X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=ghc%2Fcompiler%2FcoreSyn%2FCoreTidy.lhs;h=bc3dd716f010a93712afd7ec8f9a6a7d4bb7d323;hb=685e04e4af2e2332f2555990122596c7931cb543;hp=e95957443955a0fa98c2959254398024c8d7fa21;hpb=562926d74281d08113893e72edcafaf39b52dafe;p=ghc-hetmet.git diff --git a/ghc/compiler/coreSyn/CoreTidy.lhs b/ghc/compiler/coreSyn/CoreTidy.lhs index e959574..bc3dd71 100644 --- a/ghc/compiler/coreSyn/CoreTidy.lhs +++ b/ghc/compiler/coreSyn/CoreTidy.lhs @@ -5,52 +5,52 @@ \begin{code} module CoreTidy ( - tidyCorePgm, tidyExpr, + tidyCorePgm, tidyExpr, tidyCoreExpr, tidyBndr, tidyBndrs ) where #include "HsVersions.h" -import CmdLineOpts ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas, dopt ) +import CmdLineOpts ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas ) import CoreSyn import CoreUnfold ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile ) import CoreFVs ( ruleSomeFreeVars, exprSomeFreeVars ) +import PprCore ( pprIdCoreRule ) import CoreLint ( showPass, endPass ) import VarEnv import VarSet import Var ( Id, Var ) -import Id ( idType, idInfo, idName, isExportedId, - mkVanillaId, mkId, isLocalId, - setIdStrictness, setIdDemandInfo, +import Id ( idType, idInfo, idName, isExportedId, + idSpecialisation, idUnique, + mkVanillaGlobal, isLocalId, + isImplicitId, mkUserLocal, setIdInfo ) -import IdInfo ( constantIdInfo, - specInfo, setSpecInfo, - cprInfo, setCprInfo, - inlinePragInfo, setInlinePragInfo, isNeverInlinePrag, - strictnessInfo, setStrictnessInfo, isBottomingStrictness, - unfoldingInfo, setUnfoldingInfo, - demandInfo, - occInfo, isLoopBreaker, - workerInfo, setWorkerInfo, WorkerInfo(..) - ) +import IdInfo {- loads of stuff -} +import NewDemand ( isBottomingSig, topSig ) +import BasicTypes ( isNeverActive ) import Name ( getOccName, nameOccName, globaliseName, setNameOcc, - localiseName, mkLocalName, isGlobalName + localiseName, isGlobalName, setNameUnique ) +import NameEnv ( filterNameEnv ) import OccName ( TidyOccEnv, initTidyOccEnv, tidyOccName ) -import Type ( tidyTopType, tidyType, tidyTyVar ) +import Type ( tidyTopType, tidyType, tidyTyVarBndr ) import Module ( Module, moduleName ) -import HscTypes ( PersistentCompilerState( pcs_PRS ), PersistentRenamerState( prsOrig ), - OrigNameEnv( origNames ), OrigNameNameEnv +import HscTypes ( PersistentCompilerState( pcs_PRS ), + PersistentRenamerState( prsOrig ), + NameSupply( nsNames, nsUniqs ), + TypeEnv, extendTypeEnvList, typeEnvIds, + ModDetails(..), TyThing(..) ) -import Unique ( Uniquable(..) ) import FiniteMap ( lookupFM, addToFM ) -import Maybes ( maybeToBool, orElse ) -import ErrUtils ( showPass ) +import Maybes ( orElse ) +import ErrUtils ( showPass, dumpIfSet_core ) import SrcLoc ( noSrcLoc ) import UniqFM ( mapUFM ) -import Outputable +import UniqSupply ( splitUniqSupply, uniqFromSupply ) import List ( partition ) import Util ( mapAccumL ) +import Maybe ( isJust ) +import Outputable \end{code} @@ -79,27 +79,43 @@ exported with their unfoldings, so we produce not an IdSet but an IdEnv Bool - Step 2: Tidy the program ~~~~~~~~~~~~~~~~~~~~~~~~ -Next we traverse the bindings top to bottom. For each top-level +Next we traverse the bindings top to bottom. For each *top-level* binder - - Make all external Ids have Global names and vice versa + 1. Make it into a GlobalId + + 2. Give it a system-wide Unique. + [Even non-exported things need system-wide Uniques because the + byte-code generator builds a single Name->BCO symbol