\begin{code}
module CoreTidy (
- tidyCorePgm, tidyExpr,
+ tidyCorePgm, tidyExpr, tidyCoreExpr,
tidyBndr, tidyBndrs
) where
import CmdLineOpts ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas )
import CoreSyn
import CoreUnfold ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile )
-import CoreUtils ( exprArity )
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,
- idCafInfo, mkId, isLocalId, isImplicitId,
- idFlavour, modifyIdInfo, idArity
+import Id ( idType, idInfo, idName, isExportedId,
+ idSpecialisation, idUnique, isDataConWrapId,
+ mkVanillaGlobal, mkGlobalId, isLocalId,
+ hasNoBinding, mkUserLocal, isGlobalId, globalIdDetails,
+ idNewDemandInfo, setIdNewDemandInfo,
+ idNewStrictness_maybe, setIdNewStrictness
)
import IdInfo {- loads of stuff -}
+import NewDemand ( isBottomingSig, topSig, isStrictDmd )
+import BasicTypes ( isNeverActive )
import Name ( getOccName, nameOccName, globaliseName, setNameOcc,
- localiseName, mkLocalName, isGlobalName, isDllName
+ 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 PrimOp ( PrimOp(..), setCCallUnique )
import HscTypes ( PersistentCompilerState( pcs_PRS ),
PersistentRenamerState( prsOrig ),
- NameSupply( nsNames ), OrigNameCache
+ NameSupply( nsNames, nsUniqs ),
+ TypeEnv, extendTypeEnvList,
+ ModDetails(..), TyThing(..)
)
-import UniqSupply
-import DataCon ( dataConName )
-import Literal ( isLitLitLit )
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 FastTypes
+import UniqSupply ( splitUniqSupply, uniqFromSupply )
import List ( partition )
import Util ( mapAccumL )
+import Maybe ( isJust, fromJust, isNothing )
+import Outputable
\end{code}
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
-
- - Clone all local Ids. This means that Tidy Core has the property
- that all Ids are unique, rather than the weaker guarantee of
- no clashes which the simplifier provides.
-
- - Give each dynamic CCall occurrence a fresh unique; this is
- rather like the cloning step above.
-
- - Give the Id its UTTERLY 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
\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
-
- ; us <- mkSplitUniqSupply 't' -- for "tidy"
-
- ; let ((us1, orig_env', occ_env, subst_env), binds_out)
- = mapAccumL (tidyTopBind mod ext_ids)
- (init_tidy_env us) binds_in
+ ; let ext_ids = findExternalSet binds_in orphans_in
+ ; let ext_rules = findExternalRules binds_in orphans_in ext_ids
- ; let (orphans_out, _)
- = initUs us1 (tidyIdRules (occ_env,subst_env) orphans_in)
-
- ; let prs' = prs { prsOrig = orig { nsNames = orig_env' } }
- pcs' = pcs { pcs_PRS = prs' }
-
- ; endPass dflags "Tidy Core" Opt_D_dump_simpl binds_out
-
- ; return (pcs', binds_out, orphans_out)
- }
- where
-- We also make sure to avoid any exported binders. Consider
-- f{-u1-} = 1 -- Local decl
-- ...
-- 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 = nsNames orig
+ ; let prs = pcs_PRS pcs
+ orig_ns = prsOrig prs
+
+ init_tidy_env = (orig_ns, initTidyOccEnv avoids, emptyVarEnv)
+ avoids = [getOccName bndr | bndr <- bindersOfBinds binds_in,
+ isGlobalName (idName bndr)]
+
+ ; 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)
+ }
+
+tidyCoreExpr :: CoreExpr -> IO CoreExpr
+tidyCoreExpr expr = return (tidyExpr emptyTidyEnv expr)
+\end{code}
- init_tidy_env us = (us, orig_env, initTidyOccEnv avoids, emptyVarEnv)
- avoids = [getOccName bndr | bndr <- bindersOfBinds binds_in,
- isGlobalName (idName bndr)]
+
+%************************************************************************
+%* *
+\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 "hasNoBinding" Ids, notably constructor workers,
+ -- because they won't appear in the bindings from which final_ids are derived!
