1 {-# LANGUAGE PackageImports #-}
3 -- Functions to bring a Core expression in normal form. This module provides a
4 -- top level function "normalize", and defines the actual transformation passes that
7 module CLasH.Normalize (getNormalized, normalizeExpr, splitNormalized) where
11 import qualified Maybe
13 import qualified "transformers" Control.Monad.Trans as Trans
14 import qualified Control.Monad as Monad
15 import qualified Control.Monad.Trans.Writer as Writer
16 import qualified Data.Map as Map
17 import qualified Data.Monoid as Monoid
22 import qualified UniqSupply
23 import qualified CoreUtils
25 import qualified TcType
28 import qualified VarSet
29 import qualified NameSet
30 import qualified CoreFVs
31 import qualified CoreUtils
32 import qualified MkCore
33 import qualified HscTypes
34 import Outputable ( showSDoc, ppr, nest )
37 import CLasH.Normalize.NormalizeTypes
38 import CLasH.Translator.TranslatorTypes
39 import CLasH.Normalize.NormalizeTools
40 import CLasH.VHDL.VHDLTypes
41 import qualified CLasH.Utils as Utils
42 import CLasH.Utils.Core.CoreTools
43 import CLasH.Utils.Core.BinderTools
44 import CLasH.Utils.Pretty
46 --------------------------------
47 -- Start of transformations
48 --------------------------------
50 --------------------------------
52 --------------------------------
53 eta, etatop :: Transform
54 eta expr | is_fun expr && not (is_lam expr) = do
55 let arg_ty = (fst . Type.splitFunTy . CoreUtils.exprType) expr
56 id <- Trans.lift $ mkInternalVar "param" arg_ty
57 change (Lam id (App expr (Var id)))
58 -- Leave all other expressions unchanged
60 etatop = notappargs ("eta", eta)
62 --------------------------------
64 --------------------------------
65 beta, betatop :: Transform
66 -- Substitute arg for x in expr
67 beta (App (Lam x expr) arg) = change $ substitute [(x, arg)] expr
68 -- Propagate the application into the let
69 beta (App (Let binds expr) arg) = change $ Let binds (App expr arg)
70 -- Propagate the application into each of the alternatives
71 beta (App (Case scrut b ty alts) arg) = change $ Case scrut b ty' alts'
73 alts' = map (\(con, bndrs, expr) -> (con, bndrs, (App expr arg))) alts
74 ty' = CoreUtils.applyTypeToArg ty arg
75 -- Leave all other expressions unchanged
76 beta expr = return expr
77 -- Perform this transform everywhere
78 betatop = everywhere ("beta", beta)
80 --------------------------------
82 --------------------------------
83 -- Try to move casts as much downward as possible.
84 castprop, castproptop :: Transform
85 castprop (Cast (Let binds expr) ty) = change $ Let binds (Cast expr ty)
86 castprop expr@(Cast (Case scrut b _ alts) ty) = change (Case scrut b ty alts')
88 alts' = map (\(con, bndrs, expr) -> (con, bndrs, (Cast expr ty))) alts
89 -- Leave all other expressions unchanged
90 castprop expr = return expr
91 -- Perform this transform everywhere
92 castproptop = everywhere ("castprop", castprop)
94 --------------------------------
95 -- Cast simplification. Mostly useful for state packing and unpacking, but
96 -- perhaps for others as well.
97 --------------------------------
98 castsimpl, castsimpltop :: Transform
99 castsimpl expr@(Cast val ty) = do
100 -- Don't extract values that are already simpl
101 local_var <- Trans.lift $ is_local_var val
102 -- Don't extract values that are not representable, to prevent loops with
105 if (not local_var) && repr
107 -- Generate a binder for the expression
108 id <- Trans.lift $ mkBinderFor val "castval"
109 -- Extract the expression
110 change $ Let (NonRec id val) (Cast (Var id) ty)
113 -- Leave all other expressions unchanged
114 castsimpl expr = return expr
115 -- Perform this transform everywhere
116 castsimpltop = everywhere ("castsimpl", castsimpl)
119 --------------------------------
120 -- Lambda simplication
121 --------------------------------
122 -- Ensure that a lambda always evaluates to a let expressions or a simple
123 -- variable reference.