table.] + + We use the NameSupply kept in the PersistentRenamerState as the + source of such system-wide uniques. + + For external Ids, use the original-name cache in the NameSupply + to ensure that the unique assigned is the same as the Id had + in any previous compilation run. + + 3. If it's an external Id, make it have a global Name, otherwise + make it have a local Name. This is used by the code generator to decide whether to make the label externally visible - - Give external ids a "tidy" occurrence name. This means + 4. Give external Ids a "tidy" occurrence name. This means we can print them in interface files without confusing "x" (unique 5) with "x" (unique 10). - - Give external Ids the same Unique as they had before - if the name is in the renamer's name cache - - - Give the Id its final IdInfo; in ptic, - * Its flavour becomes ConstantId, reflecting the fact that - from now on we regard it as a constant, not local, Id + 5. Give it its UTTERLY FINAL IdInfo; in ptic, + * Its IdDetails becomes VanillaGlobal, reflecting the fact that + from now on we regard it as a global, not local, Id + * its unfolding, if it should have one + + * its arity, computed from the number of visible lambdas + + * its CAF info, computed from what is free in its RHS + Finally, substitute these new top-level binders consistently throughout, including in unfoldings. We also tidy binders in @@ -108,27 +124,19 @@ RHSs, so that they print nicely in interfaces. \begin{code} tidyCorePgm :: DynFlags -> Module -> PersistentCompilerState - -> [CoreBind] -> [IdCoreRule] - -> IO (PersistentCompilerState, [CoreBind], [IdCoreRule]) -tidyCorePgm dflags mod pcs binds_in orphans_in + -> CgInfoEnv -- Information from the back end, + -- to be splatted into the IdInfo + -> ModDetails + -> IO (PersistentCompilerState, ModDetails) + +tidyCorePgm dflags mod pcs cg_info_env + (ModDetails { md_types = env_tc, md_insts = insts_tc, + md_binds = binds_in, md_rules = orphans_in }) = do { showPass dflags "Tidy Core" - ; let ext_ids = findExternalSet binds_in orphans_in - - ; let ((orig_env', occ_env, subst_env), binds_out) - = mapAccumL (tidyTopBind mod ext_ids) init_tidy_env binds_in - - ; let orphans_out = tidyIdRules (occ_env,subst_env) orphans_in + ; let ext_ids = findExternalSet binds_in orphans_in + ; let ext_rules = findExternalRules binds_in orphans_in ext_ids - ; let pcs' = pcs { pcs_PRS = prs { prsOrig = orig { origNames = orig_env' }}} - - ; endPass dflags "Tidy Core" (dopt Opt_D_dump_simpl dflags || - dopt Opt_D_verbose_core2core dflags) - binds_out - - ; return (pcs', binds_out, orphans_out) - } - where -- We also make sure to avoid any exported binders. Consider -- f{-u1-} = 1 -- Local decl -- ... @@ -137,31 +145,137 @@ tidyCorePgm dflags mod pcs binds_in orphans_in -- The second exported decl must 'get' the name 'f', so we -- have to put 'f' in the avoids list before we get to the first -- decl. tidyTopId then does a no-op on exported binders. - prs = pcs_PRS pcs - orig = prsOrig prs - orig_env = origNames orig + ; let prs = pcs_PRS pcs + orig_ns = prsOrig prs + + init_tidy_env = (orig_ns, initTidyOccEnv avoids, emptyVarEnv) + avoids = [getOccName name | bndr <- typeEnvIds env_tc, + let name = idName bndr, + isGlobalName name] + -- In computing our "avoids" list, we must include + -- all implicit Ids + -- all things with global names (assigned once and for + -- all by the renamer) + -- since their names are "taken". + -- The type environment is a convenient