3 -- Copyright (c) [2001..2002] Manuel M T Chakravarty & Gabriele Keller
5 -- Vectorisation and lifting
7 --- DESCRIPTION ---------------------------------------------------------------
9 -- This module implements the vectorisation and function lifting
10 -- transformations of the flattening transformation.
12 --- DOCU ----------------------------------------------------------------------
14 -- Language: Haskell 98 with C preprocessor
17 -- the transformation on types has five purposes:
19 -- 1) for each type definition, derive the lifted version of this type
21 -- 2) change the type annotations of functions & variables acc. to rep.
23 -- 3) derive the type of a lifted function
26 -- this is the most fuzzy and complicated part. For each lifted
27 -- sumtype we need to generate function to access and combine the
30 -- NOTE: the type information of variables and data constructors is *not*
31 -- changed to reflect it's representation. This has to be solved
32 -- somehow (???, FIXME) using type indexed types
35 -- is very naive at the moment. One of the most striking inefficiencies is
36 -- application vect (app e1 e2) -> app (fst (vect e1) (vect e2)) if e1 is a
37 -- lambda abstraction. The vectorisation produces a pair consisting of the
38 -- original and the lifted function, but the lifted version is discarded.
39 -- I'm also not sure how much of this would be thrown out by the simplifier
46 --- TODO ----------------------------------------------------------------------
48 -- * look closer into the definition of type definition (TypeThing or so)
55 #include "HsVersions.h"
58 import NDPCoreUtils (tupleTyArgs, funTyArgs, parrElemTy, isDefault,
59 isLit, mkPArrTy, mkTuple, isSimpleExpr, substIdEnv)
60 import FlattenMonad (Flatten, runFlatten, mkBind, extendContext, packContext,
61 liftVar, liftConst, intersectWithContext, mk'fst,
62 mk'lengthP, mk'replicateP, mk'mapP, mk'bpermuteDftP,
63 mk'indexOfP,mk'eq,mk'neq)
66 import StaticFlags (opt_Flatten)
68 import ErrUtils (dumpIfSet_dyn)
69 import UniqSupply (mkSplitUniqSupply)
70 import DynFlags (DynFlag(..))
71 import Literal (Literal, literalType)
72 import Var (Var(..), idType, isTyVar)
74 import DataCon (DataCon, dataConTag)
75 import TypeRep (Type(..))
76 import HscTypes ( ModGuts(..), ModGuts, HscEnv(..), hscEPS )
77 import CoreFVs (exprFreeVars)
78 import CoreSyn (Expr(..), Bind(..), Alt(..), AltCon(..), Note(..),
79 CoreBndr, CoreExpr, CoreBind, mkLams, mkLets,
81 import PprCore (pprCoreExpr)
82 import CoreLint (showPass, endPass)
84 import CoreUtils (exprType, applyTypeToArg, mkPiType)
85 import VarEnv (zipVarEnv)
86 import TysWiredIn (mkTupleTy)
87 import BasicTypes (Boxity(..))
