -zapSubstEnv m env@(SimplEnv {seSubst = subst}) us sc - = m (env {seSubst = Subst.zapSubstEnv subst}) us sc - -getSimplBinderStuff :: SimplM (Subst, UniqSupply) -getSimplBinderStuff (SimplEnv {seSubst = subst}) us sc - = ((subst, us), us, sc) - -setSimplBinderStuff :: (Subst, UniqSupply) -> SimplM a -> SimplM a -setSimplBinderStuff (subst, us) m env _ sc - = m (env {seSubst = subst}) us sc +lAST_SIMPL_SWITCH_TAG = 2 \end{code} - -\begin{code} -newId :: Type -> (Id -> SimplM a) -> SimplM a - -- Extends the in-scope-env too -newId ty m env@(SimplEnv {seSubst = subst}) us sc - = case splitUniqSupply us of - (us1, us2) -> m v (env {seSubst = Subst.extendInScope subst v}) us2 sc - where - v = mkSysLocal SLIT("s") (uniqFromSupply us1) ty - -newIds :: [Type] -> ([Id] -> SimplM a) -> SimplM a -newIds tys m env@(SimplEnv {seSubst = subst}) us sc - = case splitUniqSupply us of - (us1, us2) -> m vs (env {seSubst = Subst.extendInScopes subst vs}) us2 sc - where - vs = zipWithEqual "newIds" (mkSysLocal SLIT("s")) - (uniqsFromSupply (length tys) us1) tys - -\end{code}