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 letflat (Let (NonRec b (Let (NonRec b' expr') res')) res) =
209 change $ Let (NonRec b' expr') (Let (NonRec b res') res)
210 -- Leave all other expressions unchanged
211 letflat expr = return expr
212 -- Perform this transform everywhere
213 letflattop = everywhere ("letflat", letflat)
215 --------------------------------
217 --------------------------------
218 -- Remove empty (recursive) lets
219 letremove, letremovetop :: Transform
220 letremove (Let (Rec []) res) = change $ res
221 -- Leave all other expressions unchanged
222 letremove expr = return expr
223 -- Perform this transform everywhere
224 letremovetop = everywhere ("letremove", letremove)
226 --------------------------------
227 -- Simple let binding removal
228 --------------------------------
229 -- Remove a = b bindings from let expressions everywhere
230 letremovesimpletop :: Transform
231 letremovesimpletop = everywhere ("letremovesimple", inlinebind (\(b, e) -> Trans.lift $ is_local_var e))
233 --------------------------------
234 -- Unused let binding removal
235 --------------------------------
236 letremoveunused, letremoveunusedtop :: Transform
237 letremoveunused expr@(Let _ _) = do
238 -- Filter out all unused binds.
239 let binds' = filter dobind binds
240 -- Only set the changed flag if binds got removed
241 changeif (length binds' /= length binds) (mkNonRecLets binds' res)
243 (binds, res) = flattenLets expr
244 bound_exprs = map snd binds
245 -- For each bind check if the bind is used by res or any of the bound
247 dobind (bndr, _) = any (expr_uses_binders [bndr]) (res:bound_exprs)
248 -- Leave all other expressions unchanged
249 letremoveunused expr = return expr
250 letremoveunusedtop = everywhere ("letremoveunused", letremoveunused)
252 --------------------------------
253 -- Identical let binding merging
254 --------------------------------
255 -- Merge two bindings in a let if they are identical
256 -- TODO: We would very much like to use GHC's CSE module for this, but that
257 -- doesn't track if something changed or not, so we can't use it properly.
258 letmerge, letmergetop :: Transform
259 letmerge expr@(Let _ _) = do
260 let (binds, res) = flattenLets expr
261 binds' <- domerge binds
262 return $ mkNonRecLets binds' res
264 domerge :: [(CoreBndr, CoreExpr)] -> TransformMonad [(CoreBndr, CoreExpr)]
265 domerge [] = return []
267 es' <- mapM (mergebinds e) es
271 -- Uses the second bind to simplify the second bind, if applicable.
272 mergebinds :: (CoreBndr, CoreExpr) -> (CoreBndr, CoreExpr) -> TransformMonad (CoreBndr, CoreExpr)
273 mergebinds (b1, e1) (b2, e2)
274 -- Identical expressions? Replace the second binding with a reference to
276 | CoreUtils.cheapEqExpr e1 e2 = change $ (b2, Var b1)
277 -- Different expressions? Don't change
278 | otherwise = return (b2, e2)
279 -- Leave all other expressions unchanged
280 letmerge expr = return expr
281 letmergetop = everywhere ("letmerge", letmerge)
283 --------------------------------
285 --------------------------------
286 -- Remove a = B bindings, with B :: a -> b, or B :: forall x . T, from let
287 -- expressions everywhere. This means that any value that still needs to be
288 -- applied to something else (polymorphic values need to be applied to a
289 -- Type) will be inlined, and will eventually be applied to all their
292 -- This is a tricky function, which is prone to create loops in the
293 -- transformations. To fix this, we make sure that no transformation will
294 -- create a new let binding with a function type. These other transformations
295 -- will just not work on those function-typed values at first, but the other
296 -- transformations (in particular β-reduction) should make sure that the type
297 -- of those values eventually becomes primitive.