92 -- FIXME: fro debugging - remove this
96 import Monad (liftM, foldM)
98 -- toplevel transformation
99 -- -----------------------
101 -- entry point to the flattening transformation for the compiler driver when
102 -- compiling a complete module (EXPORTED)
107 flatten hsc_env mod_impl@(ModGuts {mg_binds = binds})
108 | not opt_Flatten = return mod_impl -- skip without -fflatten
111 let dflags = hsc_dflags hsc_env
113 eps <- hscEPS hsc_env
114 us <- mkSplitUniqSupply 'l' -- 'l' as in fLattening
116 -- announce vectorisation
118 showPass dflags "Flattening [first phase: vectorisation]"
120 -- vectorise all toplevel bindings
122 let binds' = runFlatten hsc_env eps us $ vectoriseTopLevelBinds binds
124 -- and dump the result if requested
126 endPass dflags "Flattening [first phase: vectorisation]"
127 Opt_D_dump_vect binds'
128 return $ mod_impl {mg_binds = binds'}
130 -- entry point to the flattening transformation for the compiler driver when
131 -- compiling a single expression in interactive mode (EXPORTED)
133 flattenExpr :: HscEnv
134 -> CoreExpr -- the expression to be flattened
136 flattenExpr hsc_env expr
137 | not opt_Flatten = return expr -- skip without -fflatten
140 let dflags = hsc_dflags hsc_env
141 eps <- hscEPS hsc_env
143 us <- mkSplitUniqSupply 'l' -- 'l' as in fLattening
145 -- announce vectorisation
147 showPass dflags "Flattening [first phase: vectorisation]"
149 -- vectorise the expression
151 let expr' = fst . runFlatten hsc_env eps us $ vectorise expr
153 -- and dump the result if requested
155 dumpIfSet_dyn dflags Opt_D_dump_vect "Vectorised expression"
160 -- vectorisation of bindings and expressions
161 -- -----------------------------------------
164 vectoriseTopLevelBinds:: [CoreBind] -> Flatten [CoreBind]
165 vectoriseTopLevelBinds binds =
167 vbinds <- mapM vectoriseBind binds
168 return (adjustTypeBinds vbinds)
170 adjustTypeBinds:: [CoreBind] -> [CoreBind]
171 adjustTypeBinds vbinds =
173 ids = concat (map extIds vbinds)
174 idEnv = zipVarEnv ids ids
175 in map (substIdEnvBind idEnv) vbinds
177 -- FIXME replace by 'bindersOf'
178 extIds (NonRec b expr) = [b]
179 extIds (Rec bnds) = map fst bnds
180 substIdEnvBind idEnv (NonRec b expr) = NonRec b (substIdEnv idEnv expr)
181 substIdEnvBind idEnv (Rec bnds)
182 = Rec (map (\ (b,e) -> (b, (substIdEnv idEnv e))) bnds)
184 -- vectorise a single core binder
186 vectoriseBind :: CoreBind -> Flatten CoreBind
187 vectoriseBind (NonRec b expr) =
188 liftM (NonRec b) $ liftM fst $ vectorise expr
189 vectoriseBind (Rec bindings) =
190 liftM Rec $ mapM vectoriseOne bindings
192 vectoriseOne (b, expr) =
194 (vexpr, ty) <- vectorise expr
195 return (setIdType b ty, vexpr)
198 -- Searches for function definitions and creates a lifted version for
200 -- We have only two interesting cases:
201 -- 1) function application (ex1) (ex2)
202 -- vectorise both subexpressions. The function will end up becoming a
203 -- pair (orig. fun, lifted fun), choose first component (in many cases,
204 -- this is pretty inefficient, since the lifted version is generated
205 -- although it is clear that it won't be used
207 -- 2) lambda abstraction
208 -- any function has to exist in two forms: it's original form and it's
209 -- lifted form. Therefore, every lambda abstraction is transformed into
210 -- a pair of functions: the original function and its lifted variant
213 -- FIXME: currently, I use 'exprType' all over the place - this is terribly
214 -- inefficient. It should be suffiecient to change 'vectorise' and 'lift' to
215 -- return the type of the result expression as well.
