2 % (c) The AQUA Project, Glasgow University, 1994-1996
4 \section[UniqFM]{Specialised finite maps, for things with @Uniques@}
6 Based on @FiniteMaps@ (as you would expect).
8 Basically, the things need to be in class @Uniquable@, and we use the
9 @uniqueOf@ method to grab their @Uniques@.
11 (A similar thing to @UniqSet@, as opposed to @Set@.)
14 #include "HsVersions.h"
17 UniqFM, -- abstract type
25 addListToUFM,addListToUFM_C,
27 addListToUFM_Directly,
41 lookupUFM, lookupUFM_Directly,
42 lookupWithDefaultUFM, lookupWithDefaultUFM_Directly,
50 #if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ <= 201
51 IMPORT_DELOOPER( SpecLoop )
53 import {-# SOURCE #-} Name
56 import Unique ( Uniquable(..), Unique, u2i, mkUniqueGrimily )
59 import Outputable ( PprStyle, Outputable(..) )
60 import SrcLoc ( SrcLoc )
62 #if ! OMIT_NATIVE_CODEGEN
65 #define IF_NCG(a) {--}
69 %************************************************************************
71 \subsection{The @UniqFM@ type, and signatures for the functions}
73 %************************************************************************
75 We use @FiniteMaps@, with a (@uniqueOf@-able) @Unique@ as ``key''.
78 emptyUFM :: UniqFM elt
79 isNullUFM :: UniqFM elt -> Bool
80 unitUFM :: Uniquable key => key -> elt -> UniqFM elt
81 unitDirectlyUFM -- got the Unique already
82 :: Unique -> elt -> UniqFM elt
83 listToUFM :: Uniquable key => [(key,elt)] -> UniqFM elt
85 :: [(Unique, elt)] -> UniqFM elt
87 addToUFM :: Uniquable key => UniqFM elt -> key -> elt -> UniqFM elt
88 addListToUFM :: Uniquable key => UniqFM elt -> [(key,elt)] -> UniqFM elt
90 :: UniqFM elt -> Unique -> elt -> UniqFM elt
92 addToUFM_C :: Uniquable key => (elt -> elt -> elt)
93 -> UniqFM elt -> key -> elt -> UniqFM elt
94 addListToUFM_C :: Uniquable key => (elt -> elt -> elt)
95 -> UniqFM elt -> [(key,elt)]
98 delFromUFM :: Uniquable key => UniqFM elt -> key -> UniqFM elt
99 delListFromUFM :: Uniquable key => UniqFM elt -> [key] -> UniqFM elt
100 delFromUFM_Directly :: UniqFM elt -> Unique -> UniqFM elt
102 plusUFM :: UniqFM elt -> UniqFM elt -> UniqFM elt
104 plusUFM_C :: (elt -> elt -> elt)
105 -> UniqFM elt -> UniqFM elt -> UniqFM elt
107 minusUFM :: UniqFM elt -> UniqFM elt -> UniqFM elt
109 intersectUFM :: UniqFM elt -> UniqFM elt -> UniqFM elt
110 intersectUFM_C :: (elt -> elt -> elt)
111 -> UniqFM elt -> UniqFM elt -> UniqFM elt
112 foldUFM :: (elt -> a -> a) -> a -> UniqFM elt -> a
113 mapUFM :: (elt1 -> elt2) -> UniqFM elt1 -> UniqFM elt2
114 filterUFM :: (elt -> Bool) -> UniqFM elt -> UniqFM elt
116 sizeUFM :: UniqFM elt -> Int
118 lookupUFM :: Uniquable key => UniqFM elt -> key -> Maybe elt
119 lookupUFM_Directly -- when you've got the Unique already
120 :: UniqFM elt -> Unique -> Maybe elt
122 :: Uniquable key => UniqFM elt -> elt -> key -> elt
123 lookupWithDefaultUFM_Directly
124 :: UniqFM elt -> elt -> Unique -> elt
126 keysUFM :: UniqFM elt -> [Int] -- Get the keys
127 eltsUFM :: UniqFM elt -> [elt]
128 ufmToList :: UniqFM elt -> [(Unique, elt)]
131 %************************************************************************
133 \subsection{The @IdFinMap@ and @TyVarFinMap@ specialisations for Ids/TyVars}
135 %************************************************************************
138 #ifdef __GLASGOW_HASKELL__
