X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FsimplCore%2FSimplCore.lhs;h=787d1688e2582b10a0c8dc9845c07a051249dbcb;hb=1fb1ab5d53a09607e7f6d2450806760688396387;hp=69f53939f11e2b67334edf0ae5b8e08dbdf4a6d0;hpb=e7d21ee4f8ac907665a7e170c71d59e13a01da09;p=ghc-hetmet.git diff --git a/ghc/compiler/simplCore/SimplCore.lhs b/ghc/compiler/simplCore/SimplCore.lhs index 69f5393..787d168 100644 --- a/ghc/compiler/simplCore/SimplCore.lhs +++ b/ghc/compiler/simplCore/SimplCore.lhs @@ -1,602 +1,721 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1995 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 % \section[SimplCore]{Driver for simplifying @Core@ programs} \begin{code} #include "HsVersions.h" -module SimplCore ( - core2core, - - IdEnv(..), - UnfoldingDetails, - SpecialiseData(..), - UniqFM, Unique, Bag - ) where - -IMPORT_Trace -import Outputable -import Pretty - -import PlainCore - -import AbsUniType ( getTyConDataCons, alpha_ty, alpha_tyvar, beta_ty, beta_tyvar ) ---SAVE:import ArityAnal ( arityAnalProgram ) -import Bag -import BinderInfo ( BinderInfo) -- instances only -import CgCompInfo ( uNFOLDING_CREATION_THRESHOLD, - uNFOLDING_USE_THRESHOLD, - uNFOLDING_OVERRIDE_THRESHOLD, - uNFOLDING_CON_DISCOUNT_WEIGHT +module SimplCore ( core2core ) where + +IMP_Ubiq(){-uitous-} +IMPORT_1_3(IO(hPutStr,stderr)) + +import AnalFBWW ( analFBWW ) +import Bag ( isEmptyBag, foldBag ) +import BinderInfo ( BinderInfo{-instance Outputable-} ) +import CmdLineOpts ( CoreToDo(..), SimplifierSwitch(..), switchIsOn, + opt_D_show_passes, + opt_D_simplifier_stats, + opt_D_verbose_core2core, + opt_DoCoreLinting, + opt_FoldrBuildOn, + opt_ReportWhyUnfoldingsDisallowed, + opt_ShowImportSpecs, + opt_LiberateCaseThreshold ) -import CmdLineOpts import CoreLint ( lintCoreBindings ) +import CoreSyn +import CoreUtils ( coreExprType ) +import SimplUtils ( etaCoreExpr ) +import CoreUnfold +import Literal ( Literal(..), literalType, mkMachInt ) +import ErrUtils ( ghcExit ) +import FiniteMap ( FiniteMap ) import FloatIn ( floatInwards ) import FloatOut ( floatOutwards ) -import Id ( getIdUnfolding, - getIdUniType, toplevelishId, - idWantsToBeINLINEd, - unfoldingUnfriendlyId, isWrapperId, - mkTemplateLocals - IF_ATTACK_PRAGMAS(COMMA getIdStrictness) +import FoldrBuildWW ( mkFoldrBuildWW ) +import Id ( mkSysLocal, setIdVisibility, + nullIdEnv, addOneToIdEnv, delOneFromIdEnv, + lookupIdEnv, SYN_IE(IdEnv), + GenId{-instance Outputable-} + ) +import Name ( isExported, isLocallyDefined ) +import TyCon ( TyCon ) +import PrimOp ( PrimOp(..) ) +import PrelVals ( unpackCStringId, unpackCString2Id, + integerZeroId, integerPlusOneId, + integerPlusTwoId, integerMinusOneId ) -import IdEnv -import IdInfo +import Type ( maybeAppDataTyCon, getAppDataTyConExpandingDicts, maybeAppSpecDataTyConExpandingDicts ) +import TysWiredIn ( stringTy ) import LiberateCase ( liberateCase ) -import MainMonad -import Maybes +import MagicUFs ( MagicUnfoldingFun ) +import Outputable ( Outputable(..){-instance * (,) -} ) +import PprCore +import PprStyle ( PprStyle(..) ) +import PprType ( GenType{-instance Outputable-}, GenTyVar{-ditto-} ) +import Pretty ( ppShow, ppAboves, ppAbove, ppCat ) import SAT ( doStaticArgs ) -import SCCauto -import SimplEnv ( UnfoldingGuidance(..), SwitchChecker(..) ) -- instances ---ANDY: ---import SimplHaskell ( coreToHaskell ) -import SimplMonad ( zeroSimplCount, showSimplCount, TickType, SimplCount ) +import SimplMonad ( zeroSimplCount, showSimplCount, SimplCount ) import SimplPgm ( simplifyPgm ) -import SimplVar ( leastItCouldCost ) import Specialise -import SpecTyFuns ( pprSpecErrs ) +import SpecUtils ( pprSpecErrs ) import StrictAnal ( saWwTopBinds ) -#if ! OMIT_FOLDR_BUILD -import FoldrBuildWW -import AnalFBWW -#endif -#if ! OMIT_DEFORESTER +import TyVar ( nullTyVarEnv, GenTyVar{-instance Eq-} ) +import Unique ( integerTyConKey, ratioTyConKey, Unique{-instance Eq-} ) +import UniqSupply ( splitUniqSupply, getUnique ) +import Util ( mapAccumL, assertPanic, panic{-ToDo:rm-}, pprTrace, pprPanic ) +import SrcLoc ( noSrcLoc ) +import Constants ( tARGET_MIN_INT, tARGET_MAX_INT ) +import Bag +import Maybes + + +#ifndef OMIT_DEFORESTER import Deforest ( deforestProgram ) import DefUtils ( deforestable ) #endif -import TyVarEnv ( nullTyVarEnv ) -import SplitUniq -import Unique -import Util + \end{code} \begin{code} core2core :: [CoreToDo] -- spec of what core-to-core passes to do - -> (GlobalSwitch->SwitchResult)-- "global" command-line info lookup fn -> FAST_STRING -- module name (profiling only) -> PprStyle -- printing style (for debugging only) - -> SplitUniqSupply -- a name supply + -> UniqSupply -- a name supply -> [TyCon] -- local data tycons and tycon specialisations - -> FiniteMap TyCon [[Maybe