X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FsimplCore%2FSimplCore.lhs;h=ff7749e7057607f6a06b6c7e24b7b26477edf7e4;hb=940841711bb0c30326a5173d8107c2792919641c;hp=970838f3c2572c8413e821f25d26ab2f0da3030b;hpb=1fa4a56319ce1b5827d2101cc9fa256196517a4f;p=ghc-hetmet.git diff --git a/ghc/compiler/simplCore/SimplCore.lhs b/ghc/compiler/simplCore/SimplCore.lhs index 970838f..ff7749e 100644 --- a/ghc/compiler/simplCore/SimplCore.lhs +++ b/ghc/compiler/simplCore/SimplCore.lhs @@ -25,15 +25,15 @@ import Rules ( RuleBase, ProtoCoreRule(..), pprProtoCoreRule, prepareRuleBase, import CoreUnfold import PprCore ( pprCoreBindings ) import OccurAnal ( occurAnalyseBinds ) -import CoreUtils ( exprIsTrivial, coreExprType ) +import CoreUtils ( exprIsTrivial, etaReduceExpr ) import Simplify ( simplTopBinds, simplExpr ) -import SimplUtils ( etaCoreExpr, findDefault, simplBinders ) +import SimplUtils ( findDefault, simplBinders ) import SimplMonad -import Const ( Con(..), Literal(..), literalType, mkMachInt ) +import Literal ( Literal(..), literalType, mkMachInt ) import ErrUtils ( dumpIfSet ) import FloatIn ( floatInwards ) import FloatOut ( floatOutwards ) -import Id ( Id, mkSysLocal, mkVanillaId, isBottomingId, +import Id ( Id, mkSysLocal, mkVanillaId, isBottomingId, isDataConWrapId, idType, setIdType, idName, idInfo, setIdNoDiscard ) import VarEnv @@ -43,9 +43,8 @@ import Name ( mkLocalName, tidyOccName, tidyTopName, NamedThing(..), OccName ) import TyCon ( TyCon, isDataTyCon ) -import PrimOp ( PrimOp(..) ) -import PrelInfo ( unpackCStringId, unpackCString2Id, addr2IntegerId ) -import Type ( Type, splitAlgTyConApp_maybe, +import PrelRules ( builtinRules ) +import Type ( Type, isUnLiftedType, tidyType, tidyTypes, tidyTopType, tidyTyVar, tidyTyVars, Type @@ -59,11 +58,8 @@ import StrictAnal ( saBinds ) import WorkWrap ( wwTopBinds ) import CprAnalyse ( cprAnalyse ) -import Unique ( Unique, Uniquable(..), - ratioTyConKey - ) +import Unique ( Unique, Uniquable(..) ) import UniqSupply ( UniqSupply, mkSplitUniqSupply, splitUniqSupply, uniqFromSupply ) -import Constants ( tARGET_MIN_INT, tARGET_MAX_INT ) import Util ( mapAccumL ) import SrcLoc ( noSrcLoc ) import Bag @@ -94,7 +90,10 @@ core2core core_todos binds rules better_rules <- simplRules ru_us rules binds - let (binds1, rule_base) = prepareRuleBase binds better_rules + let all_rules = builtinRules ++ better_rules + -- Here is where we add in the built-in rules + + let (binds1, rule_base) = prepareRuleBase binds all_rules -- Do the main business (stats, processed_binds) <- doCorePasses zeroSimplCount cp_us binds1 @@ -104,11 +103,8 @@ core2core core_todos binds rules "Grand total simplifier statistics" (pprSimplCount stats) - -- Do the post-simplification business - post_simpl_binds <- doPostSimplification ps_us processed_binds - -- Return results - return (post_simpl_binds, filter orphanRule better_rules) + return (processed_binds, filter orphanRule better_rules) doCorePasses stats us binds irs [] @@ -124,7 +120,7 @@ doCorePass us binds rb (CoreDoSimplify sw_chkr) = _scc_ "Simplify" simplify doCorePass us binds rb CoreCSE = _scc_ "CommonSubExpr" noStats (cseProgram binds) doCorePass us binds rb CoreLiberateCase = _scc_ "LiberateCase" noStats (liberateCase binds) doCorePass us binds rb CoreDoFloatInwards = _scc_ "FloatInwards" noStats (floatInwards binds) -doCorePass us binds rb CoreDoFullLaziness = _scc_ "FloatOutwards" noStats (floatOutwards us binds) +doCorePass us binds