%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[SimplCore]{Driver for simplifying @Core@ programs}
#include "HsVersions.h"
-import AnalFBWW ( analFBWW )
-import Bag ( isEmptyBag, foldBag )
-import BinderInfo ( BinderInfo{-instance Outputable-} )
-import CmdLineOpts ( CoreToDo(..), SimplifierSwitch(..), switchIsOn,
- opt_D_show_passes,
+import CmdLineOpts ( CoreToDo(..), SimplifierSwitch(..),
+ SwitchResult, switchIsOn,
+ opt_D_dump_occur_anal,
+ opt_D_dump_simpl_iterations,
opt_D_simplifier_stats,
opt_D_dump_simpl,
opt_D_verbose_core2core,
- opt_DoCoreLinting,
- opt_FoldrBuildOn,
- opt_ReportWhyUnfoldingsDisallowed,
- opt_ShowImportSpecs,
- opt_LiberateCaseThreshold
+ opt_D_dump_occur_anal
)
-import CoreLint ( lintCoreBindings )
+import CoreLint ( beginPass, endPass )
import CoreSyn
-import CoreUtils ( coreExprType )
-import SimplUtils ( etaCoreExpr, typeOkForCase )
+import PprCore ( pprCoreBindings )
+import OccurAnal ( occurAnalyseBinds )
+import CoreUtils ( exprIsTrivial, coreExprType )
+import Simplify ( simplBind )
+import SimplUtils ( etaCoreExpr, findDefault )
+import SimplMonad
import CoreUnfold
-import Literal ( Literal(..), literalType, mkMachInt, mkMachInt_safe )
-import ErrUtils ( ghcExit, dumpIfSet, doIfSet )
-import FiniteMap ( FiniteMap, emptyFM )
+import Const ( Con(..), Literal(..), literalType, mkMachInt )
+import ErrUtils ( dumpIfSet )
import FloatIn ( floatInwards )
import FloatOut ( floatOutwards )
-import FoldrBuildWW ( mkFoldrBuildWW )
-import MkId ( mkSysLocal, mkUserId )
-import Id ( setIdVisibility, getIdSpecialisation, setIdSpecialisation,
- getIdDemandInfo, idType,
- nullIdEnv, addOneToIdEnv, delOneFromIdEnv,
- lookupIdEnv, IdEnv,
- Id
+import Id ( Id, mkSysLocal, mkUserId,
+ setIdVisibility, setIdUnfolding,
+ getIdSpecialisation, setIdSpecialisation,
+ getInlinePragma, setInlinePragma,
+ idType, setIdType
)
-import IdInfo ( willBeDemanded, DemandInfo )
-import Name ( isExported, isLocallyDefined,
- isLocalName, uniqToOccName,
- setNameVisibility,
+import IdInfo ( InlinePragInfo(..) )
+import VarEnv
+import VarSet
+import Name ( isExported, mkSysLocalName,
Module, NamedThing(..), OccName(..)
)
-import TyCon ( TyCon )
+import TyCon ( TyCon, isDataTyCon )
import PrimOp ( PrimOp(..) )
-import PrelVals ( unpackCStringId, unpackCString2Id,
+import PrelInfo ( unpackCStringId, unpackCString2Id,
integerZeroId, integerPlusOneId,
- integerPlusTwoId, integerMinusOneId
+ integerPlusTwoId, integerMinusOneId,
+ int2IntegerId, addr2IntegerId
)
-import Type ( splitAlgTyConApp_maybe, isUnpointedType, Type )
-import TysWiredIn ( stringTy, isIntegerTy )
+import Type ( Type, splitAlgTyConApp_maybe,
+ isUnLiftedType, mkTyVarTy, Type )
+import TysWiredIn ( isIntegerTy )
import LiberateCase ( liberateCase )
-import MagicUFs ( MagicUnfoldingFun )
-import PprCore
import PprType ( nmbrType )
import SAT ( doStaticArgs )
-import SimplMonad ( zeroSimplCount, showSimplCount, SimplCount )
-import SimplPgm ( simplifyPgm )
-import Specialise
-import SpecEnv ( substSpecEnv, isEmptySpecEnv )
+import Specialise ( specProgram)
+import SpecEnv ( specEnvToList, specEnvFromList )
import StrictAnal ( saWwTopBinds )
-import TyVar ( TyVar, nameTyVar, emptyTyVarEnv )
-import Unique ( Unique{-instance Eq-}, Uniquable(..),
- integerTyConKey, ratioTyConKey,
- mkUnique, incrUnique,
- initTidyUniques
+import Var ( TyVar, setTyVarName )
+import Unique ( Unique, Uniquable(..),
+ ratioTyConKey, mkUnique, incrUnique, initTidyUniques
)
-import UniqSupply ( UniqSupply, mkSplitUniqSupply,
- splitUniqSupply, getUnique
- )
-import UniqFM ( UniqFM, lookupUFM, addToUFM, delFromUFM )
-import Util ( mapAccumL )
-import SrcLoc ( noSrcLoc )
+import UniqSupply ( UniqSupply, splitUniqSupply )
import Constants ( tARGET_MIN_INT, tARGET_MAX_INT )
import Bag
import Maybes
\end{code}
\begin{code}
-core2core :: [CoreToDo] -- spec of what core-to-core passes to do
- -> FAST_STRING -- module name (profiling only)
- -> UniqSupply -- a name supply
- -> [TyCon] -- local data tycons and tycon specialisations
- -> [CoreBinding] -- input...