124 lambdasimpl, lambdasimpltop :: Transform
125 -- Don't simplify a lambda that evaluates to let, since this is already
126 -- normal form (and would cause infinite loops).
127 lambdasimpl expr@(Lam _ (Let _ _)) = return expr
128 -- Put the of a lambda in its own binding, but not when the expression is
129 -- already a local variable, or not representable (to prevent loops with
131 lambdasimpl expr@(Lam bndr res) = do
133 local_var <- Trans.lift $ is_local_var res
134 if not local_var && repr
136 id <- Trans.lift $ mkBinderFor res "res"
137 change $ Lam bndr (Let (NonRec id res) (Var id))
139 -- If the result is already a local var or not representable, don't
143 -- Leave all other expressions unchanged
144 lambdasimpl expr = return expr
145 -- Perform this transform everywhere
146 lambdasimpltop = everywhere ("lambdasimpl", lambdasimpl)
148 --------------------------------
149 -- let derecursification
150 --------------------------------
151 letderec, letderectop :: Transform
152 letderec expr@(Let (Rec binds) res) = case liftable of
153 -- Nothing is liftable, just return
155 -- Something can be lifted, generate a new let expression
156 _ -> change $ mkNonRecLets liftable (Let (Rec nonliftable) res)
158 -- Make a list of all the binders bound in this recursive let
159 bndrs = map fst binds
160 -- See which bindings are liftable
161 (liftable, nonliftable) = List.partition canlift binds
162 -- Any expression that does not use any of the binders in this recursive let
163 -- can be lifted into a nonrec let. It can't use its own binder either,
164 -- since that would mean the binding is self-recursive and should be in a
165 -- single bind recursive let.
166 canlift (bndr, e) = not $ expr_uses_binders bndrs e
167 -- Leave all other expressions unchanged
168 letderec expr = return expr
169 -- Perform this transform everywhere
170 letderectop = everywhere ("letderec", letderec)
172 --------------------------------
173 -- let simplification
174 --------------------------------
175 letsimpl, letsimpltop :: Transform
176 -- Don't simplify a let that evaluates to another let, since this is already
177 -- normal form (and would cause infinite loops with letflat below).
178 letsimpl expr@(Let _ (Let _ _)) = return expr
179 -- Put the "in ..." value of a let in its own binding, but not when the
180 -- expression is already a local variable, or not representable (to prevent loops with inlinenonrep).
181 letsimpl expr@(Let binds res) = do
183 local_var <- Trans.lift $ is_local_var res
184 if not local_var && repr
186 -- If the result is not a local var already (to prevent loops with
187 -- ourselves), extract it.
188 id <- Trans.lift $ mkBinderFor res "foo"
189 change $ Let binds (Let (NonRec id res) (Var id))
191 -- If the result is already a local var, don't extract it.
194 -- Leave all other expressions unchanged
195 letsimpl expr = return expr
196 -- Perform this transform everywhere
197 letsimpltop = everywhere ("letsimpl", letsimpl)
199 --------------------------------
201 --------------------------------
202 -- Takes a let that binds another let, and turns that into two nested lets.
204 -- let b = (let b' = expr' in res') in res
206 -- let b' = expr' in (let b = res' in res)
207 letflat, letflattop :: Transform
208 -- Turn a nonrec let that binds a let into two nested lets.
209 letflat (Let (NonRec b (Let binds res')) res) =
210 change $ Let binds (Let (NonRec b res') res)
211 letflat (Let (Rec binds) expr) = do
212 -- Flatten each binding.
