Line data Source code
1 : /* Functions to support general ended bitmaps.
2 : Copyright (C) 1997-2023 Free Software Foundation, Inc.
3 :
4 : This file is part of GCC.
5 :
6 : GCC is free software; you can redistribute it and/or modify it under
7 : the terms of the GNU General Public License as published by the Free
8 : Software Foundation; either version 3, or (at your option) any later
9 : version.
10 :
11 : GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 : WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 : FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 : for more details.
15 :
16 : You should have received a copy of the GNU General Public License
17 : along with GCC; see the file COPYING3. If not see
18 : <http://www.gnu.org/licenses/>. */
19 :
20 : #ifndef GCC_BITMAP_H
21 : #define GCC_BITMAP_H
22 :
23 : /* Implementation of sparse integer sets as a linked list or tree.
24 :
25 : This sparse set representation is suitable for sparse sets with an
26 : unknown (a priori) universe.
27 :
28 : Sets are represented as double-linked lists of container nodes of
29 : type "struct bitmap_element" or as a binary trees of the same
30 : container nodes. Each container node consists of an index for the
31 : first member that could be held in the container, a small array of
32 : integers that represent the members in the container, and pointers
33 : to the next and previous element in the linked list, or left and
34 : right children in the tree. In linked-list form, the container
35 : nodes in the list are sorted in ascending order, i.e. the head of
36 : the list holds the element with the smallest member of the set.
37 : In tree form, nodes to the left have a smaller container index.
38 :
39 : For a given member I in the set:
40 : - the element for I will have index is I / (bits per element)
41 : - the position for I within element is I % (bits per element)
42 :
43 : This representation is very space-efficient for large sparse sets, and
44 : the size of the set can be changed dynamically without much overhead.
45 : An important parameter is the number of bits per element. In this
46 : implementation, there are 128 bits per element. This results in a
47 : high storage overhead *per element*, but a small overall overhead if
48 : the set is very sparse.
49 :
50 : The storage requirements for linked-list sparse sets are O(E), with E->N
51 : in the worst case (a sparse set with large distances between the values
52 : of the set members).
53 :
54 : This representation also works well for data flow problems where the size
55 : of the set may grow dynamically, but care must be taken that the member_p,
56 : add_member, and remove_member operations occur with a suitable access
57 : pattern.
58 :
59 : The linked-list set representation works well for problems involving very
60 : sparse sets. The canonical example in GCC is, of course, the "set of
61 : sets" for some CFG-based data flow problems (liveness analysis, dominance
62 : frontiers, etc.).
63 :
64 : For random-access sparse sets of unknown universe, the binary tree
65 : representation is likely to be a more suitable choice. Theoretical
66 : access times for the binary tree representation are better than those
67 : for the linked-list, but in practice this is only true for truely
68 : random access.
69 :
70 : Often the most suitable representation during construction of the set
71 : is not the best choice for the usage of the set. For such cases, the
72 : "view" of the set can be changed from one representation to the other.
73 : This is an O(E) operation:
74 :
75 : * from list to tree view : bitmap_tree_view
76 : * from tree to list view : bitmap_list_view
77 :
78 : Traversing linked lists or trees can be cache-unfriendly. Performance
79 : can be improved by keeping container nodes in the set grouped together
80 : in memory, using a dedicated obstack for a set (or group of related
81 : sets). Elements allocated on obstacks are released to a free-list and
82 : taken off the free list. If multiple sets are allocated on the same
83 : obstack, elements freed from one set may be re-used for one of the other
84 : sets. This usually helps avoid cache misses.
85 :
86 : A single free-list is used for all sets allocated in GGC space. This is
87 : bad for persistent sets, so persistent sets should be allocated on an
88 : obstack whenever possible.
89 :
90 : For random-access sets with a known, relatively small universe size, the
91 : SparseSet or simple bitmap representations may be more efficient than a
92 : linked-list set.
93 :
94 :
95 : LINKED LIST FORM
96 : ================
97 :
98 : In linked-list form, in-order iterations of the set can be executed
99 : efficiently. The downside is that many random-access operations are
100 : relatively slow, because the linked list has to be traversed to test
101 : membership (i.e. member_p/ add_member/remove_member).
102 :
103 : To improve the performance of this set representation, the last
104 : accessed element and its index are cached. For membership tests on
105 : members close to recently accessed members, the cached last element
106 : improves membership test to a constant-time operation.
107 :
108 : The following operations can always be performed in O(1) time in
109 : list view:
110 :
111 : * clear : bitmap_clear
112 : * smallest_member : bitmap_first_set_bit
113 : * pop_smallest : bitmap_clear_first_set_bit
114 : * choose_one : (not implemented, but could be
115 : in constant time)
116 :
117 : The following operations can be performed in O(E) time worst-case in
118 : list view (with E the number of elements in the linked list), but in
119 : O(1) time with a suitable access patterns:
120 :
121 : * member_p : bitmap_bit_p
122 : * add_member : bitmap_set_bit / bitmap_set_range
123 : * remove_member : bitmap_clear_bit / bitmap_clear_range
124 :
125 : The following operations can be performed in O(E) time in list view:
126 :
127 : * cardinality : bitmap_count_bits
128 : * largest_member : bitmap_last_set_bit (but this could
129 : in constant time with a pointer to
130 : the last element in the chain)
131 : * set_size : bitmap_last_set_bit
132 :
133 : In tree view the following operations can all be performed in O(log E)
134 : amortized time with O(E) worst-case behavior.