- -> IO [CoreBinding] -- results: program
-
-core2core core_todos module_name us local_tycons binds
- = -- Do the main business
- foldl_mn do_core_pass
- (binds, us, zeroSimplCount)
- core_todos
- >>= \ (processed_binds, us', simpl_stats) ->
+core2core :: [CoreToDo] -- Spec of what core-to-core passes to do
+ -> FAST_STRING -- Module name (profiling only)
+ -> UniqSupply -- A name supply
+ -> [CoreBind] -- Input
+ -> IO [CoreBind] -- Result
+
+core2core core_todos module_name us binds
+ = do
+ -- Do the main business
+ processed_binds <- doCorePasses us binds core_todos
-- Do the final tidy-up
- let
- final_binds = tidyCorePgm module_name processed_binds
- in
- lintCoreBindings "TidyCorePgm" True final_binds >>
+ final_binds <- tidyCorePgm module_name processed_binds
+ -- Return results
+ return final_binds
+
+doCorePasses us binds []
+ = return binds
+
+doCorePasses us binds (to_do : to_dos)
+ = do
+ let (us1, us2) = splitUniqSupply us
+ binds1 <- doCorePass us1 binds to_do
+ doCorePasses us2 binds1 to_dos
+
+doCorePass us binds (CoreDoSimplify sw_chkr) = _scc_ "Simplify" simplifyPgm sw_chkr us binds
+doCorePass us binds CoreLiberateCase = _scc_ "LiberateCase" liberateCase binds
+doCorePass us binds CoreDoFloatInwards = _scc_ "FloatInwards" floatInwards binds
+doCorePass us binds CoreDoFullLaziness = _scc_ "CoreFloating" floatOutwards us binds
+doCorePass us binds CoreDoStaticArgs = _scc_ "CoreStaticArgs" doStaticArgs us binds
+doCorePass us binds CoreDoStrictness = _scc_ "CoreStranal" saWwTopBinds us binds
+doCorePass us binds CoreDoSpecialising = _scc_ "Specialise" specProgram us binds
+\end{code}
- -- Dump output
- dumpIfSet (opt_D_dump_simpl || opt_D_verbose_core2core)
- "Core transformations"
- (pprCoreBindings final_binds) >>
- -- Report statistics
- doIfSet opt_D_simplifier_stats
- (hPutStr stderr ("\nSimplifier Stats:\n") >>
- hPutStr stderr (showSimplCount simpl_stats) >>
- hPutStr stderr "\n") >>
+%************************************************************************
+%* *
+\subsection{The driver for the simplifier}
+%* *
+%************************************************************************
- -- Return results
- return final_binds
+\begin{code}
+simplifyPgm :: (SimplifierSwitch -> SwitchResult)
+ -> UniqSupply
+ -> [CoreBind] -- Input
+ -> IO [CoreBind] -- New bindings
+
+simplifyPgm sw_chkr us binds
+ = do {
+ beginPass "Simplify";
+
+ (termination_msg, it_count, counts, binds') <- iteration us 1 zeroSimplCount binds;
+
+ dumpIfSet opt_D_simplifier_stats "Simplifier statistics"
+ (vcat [text termination_msg <+> text "after" <+> ppr it_count <+> text "iterations",
+ text "",
+ pprSimplCount counts]);
+
+ endPass "Simplify"
+ (opt_D_verbose_core2core && not opt_D_dump_simpl_iterations)
+ binds'
+ }
where
- --------------
- do_core_pass info@(binds, us, simpl_stats) to_do =
- case (splitUniqSupply us) of
- (us1,us2) ->
- case to_do of
- CoreDoSimplify simpl_sw_chkr
- -> _scc_ "CoreSimplify"
- begin_pass ("Simplify" ++ if switchIsOn simpl_sw_chkr SimplDoFoldrBuild
- then " (foldr/build)" else "") >>
- case (simplifyPgm binds simpl_sw_chkr simpl_stats us1) of
- (p, it_cnt, simpl_stats2)
- -> end_pass us2 p simpl_stats2
- ("Simplify (" ++ show it_cnt ++ ")"
- ++ if switchIsOn simpl_sw_chkr SimplDoFoldrBuild
- then " foldr/build" else "")
-
- CoreDoFoldrBuildWorkerWrapper
- -> _scc_ "CoreDoFoldrBuildWorkerWrapper"
- begin_pass "FBWW" >>
- case (mkFoldrBuildWW us1 binds) of { binds2 ->
- end_pass us2 binds2 simpl_stats "FBWW" }
-
- CoreDoFoldrBuildWWAnal
- -> _scc_ "CoreDoFoldrBuildWWAnal"
- begin_pass "AnalFBWW" >>
- case (analFBWW binds) of { binds2 ->
- end_pass us2 binds2 simpl_stats "AnalFBWW" }
-
- CoreLiberateCase
- -> _scc_ "LiberateCase"
- begin_pass "LiberateCase" >>
- case (liberateCase opt_LiberateCaseThreshold binds) of { binds2 ->
- end_pass us2 binds2 simpl_stats "LiberateCase" }
-
- CoreDoFloatInwards
- -> _scc_ "FloatInwards"
- begin_pass "FloatIn" >>
- case (floatInwards binds) of { binds2 ->
- end_pass us2 binds2 simpl_stats "FloatIn" }
-
- CoreDoFullLaziness
- -> _scc_ "CoreFloating"
- begin_pass "FloatOut" >>
- case (floatOutwards us1 binds) of { binds2 ->
- end_pass us2 binds2 simpl_stats "FloatOut" }
-
- CoreDoStaticArgs
- -> _scc_ "CoreStaticArgs"
- begin_pass "StaticArgs" >>
- case (doStaticArgs binds us1) of { binds2 ->
- end_pass us2 binds2 simpl_stats "StaticArgs" }
- -- Binds really should be dependency-analysed for static-
- -- arg transformation... Not to worry, they probably are.