rb (CoreDoFloatOutwards f) = _scc_ "FloatOutwards" noStats (floatOutwards f us binds) doCorePass us binds rb CoreDoStaticArgs = _scc_ "StaticArgs" noStats (doStaticArgs us binds) doCorePass us binds rb CoreDoStrictness = _scc_ "Stranal" noStats (saBinds binds) doCorePass us binds rb CoreDoWorkerWrapper = _scc_ "WorkWrap" noStats (wwTopBinds us binds) @@ -170,8 +166,11 @@ simplRules us rules binds return better_rules where - black_list_all v = True -- This stops all inlining - sw_chkr any = SwBool False -- A bit bogus + black_list_all v = not (isDataConWrapId v) + -- This stops all inlining except the + -- wrappers for data constructors + + sw_chkr any = SwBool False -- A bit bogus -- Boringly, we need to gather the in-scope set. -- Typically this thunk won't even be force, but the test in @@ -184,9 +183,20 @@ simplRule rule@(ProtoCoreRule is_local id (Rule name bndrs args rhs)) = returnSmpl rule -- No need to fiddle with imported rules | otherwise = simplBinders bndrs $ \ bndrs' -> - mapSmpl simplExpr args `thenSmpl` \ args' -> + mapSmpl simpl_arg args `thenSmpl` \ args' -> simplExpr rhs `thenSmpl` \ rhs' -> returnSmpl (ProtoCoreRule is_local id (Rule name bndrs' args' rhs')) + +simpl_arg e +-- I've seen rules in which a LHS like +-- augment g (build h) +-- turns into +-- augment (\a. g a) (build h) +-- So it's a help to eta-reduce the args as we simplify them. +-- Otherwise we don't match when given an argument like +-- (\a. h a a) + = simplExpr e `thenSmpl` \ e' -> + returnSmpl (etaReduceExpr e') \end{code} %************************************************************************ @@ -306,287 +316,3 @@ simplifyPgm (imported_rule_ids, rule_lhs_fvs) where (us1, us2) = splitUniqSupply us \end{code} - - -%************************************************************************ -%* * -\subsection{PostSimplification} -%* * -%************************************************************************ - -Several tasks are performed by the post-simplification pass - -1. Make the representation of NoRep literals explicit, and - float their bindings to the top level. We only do the floating - part for NoRep lits inside a lambda (else no gain). We need to - take care with let x = "foo" in e - that we don't end up with a silly binding - let x = y in e - with a floated "foo". What a bore. - -4. Do eta reduction for lambda abstractions appearing in: - - the RHS of case alternatives - - the body of a let - - These will otherwise turn into local bindings during Core->STG; - better to nuke them if possible. (In general the simplifier does - eta expansion not eta reduction, up to this point. It does eta - on the RHSs of bindings but not the RHSs of case alternatives and - let bodies) - - -------------------- NOT DONE ANY MORE ------------------------ -[March 98] Indirections are now elimianted by the occurrence analyser -1. Eliminate indirections. The point here is to transform - x_local = E - x_exported = x_local - ==> - x_exported = E - -[Dec 98] [Not now done because there is no penalty in the code - generator for using the former form] -2. Convert - case x of {...; x' -> ...x'...