135 :
136 : * smallest_member
137 : * pop_smallest
138 : * largest_member
139 : * set_size
140 : * member_p
141 : * add_member
142 : * remove_member
143 :
144 : Additionally, the linked-list sparse set representation supports
145 : enumeration of the members in O(E) time:
146 :
147 : * forall : EXECUTE_IF_SET_IN_BITMAP
148 : * set_copy : bitmap_copy
149 : * set_intersection : bitmap_intersect_p /
150 : bitmap_and / bitmap_and_into /
151 : EXECUTE_IF_AND_IN_BITMAP
152 : * set_union : bitmap_ior / bitmap_ior_into
153 : * set_difference : bitmap_intersect_compl_p /
154 : bitmap_and_comp / bitmap_and_comp_into /
155 : EXECUTE_IF_AND_COMPL_IN_BITMAP
156 : * set_disjuction : bitmap_xor_comp / bitmap_xor_comp_into
157 : * set_compare : bitmap_equal_p
158 :
159 : Some operations on 3 sets that occur frequently in data flow problems
160 : are also implemented:
161 :
162 : * A | (B & C) : bitmap_ior_and_into
163 : * A | (B & ~C) : bitmap_ior_and_compl /
164 : bitmap_ior_and_compl_into
165 :
166 :
167 : BINARY TREE FORM
168 : ================
169 : An alternate "view" of a bitmap is its binary tree representation.
170 : For this representation, splay trees are used because they can be
171 : implemented using the same data structures as the linked list, with
172 : no overhead for meta-data (like color, or rank) on the tree nodes.
173 :
174 : In binary tree form, random-access to the set is much more efficient
175 : than for the linked-list representation. Downsides are the high cost
176 : of clearing the set, and the relatively large number of operations
177 : necessary to balance the tree. Also, iterating the set members is
178 : not supported.
179 :
180 : As for the linked-list representation, the last accessed element and
181 : its index are cached, so that membership tests on the latest accessed
182 : members is a constant-time operation. Other lookups take O(logE)
183 : time amortized (but O(E) time worst-case).
184 :
185 : The following operations can always be performed in O(1) time:
186 :
187 : * choose_one : (not implemented, but could be
188 : implemented in constant time)
189 :
190 : The following operations can be performed in O(logE) time amortized
191 : but O(E) time worst-case, but in O(1) time if the same element is
192 : accessed.
193 :
194 : * member_p : bitmap_bit_p
195 : * add_member : bitmap_set_bit
196 : * remove_member : bitmap_clear_bit
197 :
198 : The following operations can be performed in O(logE) time amortized
199 : but O(E) time worst-case:
200 :
201 : * smallest_member : bitmap_first_set_bit
202 : * largest_member : bitmap_last_set_bit
203 : * set_size : bitmap_last_set_bit
204 :
205 : The following operations can be performed in O(E) time:
206 :
207 : * clear : bitmap_clear
208 :
209 : The binary tree sparse set representation does *not* support any form
210 : of enumeration, and does also *not* support logical operations on sets.
211 : The binary tree representation is only supposed to be used for sets
212 : on which many random-access membership tests will happen. */
213 :
214 : #include "obstack.h"
215 : #include "array-traits.h"
216 :
217 : /* Bitmap memory usage. */
218 : class bitmap_usage: public mem_usage
219 : {
220 : public:
221 : /* Default contructor. */
222 : bitmap_usage (): m_nsearches (0), m_search_iter (0) {}
223 : /* Constructor. */
224 : bitmap_usage (size_t allocated, size_t times, size_t peak,
225 : uint64_t nsearches, uint64_t search_iter)
226 : : mem_usage (allocated, times, peak),
227 : m_nsearches (nsearches), m_search_iter (search_iter) {}
228 :
229 : /* Sum the usage with SECOND usage. */
230 : bitmap_usage
231 : operator+ (const bitmap_usage &second)
232 : {
233 : return bitmap_usage (m_allocated + second.m_allocated,
234 : m_times + second.m_times,
235 : m_peak + second.m_peak,
236 : m_nsearches + second.m_nsearches,
237 : m_search_iter + second.m_search_iter);
238 : }
239 :
240 : /* Dump usage coupled to LOC location, where TOTAL is sum of all rows. */
241 : inline void
242 : dump (mem_location *loc, const mem_usage &total) const
243 : {
244 : char *location_string = loc->to_string ();
245 :
246 : fprintf (stderr, "%-48s " PRsa (9) ":%5.1f%%"
247 : PRsa (9) PRsa (9) ":%5.1f%%"
248 : PRsa (11) PRsa (11) "%10s\n",
249 : location_string, SIZE_AMOUNT (m_allocated),
250 : get_percent (m_allocated, total.m_allocated),
251 : SIZE_AMOUNT (m_peak), SIZE_AMOUNT (m_times),
252 : get_percent (m_times, total.m_times),
253 : SIZE_AMOUNT (m_nsearches), SIZE_AMOUNT (m_search_iter),
254 : loc->m_ggc ? "ggc" : "heap");
255 :
256 : free (location_string);
257 : }
258 :
259 : /* Dump header with NAME. */
260 : static inline void
261 : dump_header (const char *name)
262 : {
263 : fprintf (stderr, "%-48s %11s%16s%17s%12s%12s%10s\n", name, "Leak", "Peak",
264 : "Times", "N searches", "Search iter", "Type");
265 : }
266 :
267 : /* Number search operations. */
268 : uint64_t m_nsearches;
269 : /* Number of search iterations. */
270 : uint64_t m_search_iter;
271 : };
272 :
273 : /* Bitmap memory description. */
274 : extern mem_alloc_description<bitmap_usage> bitmap_mem_desc;
275 :
276 : /* Fundamental storage type for bitmap. */
277 :
278 : typedef unsigned long BITMAP_WORD;
279 : /* BITMAP_WORD_BITS needs to be unsigned, but cannot contain casts as
280 : it is used in preprocessor directives -- hence the 1u. */
281 : #define BITMAP_WORD_BITS (CHAR_BIT * SIZEOF_LONG * 1u)
282 :
283 : /* Number of words to use for each element in the linked list. */
284 :
285 : #ifndef BITMAP_ELEMENT_WORDS
286 : #define BITMAP_ELEMENT_WORDS ((128 + BITMAP_WORD_BITS - 1) / BITMAP_WORD_BITS)
287 : #endif
288 :
289 : /* Number of bits in each actual element of a bitmap. */
290 :
291 : #define BITMAP_ELEMENT_ALL_BITS (BITMAP_ELEMENT_WORDS * BITMAP_WORD_BITS)
292 :
293 : /* Obstack for allocating bitmaps and elements from. */
294 : struct bitmap_obstack {
295 : struct bitmap_element *elements;
296 : bitmap_head *heads;
297 : struct obstack obstack;
298 : };
299 :
300 : /* Bitmap set element. We use a linked list to hold only the bits that
301 : are set. This allows for use to grow the bitset dynamically without
302 : having to realloc and copy a giant bit array.