- -- (I don't think it *dies* if they aren't [WDP 94/04/15])
-
- CoreDoStrictness
- -> _scc_ "CoreStranal"
- begin_pass "StrAnal" >>
- case (saWwTopBinds us1 binds) of { binds2 ->
- end_pass us2 binds2 simpl_stats "StrAnal" }
-
- CoreDoSpecialising
- -> _scc_ "Specialise"
- begin_pass "Specialise" >>
- case (specProgram us1 binds) of { p ->
- end_pass us2 p simpl_stats "Specialise"
- }
-
- CoreDoPrintCore -- print result of last pass
- -> dumpIfSet (not opt_D_verbose_core2core) "Print Core"
- (pprCoreBindings binds) >>
- return (binds, us1, simpl_stats)
-
- -------------------------------------------------
-
- begin_pass what
- = if opt_D_show_passes
- then hPutStr stderr ("*** Core2Core: "++what++"\n")
- else return ()
-
- end_pass us2 binds2
- simpl_stats2 what
- = -- Report verbosely, if required
- dumpIfSet opt_D_verbose_core2core what
- (pprCoreBindings binds2) >>
-
- lintCoreBindings what True {- spec_done -} binds2 >>
- -- The spec_done flag tells the linter to
- -- complain about unboxed let-bindings
- -- But we're not specialising unboxed types any more,
- -- so its irrelevant.
-
- return
- (binds2, -- processed binds, possibly run thru CoreLint
- us2, -- UniqSupply for the next guy
- simpl_stats2 -- accumulated simplifier stats
- )
-
-
--- here so it can be inlined...
-foldl_mn f z [] = return z
-foldl_mn f z (x:xs) = f z x >>= \ zz ->
- foldl_mn f zz xs
+ max_iterations = getSimplIntSwitch sw_chkr MaxSimplifierIterations
+ simpl_switch_is_on = switchIsOn sw_chkr
+
+ core_iter_dump binds | opt_D_verbose_core2core = pprCoreBindings binds
+ | otherwise = empty
+
+ iteration us iteration_no counts binds
+ = do {
+ -- Occurrence analysis
+ let { tagged_binds = _scc_ "OccAnal" occurAnalyseBinds simpl_switch_is_on binds };
+ dumpIfSet opt_D_dump_occur_anal "Occurrence analysis"
+ (pprCoreBindings tagged_binds);
+
+ -- Simplify
+ let { (binds', counts') = initSmpl sw_chkr us1 (simplTopBinds tagged_binds);
+ all_counts = counts `plusSimplCount` counts'
+ } ;
+
+ -- Stop if nothing happened; don't dump output
+ if isZeroSimplCount counts' then
+ return ("Simplifier reached fixed point", iteration_no, all_counts, binds')
+ else do {
+
+ -- Dump the result of this iteration
+ dumpIfSet opt_D_dump_simpl_iterations
+ ("Simplifier iteration " ++ show iteration_no
+ ++ " out of " ++ show max_iterations)
+ (vcat[pprSimplCount counts',
+ text "",
+ core_iter_dump binds']) ;
+
+ -- Stop if we've run out of iterations
+ if iteration_no == max_iterations then
+ do {
+ if max_iterations > 1 then
+ hPutStr stderr ("NOTE: Simplifier still going after " ++
+ show max_iterations ++
+ " iterations; bailing out.\n")
+ else return ();
+
+ return ("Simplifier baled out", iteration_no, all_counts, binds')
+ }
+
+ -- Else loop
+ else iteration us2 (iteration_no + 1) all_counts binds'
+ } }
+ where
+ (us1, us2) = splitUniqSupply us
+
+
+simplTopBinds [] = returnSmpl []
+simplTopBinds (bind1 : binds) = (simplBind bind1 $
+ simplTopBinds binds) `thenSmpl` \ (binds1', binds') ->
+ returnSmpl (binds1' ++ binds')
\end{code}
-
%************************************************************************
%* *
\subsection[SimplCore-indirections]{Eliminating indirections in Core code, and globalising}
time
3. Make the representation of NoRep literals explicit, and
- float their bindings to the top level
-
+ float their bindings to the top level. We only do the floating
+ part for NoRep lits inside a lambda (else no gain). We need to
+ take care with let x = "foo" in e
+ that we don't end up with a silly binding
+ let x = y in e
+ with a floated "foo". What a bore.
+
4. Convert
case x of {...; x' -> ...x'...}
==>
case x of {...; _ -> ...x... }
See notes in SimplCase.lhs, near simplDefault for the reasoning here.
-5. *Mangle* cases involving fork# and par# in the discriminant. The
- original templates for these primops (see @PrelVals.lhs@) constructed
- case expressions with boolean results solely to fool the strictness
- analyzer, the simplifier, and anyone else who might want to fool with
- the evaluation order. At this point in the compiler our evaluation
- order is safe. Therefore, we convert expressions of the form:
+5. *Mangle* cases involving par# in the discriminant. The unfolding
+ for par in PrelConc.lhs include case expressions with integer
+ results solely to fool the strictness analyzer, the simplifier,
+ and anyone else who might want to fool with the evaluation order.
+ At this point in the compiler our evaluation order is safe.
+ Therefore, we convert expressions of the form:
case par# e of
- True -> rhs
- False -> parError#
+ 0# -> rhs
+ _ -> parError#
==>
case par# e of
_ -> rhs
-6. Eliminate polymorphic case expressions. We can't generate code for them yet.
+ fork# isn't handled like this - it's an explicit IO operation now.
+ The reason is that fork# returns a ThreadId#, which gets in the
+ way of the above scheme. And anyway, IO is the only guaranteed
+ way to enforce ordering --SDM.
+
+6. Mangle cases involving seq# in the discriminant. Up to this
+ point, seq# will appear like this:
+
+ case seq# e of
+ 0# -> seqError#
+ _ -> ...
