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 TcType ( tcIsForAllTy, tcView )
67 import TypeRep ( Type(..) )
68 import StaticFlags (opt_Flatten)
70 import ErrUtils (dumpIfSet_dyn)
71 import UniqSupply (mkSplitUniqSupply)
72 import DynFlags (DynFlag(..))
73 import Literal (Literal, literalType)
74 import Var (Var(..), idType, isTyVar)
76 import DataCon (DataCon, dataConTag)
77 import HscTypes ( ModGuts(..), ModGuts, HscEnv(..), hscEPS )
78 import CoreFVs (exprFreeVars)
79 import CoreSyn (Expr(..), Bind(..), Alt(..), AltCon(..), Note(..),
80 CoreBndr, CoreExpr, CoreBind, mkLams, mkLets,
82 import PprCore (pprCoreExpr)
83 import CoreLint (showPass, endPass)
85 import CoreUtils (exprType, applyTypeToArg, mkPiType)
86 import VarEnv (zipVarEnv)
87 import TysWiredIn (mkTupleTy)
88 import BasicTypes (Boxity(..))
93 -- FIXME: fro debugging - remove this
97 import Monad (liftM, foldM)
99 -- toplevel transformation
100 -- -----------------------
102 -- entry point to the flattening transformation for the compiler driver when
103 -- compiling a complete module (EXPORTED)
108 flatten hsc_env mod_impl@(ModGuts {mg_binds = binds})
109 | not opt_Flatten = return mod_impl -- skip without -fflatten
112 let dflags = hsc_dflags hsc_env
114 eps <- hscEPS hsc_env
115 us <- mkSplitUniqSupply 'l' -- 'l' as in fLattening
117 -- announce vectorisation
119 showPass dflags "Flattening [first phase: vectorisation]"
121 -- vectorise all toplevel bindings
123 let binds' = runFlatten hsc_env eps us $ vectoriseTopLevelBinds binds
125 -- and dump the result if requested
127 endPass dflags "Flattening [first phase: vectorisation]"
128 Opt_D_dump_vect binds'
129 return $ mod_impl {mg_binds = binds'}
131 -- entry point to the flattening transformation for the compiler driver when
132 -- compiling a single expression in interactive mode (EXPORTED)
134 flattenExpr :: HscEnv
135 -> CoreExpr -- the expression to be flattened
137 flattenExpr hsc_env expr
138 | not opt_Flatten = return expr -- skip without -fflatten
141 let dflags = hsc_dflags hsc_env
142 eps <- hscEPS hsc_env
144 us <- mkSplitUniqSupply 'l' -- 'l' as in fLattening
146 -- announce vectorisation
148 showPass dflags "Flattening [first phase: vectorisation]"
150 -- vectorise the expression
152 let expr' = fst . runFlatten hsc_env eps us $ vectorise expr
154 -- and dump the result if requested
156 dumpIfSet_dyn dflags Opt_D_dump_vect "Vectorised expression"
161 -- vectorisation of bindings and expressions
162 -- -----------------------------------------
165 vectoriseTopLevelBinds:: [CoreBind] -> Flatten [CoreBind]
166 vectoriseTopLevelBinds binds =
168 vbinds <- mapM vectoriseBind binds
169 return (adjustTypeBinds vbinds)
171 adjustTypeBinds:: [CoreBind] -> [CoreBind]
172 adjustTypeBinds vbinds =
174 ids = concat (map extIds vbinds)
175 idEnv = zipVarEnv ids ids
176 in map (substIdEnvBind idEnv) vbinds
178 -- FIXME replace by 'bindersOf'
179 extIds (NonRec b expr) = [b]
180 extIds (Rec bnds) = map fst bnds
181 substIdEnvBind idEnv (NonRec b expr) = NonRec b (substIdEnv idEnv expr)
182 substIdEnvBind idEnv (Rec bnds)
183 = Rec (map (\ (b,e) -> (b, (substIdEnv idEnv e))) bnds)
185 -- vectorise a single core binder
187 vectoriseBind :: CoreBind -> Flatten CoreBind
188 vectoriseBind (NonRec b expr) =
189 liftM (NonRec b) $ liftM fst $ vectorise expr
190 vectoriseBind (Rec bindings) =
191 liftM Rec $ mapM vectoriseOne bindings
193 vectoriseOne (b, expr) =
195 (vexpr, ty) <- vectorise expr
196 return (setIdType b ty, vexpr)
199 -- Searches for function definitions and creates a lifted version for
201 -- We have only two interesting cases:
202 -- 1) function application (ex1) (ex2)
203 -- vectorise both subexpressions. The function will end up becoming a
204 -- pair (orig. fun, lifted fun), choose first component (in many cases,
205 -- this is pretty inefficient, since the lifted version is generated
206 -- although it is clear that it won't be used
208 -- 2) lambda abstraction
209 -- any function has to exist in two forms: it's original form and it's
210 -- lifted form. Therefore, every lambda abstraction is transformed into
211 -- a pair of functions: the original function and its lifted variant
214 -- FIXME: currently, I use 'exprType' all over the place - this is terribly
215 -- inefficient. It should be suffiecient to change 'vectorise' and 'lift' to
216 -- return the type of the result expression as well.