+ keep_it (AnId id) = hasNoBinding id -- Remove all Ids except constructor workers
+ 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}
%************************************************************************
%* *
\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
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)
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
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
\begin{code}
-type TopTidyEnv = (UniqSupply, OrigNameCache, 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)
-- are 'used'
--
-- * subst_env: A Var->Var mapping that substitutes the new Var for the old
---
--- * uniqsuppy: so we can clone any Ids with non-preordained names.
---
\end{code}
tidyTopBind :: Module
-> 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)
- = ((us2,orig,occ,subst) , NonRec bndr' rhs')
+tidyTopBind mod ext_ids cg_info_env top_tidy_env (NonRec bndr rhs)
+ = ((orig,occ,subst) , NonRec bndr' rhs')
where
- ((us1,orig,occ,subst), bndr')
- = tidyTopBinder mod ext_ids tidy_env rhs' caf_info env bndr
- tidy_env = (occ,subst)
- caf_info = hasCafRefs (const True) rhs'
- (rhs',us2) = initUs us1 (tidyExpr tidy_env rhs)
+ ((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@(_,_,occ,subst), prs') = mapAccumL do_one env prs
- final_tidy_env = (occ,subst)
+ (final_env@(_,occ,subst), prs') = mapAccumL do_one top_tidy_env prs
+ rec_tidy_env = (occ,subst)
- do_one env (bndr,rhs)
- = ((us',orig,occ,subst), (bndr',rhs'))
+ do_one top_tidy_env (bndr,rhs)
+ = ((orig,occ,subst), (bndr',rhs'))
where
- ((us,orig,occ,subst), bndr')
- = tidyTopBinder mod ext_ids final_tidy_env rhs' caf_info env bndr
- (rhs', us') = initUs us (tidyExpr final_tidy_env rhs)
-
- -- the CafInfo for a recursive group says whether *any* rhs in
- -- the group may refer indirectly to a CAF (because then, they all do).
- (bndrs, rhss) = unzip prs'
- caf_info = hasCafRefss pred rhss
- pred v = v `notElem` bndrs
+ ((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
- -> TidyEnv -> CoreExpr -> CafInfo
+ -> 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)
+ -- NB: tidyTopBinder doesn't affect the unique supply
+
+tidyTopBinder mod ext_ids cg_info_env tidy_env rhs
+ env@(ns2, occ_env2, subst_env2) id
+
+ | isDataConWrapId id -- Don't tidy constructor wrappers
+ = (env, id) -- The Id is stored in the TyCon, so it would be bad
+ -- if anything changed
+
+-- HACK ALERT: we *do* tidy record selectors. Reason: they mention error
+-- messages, which may be floated out:
+-- x_field pt = case pt of
+-- Rect x y -> y
+-- Pol _ _ -> error "buggle wuggle"
+-- The error message will be floated out so we'll get
+-- lvl5 = error "buggle wuggle"
+-- x_field pt = case pt of
+-- Rect x y -> y
+-- Pol _ _ -> lvl5
+--
+-- When this happens, it's vital that the Id exposed to importing modules
+-- (by ghci) mentions lvl5 in its unfolding, not the un-tidied version.
+--
+-- What about the Id in the TyCon? It probably shouldn't be in the TyCon at
+-- all, but in any case it will have the error message inline so it won't matter.
-tidyTopBinder mod ext_ids tidy_env rhs caf_info
- env@(us, orig_env2, occ_env2, subst_env2) id
-
- | isImplicitId id -- Don't mess with constructors,
- = (env, id) -- record selectors, and the like
| otherwise
-- This function is the heart of Step 2
-- The rhs is already tidied
- = ((us_r, orig_env', occ_env', subst_env'), id')
+ = ((orig_env', occ_env', subst_env'), id')
where
- (us_l, us_r) = splitUniqSupply us
-
- (orig_env', occ_env', name') = tidyTopName mod orig_env2 occ_env2
+ (orig_env', occ_env', name') = tidyTopName mod ns2 occ_env2
is_external
(idName id)
- ty' = tidyTopType (idType id)
- idinfo' = tidyIdInfo us_l tidy_env
- is_external unfold_info arity_info caf_info id
+ ty' = tidyTopType (idType id)
+ cg_info = lookupCgInfo cg_info_env name'
+ idinfo' = tidyIdInfo tidy_env is_external unfold_info cg_info id
+
+ id' | isGlobalId id = mkGlobalId (globalIdDetails id) name' ty' idinfo'
+ | otherwise = mkVanillaGlobal name' ty' idinfo'
+ -- The test ensures that record selectors (which must be tidied; see above)
+ -- retain their details. If it's forgotten, importing modules get confused.