source of such things. + + ; let ((orig_ns', occ_env, subst_env), tidy_binds) + = mapAccumL (tidyTopBind mod ext_ids cg_info_env) + init_tidy_env binds_in + + ; let tidy_rules = tidyIdRules (occ_env,subst_env) ext_rules + + ; let prs' = prs { prsOrig = orig_ns' } + pcs' = pcs { pcs_PRS = prs' } + + ; let final_ids = [ id + | bind <- tidy_binds + , id <- bindersOf bind + , isGlobalName (idName id)] + + -- Dfuns are local Ids that might have + -- changed their unique during tidying + ; let lookup_dfun_id id = lookupVarEnv subst_env id `orElse` + pprPanic "lookup_dfun_id" (ppr id) + + + ; let tidy_type_env = mkFinalTypeEnv env_tc final_ids + tidy_dfun_ids = map lookup_dfun_id insts_tc + + ; let tidy_details = ModDetails { md_types = tidy_type_env, + md_rules = tidy_rules, + md_insts = tidy_dfun_ids, + md_binds = tidy_binds } + + ; endPass dflags "Tidy Core" Opt_D_dump_simpl tidy_binds + ; dumpIfSet_core dflags Opt_D_dump_simpl + "Tidy Core Rules" + (vcat (map pprIdCoreRule tidy_rules)) + + ; return (pcs', tidy_details) + } - init_tidy_env = (orig_env, initTidyOccEnv avoids, emptyVarEnv) - avoids = [getOccName bndr | bndr <- bindersOfBinds binds_in, - isGlobalName (idName bndr)] +tidyCoreExpr :: CoreExpr -> IO CoreExpr +tidyCoreExpr expr = return (tidyExpr emptyTidyEnv expr) \end{code} %************************************************************************ %* * +\subsection{Write a new interface file} +%* * +%************************************************************************ + +\begin{code} +mkFinalTypeEnv :: TypeEnv -- From typechecker + -> [Id] -- Final Ids + -> TypeEnv + +mkFinalTypeEnv type_env final_ids + = extendTypeEnvList (filterNameEnv keep_it type_env) + (map AnId final_ids) + where + -- The competed type environment is gotten from + -- a) keeping the types and classes + -- b) removing all Ids, + -- c) adding Ids with correct IdInfo, including unfoldings, + -- gotten from the bindings + -- From (c) we keep only those Ids with Global names; + -- the CoreTidy pass makes sure these are all and only + -- the externally-accessible ones + -- This truncates the type environment to include only the + -- exported Ids and things needed from them, which saves space + -- + -- However, we do keep things like constructors, which should not appear + -- in interface files, because they are needed by importing modules when + -- using the compilation manager + + -- We keep implicit Ids, because they won't appear + -- in the bindings from which final_ids are derived! + keep_it (AnId id) = isImplicitId id -- Remove all Ids except implicit ones + keep_it other = True -- Keep all TyCons and Classes +\end{code} + +\begin{code} +findExternalRules :: [CoreBind] + -> [IdCoreRule] -- Orphan rules + -> IdEnv a -- Ids that are exported, so we need their rules + -> [IdCoreRule] + -- The complete rules are gotten by combining + -- a) the orphan rules + -- b) rules embedded in the top-level Ids +findExternalRules binds orphan_rules ext_ids + | opt_OmitInterfacePragmas = [] + | otherwise + = orphan_rules ++ local_rules + where + local_rules = [ (id, rule) + | id <- bindersOfBinds binds, + id `elemVarEnv` ext_ids, + rule <- rulesRules (idSpecialisation id), + not (isBuiltinRule rule) + -- We can't print builtin rules in interface files + -- Since they are built in, an importing module + -- will have access to them anyway + ] +\end{code} + +%************************************************************************ +%* * \subsection{Step 1: finding