2 % (c) The AQUA Project, Glasgow University, 1994-1998
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 @getUnique@ method to grab their @Uniques@.
11 (A similar thing to @UniqSet@, as opposed to @Set@.)
15 UniqFM, -- abstract type
23 addListToUFM,addListToUFM_C,
25 addListToUFM_Directly,
41 lookupUFM, lookupUFM_Directly,
42 lookupWithDefaultUFM, lookupWithDefaultUFM_Directly,
47 #include "HsVersions.h"
49 import {-# SOURCE #-} Name ( Name )
51 import Unique ( Uniquable(..), Unique, u2i, mkUniqueGrimily )
53 import GlaExts -- Lots of Int# operations
56 #if ! OMIT_NATIVE_CODEGEN
59 #define IF_NCG(a) {--}
63 %************************************************************************
65 \subsection{The @UniqFM@ type, and signatures for the functions}
67 %************************************************************************
69 We use @FiniteMaps@, with a (@getUnique@-able) @Unique@ as ``key''.
72 emptyUFM :: UniqFM elt
73 isNullUFM :: UniqFM elt -> Bool
74 unitUFM :: Uniquable key => key -> elt -> UniqFM elt
75 unitDirectlyUFM -- got the Unique already
76 :: Unique -> elt -> UniqFM elt
77 listToUFM :: Uniquable key => [(key,elt)] -> UniqFM elt
79 :: [(Unique, elt)] -> UniqFM elt
81 addToUFM :: Uniquable key => UniqFM elt -> key -> elt -> UniqFM elt
82 addListToUFM :: Uniquable key => UniqFM elt -> [(key,elt)] -> UniqFM elt
84 :: UniqFM elt -> Unique -> elt -> UniqFM elt
86 addToUFM_C :: Uniquable key => (elt -> elt -> elt) -- old -> new -> result
89 -> UniqFM elt -- result
91 addListToUFM_C :: Uniquable key => (elt -> elt -> elt)
92 -> UniqFM elt -> [(key,elt)]
95 delFromUFM :: Uniquable key => UniqFM elt -> key -> UniqFM elt
96 delListFromUFM :: Uniquable key => UniqFM elt -> [key] -> UniqFM elt
97 delFromUFM_Directly :: UniqFM elt -> Unique -> UniqFM elt
99 plusUFM :: UniqFM elt -> UniqFM elt -> UniqFM elt
101 plusUFM_C :: (elt -> elt -> elt)
102 -> UniqFM elt -> UniqFM elt -> UniqFM elt
104 minusUFM :: UniqFM elt -> UniqFM elt -> UniqFM elt
106 intersectUFM :: UniqFM elt -> UniqFM elt -> UniqFM elt
107 intersectUFM_C :: (elt -> elt -> elt)
108 -> UniqFM elt -> UniqFM elt -> UniqFM elt
109 foldUFM :: (elt -> a -> a) -> a -> UniqFM elt -> a
110 mapUFM :: (elt1 -> elt2) -> UniqFM elt1 -> UniqFM elt2
111 filterUFM :: (elt -> Bool) -> UniqFM elt -> UniqFM elt
113 sizeUFM :: UniqFM elt -> Int
114 hashUFM :: UniqFM elt -> Int
115 elemUFM :: Uniquable key => key -> UniqFM elt -> Bool
117 lookupUFM :: Uniquable key => UniqFM elt -> key -> Maybe elt
118 lookupUFM_Directly -- when you've got the Unique already
119 :: UniqFM elt -> Unique -> Maybe elt
121 :: Uniquable key => UniqFM elt -> elt -> key -> elt
122 lookupWithDefaultUFM_Directly
123 :: UniqFM elt -> elt -> Unique -> elt
125 keysUFM :: UniqFM elt -> [Int] -- Get the keys
126 eltsUFM :: UniqFM elt -> [elt]
127 ufmToList :: UniqFM elt -> [(Unique, elt)]
130 %************************************************************************
132 \subsection{The @IdFinMap@ and @TyVarFinMap@ specialisations for Ids/TyVars}
134 %************************************************************************
137 -- Turn off for now, these need to be updated (SDM 4/98)
140 #ifdef __GLASGOW_HASKELL__
141 -- I don't think HBC was too happy about this (WDP 94/10)
144 addListToUFM :: UniqFM elt -> [(Name, elt)] -> UniqFM elt
147 addListToUFM_C :: (elt -> elt -> elt) -> UniqFM elt -> [(Name, elt)] -> UniqFM elt