298 inlinenonreptop :: Transform
299 inlinenonreptop = everywhere ("inlinenonrep", inlinebind ((Monad.liftM not) . isRepr . snd))
301 --------------------------------
302 -- Scrutinee simplification
303 --------------------------------
304 scrutsimpl,scrutsimpltop :: Transform
305 -- Don't touch scrutinees that are already simple
306 scrutsimpl expr@(Case (Var _) _ _ _) = return expr
307 -- Replace all other cases with a let that binds the scrutinee and a new
308 -- simple scrutinee, but only when the scrutinee is representable (to prevent
309 -- loops with inlinenonrep, though I don't think a non-representable scrutinee
310 -- will be supported anyway...)
311 scrutsimpl expr@(Case scrut b ty alts) = do
315 id <- Trans.lift $ mkBinderFor scrut "scrut"
316 change $ Let (NonRec id scrut) (Case (Var id) b ty alts)
319 -- Leave all other expressions unchanged
320 scrutsimpl expr = return expr
321 -- Perform this transform everywhere
322 scrutsimpltop = everywhere ("scrutsimpl", scrutsimpl)
324 --------------------------------
325 -- Case binder wildening
326 --------------------------------
327 casesimpl, casesimpltop :: Transform
328 -- This is already a selector case (or, if x does not appear in bndrs, a very
329 -- simple case statement that will be removed by caseremove below). Just leave
331 casesimpl expr@(Case scrut b ty [(con, bndrs, Var x)]) = return expr
332 -- Make sure that all case alternatives have only wild binders and simple
334 -- This is done by creating a new let binding for each non-wild binder, which
335 -- is bound to a new simple selector case statement and for each complex
336 -- expression. We do this only for representable types, to prevent loops with
338 casesimpl expr@(Case scrut b ty alts) = do
339 (bindingss, alts') <- (Monad.liftM unzip) $ mapM doalt alts
340 let bindings = concat bindingss
341 -- Replace the case with a let with bindings and a case
342 let newlet = mkNonRecLets bindings (Case scrut b ty alts')
343 -- If there are no non-wild binders, or this case is already a simple
344 -- selector (i.e., a single alt with exactly one binding), already a simple
345 -- selector altan no bindings (i.e., no wild binders in the original case),
346 -- don't change anything, otherwise, replace the case.
347 if null bindings then return expr else change newlet
349 -- Generate a single wild binder, since they are all the same
350 wild = MkCore.mkWildBinder
351 -- Wilden the binders of one alt, producing a list of bindings as a
353 doalt :: CoreAlt -> TransformMonad ([(CoreBndr, CoreExpr)], CoreAlt)
354 doalt (con, bndrs, expr) = do
355 -- Make each binder wild, if possible
356 bndrs_res <- Monad.zipWithM dobndr bndrs [0..]
357 let (newbndrs, bindings_maybe) = unzip bndrs_res
358 -- Extract a complex expression, if possible. For this we check if any of
359 -- the new list of bndrs are used by expr. We can't use free_vars here,
360 -- since that looks at the old bndrs.
361 let uses_bndrs = not $ VarSet.isEmptyVarSet $ CoreFVs.exprSomeFreeVars (`elem` newbndrs) $ expr
362 (exprbinding_maybe, expr') <- doexpr expr uses_bndrs
363 -- Create a new alternative
364 let newalt = (con, newbndrs, expr')
365 let bindings = Maybe.catMaybes (bindings_maybe ++ [exprbinding_maybe])
366 return (bindings, newalt)
368 -- Make wild alternatives for each binder
369 wildbndrs = map (\bndr -> MkCore.mkWildBinder (Id.idType bndr)) bndrs
370 -- A set of all the binders that are used by the expression
371 free_vars = CoreFVs.exprSomeFreeVars (`elem` bndrs) expr
372 -- Look at the ith binder in the case alternative. Return a new binder
373 -- for it (either the same one, or a wild one) and optionally a let
374 -- binding containing a case expression.
