%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
+% (c) The AQUA Project, Glasgow University, 1996-1998
%
-\section{Tidying up Core}
\begin{code}
module CoreTidy (
- tidyCorePgm, tidyExpr,
- tidyBndr, tidyBndrs
+ tidyExpr, tidyVarOcc, tidyRule, tidyRules
) where
#include "HsVersions.h"
-import CmdLineOpts ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas )
import CoreSyn
-import CoreUnfold ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile )
-import CoreUtils ( exprArity, exprIsBottom )
-import CoreFVs ( ruleSomeFreeVars, exprSomeFreeVars )
-import CoreLint ( showPass, endPass )
+import CoreUtils ( exprArity )
+import Unify ( coreRefineTys )
+import DataCon ( DataCon, isVanillaDataCon )
+import Id ( Id, mkUserLocal, idInfo, setIdInfo, idUnique,
+ idType, setIdType )
+import IdInfo ( setArityInfo, vanillaIdInfo,
+ newStrictnessInfo, setAllStrictnessInfo,
+ newDemandInfo, setNewDemandInfo )
+import Type ( Type, tidyType, tidyTyVarBndr, substTy, mkOpenTvSubst )
+import Var ( Var, TyVar, varName )
import VarEnv
-import VarSet
-import Var ( Id, Var )
-import Id ( idType, idInfo, idName, isExportedId,
- idCafInfo, mkId, isLocalId, isImplicitId,
- idFlavour, modifyIdInfo
- )
-import IdInfo {- loads of stuff -}
-import Name ( getOccName, nameOccName, globaliseName, setNameOcc,
- localiseName, mkLocalName, isGlobalName
- )
-import OccName ( TidyOccEnv, initTidyOccEnv, tidyOccName )
-import Type ( tidyTopType, tidyType, tidyTyVar )
-import Module ( Module, moduleName )
-import PrimOp ( PrimOp(..), setCCallUnique )
-import HscTypes ( PersistentCompilerState( pcs_PRS ),
- PersistentRenamerState( prsOrig ),
- OrigNameEnv( origNames ), OrigNameNameEnv
- )
-import UniqSupply
-import FiniteMap ( lookupFM, addToFM )
-import Maybes ( maybeToBool, orElse )
-import ErrUtils ( showPass )
+import UniqFM ( lookupUFM )
+import Name ( Name, getOccName )
+import OccName ( tidyOccName )
import SrcLoc ( noSrcLoc )
-import UniqFM ( mapUFM )
+import Maybes ( orElse )
import Outputable
-import FastTypes
-import List ( partition )
import Util ( mapAccumL )
\end{code}
-
-%************************************************************************
-%* *
-\subsection{What goes on}
-%* *
-%************************************************************************
-
-[SLPJ: 19 Nov 00]
-
-The plan is this.
-
-Step 1: Figure out external Ids
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-First we figure out which Ids are "external" Ids. An
-"external" Id is one that is visible from outside the compilation
-unit. These are
- a) the user exported ones
- b) ones mentioned in the unfoldings, workers,
- or rules of externally-visible ones
-This exercise takes a sweep of the bindings bottom to top. Actually,
-in Step 2 we're also going to need to know which Ids should be
-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
-binder
-
- - Make all external Ids have Global names and vice versa
- 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
- 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 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
- * its unfolding, if it should have one
-
-Finally, substitute these new top-level binders consistently
-throughout, including in unfoldings. We also tidy binders in
-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
- = 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 (orphans_out, _)
- = initUs us1 (tidyIdRules (occ_env,subst_env) orphans_in)
-
- ; let prs' = prs { prsOrig = orig { origNames = 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
- -- ...
