1/* Functions to support general ended bitmaps.
2   Copyright (C) 1997-2015 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along 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.
24
25   This sparse set representation is suitable for sparse sets with an
26   unknown (a priori) universe.  The set is represented as a double-linked
27   list of container nodes (struct bitmap_element).  Each node consists
28   of an index for the first member that could be held in the container,
29   a small array of integers that represent the members in the container,
30   and pointers to the next and previous element in the linked list.  The
31   elements in the list are sorted in ascending order, i.e. the head of
32   the list holds the element with the smallest member of the set.
33
34   For a given member I in the set:
35     - the element for I will have index is I / (bits per element)
36     - the position for I within element is I % (bits per element)
37
38   This representation is very space-efficient for large sparse sets, and
39   the size of the set can be changed dynamically without much overhead.
40   An important parameter is the number of bits per element.  In this
41   implementation, there are 128 bits per element.  This results in a
42   high storage overhead *per element*, but a small overall overhead if
43   the set is very sparse.
44
45   The downside is that many operations are relatively slow because the
46   linked list has to be traversed to test membership (i.e. member_p/
47   add_member/remove_member).  To improve the performance of this set
48   representation, the last accessed element and its index are cached.
49   For membership tests on members close to recently accessed members,
50   the cached last element improves membership test to a constant-time
51   operation.
52
53   The following operations can always be performed in O(1) time:
54
55     * clear			: bitmap_clear
56     * choose_one		: (not implemented, but could be
57				   implemented in constant time)
58
59   The following operations can be performed in O(E) time worst-case (with
60   E the number of elements in the linked list), but in O(1) time with a
61   suitable access patterns:
62
63     * member_p			: bitmap_bit_p
64     * add_member		: bitmap_set_bit
65     * remove_member		: bitmap_clear_bit
66
67   The following operations can be performed in O(E) time:
68
69     * cardinality		: bitmap_count_bits
70     * set_size			: bitmap_last_set_bit (but this could
71				  in constant time with a pointer to
72				  the last element in the chain)
73
74   Additionally, the linked-list sparse set representation supports
75   enumeration of the members in O(E) time:
76
77     * forall			: EXECUTE_IF_SET_IN_BITMAP
78     * set_copy			: bitmap_copy
79     * set_intersection		: bitmap_intersect_p /
80				  bitmap_and / bitmap_and_into /
81				  EXECUTE_IF_AND_IN_BITMAP
82     * set_union		: bitmap_ior / bitmap_ior_into
83     * set_difference		: bitmap_intersect_compl_p /
84				  bitmap_and_comp / bitmap_and_comp_into /
85				  EXECUTE_IF_AND_COMPL_IN_BITMAP
86     * set_disjuction		: bitmap_xor_comp / bitmap_xor_comp_into
87     * set_compare		: bitmap_equal_p
88
89   Some operations on 3 sets that occur frequently in in data flow problems
90   are also implemented:
91
92     * A | (B & C)		: bitmap_ior_and_into
93     * A | (B & ~C)		: bitmap_ior_and_compl /
94				  bitmap_ior_and_compl_into
95
96   The storage requirements for linked-list sparse sets are O(E), with E->N
97   in the worst case (a sparse set with large distances between the values
98   of the set members).
99
100   The linked-list set representation works well for problems involving very
101   sparse sets.  The canonical example in GCC is, of course, the "set of
102   sets" for some CFG-based data flow problems (liveness analysis, dominance
103   frontiers, etc.).
104
105   This representation also works well for data flow problems where the size
106   of the set may grow dynamically, but care must be taken that the member_p,
107   add_member, and remove_member operations occur with a suitable access
108   pattern.
109
110   For random-access sets with a known, relatively small universe size, the
111   SparseSet or simple bitmap representations may be more efficient than a
112   linked-list set.  For random-access sets of unknown universe, a hash table
113   or a balanced binary tree representation is likely to be a more suitable
114   choice.
115
116   Traversing linked lists is usually cache-unfriendly, even with the last
117   accessed element cached.
118
119   Cache performance can be improved by keeping the elements in the set
120   grouped together in memory, using a dedicated obstack for a set (or group
121   of related sets).  Elements allocated on obstacks are released to a
122   free-list and taken off the free list.  If multiple sets are allocated on
123   the same obstack, elements freed from one set may be re-used for one of
124   the other sets.  This usually helps avoid cache misses.