+
+ where the 0# branch is purely to bamboozle the strictness analyser
+ (see case 5 above). This code comes from an unfolding for 'seq'
+ in Prelude.hs. We translate this into
+
+ case e of
+ _ -> ...
+
+ Now that the evaluation order is safe. The code generator knows
+ how to push a seq frame on the stack if 'e' is of function type,
+ or is polymorphic.
+
+
+7. Do eta reduction for lambda abstractions appearing in:
+ - the RHS of case alternatives
+ - the body of a let
+
+ These will otherwise turn into local bindings during Core->STG;
+ better to nuke them if possible. (In general the simplifier does
+ eta expansion not eta reduction, up to this point.)
-7. Do eta reduction for lambda abstractions appearing in:
- - the RHS of case alternatives
- - the body of a let
- These will otherwise turn into local bindings during Core->STG; better to
- nuke them if possible. (In general the simplifier does eta expansion not
- eta reduction, up to this point.)
+9. Give all binders a nice print-name. Their uniques aren't changed;
+ rather we give them lexically unique occ-names, so that we can
+ safely print the OccNae only in the interface file. [Bad idea to
+ change the uniques, because the code generator makes global labels
+ from the uniques for local thunks etc.]
-8. Do let-to-case. See notes in Simplify.lhs for why we defer let-to-case
- for multi-constructor types.
-9. Give all binders a nice print-name. Their uniques aren't changed; rather we give
- them lexically unique occ-names, so that we can safely print the OccNae only
- in the interface file. [Bad idea to change the uniques, because the code
- generator makes global labels from the uniques for local thunks etc.]
+Special case
+~~~~~~~~~~~~
+NOT ENABLED AT THE MOMENT (because the floated Ids are global-ish
+things, and we need local Ids for non-floated stuff):
+ Don't float stuff out of a binder that's marked as a bottoming Id.
+ Reason: it doesn't do any good, and creates more CAFs that increase
+ the size of SRTs.
+
+eg.
+
+ f = error "string"
+
+is translated to
+
+ f' = unpackCString# "string"
+ f = error f'
+
+hence f' and f become CAFs. Instead, the special case for
+tidyTopBinding below makes sure this comes out as
+
+ f = let f' = unpackCString# "string" in error f'
+
+and we can safely ignore f as a CAF, since it can only ever be entered once.
\begin{code}
-tidyCorePgm :: Module -> [CoreBinding] -> [CoreBinding]
+tidyCorePgm :: Module -> [CoreBind] -> IO [CoreBind]
tidyCorePgm mod binds_in
- = initTM mod nullIdEnv $
- tidyTopBindings binds_in `thenTM` \ binds ->
- returnTM (bagToList binds)
+ = do
+ beginPass "Tidy Core"
+
+ let binds_out = bagToList (initTM mod (tidyTopBindings binds_in))
+
+ endPass "Tidy Core" (opt_D_dump_simpl || opt_D_verbose_core2core) binds_out
\end{code}
Top level bindings
= tidyTopBinding b $
tidyTopBindings bs
-tidyTopBinding :: CoreBinding
- -> TopTidyM (Bag CoreBinding)
- -> TopTidyM (Bag CoreBinding)
+tidyTopBinding :: CoreBind
+ -> TopTidyM (Bag CoreBind)
+ -> TopTidyM (Bag CoreBind)
tidyTopBinding (NonRec bndr rhs) thing_inside
= initNestedTM (tidyCoreExpr rhs) `thenTM` \ (rhs',floats) ->
- mungeTopBinder bndr $ \ bndr' ->
+ tidyTopBinder bndr $ \ bndr' ->
thing_inside `thenTM` \ binds ->
- returnTM ((floats `snocBag` NonRec bndr' rhs') `unionBags` binds)
+ let
+ this_bind {- | isBottomingId bndr
+ = unitBag (NonRec bndr' (foldrBag Let rhs' floats))
+ | otherwise -}
+ = floats `snocBag` NonRec bndr' rhs'
+ in
+ returnTM (this_bind `unionBags` binds)
tidyTopBinding (Rec pairs) thing_inside
- = mungeTopBinders binders $ \ binders' ->
+ = tidyTopBinders binders $ \ binders' ->
initNestedTM (mapTM tidyCoreExpr rhss) `thenTM` \ (rhss', floats) ->
thing_inside `thenTM` \ binds_inside ->
returnTM ((floats `snocBag` Rec (binders' `zip` rhss')) `unionBags` binds_inside)
(binders, rhss) = unzip pairs
\end{code}
+\begin{code}
+tidyTopBinder :: Id -> (Id -> TopTidyM (Bag CoreBind)) -> TopTidyM (Bag CoreBind)
