2004-02-19 David Daney <ddaney@avtrex.com>
[official-gcc.git] / gcc / bitmap.c
blobbffd9154aee374577be7c5fecb61c5a12424b5b2
1 /* Functions to support general ended bitmaps.
2 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2003
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tm.h"
26 #include "rtl.h"
27 #include "flags.h"
28 #include "obstack.h"
29 #include "ggc.h"
30 #include "bitmap.h"
32 /* Obstack to allocate bitmap elements from. */
33 static struct obstack bitmap_obstack;
34 static int bitmap_obstack_init = FALSE;
36 #ifndef INLINE
37 #ifndef __GNUC__
38 #define INLINE
39 #else
40 #define INLINE __inline__
41 #endif
42 #endif
44 /* Global data */
45 bitmap_element bitmap_zero_bits; /* An element of all zero bits. */
46 static bitmap_element *bitmap_free; /* Freelist of bitmap elements. */
47 static GTY((deletable (""))) bitmap_element *bitmap_ggc_free;
49 static void bitmap_elem_to_freelist (bitmap, bitmap_element *);
50 static void bitmap_element_free (bitmap, bitmap_element *);
51 static bitmap_element *bitmap_element_allocate (bitmap);
52 static int bitmap_element_zerop (bitmap_element *);
53 static void bitmap_element_link (bitmap, bitmap_element *);
54 static bitmap_element *bitmap_find_bit (bitmap, unsigned int);
56 /* Add ELEM to the appropriate freelist. */
57 static INLINE void
58 bitmap_elem_to_freelist (bitmap head, bitmap_element *elt)
60 if (head->using_obstack)
62 elt->next = bitmap_free;
63 bitmap_free = elt;
65 else
67 elt->next = bitmap_ggc_free;
68 bitmap_ggc_free = elt;
72 /* Free a bitmap element. Since these are allocated off the
73 bitmap_obstack, "free" actually means "put onto the freelist". */
75 static INLINE void
76 bitmap_element_free (bitmap head, bitmap_element *elt)
78 bitmap_element *next = elt->next;
79 bitmap_element *prev = elt->prev;
81 if (prev)
82 prev->next = next;
84 if (next)
85 next->prev = prev;
87 if (head->first == elt)
88 head->first = next;
90 /* Since the first thing we try is to insert before current,
91 make current the next entry in preference to the previous. */
92 if (head->current == elt)
94 head->current = next != 0 ? next : prev;
95 if (head->current)
96 head->indx = head->current->indx;
98 bitmap_elem_to_freelist (head, elt);
101 /* Allocate a bitmap element. The bits are cleared, but nothing else is. */
103 static INLINE bitmap_element *
104 bitmap_element_allocate (bitmap head)
106 bitmap_element *element;
108 if (head->using_obstack)
110 if (bitmap_free != 0)
112 element = bitmap_free;
113 bitmap_free = element->next;
115 else
117 /* We can't use gcc_obstack_init to initialize the obstack since
118 print-rtl.c now calls bitmap functions, and bitmap is linked
119 into the gen* functions. */
120 if (!bitmap_obstack_init)
122 bitmap_obstack_init = TRUE;
124 #if !defined(__GNUC__) || (__GNUC__ < 2)
125 #define __alignof__(type) 0
126 #endif
128 obstack_specify_allocation (&bitmap_obstack, OBSTACK_CHUNK_SIZE,
129 __alignof__ (bitmap_element),
130 obstack_chunk_alloc,
131 obstack_chunk_free);
134 element = obstack_alloc (&bitmap_obstack, sizeof (bitmap_element));
137 else
139 if (bitmap_ggc_free != NULL)
141 element = bitmap_ggc_free;
142 bitmap_ggc_free = element->next;
144 else
145 element = ggc_alloc (sizeof (bitmap_element));