- id' = mkId 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
- arity_info = exprArity rhs
-
-tidyIdInfo us tidy_env is_external unfold_info arity_info caf_info id
+tidyIdInfo tidy_env is_external unfold_info cg_info id
| opt_OmitInterfacePragmas || not is_external
-- No IdInfo if the Id isn't external, or if we don't have -O
- = mkIdInfo new_flavour caf_info
- `setStrictnessInfo` strictnessInfo core_idinfo
- `setArityInfo` ArityExactly arity_info
- -- Keep strictness, arity and CAF info; it's used by the code generator
+ = vanillaIdInfo
+ `setCgInfo` cg_info
+ `setNewStrictnessInfo` newStrictnessInfo core_idinfo
+ -- Keep strictness; it's used by CorePrep
| otherwise
- = let (rules', _) = initUs us (tidyRules tidy_env (specInfo core_idinfo))
- in
- mkIdInfo new_flavour caf_info
- `setCprInfo` cprInfo core_idinfo
- `setStrictnessInfo` strictnessInfo core_idinfo
- `setInlinePragInfo` inlinePragInfo core_idinfo
- `setUnfoldingInfo` unfold_info
- `setWorkerInfo` tidyWorker tidy_env arity_info (workerInfo core_idinfo)
- `setSpecInfo` rules'
- `setArityInfo` ArityExactly arity_info
- -- this is the final IdInfo, it must agree with the
- -- code finally generated (i.e. NO more transformations
- -- after this!).
+ = vanillaIdInfo
+ `setCgInfo` cg_info
+ `setNewStrictnessInfo` newStrictnessInfo core_idinfo
+ `setInlinePragInfo` inlinePragInfo core_idinfo
+ `setUnfoldingInfo` unfold_info
+ `setWorkerInfo` tidyWorker tidy_env (workerInfo core_idinfo)
+ -- NB: we throw away the Rules
+ -- They have already been extracted by findExternalRules
where
core_idinfo = idInfo id
- -- A DFunId must stay a DFunId, so that we can gather the
- -- DFunIds up later. Other local things become ConstantIds.
- new_flavour = case flavourInfo core_idinfo of
- VanillaId -> ConstantId
- ExportedId -> ConstantId
- ConstantId -> ConstantId -- e.g. Default methods
- DictFunId -> DictFunId
- flavour -> pprTrace "tidyIdInfo" (ppr id <+> ppFlavourInfo flavour)
- flavour
-
-- 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 orig_env occ_env external name
- | global && internal = (orig_env, occ_env, localiseName name)
-
- | local && internal = (orig_env, occ_env', setNameOcc name occ')
- -- Even local, internal names must get a unique occurrence, because
- -- if we do -split-objs we globalise the name later, n the code generator
+tidyTopName mod ns occ_env external name
+ | global && internal = (ns, occ_env, localiseName name)
- | global && external = (orig_env, occ_env, 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 && external = case lookupFM orig_env key of
- Just orig -> (orig_env, occ_env', orig)
- Nothing -> (addToFM orig_env key global_name, occ_env', global_name)
+ | 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
where
- (occ_env', occ') = tidyOccName occ_env (nameOccName name)
- key = (moduleName mod, occ')
- global_name = globaliseName (setNameOcc name occ') mod
global = isGlobalName name
local = not global
internal = not external
+ (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 --------------
--- We only treat a function as having a worker if
--- the exported arity (which is now the number of visible lambdas)
--- is the same as the arity at the moment of the w/w split
--- If so, we can safely omit the unfolding inside the wrapper, and
--- instead re-generate it from the type/arity/strictness info
--- But if the arity has changed, we just take the simple path and
--- put the unfolding into the interface file, forgetting the fact
--- that it's a wrapper.
---
--- How can this happen? Sometimes we get
--- f = coerce t (\x y -> $wf x y)
--- at the moment of w/w split; but the eta reducer turns it into
--- f = coerce t $wf
--- which is perfectly fine except that the exposed arity so far as
--- the code generator is concerned (zero) differs from the arity
--- when we did the split (2).