213 binds' <- Utils.concatM $ Monad.mapM flatbind binds
214 -- Return the new let. We don't use change here, since possibly nothing has
215 -- changed. If anything has changed, flatbind has already flagged that
217 return $ Let (Rec binds') expr
219 -- Turns a binding of a let into a multiple bindings, or any other binding
220 -- into a list with just that binding
221 flatbind :: (CoreBndr, CoreExpr) -> TransformMonad [(CoreBndr, CoreExpr)]
222 flatbind (b, Let (Rec binds) expr) = change ((b, expr):binds)
223 flatbind (b, expr) = return [(b, expr)]
224 -- Leave all other expressions unchanged
225 letflat expr = return expr
226 -- Perform this transform everywhere
227 letflattop = everywhere ("letflat", letflat)
229 --------------------------------
231 --------------------------------
232 -- Remove empty (recursive) lets
233 letremove, letremovetop :: Transform
234 letremove (Let (Rec []) res) = change $ res
235 -- Leave all other expressions unchanged
236 letremove expr = return expr
237 -- Perform this transform everywhere
238 letremovetop = everywhere ("letremove", letremove)
240 --------------------------------
241 -- Simple let binding removal
242 --------------------------------
243 -- Remove a = b bindings from let expressions everywhere
244 letremovesimpletop :: Transform
245 letremovesimpletop = everywhere ("letremovesimple", inlinebind (\(b, e) -> Trans.lift $ is_local_var e))
247 --------------------------------
248 -- Unused let binding removal
249 --------------------------------
250 letremoveunused, letremoveunusedtop :: Transform
251 letremoveunused expr@(Let (NonRec b bound) res) = do
252 let used = expr_uses_binders [b] res
256 letremoveunused expr@(Let (Rec binds) res) = do
257 -- Filter out all unused binds.
258 let binds' = filter dobind binds
259 -- Only set the changed flag if binds got removed
260 changeif (length binds' /= length binds) (Let (Rec binds') res)
262 bound_exprs = map snd binds
263 -- For each bind check if the bind is used by res or any of the bound
265 dobind (bndr, _) = any (expr_uses_binders [bndr]) (res:bound_exprs)
266 -- Leave all other expressions unchanged
267 letremoveunused expr = return expr
268 letremoveunusedtop = everywhere ("letremoveunused", letremoveunused)
271 --------------------------------
272 -- Identical let binding merging
273 --------------------------------
274 -- Merge two bindings in a let if they are identical
275 -- TODO: We would very much like to use GHC's CSE module for this, but that
276 -- doesn't track if something changed or not, so we can't use it properly.
277 letmerge, letmergetop :: Transform
278 letmerge expr@(Let _ _) = do
279 let (binds, res) = flattenLets expr
280 binds' <- domerge binds
281 return $ mkNonRecLets binds' res
283 domerge :: [(CoreBndr, CoreExpr)] -> TransformMonad [(CoreBndr, CoreExpr)]
284 domerge [] = return []
286 es' <- mapM (mergebinds e) es
290 -- Uses the second bind to simplify the second bind, if applicable.
291 mergebinds :: (CoreBndr, CoreExpr) -> (CoreBndr, CoreExpr) -> TransformMonad (CoreBndr, CoreExpr)
292 mergebinds (b1, e1) (b2, e2)
293 -- Identical expressions? Replace the second binding with a reference to
295 | CoreUtils.cheapEqExpr e1 e2 = change $ (b2, Var b1)
296 -- Different expressions? Don't change
297 | otherwise = return (b2, e2)
298 -- Leave all other expressions unchanged
299 letmerge expr = return expr
300 letmergetop = everywhere ("letmerge", letmerge)
303 --------------------------------
305 --------------------------------
306 -- Remove a = B bindings, with B :: a -> b, or B :: forall x . T, from let
307 -- expressions everywhere. This means that any value that still needs to be
308 -- applied to something else (polymorphic values need to be applied to a
309 -- Type) will be inlined, and will eventually be applied to all their
312 -- This is a tricky function, which is prone to create loops in the
313 -- transformations. To fix this, we make sure that no transformation will
314 -- create a new let binding with a function type. These other transformations
315 -- will just not work on those function-typed values at first, but the other
316 -- transformations (in particular β-reduction) should make sure that the type
317 -- of those values eventually becomes primitive.