303 :
304 : The free list is implemented as a list of lists. There is one
305 : outer list connected together by prev fields. Each element of that
306 : outer is an inner list (that may consist only of the outer list
307 : element) that are connected by the next fields. The prev pointer
308 : is undefined for interior elements. This allows
309 : bitmap_elt_clear_from to be implemented in unit time rather than
310 : linear in the number of elements to be freed. */
311 :
312 : struct GTY((chain_next ("%h.next"))) bitmap_element {
313 : /* In list form, the next element in the linked list;
314 : in tree form, the left child node in the tree. */
315 : struct bitmap_element *next;
316 : /* In list form, the previous element in the linked list;
317 : in tree form, the right child node in the tree. */
318 : struct bitmap_element *prev;
319 : /* regno/BITMAP_ELEMENT_ALL_BITS. */
320 : unsigned int indx;
321 : /* Bits that are set, counting from INDX, inclusive */
322 : BITMAP_WORD bits[BITMAP_ELEMENT_WORDS];
323 : };
324 :
325 : /* Head of bitmap linked list. The 'current' member points to something
326 : already pointed to by the chain started by first, so GTY((skip)) it. */
327 :
328 : class GTY(()) bitmap_head {
329 : public:
330 : static bitmap_obstack crashme;
331 : /* Poison obstack to not make it not a valid initialized GC bitmap. */
332 : CONSTEXPR bitmap_head()
333 : : indx (0), tree_form (false), padding (0), alloc_descriptor (0), first (NULL),
334 : current (NULL), obstack (&crashme)
335 : {}
336 : /* Index of last element looked at. */
337 : unsigned int indx;
338 : /* False if the bitmap is in list form; true if the bitmap is in tree form.
339 : Bitmap iterators only work on bitmaps in list form. */
340 : unsigned tree_form: 1;
341 : /* Next integer is shifted, so padding is needed. */
342 : unsigned padding: 2;
343 : /* Bitmap UID used for memory allocation statistics. */
344 : unsigned alloc_descriptor: 29;
345 : /* In list form, the first element in the linked list;
346 : in tree form, the root of the tree. */
347 : bitmap_element *first;
348 : /* Last element looked at. */
349 : bitmap_element * GTY((skip(""))) current;
350 : /* Obstack to allocate elements from. If NULL, then use GGC allocation. */
351 : bitmap_obstack * GTY((skip(""))) obstack;
352 :
353 : /* Dump bitmap. */
354 : void dump ();
355 :
356 : /* Get bitmap descriptor UID casted to an unsigned integer pointer.
357 : Shift the descriptor because pointer_hash<Type>::hash is
358 : doing >> 3 shift operation. */
359 : unsigned *get_descriptor ()
360 : {
361 : return (unsigned *)(ptrdiff_t)(alloc_descriptor << 3);
362 : }
363 : };
364 :
365 : /* Global data */
366 : extern bitmap_element bitmap_zero_bits; /* Zero bitmap element */
367 : extern bitmap_obstack bitmap_default_obstack; /* Default bitmap obstack */
368 :
369 : /* Change the view of the bitmap to list, or tree. */
370 : void bitmap_list_view (bitmap);
371 : void bitmap_tree_view (bitmap);
372 :
373 : /* Clear a bitmap by freeing up the linked list. */
374 : extern void bitmap_clear (bitmap);
375 :
376 : /* Copy a bitmap to another bitmap. */
377 : extern void bitmap_copy (bitmap, const_bitmap);
378 :
379 : /* Move a bitmap to another bitmap. */
380 : extern void bitmap_move (bitmap, bitmap);
381 :
382 : /* True if two bitmaps are identical. */
383 : extern bool bitmap_equal_p (const_bitmap, const_bitmap);
384 :
385 : /* True if the bitmaps intersect (their AND is non-empty). */
386 : extern bool bitmap_intersect_p (const_bitmap, const_bitmap);
387 :
388 : /* True if the complement of the second intersects the first (their
389 : AND_COMPL is non-empty). */
390 : extern bool bitmap_intersect_compl_p (const_bitmap, const_bitmap);
391 :
392 : /* True if MAP is an empty bitmap. */
393 930 : inline bool bitmap_empty_p (const_bitmap map)
394 : {
395 930 : return !map->first;
396 : }
397 :
398 : /* True if the bitmap has only a single bit set. */
399 : extern bool bitmap_single_bit_set_p (const_bitmap);
400 :
401 : /* Count the number of bits set in the bitmap. */
402 : extern unsigned long bitmap_count_bits (const_bitmap);
403 :
404 : /* Count the number of unique bits set across the two bitmaps. */
405 : extern unsigned long bitmap_count_unique_bits (const_bitmap, const_bitmap);
406 :
407 : /* Boolean operations on bitmaps. The _into variants are two operand
408 : versions that modify the first source operand. The other variants
409 : are three operand versions that to not destroy the source bitmaps.