139 -- I don't think HBC was too happy about this (WDP 94/10)
142 addListToUFM :: UniqFM elt -> [(Name, elt)] -> UniqFM elt
145 addListToUFM_C :: (elt -> elt -> elt) -> UniqFM elt -> [(Name, elt)] -> UniqFM elt
148 addToUFM :: UniqFM elt -> Unique -> elt -> UniqFM elt
151 listToUFM :: [(Unique, elt)] -> UniqFM elt
154 lookupUFM :: UniqFM elt -> Name -> Maybe elt
155 , UniqFM elt -> Unique -> Maybe elt
158 #endif {- __GLASGOW_HASKELL__ -}
161 %************************************************************************
163 \subsection{Andy Gill's underlying @UniqFM@ machinery}
165 %************************************************************************
167 ``Uniq Finite maps'' are the heart and soul of the compiler's
168 lookup-tables/environments. Important stuff! It works well with
169 Dense and Sparse ranges.
170 Both @Uq@ Finite maps and @Hash@ Finite Maps
171 are built ontop of Int Finite Maps.
173 This code is explained in the paper:
175 A Gill, S Peyton Jones, B O'Sullivan, W Partain and Aqua Friends
176 "A Cheap balancing act that grows on a tree"
177 Glasgow FP Workshop, Sep 1994, pp??-??
180 %************************************************************************
182 \subsubsection{The @UniqFM@ type, and signatures for the functions}
184 %************************************************************************
186 @UniqFM a@ is a mapping from Unique to a.
188 First, the DataType itself; which is either a Node, a Leaf, or an Empty.
193 | LeafUFM FAST_INT ele
194 | NodeUFM FAST_INT -- the switching
195 FAST_INT -- the delta
199 -- for debugging only :-)
201 instance Text (UniqFM a) where
202 showsPrec _ (NodeUFM a b t1 t2) =
203 showString "NodeUFM " . shows (IBOX(a))
204 . showString " " . shows (IBOX(b))
205 . showString " (" . shows t1
206 . showString ") (" . shows t2
208 showsPrec _ (LeafUFM x a) = showString "LeafUFM " . shows (IBOX(x))
209 showsPrec _ (EmptyUFM) = id
213 %************************************************************************
215 \subsubsection{The @UniqFM@ functions}
217 %************************************************************************
219 First the ways of building a UniqFM.
223 unitUFM key elt = mkLeafUFM (u2i (uniqueOf key)) elt
224 unitDirectlyUFM key elt = mkLeafUFM (u2i key) elt
226 listToUFM key_elt_pairs
227 = addListToUFM_C use_snd EmptyUFM key_elt_pairs
229 listToUFM_Directly uniq_elt_pairs
230 = addListToUFM_directly_C use_snd EmptyUFM uniq_elt_pairs
233 Now ways of adding things to UniqFMs.
235 There is an alternative version of @addListToUFM_C@, that uses @plusUFM@,
236 but the semantics of this operation demands a linear insertion;
237 perhaps the version without the combinator function
238 could be optimised using it.
241 addToUFM fm key elt = addToUFM_C use_snd fm key elt
243 addToUFM_Directly fm u elt = insert_ele use_snd fm (u2i u) elt
245 addToUFM_C combiner fm key elt
246 = insert_ele combiner fm (u2i (uniqueOf key)) elt
248 addListToUFM fm key_elt_pairs = addListToUFM_C use_snd fm key_elt_pairs
249 addListToUFM_Directly fm uniq_elt_pairs = addListToUFM_directly_C use_snd fm uniq_elt_pairs
251 addListToUFM_C combiner fm key_elt_pairs
252 = foldl (\ fm (k, e) -> insert_ele combiner fm (u2i (uniqueOf k)) e)
255 addListToUFM_directly_C combiner fm uniq_elt_pairs
256 = foldl (\ fm (k, e) -> insert_ele combiner fm (u2i k) e)