---
--- All this arises because we use 'arity' to mean "exactly how many
--- top level lambdas are there" in interface files; but during the
--- compilation of this module it means "how many things can I apply
--- this to".
-tidyWorker tidy_env real_arity (HasWorker work_id wrap_arity)
- | real_arity == wrap_arity
+tidyWorker tidy_env (HasWorker work_id wrap_arity)
= HasWorker (tidyVarOcc tidy_env work_id) wrap_arity
-tidyWorker tidy_env real_arity other
+tidyWorker tidy_env other
= NoWorker
------------ Rules --------------
-tidyIdRules :: TidyEnv -> [IdCoreRule] -> UniqSM [IdCoreRule]
-tidyIdRules env [] = returnUs []
+tidyIdRules :: TidyEnv -> [IdCoreRule] -> [IdCoreRule]
+tidyIdRules env [] = []
tidyIdRules env ((fn,rule) : rules)
- = tidyRule env rule `thenUs` \ rule ->
- tidyIdRules env rules `thenUs` \ rules ->
- returnUs ((tidyVarOcc env fn, rule) : rules)
-
-tidyRules :: TidyEnv -> CoreRules -> UniqSM CoreRules
-tidyRules env (Rules rules fvs)
- = mapUs (tidyRule env) rules `thenUs` \ rules ->
- returnUs (Rules rules (foldVarSet tidy_set_elem emptyVarSet fvs))
- where
- tidy_set_elem var new_set = extendVarSet new_set (tidyVarOcc env var)
-
-tidyRule :: TidyEnv -> CoreRule -> UniqSM CoreRule
-tidyRule env rule@(BuiltinRule _) = returnUs rule
-tidyRule env (Rule name vars tpl_args rhs)
- = tidyBndrs env vars `thenUs` \ (env', vars) ->
- mapUs (tidyExpr env') tpl_args `thenUs` \ tpl_args ->
- tidyExpr env' rhs `thenUs` \ rhs ->
- returnUs (Rule name vars tpl_args rhs)
+ = 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 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}
%************************************************************************
\begin{code}
tidyBind :: TidyEnv
-> CoreBind
- -> UniqSM (TidyEnv, CoreBind)
+ -> (TidyEnv, CoreBind)
+
tidyBind env (NonRec bndr rhs)
- = tidyBndrWithRhs env (bndr,rhs) `thenUs` \ (env', bndr') ->
- tidyExpr env' rhs `thenUs` \ rhs' ->
- returnUs (env', NonRec bndr' rhs')
+ = tidyLetBndr env (bndr,rhs) =: \ (env', bndr') ->
+ (env', NonRec bndr' (tidyExpr env' rhs))
tidyBind env (Rec prs)
- = mapAccumLUs tidyBndrWithRhs env prs `thenUs` \ (env', bndrs') ->
- mapUs (tidyExpr env') (map snd prs) `thenUs` \ rhss' ->
- returnUs (env', Rec (zip bndrs' rhss'))
-
-tidyExpr env (Var v)
- = fiddleCCall v `thenUs` \ v ->
- returnUs (Var (tidyVarOcc env v))
+ = mapAccumL tidyLetBndr env prs =: \ (env', bndrs') ->
+ map (tidyExpr env') (map snd prs) =: \ rhss' ->
+ (env', Rec (zip bndrs' rhss'))
-tidyExpr env (Type ty) = returnUs (Type (tidyType env ty))
-tidyExpr env (Lit lit) = returnUs (Lit lit)
-tidyExpr env (App f a)
- = tidyExpr env f `thenUs` \ f ->
- tidyExpr env a `thenUs` \ a ->
- returnUs (App f a)
-
-tidyExpr env (Note n e)
- = tidyExpr env e `thenUs` \ e ->
- returnUs (Note (tidyNote env n) e)
+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 (Let b e)
- = tidyBind env b `thenUs` \ (env', b') ->
- tidyExpr env' e `thenUs` \ e ->
- returnUs (Let b' e)
+ = tidyBind env b =: \ (env', b') ->
+ Let b' (tidyExpr env' e)
tidyExpr env (Case e b alts)
- = tidyExpr env e `thenUs` \ e ->
- tidyBndr env b `thenUs` \ (env', b) ->
- mapUs (tidyAlt env') alts `thenUs` \ alts ->
- returnUs (Case e b alts)
+ = tidyBndr env b =: \ (env', b) ->
+ Case (tidyExpr env e) b (map (tidyAlt env') alts)