410 : The operations supported are &, & ~, |, ^. */
411 : extern void bitmap_and (bitmap, const_bitmap, const_bitmap);
412 : extern bool bitmap_and_into (bitmap, const_bitmap);
413 : extern bool bitmap_and_compl (bitmap, const_bitmap, const_bitmap);
414 : extern bool bitmap_and_compl_into (bitmap, const_bitmap);
415 : #define bitmap_compl_and(DST, A, B) bitmap_and_compl (DST, B, A)
416 : extern void bitmap_compl_and_into (bitmap, const_bitmap);
417 : extern void bitmap_clear_range (bitmap, unsigned int, unsigned int);
418 : extern void bitmap_set_range (bitmap, unsigned int, unsigned int);
419 : extern bool bitmap_ior (bitmap, const_bitmap, const_bitmap);
420 : extern bool bitmap_ior_into (bitmap, const_bitmap);
421 : extern bool bitmap_ior_into_and_free (bitmap, bitmap *);
422 : extern void bitmap_xor (bitmap, const_bitmap, const_bitmap);
423 : extern void bitmap_xor_into (bitmap, const_bitmap);
424 :
425 : /* DST = A | (B & C). Return true if DST changes. */
426 : extern bool bitmap_ior_and_into (bitmap DST, const_bitmap B, const_bitmap C);
427 : /* DST = A | (B & ~C). Return true if DST changes. */
428 : extern bool bitmap_ior_and_compl (bitmap DST, const_bitmap A,
429 : const_bitmap B, const_bitmap C);
430 : /* A |= (B & ~C). Return true if A changes. */
431 : extern bool bitmap_ior_and_compl_into (bitmap A,
432 : const_bitmap B, const_bitmap C);
433 :
434 : /* Clear a single bit in a bitmap. Return true if the bit changed. */
435 : extern bool bitmap_clear_bit (bitmap, int);
436 :
437 : /* Set a single bit in a bitmap. Return true if the bit changed. */
438 : extern bool bitmap_set_bit (bitmap, int);
439 :
440 : /* Return true if a bit is set in a bitmap. */
441 : extern bool bitmap_bit_p (const_bitmap, int);
442 :
443 : /* Set and get multiple bit values in a sparse bitmap. This allows a bitmap to
444 : function as a sparse array of bit patterns where the patterns are
445 : multiples of power of 2. This is more efficient than performing this as
446 : multiple individual operations. */
447 : void bitmap_set_aligned_chunk (bitmap, unsigned int, unsigned int, BITMAP_WORD);
448 : BITMAP_WORD bitmap_get_aligned_chunk (const_bitmap, unsigned int, unsigned int);
449 :
450 : /* Debug functions to print a bitmap. */
451 : extern void debug_bitmap (const_bitmap);
452 : extern void debug_bitmap_file (FILE *, const_bitmap);
453 :
454 : /* Print a bitmap. */
455 : extern void bitmap_print (FILE *, const_bitmap, const char *, const char *);
456 :
457 : /* Initialize and release a bitmap obstack. */
458 : extern void bitmap_obstack_initialize (bitmap_obstack *);
459 : extern void bitmap_obstack_release (bitmap_obstack *);
460 : extern void bitmap_register (bitmap MEM_STAT_DECL);
461 : extern void dump_bitmap_statistics (void);
462 :
463 : /* Initialize a bitmap header. OBSTACK indicates the bitmap obstack
464 : to allocate from, NULL for GC'd bitmap. */
465 :
466 : inline void
467 64600 : bitmap_initialize (bitmap head, bitmap_obstack *obstack CXX_MEM_STAT_INFO)
468 : {
469 64600 : head->first = head->current = NULL;
470 64600 : head->indx = head->tree_form = 0;
471 64600 : head->padding = 0;
472 64600 : head->alloc_descriptor = 0;
473 64600 : head->obstack = obstack;
474 64600 : if (GATHER_STATISTICS)
475 : bitmap_register (head PASS_MEM_STAT);
476 : }
477 :
478 : /* Release a bitmap (but not its head). This is suitable for pairing with
479 : bitmap_initialize. */
480 :
481 : inline void
482 : bitmap_release (bitmap head)
483 : {
484 : bitmap_clear (head);
485 : /* Poison the obstack pointer so the obstack can be safely released.
