X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FsimplCore%2FSimplCore.lhs;h=e21e0f0ae666ffea9d13f65c1fb2152cb4949499;hb=996573cd62a9dab5b3a7f7ab85567507422601bb;hp=2ada37315e570b49f2120efe3f038f70d280dac8;hpb=0596517a9b4b2b32e5d375a986351102ac4540fc;p=ghc-hetmet.git diff --git a/ghc/compiler/simplCore/SimplCore.lhs b/ghc/compiler/simplCore/SimplCore.lhs index 2ada373..e21e0f0 100644 --- a/ghc/compiler/simplCore/SimplCore.lhs +++ b/ghc/compiler/simplCore/SimplCore.lhs @@ -1,579 +1,713 @@ % -% (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 ) where -module SimplCore ( - core2core - ) where +#include "HsVersions.h" -import Type ( getTyConDataCons ) ---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 +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_dump_simpl, + 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, typeOkForCase ) +import CoreUnfold +import Literal ( Literal(..), literalType, mkMachInt ) +import ErrUtils ( ghcExit, dumpIfSet, doIfSet ) +import FiniteMap ( FiniteMap, emptyFM ) import FloatIn ( floatInwards ) import FloatOut ( floatOutwards ) -import Id ( getIdUnfolding, - idType, toplevelishId, - idWantsToBeINLINEd, - unfoldingUnfriendlyId, isWrapperId, - mkTemplateLocals +import FoldrBuildWW ( mkFoldrBuildWW ) +import Id ( mkSysLocal, mkUserId, setIdVisibility, replaceIdInfo, + replacePragmaInfo, getIdDemandInfo, idType, + getIdInfo, getPragmaInfo, mkIdWithNewUniq, + nullIdEnv, addOneToIdEnv, delOneFromIdEnv, + lookupIdEnv, IdEnv, + Id + ) +import IdInfo ( willBeDemanded, DemandInfo ) +import Name ( isExported, isLocallyDefined, + isLocalName, uniqToOccName, + setNameVisibility, + Module, NamedThing(..), OccName(..) ) -import IdInfo +import TyCon ( TyCon ) +import PrimOp ( PrimOp(..) ) +import PrelVals ( unpackCStringId, unpackCString2Id, + integerZeroId, integerPlusOneId, + integerPlusTwoId, integerMinusOneId + ) +import Type ( splitAlgTyConApp_maybe, isUnpointedType, Type ) +import TysWiredIn ( stringTy, isIntegerTy ) import LiberateCase ( liberateCase ) -import MainMonad -import Maybes +import MagicUFs ( MagicUnfoldingFun ) +import PprCore +import PprType ( GenType{-instance Outputable-}, GenTyVar{-ditto-}, + nmbrType + ) import SAT ( doStaticArgs ) -import SCCauto ---ANDY: ---import SimplHaskell ( coreToHaskell ) -import SimplMonad ( zeroSimplCount, showSimplCount, TickType, SimplCount ) +import SimplMonad ( zeroSimplCount, showSimplCount, SimplCount ) import SimplPgm ( simplifyPgm ) -import SimplVar ( leastItCouldCost ) import Specialise import SpecUtils ( pprSpecErrs ) import StrictAnal ( saWwTopBinds ) -import FoldrBuildWW -import AnalFBWW -#if ! OMIT_DEFORESTER -import Deforest ( deforestProgram ) -import DefUtils ( deforestable ) -#endif -import UniqSupply -import Util +import TyVar ( TyVar, nameTyVar ) +import Unique ( Unique{-instance Eq-}, Uniquable(..), + integerTyConKey, ratioTyConKey, + mkUnique, incrUnique, + initTidyUniques + ) +import UniqSupply ( UniqSupply, mkSplitUniqSupply, + splitUniqSupply, getUnique + ) +import UniqFM ( UniqFM, lookupUFM, addToUFM ) +import Util ( mapAccumL ) +import SrcLoc ( noSrcLoc ) +import Constants ( tARGET_MIN_INT, tARGET_MAX_INT ) +import Bag +import Maybes +import IO ( hPutStr, stderr ) +import Outputable \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) -> UniqSupply -- a name supply -> [TyCon] -- local data tycons and tycon specialisations - -> FiniteMap TyCon [(Bool, [Maybe Type])] -> [CoreBinding] -- input... - -> MainIO - ([CoreBinding], -- results: program, plus... - IdEnv UnfoldingDetails, -- unfoldings to be exported from here - 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) + -> IO [CoreBinding] -- results: program + +core2core core_todos module_name us local_tycons binds + = -- Do the main business + foldl_mn do_core_pass + (binds, us, zeroSimplCount) core_todos - `thenMn` \ (processed_binds, _, inline_env, spec_data, simpl_stats) -> - - (if switch_is_on D_simplifier_stats - then writeMn stderr ("\nSimplifier Stats:\n") - `thenMn_` - writeMn stderr (showSimplCount simpl_stats) - `thenMn_` - writeMn stderr "\n" - else returnMn () - ) `thenMn_` - - returnMn (processed_binds, inline_env, spec_data) - ESCC - where - init_specdata = initSpecData local_tycons tycon_specs + >>= \ (processed_binds, us', simpl_stats) -> - switch_is_on = switchIsOn sw_chkr + -- Do the final tidy-up + let + final_binds = tidyCorePgm module_name processed_binds + in + lintCoreBindings "TidyCorePgm" True final_binds >> - 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 + -- Dump output + dumpIfSet (opt_D_dump_simpl || opt_D_verbose_core2core) + "Core transformations" + (pprCoreBindings final_binds) >> - ------------- - core_linter = if switch_is_on DoCoreLinting - then lintCoreBindings ppr_style - else ( \ whodunnit spec_done binds -> binds ) + -- Report statistics + doIfSet opt_D_simplifier_stats + (hPutStr stderr ("\nSimplifier Stats:\n") >> + hPutStr stderr (showSimplCount simpl_stats) >> + hPutStr stderr "\n") >> + -- Return results + return final_binds + where -------------- - 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, simpl_stats) to_do = + case (splitUniqSupply us) of + (us1,us2) -> case to_do of CoreDoSimplify simpl_sw_chkr - -> BSCC("CoreSimplify") + -> _scc_ "CoreSimplify" begin_pass ("Simplify" ++ if switchIsOn simpl_sw_chkr SimplDoFoldrBuild - then " (foldr/build)" else "") `thenMn_` - case (simplifyPgm binds sw_chkr simpl_sw_chkr simpl_stats us1) of + then " (foldr/build)" else "") >> + case (simplifyPgm binds simpl_sw_chkr simpl_stats us1) of (p, it_cnt, simpl_stats2) - -> end_pass False us2 p inline_env spec_data simpl_stats2 + -> end_pass us2 p simpl_stats2 ("Simplify (" ++ show it_cnt ++ ")" ++ if switchIsOn simpl_sw_chkr SimplDoFoldrBuild then " foldr/build" else "") - ESCC CoreDoFoldrBuildWorkerWrapper - -> BSCC("CoreDoFoldrBuildWorkerWrapper") - begin_pass "FBWW" `thenMn_` - case (mkFoldrBuildWW switch_is_on us1 binds) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "FBWW" - } ESCC + -> _scc_ "CoreDoFoldrBuildWorkerWrapper" + begin_pass "FBWW" >> + case (mkFoldrBuildWW us1 binds) of { binds2 -> + end_pass us2 binds2 simpl_stats "FBWW" } CoreDoFoldrBuildWWAnal - -> BSCC("CoreDoFoldrBuildWWAnal") - begin_pass "AnalFBWW" `thenMn_` - case (analFBWW switch_is_on binds) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "AnalFBWW" - } ESCC + -> _scc_ "CoreDoFoldrBuildWWAnal" + begin_pass "AnalFBWW" >> + case (analFBWW binds) of { binds2 -> + end_pass us2 binds2 simpl_stats "AnalFBWW" } CoreLiberateCase - -> BSCC("LiberateCase") - begin_pass "LiberateCase" `thenMn_` - case (liberateCase lib_case_threshold binds) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "LiberateCase" - } ESCC - - CoreDoCalcInlinings1 -- avoid inlinings w/ cost-centres - -> BSCC("CoreInlinings1") - begin_pass "CalcInlinings" `thenMn_` - case (calcInlinings False sw_chkr inline_env binds) of { inline_env2 -> - end_pass False us2 binds inline_env2 spec_data simpl_stats "CalcInlinings" - } ESCC - - CoreDoCalcInlinings2 -- allow inlinings w/ cost-centres - -> BSCC("CoreInlinings2") - begin_pass "CalcInlinings" `thenMn_` - case (calcInlinings True sw_chkr inline_env binds) of { inline_env2 -> - end_pass False us2 binds inline_env2 spec_data simpl_stats "CalcInlinings" - } ESCC + -> _scc_ "LiberateCase" + begin_pass "LiberateCase" >> + case (liberateCase opt_LiberateCaseThreshold binds) of { binds2 -> + end_pass us2 binds2 simpl_stats "LiberateCase" } CoreDoFloatInwards - -> BSCC("FloatInwards") - begin_pass "FloatIn" `thenMn_` + -> _scc_ "FloatInwards" + begin_pass "FloatIn" >> case (floatInwards binds) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "FloatIn" - } ESCC + end_pass us2 binds2 simpl_stats "FloatIn" } CoreDoFullLaziness - -> BSCC("CoreFloating") - begin_pass "FloatOut" `thenMn_` - case (floatOutwards switch_is_on us1 binds) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "FloatOut" - } ESCC + -> _scc_ "CoreFloating" + begin_pass "FloatOut" >> + case (floatOutwards us1 binds) of { binds2 -> + end_pass us2 binds2 simpl_stats "FloatOut" } CoreDoStaticArgs - -> BSCC("CoreStaticArgs") - begin_pass "StaticArgs" `thenMn_` + -> _scc_ "CoreStaticArgs" + begin_pass "StaticArgs" >> case (doStaticArgs binds us1) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "StaticArgs" + end_pass us2 binds2 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") - begin_pass "StrAnal" `thenMn_` - case (saWwTopBinds us1 switch_is_on binds) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "StrAnal" - } ESCC + -> _scc_ "CoreStranal" + begin_pass "StrAnal" >> + case (saWwTopBinds us1 binds) of { binds2 -> + end_pass us2 binds2 simpl_stats "StrAnal" } CoreDoSpecialising - -> BSCC("Specialise") - begin_pass "Specialise" `thenMn_` - case (specProgram switch_is_on 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 module_name spec_errs spec_warn spec_tyerrs)) - `thenMn_` writeMn stderr "\n" - else - returnMn ()) `thenMn_` - - (if not spec_noerrs then -- Stop here if specialisation errors occured - exitMn 1 - else - returnMn ()) `thenMn_` - - end_pass False us2 p inline_env spec_data2 simpl_stats "Specialise" - } - ESCC - - CoreDoDeforest -#if OMIT_DEFORESTER - -> error "ERROR: CoreDoDeforest: not built into compiler\n" -#else - -> BSCC("Deforestation") - begin_pass "Deforestation" `thenMn_` - case (deforestProgram sw_chkr binds us1) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "Deforestation" + -> _scc_ "Specialise" + begin_pass "Specialise" >> + case (specProgram us1 binds) of { p -> + end_pass us2 p simpl_stats "Specialise" } - ESCC -#endif - - CoreDoAutoCostCentres - -> BSCC("AutoSCCs") - begin_pass "AutoSCCs" `thenMn_` - case (addAutoCostCentres sw_chkr module_name binds) of { binds2 -> - end_pass False us2 binds2 inline_env spec_data simpl_stats "AutoSCCs" - } - ESCC CoreDoPrintCore -- print result of last pass - -> end_pass True us2 binds inline_env spec_data simpl_stats "Print" - + -> dumpIfSet (not opt_D_verbose_core2core) "Print Core" + (pprCoreBindings binds) >> + return (binds, us1, simpl_stats) ------------------------------------------------- - begin_pass - = if switch_is_on D_show_passes - then \ what -> writeMn stderr ("*** Core2Core: "++what++"\n") - else \ what -> returnMn () + begin_pass what + = if opt_D_show_passes + then hPutStr stderr ("*** Core2Core: "++what++"\n") + else return () - end_pass print us2 binds2 inline_env2 - spec_data2@(SpecData spec_done _ _ _ _ _ _ _) + end_pass us2 binds2 simpl_stats2 what - = -- report verbosely, if required - (if (do_verbose_core2core && not print) || - (print && not do_verbose_core2core) - then - writeMn stderr ("\n*** "++what++":\n") - `thenMn_` - writeMn stderr (ppShow 1000 - (ppAboves (map (pprPlainCoreBinding ppr_style) binds2))) - `thenMn_` - writeMn stderr "\n" - else - returnMn ()) `thenMn_` - let - linted_binds = core_linter what spec_done binds2 - in - returnMn - (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 - ) + = -- Report verbosely, if required + dumpIfSet opt_D_verbose_core2core what + (pprCoreBindings binds2) >> + + lintCoreBindings what True {- spec_done -} binds2 >> + -- The spec_done flag tells the linter to + -- complain about unboxed let-bindings + -- But we're not specialising unboxed types any more, + -- so its irrelevant. + + return + (binds2, -- processed binds, possibly run thru CoreLint + us2, -- UniqSupply for the next guy + 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@ + +---------------- + [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 + +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.) + +8. Do let-to-case. See notes in Simplify.lhs for why we defer let-to-case + for multi-constructor types. + +9. Give all binders a nice print-name. Their uniques aren't changed; rather we give + them lexically unique occ-names, so that we can safely print the OccNae only + in the interface file. [Bad idea to change the uniques, because the code + generator makes global labels from the uniques for local thunks etc.] + -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 - -> [CoreBinding] - -> IdEnv UnfoldingDetails +tidyCorePgm :: Module -> [CoreBinding] -> [CoreBinding] + +tidyCorePgm mod binds_in + = initTM mod nullIdEnv $ + tidyTopBindings binds_in `thenTM` \ binds -> + returnTM (bagToList binds) +\end{code} + +Top level bindings +~~~~~~~~~~~~~~~~~~ +\begin{code} +tidyTopBindings [] = returnTM emptyBag +tidyTopBindings (b:bs) + = tidyTopBinding b $ + tidyTopBindings bs + +tidyTopBinding :: CoreBinding + -> TopTidyM (Bag CoreBinding) + -> TopTidyM (Bag CoreBinding) + +tidyTopBinding (NonRec bndr rhs) thing_inside + = initNestedTM (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' -> + initNestedTM (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} + + + +Expressions +~~~~~~~~~~~ +\begin{code} +tidyCoreExpr (Var v) = lookupId 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) + = tidyPrimOp prim `thenTM` \ prim' -> + mapTM tidyCoreArg args `thenTM` \ args' -> + returnTM (Prim prim' args') + +tidyCoreExpr (Lam (ValBinder v) body) + = newId v $ \ v' -> + tidyCoreExpr body `thenTM` \ body' -> + returnTM (Lam (ValBinder v') body') + +tidyCoreExpr (Lam (TyBinder tv) body) + = newTyVar tv $ \ tv' -> + tidyCoreExpr body `thenTM` \ body' -> + returnTM (Lam (TyBinder tv') body') + + -- Try for let-to-case (see notes in Simplify.lhs for why + -- some let-to-case stuff is deferred to now). +tidyCoreExpr (Let (NonRec bndr rhs) body) + | willBeDemanded (getIdDemandInfo bndr) && + not rhs_is_whnf && -- Don't do it if RHS is already in WHNF + typeOkForCase (idType bndr) + = ASSERT( not (isUnpointedType (idType bndr)) ) + tidyCoreExpr (Case rhs (AlgAlts [] (BindDefault bndr body))) + where + rhs_is_whnf = case mkFormSummary rhs of + VarForm -> True + ValueForm -> True + other -> False + +tidyCoreExpr (Let (NonRec bndr rhs) body) + = tidyCoreExpr rhs `thenTM` \ rhs' -> + newId bndr $ \ bndr' -> + tidyCoreExprEta body `thenTM` \ body' -> + returnTM (Let (NonRec bndr' rhs') body') + +tidyCoreExpr (Let (Rec pairs) body) + = newIds bndrs $ \ bndrs' -> + mapTM tidyCoreExpr rhss `thenTM` \ rhss' -> + tidyCoreExprEta body `thenTM` \ body' -> + returnTM (Let (Rec (bndrs' `zip` rhss')) body') + where + (bndrs, rhss) = unzip pairs + +tidyCoreExpr (SCC cc body) + = tidyCoreExprEta body `thenTM` \ body' -> + returnTM (SCC cc body') + +tidyCoreExpr (Coerce coercion ty body) + = tidyCoreExprEta body `thenTM` \ body' -> + tidyTy ty `thenTM` \ ty' -> + 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' -> + newId binder $ \ binder' -> + 