218 vectorise:: CoreExpr -> Flatten (CoreExpr, Type)
221 let varTy = idType id
222 let vecTy = vectoriseTy varTy
223 return (Var (setIdType id vecTy), vecTy)
225 vectorise (Lit lit) =
226 return ((Lit lit), literalType lit)
229 vectorise e@(App expr t@(Type _)) =
231 (vexpr, vexprTy) <- vectorise expr
232 return ((App vexpr t), applyTypeToArg vexprTy t)
234 vectorise (App (Lam b expr) arg) =
236 (varg, argTy) <- vectorise arg
237 (vexpr, vexprTy) <- vectorise expr
238 let vb = setIdType b argTy
239 return ((App (Lam vb vexpr) varg),
240 applyTypeToArg (mkPiType vb vexprTy) varg)
242 -- if vexpr expects a type as first argument
243 -- application stays just as it is
245 vectorise (App expr arg) =
247 (vexpr, vexprTy) <- vectorise expr
248 (varg, vargTy) <- vectorise arg
250 if (tcIsForAllTy vexprTy)
252 let resTy = applyTypeToArg vexprTy varg
253 return (App vexpr varg, resTy)
255 let [t1, t2] = tupleTyArgs vexprTy
256 vexpr' <- mk'fst t1 t2 vexpr
257 let resTy = applyTypeToArg t1 varg
258 return ((App vexpr' varg), resTy) -- apply the first component of
259 -- the vectorized function
261 vectorise e@(Lam b expr)
264 (vexpr, vexprTy) <- vectorise expr -- don't vectorise 'b'!
265 return ((Lam b vexpr), mkPiType b vexprTy)
268 (vexpr, vexprTy) <- vectorise expr
269 let vb = setIdType b (vectoriseTy (idType b))
270 let ve = Lam vb vexpr
271 (lexpr, lexprTy) <- lift e
272 let veTy = mkPiType vb vexprTy
273 return $ (mkTuple [veTy, lexprTy] [ve, lexpr],
274 mkTupleTy Boxed 2 [veTy, lexprTy])
276 vectorise (Let bind body) =
278 vbind <- vectoriseBind bind
279 (vbody, vbodyTy) <- vectorise body
280 return ((Let vbind vbody), vbodyTy)
282 vectorise (Case expr b ty alts) =
284 (vexpr, vexprTy) <- vectorise expr
285 valts <- mapM vectorise' alts
286 let res_ty = snd (head valts)
287 return (Case vexpr (setIdType b vexprTy) res_ty (map fst valts), res_ty)
288 where vectorise' (con, bs, expr) =
290 (vexpr, vexprTy) <- vectorise expr
291 return ((con, bs, vexpr), vexprTy) -- FIXME: change type of con
296 vectorise (Note note expr) =
298 (vexpr, vexprTy) <- vectorise expr -- FIXME: is this ok or does it
299 return ((Note note vexpr), vexprTy) -- change the validity of note?
301 vectorise e@(Type t) =
302 return (e, t) -- FIXME: panic instead of 't'???