486 : Do not zero it as the bitmap then becomes initialized GC. */
487 : head->obstack = &bitmap_head::crashme;
488 : }
489 :
490 : /* Allocate and free bitmaps from obstack, malloc and gc'd memory. */
491 : extern bitmap bitmap_alloc (bitmap_obstack *obstack CXX_MEM_STAT_INFO);
492 : #define BITMAP_ALLOC bitmap_alloc
493 : extern bitmap bitmap_gc_alloc (ALONE_CXX_MEM_STAT_INFO);
494 : #define BITMAP_GGC_ALLOC bitmap_gc_alloc
495 : extern void bitmap_obstack_free (bitmap);
496 :
497 : /* A few compatibility/functions macros for compatibility with sbitmaps */
498 : inline void dump_bitmap (FILE *file, const_bitmap map)
499 : {
500 : bitmap_print (file, map, "", "\n");
501 : }
502 : extern void debug (const bitmap_head &ref);
503 : extern void debug (const bitmap_head *ptr);
504 :
505 : extern unsigned bitmap_first_set_bit (const_bitmap);
506 : extern unsigned bitmap_clear_first_set_bit (bitmap);
507 : extern unsigned bitmap_last_set_bit (const_bitmap);
508 :
509 : /* Compute bitmap hash (for purposes of hashing etc.) */
510 : extern hashval_t bitmap_hash (const_bitmap);
511 :
512 : /* Do any cleanup needed on a bitmap when it is no longer used. */
513 : #define BITMAP_FREE(BITMAP) \
514 : ((void) (bitmap_obstack_free ((bitmap) BITMAP), (BITMAP) = (bitmap) NULL))
515 :
516 : /* Iterator for bitmaps. */
517 :
518 : struct bitmap_iterator
519 : {
520 : /* Pointer to the current bitmap element. */
521 : bitmap_element *elt1;
522 :
523 : /* Pointer to 2nd bitmap element when two are involved. */
524 : bitmap_element *elt2;
525 :
526 : /* Word within the current element. */
527 : unsigned word_no;
528 :
529 : /* Contents of the actually processed word. When finding next bit
530 : it is shifted right, so that the actual bit is always the least
531 : significant bit of ACTUAL. */
532 : BITMAP_WORD bits;
533 : };
534 :
535 : /* Initialize a single bitmap iterator. START_BIT is the first bit to
536 : iterate from. */
537 :
538 : inline void
539 651 : bmp_iter_set_init (bitmap_iterator *bi, const_bitmap map,
540 : unsigned start_bit, unsigned *bit_no)
541 : {
542 651 : bi->elt1 = map->first;
543 651 : bi->elt2 = NULL;
544 :
545 651 : gcc_checking_assert (!map->tree_form);
546 :
547 : /* Advance elt1 until it is not before the block containing start_bit. */
548 651 : while (1)
549 : {
550 651 : if (!bi->elt1)
551 : {
552 0 : bi->elt1 = &bitmap_zero_bits;
553 0 : break;
554 : }
555 :
556 651 : if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
557 : break;
558 0 : bi->elt1 = bi->elt1->next;
559 : }
560 :
561 : /* We might have gone past the start bit, so reinitialize it. */
562 651 : if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
563 0 : start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
564 :
565 : /* Initialize for what is now start_bit. */
566 651 : bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
567 651 : bi->bits = bi->elt1->bits[bi->word_no];
568 651 : bi->bits >>= start_bit % BITMAP_WORD_BITS;
569 :
570 : /* If this word is zero, we must make sure we're not pointing at the
571 : first bit, otherwise our incrementing to the next word boundary
572 : will fail. It won't matter if this increment moves us into the
573 : next word. */
574 651 : start_bit += !bi->bits;
575 :
576 651 : *bit_no = start_bit;
577 651 : }
578 :
579 : /* Initialize an iterator to iterate over the intersection of two
580 : bitmaps. START_BIT is the bit to commence from. */
581 :
582 : inline void
583 : bmp_iter_and_init (bitmap_iterator *bi, const_bitmap map1, const_bitmap map2,
584 : unsigned start_bit, unsigned *bit_no)
585 : {
586 : bi->elt1 = map1->first;
587 : bi->elt2 = map2->first;
588 :
589 : gcc_checking_assert (!map1->tree_form && !map2->tree_form);
590 :
591 : /* Advance elt1 until it is not before the block containing
592 : start_bit. */
593 : while (1)
594 : {
595 : if (!bi->elt1)
596 : {
597 : bi->elt2 = NULL;
598 : break;
599 : }
600 :
601 : if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
602 : break;
603 : bi->elt1 = bi->elt1->next;
604 : }
605 :
606 : /* Advance elt2 until it is not before elt1. */
607 : while (1)
608 : {
609 : if (!bi->elt2)
610 : {
611 : bi->elt1 = bi->elt2 = &bitmap_zero_bits;
612 : break;
613 : }
614 :
615 : if (bi->elt2->indx >= bi->elt1->indx)
616 : break;
617 : bi->elt2 = bi->elt2->next;
618 : }
619 :
620 : /* If we're at the same index, then we have some intersecting bits. */
621 : if (bi->elt1->indx == bi->elt2->indx)
622 : {
623 : /* We might have advanced beyond the start_bit, so reinitialize
624 : for that. */
625 : if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
626 : start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
627 :
628 : bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
629 : bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
630 : bi->bits >>= start_bit % BITMAP_WORD_BITS;
631 : }
632 : else
633 : {
634 : /* Otherwise we must immediately advance elt1, so initialize for
635 : that. */
636 : bi->word_no = BITMAP_ELEMENT_WORDS - 1;
637 : bi->bits = 0;
638 : }
639 :
640 : /* If this word is zero, we must make sure we're not pointing at the
641 : first bit, otherwise our incrementing to the next word boundary
642 : will fail. It won't matter if this increment moves us into the
643 : next word. */
644 : start_bit += !bi->bits;
645 :
646 : *bit_no = start_bit;
647 : }
648 :