125
126   A single free-list is used for all sets allocated in GGC space.  This is
127   bad for persistent sets, so persistent sets should be allocated on an
128   obstack whenever possible.  */
129
130#include "hashtab.h"
131#include "statistics.h"
132#include "obstack.h"
133
134/* Fundamental storage type for bitmap.  */
135
136typedef unsigned long BITMAP_WORD;
137/* BITMAP_WORD_BITS needs to be unsigned, but cannot contain casts as
138   it is used in preprocessor directives -- hence the 1u.  */
139#define BITMAP_WORD_BITS (CHAR_BIT * SIZEOF_LONG * 1u)
140
141/* Number of words to use for each element in the linked list.  */
142
143#ifndef BITMAP_ELEMENT_WORDS
144#define BITMAP_ELEMENT_WORDS ((128 + BITMAP_WORD_BITS - 1) / BITMAP_WORD_BITS)
145#endif
146
147/* Number of bits in each actual element of a bitmap.  */
148
149#define BITMAP_ELEMENT_ALL_BITS (BITMAP_ELEMENT_WORDS * BITMAP_WORD_BITS)
150
151/* Obstack for allocating bitmaps and elements from.  */
152struct GTY (()) bitmap_obstack {
153  struct bitmap_element *elements;
154  struct bitmap_head *heads;
155  struct obstack GTY ((skip)) obstack;
156};
157
158/* Bitmap set element.  We use a linked list to hold only the bits that
159   are set.  This allows for use to grow the bitset dynamically without
160   having to realloc and copy a giant bit array.
161
162   The free list is implemented as a list of lists.  There is one
163   outer list connected together by prev fields.  Each element of that
164   outer is an inner list (that may consist only of the outer list
165   element) that are connected by the next fields.  The prev pointer
166   is undefined for interior elements.  This allows
167   bitmap_elt_clear_from to be implemented in unit time rather than
168   linear in the number of elements to be freed.  */
169
170struct GTY((chain_next ("%h.next"), chain_prev ("%h.prev"))) bitmap_element {
171  struct bitmap_element *next;	/* Next element.  */
172  struct bitmap_element *prev;	/* Previous element.  */
173  unsigned int indx;			/* regno/BITMAP_ELEMENT_ALL_BITS.  */
174  BITMAP_WORD bits[BITMAP_ELEMENT_WORDS]; /* Bits that are set.  */
175};
176
177/* Head of bitmap linked list.  The 'current' member points to something
178   already pointed to by the chain started by first, so GTY((skip)) it.  */
179
180struct GTY(()) bitmap_head {
181  unsigned int indx;			/* Index of last element looked at.  */
182  unsigned int descriptor_id;		/* Unique identifier for the allocation
183					   site of this bitmap, for detailed
184					   statistics gathering.  */
185  bitmap_element *first;		/* First element in linked list.  */
186  bitmap_element * GTY((skip(""))) current; /* Last element looked at.  */
187  bitmap_obstack *obstack;		/* Obstack to allocate elements from.
188					   If NULL, then use GGC allocation.  */
189};
190
191/* Global data */
192extern bitmap_element bitmap_zero_bits;	/* Zero bitmap element */
193extern bitmap_obstack bitmap_default_obstack;   /* Default bitmap obstack */
194
195/* Clear a bitmap by freeing up the linked list.  */
196extern void bitmap_clear (bitmap);
197
198/* Copy a bitmap to another bitmap.  */
199extern void bitmap_copy (bitmap, const_bitmap);
200
201/* True if two bitmaps are identical.  */
202extern bool bitmap_equal_p (const_bitmap, const_bitmap);
203
204/* True if the bitmaps intersect (their AND is non-empty).  */
205extern bool bitmap_intersect_p (const_bitmap, const_bitmap);
206
207/* True if the complement of the second intersects the first (their
208   AND_COMPL is non-empty).  */
209extern bool bitmap_intersect_compl_p (const_bitmap, const_bitmap);
210
211/* True if MAP is an empty bitmap.  */
212inline bool bitmap_empty_p (const_bitmap map)
213{
214  return !map->first;
215}
216
217/* True if the bitmap has only a single bit set.  */
218extern bool bitmap_single_bit_set_p (const_bitmap);
219
220/* Count the number of bits set in the bitmap.  */
221extern unsigned long bitmap_count_bits (const_bitmap);
222
223/* Boolean operations on bitmaps.  The _into variants are two operand
224   versions that modify the first source operand.  The other variants
225   are three operand versions that to not destroy the source bitmaps.