375 dobndr :: CoreBndr -> Int -> TransformMonad (CoreBndr, Maybe (CoreBndr, CoreExpr))
377 repr <- isRepr (Var b)
378 -- Is b wild (e.g., not a free var of expr. Since b is only in scope
379 -- in expr, this means that b is unused if expr does not use it.)
380 let wild = not (VarSet.elemVarSet b free_vars)
381 -- Create a new binding for any representable binder that is not
382 -- already wild and is representable (to prevent loops with
384 if (not wild) && repr
386 -- Create on new binder that will actually capture a value in this
387 -- case statement, and return it.
388 let bty = (Id.idType b)
389 id <- Trans.lift $ mkInternalVar "sel" bty
390 let binders = take i wildbndrs ++ [id] ++ drop (i+1) wildbndrs
391 let caseexpr = Case scrut b bty [(con, binders, Var id)]
392 return (wildbndrs!!i, Just (b, caseexpr))
394 -- Just leave the original binder in place, and don't generate an
395 -- extra selector case.
397 -- Process the expression of a case alternative. Accepts an expression
398 -- and whether this expression uses any of the binders in the
399 -- alternative. Returns an optional new binding and a new expression.
400 doexpr :: CoreExpr -> Bool -> TransformMonad (Maybe (CoreBndr, CoreExpr), CoreExpr)
401 doexpr expr uses_bndrs = do
402 local_var <- Trans.lift $ is_local_var expr
404 -- Extract any expressions that do not use any binders from this
405 -- alternative, is not a local var already and is representable (to
406 -- prevent loops with inlinenonrep).
407 if (not uses_bndrs) && (not local_var) && repr
409 id <- Trans.lift $ mkBinderFor expr "caseval"
410 -- We don't flag a change here, since casevalsimpl will do that above
411 -- based on Just we return here.
412 return $ (Just (id, expr), Var id)
414 -- Don't simplify anything else
415 return (Nothing, expr)
416 -- Leave all other expressions unchanged
417 casesimpl expr = return expr
418 -- Perform this transform everywhere
419 casesimpltop = everywhere ("casesimpl", casesimpl)
421 --------------------------------
423 --------------------------------
424 -- Remove case statements that have only a single alternative and only wild
426 caseremove, caseremovetop :: Transform
427 -- Replace a useless case by the value of its single alternative
428 caseremove (Case scrut b ty [(con, bndrs, expr)]) | not usesvars = change expr
429 -- Find if any of the binders are used by expr
430 where usesvars = (not . VarSet.isEmptyVarSet . (CoreFVs.exprSomeFreeVars (`elem` bndrs))) expr
431 -- Leave all other expressions unchanged
432 caseremove expr = return expr
433 -- Perform this transform everywhere
434 caseremovetop = everywhere ("caseremove", caseremove)
436 --------------------------------
437 -- Argument extraction
438 --------------------------------
439 -- Make sure that all arguments of a representable type are simple variables.
440 appsimpl, appsimpltop :: Transform
441 -- Simplify all representable arguments. Do this by introducing a new Let
442 -- that binds the argument and passing the new binder in the application.
443 appsimpl expr@(App f arg) = do
444 -- Check runtime representability
446 local_var <- Trans.lift $ is_local_var arg
447 if repr && not local_var
448 then do -- Extract representable arguments
449 id <- Trans.lift $ mkBinderFor arg "arg"
450 change $ Let (NonRec id arg) (App f (Var id))
451 else -- Leave non-representable arguments unchanged
453 -- Leave all other expressions unchanged
454 appsimpl expr = return expr
455 -- Perform this transform everywhere
456 appsimpltop = everywhere ("appsimpl", appsimpl)
458 --------------------------------
459 -- Function-typed argument propagation
460 --------------------------------
461 -- Remove all applications to function-typed arguments, by duplication the
462 -- function called with the function-typed parameter replaced by the free
463 -- variables of the argument passed in.
464 argprop, argproptop :: Transform
465 -- Transform any application of a named function (i.e., skip applications of
466 -- lambda's). Also skip applications that have arguments with free type
467 -- variables, since we can't inline those.