649 : /* Initialize an iterator to iterate over the bits in MAP1 & ~MAP2. */
650 :
651 : inline void
652 : bmp_iter_and_compl_init (bitmap_iterator *bi,
653 : const_bitmap map1, const_bitmap map2,
654 : unsigned start_bit, unsigned *bit_no)
655 : {
656 : bi->elt1 = map1->first;
657 : bi->elt2 = map2->first;
658 :
659 : gcc_checking_assert (!map1->tree_form && !map2->tree_form);
660 :
661 : /* Advance elt1 until it is not before the block containing start_bit. */
662 : while (1)
663 : {
664 : if (!bi->elt1)
665 : {
666 : bi->elt1 = &bitmap_zero_bits;
667 : break;
668 : }
669 :
670 : if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
671 : break;
672 : bi->elt1 = bi->elt1->next;
673 : }
674 :
675 : /* Advance elt2 until it is not before elt1. */
676 : while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
677 : bi->elt2 = bi->elt2->next;
678 :
679 : /* We might have advanced beyond the start_bit, so reinitialize for
680 : that. */
681 : if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
682 : start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
683 :
684 : bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
685 : bi->bits = bi->elt1->bits[bi->word_no];
686 : if (bi->elt2 && bi->elt1->indx == bi->elt2->indx)
687 : bi->bits &= ~bi->elt2->bits[bi->word_no];
688 : bi->bits >>= start_bit % BITMAP_WORD_BITS;
689 :
690 : /* If this word is zero, we must make sure we're not pointing at the
691 : first bit, otherwise our incrementing to the next word boundary
692 : will fail. It won't matter if this increment moves us into the
693 : next word. */
694 : start_bit += !bi->bits;
695 :
696 : *bit_no = start_bit;
697 : }
698 :
699 : /* Advance to the next bit in BI. We don't advance to the next
700 : nonzero bit yet. */
701 :
702 : inline void
703 680 : bmp_iter_next (bitmap_iterator *bi, unsigned *bit_no)
704 : {
705 680 : bi->bits >>= 1;
706 680 : *bit_no += 1;
707 680 : }
708 :
709 : /* Advance to first set bit in BI. */
710 :
711 : inline void
712 680 : bmp_iter_next_bit (bitmap_iterator * bi, unsigned *bit_no)
713 : {
714 : #if (GCC_VERSION >= 3004)
715 680 : {
716 680 : unsigned int n = __builtin_ctzl (bi->bits);
717 680 : gcc_assert (sizeof (unsigned long) == sizeof (BITMAP_WORD));
718 680 : bi->bits >>= n;
719 680 : *bit_no += n;
720 : }
721 : #else
722 : while (!(bi->bits & 1))
723 : {
724 : bi->bits >>= 1;
725 : *bit_no += 1;
726 : }
727 : #endif
728 : }
729 :
730 : /* Advance to the next nonzero bit of a single bitmap, we will have
731 : already advanced past the just iterated bit. Return true if there
732 : is a bit to iterate. */
733 :
734 : inline bool
735 1331 : bmp_iter_set (bitmap_iterator *bi, unsigned *bit_no)
736 : {
737 : /* If our current word is nonzero, it contains the bit we want. */
738 1331 : if (bi->bits)
739 : {
740 680 : next_bit:
741 680 : bmp_iter_next_bit (bi, bit_no);
742 680 : return true;
743 : }
744 :
745 : /* Round up to the word boundary. We might have just iterated past
746 : the end of the last word, hence the -1. It is not possible for
747 : bit_no to point at the beginning of the now last word. */
748 651 : *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
749 651 : / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
750 651 : bi->word_no++;
751 :
752 0 : while (1)
753 : {
754 : /* Find the next nonzero word in this elt. */
755 1302 : while (bi->word_no != BITMAP_ELEMENT_WORDS)
756 : {
757 651 : bi->bits = bi->elt1->bits[bi->word_no];
758 651 : if (bi->bits)
759 0 : goto next_bit;
760 651 : *bit_no += BITMAP_WORD_BITS;
761 651 : bi->word_no++;
762 : }
763 :
764 : /* Make sure we didn't remove the element while iterating. */
765 651 : gcc_checking_assert (bi->elt1->indx != -1U);
766 :
767 : /* Advance to the next element. */
768 651 : bi->elt1 = bi->elt1->next;
769 651 : if (!bi->elt1)
770 : return false;
771 0 : *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
772 0 : bi->word_no = 0;
773 : }
774 : }
775 :
776 : /* Advance to the next nonzero bit of an intersecting pair of
777 : bitmaps. We will have already advanced past the just iterated bit.
778 : Return true if there is a bit to iterate. */
779 :
780 : inline bool
781 : bmp_iter_and (bitmap_iterator *bi, unsigned *bit_no)
782 : {
783 : /* If our current word is nonzero, it contains the bit we want. */
784 : if (bi->bits)
785 : {
786 : next_bit:
787 : bmp_iter_next_bit (bi, bit_no);
788 : return true;
789 : }
790 :
791 : /* Round up to the word boundary. We might have just iterated past
792 : the end of the last word, hence the -1. It is not possible for
793 : bit_no to point at the beginning of the now last word. */
794 : *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
795 : / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
796 : bi->word_no++;
797 :
798 : while (1)
799 : {
800 : /* Find the next nonzero word in this elt. */
801 : while (bi->word_no != BITMAP_ELEMENT_WORDS)
802 : {
803 : bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
804 : if (bi->bits)
805 : goto next_bit;
806 : *bit_no += BITMAP_WORD_BITS;
807 : bi->word_no++;
808 : }
809 :
810 : /* Advance to the next identical element. */
811 : do
812 : {
813 : /* Make sure we didn't remove the element while iterating. */
814 : gcc_checking_assert (bi->elt1->indx != -1U);
815 :
816 : /* Advance elt1 while it is less than elt2. We always want
817 : to advance one elt. */
