2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[CoreUtils]{Utility functions on @Core@ syntax}
9 mkNote, mkInlineMe, mkSCC, mkCoerce,
10 bindNonRec, mkIfThenElse, mkAltExpr,
13 -- Properties of expressions
14 exprType, coreAltsType,
15 exprIsBottom, exprIsDupable, exprIsTrivial, exprIsCheap,
16 exprIsValue,exprOkForSpeculation, exprIsBig,
18 idAppIsBottom, idAppIsCheap,
21 -- Expr transformation
23 exprArity, exprEtaExpandArity,
32 cheapEqExpr, eqExpr, applyTypeToArgs
35 #include "HsVersions.h"
38 import GlaExts -- For `xori`
41 import CoreFVs ( exprFreeVars )
42 import PprCore ( pprCoreExpr )
43 import Var ( Var, isId, isTyVar )
46 import Name ( hashName )
47 import Literal ( hashLiteral, literalType, litIsDupable )
48 import DataCon ( DataCon, dataConRepArity )
49 import PrimOp ( primOpOkForSpeculation, primOpIsCheap,
51 import Id ( Id, idType, idFlavour, idStrictness, idLBVarInfo,
52 mkWildId, idArity, idName, idUnfolding, idInfo,
53 isDataConId_maybe, isPrimOpId_maybe, mkSysLocal
55 import IdInfo ( LBVarInfo(..),
58 import Demand ( appIsBottom )
59 import Type ( Type, mkFunTy, mkForAllTy, splitFunTy_maybe,
60 applyTys, isUnLiftedType, seqType, mkUTy, mkTyVarTy,
61 splitForAllTy_maybe, splitNewType_maybe
63 import TysWiredIn ( boolTy, trueDataCon, falseDataCon )
64 import CostCentre ( CostCentre )
65 import UniqSupply ( UniqSupply, splitUniqSupply, uniqFromSupply )
66 import Maybes ( maybeToBool )
68 import TysPrim ( alphaTy ) -- Debugging only
72 %************************************************************************
74 \subsection{Find the type of a Core atom/expression}
76 %************************************************************************
79 exprType :: CoreExpr -> Type
81 exprType (Var var) = idType var
82 exprType (Lit lit) = literalType lit
83 exprType (Let _ body) = exprType body
84 exprType (Case _ _ alts) = coreAltsType alts
85 exprType (Note (Coerce ty _) e) = ty -- **! should take usage from e
86 exprType (Note other_note e) = exprType e
87 exprType (Lam binder expr) = mkPiType binder (exprType expr)
89 = case collectArgs e of
90 (fun, args) -> applyTypeToArgs e (exprType fun) args
92 exprType other = pprTrace "exprType" (pprCoreExpr other) alphaTy
94 coreAltsType :: [CoreAlt] -> Type
95 coreAltsType ((_,_,rhs) : _) = exprType rhs
98 @mkPiType@ makes a (->) type or a forall type, depending on whether
99 it is given a type variable or a term variable. We cleverly use the
100 lbvarinfo field to figure out the right annotation for the arrove in
101 case of a term variable.
104 mkPiType :: Var -> Type -> Type -- The more polymorphic version doesn't work...