- -- f{-u2-} = 2 -- Exported 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 = origNames orig
-
- init_tidy_env us = (us, orig_env, initTidyOccEnv avoids, emptyVarEnv)
- avoids = [getOccName bndr | bndr <- bindersOfBinds binds_in,
- isGlobalName (idName bndr)]
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{Step 1: finding externals}
-%* *
-%************************************************************************
-
-\begin{code}
-findExternalSet :: [CoreBind] -> [IdCoreRule]
- -> IdEnv Bool -- 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
- | (_, rule) <- orphan_rules]
- init_needed :: IdEnv Bool
- init_needed = mapUFM (\_ -> False) orphan_rule_ids
- -- The mapUFM is a bit cheesy. It is a cheap way
- -- to turn the set of orphan_rule_ids, which we use to initialise
- -- the sweep, into a mapping saying 'don't expose unfolding'
- -- (When we come to the binding site we may change our mind, of course.)
-
- find (NonRec id rhs) needed
- | need_id needed id = addExternal (id,rhs) needed
- | otherwise = needed
- find (Rec prs) needed = find_prs prs needed
-
- -- For a recursive group we have to look for a fixed point
- find_prs prs needed
- | null needed_prs = needed
- | otherwise = find_prs other_prs new_needed
- where
- (needed_prs, other_prs) = partition (need_pr needed) prs
- new_needed = foldr addExternal needed needed_prs
-
- -- The 'needed' set contains the Ids that are needed by earlier
- -- interface file emissions. If the Id isn't in this set, and isn't
- -- exported, there's no need to emit anything
- 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)
-addExternal (id,rhs) needed
- = extendVarEnv (foldVarSet add_occ needed new_needed_ids)
- id show_unfold
- where
- add_occ id needed = extendVarEnv needed id False
- -- "False" because we don't know we need the Id's unfolding
- -- We'll override it later when we find the binding site
-
- new_needed_ids | opt_OmitInterfacePragmas = emptyVarSet
- | otherwise = worker_ids `unionVarSet`
- unfold_ids `unionVarSet`
- spec_ids
-
- idinfo = idInfo id
- dont_inline = isNeverInlinePrag (inlinePragInfo idinfo)
- loop_breaker = isLoopBreaker (occInfo idinfo)
- bottoming_fn = isBottomingStrictness (strictnessInfo idinfo)
- spec_ids = rulesRhsFreeVars (specInfo idinfo)
- worker_info = workerInfo idinfo
-
- -- Stuff to do with the Id's unfolding
- -- The simplifier has put an up-to-date unfolding
- -- in the IdInfo, but the RHS will do just as well
- unfolding = unfoldingInfo idinfo
- rhs_is_small = not (neverUnfold unfolding)
-
- -- We leave the unfolding there even if there is a worker
- -- In GHCI the unfolding is used by importers
- -- When writing an interface file, we omit the unfolding
- -- if there is a worker
- show_unfold = not bottoming_fn && -- Not necessary
- not dont_inline &&
- not loop_breaker &&
- rhs_is_small && -- Small enough
- okToUnfoldInHiFile rhs -- No casms etc
-
- unfold_ids | show_unfold = exprSomeFreeVars isIdAndLocal rhs
- | otherwise = emptyVarSet
-
- worker_ids = case worker_info of
- HasWorker work_id _ -> unitVarSet work_id
- otherwise -> emptyVarSet
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{Step 2: top-level tidying}
-%* *
-%************************************************************************
-
-
-\begin{code}
-type TopTidyEnv = (UniqSupply, OrigNameNameEnv, TidyOccEnv, VarEnv Var)
-
--- TopTidyEnv: when tidying we need to know
--- * orig_env: 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'
---
--- * 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}
-
-
-\begin{code}
-tidyTopBind :: Module
- -> IdEnv Bool -- Domain = Ids that should be external
- -- True <=> their unfolding is external too
- -> TopTidyEnv -> CoreBind
- -> (TopTidyEnv, CoreBind)
-
-tidyTopBind mod ext_ids env (NonRec bndr rhs)
- = ((us2,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)
-