150 addToUFM :: UniqFM elt -> Unique -> elt -> UniqFM elt
153 listToUFM :: [(Unique, elt)] -> UniqFM elt
156 lookupUFM :: UniqFM elt -> Name -> Maybe elt
157 , UniqFM elt -> Unique -> Maybe elt
160 #endif {- __GLASGOW_HASKELL__ -}
164 %************************************************************************
166 \subsection{Andy Gill's underlying @UniqFM@ machinery}
168 %************************************************************************
170 ``Uniq Finite maps'' are the heart and soul of the compiler's
171 lookup-tables/environments. Important stuff! It works well with
172 Dense and Sparse ranges.
173 Both @Uq@ Finite maps and @Hash@ Finite Maps
174 are built ontop of Int Finite Maps.
176 This code is explained in the paper:
178 A Gill, S Peyton Jones, B O'Sullivan, W Partain and Aqua Friends
179 "A Cheap balancing act that grows on a tree"
180 Glasgow FP Workshop, Sep 1994, pp??-??
183 %************************************************************************
185 \subsubsection{The @UniqFM@ type, and signatures for the functions}
187 %************************************************************************
189 @UniqFM a@ is a mapping from Unique to a.
191 First, the DataType itself; which is either a Node, a Leaf, or an Empty.
196 | LeafUFM FAST_INT ele
197 | NodeUFM FAST_INT -- the switching
198 FAST_INT -- the delta
203 -- for debugging only :-)
204 instance Outputable (UniqFM a) where
205 ppr(NodeUFM a b t1 t2) =
206 sep [text "NodeUFM " <+> int IBOX(a) <+> int IBOX(b),
207 nest 1 (parens (ppr t1)),
208 nest 1 (parens (ppr t2))]
209 ppr (LeafUFM x a) = text "LeafUFM " <+> int IBOX(x)
210 ppr (EmptyUFM) = empty
214 %************************************************************************
216 \subsubsection{The @UniqFM@ functions}
218 %************************************************************************
220 First the ways of building a UniqFM.
224 unitUFM key elt = mkLeafUFM (u2i (getUnique key)) elt
225 unitDirectlyUFM key elt = mkLeafUFM (u2i key) elt
227 listToUFM key_elt_pairs
228 = addListToUFM_C use_snd EmptyUFM key_elt_pairs
230 listToUFM_Directly uniq_elt_pairs
231 = addListToUFM_directly_C use_snd EmptyUFM uniq_elt_pairs
234 Now ways of adding things to UniqFMs.
236 There is an alternative version of @addListToUFM_C@, that uses @plusUFM@,
237 but the semantics of this operation demands a linear insertion;
238 perhaps the version without the combinator function
239 could be optimised using it.
242 addToUFM fm key elt = addToUFM_C use_snd fm key elt
244 addToUFM_Directly fm u elt = insert_ele use_snd fm (u2i u) elt
246 addToUFM_C combiner fm key elt
247 = insert_ele combiner fm (u2i (getUnique key)) elt
249 addListToUFM fm key_elt_pairs = addListToUFM_C use_snd fm key_elt_pairs
250 addListToUFM_Directly fm uniq_elt_pairs = addListToUFM_directly_C use_snd fm uniq_elt_pairs
252 addListToUFM_C combiner fm key_elt_pairs
253 = foldl (\ fm (k, e) -> insert_ele combiner fm (u2i (getUnique k)) e)
256 addListToUFM_directly_C combiner fm uniq_elt_pairs
257 = foldl (\ fm (k, e) -> insert_ele combiner fm (u2i k) e)
261 Now ways of removing things from UniqFM.
264 delListFromUFM fm lst = foldl delFromUFM fm lst
266 delFromUFM fm key = delete fm (u2i (getUnique key))
267 delFromUFM_Directly fm u = delete fm (u2i u)
269 delete EmptyUFM _ = EmptyUFM
270 delete fm key = del_ele fm
272 del_ele :: UniqFM a -> UniqFM a
274 del_ele lf@(LeafUFM j _)
275 | j _EQ_ key = EmptyUFM
276 | otherwise = lf -- no delete!