105 mkPiType v ty | isId v = (case idLBVarInfo v of
106 LBVarInfo u -> mkUTy u
108 mkFunTy (idType v) ty
109 | isTyVar v = mkForAllTy v ty
113 -- The first argument is just for debugging
114 applyTypeToArgs :: CoreExpr -> Type -> [CoreExpr] -> Type
115 applyTypeToArgs e op_ty [] = op_ty
117 applyTypeToArgs e op_ty (Type ty : args)
118 = -- Accumulate type arguments so we can instantiate all at once
119 applyTypeToArgs e (applyTys op_ty tys) rest_args
121 (tys, rest_args) = go [ty] args
122 go tys (Type ty : args) = go (ty:tys) args
123 go tys rest_args = (reverse tys, rest_args)
125 applyTypeToArgs e op_ty (other_arg : args)
126 = case (splitFunTy_maybe op_ty) of
127 Just (_, res_ty) -> applyTypeToArgs e res_ty args
128 Nothing -> pprPanic "applyTypeToArgs" (pprCoreExpr e)
133 %************************************************************************
135 \subsection{Attaching notes}
137 %************************************************************************
139 mkNote removes redundant coercions, and SCCs where possible
142 mkNote :: Note -> CoreExpr -> CoreExpr
143 mkNote (Coerce to_ty from_ty) expr = mkCoerce to_ty from_ty expr
144 mkNote (SCC cc) expr = mkSCC cc expr
145 mkNote InlineMe expr = mkInlineMe expr
146 mkNote note expr = Note note expr
148 -- Slide InlineCall in around the function
149 -- No longer necessary I think (SLPJ Apr 99)
150 -- mkNote InlineCall (App f a) = App (mkNote InlineCall f) a
151 -- mkNote InlineCall (Var v) = Note InlineCall (Var v)
152 -- mkNote InlineCall expr = expr
155 Drop trivial InlineMe's. This is somewhat important, because if we have an unfolding
156 that looks like (Note InlineMe (Var v)), the InlineMe doesn't go away because it may
157 not be *applied* to anything.
159 We don't use exprIsTrivial here, though, because we sometimes generate worker/wrapper
162 f = inline_me (coerce t fw)
163 As usual, the inline_me prevents the worker from getting inlined back into the wrapper.
164 We want the split, so that the coerces can cancel at the call site.
167 mkInlineMe (Var v) = Var v
168 mkInlineMe e = Note InlineMe e
174 mkCoerce :: Type -> Type -> CoreExpr -> CoreExpr
176 mkCoerce to_ty from_ty (Note (Coerce to_ty2 from_ty2) expr)
177 = ASSERT( from_ty == to_ty2 )
178 mkCoerce to_ty from_ty2 expr
180 mkCoerce to_ty from_ty expr
181 | to_ty == from_ty = expr
182 | otherwise = ASSERT( from_ty == exprType expr )
183 Note (Coerce to_ty from_ty) expr
187 mkSCC :: CostCentre -> Expr b -> Expr b
188 -- Note: Nested SCC's *are* preserved for the benefit of
189 -- cost centre stack profiling (Durham)
191 mkSCC cc (Lit lit) = Lit lit
192 mkSCC cc (Lam x e) = Lam x (mkSCC cc e) -- Move _scc_ inside lambda
193 mkSCC cc expr = Note (SCC cc) expr
197 %************************************************************************
199 \subsection{Other expression construction}
201 %************************************************************************
204 bindNonRec :: Id -> CoreExpr -> CoreExpr -> CoreExpr
205 -- (bindNonRec x r b) produces either
208 -- case r of x { _DEFAULT_ -> b }
210 -- depending on whether x is unlifted or not
211 -- It's used by the desugarer to avoid building bindings
212 -- that give Core Lint a heart attack. Actually the simplifier
213 -- deals with them perfectly well.
214 bindNonRec bndr rhs body
215 | isUnLiftedType (idType bndr) = Case rhs bndr [(DEFAULT,[],body)]
216 | otherwise = Let (NonRec bndr rhs) body
220 mkAltExpr :: AltCon -> [CoreBndr] -> [Type] -> CoreExpr
221 -- This guy constructs the value that the scrutinee must have
222 -- when you are in one particular branch of a case
223 mkAltExpr (DataAlt con) args inst_tys
224 = mkConApp con (map Type inst_tys ++ map varToCoreExpr args)
225 mkAltExpr (LitAlt lit) [] []
228 mkIfThenElse :: CoreExpr -> CoreExpr -> CoreExpr -> CoreExpr
229 mkIfThenElse guard then_expr else_expr
230 = Case guard (mkWildId boolTy)
231 [ (DataAlt trueDataCon, [], then_expr),
232 (DataAlt falseDataCon, [], else_expr) ]
235 %************************************************************************
237 \subsection{Figuring out things about expressions}
239 %************************************************************************
241 @exprIsTrivial@ is true of expressions we are unconditionally happy to
242 duplicate; simple variables and constants, and type
243 applications. Note that primop Ids aren't considered
246 @exprIsBottom@ is true of expressions that are guaranteed to diverge
250 exprIsTrivial (Var v)
251 | Just op <- isPrimOpId_maybe v = primOpIsDupable op
253 exprIsTrivial (Type _) = True
254 exprIsTrivial (Lit lit) = True
255 exprIsTrivial (App e arg) = isTypeArg arg && exprIsTrivial e
256 exprIsTrivial (Note _ e) = exprIsTrivial e
257 exprIsTrivial (Lam b body) | isTyVar b = exprIsTrivial body
258 exprIsTrivial other = False
262 @exprIsDupable@ is true of expressions that can be duplicated at a modest
263 cost in code size. This will only happen in different case
264 branches, so there's no issue about duplicating work.