tidyExpr env (Lam b e)
- = tidyBndr env b `thenUs` \ (env', b) ->
- tidyExpr env' e `thenUs` \ e ->
- returnUs (Lam b e)
+ = tidyBndr env b =: \ (env', b) ->
+ Lam b (tidyExpr env' e)
tidyAlt env (con, vs, rhs)
- = tidyBndrs env vs `thenUs` \ (env', vs) ->
- tidyExpr env' rhs `thenUs` \ rhs ->
- returnUs (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
Nothing -> v
-- tidyBndr is used for lambda and case binders
-tidyBndr :: TidyEnv -> Var -> UniqSM (TidyEnv, Var)
+tidyBndr :: TidyEnv -> Var -> (TidyEnv, Var)
tidyBndr env var
- | isTyVar var = returnUs (tidyTyVar env var)
- | otherwise = tidyId env var vanillaIdInfo
-
-tidyBndrs :: TidyEnv -> [Var] -> UniqSM (TidyEnv, [Var])
-tidyBndrs env vars = mapAccumLUs tidyBndr env vars
-
--- tidyBndrWithRhs is used for let binders
-tidyBndrWithRhs :: TidyEnv -> (Var, CoreExpr) -> UniqSM (TidyEnv, Var)
-tidyBndrWithRhs env (id,rhs)
- = tidyId env id idinfo
- where
- idinfo = vanillaIdInfo `setArityInfo` ArityExactly (exprArity rhs)
- -- 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.
-
-tidyId :: TidyEnv -> Id -> IdInfo -> UniqSM (TidyEnv, Id)
-tidyId env@(tidy_env, var_env) id idinfo
+ | isTyVar var = tidyTyVarBndr env var
+ | otherwise = tidyIdBndr env var
+
+tidyBndrs :: TidyEnv -> [Var] -> (TidyEnv, [Var])
+tidyBndrs env vars = mapAccumL tidyBndr env vars
+
+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.
+ final_id
+ | totally_boring_info = new_id
+ | otherwise = new_id `setIdNewDemandInfo` dmd_info
+ `setIdNewStrictness` fromJust maybe_new_strictness
+
+ -- 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
+
+ dmd_info = idNewDemandInfo id
+ maybe_new_strictness = idNewStrictness_maybe id
+ totally_boring_info = isNothing maybe_new_strictness && not (isStrictDmd dmd_info)
+
+tidyIdBndr :: TidyEnv -> Id -> (TidyEnv, Id)
+tidyIdBndr env@(tidy_env, var_env) id
= -- Non-top-level variables
- getUniqueUs `thenUs` \ uniq ->
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 uniq occ' noSrcLoc
+ --
+ -- All local Ids now have the same IdInfo, which should save some
+ -- space.
(tidy_env', occ') = tidyOccName tidy_env (getOccName id)
- ty' = tidyType (tidy_env,var_env) (idType id)
- id' = mkId name' ty' idinfo
+ ty' = tidyType env (idType id)
+ id' = mkUserLocal occ' (idUnique id) ty' noSrcLoc
var_env' = extendVarEnv var_env id id'
in
- returnUs ((tidy_env', var_env'), id')
-
-
-fiddleCCall id
- = case idFlavour id of
- PrimOpId (CCallOp ccall) ->
- -- Make a guaranteed unique name for a dynamic ccall.
- getUniqueUs `thenUs` \ uniq ->
- returnUs (modifyIdInfo (`setFlavourInfo`
- PrimOpId (CCallOp (setCCallUnique ccall uniq))) id)
- other_flavour ->
- returnUs id
+ ((tidy_env', var_env'), id')
\end{code}
-%************************************************************************
-%* *
-\subsection{Figuring out CafInfo for an expression}
-%* *
-%************************************************************************
-
\begin{code}
-hasCafRefs :: (Id -> Bool) -> CoreExpr -> CafInfo
-hasCafRefss :: (Id -> Bool) -> [CoreExpr] -> CafInfo
- -- predicate returns True for a given Id if we look at this Id when
- -- calculating the result. Used to *avoid* looking at the CafInfo
- -- field for an Id that is part of the current recursive group.