278 del_ele nd@(NodeUFM j p t1 t2)
280 = mkSLNodeUFM (NodeUFMData j p) (del_ele t1) t2
282 = mkLSNodeUFM (NodeUFMData j p) t1 (del_ele t2)
284 del_ele _ = panic "Found EmptyUFM FM when rec-deleting"
287 Now ways of adding two UniqFM's together.
290 plusUFM tr1 tr2 = plusUFM_C use_snd tr1 tr2
292 plusUFM_C f EmptyUFM tr = tr
293 plusUFM_C f tr EmptyUFM = tr
294 plusUFM_C f fm1 fm2 = mix_trees fm1 fm2
296 mix_trees (LeafUFM i a) t2 = insert_ele (flip f) t2 i a
297 mix_trees t1 (LeafUFM i a) = insert_ele f t1 i a
299 mix_trees left_t@(NodeUFM j p t1 t2) right_t@(NodeUFM j' p' t1' t2')
301 (ask_about_common_ancestor
305 -- Given a disjoint j,j' (p >^ p' && p' >^ p):
309 -- t1 t2 t1' t2' j j'
314 mix_branches (NewRoot nd False)
315 = mkLLNodeUFM nd left_t right_t
316 mix_branches (NewRoot nd True)
317 = mkLLNodeUFM nd right_t left_t
323 -- t1 t2 t1' t2' t1 + t1' t2 + t2'
325 mix_branches (SameRoot)
326 = mkSSNodeUFM (NodeUFMData j p)
329 -- Now the 4 different other ways; all like this:
331 -- Given j >^ j' (and, say, j > j')
335 -- t1 t2 t1' t2' t1 t2 + j'
338 mix_branches (LeftRoot Leftt) -- | trace "LL" True
341 (mix_trees t1 right_t)
344 mix_branches (LeftRoot Rightt) -- | trace "LR" True
348 (mix_trees t2 right_t)
350 mix_branches (RightRoot Leftt) -- | trace "RL" True
353 (mix_trees left_t t1')
356 mix_branches (RightRoot Rightt) -- | trace "RR" True
360 (mix_trees left_t t2')
362 mix_trees _ _ = panic "EmptyUFM found when inserting into plusInt"
365 And ways of subtracting them. First the base cases,
366 then the full D&C approach.
369 minusUFM EmptyUFM _ = EmptyUFM
370 minusUFM t1 EmptyUFM = t1
371 minusUFM fm1 fm2 = minus_trees fm1 fm2
374 -- Notice the asymetry of subtraction
376 minus_trees lf@(LeafUFM i a) t2 =
381 minus_trees t1 (LeafUFM i _) = delete t1 i
383 minus_trees left_t@(NodeUFM j p t1 t2) right_t@(NodeUFM j' p' t1' t2')
385 (ask_about_common_ancestor
389 -- Given a disjoint j,j' (p >^ p' && p' >^ p):
393 -- t1 t2 t1' t2' t1 t2
398 minus_branches (NewRoot nd _) = left_t
404 -- t1 t2 t1' t2' t1 + t1' t2 + t2'
406 minus_branches (SameRoot)
407 = mkSSNodeUFM (NodeUFMData j p)
410 -- Now the 4 different other ways; all like this:
411 -- again, with asymatry
414 -- The left is above the right
416 minus_branches (LeftRoot Leftt)
419 (minus_trees t1 right_t)
421 minus_branches (LeftRoot Rightt)
425 (minus_trees t2 right_t)
428 -- The right is above the left
430 minus_branches (RightRoot Leftt)
431 = minus_trees left_t t1'
432 minus_branches (RightRoot Rightt)
433 = minus_trees left_t t2'
435 minus_trees _ _ = panic "EmptyUFM found when insering into plusInt"