226   The operations supported are &, & ~, |, ^.  */
227extern void bitmap_and (bitmap, const_bitmap, const_bitmap);
228extern bool bitmap_and_into (bitmap, const_bitmap);
229extern bool bitmap_and_compl (bitmap, const_bitmap, const_bitmap);
230extern bool bitmap_and_compl_into (bitmap, const_bitmap);
231#define bitmap_compl_and(DST, A, B) bitmap_and_compl (DST, B, A)
232extern void bitmap_compl_and_into (bitmap, const_bitmap);
233extern void bitmap_clear_range (bitmap, unsigned int, unsigned int);
234extern void bitmap_set_range (bitmap, unsigned int, unsigned int);
235extern bool bitmap_ior (bitmap, const_bitmap, const_bitmap);
236extern bool bitmap_ior_into (bitmap, const_bitmap);
237extern void bitmap_xor (bitmap, const_bitmap, const_bitmap);
238extern void bitmap_xor_into (bitmap, const_bitmap);
239
240/* DST = A | (B & C).  Return true if DST changes.  */
241extern bool bitmap_ior_and_into (bitmap DST, const_bitmap B, const_bitmap C);
242/* DST = A | (B & ~C).  Return true if DST changes.  */
243extern bool bitmap_ior_and_compl (bitmap DST, const_bitmap A,
244				  const_bitmap B, const_bitmap C);
245/* A |= (B & ~C).  Return true if A changes.  */
246extern bool bitmap_ior_and_compl_into (bitmap A,
247				       const_bitmap B, const_bitmap C);
248
249/* Clear a single bit in a bitmap.  Return true if the bit changed.  */
250extern bool bitmap_clear_bit (bitmap, int);
251
252/* Set a single bit in a bitmap.  Return true if the bit changed.  */
253extern bool bitmap_set_bit (bitmap, int);
254
255/* Return true if a register is set in a register set.  */
256extern int bitmap_bit_p (bitmap, int);
257
258/* Debug functions to print a bitmap linked list.  */
259extern void debug_bitmap (const_bitmap);
260extern void debug_bitmap_file (FILE *, const_bitmap);
261
262/* Print a bitmap.  */
263extern void bitmap_print (FILE *, const_bitmap, const char *, const char *);
264
265/* Initialize and release a bitmap obstack.  */
266extern void bitmap_obstack_initialize (bitmap_obstack *);
267extern void bitmap_obstack_release (bitmap_obstack *);
268extern void bitmap_register (bitmap MEM_STAT_DECL);
269extern void dump_bitmap_statistics (void);
270
271/* Initialize a bitmap header.  OBSTACK indicates the bitmap obstack
272   to allocate from, NULL for GC'd bitmap.  */
273
274static inline void
275bitmap_initialize_stat (bitmap head, bitmap_obstack *obstack MEM_STAT_DECL)
276{
277  head->first = head->current = NULL;
278  head->obstack = obstack;
279  if (GATHER_STATISTICS)
280    bitmap_register (head PASS_MEM_STAT);
281}
282#define bitmap_initialize(h,o) bitmap_initialize_stat (h,o MEM_STAT_INFO)
283
284/* Allocate and free bitmaps from obstack, malloc and gc'd memory.  */
285extern bitmap bitmap_obstack_alloc_stat (bitmap_obstack *obstack MEM_STAT_DECL);
286#define bitmap_obstack_alloc(t) bitmap_obstack_alloc_stat (t MEM_STAT_INFO)
287extern bitmap bitmap_gc_alloc_stat (ALONE_MEM_STAT_DECL);
288#define bitmap_gc_alloc() bitmap_gc_alloc_stat (ALONE_MEM_STAT_INFO)
289extern void bitmap_obstack_free (bitmap);
290
291/* A few compatibility/functions macros for compatibility with sbitmaps */
292inline void dump_bitmap (FILE *file, const_bitmap map)
293{
294  bitmap_print (file, map, "", "\n");
295}
296extern void debug (const bitmap_head &ref);
297extern void debug (const bitmap_head *ptr);
298
299extern unsigned bitmap_first_set_bit (const_bitmap);
300extern unsigned bitmap_last_set_bit (const_bitmap);
301
302/* Compute bitmap hash (for purposes of hashing etc.)  */
303extern hashval_t bitmap_hash (const_bitmap);
304
305/* Allocate a bitmap from a bit obstack.  */
306#define BITMAP_ALLOC(OBSTACK) bitmap_obstack_alloc (OBSTACK)
307
308/* Allocate a gc'd bitmap.  */
309#define BITMAP_GGC_ALLOC() bitmap_gc_alloc ()
310
311/* Do any cleanup needed on a bitmap when it is no longer used.  */
312#define BITMAP_FREE(BITMAP) \
313       ((void) (bitmap_obstack_free ((bitmap) BITMAP), (BITMAP) = (bitmap) NULL))