260 Now ways of removing things from UniqFM.
263 delListFromUFM fm lst = foldl delFromUFM fm lst
265 delFromUFM fm key = delete fm (u2i (uniqueOf key))
266 delFromUFM_Directly fm u = delete fm (u2i u)
268 delete EmptyUFM _ = EmptyUFM
269 delete fm key = del_ele fm
271 del_ele :: UniqFM a -> UniqFM a
273 del_ele lf@(LeafUFM j _)
274 | j _EQ_ key = EmptyUFM
275 | otherwise = lf -- no delete!
277 del_ele nd@(NodeUFM j p t1 t2)
279 = mkSLNodeUFM (NodeUFMData j p) (del_ele t1) t2
281 = mkLSNodeUFM (NodeUFMData j p) t1 (del_ele t2)
283 del_ele _ = panic "Found EmptyUFM FM when rec-deleting"
286 Now ways of adding two UniqFM's together.
289 plusUFM tr1 tr2 = plusUFM_C use_snd tr1 tr2
291 plusUFM_C f EmptyUFM tr = tr
292 plusUFM_C f tr EmptyUFM = tr
293 plusUFM_C f fm1 fm2 = mix_trees fm1 fm2
295 mix_trees (LeafUFM i a) t2 = insert_ele (flip f) t2 i a
296 mix_trees t1 (LeafUFM i a) = insert_ele f t1 i a
298 mix_trees left_t@(NodeUFM j p t1 t2) right_t@(NodeUFM j' p' t1' t2')
300 (ask_about_common_ancestor
304 -- Given a disjoint j,j' (p >^ p' && p' >^ p):
308 -- t1 t2 t1' t2' j j'
313 mix_branches (NewRoot nd False)
314 = mkLLNodeUFM nd left_t right_t
315 mix_branches (NewRoot nd True)
316 = mkLLNodeUFM nd right_t left_t
322 -- t1 t2 t1' t2' t1 + t1' t2 + t2'
324 mix_branches (SameRoot)
325 = mkSSNodeUFM (NodeUFMData j p)
328 -- Now the 4 different other ways; all like this:
330 -- Given j >^ j' (and, say, j > j')
334 -- t1 t2 t1' t2' t1 t2 + j'
337 mix_branches (LeftRoot Leftt) -- | trace "LL" True
340 (mix_trees t1 right_t)
343 mix_branches (LeftRoot Rightt) -- | trace "LR" True
347 (mix_trees t2 right_t)
349 mix_branches (RightRoot Leftt) -- | trace "RL" True
352 (mix_trees left_t t1')
355 mix_branches (RightRoot Rightt) -- | trace "RR" True
359 (mix_trees left_t t2')
361 mix_trees _ _ = panic "EmptyUFM found when inserting into plusInt"
364 And ways of subtracting them. First the base cases,
365 then the full D&C approach.
368 minusUFM EmptyUFM _ = EmptyUFM
369 minusUFM t1 EmptyUFM = t1
370 minusUFM fm1 fm2 = minus_trees fm1 fm2
373 -- Notice the asymetry of subtraction
375 minus_trees lf@(LeafUFM i a) t2 =
380 minus_trees t1 (LeafUFM i _) = delete t1 i
382 minus_trees left_t@(NodeUFM j p t1 t2) right_t@(NodeUFM j' p' t1' t2')
384 (ask_about_common_ancestor
388 -- Given a disjoint j,j' (p >^ p' && p' >^ p):
392 -- t1 t2 t1' t2' t1 t2
397 minus_branches (NewRoot nd _) = left_t
403 -- t1 t2 t1' t2' t1 + t1' t2 + t2'
405 minus_branches (SameRoot)
406 = mkSSNodeUFM (NodeUFMData j p)
409 -- Now the 4 different other ways; all like this:
410 -- again, with asymatry
413 -- The left is above the right
415 minus_branches (LeftRoot Leftt)
418 (minus_trees t1 right_t)
420 minus_branches (LeftRoot Rightt)
424 (minus_trees t2 right_t)
427 -- The right is above the left
429 minus_branches (RightRoot Leftt)
430 = minus_trees left_t t1'
431 minus_branches (RightRoot Rightt)
432 = minus_trees left_t t2'
434 minus_trees _ _ = panic "EmptyUFM found when insering into plusInt"