438 And taking the intersection of two UniqFM's.
441 intersectUFM t1 t2 = intersectUFM_C use_snd t1 t2
443 intersectUFM_C f EmptyUFM _ = EmptyUFM
444 intersectUFM_C f _ EmptyUFM = EmptyUFM
445 intersectUFM_C f fm1 fm2 = intersect_trees fm1 fm2
447 intersect_trees (LeafUFM i a) t2 =
450 Just b -> mkLeafUFM i (f a b)
452 intersect_trees t1 (LeafUFM i a) =
455 Just b -> mkLeafUFM i (f b a)
457 intersect_trees left_t@(NodeUFM j p t1 t2) right_t@(NodeUFM j' p' t1' t2')
459 (ask_about_common_ancestor
463 -- Given a disjoint j,j' (p >^ p' && p' >^ p):
466 -- / \ + / \ ==> EmptyUFM
471 intersect_branches (NewRoot nd _) = EmptyUFM
477 -- t1 t2 t1' t2' t1 x t1' t2 x t2'
479 intersect_branches (SameRoot)
480 = mkSSNodeUFM (NodeUFMData j p)
481 (intersect_trees t1 t1')
482 (intersect_trees t2 t2')
483 -- Now the 4 different other ways; all like this:
485 -- Given j >^ j' (and, say, j > j')
489 -- t1 t2 t1' t2' t1' t2'
491 -- This does cut down the search space quite a bit.
493 intersect_branches (LeftRoot Leftt)
494 = intersect_trees t1 right_t
495 intersect_branches (LeftRoot Rightt)
496 = intersect_trees t2 right_t
497 intersect_branches (RightRoot Leftt)
498 = intersect_trees left_t t1'
499 intersect_branches (RightRoot Rightt)
500 = intersect_trees left_t t2'
502 intersect_trees x y = panic ("EmptyUFM found when intersecting trees")
505 Now the usual set of `collection' operators, like map, fold, etc.
508 foldUFM f a (NodeUFM _ _ t1 t2) = foldUFM f (foldUFM f a t2) t1
509 foldUFM f a (LeafUFM _ obj) = f obj a
510 foldUFM f a EmptyUFM = a
514 mapUFM fn EmptyUFM = EmptyUFM
515 mapUFM fn fm = map_tree fn fm
517 filterUFM fn EmptyUFM = EmptyUFM
518 filterUFM fn fm = filter_tree fn fm
521 Note, this takes a long time, O(n), but
522 because we dont want to do this very often, we put up with this.
523 O'rable, but how often do we look at the size of
528 sizeUFM (NodeUFM _ _ t1 t2) = sizeUFM t1 + sizeUFM t2
529 sizeUFM (LeafUFM _ _) = 1
531 isNullUFM EmptyUFM = True
534 -- hashing is used in VarSet.uniqAway, and should be fast
535 -- We use a cheap and cheerful method for now
537 hashUFM (NodeUFM n _ _ _) = IBOX(n)
538 hashUFM (LeafUFM n _) = IBOX(n)
541 looking up in a hurry is the {\em whole point} of this binary tree lark.
542 Lookup up a binary tree is easy (and fast).
545 elemUFM key fm = case lookUp fm (u2i (getUnique key)) of
549 lookupUFM fm key = lookUp fm (u2i (getUnique key))
550 lookupUFM_Directly fm key = lookUp fm (u2i key)
552 lookupWithDefaultUFM fm deflt key
553 = case lookUp fm (u2i (getUnique key)) of
557 lookupWithDefaultUFM_Directly fm deflt key
558 = case lookUp fm (u2i key) of
562 lookUp EmptyUFM _ = Nothing
563 lookUp fm i = lookup_tree fm
565 lookup_tree :: UniqFM a -> Maybe a
567 lookup_tree (LeafUFM j b)
569 | otherwise = Nothing
570 lookup_tree (NodeUFM j p t1 t2)
571 | j _GT_ i = lookup_tree t1
572 | otherwise = lookup_tree t2
574 lookup_tree EmptyUFM = panic "lookup Failed"
577 folds are *wonderful* things.