+tidyTopBinder id thing_inside
+ = mungeTopBndr id $ \ id' ->
+ let
+ spec_items = specEnvToList (getIdSpecialisation id')
+ in
+ if null spec_items then
+
+ -- Common case, no specialisations to tidy
+ thing_inside id'
+ else
+ -- Oh well, tidy those specialisations
+ initNestedTM (mapTM tidySpecItem spec_items) `thenTM` \ (spec_items', floats) ->
+ let
+ id'' = setIdSpecialisation id' (specEnvFromList spec_items')
+ in
+ extendEnvTM id (Var id'') $
+ thing_inside id'' `thenTM` \ binds ->
+ returnTM (floats `unionBags` binds)
+
+tidyTopBinders [] k = k []
+tidyTopBinders (b:bs) k = tidyTopBinder b $ \ b' ->
+ tidyTopBinders bs $ \ bs' ->
+ k (b' : bs')
+
+tidySpecItem (tyvars, tys, rhs)
+ = newBndrs tyvars $ \ tyvars' ->
+ mapTM tidyTy tys `thenTM` \ tys' ->
+ tidyCoreExpr rhs `thenTM` \ rhs' ->
+ returnTM (tyvars', tys', rhs')
+\end{code}
Expressions
~~~~~~~~~~~
\begin{code}
-tidyCoreExpr (Var v) = lookupId v `thenTM` \ v' ->
- returnTM (Var v')
+tidyCoreExpr (Var v) = lookupId v
-tidyCoreExpr (Lit lit)
- = litToRep lit `thenTM` \ (_, lit_expr) ->
- returnTM lit_expr
+tidyCoreExpr (Type ty)
+ = tidyTy ty `thenTM` \ ty' ->
+ returnTM (Type ty')
tidyCoreExpr (App fun arg)
= tidyCoreExpr fun `thenTM` \ fun' ->
- tidyCoreArg arg `thenTM` \ arg' ->
+ tidyCoreExpr arg `thenTM` \ arg' ->
returnTM (App fun' arg')
+tidyCoreExpr (Con (Literal lit) args)
+ = ASSERT( null args )
+ litToRep lit `thenTM` \ (lit_ty, lit_expr) ->
+ getInsideLambda `thenTM` \ in_lam ->
+ if in_lam && not (exprIsTrivial lit_expr) then
+ -- It must have been a no-rep literal with a
+ -- non-trivial representation; and we're inside a lambda;
+ -- so float it to the top
+ addTopFloat lit_ty lit_expr `thenTM` \ v ->
+ returnTM (Var v)
+ else
+ returnTM lit_expr
+
tidyCoreExpr (Con con args)
- = mapTM tidyCoreArg args `thenTM` \ args' ->
+ = mapTM tidyCoreExpr args `thenTM` \ args' ->
returnTM (Con con args')
-tidyCoreExpr (Prim prim args)
- = tidyPrimOp prim `thenTM` \ prim' ->
- mapTM tidyCoreArg args `thenTM` \ args' ->
- returnTM (Prim prim' args')
-
-tidyCoreExpr (Lam (ValBinder v) body)
- = newId v $ \ v' ->
+tidyCoreExpr (Lam bndr body)
+ = newBndr bndr $ \ bndr' ->
+ insideLambda bndr $
tidyCoreExpr body `thenTM` \ body' ->
- returnTM (Lam (ValBinder v') body')
-
-tidyCoreExpr (Lam (TyBinder tv) body)
- = newTyVar tv $ \ tv' ->
- tidyCoreExpr body `thenTM` \ body' ->
- returnTM (Lam (TyBinder tv') body')
-
- -- Try for let-to-case (see notes in Simplify.lhs for why
- -- some let-to-case stuff is deferred to now).
-tidyCoreExpr (Let (NonRec bndr rhs) body)
- | willBeDemanded (getIdDemandInfo bndr) &&
- not rhs_is_whnf && -- Don't do it if RHS is already in WHNF
- typeOkForCase (idType bndr)
- = ASSERT( not (isUnpointedType (idType bndr)) )
- tidyCoreExpr (Case rhs (AlgAlts [] (BindDefault bndr body)))
- where
- rhs_is_whnf = case mkFormSummary rhs of
- VarForm -> True
- ValueForm -> True
- other -> False
+ returnTM (Lam bndr' body')
tidyCoreExpr (Let (NonRec bndr rhs) body)
= tidyCoreExpr rhs `thenTM` \ rhs' ->
- newId bndr $ \ bndr' ->
- tidyCoreExprEta body `thenTM` \ body' ->
- returnTM (Let (NonRec bndr' rhs') body')
+ tidyBindNonRec bndr rhs' body
tidyCoreExpr (Let (Rec pairs) body)
- = newIds bndrs $ \ bndrs' ->
+ = newBndrs bndrs $ \ bndrs' ->
mapTM tidyCoreExpr rhss `thenTM` \ rhss' ->
tidyCoreExprEta body `thenTM` \ body' ->
returnTM (Let (Rec (bndrs' `zip` rhss')) body')
= tidyCoreExprEta body `thenTM` \ 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)))
- | funnyParallelOp op
+-- seq#: see notes above.
+tidyCoreExpr (Case scrut@(Con (PrimOp SeqOp) [Type _, e]) bndr alts)
+ = tidyCoreExpr e `thenTM` \ e' ->
+ newBndr bndr $ \ bndr' ->
+ let new_bndr = setIdType bndr' (coreExprType e') in
+ tidyCoreExprEta default_rhs `thenTM` \ rhs' ->
+ returnTM (Case e' new_bndr [(DEFAULT,[],rhs')])
+ where
+ (other_alts, maybe_default) = findDefault alts
+ Just default_rhs = maybe_default
+
+-- par#: see notes above.