UniType]] - -> [PlainCoreBinding] -- input... - -> MainIO - ([PlainCoreBinding], -- results: program, plus... - IdEnv UnfoldingDetails, -- unfoldings to be exported from here + -> FiniteMap TyCon [(Bool, [Maybe Type])] + -> [CoreBinding] -- input... + -> IO + ([CoreBinding], -- results: program, plus... SpecialiseData) -- specialisation data -core2core core_todos sw_chkr module_name ppr_style us local_tycons tycon_specs binds - = BSCC("Core2Core") - if null core_todos then -- very rare, I suspect... - -- well, we still must do some renumbering - returnMn ( - (snd (instCoreBindings (mkUniqueSupplyGrimily us) binds), nullIdEnv, init_specdata) - ) - else - (if do_verbose_core2core then - writeMn stderr "VERBOSE CORE-TO-CORE:\n" - else returnMn ()) `thenMn_` - - -- better do the main business - foldl_mn do_core_pass - (binds, us, nullIdEnv, init_specdata, zeroSimplCount) +core2core core_todos module_name ppr_style us local_tycons tycon_specs binds + = -- Print heading + (if opt_D_verbose_core2core then + hPutStr stderr "VERBOSE CORE-TO-CORE:\n" + else return ()) >> + + -- Do the main business + --case (splitUniqSupply us) of { (us1,us2) -> + foldl_mn do_core_pass + (binds, us, init_specdata, zeroSimplCount) core_todos - `thenMn` \ (processed_binds, _, inline_env, spec_data, simpl_stats) -> - - (if switch_is_on D_simplifier_stats - then trace ("Simplifier Stats:\n" ++ showSimplCount simpl_stats) (returnMn ()) - else returnMn () - ) `thenMn_` - -{- LATER: - (if do_dump_core_passes - then trace (unlines ( - (nOfThem 78 '-' - : "Core2Core" - : "+------------------------------+" - : reverse [ " " ++ take (30::Int) (what ++ repeat ' ') ++ "|" - | what <- simpl_whats ]) - ++ ["+------------------------------+"])) - else \x -> x) -- to the end --} - returnMn (processed_binds, inline_env, spec_data) - ESCC + >>= \ (processed_binds, us', spec_data, simpl_stats) -> + + -- Do the final tidy-up + let + final_binds = core_linter "TidyCorePgm" True $ + tidyCorePgm module_name us' processed_binds + in + + -- Report statistics + (if opt_D_simplifier_stats then + hPutStr stderr ("\nSimplifier Stats:\n") >> + hPutStr stderr (showSimplCount simpl_stats) >> + hPutStr stderr "\n" + else return ()) >> + + -- + return (final_binds, spec_data) --} where +-- (us1, us2) = splitUniqSupply us init_specdata = initSpecData local_tycons tycon_specs - switch_is_on = switchIsOn sw_chkr - - do_dump_core_passes = switch_is_on D_dump_core_passes -- an Andy flag - do_verbose_core2core = switch_is_on D_verbose_core2core - - lib_case_threshold -- ToDo: HACK HACK HACK : FIX ME FIX ME FIX ME - -- Use 4x a known threshold - = case (intSwitchSet sw_chkr UnfoldingOverrideThreshold) of - Nothing -> 4 * uNFOLDING_USE_THRESHOLD - Just xx -> 4 * xx - ------------- - core_linter = if switch_is_on DoCoreLinting - then lintCoreBindings ppr_style - else ( \ whodunnit spec_done binds -> binds ) + core_linter what spec_done + = if opt_DoCoreLinting + then (if opt_D_show_passes then + trace ("\n*** Core Lint result of " ++ what) + else id + ) + lintCoreBindings ppr_style what spec_done + else id -------------- - do_core_pass info@(binds, us, inline_env, spec_data, simpl_stats) to_do - = let - (us1, us2) = splitUniqSupply us - in + do_core_pass info@(binds, us, spec_data, simpl_stats) to_do = +-- let +-- (us1, us2) = splitUniqSupply us +-- in + case (splitUniqSupply us) of + (us1,us2) -> case to_do of CoreDoSimplify simpl_sw_chkr - -> BSCC("CoreSimplify") - case (simplifyPgm binds sw_chkr simpl_sw_chkr simpl_stats us1) of + -> _scc_ "CoreSimplify" + begin_pass ("Simplify" ++ if switchIsOn simpl_sw_chkr SimplDoFoldrBuild + then " (foldr/build)" else "") >> + case (simplifyPgm binds simpl_sw_chkr simpl_stats us1) of (p, it_cnt, simpl_stats2) - -> end_pass us2 p inline_env spec_data simpl_stats2 ("Simplify (" ++ show it_cnt ++ ")") - ESCC + -> end_pass False us2 p spec_data simpl_stats2 + ("Simplify (" ++ show it_cnt ++ ")" + ++ if switchIsOn simpl_sw_chkr SimplDoFoldrBuild + then " foldr/build" else "") CoreDoFoldrBuildWorkerWrapper -#if OMIT_FOLDR_BUILD - -> error "ERROR: CoreDoFoldrBuildWorkerWrapper: not built into compiler\n" -#else - -> BSCC("CoreDoFoldrBuildWorkerWrapper") - end_pass us2 (mkFoldrBuildWW switch_is_on us1 binds) inline_env spec_data simpl_stats "FBWW" - ESCC -#endif + -> _scc_ "CoreDoFoldrBuildWorkerWrapper" + begin_pass "FBWW" >> + case (mkFoldrBuildWW us1 binds) of { binds2 -> + end_pass False us2 binds2 spec_data simpl_stats "FBWW" } CoreDoFoldrBuildWWAnal -#if OMIT_FOLDR_BUILD - -> error "ERROR: CoreDoFoldrBuildWWAnal: not built into compiler\n" -#else - -> BSCC("CoreDoFoldrBuildWWAnal") - end_pass us2 (analFBWW switch_is_on binds) inline_env spec_data simpl_stats "AnalFBWW" - ESCC -#endif + -> _scc_ "CoreDoFoldrBuildWWAnal" + begin_pass "AnalFBWW" >> + case (analFBWW binds) of { binds2 -> + end_pass False us2 binds2 spec_data simpl_stats "AnalFBWW" } CoreLiberateCase - -> BSCC("LiberateCase") - case (liberateCase lib_case_threshold binds) of { binds2 -> - end_pass us2 binds2 inline_env spec_data simpl_stats "LiberateCase" - } - ESCC - - CoreDoCalcInlinings1 -- avoid inlinings w/ cost-centres - -> BSCC("CoreInlinings1") - case (calcInlinings False sw_chkr inline_env binds) of { inline_env2 -> - end_pass us2 binds inline_env2 spec_data simpl_stats "Calc Inlinings" - } ESCC - - CoreDoCalcInlinings2 -- allow inlinings w/ cost-centres - -> BSCC("CoreInlinings2") - case (calcInlinings True sw_chkr inline_env binds) of { inline_env2 -> - end_pass us2 binds inline_env2 spec_data simpl_stats "Calc Inlinings" - } ESCC + -> _scc_ "LiberateCase" + begin_pass "LiberateCase" >> + case (liberateCase opt_LiberateCaseThreshold binds) of { binds2 -> + end_pass False us2 binds2 spec_data simpl_stats "LiberateCase" } CoreDoFloatInwards - -> BSCC("FloatInwards") - end_pass us2 (floatInwards binds) inline_env spec_data simpl_stats "FloatIn" - ESCC + -> _scc_ "FloatInwards" + begin_pass "FloatIn" >> + case (floatInwards binds) of { binds2 -> + end_pass False us2 binds2 spec_data simpl_stats "FloatIn" } CoreDoFullLaziness - -> BSCC("CoreFloating") - case (floatOutwards switch_is_on us1 binds) of { p -> - end_pass us2 p inline_env spec_data simpl_stats "FloatOut" - } ESCC - - CoreDoPrintCore -> - let - printed = ppShow 80 (ppr ppr_style binds) - strict [] a = a - strict (s:ss) a | ord s == 0 = error "0 in output string" - | otherwise = strict ss a - in - end_pass us2 (strict printed (trace ("PrintCore:\n" ++ printed) binds)) inline_env spec_data simpl_stats "Print" - -{- ANDY: - CoreDoHaskPrint -> - let - printed = coreToHaskell binds - strict [] a = a - strict (s:ss) a | ord s == 0 = error "0 in output string" - | otherwise = strict ss a - in - strict printed (trace ("PrintCore:\n" ++ printed) binds), inline_env, spec_data, simpl_stats, "PrintHask" --} + -> _scc_ "CoreFloating" + begin_pass "FloatOut" >> + case (floatOutwards us1 binds) of { binds2 -> + end_pass False us2 binds2 spec_data simpl_stats "FloatOut" } CoreDoStaticArgs - -> BSCC("CoreStaticArgs") - end_pass us2 (doStaticArgs binds us1) inline_env spec_data simpl_stats "SAT" + -> _scc_ "CoreStaticArgs" + begin_pass "StaticArgs" >> + case (doStaticArgs binds us1) of { binds2 -> + end_pass False us2 binds2 spec_data simpl_stats "StaticArgs" } -- Binds really should be dependency-analysed for static- -- arg transformation... Not to worry, they probably are. -- (I don't think it *dies* if they aren't [WDP 94/04/15]) - ESCC CoreDoStrictness - -> BSCC("CoreStranal") - end_pass us2 (saWwTopBinds us1 switch_is_on binds) inline_env spec_data simpl_stats "StrAnal" - ESCC + -> _scc_ "CoreStranal" + begin_pass "StrAnal" >> + case (saWwTopBinds us1 binds) of { binds2 -> + end_pass False us2 binds2 spec_data simpl_stats "StrAnal" } CoreDoSpecialising - -> BSCC("Specialise") - case (specProgram switch_is_on us1 binds spec_data) of { + -> _scc_ "Specialise" + begin_pass "Specialise" >> + case (specProgram us1 binds spec_data) of { (p, spec_data2@(SpecData _ spec_noerrs _ _ _ spec_errs spec_warn spec_tyerrs)) -> -- if we got errors, we die straight away - (if not spec_noerrs || - (switch_is_on ShowImportSpecs && not (isEmptyBag spec_warn)) then - writeMn stderr (ppShow 1000 {-pprCols-} - (pprSpecErrs PprForUser spec_errs spec_warn spec_tyerrs)) - `thenMn_` writeMn stderr "\n" + (if not spec_noerrs || + (opt_ShowImportSpecs && not (isEmptyBag spec_warn)) then + hPutStr stderr (ppShow 1000 {-pprCols-} + (pprSpecErrs module_name spec_errs spec_warn spec_tyerrs)) + >> hPutStr stderr "\n" else - returnMn ()) `thenMn_` + return ()) >> (if not spec_noerrs then -- Stop here if specialisation errors occured - exitMn 1 + ghcExit 1 else - returnMn ()) `thenMn_` + return ()) >> - end_pass us2 p inline_env spec_data2 simpl_stats "Specialise" + end_pass False us2 p spec_data2 simpl_stats "Specialise" } - ESCC - CoreDoDeforest + CoreDoDeforest #if OMIT_DEFORESTER -> error "ERROR: CoreDoDeforest: not built into compiler\n" #else - -> BSCC("Deforestation") - case (deforestProgram sw_chkr binds us1) of { binds -> - end_pass us2 binds inline_env spec_data simpl_stats "Deforestation" - } - ESCC + -> _scc_ "Deforestation" + begin_pass "Deforestation" >> + case (deforestProgram binds us1) of { binds2 -> + end_pass False us2 binds2 spec_data simpl_stats "Deforestation" } #endif - - CoreDoAutoCostCentres - -> BSCC("AutoSCCs") - end_pass us2 (addAutoCostCentres sw_chkr module_name binds) inline_env spec_data simpl_stats "AutoSCCs" - ESCC + + CoreDoPrintCore -- print result of last pass + -> end_pass True us2 binds spec_data