217 vectorise:: CoreExpr -> Flatten (CoreExpr, Type)
220 let varTy = idType id
221 let vecTy = vectoriseTy varTy
222 return (Var (setIdType id vecTy), vecTy)
224 vectorise (Lit lit) =
225 return ((Lit lit), literalType lit)
228 vectorise e@(App expr t@(Type _)) =
230 (vexpr, vexprTy) <- vectorise expr
231 return ((App vexpr t), applyTypeToArg vexprTy t)
233 vectorise (App (Lam b expr) arg) =
235 (varg, argTy) <- vectorise arg
236 (vexpr, vexprTy) <- vectorise expr
237 let vb = setIdType b argTy
238 return ((App (Lam vb vexpr) varg),
239 applyTypeToArg (mkPiType vb vexprTy) varg)
241 -- if vexpr expects a type as first argument
242 -- application stays just as it is
244 vectorise (App expr arg) =
246 (vexpr, vexprTy) <- vectorise expr
247 (varg, vargTy) <- vectorise arg
249 if (isPolyType vexprTy)
251 let resTy = applyTypeToArg vexprTy varg
252 return (App vexpr varg, resTy)
254 let [t1, t2] = tupleTyArgs vexprTy
255 vexpr' <- mk'fst t1 t2 vexpr
256 let resTy = applyTypeToArg t1 varg
257 return ((App vexpr' varg), resTy) -- apply the first component of
258 -- the vectorized function
262 (ForAllTy _ _) -> True
263 (NoteTy _ nt) -> isPolyType nt
267 vectorise e@(Lam b expr)
270 (vexpr, vexprTy) <- vectorise expr -- don't vectorise 'b'!
271 return ((Lam b vexpr), mkPiType b vexprTy)
274 (vexpr, vexprTy) <- vectorise expr
275 let vb = setIdType b (vectoriseTy (idType b))
276 let ve = Lam vb vexpr
277 (lexpr, lexprTy) <- lift e
278 let veTy = mkPiType vb vexprTy
279 return $ (mkTuple [veTy, lexprTy] [ve, lexpr],
280 mkTupleTy Boxed 2 [veTy, lexprTy])
282 vectorise (Let bind body) =
284 vbind <- vectoriseBind bind
285 (vbody, vbodyTy) <- vectorise body
286 return ((Let vbind vbody), vbodyTy)
288 vectorise (Case expr b ty alts) =
290 (vexpr, vexprTy) <- vectorise expr
291 valts <- mapM vectorise' alts
292 let res_ty = snd (head valts)
293 return (Case vexpr (setIdType b vexprTy) res_ty (map fst valts), res_ty)
294 where vectorise' (con, bs, expr) =
296 (vexpr, vexprTy) <- vectorise expr
297 return ((con, bs, vexpr), vexprTy) -- FIXME: change type of con
302 vectorise (Note note expr) =
304 (vexpr, vexprTy) <- vectorise expr -- FIXME: is this ok or does it
305 return ((Note note vexpr), vexprTy) -- change the validity of note?
307 vectorise e@(Type t) =
308 return (e, t) -- FIXME: panic instead of 't'???
312 myShowTy (TyVarTy _) = "TyVar "
313 myShowTy (AppTy t1 t2) =
314 "AppTy (" ++ (myShowTy t1) ++ ", " ++ (myShowTy t2) ++ ")"
315 myShowTy (TyConApp _ t) =
316 "TyConApp TC (" ++ (myShowTy t) ++ ")"
319 vectoriseTy :: Type -> Type
320 vectoriseTy t@(TyVarTy v) = t
321 vectoriseTy t@(AppTy t1 t2) =
322 AppTy (vectoriseTy t1) (vectoriseTy t2)
323 vectoriseTy t@(TyConApp tc ts) =
324 TyConApp tc (map vectoriseTy ts)
325 vectoriseTy t@(FunTy t1 t2) =
326 mkTupleTy Boxed 2 [(FunTy (vectoriseTy t1) (vectoriseTy t2)),
328 vectoriseTy t@(ForAllTy v ty) =
329 ForAllTy v (vectoriseTy ty)
330 vectoriseTy t@(NoteTy note ty) = -- FIXME: is the note still valid after
331 NoteTy note (vectoriseTy ty) -- this or should we just throw it away
335 -- liftTy: wrap the type in an array but be careful with function types
336 -- on the *top level* (is this sufficient???)