+tidyCoreExpr (Case scrut@(Con (PrimOp op) args) bndr alts)
+ | funnyParallelOp op && maybeToBool maybe_default
= tidyCoreExpr scrut `thenTM` \ scrut' ->
- newId binder $ \ binder' ->
- tidyCoreExprEta rhs `thenTM` \ rhs' ->
- returnTM (Case scrut' (PrimAlts [] (BindDefault binder' rhs')))
-
--- Eliminate polymorphic case, for which we can't generate code just yet
-tidyCoreExpr (Case scrut (AlgAlts [] (BindDefault deflt_bndr rhs)))
- | not (typeOkForCase (idType deflt_bndr))
- = pprTrace "Warning: discarding polymorphic case:" (ppr scrut) $
- case scrut of
- Var v -> lookupId v `thenTM` \ v' ->
- extendEnvTM deflt_bndr v' (tidyCoreExpr rhs)
- other -> tidyCoreExpr (Let (NonRec deflt_bndr scrut) rhs)
-
-tidyCoreExpr (Case scrut alts)
+ newBndr bndr $ \ bndr' ->
+ tidyCoreExprEta default_rhs `thenTM` \ rhs' ->
+ returnTM (Case scrut' bndr' [(DEFAULT,[],rhs')])
+ where
+ (other_alts, maybe_default) = findDefault alts
+ Just default_rhs = maybe_default
+
+tidyCoreExpr (Case scrut case_bndr alts)
= tidyCoreExpr scrut `thenTM` \ scrut' ->
- tidy_alts scrut' alts `thenTM` \ alts' ->
- returnTM (Case scrut' alts')
+ newBndr case_bndr $ \ case_bndr' ->
+ mapTM tidy_alt alts `thenTM` \ alts' ->
+ returnTM (Case scrut' case_bndr' alts')
where
- tidy_alts scrut (AlgAlts alts deflt)
- = mapTM tidy_alg_alt alts `thenTM` \ alts' ->
- tidy_deflt scrut deflt `thenTM` \ deflt' ->
- returnTM (AlgAlts alts' deflt')
-
- tidy_alts scrut (PrimAlts alts deflt)
- = mapTM tidy_prim_alt alts `thenTM` \ alts' ->
- tidy_deflt scrut deflt `thenTM` \ deflt' ->
- returnTM (PrimAlts alts' deflt')
-
- tidy_alg_alt (con,bndrs,rhs) = newIds bndrs $ \ bndrs' ->
- tidyCoreExprEta rhs `thenTM` \ rhs' ->
- returnTM (con, bndrs', rhs')
-
- tidy_prim_alt (lit,rhs) = tidyCoreExprEta rhs `thenTM` \ rhs' ->
- returnTM (lit,rhs')
-
- -- We convert case x of {...; x' -> ...x'...}
- -- to
- -- case x of {...; _ -> ...x... }
- --
- -- See notes in SimplCase.lhs, near simplDefault for the reasoning.
- -- It's quite easily done: simply extend the environment to bind the
- -- default binder to the scrutinee.
-
- tidy_deflt scrut NoDefault = returnTM NoDefault
- tidy_deflt scrut (BindDefault bndr rhs)
- = newId bndr $ \ bndr' ->
- extend_env (tidyCoreExprEta rhs) `thenTM` \ rhs' ->
- returnTM (BindDefault bndr' rhs')
- where
- extend_env = case scrut of
- Var v -> extendEnvTM bndr v
- other -> \x -> x
+ tidy_alt (con,bndrs,rhs) = newBndrs bndrs $ \ bndrs' ->
+ tidyCoreExprEta rhs `thenTM` \ rhs' ->
+ returnTM (con, bndrs', rhs')
tidyCoreExprEta e = tidyCoreExpr e `thenTM` \ e' ->
returnTM (etaCoreExpr e')
-\end{code}
-
-Arguments
-~~~~~~~~~
-\begin{code}
-tidyCoreArg :: CoreArg -> NestTidyM CoreArg
-
-tidyCoreArg (VarArg v)
- = lookupId v `thenTM` \ v' ->
- returnTM (VarArg v')
-
-tidyCoreArg (LitArg lit)
- = litToRep lit `thenTM` \ (lit_ty, lit_expr) ->
- case lit_expr of
- Var v -> returnTM (VarArg v)
- Lit l -> returnTM (LitArg l)
- other -> addTopFloat lit_ty lit_expr `thenTM` \ v ->
- returnTM (VarArg v)
-
-tidyCoreArg (TyArg ty) = tidyTy ty `thenTM` \ ty' ->
- returnTM (TyArg ty')
-\end{code}
-\begin{code}
-tidyPrimOp (CCallOp fn casm gc cconv tys ty)
- = mapTM tidyTy tys `thenTM` \ tys' ->
- tidyTy ty `thenTM` \ ty' ->
- returnTM (CCallOp fn casm gc cconv tys' ty')
+tidyBindNonRec bndr val' body
+ | exprIsTrivial val'
+ = extendEnvTM bndr val' (tidyCoreExpr body)
-tidyPrimOp other_prim_op = returnTM other_prim_op
-\end{code}
+ | otherwise
+ = newBndr bndr $ \ bndr' ->
+ tidyCoreExpr body `thenTM` \ body' ->
+ returnTM (Let (NonRec bndr' val') body')
+\end{code}
%************************************************************************
litToRep :: Literal -> NestTidyM (Type, CoreExpr)
-litToRep (NoRepStr s)
- = returnTM (stringTy, rhs)
+litToRep (NoRepStr s ty)
+ = returnTM (ty, rhs)
where
rhs = if (any is_NUL (_UNPK_ s))
then -- Must cater for NULs in literal string
- mkGenApp (Var unpackCString2Id)
- [LitArg (MachStr s),
- LitArg (mkMachInt_safe (toInteger (_LENGTH_ s)))]
+ mkApps (Var unpackCString2Id)
+ [mkLit (MachStr s),
+ mkLit (mkMachInt (toInteger (_LENGTH_ s)))]
else -- No NULs in the string
- App (Var unpackCStringId) (LitArg (MachStr s))
+ App (Var unpackCStringId) (mkLit (MachStr s))
is_NUL c = c == '\0'
\end{code}
litToRep (NoRepInteger i integer_ty)
= returnTM (integer_ty, rhs)
where
- rhs | i == 0 = Var integerZeroId -- Extremely convenient to look out for
- | i == 1 = Var integerPlusOneId -- a few very common Integer literals!