266 That is, exprIsDupable returns True of (f x) even if
267 f is very very expensive to call.
269 Its only purpose is to avoid fruitless let-binding
270 and then inlining of case join points
274 exprIsDupable (Type _) = True
275 exprIsDupable (Var v) = True
276 exprIsDupable (Lit lit) = litIsDupable lit
277 exprIsDupable (Note _ e) = exprIsDupable e
281 go (Var v) n_args = True
282 go (App f a) n_args = n_args < dupAppSize
285 go other n_args = False
288 dupAppSize = 4 -- Size of application we are prepared to duplicate
291 @exprIsCheap@ looks at a Core expression and returns \tr{True} if
292 it is obviously in weak head normal form, or is cheap to get to WHNF.
293 [Note that that's not the same as exprIsDupable; an expression might be
294 big, and hence not dupable, but still cheap.]
296 By ``cheap'' we mean a computation we're willing to:
297 push inside a lambda, or
298 inline at more than one place
299 That might mean it gets evaluated more than once, instead of being
300 shared. The main examples of things which aren't WHNF but are
305 (where e, and all the ei are cheap)
308 (where e and b are cheap)
311 (where op is a cheap primitive operator)
314 (because we are happy to substitute it inside a lambda)
316 Notice that a variable is considered 'cheap': we can push it inside a lambda,
317 because sharing will make sure it is only evaluated once.
320 exprIsCheap :: CoreExpr -> Bool
321 exprIsCheap (Lit lit) = True
322 exprIsCheap (Type _) = True
323 exprIsCheap (Var _) = True
324 exprIsCheap (Note _ e) = exprIsCheap e
325 exprIsCheap (Lam x e) = if isId x then True else exprIsCheap e
326 exprIsCheap (Case e _ alts) = exprIsCheap e &&
327 and [exprIsCheap rhs | (_,_,rhs) <- alts]
328 -- Experimentally, treat (case x of ...) as cheap
329 -- (and case __coerce x etc.)
330 -- This improves arities of overloaded functions where
331 -- there is only dictionary selection (no construction) involved
332 exprIsCheap (Let (NonRec x _) e)
333 | isUnLiftedType (idType x) = exprIsCheap e
335 -- strict lets always have cheap right hand sides, and
338 exprIsCheap other_expr
339 = go other_expr 0 True
341 go (Var f) n_args args_cheap
342 = (idAppIsCheap f n_args && args_cheap)
343 -- A constructor, cheap primop, or partial application
345 || idAppIsBottom f n_args
346 -- Application of a function which
347 -- always gives bottom; we treat this as cheap
348 -- because it certainly doesn't need to be shared!