338 liftTy:: Type -> Type
339 liftTy (FunTy t1 t2) = FunTy (liftTy t1) (liftTy t2)
340 liftTy (ForAllTy tv t) = ForAllTy tv (liftTy t)
341 liftTy (NoteTy n t) = NoteTy n $ liftTy t
342 liftTy t = mkPArrTy t
351 -- liftBinderType: Converts a type 'a' stored in the binder to the
352 -- representation of '[:a:]' will therefore call liftType
354 -- lift type, don't change name (incl unique) nor IdInfo. IdInfo looks ok,
355 -- but I'm not entirely sure about some fields (e.g., strictness info)
356 liftBinderType:: CoreBndr -> Flatten CoreBndr
357 liftBinderType bndr = return $ setIdType bndr (liftTy (idType bndr))
359 -- lift: lifts an expression (a -> [:a:])
360 -- If the expression is a simple expression, it is treated like a constant
362 -- If the body of a lambda expression is a simple expression, it is
363 -- transformed into a mapP
364 lift:: CoreExpr -> Flatten (CoreExpr, Type)
365 lift cExpr@(Var id) =
367 lVar@(Var lId) <- liftVar id
368 return (lVar, idType lId)
370 lift cExpr@(Lit lit) =
372 lLit <- liftConst cExpr
373 return (lLit, exprType lLit)
377 | isSimpleExpr expr = liftSimpleFun b expr
380 (lexpr, lexprTy) <- lift expr -- don't lift b!
381 return (Lam b lexpr, mkPiType b lexprTy)
384 lb <- liftBinderType b
385 (lexpr, lexprTy) <- extendContext [lb] (lift expr)
386 return ((Lam lb lexpr) , mkPiType lb lexprTy)
388 lift (App expr1 expr2) =
390 (lexpr1, lexpr1Ty) <- lift expr1
391 (lexpr2, _) <- lift expr2
392 return ((App lexpr1 lexpr2), applyTypeToArg lexpr1Ty lexpr2)
395 lift (Let (NonRec b expr1) expr2)
396 |isSimpleExpr expr2 =
398 (lexpr1, _) <- lift expr1
399 (lexpr2, lexpr2Ty) <- liftSimpleFun b expr2
400 let (t1, t2) = funTyArgs lexpr2Ty
401 liftM (\x -> (x, liftTy t2)) $ mk'mapP t1 t2 lexpr2 lexpr1
405 (lexpr1, _) <- lift expr1
406 lb <- liftBinderType b
407 (lexpr2, lexpr2Ty) <- extendContext [lb] (lift expr1)
408 return ((Let (NonRec lb lexpr1) lexpr2), lexpr2Ty)
410 lift (Let (Rec binds) expr2) =
412 let (bndVars, exprs) = unzip binds
413 lBndVars <- mapM liftBinderType bndVars
414 lexprs <- extendContext bndVars (mapM lift exprs)
415 (lexpr2, lexpr2Ty) <- extendContext bndVars (lift expr2)
416 return ((Let (Rec (zip lBndVars (map fst lexprs))) lexpr2), lexpr2Ty)
419 -- Assumption: alternatives can either be literals or data construtors.
420 -- Due to type restrictions, I don't think it is possible
421 -- that they are mixed.