+ rhs | i == 0 = Var integerZeroId -- Extremely convenient to look out for
+ | i == 1 = Var integerPlusOneId -- a few very common Integer literals!
| i == 2 = Var integerPlusTwoId
| i == (-1) = Var integerMinusOneId
| i > tARGET_MIN_INT && -- Small enough, so start from an Int
i < tARGET_MAX_INT
- = Prim Int2IntegerOp [LitArg (mkMachInt (fromInteger i))]
+ = App (Var int2IntegerId) (Con (Literal (mkMachInt i)) [])
| otherwise -- Big, so start from a string
- = Prim Addr2IntegerOp [LitArg (MachStr (_PK_ (show i)))]
+ = App (Var addr2IntegerId) (Con (Literal (MachStr (_PK_ (show i)))) [])
litToRep (NoRepRational r rational_ty)
- = tidyCoreArg (LitArg (NoRepInteger (numerator r) integer_ty)) `thenTM` \ num_arg ->
- tidyCoreArg (LitArg (NoRepInteger (denominator r) integer_ty)) `thenTM` \ denom_arg ->
- returnTM (rational_ty, Con ratio_data_con [TyArg integer_ty, num_arg, denom_arg])
+ = tidyCoreExpr (mkLit (NoRepInteger (numerator r) integer_ty)) `thenTM` \ num_arg ->
+ tidyCoreExpr (mkLit (NoRepInteger (denominator r) integer_ty)) `thenTM` \ denom_arg ->
+ returnTM (rational_ty, mkConApp ratio_data_con [Type integer_ty, num_arg, denom_arg])
where
(ratio_data_con, integer_ty)
= case (splitAlgTyConApp_maybe rational_ty) of
Just (tycon, [i_ty], [con])
- -> ASSERT(isIntegerTy i_ty && uniqueOf tycon == ratioTyConKey)
+ -> ASSERT(isIntegerTy i_ty && getUnique tycon == ratioTyConKey)
(con, i_ty)
_ -> (panic "ratio_data_con", panic "integer_ty")
-litToRep other_lit = returnTM (literalType other_lit, Lit other_lit)
+litToRep other_lit = returnTM (literalType other_lit, mkLit other_lit)
\end{code}
\begin{code}
-funnyParallelOp SeqOp = True
funnyParallelOp ParOp = True
-funnyParallelOp ForkOp = True
funnyParallelOp _ = False
\end{code}
\begin{code}
type TidyM a state = Module
- -> UniqFM CoreBinder -- Maps Ids to Ids, TyVars to TyVars etc
+ -> Bool -- True <=> inside a *value* lambda
+ -> (TyVarEnv Type, IdEnv CoreExpr, IdOrTyVarSet)
+ -- Substitution and in-scope binders
-> state
-> (a, state)
type TopTidyM a = TidyM a Unique
type NestTidyM a = TidyM a (Unique, -- Global names
Unique, -- Local names
- Bag CoreBinding) -- Floats
+ Bag CoreBind) -- Floats
(initialTopTidyUnique, initialNestedTidyUnique) = initTidyUniques
-initTM :: Module -> UniqFM CoreBinder -> TopTidyM a -> a
-initTM mod env m
- = case m mod env initialTopTidyUnique of
+initTM :: Module -> TopTidyM a -> a
+initTM mod m
+ = case m mod False {- not inside lambda -} empty_env initialTopTidyUnique of
(result, _) -> result
+ where
+ empty_env = (emptyVarEnv, emptyVarEnv, emptyVarSet)
-initNestedTM :: NestTidyM a -> TopTidyM (a, Bag CoreBinding)
-initNestedTM m mod env global_us
- = case m mod env (global_us, initialNestedTidyUnique, emptyBag) of
+initNestedTM :: NestTidyM a -> TopTidyM (a, Bag CoreBind)
+initNestedTM m mod in_lam env global_us
+ = case m mod in_lam env (global_us, initialNestedTidyUnique, emptyBag) of
(result, (global_us', _, floats)) -> ((result, floats), global_us')
-returnTM v mod env usf = (v, usf)
-thenTM m k mod env usf = case m mod env usf of
- (r, usf') -> k r mod env usf'
+returnTM v mod in_lam env usf = (v, usf)
+thenTM m k mod in_lam env usf = case m mod in_lam env usf of
+ (r, usf') -> k r mod in_lam env usf'
mapTM f [] = returnTM []
-mapTM f (x:xs) = f x `thenTM` \ r ->
+mapTM f (x:xs) = f x `thenTM` \ r ->
mapTM f xs `thenTM` \ rs ->
returnTM (r:rs)
-\end{code}
+insideLambda :: CoreBndr -> NestTidyM a -> NestTidyM a
+insideLambda bndr m mod in_lam env usf | isId bndr = m mod True env usf
+ | otherwise = m mod in_lam env usf
-\begin{code}
--- Need to extend the environment when we munge a binder, so that occurrences
--- 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
- = -- 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)
+getInsideLambda :: NestTidyM Bool
+getInsideLambda mod in_lam env usf = (in_lam, usf)
+\end{code}
- -- Tidy the Id's SpecEnv
- spec_env = getIdSpecialisation id
- id2 | isEmptySpecEnv spec_env = id1
- | otherwise = setIdSpecialisation id1 (tidySpecEnv env spec_env)
+Need to extend the environment when we munge a binder, so that
+occurrences of the binder will print the correct way (e.g. as a global
+not a local).
- new_env = addToUFM env id (ValBinder id2)
- in
- thing_inside id2 mod new_env us'
+In cases where we don't clone the binder (because it's an exported
+id), we still zap the unfolding and inline pragma info so that
+unnecessary gumph isn't carried into the code generator. This fixes a
+nasty space leak.