306 myShowTy (TyVarTy _) = "TyVar "
307 myShowTy (AppTy t1 t2) =
308 "AppTy (" ++ (myShowTy t1) ++ ", " ++ (myShowTy t2) ++ ")"
309 myShowTy (TyConApp _ t) =
310 "TyConApp TC (" ++ (myShowTy t) ++ ")"
313 vectoriseTy :: Type -> Type
314 vectoriseTy ty | Just ty' <- tcView ty = vectoriseTy ty'
315 -- Look through notes and synonyms
316 -- NB: This will discard notes and synonyms, of course
317 -- ToDo: retain somehow?
318 vectoriseTy t@(TyVarTy v) = t
319 vectoriseTy t@(AppTy t1 t2) =
320 AppTy (vectoriseTy t1) (vectoriseTy t2)
321 vectoriseTy t@(TyConApp tc ts) =
322 TyConApp tc (map vectoriseTy ts)
323 vectoriseTy t@(FunTy t1 t2) =
324 mkTupleTy Boxed 2 [(FunTy (vectoriseTy t1) (vectoriseTy t2)),
326 vectoriseTy t@(ForAllTy v ty) =
327 ForAllTy v (vectoriseTy ty)
331 -- liftTy: wrap the type in an array but be careful with function types
332 -- on the *top level* (is this sufficient???)
334 liftTy:: Type -> Type
335 liftTy ty | Just ty' <- tcView ty = liftTy ty'
336 liftTy (FunTy t1 t2) = FunTy (liftTy t1) (liftTy t2)
337 liftTy (ForAllTy tv t) = ForAllTy tv (liftTy t)
338 liftTy t = mkPArrTy t
347 -- liftBinderType: Converts a type 'a' stored in the binder to the
348 -- representation of '[:a:]' will therefore call liftType
350 -- lift type, don't change name (incl unique) nor IdInfo. IdInfo looks ok,
351 -- but I'm not entirely sure about some fields (e.g., strictness info)
352 liftBinderType:: CoreBndr -> Flatten CoreBndr
353 liftBinderType bndr = return $ setIdType bndr (liftTy (idType bndr))
355 -- lift: lifts an expression (a -> [:a:])
356 -- If the expression is a simple expression, it is treated like a constant
358 -- If the body of a lambda expression is a simple expression, it is
359 -- transformed into a mapP
360 lift:: CoreExpr -> Flatten (CoreExpr, Type)
361 lift cExpr@(Var id) =
363 lVar@(Var lId) <- liftVar id
364 return (lVar, idType lId)
366 lift cExpr@(Lit lit) =
368 lLit <- liftConst cExpr
369 return (lLit, exprType lLit)
373 | isSimpleExpr expr = liftSimpleFun b expr
376 (lexpr, lexprTy) <- lift expr -- don't lift b!
377 return (Lam b lexpr, mkPiType b lexprTy)
380 lb <- liftBinderType b
381 (lexpr, lexprTy) <- extendContext [lb] (lift expr)
382 return ((Lam lb lexpr) , mkPiType lb lexprTy)
384 lift (App expr1 expr2) =
386 (lexpr1, lexpr1Ty) <- lift expr1
387 (lexpr2, _) <- lift expr2
388 return ((App lexpr1 lexpr2), applyTypeToArg lexpr1Ty lexpr2)
391 lift (Let (NonRec b expr1) expr2)
392 |isSimpleExpr expr2 =
394 (lexpr1, _) <- lift expr1
395 (lexpr2, lexpr2Ty) <- liftSimpleFun b expr2
396 let (t1, t2) = funTyArgs lexpr2Ty
397 liftM (\x -> (x, liftTy t2)) $ mk'mapP t1 t2 lexpr2 lexpr1
401 (lexpr1, _) <- lift expr1
402 lb <- liftBinderType b
403 (lexpr2, lexpr2Ty) <- extendContext [lb] (lift expr1)
404 return ((Let (NonRec lb lexpr1) lexpr2), lexpr2Ty)
406 lift (Let (Rec binds) expr2) =
408 let (bndVars, exprs) = unzip binds
409 lBndVars <- mapM liftBinderType bndVars
410 lexprs <- extendContext bndVars (mapM lift exprs)
411 (lexpr2, lexpr2Ty) <- extendContext bndVars (lift expr2)
412 return ((Let (Rec (zip lBndVars (map fst lexprs))) lexpr2), lexpr2Ty)
415 -- Assumption: alternatives can either be literals or data construtors.