318 inlinenonreptop :: Transform
319 inlinenonreptop = everywhere ("inlinenonrep", inlinebind ((Monad.liftM not) . isRepr . snd))
321 --------------------------------
322 -- Scrutinee simplification
323 --------------------------------
324 scrutsimpl,scrutsimpltop :: Transform
325 -- Don't touch scrutinees that are already simple
326 scrutsimpl expr@(Case (Var _) _ _ _) = return expr
327 -- Replace all other cases with a let that binds the scrutinee and a new
328 -- simple scrutinee, but only when the scrutinee is representable (to prevent
329 -- loops with inlinenonrep, though I don't think a non-representable scrutinee
330 -- will be supported anyway...)
331 scrutsimpl expr@(Case scrut b ty alts) = do
335 id <- Trans.lift $ mkBinderFor scrut "scrut"
336 change $ Let (NonRec id scrut) (Case (Var id) b ty alts)
339 -- Leave all other expressions unchanged
340 scrutsimpl expr = return expr
341 -- Perform this transform everywhere
342 scrutsimpltop = everywhere ("scrutsimpl", scrutsimpl)
344 --------------------------------
345 -- Case binder wildening
346 --------------------------------
347 casesimpl, casesimpltop :: Transform
348 -- This is already a selector case (or, if x does not appear in bndrs, a very
349 -- simple case statement that will be removed by caseremove below). Just leave
351 casesimpl expr@(Case scrut b ty [(con, bndrs, Var x)]) = return expr
352 -- Make sure that all case alternatives have only wild binders and simple
354 -- This is done by creating a new let binding for each non-wild binder, which
355 -- is bound to a new simple selector case statement and for each complex
356 -- expression. We do this only for representable types, to prevent loops with
358 casesimpl expr@(Case scrut b ty alts) = do
359 (bindingss, alts') <- (Monad.liftM unzip) $ mapM doalt alts
360 let bindings = concat bindingss
361 -- Replace the case with a let with bindings and a case
362 let newlet = mkNonRecLets bindings (Case scrut b ty alts')
363 -- If there are no non-wild binders, or this case is already a simple
364 -- selector (i.e., a single alt with exactly one binding), already a simple
365 -- selector altan no bindings (i.e., no wild binders in the original case),
366 -- don't change anything, otherwise, replace the case.
367 if null bindings then return expr else change newlet
369 -- Generate a single wild binder, since they are all the same
370 wild = MkCore.mkWildBinder
371 -- Wilden the binders of one alt, producing a list of bindings as a
373 doalt :: CoreAlt -> TransformMonad ([(CoreBndr, CoreExpr)], CoreAlt)
374 doalt (con, bndrs, expr) = do
375 -- Make each binder wild, if possible
376 bndrs_res <- Monad.zipWithM dobndr bndrs [0..]
377 let (newbndrs, bindings_maybe) = unzip bndrs_res
378 -- Extract a complex expression, if possible. For this we check if any of
379 -- the new list of bndrs are used by expr. We can't use free_vars here,
380 -- since that looks at the old bndrs.
381 let uses_bndrs = not $ VarSet.isEmptyVarSet $ CoreFVs.exprSomeFreeVars (`elem` newbndrs) $ expr
382 (exprbinding_maybe, expr') <- doexpr expr uses_bndrs
383 -- Create a new alternative
384 let newalt = (con, newbndrs, expr')
385 let bindings = Maybe.catMaybes (bindings_maybe ++ [exprbinding_maybe])
386 return (bindings, newalt)
388 -- Make wild alternatives for each binder
389 wildbndrs = map (\bndr -> MkCore.mkWildBinder (Id.idType bndr)) bndrs
390 -- A set of all the binders that are used by the expression
391 free_vars = CoreFVs.exprSomeFreeVars (`elem` bndrs) expr
392 -- Look at the ith binder in the case alternative. Return a new binder
393 -- for it (either the same one, or a wild one) and optionally a let
394 -- binding containing a case expression.