314
315/* Iterator for bitmaps.  */
316
317struct bitmap_iterator
318{
319  /* Pointer to the current bitmap element.  */
320  bitmap_element *elt1;
321
322  /* Pointer to 2nd bitmap element when two are involved.  */
323  bitmap_element *elt2;
324
325  /* Word within the current element.  */
326  unsigned word_no;
327
328  /* Contents of the actually processed word.  When finding next bit
329     it is shifted right, so that the actual bit is always the least
330     significant bit of ACTUAL.  */
331  BITMAP_WORD bits;
332};
333
334/* Initialize a single bitmap iterator.  START_BIT is the first bit to
335   iterate from.  */
336
337static inline void
338bmp_iter_set_init (bitmap_iterator *bi, const_bitmap map,
339		   unsigned start_bit, unsigned *bit_no)
340{
341  bi->elt1 = map->first;
342  bi->elt2 = NULL;
343
344  /* Advance elt1 until it is not before the block containing start_bit.  */
345  while (1)
346    {
347      if (!bi->elt1)
348	{
349	  bi->elt1 = &bitmap_zero_bits;
350	  break;
351	}
352
353      if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
354	break;
355      bi->elt1 = bi->elt1->next;
356    }
357
358  /* We might have gone past the start bit, so reinitialize it.  */
359  if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
360    start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
361
362  /* Initialize for what is now start_bit.  */
363  bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
364  bi->bits = bi->elt1->bits[bi->word_no];
365  bi->bits >>= start_bit % BITMAP_WORD_BITS;
366
367  /* If this word is zero, we must make sure we're not pointing at the
368     first bit, otherwise our incrementing to the next word boundary
369     will fail.  It won't matter if this increment moves us into the
370     next word.  */
371  start_bit += !bi->bits;
372
373  *bit_no = start_bit;
374}
375
376/* Initialize an iterator to iterate over the intersection of two
377   bitmaps.  START_BIT is the bit to commence from.  */
378
379static inline void
380bmp_iter_and_init (bitmap_iterator *bi, const_bitmap map1, const_bitmap map2,
381		   unsigned start_bit, unsigned *bit_no)
382{
383  bi->elt1 = map1->first;
384  bi->elt2 = map2->first;
385
386  /* Advance elt1 until it is not before the block containing
387     start_bit.  */
388  while (1)
389    {
390      if (!bi->elt1)
391	{
392	  bi->elt2 = NULL;
393	  break;
394	}
395
396      if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
397	break;
398      bi->elt1 = bi->elt1->next;
399    }
400
401  /* Advance elt2 until it is not before elt1.  */
402  while (1)
403    {
404      if (!bi->elt2)
405	{
406	  bi->elt1 = bi->elt2 = &bitmap_zero_bits;
407	  break;
408	}
409
410      if (bi->elt2->indx >= bi->elt1->indx)
411	break;
412      bi->elt2 = bi->elt2->next;
413    }
414
415  /* If we're at the same index, then we have some intersecting bits.  */
416  if (bi->elt1->indx == bi->elt2->indx)
417    {
418      /* We might have advanced beyond the start_bit, so reinitialize
419	 for that.  */
420      if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
421	start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
422
423      bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
424      bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
425      bi->bits >>= start_bit % BITMAP_WORD_BITS;
426    }
427  else
428    {
429      /* Otherwise we must immediately advance elt1, so initialize for
430	 that.  */
431      bi->word_no = BITMAP_ELEMENT_WORDS - 1;
432      bi->bits = 0;
433    }
434
435  /* If this word is zero, we must make sure we're not pointing at the
436     first bit, otherwise our incrementing to the next word boundary
437     will fail.  It won't matter if this increment moves us into the
438     next word.  */
439  start_bit += !bi->bits;
440
441  *bit_no = start_bit;
442}
443
444/* Initialize an iterator to iterate over the bits in MAP1 & ~MAP2.