-tidySpecEnv env spec_env
- = substSpecEnv
- emptyTyVarEnv -- Top level only
- (tidy_spec_rhs env)
- spec_env
+\begin{code}
+mungeTopBndr id thing_inside mod in_lam env@(ty_env, val_env, in_scope) us
+ = thing_inside id' mod in_lam (ty_env, val_env', in_scope') us'
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' ->
- mungeTopBinders bs $ \ bs' ->
- k (b' : bs')
+ (id', us') | isExported id = (zapSomeIdInfo id, us)
+ | otherwise = (zapSomeIdInfo (setIdVisibility (Just mod) us id),
+ incrUnique us)
+ val_env' = extendVarEnv val_env id (Var id')
+ in_scope' = extendVarSet in_scope id'
+
+zapSomeIdInfo id = id `setIdUnfolding` noUnfolding `setInlinePragma` new_ip
+ where new_ip = case getInlinePragma id of
+ ICanSafelyBeINLINEd _ _ -> NoInlinePragInfo
+ something_else -> something_else
addTopFloat :: Type -> CoreExpr -> NestTidyM Id
-addTopFloat lit_ty lit_rhs mod env (gus, lus, floats)
+addTopFloat lit_ty lit_rhs mod in_lam env (gus, lus, floats)
= let
gus' = incrUnique gus
- lit_local = mkSysLocal SLIT("lit") gus lit_ty noSrcLoc
+ lit_local = mkSysLocal gus lit_ty
lit_id = setIdVisibility (Just mod) gus lit_local
in
(lit_id, (gus', lus, floats `snocBag` NonRec lit_id lit_rhs))
-lookupId :: Id -> TidyM Id state
-lookupId v mod env usf
- = case lookupUFM env v of
- Nothing -> (v, usf)
- Just (ValBinder v') -> (v', usf)
+lookupId :: Id -> TidyM CoreExpr state
+lookupId v mod in_lam (_, val_env, _) usf
+ = case lookupVarEnv val_env v of
+ Nothing -> (Var v, usf)
+ Just e -> (e, usf)
-extendEnvTM :: Id -> Id -> (TidyM a state) -> TidyM a state
-extendEnvTM v v' m mod env usf
- = m mod (addOneToIdEnv env v (ValBinder v')) usf
+extendEnvTM :: Id -> CoreExpr -> (TidyM a state) -> TidyM a state
+extendEnvTM v e m mod in_lam (ty_env, val_env, in_scope) usf
+ = m mod in_lam (ty_env, extendVarEnv val_env v e, in_scope) usf
\end{code}
Making new local binders
~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
-newId id thing_inside mod env (gus, local_uniq, floats)
+newBndr tyvar thing_inside mod in_lam (ty_env, val_env, in_scope) (gus, local_uniq, floats)
+ | isTyVar tyvar
+ = let
+ local_uniq' = incrUnique local_uniq
+ tyvar' = setTyVarName tyvar (mkSysLocalName local_uniq)
+ ty_env' = extendVarEnv ty_env tyvar (mkTyVarTy tyvar')
+ in_scope' = extendVarSet in_scope tyvar'
+ in
+ thing_inside tyvar' mod in_lam (ty_env', val_env, in_scope') (gus, local_uniq', floats)
+
+newBndr id thing_inside mod in_lam (ty_env, val_env, in_scope) (gus, local_uniq, floats)
+ | isId id
= let
-- Give the Id a fresh print-name, *and* rename its type
local_uniq' = incrUnique local_uniq
- name' = setNameVisibility Nothing local_uniq (getName id)
- ty' = nmbr_ty env local_uniq' (idType id)
+ name' = mkSysLocalName local_uniq
+ ty' = nmbrType 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')
+ -- 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.
+
+ val_env' = extendVarEnv val_env id (Var id')
+ in_scope' = extendVarSet in_scope id'
in
- thing_inside id' mod env' (gus, local_uniq', floats)
+ thing_inside id' mod in_lam (ty_env, val_env', in_scope') (gus, local_uniq', floats)
-newIds [] thing_inside
+newBndrs [] thing_inside
= thing_inside []
-newIds (bndr:bndrs) thing_inside
- = newId bndr $ \ bndr' ->
- newIds bndrs $ \ bndrs' ->
+newBndrs (bndr:bndrs) thing_inside
+ = newBndr bndr $ \ bndr' ->
+ newBndrs bndrs $ \ bndrs' ->
thing_inside (bndr' : bndrs')
-
-
-newTyVar tyvar thing_inside mod env (gus, local_uniq, floats)
- = let
- local_uniq' = incrUnique local_uniq
- tyvar' = nameTyVar tyvar (uniqToOccName local_uniq)
- env' = addToUFM env tyvar (TyBinder tyvar')
- in
- thing_inside tyvar' mod env' (gus, local_uniq', floats)
\end{code}
Re-numbering types
~~~~~~~~~~~~~~~~~~
\begin{code}
-tidyTy ty mod env usf@(_, local_uniq, _)
- = (nmbr_ty env local_uniq ty, usf)
+tidyTy ty mod in_lam (ty_env, val_env, in_scope) usf@(_, local_uniq, _)
+ = (nmbrType ty_env local_uniq ty, usf)
-- We can use local_uniq as a base for renaming forall'd variables
-- in the type; we don't need to know how many are consumed.
-
--- This little impedance-matcher calls nmbrType with the right arguments
-nmbr_ty env uniq ty
- = nmbrType tv_env uniq ty
- where
- tv_env :: TyVar -> TyVar
- tv_env tyvar = case lookupUFM env tyvar of
- Just (TyBinder tyvar') -> tyvar'
- other -> tyvar
\end{code}
+-- Get rid of this function when we move to the new code generator.
+\begin{code}
+typeOkForCase :: Type -> Bool
+typeOkForCase ty
+ | isUnLiftedType ty -- Primitive case
+ = True
+
+ | otherwise
+ = case (splitAlgTyConApp_maybe ty) of
+ Just (tycon, ty_args, []) -> False
+ Just (tycon, ty_args, non_null_data_cons) | isDataTyCon tycon -> True
+ other -> False
+ -- Null data cons => type is abstract, which code gen can't
+ -- currently handle. (ToDo: when return-in-heap is universal we
+ -- don't need to worry about this.)
+\end{code}
projects / ghc-hetmet.git / blobdiff