externals} %* * %************************************************************************ \begin{code} findExternalSet :: [CoreBind] -> [IdCoreRule] - -> IdEnv Bool -- True <=> show unfolding + -> IdEnv Bool -- In domain => external + -- Range = True <=> show unfolding -- Step 1 from the notes above findExternalSet binds orphan_rules = foldr find init_needed binds where orphan_rule_ids :: IdSet - orphan_rule_ids = unionVarSets [ ruleSomeFreeVars isIdAndLocal rule + orphan_rule_ids = unionVarSets [ ruleSomeFreeVars isLocalId rule | (_, rule) <- orphan_rules] init_needed :: IdEnv Bool init_needed = mapUFM (\_ -> False) orphan_rule_ids @@ -189,8 +303,6 @@ findExternalSet binds orphan_rules need_id needed_set id = id `elemVarEnv` needed_set || isExportedId id need_pr needed_set (id,rhs) = need_id needed_set id -isIdAndLocal id = isId id && isLocalId id - addExternal :: (Id,CoreExpr) -> IdEnv Bool -> IdEnv Bool -- The Id is needed; extend the needed set -- with it and its dependents (free vars etc) @@ -208,9 +320,9 @@ addExternal (id,rhs) needed spec_ids idinfo = idInfo id - dont_inline = isNeverInlinePrag (inlinePragInfo idinfo) + dont_inline = isNeverActive (inlinePragInfo idinfo) loop_breaker = isLoopBreaker (occInfo idinfo) - bottoming_fn = isBottomingStrictness (strictnessInfo idinfo) + bottoming_fn = isBottomingSig (newStrictnessInfo idinfo `orElse` topSig) spec_ids = rulesRhsFreeVars (specInfo idinfo) worker_info = workerInfo idinfo @@ -230,7 +342,7 @@ addExternal (id,rhs) needed rhs_is_small && -- Small enough okToUnfoldInHiFile rhs -- No casms etc - unfold_ids | show_unfold = exprSomeFreeVars isIdAndLocal rhs + unfold_ids | show_unfold = exprSomeFreeVars isLocalId rhs | otherwise = emptyVarSet worker_ids = case worker_info of @@ -247,55 +359,68 @@ addExternal (id,rhs) needed \begin{code} -type TopTidyEnv = (OrigNameNameEnv, TidyOccEnv, VarEnv Var) +type TopTidyEnv = (NameSupply, TidyOccEnv, VarEnv Var) -- TopTidyEnv: when tidying we need to know --- * orig_env: Any pre-ordained Names. These may have arisen because the +-- * ns: The NameSupply, containing a unique supply and any pre-ordained Names. +-- These may have arisen because the -- renamer read in an interface file mentioning M.$wf, say, -- and assigned it unique r77. If, on this compilation, we've -- invented an Id whose name is $wf (but with a different unique) -- we want to rename it to have unique r77, so that we can do easy -- comparisons with stuff from the interface file - --- * occ_env: The TidyOccEnv, which tells us which local occurrences are 'used' - +-- +-- * occ_env: The TidyOccEnv, which tells us which local occurrences +-- are 'used' +-- -- * subst_env: A Var->Var mapping that substitutes the new Var for the old \end{code} \begin{code} tidyTopBind :: Module - -> IdEnv Bool -- Domain = Ids that should be exernal + -> IdEnv Bool -- Domain = Ids that should be external -- True <=> their unfolding is external too + -> CgInfoEnv -> TopTidyEnv -> CoreBind -> (TopTidyEnv, CoreBind) -tidyTopBind mod ext_ids env (NonRec bndr rhs) - = (env', NonRec bndr' rhs') +tidyTopBind mod ext_ids cg_info_env top_tidy_env (NonRec bndr rhs) + = ((orig,occ,subst) , NonRec bndr' rhs') where - rhs' = tidyTopRhs env rhs - (env', bndr') = tidyTopBinder mod ext_ids env rhs' env bndr + ((orig,occ,subst), bndr') + = tidyTopBinder mod ext_ids cg_info_env + rec_tidy_env rhs' top_tidy_env bndr + rec_tidy_env = (occ,subst) + rhs' = tidyExpr rec_tidy_env rhs -tidyTopBind mod ext_ids