import FloatIn ( floatInwards )
import FloatOut ( floatOutwards )
import FoldrBuildWW ( mkFoldrBuildWW )
-import Id ( mkSysLocal, setIdVisibility, replaceIdInfo,
- replacePragmaInfo, getIdDemandInfo, idType,
- getIdInfo, getPragmaInfo, mkIdWithNewUniq,
+import MkId ( mkSysLocal, mkUserId )
+import Id ( setIdVisibility, getIdSpecialisation, setIdSpecialisation,
+ getIdDemandInfo, idType,
nullIdEnv, addOneToIdEnv, delOneFromIdEnv,
- lookupIdEnv, IdEnv, omitIfaceSigForId,
- apply_to_Id,
- GenId{-instance Outputable-}, Id
+ lookupIdEnv, IdEnv,
+ Id
)
import IdInfo ( willBeDemanded, DemandInfo )
import Name ( isExported, isLocallyDefined,
isLocalName, uniqToOccName,
+ setNameVisibility,
Module, NamedThing(..), OccName(..)
)
import TyCon ( TyCon )
import LiberateCase ( liberateCase )
import MagicUFs ( MagicUnfoldingFun )
import PprCore
-import PprType ( GenType{-instance Outputable-}, GenTyVar{-ditto-},
- nmbrType
- )
+import PprType ( nmbrType )
import SAT ( doStaticArgs )
import SimplMonad ( zeroSimplCount, showSimplCount, SimplCount )
import SimplPgm ( simplifyPgm )
import Specialise
-import SpecUtils ( pprSpecErrs )
+import SpecEnv ( substSpecEnv, isEmptySpecEnv )
import StrictAnal ( saWwTopBinds )
-import TyVar ( TyVar, nameTyVar )
+import TyVar ( TyVar, nameTyVar, emptyTyVarEnv )
import Unique ( Unique{-instance Eq-}, Uniquable(..),
integerTyConKey, ratioTyConKey,
mkUnique, incrUnique,
import UniqSupply ( UniqSupply, mkSplitUniqSupply,
splitUniqSupply, getUnique
)
-import UniqFM ( UniqFM, lookupUFM, addToUFM )
+import UniqFM ( UniqFM, lookupUFM, addToUFM, delFromUFM )
import Util ( mapAccumL )
import SrcLoc ( noSrcLoc )
import Constants ( tARGET_MIN_INT, tARGET_MAX_INT )
Several tasks are done by @tidyCorePgm@
-1. Eliminate indirections. The point here is to transform
- x_local = E
- x_exported = x_local
- ==>
- x_exported = E
+----------------
+ [March 98] Indirections are now elimianted by the occurrence analyser
+ -- 1. Eliminate indirections. The point here is to transform
+ -- x_local = E
+ -- x_exported = x_local
+ -- ==>
+ -- x_exported = E
2. Make certain top-level bindings into Globals. The point is that
Global things get externally-visible labels at code generation
generator makes global labels from the uniques for local thunks etc.]
-Eliminate indirections
-~~~~~~~~~~~~~~~~~~~~~~
-In @elimIndirections@, we look for things at the top-level of the form...
-\begin{verbatim}
- x_local = ....
- x_exported = x_local
-\end{verbatim}
-In cases we find like this, we go {\em backwards} and replace
-\tr{x_local} with \tr{x_exported}. This save a gratuitous jump
-(from \tr{x_exported} to \tr{x_local}), and makes strictness
-information propagate better.
-
-We rely on prior eta reduction to simplify things like
-\begin{verbatim}
- x_exported = /\ tyvars -> x_local tyvars
-==>
- x_exported = x_local
-\end{verbatim}
-
-If more than one exported thing is equal to a local thing (i.e., the
-local thing really is shared), then we do one only:
-\begin{verbatim}
- x_local = ....
- x_exported1 = x_local
- x_exported2 = x_local
-==>
- x_exported1 = ....