468 argprop expr@(App _ _) | is_var fexpr = do
469 -- Find the body of the function called
470 body_maybe <- Trans.lift $ getGlobalBind f
473 -- Process each of the arguments in turn
474 (args', changed) <- Writer.listen $ mapM doarg args
475 -- See if any of the arguments changed
476 case Monoid.getAny changed of
478 let (newargs', newparams', oldargs) = unzip3 args'
479 let newargs = concat newargs'
480 let newparams = concat newparams'
481 -- Create a new body that consists of a lambda for all new arguments and
482 -- the old body applied to some arguments.
483 let newbody = MkCore.mkCoreLams newparams (MkCore.mkCoreApps body oldargs)
484 -- Create a new function with the same name but a new body
485 newf <- Trans.lift $ mkFunction f newbody
486 -- Replace the original application with one of the new function to the
488 change $ MkCore.mkCoreApps (Var newf) newargs
490 -- Don't change the expression if none of the arguments changed
493 -- If we don't have a body for the function called, leave it unchanged (it
494 -- should be a primitive function then).
495 Nothing -> return expr
497 -- Find the function called and the arguments
498 (fexpr, args) = collectArgs expr
501 -- Process a single argument and return (args, bndrs, arg), where args are
502 -- the arguments to replace the given argument in the original
503 -- application, bndrs are the binders to include in the top-level lambda
504 -- in the new function body, and arg is the argument to apply to the old
506 doarg :: CoreExpr -> TransformMonad ([CoreExpr], [CoreBndr], CoreExpr)
509 bndrs <- Trans.lift getGlobalBinders
510 let interesting var = Var.isLocalVar var && (not $ var `elem` bndrs)
511 if not repr && not (is_var arg && interesting (exprToVar arg)) && not (has_free_tyvars arg)
513 -- Propagate all complex arguments that are not representable, but not
514 -- arguments with free type variables (since those would require types
515 -- not known yet, which will always be known eventually).
516 -- Find interesting free variables, each of which should be passed to
517 -- the new function instead of the original function argument.
519 -- Interesting vars are those that are local, but not available from the
520 -- top level scope (functions from this module are defined as local, but
521 -- they're not local to this function, so we can freely move references
522 -- to them into another function).
523 let free_vars = VarSet.varSetElems $ CoreFVs.exprSomeFreeVars interesting arg
524 -- Mark the current expression as changed
526 return (map Var free_vars, free_vars, arg)
528 -- Representable types will not be propagated, and arguments with free
529 -- type variables will be propagated later.
530 -- TODO: preserve original naming?
531 id <- Trans.lift $ mkBinderFor arg "param"
532 -- Just pass the original argument to the new function, which binds it
533 -- to a new id and just pass that new id to the old function body.
534 return ([arg], [id], mkReferenceTo id)
535 -- Leave all other expressions unchanged
536 argprop expr = return expr
537 -- Perform this transform everywhere
538 argproptop = everywhere ("argprop", argprop)
540 --------------------------------
541 -- Function-typed argument extraction
542 --------------------------------
543 -- This transform takes any function-typed argument that cannot be propagated
544 -- (because the function that is applied to it is a builtin function), and
545 -- puts it in a brand new top level binder. This allows us to for example
546 -- apply map to a lambda expression This will not conflict with inlinenonrep,
547 -- since that only inlines local let bindings, not top level bindings.
548 funextract, funextracttop :: Transform
549 funextract expr@(App _ _) | is_var fexpr = do
550 body_maybe <- Trans.lift $ getGlobalBind f
552 -- We don't have a function body for f, so we can perform this transform.
554 -- Find the new arguments
555 args' <- mapM doarg args
556 -- And update the arguments. We use return instead of changed, so the
557 -- changed flag doesn't get set if none of the args got changed.