148 memset (element->bits, 0, sizeof (element->bits));
150 return element;
153 /* Release any memory allocated by bitmaps. */
155 void
156 bitmap_release_memory (void)
158 bitmap_free = 0;
159 if (bitmap_obstack_init)
161 bitmap_obstack_init = FALSE;
162 obstack_free (&bitmap_obstack, NULL);
166 /* Return nonzero if all bits in an element are zero. */
168 static INLINE int
169 bitmap_element_zerop (bitmap_element *element)
171 #if BITMAP_ELEMENT_WORDS == 2
172 return (element->bits[0] | element->bits[1]) == 0;
173 #else
174 int i;
176 for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
177 if (element->bits[i] != 0)
178 return 0;
180 return 1;
181 #endif
184 /* Link the bitmap element into the current bitmap linked list. */
186 static INLINE void
187 bitmap_element_link (bitmap head, bitmap_element *element)
189 unsigned int indx = element->indx;
190 bitmap_element *ptr;
192 /* If this is the first and only element, set it in. */
193 if (head->first == 0)
195 element->next = element->prev = 0;
196 head->first = element;
199 /* If this index is less than that of the current element, it goes someplace
200 before the current element. */
201 else if (indx < head->indx)
203 for (ptr = head->current;
204 ptr->prev != 0 && ptr->prev->indx > indx;
205 ptr = ptr->prev)
208 if (ptr->prev)
209 ptr->prev->next = element;
210 else
211 head->first = element;
213 element->prev = ptr->prev;
214 element->next = ptr;
215 ptr->prev = element;
218 /* Otherwise, it must go someplace after the current element. */
219 else
221 for (ptr = head->current;
222 ptr->next != 0 && ptr->next->indx < indx;
223 ptr = ptr->next)
226 if (ptr->next)
227 ptr->next->prev = element;
229 element->next = ptr->next;
230 element->prev = ptr;
231 ptr->next = element;
234 /* Set up so this is the first element searched. */
235 head->current = element;
236 head->indx = indx;
239 /* Clear a bitmap by freeing the linked list. */
241 INLINE void
242 bitmap_clear (bitmap head)
244 bitmap_element *element, *next;
246 for (element = head->first; element != 0; element = next)
248 next = element->next;
249 bitmap_elem_to_freelist (head, element);
252 head->first = head->current = 0;
255 /* Copy a bitmap to another bitmap. */
257 void
258 bitmap_copy (bitmap to, bitmap from)
260 bitmap_element *from_ptr, *to_ptr = 0;
261 #if BITMAP_ELEMENT_WORDS != 2
262 int i;
263 #endif
265 bitmap_clear (to);
267 /* Copy elements in forward direction one at a time. */
268 for (from_ptr = from->first; from_ptr; from_ptr = from_ptr->next)
270 bitmap_element *to_elt = bitmap_element_allocate (to);
272 to_elt->indx = from_ptr->indx;
274 #if BITMAP_ELEMENT_WORDS == 2
275 to_elt->bits[0] = from_ptr->bits[0];
276 to_elt->bits[1] = from_ptr->bits[1];
277 #else
278 for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
279 to_elt->bits[i] = from_ptr->bits[i];
280 #endif
282 /* Here we have a special case of bitmap_element_link, for the case
283 where we know the links are being entered in sequence. */
284 if (to_ptr == 0)
286 to->first = to->current = to_elt;
287 to->indx = from_ptr->indx;
288 to_elt->next = to_elt->prev = 0;
290 else
292 to_elt->prev = to_ptr;
293 to_elt->next = 0;
294 to_ptr->next = to_elt;
297 to_ptr = to_elt;
301 /* Find a bitmap element that would hold a bitmap's bit.