350 go (App f a) n_args args_cheap
351 | isTypeArg a = go f n_args args_cheap
352 | otherwise = go f (n_args + 1) (exprIsCheap a && args_cheap)
354 go other n_args args_cheap = False
356 idAppIsCheap :: Id -> Int -> Bool
357 idAppIsCheap id n_val_args
358 | n_val_args == 0 = True -- Just a type application of
359 -- a variable (f t1 t2 t3)
361 | otherwise = case idFlavour id of
363 RecordSelId _ -> True -- I'm experimenting with making record selection
364 -- look cheap, so we will substitute it inside a
365 -- lambda. Particularly for dictionary field selection
367 PrimOpId op -> primOpIsCheap op -- In principle we should worry about primops
368 -- that return a type variable, since the result
369 -- might be applied to something, but I'm not going
370 -- to bother to check the number of args
371 other -> n_val_args < idArity id
374 exprOkForSpeculation returns True of an expression that it is
376 * safe to evaluate even if normal order eval might not
377 evaluate the expression at all, or
379 * safe *not* to evaluate even if normal order would do so
383 the expression guarantees to terminate,
385 without raising an exception,
386 without causing a side effect (e.g. writing a mutable variable)
389 let x = case y# +# 1# of { r# -> I# r# }
392 case y# +# 1# of { r# ->
397 We can only do this if the (y+1) is ok for speculation: it has no
398 side effects, and can't diverge or raise an exception.
401 exprOkForSpeculation :: CoreExpr -> Bool
402 exprOkForSpeculation (Lit _) = True
403 exprOkForSpeculation (Var v) = isUnLiftedType (idType v)
404 exprOkForSpeculation (Note _ e) = exprOkForSpeculation e
405 exprOkForSpeculation other_expr
406 = go other_expr 0 True
408 go (Var f) n_args args_ok
409 = case idFlavour f of
410 DataConId _ -> True -- The strictness of the constructor has already
411 -- been expressed by its "wrapper", so we don't need
412 -- to take the arguments into account
414 PrimOpId op -> primOpOkForSpeculation op && args_ok
415 -- A bit conservative: we don't really need
416 -- to care about lazy arguments, but this is easy
420 go (App f a) n_args args_ok
421 | isTypeArg a = go f n_args args_ok
422 | otherwise = go f (n_args + 1) (exprOkForSpeculation a && args_ok)
424 go other n_args args_ok = False
429 exprIsBottom :: CoreExpr -> Bool -- True => definitely bottom
430 exprIsBottom e = go 0 e
432 -- n is the number of args
433 go n (Note _ e) = go n e
434 go n (Let _ e) = go n e
435 go n (Case e _ _) = go 0 e -- Just check the scrut
436 go n (App e _) = go (n+1) e
437 go n (Var v) = idAppIsBottom v n
439 go n (Lam _ _) = False
441 idAppIsBottom :: Id -> Int -> Bool
442 idAppIsBottom id n_val_args = appIsBottom (idStrictness id) n_val_args
445 @exprIsValue@ returns true for expressions that are certainly *already*
446 evaluated to WHNF. This is used to decide wether it's ok to change
447 case x of _ -> e ===> e
449 and to decide whether it's safe to discard a `seq`
451 So, it does *not* treat variables as evaluated, unless they say they are
454 exprIsValue :: CoreExpr -> Bool -- True => Value-lambda, constructor, PAP
455 exprIsValue (Type ty) = True -- Types are honorary Values; we don't mind
457 exprIsValue (Lit l) = True
458 exprIsValue (Lam b e) = isId b || exprIsValue e
459 exprIsValue (Note _ e) = exprIsValue e
460 exprIsValue other_expr
463 go (Var f) n_args = idAppIsValue f n_args
466 | isTypeArg a = go f n_args
467 | otherwise = go f (n_args + 1)
469 go (Note _ f) n_args = go f n_args
471 go other n_args = False
473 idAppIsValue :: Id -> Int -> Bool
474 idAppIsValue id n_val_args
475 = case idFlavour id of
477 PrimOpId _ -> n_val_args < idArity id
478 other | n_val_args == 0 -> isEvaldUnfolding (idUnfolding id)
479 | otherwise -> n_val_args < idArity id
480 -- A worry: what if an Id's unfolding is just itself:
481 -- then we could get an infinite loop...