simpl_stats "Print" ------------------------------------------------- - end_pass us2 binds2 inline_env2 + begin_pass + = if opt_D_show_passes + then \ what -> hPutStr stderr ("*** Core2Core: "++what++"\n") + else \ what -> return () + + end_pass print us2 binds2 spec_data2@(SpecData spec_done _ _ _ _ _ _ _) simpl_stats2 what = -- report verbosely, if required - (if do_verbose_core2core then - writeMn stderr ("\n*** "++what++":\n") - `thenMn_` - writeMn stderr (ppShow 1000 - (ppAboves (map (pprPlainCoreBinding ppr_style) binds2))) - `thenMn_` - writeMn stderr "\n" + (if (opt_D_verbose_core2core && not print) || + (print && not opt_D_verbose_core2core) + then + hPutStr stderr ("\n*** "++what++":\n") + >> + hPutStr stderr (ppShow 1000 + (ppAboves (map (pprCoreBinding ppr_style) binds2))) + >> + hPutStr stderr "\n" else - returnMn ()) `thenMn_` + return ()) >> let linted_binds = core_linter what spec_done binds2 in - returnMn + return (linted_binds, -- processed binds, possibly run thru CoreLint us2, -- UniqueSupply for the next guy - inline_env2, -- possibly-updated inline env spec_data2, -- possibly-updated specialisation info simpl_stats2 -- accumulated simplifier stats ) -- here so it can be inlined... -foldl_mn f z [] = returnMn z -foldl_mn f z (x:xs) = f z x `thenMn` \ zz -> - foldl_mn f zz xs +foldl_mn f z [] = return z +foldl_mn f z (x:xs) = f z x >>= \ zz -> + foldl_mn f zz xs \end{code} ---- ToDo: maybe move elsewhere --- -For top-level, exported binders that either (a)~have been INLINEd by -the programmer or (b)~are sufficiently ``simple'' that they should be -inlined, we want to record this info in a suitable IdEnv. -But: if something has a ``wrapper unfolding,'' we do NOT automatically -give it a regular unfolding (exception below). We usually assume its -worker will get a ``regular'' unfolding. We can then treat these two -levels of unfolding separately (we tend to be very friendly towards -wrapper unfoldings, for example), giving more fine-tuned control. +%************************************************************************ +%* * +\subsection[SimplCore-indirections]{Eliminating indirections in Core code, and globalising} +%* * +%************************************************************************ + +Several tasks are done by @tidyCorePgm@ + +1. Eliminate indirections. The point here is to transform + x_local = E + x_exported = x_local + ==> + x_exported = E + +2. Make certain top-level bindings into Globals. The point is that + Global things get externally-visible labels at code generation + time + +3. Make the representation of NoRep literals explicit, and + float their bindings to the top level + +4. Convert + case x of {...; x' -> ...x'...} + ==> + case x of {...; _ -> ...x... } + See notes in SimplCase.lhs, near simplDefault for the reasoning here. + +5. *Mangle* cases involving fork# and par# in the discriminant. The + original templates for these primops (see @PrelVals.lhs@) constructed + case expressions with boolean results solely to fool the strictness + analyzer, the simplifier, and anyone else who might want to fool with + the evaluation order. At this point in the compiler our evaluation + order is safe. Therefore, we convert expressions of the form: + + case par# e of + True -> rhs + False -> parError# + ==> + case par# e of + _ -> rhs + +6. Eliminate polymorphic case expressions. We can't generate code for them yet. + +7. 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.) + + +Eliminate indirections +~~~~~~~~~~~~~~~~~~~~~~ +In @elimIndirections@, we look for things at the top-level of the form... +\begin{verbatim} + x_local = .... + x_exported = x_local +\end{verbatim} +In cases we find like this, we go {\em backwards} and replace +\tr{x_local} with \tr{x_exported}. This save a gratuitous jump +(from \tr{x_exported} to \tr{x_local}), and makes strictness +information propagate better. + +We rely on prior eta reduction to simplify things like +\begin{verbatim} + x_exported = /\ tyvars -> x_local tyvars +==> + x_exported = x_local +\end{verbatim} + +If more than one exported thing is equal to a local thing (i.e., the +local thing really is shared), then we do one only: +\begin{verbatim} + x_local = .... + x_exported1 = x_local + x_exported2 = x_local +==> + x_exported1 = .... + + x_exported2 = x_exported1 +\end{verbatim} + +There's a possibility of leaving unchanged something like this: +\begin{verbatim} + x_local = .... + x_exported1 = x_local Int +\end{verbatim} +By the time we've thrown away the types in STG land this +could be eliminated. But I don't think it's very common +and it's dangerous to do this fiddling in STG land +because we might elminate a binding that's mentioned in the +unfolding for something. + +General Strategy: first collect