302 Update the `current' field even if we can't find an element that
303 would hold the bitmap's bit to make eventual allocation
304 faster. */
306 static INLINE bitmap_element *
307 bitmap_find_bit (bitmap head, unsigned int bit)
309 bitmap_element *element;
310 unsigned int indx = bit / BITMAP_ELEMENT_ALL_BITS;
312 if (head->current == 0
313 || head->indx == indx)
314 return head->current;
316 if (head->indx > indx)
317 for (element = head->current;
318 element->prev != 0 && element->indx > indx;
319 element = element->prev)
322 else
323 for (element = head->current;
324 element->next != 0 && element->indx < indx;
325 element = element->next)
328 /* `element' is the nearest to the one we want. If it's not the one we
329 want, the one we want doesn't exist. */
330 head->current = element;
331 head->indx = element->indx;
332 if (element != 0 && element->indx != indx)
333 element = 0;
335 return element;
338 /* Clear a single bit in a bitmap. */
340 void
341 bitmap_clear_bit (bitmap head, int bit)
343 bitmap_element *ptr = bitmap_find_bit (head, bit);
345 if (ptr != 0)
347 unsigned bit_num = bit % BITMAP_WORD_BITS;
348 unsigned word_num = bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
349 ptr->bits[word_num] &= ~ (((BITMAP_WORD) 1) << bit_num);
351 /* If we cleared the entire word, free up the element. */
352 if (bitmap_element_zerop (ptr))
353 bitmap_element_free (head, ptr);
357 /* Set a single bit in a bitmap. */
359 void
360 bitmap_set_bit (bitmap head, int bit)
362 bitmap_element *ptr = bitmap_find_bit (head, bit);
363 unsigned word_num = bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
364 unsigned bit_num = bit % BITMAP_WORD_BITS;
365 BITMAP_WORD bit_val = ((BITMAP_WORD) 1) << bit_num;
367 if (ptr == 0)
369 ptr = bitmap_element_allocate (head);
370 ptr->indx = bit / BITMAP_ELEMENT_ALL_BITS;
371 ptr->bits[word_num] = bit_val;
372 bitmap_element_link (head, ptr);
374 else
375 ptr->bits[word_num] |= bit_val;
378 /* Return whether a bit is set within a bitmap. */
381 bitmap_bit_p (bitmap head, int bit)
383 bitmap_element *ptr;
384 unsigned bit_num;
385 unsigned word_num;
387 ptr = bitmap_find_bit (head, bit);
388 if (ptr == 0)
389 return 0;
391 bit_num = bit % BITMAP_WORD_BITS;
392 word_num = bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
394 return (ptr->bits[word_num] >> bit_num) & 1;
397 /* Return the bit number of the first set bit in the bitmap, or -1
398 if the bitmap is empty. */
401 bitmap_first_set_bit (bitmap a)
403 bitmap_element *ptr = a->first;
404 BITMAP_WORD word;
405 unsigned word_num, bit_num;
407 if (ptr == NULL)
408 return -1;
410 #if BITMAP_ELEMENT_WORDS == 2
411 word_num = 0, word = ptr->bits[0];
412 if (word == 0)
413 word_num = 1, word = ptr->bits[1];
414 #else
415 for (word_num = 0; word_num < BITMAP_ELEMENT_WORDS; ++word_num)
416 if ((word = ptr->bits[word_num]) != 0)
417 break;
418 #endif
420 /* Binary search for the first set bit. */
421 /* ??? It'd be nice to know if ffs or ffsl was available. */
423 bit_num = 0;
424 word = word & -word;
426 #if nBITMAP_WORD_BITS > 64
427 #error "Fill out the table."
428 #endif
429 #if nBITMAP_WORD_BITS > 32
430 if ((word & 0xffffffff) == 0)
431 word >>= 32, bit_num += 32;
432 #endif
433 if ((word & 0xffff) == 0)
434 word >>= 16, bit_num += 16;
435 if ((word & 0xff) == 0)
436 word >>= 8, bit_num += 8;
437 if (word & 0xf0)
438 bit_num += 4;
439 if (word & 0xcc)
440 bit_num += 2;
441 if (word & 0xaa)
442 bit_num += 1;
444 return (ptr->indx * BITMAP_ELEMENT_ALL_BITS
445 + word_num * BITMAP_WORD_BITS
446 + bit_num);
449 /* Return the bit number of the last set bit in the bitmap, or -1
450 if the bitmap is empty. */
453 bitmap_last_set_bit (bitmap a)
455 bitmap_element *ptr = a->first;
456 BITMAP_WORD word;
457 unsigned word_num, bit_num;
459 if (ptr == NULL)
460 return -1;
462 while (ptr->next != NULL)
463 ptr = ptr->next;
465 #if BITMAP_ELEMENT_WORDS == 2
466 word_num = 1, word = ptr->bits[1];
467 if (word == 0)
468 word_num = 0, word = ptr->bits[0];
469 #else
470 for (word_num = BITMAP_ELEMENT_WORDS; word_num-- > 0; )
471 if ((word = ptr->bits[word_num]) != 0)
472 break;
473 #endif
475 /* Binary search for the last set bit. */
477 bit_num = 0;
478 #if nBITMAP_WORD_BITS > 64
479 #error "Fill out the table."