485 exprIsConApp_maybe :: CoreExpr -> Maybe (DataCon, [CoreExpr])
486 exprIsConApp_maybe expr
487 = analyse (collectArgs expr)
489 analyse (Var fun, args)
490 | maybeToBool maybe_con_app = maybe_con_app
492 maybe_con_app = case isDataConId_maybe fun of
493 Just con | length args >= dataConRepArity con
494 -- Might be > because the arity excludes type args
498 analyse (Var fun, [])
499 = case maybeUnfoldingTemplate (idUnfolding fun) of
501 Just unf -> exprIsConApp_maybe unf
503 analyse other = Nothing
506 The arity of an expression (in the code-generator sense, i.e. the
507 number of lambdas at the beginning).
510 exprArity :: CoreExpr -> Int
512 | isTyVar x = exprArity e
513 | otherwise = 1 + exprArity e
515 -- Ignore coercions. Top level sccs are removed by the final
516 -- profiling pass, so we ignore those too.
522 %************************************************************************
524 \subsection{Eta reduction and expansion}
526 %************************************************************************
528 @etaReduce@ trys an eta reduction at the top level of a Core Expr.
530 e.g. \ x y -> f x y ===> f
532 But we only do this if it gets rid of a whole lambda, not part.
533 The idea is that lambdas are often quite helpful: they indicate
534 head normal forms, so we don't want to chuck them away lightly.
537 etaReduce :: CoreExpr -> CoreExpr
538 -- ToDo: we should really check that we don't turn a non-bottom
539 -- lambda into a bottom variable. Sigh
541 etaReduce expr@(Lam bndr body)
542 = check (reverse binders) body
544 (binders, body) = collectBinders expr
547 | not (any (`elemVarSet` body_fvs) binders)
550 body_fvs = exprFreeVars body
552 check (b : bs) (App fun arg)
553 | (varToCoreExpr b `cheapEqExpr` arg)
556 check _ _ = expr -- Bale out
558 etaReduce expr = expr -- The common case
563 exprEtaExpandArity :: CoreExpr -> (Int, Bool)
564 -- The Int is number of value args the thing can be
565 -- applied to without doing much work
566 -- The Bool is True iff there are enough explicit value lambdas
567 -- at the top to make this arity apparent
568 -- (but ignore it when arity==0)
570 -- This is used when eta expanding
571 -- e ==> \xy -> e x y
573 -- It returns 1 (or more) to:
574 -- case x of p -> \s -> ...
575 -- because for I/O ish things we really want to get that \s to the top.
576 -- We are prepared to evaluate x each time round the loop in order to get that
577 -- Hence "generous" arity
582 go ar (Lam x e) | isId x = go (ar+1) e
583 | otherwise = go ar e
584 go ar (Note n e) | ok_note n = go ar e
585 go ar other = (ar + ar', ar' == 0)
587 ar' = go1 other `max` 0
589 go1 (Var v) = idArity v
590 go1 (Lam x e) | isId x = go1 e + 1
592 go1 (Note n e) | ok_note n = go1 e
593 go1 (App f (Type _)) = go1 f
594 go1 (App f a) | exprIsCheap a = go1 f - 1
595 go1 (Case scrut _ alts)
596 | exprIsCheap scrut = min_zero [go1 rhs | (_,_,rhs) <- alts]
598 | all exprIsCheap (rhssOfBind b) = go1 e
602 ok_note (Coerce _ _) = True
603 ok_note InlineCall = True
604 ok_note other = False
605 -- Notice that we do not look through __inline_me__
606 -- This one is a bit more surprising, but consider
607 -- f = _inline_me (\x -> e)
608 -- We DO NOT want to eta expand this to
609 -- f = \x -> (_inline_me (\x -> e)) x
610 -- because the _inline_me gets dropped now it is applied,
615 min_zero :: [Int] -> Int -- Find the minimum, but zero is the smallest
616 min_zero (x:xs) = go x xs
618 go 0 xs = 0 -- Nothing beats zero
620 go min (x:xs) | x < min = go x xs
621 | otherwise = go min xs
627 etaExpand :: Int -- Add this number of value args
629 -> CoreExpr -> Type -- Expression and its type
631 -- (etaExpand n us e ty) returns an expression with
632 -- the same meaning as 'e', but with arity 'n'.