416 -- Due to type restrictions, I don't think it is possible
417 -- that they are mixed.
418 -- The handling of literals and data constructors is completely
422 -- let b = expr in alts
424 -- I think I read somewhere that the default case (if present) is stored
425 -- in the head of the list. Assume for now this is true, have to check
428 -- (2) data constructors
430 -- FIXME: optimisation: first, filter out all simple expression and
431 -- loop (mapP & filter) over all the corresponding values in a single
434 -- (1) splitAlts:: [Alt CoreBndr] -> ([Alt CoreBndr],[Alt CoreBndr])
435 -- simple alts reg alts
436 -- (2) if simpleAlts = [] then (just as before)
437 -- if regAlts = [] then (the whole thing is just a loop)
438 -- otherwise (a) compute index vector for simpleAlts (for def permute
442 lift cExpr@(Case expr b _ alts) =
444 (lExpr, _) <- lift expr
445 lb <- liftBinderType b -- lift alt-expression
446 lalts <- if isLit alts
447 then extendContext [lb] (liftCaseLit b alts)
448 else extendContext [lb] (liftCaseDataCon b alts)
449 letWrapper lExpr b lalts
451 lift (Note (Coerce t1 t2) expr) =
453 (lexpr, t) <- lift expr
455 return ((Note (Coerce lt1 (liftTy t2)) lexpr), lt1)
457 lift (Note note expr) =
459 (lexpr, t) <- lift expr
460 return ((Note note lexpr), t)
462 lift e@(Type t) = return (e, t)
465 -- auxilliary functions for lifting of case statements
468 liftCaseDataCon:: CoreBndr -> [Alt CoreBndr] ->
469 Flatten (([CoreBind], [CoreBind], [CoreBind]))
470 liftCaseDataCon b [] =
472 liftCaseDataCon b alls@(alt:alts)
475 (i, e, defAltBndrs) <- liftCaseDataConDefault b alt alts
476 (is, es, altBndrs) <- liftCaseDataCon' b alts
477 return (i:is, e:es, defAltBndrs ++ altBndrs)
479 liftCaseDataCon' b alls
481 liftCaseDataCon':: CoreBndr -> [Alt CoreBndr] ->
482 Flatten ([CoreBind], [CoreBind], [CoreBind])
483 liftCaseDataCon' _ [] =
488 liftCaseDataCon' b ((DataAlt dcon, bnds, expr): alts) =
490 (permBnd, exprBnd, packBnd) <- liftSingleDataCon b dcon bnds expr
491 (permBnds, exprBnds, packBnds) <- liftCaseDataCon' b alts
492 return (permBnd:permBnds, exprBnd:exprBnds, packBnd ++ packBnds)
495 -- FIXME: is is really necessary to return the binding to the permutation
496 -- array in the data constructor case, as the representation already
497 -- contains the extended flag vector
498 liftSingleDataCon:: CoreBndr -> DataCon -> [CoreBndr] -> CoreExpr ->
499 Flatten (CoreBind, CoreBind, [CoreBind])
500 liftSingleDataCon b dcon bnds expr =
502 let dconId = dataConTag dcon
503 indexExpr <- mkIndexOfExprDCon (idType b) b dconId
504 (bb, bbind) <- mkBind FSLIT("is") indexExpr
505 lbnds <- mapM liftBinderType bnds
506 ((lExpr, _), bnds') <- packContext bb (extendContext lbnds (lift expr))
507 (_, vbind) <- mkBind FSLIT("r") lExpr
508 return (bbind, vbind, bnds')
510 -- FIXME: clean this up. the datacon and the literal case are so
511 -- similar that it would be easy to use the same function here
512 -- instead of duplicating all the code.