395 dobndr :: CoreBndr -> Int -> TransformMonad (CoreBndr, Maybe (CoreBndr, CoreExpr))
397 repr <- isRepr (Var b)
398 -- Is b wild (e.g., not a free var of expr. Since b is only in scope
399 -- in expr, this means that b is unused if expr does not use it.)
400 let wild = not (VarSet.elemVarSet b free_vars)
401 -- Create a new binding for any representable binder that is not
402 -- already wild and is representable (to prevent loops with
404 if (not wild) && repr
406 -- Create on new binder that will actually capture a value in this
407 -- case statement, and return it.
408 let bty = (Id.idType b)
409 id <- Trans.lift $ mkInternalVar "sel" bty
410 let binders = take i wildbndrs ++ [id] ++ drop (i+1) wildbndrs
411 let caseexpr = Case scrut b bty [(con, binders, Var id)]
412 return (wildbndrs!!i, Just (b, caseexpr))
414 -- Just leave the original binder in place, and don't generate an
415 -- extra selector case.
417 -- Process the expression of a case alternative. Accepts an expression
418 -- and whether this expression uses any of the binders in the
419 -- alternative. Returns an optional new binding and a new expression.
420 doexpr :: CoreExpr -> Bool -> TransformMonad (Maybe (CoreBndr, CoreExpr), CoreExpr)
421 doexpr expr uses_bndrs = do
422 local_var <- Trans.lift $ is_local_var expr
424 -- Extract any expressions that do not use any binders from this
425 -- alternative, is not a local var already and is representable (to
426 -- prevent loops with inlinenonrep).
427 if (not uses_bndrs) && (not local_var) && repr
429 id <- Trans.lift $ mkBinderFor expr "caseval"
430 -- We don't flag a change here, since casevalsimpl will do that above
431 -- based on Just we return here.
432 return $ (Just (id, expr), Var id)
434 -- Don't simplify anything else
435 return (Nothing, expr)
436 -- Leave all other expressions unchanged
437 casesimpl expr = return expr
438 -- Perform this transform everywhere
439 casesimpltop = everywhere ("casesimpl", casesimpl)
441 --------------------------------
443 --------------------------------
444 -- Remove case statements that have only a single alternative and only wild
446 caseremove, caseremovetop :: Transform
447 -- Replace a useless case by the value of its single alternative
448 caseremove (Case scrut b ty [(con, bndrs, expr)]) | not usesvars = change expr
449 -- Find if any of the binders are used by expr
450 where usesvars = (not . VarSet.isEmptyVarSet . (CoreFVs.exprSomeFreeVars (`elem` bndrs))) expr
451 -- Leave all other expressions unchanged
452 caseremove expr = return expr
453 -- Perform this transform everywhere
454 caseremovetop = everywhere ("caseremove", caseremove)
456 --------------------------------
457 -- Argument extraction
458 --------------------------------
459 -- Make sure that all arguments of a representable type are simple variables.
460 appsimpl, appsimpltop :: Transform
461 -- Simplify all representable arguments. Do this by introducing a new Let
462 -- that binds the argument and passing the new binder in the application.
463 appsimpl expr@(App f arg) = do
464 -- Check runtime representability
466 local_var <- Trans.lift $ is_local_var arg
467 if repr && not local_var
468 then do -- Extract representable arguments
469 id <- Trans.lift $ mkBinderFor arg "arg"
470 change $ Let (NonRec id arg) (App f (Var id))
471 else -- Leave non-representable arguments unchanged
473 -- Leave all other expressions unchanged
474 appsimpl expr = return expr
475 -- Perform this transform everywhere
476 appsimpltop = everywhere ("appsimpl", appsimpl)
478 --------------------------------
479 -- Function-typed argument propagation
480 --------------------------------
481 -- Remove all applications to function-typed arguments, by duplication the
482 -- function called with the function-typed parameter replaced by the free
483 -- variables of the argument passed in.