422 -- The handling of literals and data constructors is completely
426 -- let b = expr in alts
428 -- I think I read somewhere that the default case (if present) is stored
429 -- in the head of the list. Assume for now this is true, have to check
432 -- (2) data constructors
434 -- FIXME: optimisation: first, filter out all simple expression and
435 -- loop (mapP & filter) over all the corresponding values in a single
438 -- (1) splitAlts:: [Alt CoreBndr] -> ([Alt CoreBndr],[Alt CoreBndr])
439 -- simple alts reg alts
440 -- (2) if simpleAlts = [] then (just as before)
441 -- if regAlts = [] then (the whole thing is just a loop)
442 -- otherwise (a) compute index vector for simpleAlts (for def permute
446 lift cExpr@(Case expr b _ alts) =
448 (lExpr, _) <- lift expr
449 lb <- liftBinderType b -- lift alt-expression
450 lalts <- if isLit alts
451 then extendContext [lb] (liftCaseLit b alts)
452 else extendContext [lb] (liftCaseDataCon b alts)
453 letWrapper lExpr b lalts
455 lift (Note (Coerce t1 t2) expr) =
457 (lexpr, t) <- lift expr
459 return ((Note (Coerce lt1 (liftTy t2)) lexpr), lt1)
461 lift (Note note expr) =
463 (lexpr, t) <- lift expr
464 return ((Note note lexpr), t)
466 lift e@(Type t) = return (e, t)
469 -- auxilliary functions for lifting of case statements
472 liftCaseDataCon:: CoreBndr -> [Alt CoreBndr] ->
473 Flatten (([CoreBind], [CoreBind], [CoreBind]))
474 liftCaseDataCon b [] =
476 liftCaseDataCon b alls@(alt:alts)
479 (i, e, defAltBndrs) <- liftCaseDataConDefault b alt alts
480 (is, es, altBndrs) <- liftCaseDataCon' b alts
481 return (i:is, e:es, defAltBndrs ++ altBndrs)
483 liftCaseDataCon' b alls
485 liftCaseDataCon':: CoreBndr -> [Alt CoreBndr] ->
486 Flatten ([CoreBind], [CoreBind], [CoreBind])
487 liftCaseDataCon' _ [] =
492 liftCaseDataCon' b ((DataAlt dcon, bnds, expr): alts) =
494 (permBnd, exprBnd, packBnd) <- liftSingleDataCon b dcon bnds expr
495 (permBnds, exprBnds, packBnds) <- liftCaseDataCon' b alts
496 return (permBnd:permBnds, exprBnd:exprBnds, packBnd ++ packBnds)
499 -- FIXME: is is really necessary to return the binding to the permutation
500 -- array in the data constructor case, as the representation already
501 -- contains the extended flag vector
502 liftSingleDataCon:: CoreBndr -> DataCon -> [CoreBndr] -> CoreExpr ->
503 Flatten (CoreBind, CoreBind, [CoreBind])
504 liftSingleDataCon b dcon bnds expr =
506 let dconId = dataConTag dcon
507 indexExpr <- mkIndexOfExprDCon (idType b) b dconId
508 (bb, bbind) <- mkBind FSLIT("is") indexExpr
509 lbnds <- mapM liftBinderType bnds
510 ((lExpr, _), bnds') <- packContext bb (extendContext lbnds (lift expr))
511 (_, vbind) <- mkBind FSLIT("r") lExpr
512 return (bbind, vbind, bnds')
514 -- FIXME: clean this up. the datacon and the literal case are so
515 -- similar that it would be easy to use the same function here
516 -- instead of duplicating all the code.
518 liftCaseDataConDefault:: CoreBndr -> (Alt CoreBndr) -> [Alt CoreBndr]
519 -> Flatten (CoreBind, CoreBind, [CoreBind])
520 liftCaseDataConDefault b (_, _, def) alts =
522 let dconIds = map (\(DataAlt d, _, _) -> dataConTag d) alts
523 indexExpr <- mkIndexOfExprDConDft (idType b) b dconIds
524 (bb, bbind) <- mkBind FSLIT("is") indexExpr
525 ((lDef, _), bnds) <- packContext bb (lift def)
526 (_, vbind) <- mkBind FSLIT("r") lDef
527 return (bbind, vbind, bnds)
529 -- liftCaseLit: checks if we have a default case and handles it
531 liftCaseLit:: CoreBndr -> [Alt CoreBndr] ->
532 Flatten ([CoreBind], [CoreBind], [CoreBind])
534 return ([], [], []) --FIXME: a case with no cases at all???