514 liftCaseDataConDefault:: CoreBndr -> (Alt CoreBndr) -> [Alt CoreBndr]
515 -> Flatten (CoreBind, CoreBind, [CoreBind])
516 liftCaseDataConDefault b (_, _, def) alts =
518 let dconIds = map (\(DataAlt d, _, _) -> dataConTag d) alts
519 indexExpr <- mkIndexOfExprDConDft (idType b) b dconIds
520 (bb, bbind) <- mkBind FSLIT("is") indexExpr
521 ((lDef, _), bnds) <- packContext bb (lift def)
522 (_, vbind) <- mkBind FSLIT("r") lDef
523 return (bbind, vbind, bnds)
525 -- liftCaseLit: checks if we have a default case and handles it
527 liftCaseLit:: CoreBndr -> [Alt CoreBndr] ->
528 Flatten ([CoreBind], [CoreBind], [CoreBind])
530 return ([], [], []) --FIXME: a case with no cases at all???
531 liftCaseLit b alls@(alt:alts)
534 (i, e, defAltBndrs) <- liftCaseLitDefault b alt alts
535 (is, es, altBndrs) <- liftCaseLit' b alts
536 return (i:is, e:es, defAltBndrs ++ altBndrs)
541 -- liftCaseLitDefault: looks at all the other alternatives which
542 -- contain a literal and filters all those elements from the
543 -- array which do not match any of the literals in the other
545 liftCaseLitDefault:: CoreBndr -> (Alt CoreBndr) -> [Alt CoreBndr]
546 -> Flatten (CoreBind, CoreBind, [CoreBind])
547 liftCaseLitDefault b (_, _, def) alts =
549 let lits = map (\(LitAlt l, _, _) -> l) alts
550 indexExpr <- mkIndexOfExprDft (idType b) b lits
551 (bb, bbind) <- mkBind FSLIT("is") indexExpr
552 ((lDef, _), bnds) <- packContext bb (lift def)
553 (_, vbind) <- mkBind FSLIT("r") lDef
554 return (bbind, vbind, bnds)
557 -- Assumption: in case of Lit, the list of binders of the alt is empty.
560 -- a list of all vars bound to the expr in the body of the alternative
561 -- a list of (var, expr) pairs, where var has to be bound to expr
563 liftCaseLit':: CoreBndr -> [Alt CoreBndr] ->
564 Flatten ([CoreBind], [CoreBind], [CoreBind])
568 liftCaseLit' b ((LitAlt lit, [], expr):alts) =
570 (permBnd, exprBnd, packBnd) <- liftSingleCaseLit b lit expr
571 (permBnds, exprBnds, packBnds) <- liftCaseLit' b alts
572 return (permBnd:permBnds, exprBnd:exprBnds, packBnd ++ packBnds)
574 -- lift a single alternative of the form: case b of lit -> expr.
576 -- It returns the bindings:
577 -- (a) let b' = indexOfP (mapP (\x -> x == lit) b)
579 -- (b) lift expr in the packed context. Returns lexpr and the
580 -- list of binds (bnds) that describe the packed arrays
582 -- (c) create new var v' to bind lexpr to
584 -- (d) return (b' = indexOf...., v' = lexpr, bnds)
585 liftSingleCaseLit:: CoreBndr -> Literal -> CoreExpr ->
586 Flatten (CoreBind, CoreBind, [CoreBind])
587 liftSingleCaseLit b lit expr =
589 indexExpr <- mkIndexOfExpr (idType b) b lit -- (a)
590 (bb, bbind) <- mkBind FSLIT("is") indexExpr
591 ((lExpr, t), bnds) <- packContext bb (lift expr) -- (b)
592 (_, vbind) <- mkBind FSLIT("r") lExpr
593 return (bbind, vbind, bnds)
595 -- letWrapper lExpr b ([indexbnd_i], [exprbnd_i], [pckbnd_ij])
598 -- let index_bnd_1 in
601 -- let exprbnd_1 in ....
603 -- let nvar = replicate dummy (length <current context>)
604 -- nvar1 = bpermuteDftP index_bnd_1 ...
606 -- in bpermuteDftP index_bnd_n nvar_(n-1)
608 letWrapper:: CoreExpr -> CoreBndr ->([CoreBind], [CoreBind], [CoreBind]) ->
609 Flatten (CoreExpr, Type)
610 letWrapper lExpr b (indBnds, exprBnds, pckBnds) =
612 (defBpBnds, ty) <- dftbpBinders indBnds exprBnds
613 let resExpr = getExprOfBind (head defBpBnds)
614 return ((mkLets (indBnds ++ pckBnds ++ exprBnds ++ defBpBnds) resExpr), ty)
616 -- dftbpBinders: return the list of binders necessary to construct the overall
617 -- result from the subresults computed in the different branches of the case
618 -- statement. The binding which contains the final result is in the *head*
619 -- of the result list.