558 return $ MkCore.mkCoreApps fexpr args'
559 -- We have a function body for f, leave this application to funprop
560 Just _ -> return expr
562 -- Find the function called and the arguments
563 (fexpr, args) = collectArgs expr
565 -- Change any arguments that have a function type, but are not simple yet
566 -- (ie, a variable or application). This means to create a new function
567 -- for map (\f -> ...) b, but not for map (foo a) b.
569 -- We could use is_applicable here instead of is_fun, but I think
570 -- arguments to functions could only have forall typing when existential
571 -- typing is enabled. Not sure, though.
572 doarg arg | not (is_simple arg) && is_fun arg = do
573 -- Create a new top level binding that binds the argument. Its body will
574 -- be extended with lambda expressions, to take any free variables used
575 -- by the argument expression.
576 let free_vars = VarSet.varSetElems $ CoreFVs.exprFreeVars arg
577 let body = MkCore.mkCoreLams free_vars arg
578 id <- Trans.lift $ mkBinderFor body "fun"
579 Trans.lift $ addGlobalBind id body
580 -- Replace the argument with a reference to the new function, applied to
582 change $ MkCore.mkCoreApps (Var id) (map Var free_vars)
583 -- Leave all other arguments untouched
584 doarg arg = return arg
586 -- Leave all other expressions unchanged
587 funextract expr = return expr
588 -- Perform this transform everywhere
589 funextracttop = everywhere ("funextract", funextract)
591 --------------------------------
592 -- End of transformations
593 --------------------------------
598 -- What transforms to run?
599 transforms = [argproptop, funextracttop, etatop, betatop, castproptop, letremovesimpletop, letderectop, letremovetop, letsimpltop, letflattop, scrutsimpltop, casesimpltop, caseremovetop, inlinenonreptop, appsimpltop, letmergetop, letremoveunusedtop, castsimpltop, lambdasimpltop]
601 -- | Returns the normalized version of the given function.
603 CoreBndr -- ^ The function to get
604 -> TranslatorSession CoreExpr -- The normalized function body
606 getNormalized bndr = Utils.makeCached bndr tsNormalized $ do
607 if is_poly (Var bndr)
609 -- This should really only happen at the top level... TODO: Give
610 -- a different error if this happens down in the recursion.
611 error $ "\nNormalize.normalizeBind: Function " ++ show bndr ++ " is polymorphic, can't normalize"
613 expr <- getBinding bndr
614 normalizeExpr (show bndr) expr
616 -- | Normalize an expression
618 String -- ^ What are we normalizing? For debug output only.
619 -> CoreSyn.CoreExpr -- ^ The expression to normalize
620 -> TranslatorSession CoreSyn.CoreExpr -- ^ The normalized expression
622 normalizeExpr what expr = do
623 -- Normalize this expression
624 trace (what ++ " before normalization:\n\n" ++ showSDoc ( ppr expr ) ++ "\n") $ return ()
625 expr' <- dotransforms transforms expr
626 trace ("\n" ++ what ++ " after normalization:\n\n" ++ showSDoc ( ppr expr')) $ return ()
629 -- | Get the value that is bound to the given binder at top level. Fails when
630 -- there is no such binding.
632 CoreBndr -- ^ The binder to get the expression for
633 -> TranslatorSession CoreExpr -- ^ The value bound to the binder
635 getBinding bndr = Utils.makeCached bndr tsBindings $ do
636 -- If the binding isn't in the "cache" (bindings map), then we can't create
637 -- it out of thin air, so return an error.
638 error $ "Normalize.getBinding: Unknown function requested: " ++ show bndr
640 -- | Split a normalized expression into the argument binders, top level
641 -- bindings and the result binder.
643 CoreExpr -- ^ The normalized expression
644 -> ([CoreBndr], [Binding], CoreBndr)
645 splitNormalized expr = (args, binds, res)
647 (args, letexpr) = CoreSyn.collectBinders expr
648 (binds, resexpr) = flattenLets letexpr
649 res = case resexpr of
651 _ -> error $ "Normalize.splitNormalized: Not in normal form: " ++ pprString expr ++ "\n"