535 liftCaseLit b alls@(alt:alts)
538 (i, e, defAltBndrs) <- liftCaseLitDefault b alt alts
539 (is, es, altBndrs) <- liftCaseLit' b alts
540 return (i:is, e:es, defAltBndrs ++ altBndrs)
545 -- liftCaseLitDefault: looks at all the other alternatives which
546 -- contain a literal and filters all those elements from the
547 -- array which do not match any of the literals in the other
549 liftCaseLitDefault:: CoreBndr -> (Alt CoreBndr) -> [Alt CoreBndr]
550 -> Flatten (CoreBind, CoreBind, [CoreBind])
551 liftCaseLitDefault b (_, _, def) alts =
553 let lits = map (\(LitAlt l, _, _) -> l) alts
554 indexExpr <- mkIndexOfExprDft (idType b) b lits
555 (bb, bbind) <- mkBind FSLIT("is") indexExpr
556 ((lDef, _), bnds) <- packContext bb (lift def)
557 (_, vbind) <- mkBind FSLIT("r") lDef
558 return (bbind, vbind, bnds)
561 -- Assumption: in case of Lit, the list of binders of the alt is empty.
564 -- a list of all vars bound to the expr in the body of the alternative
565 -- a list of (var, expr) pairs, where var has to be bound to expr
567 liftCaseLit':: CoreBndr -> [Alt CoreBndr] ->
568 Flatten ([CoreBind], [CoreBind], [CoreBind])
572 liftCaseLit' b ((LitAlt lit, [], expr):alts) =
574 (permBnd, exprBnd, packBnd) <- liftSingleCaseLit b lit expr
575 (permBnds, exprBnds, packBnds) <- liftCaseLit' b alts
576 return (permBnd:permBnds, exprBnd:exprBnds, packBnd ++ packBnds)
578 -- lift a single alternative of the form: case b of lit -> expr.
580 -- It returns the bindings:
581 -- (a) let b' = indexOfP (mapP (\x -> x == lit) b)
583 -- (b) lift expr in the packed context. Returns lexpr and the
584 -- list of binds (bnds) that describe the packed arrays
586 -- (c) create new var v' to bind lexpr to
588 -- (d) return (b' = indexOf...., v' = lexpr, bnds)
589 liftSingleCaseLit:: CoreBndr -> Literal -> CoreExpr ->
590 Flatten (CoreBind, CoreBind, [CoreBind])
591 liftSingleCaseLit b lit expr =
593 indexExpr <- mkIndexOfExpr (idType b) b lit -- (a)
594 (bb, bbind) <- mkBind FSLIT("is") indexExpr
595 ((lExpr, t), bnds) <- packContext bb (lift expr) -- (b)
596 (_, vbind) <- mkBind FSLIT("r") lExpr
597 return (bbind, vbind, bnds)
599 -- letWrapper lExpr b ([indexbnd_i], [exprbnd_i], [pckbnd_ij])
602 -- let index_bnd_1 in
605 -- let exprbnd_1 in ....
607 -- let nvar = replicate dummy (length <current context>)
608 -- nvar1 = bpermuteDftP index_bnd_1 ...
610 -- in bpermuteDftP index_bnd_n nvar_(n-1)
612 letWrapper:: CoreExpr -> CoreBndr ->([CoreBind], [CoreBind], [CoreBind]) ->
613 Flatten (CoreExpr, Type)
614 letWrapper lExpr b (indBnds, exprBnds, pckBnds) =
616 (defBpBnds, ty) <- dftbpBinders indBnds exprBnds
617 let resExpr = getExprOfBind (head defBpBnds)
618 return ((mkLets (indBnds ++ pckBnds ++ exprBnds ++ defBpBnds) resExpr), ty)
620 -- dftbpBinders: return the list of binders necessary to construct the overall
621 -- result from the subresults computed in the different branches of the case
622 -- statement. The binding which contains the final result is in the *head*
623 -- of the result list.
625 -- dftbpBinders [ind_i = ...] [expr_i = ...] = [dn = ..., d_n-1 = .., d1 = ...]