-tidyTopBind mod ext_ids env (Rec prs)
- = (final_env, Rec prs')
- where
- (final_env@(_,_,occ,subst), prs') = mapAccumL do_one env prs
- final_tidy_env = (occ,subst)
-
- do_one env (bndr,rhs)
- = ((us',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
-
-
-tidyTopBinder :: Module -> IdEnv Bool
- -> TidyEnv -> CoreExpr -> CafInfo
- -- 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 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 second 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
-
- -- The rhs is already tidied
-
- = ((us_r, 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
- is_external
- (idName id)
- ty' = tidyTopType (idType id)
- idinfo' = tidyIdInfo us_l tidy_env
- is_external unfold_info arity_info caf_info id
-
- id' = mkId name' ty' idinfo'
- subst_env' = extendVarEnv subst_env2 id id'
-
- maybe_external = lookupVarEnv ext_ids id
- is_external = maybeToBool 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
- | opt_OmitInterfacePragmas || not is_external
- -- No IdInfo if the Id isn't external, or if we don't have -O
- = mkIdInfo new_flavour
- `setStrictnessInfo` strictnessInfo core_idinfo
- `setArityInfo` ArityExactly arity_info
- `setCafInfo` caf_info
- -- Keep strictness, arity and CAF info; it's used by the code generator
-
- | otherwise
- = let (rules', _) = initUs us (tidyRules tidy_env (specInfo core_idinfo))
- in
- mkIdInfo new_flavour
- `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
- `setCafInfo` caf_info
- -- this is the final IdInfo, it must agree with the
- -- code finally generated (i.e. NO more transformations
- -- after this!).
- 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
-
- | global && external = (orig_env, occ_env, name)
- -- Global names are assumed to have been allocated by the renamer,
- -- so they already have the "right" unique
-
- | 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)
- -- 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
-
------------- 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
- = HasWorker (tidyVarOcc tidy_env work_id) wrap_arity
-tidyWorker tidy_env real_arity other
- = NoWorker
-
------------- Rules --------------
-tidyIdRules :: TidyEnv -> [IdCoreRule] -> UniqSM [IdCoreRule]
-tidyIdRules env [] = returnUs []
-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)
-\end{code}
+This module contains "tidying" code for *nested* expressions, bindings, rules.
+The code for *top-level* bindings is in TidyPgm.
%************************************************************************
%* *
-\subsection{Step 2: inner tidying
+\subsection{Tidying expressions, rules}
%* *
%************************************************************************
\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)
+------------ Expressions --------------
+tidyExpr :: TidyEnv -> CoreExpr -> CoreExpr
+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)
+tidyExpr env (Case e b ty alts)
+ = tidyBndr env b =: \ (env', b) ->
+ Case (tidyExpr env e) b (tidyType env ty)
+ (map (tidyAlt b 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)
+------------ Case alternatives --------------
+tidyAlt case_bndr env (DataAlt con, vs, rhs)
+ | not (isVanillaDataCon con) -- GADT case
+ = tidyBndrs env tvs =: \ (env1, tvs') ->
+ let
+ env2 = refineTidyEnv env con tvs' scrut_ty
+ in
+ tidyBndrs env2 ids =: \ (env3, ids') ->
+ (DataAlt con, tvs' ++ ids', tidyExpr env3 rhs)
+ where
+ (tvs, ids) = span isTyVar vs
+ scrut_ty = idType case_bndr
+
+tidyAlt case_bndr env (con, vs, rhs)
+ = tidyBndrs env vs =: \ (env', vs) ->
+ (con, vs, tidyExpr env' rhs)
+
+refineTidyEnv :: TidyEnv -> DataCon -> [TyVar] -> Type -> TidyEnv
+-- Refine the TidyEnv in the light of the type refinement from coreRefineTys
+refineTidyEnv tidy_env@(occ_env, var_env) con tvs scrut_ty
+ = case coreRefineTys con tvs scrut_ty of
+ Nothing -> tidy_env
