X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FsimplCore%2FSimplCore.lhs;h=541f38a5408e2978d91c6ad7f7af0a542afd04b9;hb=f714e6b642fd614a9971717045ae47c3d871275e;hp=ff7749e7057607f6a06b6c7e24b7b26477edf7e4;hpb=940841711bb0c30326a5173d8107c2792919641c;p=ghc-hetmet.git diff --git a/ghc/compiler/simplCore/SimplCore.lhs b/ghc/compiler/simplCore/SimplCore.lhs index ff7749e..541f38a 100644 --- a/ghc/compiler/simplCore/SimplCore.lhs +++ b/ghc/compiler/simplCore/SimplCore.lhs @@ -4,70 +4,51 @@ \section[SimplCore]{Driver for simplifying @Core@ programs} \begin{code} -module SimplCore ( core2core ) where +module SimplCore ( core2core, simplifyExpr ) where #include "HsVersions.h" -import CmdLineOpts ( CoreToDo(..), SimplifierSwitch(..), - SwitchResult(..), switchIsOn, intSwitchSet, - opt_D_dump_occur_anal, opt_D_dump_rules, - opt_D_dump_simpl_iterations, - opt_D_dump_simpl_stats, - opt_D_dump_simpl, opt_D_dump_rules, - opt_D_verbose_core2core, - opt_D_dump_occur_anal, - opt_UsageSPOn, +import CmdLineOpts ( CoreToDo(..), SimplifierSwitch(..), + SimplifierMode(..), DynFlags, DynFlag(..), dopt, + dopt_CoreToDo, buildCoreToDo ) -import CoreLint ( beginPass, endPass ) import CoreSyn +import TcIface ( loadImportedRules ) +import HscTypes ( HscEnv(..), ModGuts(..), ModGuts, + ModDetails(..), HomeModInfo(..) ) import CSE ( cseProgram ) -import Rules ( RuleBase, ProtoCoreRule(..), pprProtoCoreRule, prepareRuleBase, orphanRule ) -import CoreUnfold -import PprCore ( pprCoreBindings ) -import OccurAnal ( occurAnalyseBinds ) -import CoreUtils ( exprIsTrivial, etaReduceExpr ) +import Rules ( RuleBase, ruleBaseIds, + extendRuleBaseList, pprRuleBase, getLocalRules, + ruleCheckProgram ) +import Module ( moduleEnvElts ) +import PprCore ( pprCoreBindings, pprCoreExpr, pprIdRules ) +import OccurAnal ( occurAnalyseBinds, occurAnalyseGlobalExpr ) +import CoreUtils ( coreBindsSize ) import Simplify ( simplTopBinds, simplExpr ) -import SimplUtils ( findDefault, simplBinders ) +import SimplUtils ( simplBinders ) import SimplMonad -import Literal ( Literal(..), literalType, mkMachInt ) -import ErrUtils ( dumpIfSet ) +import ErrUtils ( dumpIfSet, dumpIfSet_dyn, showPass ) +import CoreLint ( endPass ) import FloatIn ( floatInwards ) import FloatOut ( floatOutwards ) -import Id ( Id, mkSysLocal, mkVanillaId, isBottomingId, isDataConWrapId, - idType, setIdType, idName, idInfo, setIdNoDiscard - ) -import VarEnv +import Id ( idIsFrom, idSpecialisation, setIdSpecialisation ) import VarSet -import Module ( Module ) -import Name ( mkLocalName, tidyOccName, tidyTopName, - NamedThing(..), OccName - ) -import TyCon ( TyCon, isDataTyCon ) -import PrelRules ( builtinRules ) -import Type ( Type, - isUnLiftedType, - tidyType, tidyTypes, tidyTopType, tidyTyVar, tidyTyVars, - Type - ) -import TysWiredIn ( smallIntegerDataCon, isIntegerTy ) import LiberateCase ( liberateCase ) import SAT ( doStaticArgs ) import Specialise ( specProgram) -import UsageSPInf ( doUsageSPInf ) -import StrictAnal ( saBinds ) +import SpecConstr ( specConstrProgram) +import DmdAnal ( dmdAnalPgm ) import WorkWrap ( wwTopBinds ) +#ifdef OLD_STRICTNESS +import StrictAnal ( saBinds ) import CprAnalyse ( cprAnalyse ) +#endif -import Unique ( Unique, Uniquable(..) ) -import UniqSupply ( UniqSupply, mkSplitUniqSupply, splitUniqSupply, uniqFromSupply ) -import Util ( mapAccumL ) -import SrcLoc ( noSrcLoc ) -import Bag -import Maybes +import UniqSupply ( UniqSupply, mkSplitUniqSupply, splitUniqSupply ) import IO ( hPutStr, stderr ) import Outputable -import Ratio ( numerator, denominator ) +import Maybes ( orElse ) \end{code} %************************************************************************ @@ -77,128 +58,306 @@ import Ratio ( numerator, denominator ) %************************************************************************ \begin{code} -core2core :: [CoreToDo] -- Spec of what core-to-core passes to do - -> [CoreBind] -- Binds in - -> [ProtoCoreRule] -- Rules - -> IO ([CoreBind], [ProtoCoreRule]) +core2core :: HscEnv + -> ModGuts + -> IO ModGuts -core2core core_todos binds rules +core2core hsc_env + mod_impl@(ModGuts { mg_binds = binds_in }) = do - us <- mkSplitUniqSupply 's' - let (cp_us, us1) = splitUniqSupply us - (ru_us, ps_us) = splitUniqSupply us1 + let dflags = hsc_dflags hsc_env + core_todos + | Just todo <- dopt_CoreToDo dflags = todo + | otherwise = buildCoreToDo dflags - better_rules <- simplRules ru_us rules binds + us <- mkSplitUniqSupply 's' + let (cp_us, ru_us) = splitUniqSupply us - let all_rules = builtinRules ++ better_rules - -- Here is where we add in the built-in rules + -- COMPUTE THE RULE BASE TO USE + (rule_base, local_rule_ids, orphan_rules) + <- prepareRules hsc_env mod_impl ru_us - let (binds1, rule_base) = prepareRuleBase binds all_rules + -- PREPARE THE BINDINGS + let binds1 = updateBinders local_rule_ids binds_in - -- Do the main business - (stats, processed_binds) <- doCorePasses zeroSimplCount cp_us binds1 - rule_base core_todos + -- DO THE BUSINESS + (stats, processed_binds) + <- doCorePasses dflags rule_base (zeroSimplCount dflags) cp_us binds1 core_todos - dumpIfSet opt_D_dump_simpl_stats + dumpIfSet_dyn dflags Opt_D_dump_simpl_stats "Grand total simplifier statistics" (pprSimplCount stats) -- Return results - return (processed_binds, filter orphanRule better_rules) - + -- We only return local orphan rules, i.e., local rules not attached to an Id + -- The bindings cotain more rules, embedded in the Ids + return (mod_impl { mg_binds = processed_binds, mg_rules = orphan_rules}) + + +simplifyExpr :: DynFlags -- includes spec of what core-to-core passes to do + -> CoreExpr + -> IO CoreExpr +-- simplifyExpr is called by the driver to simplify an +-- expression typed in at the interactive prompt +simplifyExpr dflags expr + = do { + ; showPass dflags "Simplify" + + ; us <- mkSplitUniqSupply 's' + + ; let env = emptySimplEnv SimplGently [] emptyVarSet + (expr', _counts) = initSmpl dflags us (simplExprGently env expr) + + ; dumpIfSet_dyn dflags Opt_D_dump_simpl "Simplified expression" + (pprCoreExpr expr') + + ; return expr' + } + -doCorePasses stats us binds irs [] +doCorePasses :: DynFlags + -> RuleBase -- the main rule base + -> SimplCount -- simplifier stats + -> UniqSupply -- uniques + -> [CoreBind] -- local binds in (with rules attached) + -> [CoreToDo] -- which passes to do + -> IO (SimplCount, [CoreBind]) -- stats, binds, local orphan rules + +doCorePasses dflags rb stats us binds [] = return (stats, binds) -doCorePasses stats us binds irs (to_do : to_dos) +doCorePasses dflags rb stats us binds (to_do : to_dos) = do - let (us1, us2) = splitUniqSupply us - (stats1, binds1) <- doCorePass us1 binds irs to_do - doCorePasses (stats `plusSimplCount` stats1) us2 binds1 irs to_dos - -doCorePass us binds rb (CoreDoSimplify sw_chkr) = _scc_ "Simplify" simplifyPgm rb sw_chkr us binds -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 (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) -doCorePass us binds rb CoreDoSpecialising = _scc_ "Specialise" noStats (specProgram us binds) -doCorePass us binds rb CoreDoCPResult = _scc_ "CPResult" noStats (cprAnalyse binds) -doCorePass us binds rb CoreDoPrintCore = _scc_ "PrintCore" noStats (printCore binds) -doCorePass us binds rb CoreDoUSPInf - = _scc_ "CoreUsageSPInf" - if opt_UsageSPOn then - noStats (doUsageSPInf us binds) - else - trace "WARNING: ignoring requested -fusagesp pass; requires -fusagesp-on" $ - noStats (return binds) + let (us1, us2) = splitUniqSupply us + + (stats1, binds1) <- doCorePass dflags rb us1 binds to_do + + doCorePasses dflags rb (stats `plusSimplCount` stats1) us2 binds1 to_dos + +doCorePass dfs rb us binds (CoreDoSimplify mode switches) + = _scc_ "Simplify" simplifyPgm dfs rb mode switches us binds +doCorePass dfs rb us binds CoreCSE + = _scc_ "CommonSubExpr" noStats dfs (cseProgram dfs binds) +doCorePass dfs rb us binds CoreLiberateCase + = _scc_ "LiberateCase" noStats dfs (liberateCase dfs binds) +doCorePass dfs rb us binds CoreDoFloatInwards + = _scc_ "FloatInwards" noStats dfs (floatInwards dfs binds) +doCorePass dfs rb us binds (CoreDoFloatOutwards f) + = _scc_ "FloatOutwards" noStats dfs (floatOutwards dfs f us binds) +doCorePass dfs rb us binds CoreDoStaticArgs + = _scc_ "StaticArgs" noStats dfs (doStaticArgs us binds) +doCorePass dfs rb us binds CoreDoStrictness + = _scc_ "Stranal" noStats dfs (dmdAnalPgm dfs binds) +doCorePass dfs rb us binds CoreDoWorkerWrapper + = _scc_ "WorkWrap" noStats dfs (wwTopBinds dfs us binds) +doCorePass dfs rb us binds CoreDoSpecialising + = _scc_ "Specialise" noStats dfs (specProgram dfs us binds) +doCorePass dfs rb us binds CoreDoSpecConstr + = _scc_ "SpecConstr" noStats dfs (specConstrProgram dfs us binds) +#ifdef OLD_STRICTNESS +doCorePass dfs rb us binds CoreDoOldStrictness + = _scc_ "OldStrictness" noStats dfs (doOldStrictness dfs binds) +#endif +doCorePass dfs rb us binds CoreDoPrintCore + = _scc_ "PrintCore" noStats dfs (printCore binds) +doCorePass dfs rb us binds CoreDoGlomBinds + = noStats dfs (glomBinds dfs binds) +doCorePass dfs rb us binds (CoreDoRuleCheck phase pat) + = noStats dfs (ruleCheck dfs phase pat binds) +doCorePass dfs rb us binds CoreDoNothing + = noStats dfs (return binds) + +#ifdef OLD_STRICTNESS +doOldStrictness dfs binds + = do binds1 <- saBinds dfs binds + binds2 <- cprAnalyse dfs binds1 + return binds2 +#endif printCore binds = do dumpIfSet True "Print Core" (pprCoreBindings binds) return binds -noStats thing = do { result <- thing; return (zeroSimplCount, result) } +ruleCheck dflags phase pat binds = do showPass dflags "RuleCheck" + printDump (ruleCheckProgram phase pat binds) + return binds + +-- most passes return no stats and don't change rules +noStats dfs thing = do { binds <- thing; return (zeroSimplCount dfs, binds) } + \end{code} + %************************************************************************ %* * \subsection{Dealing with rules} %* * %************************************************************************ -We must do some gentle simplifiation on the template (but not the RHS) +-- prepareLocalRuleBase takes the CoreBinds and rules defined in this module. +-- It attaches those rules that are for local Ids to their binders, and +-- returns the remainder attached to Ids in an IdSet. It also returns +-- Ids mentioned on LHS of some rule; these should be blacklisted. + +-- The rule Ids and LHS Ids are black-listed; that is, they aren't inlined +-- so that the opportunity to apply the rule isn't lost too soon + +\begin{code} +prepareRules :: HscEnv + -> ModGuts + -> UniqSupply + -> IO (RuleBase, -- Full rule base + IdSet, -- Local rule Ids + [IdCoreRule]) -- Orphan rules defined in this module + +prepareRules hsc_env@(HscEnv { hsc_dflags = dflags, hsc_HPT = hpt }) + guts@(ModGuts { mg_binds = binds, mg_rules = local_rules, mg_module = this_mod }) + us + = do { pkg_rule_base <- loadImportedRules hsc_env guts + + ; let env = emptySimplEnv SimplGently [] local_ids + (better_rules,_) = initSmpl dflags us (mapSmpl (simplRule env) local_rules) + + imp_rule_base = foldl add_rules pkg_rule_base (moduleEnvElts hpt) + full_rule_base = extendRuleBaseList imp_rule_base better_rules + + (local_rule_ids, final_rule_base) = getLocalRules this_mod full_rule_base + -- NB: the imported rules may include rules for Ids in this module + -- which is why we suck the local rules out of full_rule_base + + orphan_rules = filter (not . idIsFrom this_mod . fst) better_rules + + ; dumpIfSet_dyn dflags Opt_D_dump_rules "Transformation rules" + (vcat [text "Local rules", pprIdRules better_rules, + text "", + text "Imported rules", pprRuleBase final_rule_base]) + + ; return (final_rule_base, local_rule_ids, orphan_rules) + } + where + add_rules rule_base mod_info = extendRuleBaseList rule_base (md_rules (hm_details mod_info)) + + -- Boringly, we need to gather the in-scope set. + local_ids = foldr (unionVarSet . mkVarSet . bindersOf) emptyVarSet binds + + +updateBinders :: IdSet -- Locally defined ids with their Rules attached + -> [CoreBind] -> [CoreBind] + -- A horrible function + +-- Update the binders of top-level bindings by +-- attaching the rules for each locally-defined Id to that Id. +-- +-- Reason +-- - It makes the rules easier to look up +-- - It means that transformation rules and specialisations for +-- locally defined Ids are handled uniformly +-- - It keeps alive things that are referred to only from a rule +-- (the occurrence analyser knows about rules attached to Ids) +-- - It makes sure that, when we apply a rule, the free vars +-- of the RHS are more likely to be in scope + +updateBinders rule_ids binds + = map update_bndrs binds + where + update_bndrs (NonRec b r) = NonRec (update_bndr b) r + update_bndrs (Rec prs) = Rec [(update_bndr b, r) | (b,r) <- prs] + + update_bndr bndr = case lookupVarSet rule_ids bndr of + Nothing -> bndr + Just id -> bndr `setIdSpecialisation` idSpecialisation id +\end{code} + + +We must do some gentle simplification on the template (but not the RHS) of each rule. The case that forced me to add this was the fold/build rule, which without simplification looked like: fold k z (build (/\a. g a)) ==> ... This doesn't match unless you do eta reduction on the build argument. \begin{code} -simplRules :: UniqSupply -> [ProtoCoreRule] -> [CoreBind] -> IO [ProtoCoreRule] -simplRules us rules binds - = do let (better_rules,_) = initSmpl sw_chkr us bind_vars black_list_all (mapSmpl simplRule rules) - - dumpIfSet opt_D_dump_rules - "Transformation rules" - (vcat (map pprProtoCoreRule better_rules)) - - return better_rules - where - 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 - -- simpVar fails if it isn't right, and it might conceivably matter - bind_vars = foldr (unionVarSet . mkVarSet . bindersOf) emptyVarSet binds - - -simplRule rule@(ProtoCoreRule is_local id (Rule name bndrs args rhs)) - | not is_local - = returnSmpl rule -- No need to fiddle with imported rules - | otherwise - = simplBinders bndrs $ \ bndrs' -> - 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 +simplRule env rule@(id, BuiltinRule _ _) + = returnSmpl rule +simplRule env rule@(id, Rule act name bndrs args rhs) + = simplBinders env bndrs `thenSmpl` \ (env, bndrs') -> + mapSmpl (simplExprGently env) args `thenSmpl` \ args' -> + simplExprGently env rhs `thenSmpl` \ rhs' -> + returnSmpl (id, Rule act name bndrs' args' rhs') + +-- It's important that simplExprGently does eta reduction. +-- For example, in a rule like: -- augment g (build h) --- turns into +-- we do not want to get -- 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 +-- otherwise we don't match when given an argument like -- (\a. h a a) - = simplExpr e `thenSmpl` \ e' -> - returnSmpl (etaReduceExpr e') +-- +-- The simplifier does indeed do eta reduction (it's in +-- Simplify.completeLam) but only if -O is on. \end{code} +\begin{code} +simplExprGently :: SimplEnv -> CoreExpr -> SimplM CoreExpr +-- Simplifies an expression +-- does occurrence analysis, then simplification +-- and repeats (twice currently) because one pass +-- alone leaves tons of crud. +-- Used (a) for user expressions typed in at the interactive prompt +-- (b) the LHS and RHS of a RULE +-- +-- The name 'Gently' suggests that the SimplifierMode is SimplGently, +-- and in fact that is so.... but the 'Gently' in simplExprGently doesn't +-- enforce that; it just simplifies the expression twice + +simplExprGently env expr + = simplExpr env (occurAnalyseGlobalExpr expr) `thenSmpl` \ expr1 -> + simplExpr env (occurAnalyseGlobalExpr expr1) +\end{code} + + +%************************************************************************ +%* * +\subsection{Glomming} +%* * +%************************************************************************ + +\begin{code} +glomBinds :: DynFlags -> [CoreBind] -> IO [CoreBind] +-- Glom all binds together in one Rec, in case any +-- transformations have introduced any new dependencies +-- +-- NB: the global invariant is this: +-- *** the top level bindings are never cloned, and are always unique *** +-- +-- We sort them into dependency order, but applying transformation rules may +-- make something at the top refer to something at the bottom: +-- f = \x -> p (q x) +-- h = \y -> 3 +-- +-- RULE: p (q x) = h x +-- +-- Applying this rule makes f refer to h, +-- although it doesn't appear to in the source program. +-- This pass lets us control where it happens. +-- +-- NOTICE that this cannot happen for rules whose head is a locally-defined +-- function. It only happens for rules whose head is an imported function +-- (p in the example above). So, for example, the rule had been +-- RULE: f (p x) = h x +-- then the rule for f would be attached to f itself (in its IdInfo) +-- by prepareLocalRuleBase and h would be regarded by the occurrency +-- analyser as free in f. + +glomBinds dflags binds + = do { showPass dflags "GlomBinds" ; + let { recd_binds = [Rec (flattenBinds binds)] } ; + return recd_binds } + -- Not much point in printing the result... + -- just consumes output bandwidth +\end{code} + + %************************************************************************ %* * \subsection{The driver for the simplifier} @@ -206,76 +365,94 @@ simpl_arg e %************************************************************************ \begin{code} -simplifyPgm :: RuleBase - -> (SimplifierSwitch -> SwitchResult) +simplifyPgm :: DynFlags + -> RuleBase + -> SimplifierMode + -> [SimplifierSwitch] -> UniqSupply - -> [CoreBind] -- Input - -> IO (SimplCount, [CoreBind]) -- New bindings + -> [CoreBind] -- Input + -> IO (SimplCount, [CoreBind]) -- New bindings -simplifyPgm (imported_rule_ids, rule_lhs_fvs) - sw_chkr us binds +simplifyPgm dflags rule_base + mode switches us binds = do { - beginPass "Simplify"; - - -- Glom all binds together in one Rec, in case any - -- transformations have introduced any new dependencies - -- - -- NB: the global invariant is this: - -- *** the top level bindings are never cloned, and are always unique *** - -- - -- We sort them into dependency order, but applying transformation rules may - -- make something at the top refer to something at the bottom: - -- f = \x -> p (q x) - -- h = \y -> 3 - -- - -- RULE: p (q x) = h x - -- - -- Applying this rule makes f refer to h, although it doesn't appear to in the - -- source program. Our solution is to do this occasional glom-together step, - -- just once per overall simplfication step. - - let { recd_binds = [Rec (flattenBinds binds)] }; - - (termination_msg, it_count, counts_out, binds') <- iteration us 1 zeroSimplCount recd_binds; - - dumpIfSet (opt_D_verbose_core2core && opt_D_dump_simpl_stats) + showPass dflags "Simplify"; + + (termination_msg, it_count, counts_out, binds') + <- iteration us 1 (zeroSimplCount dflags) binds; + + dumpIfSet (dopt Opt_D_verbose_core2core dflags + && dopt Opt_D_dump_simpl_stats dflags) "Simplifier statistics" (vcat [text termination_msg <+> text "after" <+> ppr it_count <+> text "iterations", text "", pprSimplCount counts_out]); - endPass "Simplify" - (opt_D_verbose_core2core && not opt_D_dump_simpl_iterations) - binds' ; + endPass dflags "Simplify" Opt_D_verbose_core2core binds'; return (counts_out, binds') } where - max_iterations = getSimplIntSwitch sw_chkr MaxSimplifierIterations - black_list_fn = blackListed rule_lhs_fvs (intSwitchSet sw_chkr SimplInlinePhase) - - core_iter_dump binds | opt_D_verbose_core2core = pprCoreBindings binds - | otherwise = empty - + phase_info = case mode of + SimplGently -> "gentle" + SimplPhase n -> show n + + imported_rule_ids = ruleBaseIds rule_base + simpl_env = emptySimplEnv mode switches imported_rule_ids + sw_chkr = getSwitchChecker simpl_env + max_iterations = intSwitchSet sw_chkr MaxSimplifierIterations `orElse` 2 + iteration us iteration_no counts binds + -- iteration_no is the number of the iteration we are + -- about to begin, with '1' for the first + | iteration_no > max_iterations -- Stop if we've run out of iterations + = do { +#ifdef DEBUG + if max_iterations > 2 then + hPutStr stderr ("NOTE: Simplifier still going after " ++ + show max_iterations ++ + " iterations; bailing out.\n") + else + return (); +#endif + -- Subtract 1 from iteration_no to get the + -- number of iterations we actually completed + return ("Simplifier baled out", iteration_no - 1, counts, binds) + } + + -- Try and force thunks off the binds; significantly reduces + -- space usage, especially with -O. JRS, 000620. + | let sz = coreBindsSize binds in sz == sz = do { -- Occurrence analysis let { tagged_binds = _scc_ "OccAnal" occurAnalyseBinds binds } ; - dumpIfSet opt_D_dump_occur_anal "Occurrence analysis" + dumpIfSet_dyn dflags Opt_D_dump_occur_anal "Occurrence analysis" (pprCoreBindings tagged_binds); - -- Simplify - let { (binds', counts') = initSmpl sw_chkr us1 imported_rule_ids - black_list_fn - (simplTopBinds tagged_binds); + -- SIMPLIFY + -- We do this with a *case* not a *let* because lazy pattern + -- matching bit us with bad space leak! + -- With a let, we ended up with + -- let + -- t = initSmpl ... + -- counts' = snd t + -- in + -- case t of {(_,counts') -> if counts'=0 then ... } + -- So the conditional didn't force counts', because the + -- selection got duplicated. Sigh! + case initSmpl dflags us1 (simplTopBinds simpl_env tagged_binds) of { + (binds', counts') -> do { -- The imported_rule_ids are used by initSmpl to initialise -- the in-scope set. That way, the simplifier will change any -- occurrences of the imported id to the one in the imported_rule_ids -- set, which are decorated with their rules. - all_counts = counts `plusSimplCount` counts' - } ; + let { all_counts = counts `plusSimplCount` counts' ; + herald = "Simplifier phase " ++ phase_info ++ + ", iteration " ++ show iteration_no ++ + " out of " ++ show max_iterations + } ; -- Stop if nothing happened; don't dump output if isZeroSimplCount counts' then @@ -283,36 +460,14 @@ simplifyPgm (imported_rule_ids, rule_lhs_fvs) else do { -- Dump the result of this iteration - dumpIfSet opt_D_dump_simpl_iterations - ("Simplifier iteration " ++ show iteration_no - ++ " out of " ++ show max_iterations) - (pprSimplCount counts') ; - - if opt_D_dump_simpl_iterations then - endPass ("Simplifier iteration " ++ show iteration_no ++ " result") - opt_D_verbose_core2core - binds' - else - return [] ; - - -- Stop if we've run out of iterations - if iteration_no == max_iterations then - do { -#ifdef DEBUG - if max_iterations > 2 then - hPutStr stderr ("NOTE: Simplifier still going after " ++ - show max_iterations ++ - " iterations; bailing out.\n") - else -#endif - return (); + dumpIfSet_dyn dflags Opt_D_dump_simpl_iterations herald + (pprSimplCount counts') ; - return ("Simplifier baled out", iteration_no, all_counts, binds') - } + endPass dflags herald Opt_D_dump_simpl_iterations binds' ; - -- Else loop - else iteration us2 (iteration_no + 1) all_counts binds' - } } + -- Loop + iteration us2 (iteration_no + 1) all_counts binds' + } } } } where (us1, us2) = splitUniqSupply us \end{code}