627 -- let def = replicate (length of context) undefined
628 -- d1 = bpermuteDftP dft e1 i1
631 dftbpBinders:: [CoreBind] -> [CoreBind] -> Flatten ([CoreBind], Type)
632 dftbpBinders indexBnds exprBnds =
634 let expr = getExprOfBind (head exprBnds)
635 defVecExpr <- createDftArrayBind expr
636 ((b, bnds), t) <- dftbpBinders' indexBnds exprBnds defVecExpr
639 dftbpBinders' :: [CoreBind]
642 -> Flatten ((CoreBind, [CoreBind]), Type)
643 dftbpBinders' [] [] cBnd =
644 return ((cBnd, []), panic "dftbpBinders: undefined type")
645 dftbpBinders' (i:is) (e:es) cBind =
647 let iVar = getVarOfBind i
648 let eVar = getVarOfBind e
649 let cVar = getVarOfBind cBind
651 newBnd <- mkDftBackpermute ty iVar eVar cVar
652 ((fBnd, restBnds), _) <- dftbpBinders' is es newBnd
653 return ((fBnd, (newBnd:restBnds)), liftTy ty)
655 dftbpBinders' _ _ _ =
656 panic "Flattening.dftbpBinders: index and expression binder lists have different length!"
658 getExprOfBind:: CoreBind -> CoreExpr
659 getExprOfBind (NonRec _ expr) = expr
661 getVarOfBind:: CoreBind -> Var
662 getVarOfBind (NonRec b _) = b
666 -- Optimised Transformation
667 -- =========================
671 -- if variables x_1 to x_i occur in the context *and* free in expr
673 -- (liftSimpleExpression expr) => mapP (\ (x1,..xn) -> expr) (x1,..xn)
675 liftSimpleFun:: CoreBndr -> CoreExpr -> Flatten (CoreExpr, Type)
676 liftSimpleFun b expr =
678 bndVars <- collectBoundVars expr
679 let bndVars' = b:bndVars
680 bndVarsTuple = mkTuple (map idType bndVars') (map Var bndVars')
681 lamExpr = mkLams (b:bndVars) expr -- FIXME: should be tuple
683 let (t1, t2) = funTyArgs . exprType $ lamExpr
684 mapExpr <- mk'mapP t1 t2 lamExpr bndVarsTuple
685 let lexpr = mkApps mapExpr [bndVarsTuple]
686 return (lexpr, undefined) -- FIXME!!!!!
689 collectBoundVars:: CoreExpr -> Flatten [CoreBndr]
690 collectBoundVars expr =
691 intersectWithContext (exprFreeVars expr)
694 -- auxilliary routines
695 -- -------------------
697 -- mkIndexOfExpr b lit ->
698 -- indexOf (mapP (\x -> x == lit) b) b
700 mkIndexOfExpr:: Type -> CoreBndr -> Literal -> Flatten CoreExpr
701 mkIndexOfExpr idType b lit =
703 eqExpr <- mk'eq idType (Var b) (Lit lit)
704 let lambdaExpr = (Lam b eqExpr)
705 mk'indexOfP idType lambdaExpr (Var b)
707 -- there is FlattenMonad.mk'indexOfP as well as
708 -- CoreSyn.mkApps and CoreSyn.mkLam, all of which should help here
710 -- for case-distinction over data constructors:
714 -- dconId = dataConTag dcon
715 -- the call "mkIndexOfExprDCon b dconId" computes the core expression for
716 -- indexOfP (\x -> x == dconId) b)
718 mkIndexOfExprDCon::Type -> CoreBndr -> Int -> Flatten CoreExpr
719 mkIndexOfExprDCon idType b dId =
721 let intExpr = mkIntLitInt dId
722 eqExpr <- mk'eq idType (Var b) intExpr
723 let lambdaExpr = (Lam b intExpr)
724 mk'indexOfP idType lambdaExpr (Var b)
728 -- there is FlattenMonad.mk'indexOfP as well as
729 -- CoreSyn.mkApps and CoreSyn.mkLam, all of which should help here
731 -- mk'IndexOfExprDConDft b dconIds : Generates the index expression for the
732 -- default case. "dconIds" is a list of all the data constructor idents which
733 -- are covered by the other cases.