818 : do
819 : {
820 : bi->elt1 = bi->elt1->next;
821 : if (!bi->elt1)
822 : return false;
823 : }
824 : while (bi->elt1->indx < bi->elt2->indx);
825 :
826 : /* Make sure we didn't remove the element while iterating. */
827 : gcc_checking_assert (bi->elt2->indx != -1U);
828 :
829 : /* Advance elt2 to be no less than elt1. This might not
830 : advance. */
831 : while (bi->elt2->indx < bi->elt1->indx)
832 : {
833 : bi->elt2 = bi->elt2->next;
834 : if (!bi->elt2)
835 : return false;
836 : }
837 : }
838 : while (bi->elt1->indx != bi->elt2->indx);
839 :
840 : *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
841 : bi->word_no = 0;
842 : }
843 : }
844 :
845 : /* Advance to the next nonzero bit in the intersection of
846 : complemented bitmaps. We will have already advanced past the just
847 : iterated bit. */
848 :
849 : inline bool
850 : bmp_iter_and_compl (bitmap_iterator *bi, unsigned *bit_no)
851 : {
852 : /* If our current word is nonzero, it contains the bit we want. */
853 : if (bi->bits)
854 : {
855 : next_bit:
856 : bmp_iter_next_bit (bi, bit_no);
857 : return true;
858 : }
859 :
860 : /* Round up to the word boundary. We might have just iterated past
861 : the end of the last word, hence the -1. It is not possible for
862 : bit_no to point at the beginning of the now last word. */
863 : *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
864 : / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
865 : bi->word_no++;
866 :
867 : while (1)
868 : {
869 : /* Find the next nonzero word in this elt. */
870 : while (bi->word_no != BITMAP_ELEMENT_WORDS)
871 : {
872 : bi->bits = bi->elt1->bits[bi->word_no];
873 : if (bi->elt2 && bi->elt2->indx == bi->elt1->indx)
874 : bi->bits &= ~bi->elt2->bits[bi->word_no];
875 : if (bi->bits)
876 : goto next_bit;
877 : *bit_no += BITMAP_WORD_BITS;
878 : bi->word_no++;
879 : }
880 :
881 : /* Make sure we didn't remove the element while iterating. */
882 : gcc_checking_assert (bi->elt1->indx != -1U);
883 :
884 : /* Advance to the next element of elt1. */
885 : bi->elt1 = bi->elt1->next;
886 : if (!bi->elt1)
887 : return false;
888 :
889 : /* Make sure we didn't remove the element while iterating. */
890 : gcc_checking_assert (! bi->elt2 || bi->elt2->indx != -1U);
891 :
892 : /* Advance elt2 until it is no less than elt1. */
893 : while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
894 : bi->elt2 = bi->elt2->next;
895 :
896 : *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
897 : bi->word_no = 0;
898 : }
899 : }
900 :
901 : /* If you are modifying a bitmap you are currently iterating over you
902 : have to ensure to
903 : - never remove the current bit;
904 : - if you set or clear a bit before the current bit this operation
905 : will not affect the set of bits you are visiting during the iteration;
906 : - if you set or clear a bit after the current bit it is unspecified
907 : whether that affects the set of bits you are visiting during the
908 : iteration.
909 : If you want to remove the current bit you can delay this to the next
910 : iteration (and after the iteration in case the last iteration is
911 : affected). */
912 :
913 : /* Loop over all bits set in BITMAP, starting with MIN and setting
914 : BITNUM to the bit number. ITER is a bitmap iterator. BITNUM
915 : should be treated as a read-only variable as it contains loop
916 : state. */
917 :
918 : #ifndef EXECUTE_IF_SET_IN_BITMAP
919 : /* See sbitmap.h for the other definition of EXECUTE_IF_SET_IN_BITMAP. */
920 : #define EXECUTE_IF_SET_IN_BITMAP(BITMAP, MIN, BITNUM, ITER) \
921 : for (bmp_iter_set_init (&(ITER), (BITMAP), (MIN), &(BITNUM)); \
922 : bmp_iter_set (&(ITER), &(BITNUM)); \
923 : bmp_iter_next (&(ITER), &(BITNUM)))
924 : #endif
925 :
926 : /* Loop over all the bits set in BITMAP1 & BITMAP2, starting with MIN
927 : and setting BITNUM to the bit number. ITER is a bitmap iterator.
928 : BITNUM should be treated as a read-only variable as it contains
929 : loop state. */
930 :
931 : #define EXECUTE_IF_AND_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER) \
932 : for (bmp_iter_and_init (&(ITER), (BITMAP1), (BITMAP2), (MIN), \
933 : &(BITNUM)); \
934 : bmp_iter_and (&(ITER), &(BITNUM)); \
935 : bmp_iter_next (&(ITER), &(BITNUM)))
936 :
937 : /* Loop over all the bits set in BITMAP1 & ~BITMAP2, starting with MIN
938 : and setting BITNUM to the bit number. ITER is a bitmap iterator.
939 : BITNUM should be treated as a read-only variable as it contains
940 : loop state. */
941 :
942 : #define EXECUTE_IF_AND_COMPL_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER) \
943 : for (bmp_iter_and_compl_init (&(ITER), (BITMAP1), (BITMAP2), (MIN), \
944 : &(BITNUM)); \
945 : bmp_iter_and_compl (&(ITER), &(BITNUM)); \
946 : bmp_iter_next (&(ITER), &(BITNUM)))
947 :
948 : /* A class that ties the lifetime of a bitmap to its scope. */
949 : class auto_bitmap
950 : {
951 : public:
952 : auto_bitmap (ALONE_CXX_MEM_STAT_INFO)
953 : { bitmap_initialize (&m_bits, &bitmap_default_obstack PASS_MEM_STAT); }
954 : explicit auto_bitmap (bitmap_obstack *o CXX_MEM_STAT_INFO)
955 : { bitmap_initialize (&m_bits, o PASS_MEM_STAT); }
956 : ~auto_bitmap () { bitmap_clear (&m_bits); }
957 : // Allow calling bitmap functions on our bitmap.
958 : operator bitmap () { return &m_bits; }
959 :
960 : private:
961 : // Prevent making a copy that references our bitmap.