-
- x_exported2 = x_exported1
-\end{verbatim}
-
-There's a possibility of leaving unchanged something like this:
-\begin{verbatim}
- x_local = ....
- x_exported1 = x_local Int
-\end{verbatim}
-By the time we've thrown away the types in STG land this
-could be eliminated. But I don't think it's very common
-and it's dangerous to do this fiddling in STG land
-because we might elminate a binding that's mentioned in the
-unfolding for something.
-
-General Strategy: first collect the info; then make a \tr{Id -> Id} mapping.
-Then blast the whole program (LHSs as well as RHSs) with it.
-
\begin{code}
tidyCorePgm :: Module -> [CoreBinding] -> [CoreBinding]
tidyCorePgm mod binds_in
- = initTM mod indirection_env $
- tidyTopBindings (catMaybes reduced_binds) `thenTM` \ binds ->
+ = initTM mod nullIdEnv $
+ tidyTopBindings binds_in `thenTM` \ binds ->
returnTM (bagToList binds)
- where
- (indirection_env, reduced_binds) = mapAccumL try_bind nullIdEnv binds_in
-
- try_bind :: IdEnv CoreBinder -> CoreBinding -> (IdEnv CoreBinder, Maybe CoreBinding)
- try_bind env_so_far (NonRec exported_binder rhs)
- | isExported exported_binder && -- Only if this is exported
- maybeToBool maybe_rhs_id && -- and the RHS is a simple Id
-
- isLocallyDefined rhs_id && -- Only if this one is defined in this
- -- module, so that we *can* change its
- -- binding to be the exported thing!
-
- not (isExported rhs_id) && -- Only if this one is not itself exported,
- -- since the transformation will nuke it
-
- not (omitIfaceSigForId rhs_id) && -- Don't do the transformation if rhs_id is
- -- something like a constructor, whose
- -- definition is implicitly exported and
- -- which must not vanish.
- -- To illustrate the preceding check consider
- -- data T = MkT Int
- -- mkT = MkT
- -- f x = MkT (x+1)
- -- Here, we'll make a local, non-exported, defn for MkT, and without the
- -- above condition we'll transform it to:
- -- mkT = \x. MkT [x]
- -- f = \y. mkT (y+1)
- -- This is bad because mkT will get the IdDetails of MkT, and won't
- -- be exported. Also the code generator won't make a definition for
- -- the MkT constructor.
- -- Slightly gruesome, this.
-
- not (maybeToBool (lookupIdEnv env_so_far rhs_id))
- -- Only if not already substituted for
-
- = (addOneToIdEnv env_so_far rhs_id (ValBinder new_rhs_id), Nothing)
- where
- maybe_rhs_id = case etaCoreExpr rhs of
- Var rhs_id -> Just rhs_id
- other -> Nothing
- Just rhs_id = maybe_rhs_id
- new_rhs_id = exported_binder `replaceIdInfo` getIdInfo rhs_id
- `replacePragmaInfo` getPragmaInfo rhs_id
- -- NB: we keep the Pragmas and IdInfo for the old rhs_id!
- -- This is important; it might be marked "no-inline" by
- -- the occurrence analyser (because it's recursive), and
- -- we must not lose that information.
-
- try_bind env_so_far bind
- = (env_so_far, Just bind)
\end{code}
Top level bindings
where
(bndrs, rhss) = unzip pairs
-tidyCoreExpr (SCC cc body)
+tidyCoreExpr (Note (Coerce to_ty from_ty) body)
= tidyCoreExprEta body `thenTM` \ body' ->
- returnTM (SCC cc body')
+ tidyTy to_ty `thenTM` \ to_ty' ->
+ tidyTy from_ty `thenTM` \ from_ty' ->
+ returnTM (Note (Coerce to_ty' from_ty') body')
-tidyCoreExpr (Coerce coercion ty body)
+tidyCoreExpr (Note note body)
= tidyCoreExprEta body `thenTM` \ body' ->
- tidyTy ty `thenTM` \ ty' ->
- returnTM (Coerce coercion ty' body')
+ returnTM (Note note body')
-- Wierd case for par, seq, fork etc. See notes above.