437 And taking the intersection of two UniqFM's.
440 intersectUFM t1 t2 = intersectUFM_C use_snd t1 t2
442 intersectUFM_C f EmptyUFM _ = EmptyUFM
443 intersectUFM_C f _ EmptyUFM = EmptyUFM
444 intersectUFM_C f fm1 fm2 = intersect_trees fm1 fm2
446 intersect_trees (LeafUFM i a) t2 =
449 Just b -> mkLeafUFM i (f a b)
451 intersect_trees t1 (LeafUFM i a) =
454 Just b -> mkLeafUFM i (f b a)
456 intersect_trees left_t@(NodeUFM j p t1 t2) right_t@(NodeUFM j' p' t1' t2')
458 (ask_about_common_ancestor
462 -- Given a disjoint j,j' (p >^ p' && p' >^ p):
465 -- / \ + / \ ==> EmptyUFM
470 intersect_branches (NewRoot nd _) = EmptyUFM
476 -- t1 t2 t1' t2' t1 x t1' t2 x t2'
478 intersect_branches (SameRoot)
479 = mkSSNodeUFM (NodeUFMData j p)
480 (intersect_trees t1 t1')
481 (intersect_trees t2 t2')
482 -- Now the 4 different other ways; all like this:
484 -- Given j >^ j' (and, say, j > j')
488 -- t1 t2 t1' t2' t1' t2'
490 -- This does cut down the search space quite a bit.
492 intersect_branches (LeftRoot Leftt)
493 = intersect_trees t1 right_t
494 intersect_branches (LeftRoot Rightt)
495 = intersect_trees t2 right_t
496 intersect_branches (RightRoot Leftt)
497 = intersect_trees left_t t1'
498 intersect_branches (RightRoot Rightt)
499 = intersect_trees left_t t2'
501 intersect_trees x y = panic ("EmptyUFM found when intersecting trees")
504 Now the usual set of `collection' operators, like map, fold, etc.
507 foldUFM f a (NodeUFM _ _ t1 t2) = foldUFM f (foldUFM f a t2) t1
508 foldUFM f a (LeafUFM _ obj) = f obj a
509 foldUFM f a EmptyUFM = a
513 mapUFM fn EmptyUFM = EmptyUFM
514 mapUFM fn fm = map_tree fn fm
516 filterUFM fn EmptyUFM = EmptyUFM
517 filterUFM fn fm = filter_tree fn fm
520 Note, this takes a long time, O(n), but
521 because we dont want to do this very often, we put up with this.
522 O'rable, but how often do we look at the size of
527 sizeUFM (NodeUFM _ _ t1 t2) = sizeUFM t1 + sizeUFM t2
528 sizeUFM (LeafUFM _ _) = 1
530 isNullUFM EmptyUFM = True
534 looking up in a hurry is the {\em whole point} of this binary tree lark.
535 Lookup up a binary tree is easy (and fast).
538 lookupUFM fm key = lookUp fm (u2i (uniqueOf key))
539 lookupUFM_Directly fm key = lookUp fm (u2i key)
541 lookupWithDefaultUFM fm deflt key
542 = case lookUp fm (u2i (uniqueOf key)) of
546 lookupWithDefaultUFM_Directly fm deflt key
547 = case lookUp fm (u2i key) of
551 lookUp EmptyUFM _ = Nothing
552 lookUp fm i = lookup_tree fm
554 lookup_tree :: UniqFM a -> Maybe a
556 lookup_tree (LeafUFM j b)
558 | otherwise = Nothing
559 lookup_tree (NodeUFM j p t1 t2)
560 | j _GT_ i = lookup_tree t1
561 | otherwise = lookup_tree t2
563 lookup_tree EmptyUFM = panic "lookup Failed"
566 folds are *wonderful* things.