the info; then make a \tr{Id -> Id} mapping. +Then blast the whole program (LHSs as well as RHSs) with it. -The exception is: If the ``regular unfolding'' mentions no other -global Ids (i.e., it's all PrimOps and cases and local Ids) then we -assume it must be really good and we take it anyway. -We also need to check that everything in the RHS (values and types) -will be visible on the other side of an interface, too. \begin{code} -calcInlinings :: Bool -- True => inlinings with _scc_s are OK - -> (GlobalSwitch -> SwitchResult) - -> IdEnv UnfoldingDetails - -> [PlainCoreBinding] - -> IdEnv UnfoldingDetails - -calcInlinings scc_s_OK sw_chkr inline_env_so_far top_binds - = let - result = foldl calci inline_env_so_far top_binds - in - --pprTrace "inline env:\n" (ppAboves (map pp_item (getIdEnvMapping result))) - result +tidyCorePgm :: Module -> UniqSupply -> [CoreBinding] -> [CoreBinding] + +tidyCorePgm mod us binds_in + = initTM mod indirection_env us $ + tidyTopBindings (catMaybes reduced_binds) `thenTM` \ binds -> + returnTM (bagToList binds) where - pp_item (binder, details) - = ppCat [ppr PprDebug binder, ppStr "=>", pp_det details] - where - pp_det NoUnfoldingDetails = ppStr "_N_" - pp_det (IWantToBeINLINEd _) = ppStr "INLINE" - pp_det (GeneralForm _ _ expr guide) - = ppAbove (ppr PprDebug guide) (ppr PprDebug expr) - pp_det other = ppStr "???" - - ------------ - switch_is_on = switchIsOn sw_chkr - - my_trace = if (switch_is_on ReportWhyUnfoldingsDisallowed) - then trace - else \ msg stuff -> stuff - - (unfolding_creation_threshold, explicit_creation_threshold) - = case (intSwitchSet sw_chkr UnfoldingCreationThreshold) of - Nothing -> (uNFOLDING_CREATION_THRESHOLD, False) - Just xx -> (xx, True) - - unfold_use_threshold - = case (intSwitchSet sw_chkr UnfoldingUseThreshold) of - Nothing -> uNFOLDING_USE_THRESHOLD - Just xx -> xx - - unfold_override_threshold - = case (intSwitchSet sw_chkr UnfoldingOverrideThreshold) of - Nothing -> uNFOLDING_OVERRIDE_THRESHOLD - Just xx -> xx - - con_discount_weight = uNFOLDING_CON_DISCOUNT_WEIGHT - - calci inline_env (CoRec pairs) - = foldl (calc True{-recursive-}) inline_env pairs - - calci inline_env bind@(CoNonRec binder rhs) - = calc False{-not recursive-} inline_env (binder, rhs) - - --------------------------------------- - - calc is_recursive inline_env (binder, rhs) - | not (toplevelishId binder) - = --pprTrace "giving up on not top-level:" (ppr PprDebug binder) - ignominious_defeat - - | rhs_mentions_an_unmentionable - || (not explicit_INLINE_requested - && (guidance_says_don't || guidance_size_just_too_big)) - = let - my_my_trace - = if explicit_INLINE_requested - && not (isWrapperId binder) -- these always claim to be INLINEd - && not have_inlining_already - then trace -- we'd better have a look... - else my_trace - - which = if scc_s_OK then " (late):" else " (early):" - in - --pprTrace "giving up on size:" (ppCat [ppr PprDebug binder, ppr PprDebug [rhs_mentions_an_unmentionable, explicit_INLINE_requested, guidance_says_don't, guidance_size_just_too_big]]) ( - my_my_trace ("unfolding disallowed for"++which++(ppShow 80 (ppr PprDebug binder))) ( - ignominious_defeat - ) - --) - - | rhs `isWrapperFor` binder - -- Don't add an explicit "unfolding"; let the worker/wrapper - -- stuff do its thing. INLINE things don't get w/w'd, so - -- they will be OK. - = --pprTrace "giving up on isWrapperFor:" (ppr PprDebug binder) - ignominious_defeat - -#if ! OMIT_DEFORESTER - -- For the deforester: bypass the barbed wire for recursive - -- functions that want to be inlined and are tagged deforestable - -- by the user, allowing these things to be communicated - -- across module boundaries. - - | is_recursive && - explicit_INLINE_requested && - deforestable binder && - scc_s_OK -- hack, only get them in - -- calc_inlinings2 - = glorious_success UnfoldAlways -#endif - - | is_recursive && not rhs_looks_like_a_data_val_to_me - -- The only recursive defns we are prepared to tolerate at the - -- moment is top-level very-obviously-a-data-value ones. - -- We *need* these for dictionaries to be exported! - = --pprTrace "giving up on rec:" (ppr PprDebug binder) - ignominious_defeat - - -- Not really interested unless it's exported, but doing it - -- this way (not worrying about export-ness) gets us all the - -- workers/specs, etc., too; which we will need for generating - -- interfaces. We are also not interested if this binder is - -- in the environment we already have (perhaps from a previous - -- run of calcInlinings -- "earlier" is presumed to mean - -- "better"). - - | explicit_INLINE_requested - = glorious_success UnfoldAlways - - | otherwise - = glorious_success guidance - - where - guidance - = calcUnfoldingGuidance scc_s_OK max_out_threshold rhs - where - max_out_threshold = if explicit_INLINE_requested - then 100000 -- you asked for it, you got it - else unfolding_creation_threshold - - guidance_says_don't = case guidance of { UnfoldNever -> True; _ -> False } - - guidance_size - = case guidance of - UnfoldAlways -> 0 -- *extremely* small - EssentialUnfolding -> 0 -- ditto - UnfoldIfGoodArgs _ _ _ size -> size - - guidance_size_just_too_big - -- Does the guidance suggest that this unfolding will - -- be of no use *no matter* the arguments given to it? - -- Could be more sophisticated... - = case guidance of - UnfoldNever -> False -- debugging only (ToDo:rm) - UnfoldAlways -> False - EssentialUnfolding -> False - UnfoldIfGoodArgs _ no_val_args arg_info_vec size - - -> if explicit_creation_threshold then - False -- user set threshold; don't second-guess... - - else if no_val_args == 0 && rhs_looks_like_a_data_val_to_me then - False -- probably a data value; we'd like the - -- other guy to see the value, even if - -- s/he doesn't unfold it. - else - let - cost - = leastItCouldCost con_discount_weight size no_val_args - arg_info_vec rhs_arg_tys - in --- (if (unfold_use_threshold < cost) then (pprTrace "cost:" (ppInt cost)) else \x->x ) ( - unfold_use_threshold < cost --- ) - - - rhs_arg_tys - = let - (_, val_binders, _) = digForLambdas rhs - in - map getIdUniType val_binders - - rhs_looks_like_a_data_val_to_me - = let - (_,val_binders,body) = digForLambdas rhs - in - case (val_binders, body) of - ([], CoCon _ _ _) -> True - other -> False - - (mentioned_ids, _, _, mentions_litlit) - = mentionedInUnfolding (\x -> x) rhs - - rhs_mentions_an_unmentionable - = --pprTrace "mentions:" (ppCat [ppr PprDebug binder, ppr PprDebug [(i,unfoldingUnfriendlyId i) | i <- mentioned_ids ]]) ( - any unfoldingUnfriendlyId mentioned_ids - || mentions_litlit - --) - -- ToDo: probably need to chk tycons/classes... - - mentions_no_other_ids = null mentioned_ids - - explicit_INLINE_requested - -- did it come from a user {-# INLINE ... #-}? - -- (Warning: must avoid including wrappers.) - = idWantsToBeINLINEd binder - && not (rhs `isWrapperFor` binder) - - have_inlining_already = maybeToBool (lookupIdEnv inline_env binder) - - ignominious_defeat = inline_env -- just give back what we got - - {- - "glorious_success" is ours if we've found a suitable unfolding. - - But we check for a couple of fine points. - - (1) If this Id already has an inlining in the inline_env, - we don't automatically take it -- the earlier one is - "likely" to be better. - - But if the new one doesn't mention any other global - Ids, and it's pretty small (< UnfoldingOverrideThreshold), - then we take the chance that the new one *is* better. - - (2) If we have an Id w/ a worker/wrapper split (with - an unfolding for the wrapper), we tend to want to keep - it -- and *nuke* any inlining that we conjured up - earlier. - - But, again, if this unfolding doesn't mention any - other global Ids (and small enough), then it is - probably better than the worker/wrappery, so we take - it. - -} - glorious_success guidance - = let - new_env = addOneToIdEnv inline_env binder (mkUnfolding guidance rhs) - - foldr_building = switch_is_on FoldrBuildOn - in - if (not have_inlining_already) then - -- Not in env: we take it no matter what - -- NB: we could check for worker/wrapper-ness, - -- but the truth is we probably haven't run - -- the strictness analyser yet. - new_env - - else if explicit_INLINE_requested then - -- If it was a user INLINE, then we know it's already - -- in the inline_env; we stick with what we already - -- have. - --pprTrace "giving up on INLINE:" (ppr PprDebug binder) - ignominious_defeat - - else if isWrapperId binder then - -- It's in the env, but we have since worker-wrapperised; - -- we either take this new one (because it's so good), - -- or we *undo* the one in the inline_env, so the - -- wrapper-inlining will take over. - - if mentions_no_other_ids {- *** && size <= unfold_override_threshold -} then - new_env - else - delOneFromIdEnv inline_env binder - - else - -- It's in the env, nothing to do w/ worker wrapper; - -- we'll take it if it is better. - - if not foldr_building -- ANDY hates us... (see below) - && mentions_no_other_ids - && guidance_size <= unfold_override_threshold then - new_env - else - --pprTrace "giving up on final hurdle:" (ppCat [ppr PprDebug binder, ppInt guidance_size, ppInt unfold_override_threshold]) - ignominious_defeat -- and at the last hurdle, too! + (indirection_env, reduced_binds) = mapAccumL try_bind nullIdEnv binds_in + + try_bind :: IdEnv Id -> CoreBinding -> (IdEnv Id, Maybe CoreBinding) + try_bind env_so_far + (NonRec exported_binder (Var local_id)) + | isExported exported_binder && -- Only if this is exported + isLocallyDefined local_id && -- Only if this one is defined in this + not (isExported local_id) && -- module, so that we *can* change its + -- binding to be the exported thing! + not (maybeToBool (lookupIdEnv env_so_far local_id)) + -- Only if not already substituted for + = (addOneToIdEnv env_so_far local_id exported_binder, Nothing) + + try_bind env_so_far bind + = (env_so_far, Just bind) +\end{code} + +Top level bindings +~~~~~~~~~~~~~~~~~~ +\begin{code} +tidyTopBindings [] = returnTM emptyBag +tidyTopBindings (b:bs) + = tidyTopBinding b $ + tidyTopBindings bs + +tidyTopBinding :: CoreBinding + -> TidyM (Bag CoreBinding) + -> TidyM (Bag CoreBinding) + +tidyTopBinding (NonRec bndr rhs) thing_inside + = getFloats (tidyCoreExpr rhs) `thenTM` \ (rhs',floats) -> + mungeTopBinder bndr $ \ bndr' -> + thing_inside `thenTM` \ binds -> + returnTM ((floats `snocBag` NonRec bndr' rhs') `unionBags` binds) + +tidyTopBinding (Rec pairs) thing_inside + = mungeTopBinders binders $ \ binders' -> + getFloats (mapTM tidyCoreExpr rhss) `thenTM` \ (rhss', floats) -> + thing_inside `thenTM` \ binds_inside -> + returnTM ((floats `snocBag` Rec (binders' `zip` rhss')) `unionBags` binds_inside) + where + (binders, rhss) = unzip pairs +\end{code} + + +Local Bindings +~~~~~~~~~~~~~~ +\begin{code} +tidyCoreBinding (NonRec bndr rhs) + = tidyCoreExpr rhs `thenTM` \ rhs' -> + returnTM (NonRec bndr rhs') + +tidyCoreBinding (Rec pairs) + = mapTM do_one pairs `thenTM` \ pairs' -> + returnTM (Rec pairs') + where + do_one (bndr,rhs) = tidyCoreExpr rhs `thenTM` \ rhs' -> + returnTM (bndr, rhs') + +\end{code} + + +Expressions +~~~~~~~~~~~ +\begin{code} +tidyCoreExpr (Var v) = lookupTM v `thenTM` \ v' -> + returnTM (Var v') + +tidyCoreExpr (Lit lit) + = litToRep lit `thenTM` \ (_, lit_expr) -> + returnTM lit_expr + +tidyCoreExpr (App fun arg) + = tidyCoreExpr fun `thenTM` \ fun' -> + tidyCoreArg arg `thenTM` \ arg' -> + returnTM (App fun' arg') + +tidyCoreExpr (Con con args) + = mapTM tidyCoreArg args `thenTM` \ args' -> + returnTM (Con con args') + +tidyCoreExpr (Prim prim args) + = mapTM tidyCoreArg args `thenTM` \ args' -> + returnTM (Prim prim args') + +tidyCoreExpr (Lam bndr body) + = tidyCoreExpr body `thenTM` \ body' -> + returnTM (Lam bndr body') + +tidyCoreExpr (Let bind body) + = tidyCoreBinding bind `thenTM` \ bind' -> + tidyCoreExprEta body `thenTM` \ body' -> + returnTM (Let bind' body') + +tidyCoreExpr (SCC cc body) + = tidyCoreExprEta body `thenTM` \ body' -> + returnTM (SCC cc body') + +tidyCoreExpr (Coerce coercion ty body) + = tidyCoreExprEta body `thenTM` \ body' -> + returnTM (Coerce coercion ty body') + +-- Wierd case for par, seq, fork etc. See notes above. +tidyCoreExpr (Case scrut@(Prim op args) (PrimAlts _ (BindDefault binder rhs))) + | funnyParallelOp op + = tidyCoreExpr scrut `thenTM` \ scrut' -> + tidyCoreExprEta rhs `thenTM` \ rhs' -> + returnTM (Case scrut' (PrimAlts [] (BindDefault binder rhs'))) + +-- Eliminate polymorphic case, for which we can't generate code just yet +tidyCoreExpr (Case scrut (AlgAlts [] (BindDefault deflt_bndr rhs))) + | not (maybeToBool (maybeAppSpecDataTyConExpandingDicts (coreExprType scrut))) + = pprTrace "Warning: discarding polymorphic case:" (ppr PprDebug scrut) $ + case scrut of + Var v -> extendEnvTM deflt_bndr v (tidyCoreExpr rhs) + other -> tidyCoreExpr (Let (NonRec deflt_bndr scrut) rhs) + +tidyCoreExpr (Case scrut alts) + = tidyCoreExpr scrut `thenTM` \ scrut' -> + tidy_alts scrut' alts `thenTM` \ alts' -> + returnTM (Case scrut' alts') + where + tidy_alts scrut (AlgAlts alts deflt) + = mapTM tidy_alg_alt alts `thenTM` \ alts' -> + tidy_deflt scrut deflt `thenTM` \ deflt' -> + returnTM (AlgAlts alts' deflt') + + tidy_alts scrut (PrimAlts alts deflt) + = mapTM tidy_prim_alt alts `thenTM` \ alts' -> + tidy_deflt scrut deflt `thenTM` \ deflt' -> + returnTM (PrimAlts alts' deflt') + + tidy_alg_alt (con,bndrs,rhs) = tidyCoreExprEta rhs `thenTM` \ rhs' -> + returnTM (con,bndrs,rhs') + + tidy_prim_alt (lit,rhs) = tidyCoreExprEta rhs `thenTM` \ rhs' -> + returnTM (lit,rhs') + + -- We convert case x of {...; x' -> ...x'...