580 eltsUFM fm = foldUFM (:) [] fm
582 ufmToList fm = fold_tree (\ iu elt rest -> (mkUniqueGrimily iu, elt) : rest) [] fm
584 keysUFM fm = fold_tree (\ iu elt rest -> IBOX(iu) : rest) [] fm
586 fold_tree f a (NodeUFM _ _ t1 t2) = fold_tree f (fold_tree f a t2) t1
587 fold_tree f a (LeafUFM iu obj) = f iu obj a
588 fold_tree f a EmptyUFM = a
591 %************************************************************************
593 \subsubsection{The @UniqFM@ type, and its functions}
595 %************************************************************************
597 You should always use these to build the tree.
598 There are 4 versions of mkNodeUFM, depending on
599 the strictness of the two sub-tree arguments.
600 The strictness is used *both* to prune out
601 empty trees, *and* to improve performance,
602 stoping needless thunks lying around.
603 The rule of thumb (from experence with these trees)
604 is make thunks strict, but data structures lazy.
605 If in doubt, use mkSSNodeUFM, which has the `strongest'
606 functionality, but may do a few needless evaluations.
609 mkLeafUFM :: FAST_INT -> a -> UniqFM a
610 mkLeafUFM i a = LeafUFM i a
612 -- The *ONLY* ways of building a NodeUFM.
614 mkSSNodeUFM (NodeUFMData j p) EmptyUFM t2 = t2
615 mkSSNodeUFM (NodeUFMData j p) t1 EmptyUFM = t1
616 mkSSNodeUFM (NodeUFMData j p) t1 t2
617 = ASSERT(correctNodeUFM (IBOX(j)) (IBOX(p)) t1 t2)
620 mkSLNodeUFM (NodeUFMData j p) EmptyUFM t2 = t2
621 mkSLNodeUFM (NodeUFMData j p) t1 t2
622 = ASSERT(correctNodeUFM (IBOX(j)) (IBOX(p)) t1 t2)
625 mkLSNodeUFM (NodeUFMData j p) t1 EmptyUFM = t1
626 mkLSNodeUFM (NodeUFMData j p) t1 t2
627 = ASSERT(correctNodeUFM (IBOX(j)) (IBOX(p)) t1 t2)
630 mkLLNodeUFM (NodeUFMData j p) t1 t2
631 = ASSERT(correctNodeUFM (IBOX(j)) (IBOX(p)) t1 t2)
641 correctNodeUFM j p t1 t2
642 = correct (j-p) (j-1) p t1 && correct j ((j-1)+p) p t2
644 correct low high _ (LeafUFM i _)
645 = low <= IBOX(i) && IBOX(i) <= high
646 correct low high above_p (NodeUFM j p _ _)
647 = low <= IBOX(j) && IBOX(j) <= high && above_p > IBOX(p)
648 correct _ _ _ EmptyUFM = panic "EmptyUFM stored inside a tree"
651 Note: doing SAT on this by hand seems to make it worse. Todo: Investigate,
652 and if necessary do $\lambda$ lifting on our functions that are bound.
662 insert_ele f EmptyUFM i new = mkLeafUFM i new
664 insert_ele f (LeafUFM j old) i new
666 mkLLNodeUFM (getCommonNodeUFMData
671 | j _EQ_ i = mkLeafUFM j (f old new)
673 mkLLNodeUFM (getCommonNodeUFMData
679 insert_ele f n@(NodeUFM j p t1 t2) i a
681 = if (i _GE_ (j _SUB_ p))
682 then mkSLNodeUFM (NodeUFMData j p) (insert_ele f t1 i a) t2
683 else mkLLNodeUFM (getCommonNodeUFMData
689 = if (i _LE_ ((j _SUB_ ILIT(1)) _ADD_ p))
690 then mkLSNodeUFM (NodeUFMData j p) t1 (insert_ele f t2 i a)
691 else mkLLNodeUFM (getCommonNodeUFMData
701 map_tree f (NodeUFM j p t1 t2)
702 = mkSSNodeUFM (NodeUFMData j p) (map_tree f t1) (map_tree f t2)
703 map_tree f (LeafUFM i obj)
704 = mkLeafUFM i (f obj)
706 map_tree f _ = panic "map_tree failed"
710 filter_tree f nd@(NodeUFM j p t1 t2)
711 = mkSSNodeUFM (NodeUFMData j p) (filter_tree f t1) (filter_tree f t2)
713 filter_tree f lf@(LeafUFM i obj)
715 | otherwise = EmptyUFM
716 filter_tree f _ = panic "filter_tree failed"