env (Rec prs) +tidyTopBind mod ext_ids cg_info_env top_tidy_env (Rec prs) = (final_env, Rec prs') where - (final_env, prs') = mapAccumL do_one env prs - do_one env (bndr,rhs) = (env', (bndr', rhs')) - where - rhs' = tidyTopRhs final_env rhs - (env', bndr') = tidyTopBinder mod ext_ids final_env - rhs env bndr - -tidyTopRhs :: TopTidyEnv -> CoreExpr -> CoreExpr - -- Just an impedence matcher -tidyTopRhs (_, occ_env, subst_env) rhs = tidyExpr (occ_env, subst_env) rhs - -tidyTopBinder :: Module -> IdEnv Bool - -> TopTidyEnv -> CoreExpr + (final_env@(_,occ,subst), prs') = mapAccumL do_one top_tidy_env prs + rec_tidy_env = (occ,subst) + + do_one top_tidy_env (bndr,rhs) + = ((orig,occ,subst), (bndr',rhs')) + where + ((orig,occ,subst), bndr') + = tidyTopBinder mod ext_ids cg_info_env + rec_tidy_env rhs' top_tidy_env bndr + + rhs' = tidyExpr rec_tidy_env rhs + +tidyTopBinder :: Module -> IdEnv Bool -> CgInfoEnv + -> TidyEnv -> CoreExpr + -- The TidyEnv is used to tidy the IdInfo + -- The expr is the already-tided RHS + -- Both are knot-tied: don't look at them! -> TopTidyEnv -> Id -> (TopTidyEnv, Id) -tidyTopBinder mod ext_ids env_idinfo rhs (orig_env, occ_env, subst_env) id + -- NB: tidyTopBinder doesn't affect the unique supply + +tidyTopBinder mod ext_ids cg_info_env rec_tidy_env rhs + env@(ns2, occ_env2, subst_env2) id -- This function is the heart of Step 2 - -- The second env is the one to use for the IdInfo + -- The rec_tidy_env is the one to use for the IdInfo -- It's necessary because when we are dealing with a recursive -- group, a variable late in the group might be mentioned -- in the IdInfo of one early in the group @@ -304,85 +429,133 @@ tidyTopBinder mod ext_ids env_idinfo rhs (orig_env, occ_env, subst_env) id = ((orig_env', occ_env', subst_env'), id') where - (orig_env', occ_env', name') = tidyTopName mod orig_env occ_env + (orig_env', occ_env', name') = tidyTopName mod ns2 occ_env2 is_external (idName id) - ty' = tidyTopType (idType id) - idinfo' = tidyIdInfo env_idinfo is_external unfold_info id - id' = mkId name' ty' idinfo' - subst_env' = extendVarEnv subst_env id id' + ty' = tidyTopType (idType id) + idinfo = tidyTopIdInfo rec_tidy_env is_external + (idInfo id) unfold_info + (lookupCgInfo cg_info_env name') + + id' = mkVanillaGlobal name' ty' idinfo + + subst_env' = extendVarEnv subst_env2 id id' maybe_external = lookupVarEnv ext_ids id - is_external = maybeToBool maybe_external + is_external = isJust maybe_external -- Expose an unfolding if ext_ids tells us to show_unfold = maybe_external `orElse` False unfold_info | show_unfold = mkTopUnfolding rhs | otherwise = noUnfolding -tidyIdInfo (_, occ_env, subst_env) is_external unfold_info id +-- tidyTopIdInfo creates the final IdInfo for top-level +-- binders. There are two delicate pieces: +-- +-- * Arity. We assume that the simplifier has just run, so +-- that there is a reasonable arity on each binder. +-- After CoreTidy, this arity must not change any more. +-- Indeed, CorePrep must eta expand where necessary to make +-- the manifest arity equal to the claimed arity. +-- +-- * CAF info, which comes from the CoreToStg pass via a knot. +-- The CAF info will not be looked at by the downstream stuff: +-- it *generates* it, and knot-ties it back. It will only be +-- looked at by (a) MkIface when generating an interface file +-- (b) In GHCi, importing modules +-- Nevertheless, we add the info here so that it propagates to all +-- occurrences of the binders in RHSs, and