tidyCoreExpr (Case scrut@(Prim op args) (PrimAlts _ (BindDefault binder rhs)))
\begin{code}
-- Need to extend the environment when we munge a binder, so that occurrences
--- of the binder will print the correct way (i.e. as a global not a local)
+-- of the binder will print the correct way (e.g. as a global not a local)
mungeTopBinder :: Id -> (Id -> TopTidyM a) -> TopTidyM a
mungeTopBinder id thing_inside mod env us
- = case lookupIdEnv env id of
- Just (ValBinder global) -> thing_inside global mod env us -- Already bound
-
- other -> -- Give it a new print-name unless it's an exported thing
- -- setNameVisibility also does the local/global thing
- let
- (id', us') | isExported id = (id, us)
- | otherwise
- = (setIdVisibility (Just mod) us id,
- incrUnique us)
+ = -- Give it a new print-name unless it's an exported thing
+ -- setNameVisibility also does the local/global thing
+ let
+ (id1, us') | isExported id = (id, us)
+ | otherwise
+ = (setIdVisibility (Just mod) us id,
+ incrUnique us)
+
+ -- Tidy the Id's SpecEnv
+ spec_env = getIdSpecialisation id
+ id2 | isEmptySpecEnv spec_env = id1
+ | otherwise = setIdSpecialisation id1 (tidySpecEnv env spec_env)
+
+ new_env = addToUFM env id (ValBinder id2)
+ in
+ thing_inside id2 mod new_env us'
- new_env = addToUFM env id (ValBinder id')
- in
- thing_inside id' mod new_env us'
+tidySpecEnv env spec_env
+ = substSpecEnv
+ emptyTyVarEnv -- Top level only
+ (tidy_spec_rhs env)
+ spec_env
+ where
+ -- tidy_spec_rhs is another horrid little hacked-up function for
+ -- the RHS of specialisation templates.
+ -- It assumes there is no type substitution.
+ --
+ -- See also SimplVar.substSpecEnvRhs Urgh
+ tidy_spec_rhs env (Var v) = case lookupUFM env v of
+ Just (ValBinder v') -> Var v'
+ Nothing -> Var v
+ tidy_spec_rhs env (App f (VarArg v)) = App (tidy_spec_rhs env f) (case lookupUFM env v of
+ Just (ValBinder v') -> VarArg v'
+ Nothing -> VarArg v)
+ tidy_spec_rhs env (App f arg) = App (tidy_spec_rhs env f) arg
+ tidy_spec_rhs env (Lam b e) = Lam b (tidy_spec_rhs env' e)
+ where
+ env' = case b of
+ ValBinder id -> delFromUFM env id
+ TyBinder _ -> env
mungeTopBinders [] k = k []
mungeTopBinders (b:bs) k = mungeTopBinder b $ \ b' ->
= let
-- Give the Id a fresh print-name, *and* rename its type
local_uniq' = incrUnique local_uniq
- rn_id = setIdVisibility Nothing local_uniq id
- id' = apply_to_Id (nmbr_ty env local_uniq') rn_id
+ name' = setNameVisibility Nothing local_uniq (getName id)
+ ty' = nmbr_ty env local_uniq' (idType id)
+ id' = mkUserId name' ty'
+ -- NB: This throws away the IdInfo of the Id, which we
+ -- no longer need. That means we don't need to
+ -- run over it with env, nor renumber it
+ --
+ -- NB: the Id's unique remains unchanged; it's only
+ -- its print name that is affected by local_uniq
+
env' = addToUFM env id (ValBinder id')
in
thing_inside id' mod env' (gus, local_uniq', floats)
projects / ghc-hetmet.git / blobdiff