484 argprop, argproptop :: Transform
485 -- Transform any application of a named function (i.e., skip applications of
486 -- lambda's). Also skip applications that have arguments with free type
487 -- variables, since we can't inline those.
488 argprop expr@(App _ _) | is_var fexpr = do
489 -- Find the body of the function called
490 body_maybe <- Trans.lift $ getGlobalBind f
493 -- Process each of the arguments in turn
494 (args', changed) <- Writer.listen $ mapM doarg args
495 -- See if any of the arguments changed
496 case Monoid.getAny changed of
498 let (newargs', newparams', oldargs) = unzip3 args'
499 let newargs = concat newargs'
500 let newparams = concat newparams'
501 -- Create a new body that consists of a lambda for all new arguments and
502 -- the old body applied to some arguments.
503 let newbody = MkCore.mkCoreLams newparams (MkCore.mkCoreApps body oldargs)
504 -- Create a new function with the same name but a new body
505 newf <- Trans.lift $ mkFunction f newbody
506 -- Replace the original application with one of the new function to the
508 change $ MkCore.mkCoreApps (Var newf) newargs
510 -- Don't change the expression if none of the arguments changed
513 -- If we don't have a body for the function called, leave it unchanged (it
514 -- should be a primitive function then).
515 Nothing -> return expr
517 -- Find the function called and the arguments
518 (fexpr, args) = collectArgs expr
521 -- Process a single argument and return (args, bndrs, arg), where args are
522 -- the arguments to replace the given argument in the original
523 -- application, bndrs are the binders to include in the top-level lambda
524 -- in the new function body, and arg is the argument to apply to the old
526 doarg :: CoreExpr -> TransformMonad ([CoreExpr], [CoreBndr], CoreExpr)
529 bndrs <- Trans.lift getGlobalBinders
530 let interesting var = Var.isLocalVar var && (not $ var `elem` bndrs)
531 if not repr && not (is_var arg && interesting (exprToVar arg)) && not (has_free_tyvars arg)
533 -- Propagate all complex arguments that are not representable, but not
534 -- arguments with free type variables (since those would require types
535 -- not known yet, which will always be known eventually).
536 -- Find interesting free variables, each of which should be passed to
537 -- the new function instead of the original function argument.
539 -- Interesting vars are those that are local, but not available from the
540 -- top level scope (functions from this module are defined as local, but
541 -- they're not local to this function, so we can freely move references
542 -- to them into another function).
543 let free_vars = VarSet.varSetElems $ CoreFVs.exprSomeFreeVars interesting arg
544 -- Mark the current expression as changed
546 return (map Var free_vars, free_vars, arg)
548 -- Representable types will not be propagated, and arguments with free
549 -- type variables will be propagated later.
550 -- TODO: preserve original naming?
551 id <- Trans.lift $ mkBinderFor arg "param"
552 -- Just pass the original argument to the new function, which binds it
553 -- to a new id and just pass that new id to the old function body.
554 return ([arg], [id], mkReferenceTo id)
555 -- Leave all other expressions unchanged
556 argprop expr = return expr
557 -- Perform this transform everywhere
558 argproptop = everywhere ("argprop", argprop)
560 --------------------------------
561 -- Function-typed argument extraction
562 --------------------------------
563 -- This transform takes any function-typed argument that cannot be propagated
564 -- (because the function that is applied to it is a builtin function), and
565 -- puts it in a brand new top level binder. This allows us to for example
566 -- apply map to a lambda expression This will not conflict with inlinenonrep,
567 -- since that only inlines local let bindings, not top level bindings.
568 funextract, funextracttop :: Transform
569 funextract expr@(App _ _) | is_var fexpr = do
570 body_maybe <- Trans.lift $ getGlobalBind f
572 -- We don't have a function body for f, so we can perform this transform.
574 -- Find the new arguments
575 args' <- mapM doarg args
576 -- And update the arguments. We use return instead of changed, so the
577 -- changed flag doesn't get set if none of the args got changed.