+ Just (tv_subst, all_bound_here)
+ | all_bound_here -- Local type refinement only
+ -> tidy_env
+ | otherwise -- Apply the refining subst to the tidy env
+ -- This ensures that occurences have the most refined type
+ -- And that means that exprType will work right everywhere
+ -> (occ_env, mapVarEnv (refine subst) var_env)
+ where
+ subst = mkOpenTvSubst tv_subst
+ where
+ refine subst var | isId var = setIdType var (substTy subst (idType var))
+ | otherwise = var
+------------ Notes --------------
tidyNote env (Coerce t1 t2) = Coerce (tidyType env t1) (tidyType env t2)
tidyNote env note = note
+
+------------ Rules --------------
+tidyRules :: TidyEnv -> [CoreRule] -> [CoreRule]
+tidyRules env [] = []
+tidyRules env (rule : rules)
+ = tidyRule env rule =: \ rule ->
+ tidyRules env rules =: \ rules ->
+ (rule : rules)
+
+tidyRule :: TidyEnv -> CoreRule -> CoreRule
+tidyRule env rule@(BuiltinRule {}) = rule
+tidyRule env rule@(Rule { ru_bndrs = bndrs, ru_args = args, ru_rhs = rhs,
+ ru_fn = fn, ru_rough = mb_ns })
+ = tidyBndrs env bndrs =: \ (env', bndrs) ->
+ map (tidyExpr env') args =: \ args ->
+ rule { ru_bndrs = bndrs, ru_args = args,
+ ru_rhs = tidyExpr env' rhs,
+ ru_fn = tidyNameOcc env fn,
+ ru_rough = map (fmap (tidyNameOcc env')) mb_ns }
\end{code}
%************************************************************************
%* *
-\subsection{Tidying up non-top-level binders}
+\subsection{Tidying non-top-level binders}
%* *
%************************************************************************
\begin{code}
-tidyVarOcc (_, var_env) v = case lookupVarEnv var_env v of
- Just v' -> v'
- Nothing -> v
+tidyNameOcc :: TidyEnv -> Name -> Name
+-- In rules and instances, we have Names, and we must tidy them too
+-- Fortunately, we can lookup in the VarEnv with a name
+tidyNameOcc (_, var_env) n = case lookupUFM var_env n of
+ Nothing -> n
+ Just v -> varName v
+
+tidyVarOcc :: TidyEnv -> Var -> Var
+tidyVarOcc (_, var_env) v = lookupVarEnv var_env v `orElse` 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
+ | isTyVar var = tidyTyVarBndr env var
+ | otherwise = tidyIdBndr env var
-tidyBndrs :: TidyEnv -> [Var] -> UniqSM (TidyEnv, [Var])
-tidyBndrs env vars = mapAccumLUs tidyBndr env vars
+tidyBndrs :: TidyEnv -> [Var] -> (TidyEnv, [Var])
+tidyBndrs env vars = mapAccumL 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
- = -- Non-top-level variables
- getUniqueUs `thenUs` \ uniq ->
+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` exprArity rhs
+ `setAllStrictnessInfo` 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
+
+-- Non-top-level variables
+tidyIdBndr :: TidyEnv -> Id -> (TidyEnv, Id)
+tidyIdBndr env@(tidy_env, var_env) id
+ = -- do this pattern match strictly, otherwise we end up holding on to
+ -- stuff in the OccName.
+ case tidyOccName tidy_env (getOccName id) of { (tidy_env', occ') ->
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
- (tidy_env', occ') = tidyOccName tidy_env (getOccName id)
- ty' = tidyType (tidy_env,var_env) (idType id)
- id' = mkId name' ty' idinfo
+ --
+ -- All nested Ids now have the same IdInfo, namely vanillaIdInfo,
+ -- which should save some space.
+ -- But note that tidyLetBndr puts some of it back.
+ ty' = tidyType env (idType id)
+ id' = mkUserLocal occ' (idUnique id) ty' noSrcLoc
+ `setIdInfo` vanillaIdInfo
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
- -- special case for expressions which are always bottom,
- -- such as 'error "..."'. We don't need to record it as
- -- a CAF, since it can only be entered once.
-isCAF e
- | not_function && is_bottom = False
- | not_function && updatable = True
- | otherwise = False
- where
- not_function = exprArity e == 0
- is_bottom = exprIsBottom e
- updatable = True {- ToDo: check type for onceness? -}
+m =: k = m `seq` k m
\end{code}
projects / ghc-hetmet.git / blobdiff