-
-hasCafRefs p expr = if isCAF expr || isFastTrue (cafRefs p expr)
- then MayHaveCafRefs
- else NoCafRefs
-
- -- used for recursive groups. The whole group is set to
- -- "MayHaveCafRefs" if at least one of the group is a CAF or
- -- refers to any CAFs.
-hasCafRefss p exprs = if any isCAF exprs || isFastTrue (cafRefss p exprs)
- then MayHaveCafRefs
- else NoCafRefs
-
-cafRefs p (Var id)
- | p id
- = case idCafInfo id of
- NoCafRefs -> fastBool False
- MayHaveCafRefs -> fastBool True
- | otherwise
- = fastBool False
-
-cafRefs p (Lit l) = fastBool False
-cafRefs p (App f a) = cafRefs p f `fastOr` cafRefs p a
-cafRefs p (Lam x e) = cafRefs p e
-cafRefs p (Let b e) = cafRefss p (rhssOfBind b) `fastOr` cafRefs p e
-cafRefs p (Case e bndr alts) = cafRefs p e `fastOr` cafRefss p (rhssOfAlts alts)
-cafRefs p (Note n e) = cafRefs p e
-cafRefs p (Type t) = fastBool False
-
-cafRefss p [] = fastBool False
-cafRefss p (e:es) = cafRefs p e `fastOr` cafRefss p es
-
--- Decide whether a closure looks like a CAF or not. In an effort to
--- keep the number of CAFs (and hence the size of the SRTs) down, we
--- would also like to look at the expression and decide whether it
--- requires a small bounded amount of heap, so we can ignore it as a
--- CAF. In these cases however, we would need to use an additional
--- CAF list to keep track of non-collectable CAFs.
-
--- We mark real CAFs as `MayHaveCafRefs' because this information is
--- used to decide whether a particular closure needs to be referenced
--- in an SRT or not.
-
-isCAF :: CoreExpr -> Bool
-isCAF e = not (rhsIsNonUpd e)
- {- ToDo: check type for onceness, i.e. non-updatable thunks? -}
-
-rhsIsNonUpd :: CoreExpr -> Bool -- True => Value-lambda, constructor, PAP
-rhsIsNonUpd (Lam b e) = isId b || rhsIsNonUpd e
-rhsIsNonUpd (Note (SCC _) e) = False
-rhsIsNonUpd (Note _ e) = rhsIsNonUpd e
-rhsIsNonUpd other_expr
- = go other_expr 0 []
- where
- go (Var f) n_args args = idAppIsNonUpd f n_args args
-
- go (App f a) n_args args
- | isTypeArg a = go f n_args args
- | otherwise = go f (n_args + 1) (a:args)
-
- go (Note (SCC _) f) n_args args = False
- go (Note _ f) n_args args = go f n_args args
-
- go other n_args args = False
-
-idAppIsNonUpd :: Id -> Int -> [CoreExpr] -> Bool
-idAppIsNonUpd id n_val_args args
- = case idFlavour id of
- DataConId con | not (isDynConApp con args) -> True
- other -> n_val_args < idArity id
-
-isDynConApp con args = isDllName (dataConName con) || any isDynArg args
-
- -- Does this argument refer to something in a different DLL,
- -- or is a LitLit? Constructor arguments which are in another
- -- DLL or are LitLits aren't compiled into static constructors
- -- (see CoreToStg), so we have to take that into account here.
-isDynArg :: CoreExpr -> Bool
-isDynArg (Var v) = isDllName (idName v)
-isDynArg (Note _ e) = isDynArg e
-isDynArg (Lit lit) = isLitLitLit lit
-isDynArg (App e _) = isDynArg e -- must be a type app
-isDynArg (Lam _ e) = isDynArg e -- must be a type lam
-
--- We consider partial applications to be non-updatable. NOTE: this
--- must match how CoreToStg marks the closure.
+m =: k = m `seq` k m
\end{code}
projects / ghc-hetmet.git / blobdiff