480 #endif
481 #if nBITMAP_WORD_BITS > 32
482 if (word & ~(BITMAP_WORD)0xffffffff)
483 word >>= 32, bit_num += 32;
484 #endif
485 if (word & 0xffff0000)
486 word >>= 16, bit_num += 16;
487 if (word & 0xff00)
488 word >>= 8, bit_num += 8;
489 if (word & 0xf0)
490 word >>= 4, bit_num += 4;
491 if (word & 0xc)
492 word >>= 2, bit_num += 2;
493 if (word & 0x2)
494 bit_num += 1;
496 return (ptr->indx * BITMAP_ELEMENT_ALL_BITS
497 + word_num * BITMAP_WORD_BITS
498 + bit_num);
501 /* Store in bitmap TO the result of combining bitmap FROM1 and FROM2 using
502 a specific bit manipulation. Return true if TO changes. */
505 bitmap_operation (bitmap to, bitmap from1, bitmap from2,
506 enum bitmap_bits operation)
508 #define HIGHEST_INDEX (unsigned int) ~0
510 bitmap_element *from1_ptr = from1->first;
511 bitmap_element *from2_ptr = from2->first;
512 unsigned int indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
513 unsigned int indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
514 bitmap_element *to_ptr = to->first;
515 bitmap_element *from1_tmp;
516 bitmap_element *from2_tmp;
517 bitmap_element *to_tmp;
518 unsigned int indx;
519 int changed = 0;
521 #if BITMAP_ELEMENT_WORDS == 2
522 #define DOIT(OP) \
523 do { \
524 BITMAP_WORD t0, t1, f10, f11, f20, f21; \
525 f10 = from1_tmp->bits[0]; \
526 f20 = from2_tmp->bits[0]; \
527 t0 = f10 OP f20; \
528 changed |= (t0 != to_tmp->bits[0]); \
529 f11 = from1_tmp->bits[1]; \
530 f21 = from2_tmp->bits[1]; \
531 t1 = f11 OP f21; \
532 changed |= (t1 != to_tmp->bits[1]); \
533 to_tmp->bits[0] = t0; \
534 to_tmp->bits[1] = t1; \
535 } while (0)
536 #else
537 #define DOIT(OP) \
538 do { \
539 BITMAP_WORD t, f1, f2; \
540 int i; \
541 for (i = 0; i < BITMAP_ELEMENT_WORDS; ++i) \
543 f1 = from1_tmp->bits[i]; \
544 f2 = from2_tmp->bits[i]; \
545 t = f1 OP f2; \
546 changed |= (t != to_tmp->bits[i]); \
547 to_tmp->bits[i] = t; \
549 } while (0)
550 #endif
552 to->first = to->current = 0;
554 while (from1_ptr != 0 || from2_ptr != 0)
556 /* Figure out whether we need to substitute zero elements for
557 missing links. */
558 if (indx1 == indx2)
560 indx = indx1;
561 from1_tmp = from1_ptr;
562 from2_tmp = from2_ptr;
563 from1_ptr = from1_ptr->next;
564 indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
565 from2_ptr = from2_ptr->next;
566 indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
568 else if (indx1 < indx2)
570 indx = indx1;
571 from1_tmp = from1_ptr;
572 from2_tmp = &bitmap_zero_bits;
573 from1_ptr = from1_ptr->next;
574 indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
576 else
578 indx = indx2;
579 from1_tmp = &bitmap_zero_bits;
580 from2_tmp = from2_ptr;
581 from2_ptr = from2_ptr->next;
582 indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
585 /* Find the appropriate element from TO. Begin by discarding
586 elements that we've skipped. */
587 while (to_ptr && to_ptr->indx < indx)
589 changed = 1;
590 to_tmp = to_ptr;
591 to_ptr = to_ptr->next;
592 bitmap_elem_to_freelist (to, to_tmp);
594 if (to_ptr && to_ptr->indx == indx)
596 to_tmp = to_ptr;
597 to_ptr = to_ptr->next;
599 else
600 to_tmp = bitmap_element_allocate (to);
602 /* Do the operation, and if any bits are set, link it into the
603 linked list. */
604 switch (operation)
606 default:
607 abort ();
609 case BITMAP_AND:
610 DOIT (&);
611 break;
613 case BITMAP_AND_COMPL:
614 DOIT (&~);
615 break;
617 case BITMAP_IOR:
618 DOIT (|);
619 break;
620 case BITMAP_IOR_COMPL:
621 DOIT (|~);
622 break;
623 case BITMAP_XOR:
624 DOIT (^);
625 break;
628 if (! bitmap_element_zerop (to_tmp))
630 to_tmp->indx = indx;
631 bitmap_element_link (to, to_tmp);
633 else
635 bitmap_elem_to_freelist (to, to_tmp);
639 /* If we have elements of TO left over, free the lot. */
640 if (to_ptr)
642 changed = 1;
643 for (to_tmp = to_ptr; to_tmp->next ; to_tmp = to_tmp->next)
644 continue;
645 if (to->using_obstack)
647 to_tmp->next = bitmap_free;
648 bitmap_free = to_ptr;
650 else
652 to_tmp->next = bitmap_ggc_free;
653 bitmap_ggc_free = to_ptr;
657 #undef DOIT
659 return changed;
662 /* Return true if two bitmaps are identical. */
665 bitmap_equal_p (bitmap a, bitmap b)
667 bitmap_head c;
668 int ret;
670 memset (&c, 0, sizeof (c));
671 ret = ! bitmap_operation (&c, a, b, BITMAP_XOR);
672 bitmap_clear (&c);
674 return ret;
677 /* Or into bitmap TO bitmap FROM1 and'ed with the complement of
678 bitmap FROM2. */
680 void
681 bitmap_ior_and_compl (bitmap to, bitmap from1, bitmap from2)
683 bitmap_head tmp;
685 tmp.first = tmp.current = 0;
686 tmp.using_obstack = 0;
688 bitmap_operation (&tmp, from1, from2, BITMAP_AND_COMPL);
689 bitmap_operation (to, to, &tmp, BITMAP_IOR);
690 bitmap_clear (&tmp);
694 bitmap_union_of_diff (bitmap dst, bitmap a, bitmap b, bitmap c)
696 bitmap_head tmp;
697 int changed;
699 tmp.first = tmp.current = 0;
700 tmp.using_obstack = 0;
702 bitmap_operation (&tmp, b, c, BITMAP_AND_COMPL);
703 changed = bitmap_operation (dst, &tmp, a, BITMAP_IOR);
704 bitmap_clear (&tmp);
706 return changed;
709 /* Initialize a bitmap header. */
711 bitmap
712 bitmap_initialize (bitmap head, int using_obstack)
714 if (head == NULL && ! using_obstack)
715 head = ggc_alloc (sizeof (*head));
717 head->first = head->current = 0;
718 head->using_obstack = using_obstack;
720 return head;
723 /* Debugging function to print out the contents of a bitmap. */
725 void
726 debug_bitmap_file (FILE *file, bitmap head)
728 bitmap_element *ptr;
730 fprintf (file, "\nfirst = " HOST_PTR_PRINTF
731 " current = " HOST_PTR_PRINTF " indx = %u\n",
732 (void *) head->first, (void *) head->current, head->indx);
734 for (ptr = head->first; ptr; ptr = ptr->next)
736 unsigned int i, j, col = 26;
738 fprintf (file, "\t" HOST_PTR_PRINTF " next = " HOST_PTR_PRINTF
739 " prev = " HOST_PTR_PRINTF " indx = %u\n\t\tbits = {",
740 (void*) ptr, (void*) ptr->next, (void*) ptr->prev, ptr->indx);
742 for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
743 for (j = 0; j < BITMAP_WORD_BITS; j++)
744 if ((ptr->bits[i] >> j) & 1)
746 if (col > 70)
748 fprintf (file, "\n\t\t\t");
749 col = 24;
752 fprintf (file, " %u", (ptr->indx * BITMAP_ELEMENT_ALL_BITS
753 + i * BITMAP_WORD_BITS + j));
754 col += 4;
757 fprintf (file, " }\n");
761 /* Function to be called from the debugger to print the contents
762 of a bitmap. */
764 void
765 debug_bitmap (bitmap head)
767 debug_bitmap_file (stdout, head);
770 /* Function to print out the contents of a bitmap. Unlike debug_bitmap_file,
771 it does not print anything but the bits. */
773 void
774 bitmap_print (FILE *file, bitmap head, const char *prefix, const char *suffix)
776 const char *comma = "";
777 int i;
779 fputs (prefix, file);
780 EXECUTE_IF_SET_IN_BITMAP (head, 0, i,
782 fprintf (file, "%s%d", comma, i);
783 comma = ", ";
785 fputs (suffix, file);
788 #include "gt-bitmap.h"