962 : auto_bitmap (const auto_bitmap &);
963 : auto_bitmap &operator = (const auto_bitmap &);
964 : auto_bitmap (auto_bitmap &&);
965 : auto_bitmap &operator = (auto_bitmap &&);
966 :
967 : bitmap_head m_bits;
968 : };
969 :
970 : extern void debug (const auto_bitmap &ref);
971 : extern void debug (const auto_bitmap *ptr);
972 :
973 : /* Base class for bitmap_view; see there for details. */
974 : template<typename T, typename Traits = array_traits<T> >
975 : class base_bitmap_view
976 : {
977 : public:
978 : typedef typename Traits::element_type array_element_type;
979 :
980 : base_bitmap_view (const T &, bitmap_element *);
981 : operator const_bitmap () const { return &m_head; }
982 :
983 : private:
984 : base_bitmap_view (const base_bitmap_view &);
985 :
986 : bitmap_head m_head;
987 : };
988 :
989 : /* Provides a read-only bitmap view of a single integer bitmask or a
990 : constant-sized array of integer bitmasks, or of a wrapper around such
991 : bitmasks. */
992 : template<typename T, typename Traits>
993 : class bitmap_view<T, Traits, true> : public base_bitmap_view<T, Traits>
994 : {
995 : public:
996 : bitmap_view (const T &array)
997 : : base_bitmap_view<T, Traits> (array, m_bitmap_elements) {}
998 :
999 : private:
1000 : /* How many bitmap_elements we need to hold a full T. */
1001 : static const size_t num_bitmap_elements
1002 : = CEIL (CHAR_BIT
1003 : * sizeof (typename Traits::element_type)
1004 : * Traits::constant_size,
1005 : BITMAP_ELEMENT_ALL_BITS);
1006 : bitmap_element m_bitmap_elements[num_bitmap_elements];
1007 : };
1008 :
1009 : /* Initialize the view for array ARRAY, using the array of bitmap
1010 : elements in BITMAP_ELEMENTS (which is known to contain enough
1011 : entries). */
1012 : template<typename T, typename Traits>
1013 : base_bitmap_view<T, Traits>::base_bitmap_view (const T &array,
1014 : bitmap_element *bitmap_elements)
1015 : {
1016 : m_head.obstack = NULL;
1017 :
1018 : /* The code currently assumes that each element of ARRAY corresponds
1019 : to exactly one bitmap_element. */
1020 : const size_t array_element_bits = CHAR_BIT * sizeof (array_element_type);
1021 : STATIC_ASSERT (BITMAP_ELEMENT_ALL_BITS % array_element_bits == 0);
1022 : size_t array_step = BITMAP_ELEMENT_ALL_BITS / array_element_bits;
1023 : size_t array_size = Traits::size (array);
1024 :
1025 : /* Process each potential bitmap_element in turn. The loop is written
1026 : this way rather than per array element because usually there are
1027 : only a small number of array elements per bitmap element (typically
1028 : two or four). The inner loops should therefore unroll completely. */
1029 : const array_element_type *array_elements = Traits::base (array);
1030 : unsigned int indx = 0;
1031 : for (size_t array_base = 0;
1032 : array_base < array_size;
1033 : array_base += array_step, indx += 1)
1034 : {
1035 : /* How many array elements are in this particular bitmap_element. */
1036 : unsigned int array_count
1037 : = (STATIC_CONSTANT_P (array_size % array_step == 0)
1038 : ? array_step : MIN (array_step, array_size - array_base));
1039 :
1040 : /* See whether we need this bitmap element. */
1041 : array_element_type ior = array_elements[array_base];
1042 : for (size_t i = 1; i < array_count; ++i)
1043 : ior |= array_elements[array_base + i];
1044 : if (ior == 0)
1045 : continue;
1046 :
1047 : /* Grab the next bitmap element and chain it. */
1048 : bitmap_element *bitmap_element = bitmap_elements++;
1049 : if (m_head.current)
1050 : m_head.current->next = bitmap_element;
1051 : else
1052 : m_head.first = bitmap_element;
1053 : bitmap_element->prev = m_head.current;
1054 : bitmap_element->next = NULL;
1055 : bitmap_element->indx = indx;
1056 : m_head.current = bitmap_element;
1057 : m_head.indx = indx;
1058 :
1059 : /* Fill in the bits of the bitmap element. */
1060 : if (array_element_bits < BITMAP_WORD_BITS)
1061 : {
1062 : /* Multiple array elements fit in one element of
1063 : bitmap_element->bits. */
1064 : size_t array_i = array_base;
1065 : for (unsigned int word_i = 0; word_i < BITMAP_ELEMENT_WORDS;
1066 : ++word_i)
1067 : {
1068 : BITMAP_WORD word = 0;
1069 : for (unsigned int shift = 0;
1070 : shift < BITMAP_WORD_BITS && array_i < array_size;
1071 : shift += array_element_bits)
1072 : word |= array_elements[array_i++] << shift;
1073 : bitmap_element->bits[word_i] = word;
1074 : }
1075 : }
1076 : else
1077 : {
1078 : /* Array elements are the same size as elements of
1079 : bitmap_element->bits, or are an exact multiple of that size. */
1080 : unsigned int word_i = 0;
1081 : for (unsigned int i = 0; i < array_count; ++i)
1082 : for (unsigned int shift = 0; shift < array_element_bits;
1083 : shift += BITMAP_WORD_BITS)
1084 : bitmap_element->bits[word_i++]
1085 : = array_elements[array_base + i] >> shift;
1086 : while (word_i < BITMAP_ELEMENT_WORDS)
1087 : bitmap_element->bits[word_i++] = 0;
1088 : }
1089 : }
1090 : }
1091 :
1092 : #endif /* GCC_BITMAP_H */
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