719 %************************************************************************
721 \subsubsection{The @UniqFM@ type, and signatures for the functions}
723 %************************************************************************
727 This is the information that is held inside a NodeUFM, packaged up for
732 = NodeUFMData FAST_INT
736 This is the information used when computing new NodeUFMs.
739 data Side = Leftt | Rightt -- NB: avoid 1.3 names "Left" and "Right"
741 = LeftRoot Side -- which side is the right down ?
742 | RightRoot Side -- which side is the left down ?
743 | SameRoot -- they are the same !
744 | NewRoot NodeUFMData -- here's the new, common, root
745 Bool -- do you need to swap left and right ?
748 This specifies the relationship between NodeUFMData and CalcNodeUFMData.
751 indexToRoot :: FAST_INT -> NodeUFMData
755 l = (ILIT(1) :: FAST_INT)
757 NodeUFMData (((i `shiftR_` l) `shiftL_` l) _ADD_ ILIT(1)) l
759 getCommonNodeUFMData :: NodeUFMData -> NodeUFMData -> NodeUFMData
761 getCommonNodeUFMData (NodeUFMData i p) (NodeUFMData i2 p2)
762 | p _EQ_ p2 = getCommonNodeUFMData_ p j j2
763 | p _LT_ p2 = getCommonNodeUFMData_ p2 (j _QUOT_ (p2 _QUOT_ p)) j2
764 | otherwise = getCommonNodeUFMData_ p j (j2 _QUOT_ (p _QUOT_ p2))
766 l = (ILIT(1) :: FAST_INT)
767 j = i _QUOT_ (p `shiftL_` l)
768 j2 = i2 _QUOT_ (p2 `shiftL_` l)
770 getCommonNodeUFMData_ :: FAST_INT -> FAST_INT -> FAST_INT -> NodeUFMData
772 getCommonNodeUFMData_ p j j_
774 = NodeUFMData (((j `shiftL_` l) _ADD_ l) _MUL_ p) p
776 = getCommonNodeUFMData_ (p `shiftL_` l) (j `shiftR_` l) (j_ `shiftR_` l)
778 ask_about_common_ancestor :: NodeUFMData -> NodeUFMData -> CommonRoot
780 ask_about_common_ancestor x@(NodeUFMData j p) y@(NodeUFMData j2 p2)
781 | j _EQ_ j2 = SameRoot
783 = case getCommonNodeUFMData x y of
784 nd@(NodeUFMData j3 p3)
785 | j3 _EQ_ j -> LeftRoot (decideSide (j _GT_ j2))
786 | j3 _EQ_ j2 -> RightRoot (decideSide (j _LT_ j2))
787 | otherwise -> NewRoot nd (j _GT_ j2)
789 decideSide :: Bool -> Side
790 decideSide True = Leftt
791 decideSide False = Rightt
794 This might be better in Util.lhs ?
797 Now the bit twiddling functions.
799 shiftL_ :: FAST_INT -> FAST_INT -> FAST_INT
800 shiftR_ :: FAST_INT -> FAST_INT -> FAST_INT
802 #if __GLASGOW_HASKELL__
803 {-# INLINE shiftL_ #-}
804 {-# INLINE shiftR_ #-}
805 shiftL_ n p = word2Int#((int2Word# n) `shiftL#` p)
806 shiftR_ n p = word2Int#((int2Word# n) `shiftr` p)
808 shiftr x y = shiftRL# x y
811 shiftL_ n p = n * (2 ^ p)
812 shiftR_ n p = n `quot` (2 ^ p)
818 use_snd :: a -> b -> b