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 (typeOkForCase (idType deflt_bndr)) + = pprTrace "Warning: discarding polymorphic case:" (ppr scrut) $ + case scrut of + Var v -> lookupId v `thenTM` \ 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) = newIds bndrs $ \ bndrs' -> + 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) + = newId bndr $ \ bndr' -> + 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 -> NestTidyM CoreArg + +tidyCoreArg (VarArg v) + = lookupId 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) = tidyTy ty `thenTM` \ ty' -> + returnTM (TyArg ty') +\end{code} + +\begin{code} +tidyPrimOp (CCallOp fn casm gc tys ty) + = mapTM tidyTy tys `thenTM` \ tys' -> + tidyTy ty `thenTM` \ ty' -> + returnTM (CCallOp fn casm gc tys' ty') + +tidyPrimOp other_prim_op = returnTM other_prim_op +\end{code} + -calcInlinings scc_s_OK sw_chkr inline_env_so_far top_binds +%************************************************************************ +%* * +\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 -> NestTidyM (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 (splitAlgTyConApp_maybe rational_ty) of + Just (tycon, [i_ty], [con]) + -> ASSERT(isIntegerTy i_ty && uniqueOf tycon == ratioTyConKey) + (con, i_ty) + + _ -> (panic "ratio_data_con", panic "integer_ty") + +litToRep other_lit = returnTM (literalType other_lit, Lit other_lit) +\end{code} + +\begin{code} +funnyParallelOp SeqOp = True +funnyParallelOp ParOp = True +funnyParallelOp ForkOp = True +funnyParallelOp _ = False +\end{code} + + +%************************************************************************ +%* * +\subsection{The monad} +%* * +%************************************************************************ + +\begin{code} +type TidyM a state = Module + -> UniqFM CoreBinder -- Maps Ids to Ids, TyVars to TyVars etc + -> state + -> (a, state) + +type TopTidyM a = TidyM a Unique +type NestTidyM a = TidyM a (Unique, -- Global names + Unique, -- Local names + Bag CoreBinding) -- Floats + + +(initialTopTidyUnique, initialNestedTidyUnique) = initTidyUniques + +initTM :: Module -> UniqFM CoreBinder -> TopTidyM a -> a +initTM mod env m + = case m mod env initialTopTidyUnique of + (result, _) -> result + +initNestedTM :: NestTidyM a -> TopTidyM (a, Bag CoreBinding) +initNestedTM m mod env global_us + = case m mod env (global_us, initialNestedTidyUnique, emptyBag) of + (result, (global_us', _, floats)) -> ((result, floats), global_us') + +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} +-- 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 -> TopTidyM a) -> TopTidyM a +mungeTopBinder id thing_inside mod env us + = case lookupIdEnv env id of + Just (ValBinder global) -> thing_inside global mod env us -- Already bound + + other -> -- Give it a new print-name unless it's an exported thing + -- setNameVisibility also does the local/global thing + let + (id', us') | isExported id = (id, us) + | otherwise + = (setIdVisibility (Just mod) us id, + incrUnique us) + + new_env = addToUFM env id (ValBinder id') + in + thing_inside id' mod new_env us' + +mungeTopBinders [] k = k [] +mungeTopBinders (b:bs) k = mungeTopBinder b $ \ b' -> + mungeTopBinders bs $ \ bs' -> + k (b' : bs') + +addTopFloat :: Type -> CoreExpr -> NestTidyM Id +addTopFloat lit_ty lit_rhs mod env (gus, lus, floats) = let - result = foldl calci inline_env_so_far top_binds + gus' = incrUnique gus + lit_local = mkSysLocal SLIT("lit") gus lit_ty noSrcLoc + lit_id = setIdVisibility (Just mod) gus lit_local in - --pprTrace "inline env:\n" (ppAboves (map pp_item (getIdEnvMapping result))) - result - 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 (GenForm _ _ 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 (Rec pairs) - = foldl (calc True{-recursive-}) inline_env pairs - - calci inline_env bind@(NonRec 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 - && (rhs_looks_like_a_caf || guidance_says_don't || guidance_size_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, - -- rhs_looks_like_a_caf, guidance_says_don't, guidance_size_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 - -- 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_size - = case guidance of - UnfoldAlways -> 0 -- *extremely* small - EssentialUnfolding -> 0 -- ditto - UnfoldIfGoodArgs _ _ _ size -> size - - guidance_says_don't = case guidance of { UnfoldNever -> True; _ -> False } - - guidance_size_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 - 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 then - False -- we'd like a top-level data constr to be - -- visible even if it is never unfolded - 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_looks_like_a_caf = not (manifestlyWHNF rhs) - - rhs_looks_like_a_data_val - = case (collectBinders rhs) of - (_, _, [], Con _ _ _) -> True - other -> False - - rhs_arg_tys - = case (collectBinders rhs) of - (_, _, val_binders, _) -> map idType val_binders - - (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! + (lit_id, (gus', lus, floats `snocBag` NonRec lit_id lit_rhs)) + +lookupId :: Id -> TidyM Id state +lookupId v mod env usf + = case lookupUFM env v of + Nothing -> (v, usf) + Just (ValBinder v') -> (v', usf) + +extendEnvTM :: Id -> Id -> (TidyM a state) -> TidyM a state +extendEnvTM v v' m mod env usf + = m mod (addOneToIdEnv env v (ValBinder v')) usf \end{code} -ANDY, on the hatred of the check above; why obliterate it? Consider - head xs = foldr (\ x _ -> x) (_|_) xs +Making new local binders +~~~~~~~~~~~~~~~~~~~~~~~~ +\begin{code} +newId id thing_inside mod env (gus, local_uniq, floats) + = let + -- Give the Id a fresh print-name, *and* rename its type + local_uniq' = incrUnique local_uniq + name' = setNameVisibility Nothing local_uniq (getName id) + ty' = nmbr_ty env local_uniq' (idType id) + id' = mkUserId name' ty' + -- NB: This throws away the IdInfo of the Id, which we + -- no longer need. That means we don't need to + -- run over it with env, nor renumber it + -- + -- NB: the Id's unique remains unchanged; it's only + -- its print name that is affected by local_uniq + + env' = addToUFM env id (ValBinder id') + in + thing_inside id' mod env' (gus, local_uniq', floats) + +newIds [] thing_inside + = thing_inside [] +newIds (bndr:bndrs) thing_inside + = newId bndr $ \ bndr' -> + newIds bndrs $ \ bndrs' -> + thing_inside (bndr' : bndrs') + + +newTyVar tyvar thing_inside mod env (gus, local_uniq, floats) + = let + local_uniq' = incrUnique local_uniq + tyvar' = nameTyVar tyvar (uniqToOccName local_uniq) + env' = addToUFM env tyvar (TyBinder tyvar') + in + thing_inside tyvar' mod env' (gus, local_uniq', floats) +\end{code} + +Re-numbering types +~~~~~~~~~~~~~~~~~~ +\begin{code} +tidyTy ty mod env usf@(_, local_uniq, _) + = (nmbr_ty env local_uniq ty, usf) + -- We can use local_uniq as a base for renaming forall'd variables + -- in the type; we don't need to know how many are consumed. + +-- This little impedance-matcher calls nmbrType with the right arguments +nmbr_ty env uniq ty + = nmbrType tv_env uniq ty + where + tv_env :: TyVar -> TyVar + tv_env tyvar = case lookupUFM env tyvar of + Just (TyBinder tyvar') -> tyvar' + other -> tyvar +\end{code} + -This then is exported via a pragma. However, -*if* you include the extra code above, you will -export the non-foldr/build version.