445   */
446
447static inline void
448bmp_iter_and_compl_init (bitmap_iterator *bi,
449			 const_bitmap map1, const_bitmap map2,
450			 unsigned start_bit, unsigned *bit_no)
451{
452  bi->elt1 = map1->first;
453  bi->elt2 = map2->first;
454
455  /* Advance elt1 until it is not before the block containing start_bit.  */
456  while (1)
457    {
458      if (!bi->elt1)
459	{
460	  bi->elt1 = &bitmap_zero_bits;
461	  break;
462	}
463
464      if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
465	break;
466      bi->elt1 = bi->elt1->next;
467    }
468
469  /* Advance elt2 until it is not before elt1.  */
470  while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
471    bi->elt2 = bi->elt2->next;
472
473  /* We might have advanced beyond the start_bit, so reinitialize for
474     that.  */
475  if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
476    start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
477
478  bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
479  bi->bits = bi->elt1->bits[bi->word_no];
480  if (bi->elt2 && bi->elt1->indx == bi->elt2->indx)
481    bi->bits &= ~bi->elt2->bits[bi->word_no];
482  bi->bits >>= start_bit % BITMAP_WORD_BITS;
483
484  /* If this word is zero, we must make sure we're not pointing at the
485     first bit, otherwise our incrementing to the next word boundary
486     will fail.  It won't matter if this increment moves us into the
487     next word.  */
488  start_bit += !bi->bits;
489
490  *bit_no = start_bit;
491}
492
493/* Advance to the next bit in BI.  We don't advance to the next
494   nonzero bit yet.  */
495
496static inline void
497bmp_iter_next (bitmap_iterator *bi, unsigned *bit_no)
498{
499  bi->bits >>= 1;
500  *bit_no += 1;
501}
502
503/* Advance to first set bit in BI.  */
504
505static inline void
506bmp_iter_next_bit (bitmap_iterator * bi, unsigned *bit_no)
507{
508#if (GCC_VERSION >= 3004)
509  {
510    unsigned int n = __builtin_ctzl (bi->bits);
511    gcc_assert (sizeof (unsigned long) == sizeof (BITMAP_WORD));
512    bi->bits >>= n;
513    *bit_no += n;
514  }
515#else
516  while (!(bi->bits & 1))
517    {
518      bi->bits >>= 1;
519      *bit_no += 1;
520    }
521#endif
522}
523
524/* Advance to the next nonzero bit of a single bitmap, we will have
525   already advanced past the just iterated bit.  Return true if there
526   is a bit to iterate.  */
527
528static inline bool
529bmp_iter_set (bitmap_iterator *bi, unsigned *bit_no)
530{
531  /* If our current word is nonzero, it contains the bit we want.  */
532  if (bi->bits)
533    {
534    next_bit:
535      bmp_iter_next_bit (bi, bit_no);
536      return true;
537    }
538
539  /* Round up to the word boundary.  We might have just iterated past
540     the end of the last word, hence the -1.  It is not possible for
541     bit_no to point at the beginning of the now last word.  */
542  *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
543	     / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
544  bi->word_no++;
545
546  while (1)
547    {
548      /* Find the next nonzero word in this elt.  */
549      while (bi->word_no != BITMAP_ELEMENT_WORDS)
550	{
551	  bi->bits = bi->elt1->bits[bi->word_no];
552	  if (bi->bits)
553	    goto next_bit;
554	  *bit_no += BITMAP_WORD_BITS;
555	  bi->word_no++;
556	}
557
558      /* Advance to the next element.  */
559      bi->elt1 = bi->elt1->next;
560      if (!bi->elt1)
561	return false;
562      *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
563      bi->word_no = 0;
564    }
565}
566
567/* Advance to the next nonzero bit of an intersecting pair of
568   bitmaps.  We will have already advanced past the just iterated bit.