} - ==> - case x of {...; _ -> ...x... } - See notes in SimplCase.lhs, near simplDefault for the reasoning here. --------------------------------------------------------------- - -Special case -~~~~~~~~~~~~ - -NOT ENABLED AT THE MOMENT (because the floated Ids are global-ish -things, and we need local Ids for non-floated stuff): - - Don't float stuff out of a binder that's marked as a bottoming Id. - Reason: it doesn't do any good, and creates more CAFs that increase - the size of SRTs. - -eg. - - f = error "string" - -is translated to - - f' = unpackCString# "string" - f = error f' - -hence f' and f become CAFs. Instead, the special case for -tidyTopBinding below makes sure this comes out as - - f = let f' = unpackCString# "string" in error f' - -and we can safely ignore f as a CAF, since it can only ever be entered once. - - - -\begin{code} -doPostSimplification :: UniqSupply -> [CoreBind] -> IO [CoreBind] -doPostSimplification us binds_in - = do - beginPass "Post-simplification pass" - let binds_out = initPM us (postSimplTopBinds binds_in) - endPass "Post-simplification pass" opt_D_verbose_core2core binds_out - -postSimplTopBinds :: [CoreBind] -> PostM [CoreBind] -postSimplTopBinds binds - = mapPM postSimplTopBind binds `thenPM` \ binds' -> - returnPM (bagToList (unionManyBags binds')) - -postSimplTopBind :: CoreBind -> PostM (Bag CoreBind) -postSimplTopBind (NonRec bndr rhs) - | isBottomingId bndr -- Don't lift out floats for bottoming Ids - -- See notes above - = getFloatsPM (postSimplExpr rhs) `thenPM` \ (rhs', floats) -> - returnPM (unitBag (NonRec bndr (foldrBag Let rhs' floats))) - -postSimplTopBind bind - = getFloatsPM (postSimplBind bind) `thenPM` \ (bind', floats) -> - returnPM (floats `snocBag` bind') - -postSimplBind (NonRec bndr rhs) - = postSimplExpr rhs `thenPM` \ rhs' -> - returnPM (NonRec bndr rhs') - -postSimplBind (Rec pairs) - = mapPM postSimplExpr rhss `thenPM` \ rhss' -> - returnPM (Rec (bndrs `zip` rhss')) - where - (bndrs, rhss) = unzip pairs -\end{code} - - -Expressions -~~~~~~~~~~~ -\begin{code} -postSimplExpr (Var v) = returnPM (Var v) -postSimplExpr (Type ty) = returnPM (Type ty) - -postSimplExpr (App fun arg) - = postSimplExpr fun `thenPM` \ fun' -> - postSimplExpr arg `thenPM` \ arg' -> - returnPM (App fun' arg') - -postSimplExpr (Con (Literal lit) args) - = ASSERT( null args ) - litToRep lit `thenPM` \ (lit_ty, lit_expr) -> - getInsideLambda `thenPM` \ in_lam -> - if in_lam && not (exprIsTrivial lit_expr) then - -- It must have been a no-rep literal with a - -- non-trivial representation; and we're inside a lambda; - -- so float it to the top - addTopFloat lit_ty lit_expr `thenPM` \ v -> - returnPM (Var v) - else - returnPM lit_expr - -postSimplExpr (Con con args) - = mapPM postSimplExpr args `thenPM` \ args' -> - returnPM (Con con args') - -postSimplExpr (Lam bndr body) - = insideLambda bndr $ - postSimplExpr body `thenPM` \ body' -> - returnPM (Lam bndr body') - -postSimplExpr (Let bind body) - = postSimplBind bind `thenPM` \ bind' -> - postSimplExprEta body `thenPM` \ body' -> - returnPM (Let bind' body') - -postSimplExpr (Note note body) - = postSimplExpr body `thenPM` \ body' -> - -- Do *not* call postSimplExprEta here - -- We don't want to turn f = \x -> coerce t (\y -> f x y) - -- into f = \x -> coerce t (f x) - -- because then f has a lower arity. - -- This is not only bad in general, it causes the arity to - -- not match the [Demand] on an Id, - -- which confuses the importer of this module. - returnPM (Note note body') - -postSimplExpr (Case scrut case_bndr alts) - = postSimplExpr scrut `thenPM` \ scrut' -> - mapPM ps_alt alts `thenPM` \ alts' -> - returnPM (Case scrut' case_bndr alts') - where - ps_alt (con,bndrs,rhs) = postSimplExprEta rhs `thenPM` \ rhs' -> - returnPM (con, bndrs, rhs') - -postSimplExprEta e = postSimplExpr e `thenPM` \ e' -> - returnPM (etaCoreExpr e') -\end{code} - - -%************************************************************************ -%* * -\subsection[coreToStg-lits]{Converting literals} -%* * -%************************************************************************ - -Literals: the NoRep kind need to be de-no-rep'd. -We always replace them with a simple variable, and float a suitable -binding out to the top level. - -\begin{code} -litToRep :: Literal -> PostM (Type, CoreExpr) - -litToRep (NoRepStr s ty) - = returnPM (ty, rhs) - where - rhs = if (any is_NUL (_UNPK_ s)) - - then -- Must cater for NULs in literal string - mkApps (Var unpackCString2Id) - [mkLit (MachStr s), - mkLit (mkMachInt (toInteger (_LENGTH_ s)))] - - else -- No NULs in the string - App (Var unpackCStringId) (mkLit (MachStr s)) - - is_NUL c = c == '\0' -\end{code} - -If an Integer is small enough (Haskell implementations must support -Ints in the range $[-2^29+1, 2^29-1]$), wrap it up in @int2Integer@; -otherwise, wrap with @addr2Integer@. - -\begin{code} -litToRep (NoRepInteger i integer_ty) - = returnPM (integer_ty, rhs) - where - rhs | i >= tARGET_MIN_INT && -- Small enough, so start from an Int - i <= tARGET_MAX_INT - = Con (DataCon smallIntegerDataCon) [Con (Literal (mkMachInt i)) []] - - | otherwise -- Big, so start from a string - = App (Var addr2IntegerId) (Con (Literal (MachStr (_PK_ (show i)))) []) - - -litToRep (NoRepRational r rational_ty) - = postSimplExpr (mkLit (NoRepInteger (numerator r) integer_ty)) `thenPM` \ num_arg -> - postSimplExpr (mkLit (NoRepInteger (denominator r) integer_ty)) `thenPM` \ denom_arg -> - returnPM (rational_ty, mkConApp ratio_data_con [Type integer_ty, num_arg, denom_arg]) - where - (ratio_data_con, integer_ty) - = case (splitAlgTyConApp_maybe rational_ty) of - Just (tycon, [i_ty], [con]) - -> ASSERT(isIntegerTy i_ty && getUnique tycon == ratioTyConKey) - (con, i_ty) - - _ -> (panic "ratio_data_con", panic "integer_ty") - -litToRep other_lit = returnPM (literalType other_lit, mkLit other_lit) -\end{code} - - -%************************************************************************ -%* * -\subsection{The monad} -%* * -%************************************************************************ - -\begin{code} -type PostM a = Bool -- True <=> inside a *value* lambda - -> (UniqSupply, Bag CoreBind) -- Unique supply and Floats in - -> (a, (UniqSupply, Bag CoreBind)) - -initPM :: UniqSupply -> PostM a -> a -initPM us m - = case m False {- not inside lambda -} (us, emptyBag) of - (result, _) -> result - -returnPM v in_lam usf = (v, usf) -thenPM m k in_lam usf = case m in_lam usf of - (r, usf') -> k r in_lam usf' - -mapPM f [] = returnPM [] -mapPM f (x:xs) = f x `thenPM` \ r -> - mapPM f xs `thenPM` \ rs -> - returnPM (r:rs) - -insideLambda :: CoreBndr -> PostM a -> PostM a -insideLambda bndr m in_lam usf | isId bndr = m True usf - | otherwise = m in_lam usf - -getInsideLambda :: PostM Bool -getInsideLambda in_lam usf = (in_lam, usf) - -getFloatsPM :: PostM a -> PostM (a, Bag CoreBind) -getFloatsPM m in_lam (us, floats) - = let - (a, (us', floats')) = m in_lam (us, emptyBag) - in - ((a, floats'), (us', floats)) - -addTopFloat :: Type -> CoreExpr -> PostM Id -addTopFloat lit_ty lit_rhs in_lam (us, floats) - = let - (us1, us2) = splitUniqSupply us - uniq = uniqFromSupply us1 - lit_id = mkSysLocal SLIT("lf") uniq lit_ty - in - (lit_id, (us2, floats `snocBag` NonRec lit_id lit_rhs)) -\end{code} - -