hence to occurrences in +-- unfoldings, which are inside Ids imported by GHCi. Ditto RULES. +-- +-- An alterative would be to do a second pass over the unfoldings +-- of Ids, and rules, right at the top, but that would be a pain. + +tidyTopIdInfo tidy_env is_external idinfo unfold_info cg_info | opt_OmitInterfacePragmas || not is_external - -- No IdInfo if the Id isn't - = constantIdInfo - - | otherwise - = constantIdInfo `setCprInfo` cprInfo core_idinfo - `setStrictnessInfo` strictnessInfo core_idinfo - `setInlinePragInfo` inlinePragInfo core_idinfo - `setUnfoldingInfo` unfold_info - `setWorkerInfo` tidyWorker tidy_env (workerInfo core_idinfo) - `setSpecInfo` tidyRules tidy_env (specInfo core_idinfo) - where - tidy_env = (occ_env, subst_env) - core_idinfo = idInfo id - -tidyTopName mod orig_env occ_env external name - | global && internal = (orig_env, occ_env, localiseName name) - | local && internal = (orig_env, occ_env', setNameOcc name occ') - | global && external = (orig_env, occ_env, name) - | local && external = globalise + -- Only basic info if the Id isn't external, or if we don't have -O + = basic_info + + | otherwise -- Add extra optimisation info + = basic_info + `setInlinePragInfo` inlinePragInfo idinfo + `setUnfoldingInfo` unfold_info + `setWorkerInfo` tidyWorker tidy_env (workerInfo idinfo) + -- NB: we throw away the Rules + -- They have already been extracted by findExternalRules + where + -- baasic_info is attached to every top-level binder + basic_info = vanillaIdInfo + `setCgInfo` cg_info + `setArityInfo` arityInfo idinfo + `setNewStrictnessInfo` newStrictnessInfo idinfo + +-- This is where we set names to local/global based on whether they really are +-- externally visible (see comment at the top of this module). If the name +-- was previously local, we have to give it a unique occurrence name if +-- we intend to globalise it. +tidyTopName mod ns occ_env external name + | global && internal = (ns, occ_env, localiseName name) + + | global && external = (ns, occ_env, name) + -- Global names are assumed to have been allocated by the renamer, + -- so they already have the "right" unique + -- And it's a system-wide unique too + + | local && internal = (ns { nsUniqs = us2 }, occ_env', unique_name) + -- Even local, internal names must get a unique occurrence, because + -- if we do -split-objs we globalise the name later, in the code generator + -- + -- Similarly, we must make sure it has a system-wide Unique, because + -- the byte-code generator builds a system-wide Name->BCO symbol table + + | local && external = case lookupFM ns_names key of + Just orig -> (ns, occ_env', orig) + Nothing -> (ns { nsUniqs = us2, nsNames = ns_names' }, occ_env', global_name) -- If we want to globalise a currently-local name, check -- whether we have already assigned a unique for it. - -- If so, use it; if not, extend the table - globalise = case lookupFM orig_env key of - Just orig -> (orig_env, occ_env', orig) - Nothing -> (addToFM orig_env key global_name, occ_env', global_name) + -- If so, use it; if not, extend the table. + -- This is needed when *re*-compiling a module in GHCi; we want to + -- use the same name for externally-visible things as we did before. - (occ_env', occ') = tidyOccName occ_env (nameOccName name) - key = (moduleName mod, occ') - global_name = globaliseName (setNameOcc name occ') mod + where global = isGlobalName name local = not global internal = not external -tidyIdRules :: TidyEnv -> [IdCoreRule] -> [IdCoreRule] -tidyIdRules env rules - = [ (tidyVarOcc env fn, tidyRule env rule) | (fn,rule) <- rules ] + (occ_env', occ') = tidyOccName occ_env (nameOccName name) + key = (moduleName mod, occ') + ns_names = nsNames ns + ns_uniqs = nsUniqs ns + (us1, us2) = splitUniqSupply ns_uniqs + unique_name = setNameUnique (setNameOcc name occ') (uniqFromSupply us1) + global_name = globaliseName unique_name mod + ns_names' = addToFM ns_names key global_name +------------ Worker -------------- tidyWorker tidy_env (HasWorker work_id wrap_arity) = HasWorker (tidyVarOcc tidy_env work_id) wrap_arity -tidyWorker tidy_env NoWorker +tidyWorker tidy_env other = NoWorker -tidyRules :: TidyEnv -> CoreRules -> CoreRules -tidyRules env (Rules rules fvs) - = Rules (map (tidyRule env) rules) - (foldVarSet tidy_set_elem emptyVarSet fvs) - where - tidy_set_elem var new_set = extendVarSet new_set (tidyVarOcc env var) +------------ Rules -------------- +tidyIdRules :: TidyEnv -> [IdCoreRule] -> [IdCoreRule] +tidyIdRules env [] = [] +tidyIdRules env ((fn,rule) : rules) + = tidyRule env rule =: \ rule -> + tidyIdRules env rules =: \ rules -> + ((tidyVarOcc env fn, rule) : rules) tidyRule :: TidyEnv -> CoreRule -> CoreRule -tidyRule env rule@(BuiltinRule _) = rule -tidyRule env (Rule name vars tpl_args rhs) - = (Rule name vars' (map (tidyExpr env') tpl_args) (tidyExpr env' rhs)) - where - (env', vars') = tidyBndrs env vars +tidyRule env rule@(BuiltinRule _ _) = rule +tidyRule env (Rule name act vars tpl_args rhs) + = tidyBndrs env vars =: \ (env', vars) -> + map (tidyExpr env') tpl_args =: \ tpl_args -> + (Rule name act vars tpl_args (tidyExpr env' rhs)) \end{code} - %************************************************************************ %* * \subsection{Step 2: inner tidying @@ -392,51 +565,42 @@ tidyRule env (Rule name vars tpl_args rhs) \begin{code} tidyBind :: TidyEnv -> CoreBind - -> (TidyEnv, CoreBind) + -> (TidyEnv, CoreBind) + tidyBind env (NonRec bndr rhs) - = let - (env', bndr') = tidyBndr env bndr - rhs' = tidyExpr env' rhs - -- We use env' when tidying the RHS even though it's not - -- strictly necessary; it makes the tidied code pretty - -- hard to read if we don't! - in - (env', NonRec bndr' rhs') + = tidyLetBndr env (bndr,rhs) =: \ (env', bndr') -> + (env', NonRec bndr' (tidyExpr env' rhs)) tidyBind env (Rec prs) - = (final_env, Rec prs') - where - (final_env, prs') = mapAccumL do_one env prs - do_one env (bndr,rhs) = (env', (bndr', rhs')) - where - (env', bndr') = tidyBndr env bndr - rhs' = tidyExpr final_env rhs + = mapAccumL tidyLetBndr env prs =: \ (env', bndrs') -> + map (tidyExpr env') (map snd prs) =: \ rhss' -> + (env', Rec (zip bndrs' rhss')) -tidyExpr env (Type ty) = Type (tidyType env ty) -tidyExpr env (Lit lit) = Lit lit -tidyExpr env (App f a) = App (tidyExpr env f) (tidyExpr env a) -tidyExpr env (Note n e) = Note (tidyNote env n) (tidyExpr env e) -tidyExpr env (Let b e) = Let b' (tidyExpr env' e) - where - (env', b') = tidyBind env b +tidyExpr env (Var v) = Var (tidyVarOcc env v) +tidyExpr env (Type ty) = Type (tidyType env ty) +tidyExpr env (Lit lit) = Lit lit +tidyExpr env (App f a) = App (tidyExpr env f) (tidyExpr env a) +tidyExpr env (Note n e) = Note (tidyNote env n) (tidyExpr env e) -tidyExpr env (Case e b alts) = Case (tidyExpr env e) b' (map (tidyAlt env') alts) - where - (env', b') = tidyBndr env b +tidyExpr env (Let b e) + = tidyBind env b =: \ (env', b') -> + Let b' (tidyExpr env' e) -tidyExpr env (Var v) = Var (tidyVarOcc env v) +tidyExpr env (Case e b alts) + = tidyBndr env b =: \ (env', b) -> + Case (tidyExpr env e) b (map (tidyAlt env') alts) -tidyExpr env (Lam b e) = Lam b' (tidyExpr env' e) - where - (env', b') = tidyBndr env b +tidyExpr env (Lam b e) + = tidyBndr env b =: \ (env', b) -> + Lam b (tidyExpr env' e) -tidyAlt env (con, vs, rhs) = (con, vs', tidyExpr env' rhs) - where - (env', vs') = tidyBndrs env vs -tidyNote env (Coerce t1 t2) = Coerce (tidyType env t1) (tidyType env t2) +tidyAlt env (con, vs, rhs) + = tidyBndrs env vs =: \ (env', vs) -> + (con, vs, tidyExpr env' rhs) +tidyNote env (Coerce t1 t2) = Coerce (tidyType env t1) (tidyType env t2) tidyNote env note = note \end{code} @@ -452,35 +616,62 @@ tidyVarOcc (_, var_env) v = case lookupVarEnv var_env v of Just v' -> v' Nothing -> v +-- tidyBndr is used for lambda and case binders tidyBndr :: TidyEnv -> Var -> (TidyEnv, Var) -tidyBndr env var | isTyVar var = tidyTyVar env var - | otherwise = tidyId env var +tidyBndr env var + | isTyVar var = tidyTyVarBndr env var + | otherwise = tidyIdBndr env var tidyBndrs :: TidyEnv -> [Var] -> (TidyEnv, [Var]) tidyBndrs env vars = mapAccumL tidyBndr env vars -tidyId :: TidyEnv -> Id -> (TidyEnv, Id) -tidyId env@(tidy_env, var_env) id +tidyLetBndr :: TidyEnv -> (Id, CoreExpr) -> (TidyEnv, Var) +-- Used for local (non-top-level) let(rec)s +tidyLetBndr env (id,rhs) + = ((tidy_env,new_var_env), final_id) + where + ((tidy_env,var_env), new_id) = tidyIdBndr env id + + -- We need to keep around any interesting strictness and demand info + -- because later on we may need to use it when converting to A-normal form. + -- eg. + -- f (g x), where f is strict in its argument, will be converted + -- into case (g x) of z -> f z by CorePrep, but only if f still + -- has its strictness info. + -- + -- Similarly for the demand info - on a let binder, this tells + -- CorePrep to turn the let into a case. + -- + -- Similarly arity info for eta expansion in CorePrep + final_id = new_id `setIdInfo` new_info + idinfo = idInfo id + new_info = vanillaIdInfo + `setArityInfo` arityInfo idinfo + `setNewStrictnessInfo` newStrictnessInfo idinfo + `setNewDemandInfo` newDemandInfo idinfo + + -- Override the env we get back from tidyId with the new IdInfo + -- so it gets propagated to the usage sites. + new_var_env = extendVarEnv var_env id final_id + +tidyIdBndr :: TidyEnv -> Id -> (TidyEnv, Id) +tidyIdBndr env@(tidy_env, var_env) id = -- Non-top-level variables let -- Give the Id a fresh print-name, *and* rename its type - -- The SrcLoc isn't important now, though we could extract it from the Id - name' = mkLocalName (getUnique id) occ' noSrcLoc + -- The SrcLoc isn't important now, + -- though we could extract it from the Id + -- + -- All nested Ids now have the same IdInfo, namely none, + -- which should save some space. (tidy_env', occ') = tidyOccName tidy_env (getOccName id) ty' = tidyType env (idType id) - idinfo = idInfo id - id' = mkVanillaId name' ty' - `setIdStrictness` strictnessInfo idinfo - `setIdDemandInfo` demandInfo idinfo - -- 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. - -- - -- The exception is strictness and demand info, which - -- is used to decide whether to use let or case for - -- function arguments and let bindings - + id' = mkUserLocal occ' (idUnique id) ty' noSrcLoc var_env' = extendVarEnv var_env id id' in - ((tidy_env', var_env'), id') + ((tidy_env', var_env'), id') +\end{code} + +\begin{code} +m =: k = m `seq` k m \end{code}