734 -- indexOfP (\x -> x != dconId_1 && ....) b)
736 mkIndexOfExprDConDft:: Type -> CoreBndr -> [Int] -> Flatten CoreExpr
737 mkIndexOfExprDConDft idType b dId =
739 let intExprs = map mkIntLitInt dId
740 bExpr <- foldM (mk'neq idType) (head intExprs) (tail intExprs)
741 let lambdaExpr = (Lam b bExpr)
742 mk'indexOfP idType (Var b) bExpr
745 -- mkIndexOfExprDef b [lit1, lit2,...] ->
746 -- indexOf (\x -> not (x == lit1 || x == lit2 ....) b
747 mkIndexOfExprDft:: Type -> CoreBndr -> [Literal] -> Flatten CoreExpr
748 mkIndexOfExprDft idType b lits =
750 let litExprs = map (\l-> Lit l) lits
751 bExpr <- foldM (mk'neq idType) (head litExprs) (tail litExprs)
752 let lambdaExpr = (Lam b bExpr)
753 mk'indexOfP idType bExpr (Var b)
756 -- create a back-permute binder
758 -- * `mkDftBackpermute ty indexArrayVar srcArrayVar dftArrayVar' creates a
759 -- Core binding of the form
761 -- x = bpermuteDftP indexArrayVar srcArrayVar dftArrayVar
763 -- where `x' is a new local variable
765 mkDftBackpermute :: Type -> Var -> Var -> Var -> Flatten CoreBind
766 mkDftBackpermute ty idx src dft =
768 rhs <- mk'bpermuteDftP ty (Var idx) (Var src) (Var dft)
769 liftM snd $ mkBind FSLIT("dbp") rhs
771 -- create a dummy array with elements of the given type, which can be used as
772 -- default array for the combination of the subresults of the lifted case
775 createDftArrayBind :: CoreExpr -> Flatten CoreBind
776 createDftArrayBind e =
777 panic "Flattening.createDftArrayBind: not implemented yet"
780 let ty = parrElemTy . exprType $ expr
782 rhs <- mk'replicateP ty len err??
783 lift snd $ mkBind FSLIT("dft") rhs
784 FIXME: nicht so einfach; man kann kein "error"-Wert nehmen, denn der w"urde
785 beim bpermuteDftP sofort evaluiert, aber es ist auch schwer m"oglich einen
786 generischen Wert f"ur jeden beliebigen Typ zu erfinden.
792 -- show functions (the pretty print functions sometimes don't
793 -- show it the way I want....
795 -- shows just the structure
796 showCoreExpr (Var _ ) = "Var "
797 showCoreExpr (Lit _) = "Lit "
798 showCoreExpr (App e1 e2) =
799 "(App \n " ++ (showCoreExpr e1) ++ "\n " ++ (showCoreExpr e2) ++ ") "
800 showCoreExpr (Lam b e) =
801 "Lam b " ++ (showCoreExpr e)
802 showCoreExpr (Let bnds expr) =
803 "Let \n" ++ (showBinds bnds) ++ "in " ++ (showCoreExpr expr)
804 where showBinds (NonRec b e) = showBind (b,e)
805 showBinds (Rec bnds) = concat (map showBind bnds)
806 showBind (b,e) = " b = " ++ (showCoreExpr e)++ "\n"
808 showCoreExpr (Case ex b ty alts) =
809 "Case b = " ++ (showCoreExpr ex) ++ " of \n" ++ (showAlts alts)
810 where showAlts _ = ""
811 showCoreExpr (Note _ ex) = "Note n " ++ (showCoreExpr ex)
812 showCoreExpr (Type t) = "Type"