634 -- Given e' = etaExpand n us e ty
636 -- ty = exprType e = exprType e'
638 -- etaExpand deals with for-alls and coerces. For example:
640 -- where E :: forall a. T
641 -- newtype T = MkT (A -> B)
644 -- (/\b. coerce T (\y::A -> (coerce (A->B) (E b) y)
646 -- (case x of { I# x -> /\ a -> coerce T E)
648 etaExpand n us expr ty
649 | n == 0 -- Saturated, so nothing to do
652 | otherwise -- An unsaturated constructor or primop; eta expand it
653 = case splitForAllTy_maybe ty of {
654 Just (tv,ty') -> Lam tv (etaExpand n us (App expr (Type (mkTyVarTy tv))) ty')
658 case splitFunTy_maybe ty of {
659 Just (arg_ty, res_ty) -> Lam arg1 (etaExpand (n-1) us2 (App expr (Var arg1)) res_ty)
661 arg1 = mkSysLocal SLIT("eta") uniq arg_ty
662 (us1, us2) = splitUniqSupply us
663 uniq = uniqFromSupply us1
667 case splitNewType_maybe ty of {
668 Just ty' -> mkCoerce ty ty' (etaExpand n us (mkCoerce ty' ty expr) ty') ;
670 Nothing -> pprTrace "Bad eta expand" (ppr expr $$ ppr ty) expr
675 %************************************************************************
677 \subsection{Equality}
679 %************************************************************************
681 @cheapEqExpr@ is a cheap equality test which bales out fast!
682 True => definitely equal
683 False => may or may not be equal
686 cheapEqExpr :: Expr b -> Expr b -> Bool
688 cheapEqExpr (Var v1) (Var v2) = v1==v2
689 cheapEqExpr (Lit lit1) (Lit lit2) = lit1 == lit2
690 cheapEqExpr (Type t1) (Type t2) = t1 == t2
692 cheapEqExpr (App f1 a1) (App f2 a2)
693 = f1 `cheapEqExpr` f2 && a1 `cheapEqExpr` a2
695 cheapEqExpr _ _ = False
697 exprIsBig :: Expr b -> Bool
698 -- Returns True of expressions that are too big to be compared by cheapEqExpr
699 exprIsBig (Lit _) = False
700 exprIsBig (Var v) = False
701 exprIsBig (Type t) = False
702 exprIsBig (App f a) = exprIsBig f || exprIsBig a
703 exprIsBig other = True
708 eqExpr :: CoreExpr -> CoreExpr -> Bool
709 -- Works ok at more general type, but only needed at CoreExpr
711 = eq emptyVarEnv e1 e2
713 -- The "env" maps variables in e1 to variables in ty2
714 -- So when comparing lambdas etc,
715 -- we in effect substitute v2 for v1 in e1 before continuing
716 eq env (Var v1) (Var v2) = case lookupVarEnv env v1 of
717 Just v1' -> v1' == v2
720 eq env (Lit lit1) (Lit lit2) = lit1 == lit2
721 eq env (App f1 a1) (App f2 a2) = eq env f1 f2 && eq env a1 a2
722 eq env (Lam v1 e1) (Lam v2 e2) = eq (extendVarEnv env v1 v2) e1 e2
723 eq env (Let (NonRec v1 r1) e1)
724 (Let (NonRec v2 r2) e2) = eq env r1 r2 && eq (extendVarEnv env v1 v2) e1 e2
725 eq env (Let (Rec ps1) e1)
726 (Let (Rec ps2) e2) = length ps1 == length ps2 &&
727 and (zipWith eq_rhs ps1 ps2) &&
730 env' = extendVarEnvList env [(v1,v2) | ((v1,_),(v2,_)) <- zip ps1 ps2]
731 eq_rhs (_,r1) (_,r2) = eq env' r1 r2
732 eq env (Case e1 v1 a1)
733 (Case e2 v2 a2) = eq env e1 e2 &&
734 length a1 == length a2 &&
735 and (zipWith (eq_alt env') a1 a2)