} + -- to + -- case x of {...; _ -> ...x... } + -- + -- See notes in SimplCase.lhs, near simplDefault for the reasoning. + -- It's quite easily done: simply extend the environment to bind the + -- default binder to the scrutinee. + + tidy_deflt scrut NoDefault = returnTM NoDefault + tidy_deflt scrut (BindDefault bndr rhs) + = extend_env (tidyCoreExprEta rhs) `thenTM` \ rhs' -> + returnTM (BindDefault bndr rhs') + where + extend_env = case scrut of + Var v -> extendEnvTM bndr v + other -> \x -> x + +tidyCoreExprEta e = tidyCoreExpr e `thenTM` \ e' -> + returnTM (etaCoreExpr e') +\end{code} + +Arguments +~~~~~~~~~ +\begin{code} +tidyCoreArg :: CoreArg -> TidyM CoreArg + +tidyCoreArg (VarArg v) + = lookupTM v `thenTM` \ v' -> + returnTM (VarArg v') + +tidyCoreArg (LitArg lit) + = litToRep lit `thenTM` \ (lit_ty, lit_expr) -> + case lit_expr of + Var v -> returnTM (VarArg v) + Lit l -> returnTM (LitArg l) + other -> addTopFloat lit_ty lit_expr `thenTM` \ v -> + returnTM (VarArg v) + +tidyCoreArg (TyArg ty) = returnTM (TyArg ty) +tidyCoreArg (UsageArg u) = returnTM (UsageArg u) +\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 -> TidyM (Type, CoreExpr) + +litToRep (NoRepStr s) + = returnTM (stringTy, rhs) + where + rhs = if (any is_NUL (_UNPK_ s)) + + then -- Must cater for NULs in literal string + mkGenApp (Var unpackCString2Id) + [LitArg (MachStr s), + LitArg (mkMachInt (toInteger (_LENGTH_ s)))] + + else -- No NULs in the string + App (Var unpackCStringId) (LitArg (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 @litString2Integer@. + +\begin{code} +litToRep (NoRepInteger i integer_ty) + = returnTM (integer_ty, rhs) + where + rhs | i == 0 = Var integerZeroId -- Extremely convenient to look out for + | i == 1 = Var integerPlusOneId -- a few very common Integer literals! + | i == 2 = Var integerPlusTwoId + | i == (-1) = Var integerMinusOneId + + | i > tARGET_MIN_INT && -- Small enough, so start from an Int + i < tARGET_MAX_INT + = Prim Int2IntegerOp [LitArg (mkMachInt i)] + + | otherwise -- Big, so start from a string + = Prim Addr2IntegerOp [LitArg (MachStr (_PK_ (show i)))] + + +litToRep (NoRepRational r rational_ty) + = tidyCoreArg (LitArg (NoRepInteger (numerator r) integer_ty)) `thenTM` \ num_arg -> + tidyCoreArg (LitArg (NoRepInteger (denominator r) integer_ty)) `thenTM` \ denom_arg -> + returnTM (rational_ty, Con ratio_data_con [TyArg integer_ty, num_arg, denom_arg]) + where + (ratio_data_con, integer_ty) + = case (maybeAppDataTyCon rational_ty) of + Just (tycon, [i_ty], [con]) + -> ASSERT(is_integer_ty i_ty && uniqueOf tycon == ratioTyConKey) + (con, i_ty) + + _ -> (panic "ratio_data_con", panic "integer_ty") + + is_integer_ty ty + = case (maybeAppDataTyCon ty) of + Just (tycon, [], _) -> uniqueOf tycon == integerTyConKey + _ -> False + +litToRep other_lit = returnTM (literalType other_lit, Lit other_lit) \end{code} -ANDY, on the hatred of the check above; why obliterate it? Consider +\begin{code} +funnyParallelOp SeqOp = True +funnyParallelOp ParOp = True +funnyParallelOp ForkOp = True +funnyParallelOp _ = False +\end{code} + + +%************************************************************************ +%* * +\subsection{The monad} +%* * +%************************************************************************ + +\begin{code} +type TidyM a = Module + -> IdEnv Id + -> (UniqSupply, Bag CoreBinding) + -> (a, (UniqSupply, Bag CoreBinding)) + +initTM mod env us m + = case m mod env (us,emptyBag) of + (result, (us',floats)) -> result + +returnTM v mod env usf = (v, usf) +thenTM m k mod env usf = case m mod env usf of + (r, usf') -> k r mod env usf' + +mapTM f [] = returnTM [] +mapTM f (x:xs) = f x `thenTM` \ r -> + mapTM f xs `thenTM` \ rs -> + returnTM (r:rs) +\end{code} + + +\begin{code} +getFloats :: TidyM a -> TidyM (a, Bag CoreBinding) +getFloats m mod env (us,floats) + = case m mod env (us,emptyBag) of + (r, (us',floats')) -> ((r, floats'), (us',floats)) + + +-- Need to extend the environment when we munge a binder, so that occurrences +-- of the binder will print the correct way (i.e. as a global not a local) +mungeTopBinder :: Id -> (Id -> TidyM a) -> TidyM a +mungeTopBinder id thing_inside mod env usf + = case lookupIdEnv env id of + Just global -> thing_inside global mod env usf + Nothing -> thing_inside new_global mod new_env usf + where + new_env = addOneToIdEnv env id new_global + new_global = setIdVisibility mod id + +mungeTopBinders [] k = k [] +mungeTopBinders (b:bs) k = mungeTopBinder b $ \ b' -> + mungeTopBinders bs $ \ bs' -> + k (b' : bs') + +addTopFloat :: Type -> CoreExpr -> TidyM Id +addTopFloat lit_ty lit_rhs mod env (us, floats) + = case splitUniqSupply us of + (us',us1) -> + let + lit_local = mkSysLocal SLIT("nrlit") uniq lit_ty noSrcLoc + lit_id = setIdVisibility mod lit_local + --(us', us1) = splitUniqSupply us + uniq = getUnique us1 + in + (lit_id, (us', floats `snocBag` NonRec lit_id lit_rhs)) +{- + where + lit_local = mkSysLocal SLIT("nrlit") uniq lit_ty noSrcLoc + lit_id = setIdVisibility mod lit_local + (us', us1) = splitUniqSupply us + uniq = getUnique us1 +-} +lookupTM v mod env usf + = case lookupIdEnv env v of + Nothing -> (v, usf) + Just v' -> (v', usf) + +extendEnvTM v v' m mod env usf + = m mod (addOneToIdEnv env v v') usf +\end{code} - head xs = foldr (\ x _ -> x) (_|_) xs -This then is exported via a pragma. However, -*if* you include the extra code above, you will -export the non-foldr/build version.