569 eltsUFM fm = foldUFM (:) [] fm
571 ufmToList fm = fold_tree (\ iu elt rest -> (mkUniqueGrimily iu, elt) : rest) [] fm
573 keysUFM fm = fold_tree (\ iu elt rest -> IBOX(iu) : rest) [] fm
575 fold_tree f a (NodeUFM _ _ t1 t2) = fold_tree f (fold_tree f a t2) t1
576 fold_tree f a (LeafUFM iu obj) = f iu obj a
577 fold_tree f a EmptyUFM = a
580 %************************************************************************
582 \subsubsection{The @UniqFM@ type, and its functions}
584 %************************************************************************
586 You should always use these to build the tree.
587 There are 4 versions of mkNodeUFM, depending on
588 the strictness of the two sub-tree arguments.
589 The strictness is used *both* to prune out
590 empty trees, *and* to improve performance,
591 stoping needless thunks lying around.
592 The rule of thumb (from experence with these trees)
593 is make thunks strict, but data structures lazy.
594 If in doubt, use mkSSNodeUFM, which has the `strongest'
595 functionality, but may do a few needless evaluations.
598 mkLeafUFM :: FAST_INT -> a -> UniqFM a
599 mkLeafUFM i a = LeafUFM i a
601 -- The *ONLY* ways of building a NodeUFM.
603 mkSSNodeUFM (NodeUFMData j p) EmptyUFM t2 = t2
604 mkSSNodeUFM (NodeUFMData j p) t1 EmptyUFM = t1
605 mkSSNodeUFM (NodeUFMData j p) t1 t2
606 = ASSERT(correctNodeUFM (IBOX(j)) (IBOX(p)) t1 t2)
609 mkSLNodeUFM (NodeUFMData j p) EmptyUFM t2 = t2
610 mkSLNodeUFM (NodeUFMData j p) t1 t2
611 = ASSERT(correctNodeUFM (IBOX(j)) (IBOX(p)) t1 t2)
614 mkLSNodeUFM (NodeUFMData j p) t1 EmptyUFM = t1
615 mkLSNodeUFM (NodeUFMData j p) t1 t2
616 = ASSERT(correctNodeUFM (IBOX(j)) (IBOX(p)) t1 t2)
619 mkLLNodeUFM (NodeUFMData j p) t1 t2
620 = ASSERT(correctNodeUFM (IBOX(j)) (IBOX(p)) t1 t2)
630 correctNodeUFM j p t1 t2
631 = correct (j-p) (j-1) p t1 && correct j ((j-1)+p) p t2
633 correct low high _ (LeafUFM i _)
634 = low <= IBOX(i) && IBOX(i) <= high
635 correct low high above_p (NodeUFM j p _ _)
636 = low <= IBOX(j) && IBOX(j) <= high && above_p > IBOX(p)
637 correct _ _ _ EmptyUFM = panic "EmptyUFM stored inside a tree"
640 Note: doing SAT on this by hand seems to make it worse. Todo: Investigate,
641 and if necessary do $\lambda$ lifting on our functions that are bound.
651 insert_ele f EmptyUFM i new = mkLeafUFM i new
653 insert_ele f (LeafUFM j old) i new
655 mkLLNodeUFM (getCommonNodeUFMData
660 | j _EQ_ i = mkLeafUFM j (f old new)
662 mkLLNodeUFM (getCommonNodeUFMData
668 insert_ele f n@(NodeUFM j p t1 t2) i a
670 = if (i _GE_ (j _SUB_ p))
671 then mkSLNodeUFM (NodeUFMData j p) (insert_ele f t1 i a) t2
672 else mkLLNodeUFM (getCommonNodeUFMData
678 = if (i _LE_ ((j _SUB_ ILIT(1)) _ADD_ p))
679 then mkLSNodeUFM (NodeUFMData j p) t1 (insert_ele f t2 i a)
680 else mkLLNodeUFM (getCommonNodeUFMData
690 map_tree f (NodeUFM j p t1 t2)
691 = mkSSNodeUFM (NodeUFMData j p) (map_tree f t1) (map_tree f t2)
692 map_tree f (LeafUFM i obj)
693 = mkLeafUFM i (f obj)
695 map_tree f _ = panic "map_tree failed"
699 filter_tree f nd@(NodeUFM j p t1 t2)
700 = mkSSNodeUFM (NodeUFMData j p) (filter_tree f t1) (filter_tree f t2)
702 filter_tree f lf@(LeafUFM i obj)
704 | otherwise = EmptyUFM
705 filter_tree f _ = panic "filter_tree failed"