737 env' = extendVarEnv env v1 v2
739 eq env (Note n1 e1) (Note n2 e2) = eq_note env n1 n2 && eq env e1 e2
740 eq env (Type t1) (Type t2) = t1 == t2
743 eq_list env [] [] = True
744 eq_list env (e1:es1) (e2:es2) = eq env e1 e2 && eq_list env es1 es2
745 eq_list env es1 es2 = False
747 eq_alt env (c1,vs1,r1) (c2,vs2,r2) = c1==c2 &&
748 eq (extendVarEnvList env (vs1 `zip` vs2)) r1 r2
750 eq_note env (SCC cc1) (SCC cc2) = cc1 == cc2
751 eq_note env (Coerce t1 f1) (Coerce t2 f2) = t1==t2 && f1==f2
752 eq_note env InlineCall InlineCall = True
753 eq_note env other1 other2 = False
757 %************************************************************************
759 \subsection{The size of an expression}
761 %************************************************************************
764 coreBindsSize :: [CoreBind] -> Int
765 coreBindsSize bs = foldr ((+) . bindSize) 0 bs
767 exprSize :: CoreExpr -> Int
768 -- A measure of the size of the expressions
769 -- It also forces the expression pretty drastically as a side effect
770 exprSize (Var v) = varSize v
771 exprSize (Lit lit) = lit `seq` 1
772 exprSize (App f a) = exprSize f + exprSize a
773 exprSize (Lam b e) = varSize b + exprSize e
774 exprSize (Let b e) = bindSize b + exprSize e
775 exprSize (Case e b as) = exprSize e + varSize b + foldr ((+) . altSize) 0 as
776 exprSize (Note n e) = noteSize n + exprSize e
777 exprSize (Type t) = seqType t `seq` 1
779 noteSize (SCC cc) = cc `seq` 1
780 noteSize (Coerce t1 t2) = seqType t1 `seq` seqType t2 `seq` 1
781 noteSize InlineCall = 1
782 noteSize InlineMe = 1
784 varSize :: Var -> Int
785 varSize b | isTyVar b = 1
786 | otherwise = seqType (idType b) `seq`
787 megaSeqIdInfo (idInfo b) `seq`
790 varsSize = foldr ((+) . varSize) 0
792 bindSize (NonRec b e) = varSize b + exprSize e
793 bindSize (Rec prs) = foldr ((+) . pairSize) 0 prs
795 pairSize (b,e) = varSize b + exprSize e
797 altSize (c,bs,e) = c `seq` varsSize bs + exprSize e
801 %************************************************************************
805 %************************************************************************
808 hashExpr :: CoreExpr -> Int
809 hashExpr e | hash < 0 = 77 -- Just in case we hit -maxInt
812 hash = abs (hash_expr e) -- Negative numbers kill UniqFM
814 hash_expr (Note _ e) = hash_expr e
815 hash_expr (Let (NonRec b r) e) = hashId b
816 hash_expr (Let (Rec ((b,r):_)) e) = hashId b
817 hash_expr (Case _ b _) = hashId b
818 hash_expr (App f e) = hash_expr f * fast_hash_expr e
819 hash_expr (Var v) = hashId v
820 hash_expr (Lit lit) = hashLiteral lit
821 hash_expr (Lam b _) = hashId b
822 hash_expr (Type t) = trace "hash_expr: type" 1 -- Shouldn't happen
824 fast_hash_expr (Var v) = hashId v
825 fast_hash_expr (Lit lit) = hashLiteral lit
826 fast_hash_expr (App f (Type _)) = fast_hash_expr f
827 fast_hash_expr (App f a) = fast_hash_expr a
828 fast_hash_expr (Lam b _) = hashId b
829 fast_hash_expr other = 1
832 hashId id = hashName (idName id)