621 -- dftbpBinders [ind_i = ...] [expr_i = ...] = [dn = ..., d_n-1 = .., d1 = ...]
623 -- let def = replicate (length of context) undefined
624 -- d1 = bpermuteDftP dft e1 i1
627 dftbpBinders:: [CoreBind] -> [CoreBind] -> Flatten ([CoreBind], Type)
628 dftbpBinders indexBnds exprBnds =
630 let expr = getExprOfBind (head exprBnds)
631 defVecExpr <- createDftArrayBind expr
632 ((b, bnds), t) <- dftbpBinders' indexBnds exprBnds defVecExpr
635 dftbpBinders' :: [CoreBind]
638 -> Flatten ((CoreBind, [CoreBind]), Type)
639 dftbpBinders' [] [] cBnd =
640 return ((cBnd, []), panic "dftbpBinders: undefined type")
641 dftbpBinders' (i:is) (e:es) cBind =
643 let iVar = getVarOfBind i
644 let eVar = getVarOfBind e
645 let cVar = getVarOfBind cBind
647 newBnd <- mkDftBackpermute ty iVar eVar cVar
648 ((fBnd, restBnds), _) <- dftbpBinders' is es newBnd
649 return ((fBnd, (newBnd:restBnds)), liftTy ty)
651 dftbpBinders' _ _ _ =
652 panic "Flattening.dftbpBinders: index and expression binder lists have different length!"
654 getExprOfBind:: CoreBind -> CoreExpr
655 getExprOfBind (NonRec _ expr) = expr
657 getVarOfBind:: CoreBind -> Var
658 getVarOfBind (NonRec b _) = b
662 -- Optimised Transformation
663 -- =========================
667 -- if variables x_1 to x_i occur in the context *and* free in expr
669 -- (liftSimpleExpression expr) => mapP (\ (x1,..xn) -> expr) (x1,..xn)
671 liftSimpleFun:: CoreBndr -> CoreExpr -> Flatten (CoreExpr, Type)
672 liftSimpleFun b expr =
674 bndVars <- collectBoundVars expr
675 let bndVars' = b:bndVars
676 bndVarsTuple = mkTuple (map idType bndVars') (map Var bndVars')
677 lamExpr = mkLams (b:bndVars) expr -- FIXME: should be tuple
679 let (t1, t2) = funTyArgs . exprType $ lamExpr
680 mapExpr <- mk'mapP t1 t2 lamExpr bndVarsTuple
681 let lexpr = mkApps mapExpr [bndVarsTuple]
682 return (lexpr, undefined) -- FIXME!!!!!
685 collectBoundVars:: CoreExpr -> Flatten [CoreBndr]
686 collectBoundVars expr =
687 intersectWithContext (exprFreeVars expr)
690 -- auxilliary routines
691 -- -------------------
693 -- mkIndexOfExpr b lit ->
694 -- indexOf (mapP (\x -> x == lit) b) b
696 mkIndexOfExpr:: Type -> CoreBndr -> Literal -> Flatten CoreExpr
697 mkIndexOfExpr idType b lit =
699 eqExpr <- mk'eq idType (Var b) (Lit lit)
700 let lambdaExpr = (Lam b eqExpr)
701 mk'indexOfP idType lambdaExpr (Var b)
703 -- there is FlattenMonad.mk'indexOfP as well as
704 -- CoreSyn.mkApps and CoreSyn.mkLam, all of which should help here
706 -- for case-distinction over data constructors:
710 -- dconId = dataConTag dcon
711 -- the call "mkIndexOfExprDCon b dconId" computes the core expression for
712 -- indexOfP (\x -> x == dconId) b)
714 mkIndexOfExprDCon::Type -> CoreBndr -> Int -> Flatten CoreExpr
715 mkIndexOfExprDCon idType b dId =
717 let intExpr = mkIntLitInt dId
718 eqExpr <- mk'eq idType (Var b) intExpr
719 let lambdaExpr = (Lam b intExpr)
720 mk'indexOfP idType lambdaExpr (Var b)
724 -- there is FlattenMonad.mk'indexOfP as well as
725 -- CoreSyn.mkApps and CoreSyn.mkLam, all of which should help here
727 -- mk'IndexOfExprDConDft b dconIds : Generates the index expression for the
728 -- default case. "dconIds" is a list of all the data constructor idents which
729 -- are covered by the other cases.