569   Return true if there is a bit to iterate.  */
570
571static inline bool
572bmp_iter_and (bitmap_iterator *bi, unsigned *bit_no)
573{
574  /* If our current word is nonzero, it contains the bit we want.  */
575  if (bi->bits)
576    {
577    next_bit:
578      bmp_iter_next_bit (bi, bit_no);
579      return true;
580    }
581
582  /* Round up to the word boundary.  We might have just iterated past
583     the end of the last word, hence the -1.  It is not possible for
584     bit_no to point at the beginning of the now last word.  */
585  *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
586	     / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
587  bi->word_no++;
588
589  while (1)
590    {
591      /* Find the next nonzero word in this elt.  */
592      while (bi->word_no != BITMAP_ELEMENT_WORDS)
593	{
594	  bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
595	  if (bi->bits)
596	    goto next_bit;
597	  *bit_no += BITMAP_WORD_BITS;
598	  bi->word_no++;
599	}
600
601      /* Advance to the next identical element.  */
602      do
603	{
604	  /* Advance elt1 while it is less than elt2.  We always want
605	     to advance one elt.  */
606	  do
607	    {
608	      bi->elt1 = bi->elt1->next;
609	      if (!bi->elt1)
610		return false;
611	    }
612	  while (bi->elt1->indx < bi->elt2->indx);
613
614	  /* Advance elt2 to be no less than elt1.  This might not
615	     advance.  */
616	  while (bi->elt2->indx < bi->elt1->indx)
617	    {
618	      bi->elt2 = bi->elt2->next;
619	      if (!bi->elt2)
620		return false;
621	    }
622	}
623      while (bi->elt1->indx != bi->elt2->indx);
624
625      *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
626      bi->word_no = 0;
627    }
628}
629
630/* Advance to the next nonzero bit in the intersection of
631   complemented bitmaps.  We will have already advanced past the just
632   iterated bit.  */
633
634static inline bool
635bmp_iter_and_compl (bitmap_iterator *bi, unsigned *bit_no)
636{
637  /* If our current word is nonzero, it contains the bit we want.  */
638  if (bi->bits)
639    {
640    next_bit:
641      bmp_iter_next_bit (bi, bit_no);
642      return true;
643    }
644
645  /* Round up to the word boundary.  We might have just iterated past
646     the end of the last word, hence the -1.  It is not possible for
647     bit_no to point at the beginning of the now last word.  */
648  *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
649	     / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
650  bi->word_no++;
651
652  while (1)
653    {
654      /* Find the next nonzero word in this elt.  */
655      while (bi->word_no != BITMAP_ELEMENT_WORDS)
656	{
657	  bi->bits = bi->elt1->bits[bi->word_no];
658	  if (bi->elt2 && bi->elt2->indx == bi->elt1->indx)
659	    bi->bits &= ~bi->elt2->bits[bi->word_no];
660	  if (bi->bits)
661	    goto next_bit;
662	  *bit_no += BITMAP_WORD_BITS;
663	  bi->word_no++;
664	}
665
666      /* Advance to the next element of elt1.  */
667      bi->elt1 = bi->elt1->next;
668      if (!bi->elt1)
669	return false;
670
671      /* Advance elt2 until it is no less than elt1.  */
672      while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
673	bi->elt2 = bi->elt2->next;
674
675      *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
676      bi->word_no = 0;
677    }
678}
679
680/* Loop over all bits set in BITMAP, starting with MIN and setting
681   BITNUM to the bit number.  ITER is a bitmap iterator.  BITNUM
682   should be treated as a read-only variable as it contains loop
683   state.  */
684
685#ifndef EXECUTE_IF_SET_IN_BITMAP
686/* See sbitmap.h for the other definition of EXECUTE_IF_SET_IN_BITMAP.  */
687#define EXECUTE_IF_SET_IN_BITMAP(BITMAP, MIN, BITNUM, ITER)		\
688  for (bmp_iter_set_init (&(ITER), (BITMAP), (MIN), &(BITNUM));		\
689       bmp_iter_set (&(ITER), &(BITNUM));				\
690       bmp_iter_next (&(ITER), &(BITNUM)))
691#endif
692
693/* Loop over all the bits set in BITMAP1 & BITMAP2, starting with MIN
694   and setting BITNUM to the bit number.  ITER is a bitmap iterator.
695   BITNUM should be treated as a read-only variable as it contains
696   loop state.  */
697
698#define EXECUTE_IF_AND_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER)	\
699  for (bmp_iter_and_init (&(ITER), (BITMAP1), (BITMAP2), (MIN),		\
700			  &(BITNUM));					\
701       bmp_iter_and (&(ITER), &(BITNUM));				\
702       bmp_iter_next (&(ITER), &(BITNUM)))
703
704/* Loop over all the bits set in BITMAP1 & ~BITMAP2, starting with MIN
705   and setting BITNUM to the bit number.  ITER is a bitmap iterator.
706   BITNUM should be treated as a read-only variable as it contains
707   loop state.  */
708
709#define EXECUTE_IF_AND_COMPL_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER) \
710  for (bmp_iter_and_compl_init (&(ITER), (BITMAP1), (BITMAP2), (MIN),	\
711				&(BITNUM));				\
712       bmp_iter_and_compl (&(ITER), &(BITNUM));				\
713       bmp_iter_next (&(ITER), &(BITNUM)))
714
715#endif /* GCC_BITMAP_H */
716