708 %************************************************************************
710 \subsubsection{The @UniqFM@ type, and signatures for the functions}
712 %************************************************************************
716 This is the information that is held inside a NodeUFM, packaged up for
721 = NodeUFMData FAST_INT
725 This is the information used when computing new NodeUFMs.
728 data Side = Leftt | Rightt -- NB: avoid 1.3 names "Left" and "Right"
730 = LeftRoot Side -- which side is the right down ?
731 | RightRoot Side -- which side is the left down ?
732 | SameRoot -- they are the same !
733 | NewRoot NodeUFMData -- here's the new, common, root
734 Bool -- do you need to swap left and right ?
737 This specifies the relationship between NodeUFMData and CalcNodeUFMData.
740 indexToRoot :: FAST_INT -> NodeUFMData
744 l = (ILIT(1) :: FAST_INT)
746 NodeUFMData (((i `shiftR_` l) `shiftL_` l) _ADD_ ILIT(1)) l
748 getCommonNodeUFMData :: NodeUFMData -> NodeUFMData -> NodeUFMData
750 getCommonNodeUFMData (NodeUFMData i p) (NodeUFMData i2 p2)
751 | p _EQ_ p2 = getCommonNodeUFMData_ p j j2
752 | p _LT_ p2 = getCommonNodeUFMData_ p2 (j _QUOT_ (p2 _QUOT_ p)) j2
753 | otherwise = getCommonNodeUFMData_ p j (j2 _QUOT_ (p _QUOT_ p2))
755 l = (ILIT(1) :: FAST_INT)
756 j = i _QUOT_ (p `shiftL_` l)
757 j2 = i2 _QUOT_ (p2 `shiftL_` l)
759 getCommonNodeUFMData_ :: FAST_INT -> FAST_INT -> FAST_INT -> NodeUFMData
761 getCommonNodeUFMData_ p j j_
763 = NodeUFMData (((j `shiftL_` l) _ADD_ l) _MUL_ p) p
765 = getCommonNodeUFMData_ (p `shiftL_` l) (j `shiftR_` l) (j_ `shiftR_` l)
767 ask_about_common_ancestor :: NodeUFMData -> NodeUFMData -> CommonRoot
769 ask_about_common_ancestor x@(NodeUFMData j p) y@(NodeUFMData j2 p2)
770 | j _EQ_ j2 = SameRoot
772 = case getCommonNodeUFMData x y of
773 nd@(NodeUFMData j3 p3)
774 | j3 _EQ_ j -> LeftRoot (decideSide (j _GT_ j2))
775 | j3 _EQ_ j2 -> RightRoot (decideSide (j _LT_ j2))
776 | otherwise -> NewRoot nd (j _GT_ j2)
778 decideSide :: Bool -> Side
779 decideSide True = Leftt
780 decideSide False = Rightt
783 This might be better in Util.lhs ?
786 Now the bit twiddling functions.
788 shiftL_ :: FAST_INT -> FAST_INT -> FAST_INT
789 shiftR_ :: FAST_INT -> FAST_INT -> FAST_INT
791 #if __GLASGOW_HASKELL__
792 {-# INLINE shiftL_ #-}
793 {-# INLINE shiftR_ #-}
794 shiftL_ n p = word2Int#((int2Word# n) `shiftL#` p)
795 shiftR_ n p = word2Int#((int2Word# n) `shiftr` p)
797 shiftr x y = shiftRA# x y
800 shiftL_ n p = n * (2 ^ p)
801 shiftR_ n p = n `quot` (2 ^ p)
807 use_snd :: a -> b -> b