730 -- indexOfP (\x -> x != dconId_1 && ....) b)
732 mkIndexOfExprDConDft:: Type -> CoreBndr -> [Int] -> Flatten CoreExpr
733 mkIndexOfExprDConDft idType b dId =
735 let intExprs = map mkIntLitInt dId
736 bExpr <- foldM (mk'neq idType) (head intExprs) (tail intExprs)
737 let lambdaExpr = (Lam b bExpr)
738 mk'indexOfP idType (Var b) bExpr
741 -- mkIndexOfExprDef b [lit1, lit2,...] ->
742 -- indexOf (\x -> not (x == lit1 || x == lit2 ....) b
743 mkIndexOfExprDft:: Type -> CoreBndr -> [Literal] -> Flatten CoreExpr
744 mkIndexOfExprDft idType b lits =
746 let litExprs = map (\l-> Lit l) lits
747 bExpr <- foldM (mk'neq idType) (head litExprs) (tail litExprs)
748 let lambdaExpr = (Lam b bExpr)
749 mk'indexOfP idType bExpr (Var b)
752 -- create a back-permute binder
754 -- * `mkDftBackpermute ty indexArrayVar srcArrayVar dftArrayVar' creates a
755 -- Core binding of the form
757 -- x = bpermuteDftP indexArrayVar srcArrayVar dftArrayVar
759 -- where `x' is a new local variable
761 mkDftBackpermute :: Type -> Var -> Var -> Var -> Flatten CoreBind
762 mkDftBackpermute ty idx src dft =
764 rhs <- mk'bpermuteDftP ty (Var idx) (Var src) (Var dft)
765 liftM snd $ mkBind FSLIT("dbp") rhs
767 -- create a dummy array with elements of the given type, which can be used as
768 -- default array for the combination of the subresults of the lifted case
771 createDftArrayBind :: CoreExpr -> Flatten CoreBind
772 createDftArrayBind e =
773 panic "Flattening.createDftArrayBind: not implemented yet"
776 let ty = parrElemTy . exprType $ expr
778 rhs <- mk'replicateP ty len err??
779 lift snd $ mkBind FSLIT("dft") rhs
780 FIXME: nicht so einfach; man kann kein "error"-Wert nehmen, denn der w"urde
781 beim bpermuteDftP sofort evaluiert, aber es ist auch schwer m"oglich einen
782 generischen Wert f"ur jeden beliebigen Typ zu erfinden.
788 -- show functions (the pretty print functions sometimes don't
789 -- show it the way I want....
791 -- shows just the structure
792 showCoreExpr (Var _ ) = "Var "
793 showCoreExpr (Lit _) = "Lit "
794 showCoreExpr (App e1 e2) =
795 "(App \n " ++ (showCoreExpr e1) ++ "\n " ++ (showCoreExpr e2) ++ ") "
796 showCoreExpr (Lam b e) =
797 "Lam b " ++ (showCoreExpr e)
798 showCoreExpr (Let bnds expr) =
799 "Let \n" ++ (showBinds bnds) ++ "in " ++ (showCoreExpr expr)
800 where showBinds (NonRec b e) = showBind (b,e)
801 showBinds (Rec bnds) = concat (map showBind bnds)
802 showBind (b,e) = " b = " ++ (showCoreExpr e)++ "\n"
804 showCoreExpr (Case ex b ty alts) =
805 "Case b = " ++ (showCoreExpr ex) ++ " of \n" ++ (showAlts alts)
806 where showAlts _ = ""
807 showCoreExpr (Note _ ex) = "Note n " ++ (showCoreExpr ex)
808 showCoreExpr (Type t) = "Type"