578 return $ MkCore.mkCoreApps fexpr args'
579 -- We have a function body for f, leave this application to funprop
580 Just _ -> return expr
582 -- Find the function called and the arguments
583 (fexpr, args) = collectArgs expr
585 -- Change any arguments that have a function type, but are not simple yet
586 -- (ie, a variable or application). This means to create a new function
587 -- for map (\f -> ...) b, but not for map (foo a) b.
589 -- We could use is_applicable here instead of is_fun, but I think
590 -- arguments to functions could only have forall typing when existential
591 -- typing is enabled. Not sure, though.
592 doarg arg | not (is_simple arg) && is_fun arg = do
593 -- Create a new top level binding that binds the argument. Its body will
594 -- be extended with lambda expressions, to take any free variables used
595 -- by the argument expression.
596 let free_vars = VarSet.varSetElems $ CoreFVs.exprFreeVars arg
597 let body = MkCore.mkCoreLams free_vars arg
598 id <- Trans.lift $ mkBinderFor body "fun"
599 Trans.lift $ addGlobalBind id body
600 -- Replace the argument with a reference to the new function, applied to
602 change $ MkCore.mkCoreApps (Var id) (map Var free_vars)
603 -- Leave all other arguments untouched
604 doarg arg = return arg
606 -- Leave all other expressions unchanged
607 funextract expr = return expr
608 -- Perform this transform everywhere
609 funextracttop = everywhere ("funextract", funextract)
611 --------------------------------
612 -- End of transformations
613 --------------------------------
618 -- What transforms to run?
619 transforms = [argproptop, funextracttop, etatop, betatop, castproptop, letremovesimpletop, letderectop, letremovetop, letsimpltop, letflattop, scrutsimpltop, casesimpltop, caseremovetop, inlinenonreptop, appsimpltop, letremoveunusedtop, castsimpltop, lambdasimpltop]
621 -- | Returns the normalized version of the given function.
623 CoreBndr -- ^ The function to get
624 -> TranslatorSession CoreExpr -- The normalized function body
626 getNormalized bndr = Utils.makeCached bndr tsNormalized $ do
627 if is_poly (Var bndr)
629 -- This should really only happen at the top level... TODO: Give
630 -- a different error if this happens down in the recursion.
631 error $ "\nNormalize.normalizeBind: Function " ++ show bndr ++ " is polymorphic, can't normalize"
633 expr <- getBinding bndr
634 normalizeExpr (show bndr) expr
636 -- | Normalize an expression
638 String -- ^ What are we normalizing? For debug output only.
639 -> CoreSyn.CoreExpr -- ^ The expression to normalize
640 -> TranslatorSession CoreSyn.CoreExpr -- ^ The normalized expression
642 normalizeExpr what expr = do
643 -- Normalize this expression
644 trace (what ++ " before normalization:\n\n" ++ showSDoc ( ppr expr ) ++ "\n") $ return ()
645 expr' <- dotransforms transforms expr
646 trace ("\n" ++ what ++ " after normalization:\n\n" ++ showSDoc ( ppr expr')) $ return ()
649 -- | Get the value that is bound to the given binder at top level. Fails when
650 -- there is no such binding.
652 CoreBndr -- ^ The binder to get the expression for
653 -> TranslatorSession CoreExpr -- ^ The value bound to the binder
655 getBinding bndr = Utils.makeCached bndr tsBindings $ do
656 -- If the binding isn't in the "cache" (bindings map), then we can't create
657 -- it out of thin air, so return an error.
658 error $ "Normalize.getBinding: Unknown function requested: " ++ show bndr
660 -- | Split a normalized expression into the argument binders, top level
661 -- bindings and the result binder.
663 CoreExpr -- ^ The normalized expression
664 -> ([CoreBndr], [Binding], CoreBndr)
665 splitNormalized expr = (args, binds, res)
667 (args, letexpr) = CoreSyn.collectBinders expr
668 (binds, resexpr) = flattenLets letexpr
669 res = case resexpr of
671 _ -> error $ "Normalize.splitNormalized: Not in normal form: " ++ pprString expr ++ "\n"