gcc/bitmap.c

   1 /* Functions to support general ended bitmaps.
   2    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2003
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   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.
  11
  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.
  16
  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.  */
  21
  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"
  31
  32 /* Obstack to allocate bitmap elements from.  */
  33 static struct obstack bitmap_obstack;
  34 static int bitmap_obstack_init = FALSE;
  35 \f
  36 #ifndef INLINE
  37 #ifndef __GNUC__
  38 #define INLINE
  39 #else
  40 #define INLINE __inline__
  41 #endif
  42 #endif
  43
  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;
  48
  49 static void bitmap_elem_to_freelist     PARAMS ((bitmap, bitmap_element *));
  50 static void bitmap_element_free         PARAMS ((bitmap, bitmap_element *));
  51 static bitmap_element *bitmap_element_allocate PARAMS ((bitmap));
  52 static int bitmap_element_zerop         PARAMS ((bitmap_element *));
  53 static void bitmap_element_link         PARAMS ((bitmap, bitmap_element *));
  54 static bitmap_element *bitmap_find_bit  PARAMS ((bitmap, unsigned int));
  55 \f
  56 /* Add ELEM to the appropriate freelist.  */
  57 static INLINE void
  58 bitmap_elem_to_freelist (head, elt)
  59      bitmap head;
  60      bitmap_element *elt;
  61 {
  62   if (head->using_obstack)
  63     {
  64       elt->next = bitmap_free;
  65       bitmap_free = elt;
  66     }
  67   else
  68     {
  69       elt->next = bitmap_ggc_free;
  70       bitmap_ggc_free = elt;
  71     }
  72 }
  73
  74 /* Free a bitmap element.  Since these are allocated off the
  75    bitmap_obstack, "free" actually means "put onto the freelist".  */
  76
  77 static INLINE void
  78 bitmap_element_free (head, elt)
  79      bitmap head;
  80      bitmap_element *elt;
  81 {
  82   bitmap_element *next = elt->next;
  83   bitmap_element *prev = elt->prev;
  84
  85   if (prev)
  86     prev->next = next;
  87
  88   if (next)
  89     next->prev = prev;
  90
  91   if (head->first == elt)
  92     head->first = next;
  93
  94   /* Since the first thing we try is to insert before current,
  95      make current the next entry in preference to the previous.  */
  96   if (head->current == elt)
  97     {
  98       head->current = next != 0 ? next : prev;
  99       if (head->current)
 100         head->indx = head->current->indx;
 101     }
 102   bitmap_elem_to_freelist (head, elt);
 103 }
 104 \f
 105 /* Allocate a bitmap element.  The bits are cleared, but nothing else is.  */
 106
 107 static INLINE bitmap_element *
 108 bitmap_element_allocate (head)
 109      bitmap head;
 110 {
 111   bitmap_element *element;
 112
 113   if (head->using_obstack)
 114     {
 115       if (bitmap_free != 0)
 116         {
 117           element = bitmap_free;
 118           bitmap_free = element->next;
 119         }
 120       else
 121         {
 122           /* We can't use gcc_obstack_init to initialize the obstack since
 123              print-rtl.c now calls bitmap functions, and bitmap is linked
 124              into the gen* functions.  */
 125           if (!bitmap_obstack_init)
 126             {
 127               bitmap_obstack_init = TRUE;
 128
 129               /* Let particular systems override the size of a chunk.  */
 130 #ifndef OBSTACK_CHUNK_SIZE
 131 #define OBSTACK_CHUNK_SIZE 0
 132 #endif
 133               /* Let them override the alloc and free routines too.  */
 134 #ifndef OBSTACK_CHUNK_ALLOC
 135 #define OBSTACK_CHUNK_ALLOC xmalloc
 136 #endif
 137 #ifndef OBSTACK_CHUNK_FREE
 138 #define OBSTACK_CHUNK_FREE free
 139 #endif
 140
 141 #if !defined(__GNUC__) || (__GNUC__ < 2)
 142 #define __alignof__(type) 0
 143 #endif
 144
 145               obstack_specify_allocation (&bitmap_obstack, OBSTACK_CHUNK_SIZE,
 146                                           __alignof__ (bitmap_element),
 147                                           (void *(*) PARAMS ((long))) OBSTACK_CHUNK_ALLOC,
 148                                           (void (*) PARAMS ((void *))) OBSTACK_CHUNK_FREE);
 149             }
 150
 151           element = (bitmap_element *) obstack_alloc (&bitmap_obstack,
 152                                                       sizeof (bitmap_element));
 153         }
 154     }
 155   else
 156     {
 157       if (bitmap_ggc_free != NULL)
 158         {
 159           element = bitmap_ggc_free;
 160           bitmap_ggc_free = element->next;
 161         }
 162       else
 163         element = ggc_alloc (sizeof (bitmap_element));
 164     }
 165
 166   memset (element->bits, 0, sizeof (element->bits));
 167
 168   return element;
 169 }
 170
 171 /* Release any memory allocated by bitmaps.  */
 172
 173 void
 174 bitmap_release_memory ()
 175 {
 176   bitmap_free = 0;
 177   if (bitmap_obstack_init)
 178     {
 179       bitmap_obstack_init = FALSE;
 180       obstack_free (&bitmap_obstack, NULL);
 181     }
 182 }
 183
 184 /* Return nonzero if all bits in an element are zero.  */
 185
 186 static INLINE int
 187 bitmap_element_zerop (element)
 188      bitmap_element *element;
 189 {
 190 #if BITMAP_ELEMENT_WORDS == 2
 191   return (element->bits[0] | element->bits[1]) == 0;
 192 #else
 193   int i;
 194
 195   for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
 196     if (element->bits[i] != 0)
 197       return 0;
 198
 199   return 1;
 200 #endif
 201 }
 202 \f
 203 /* Link the bitmap element into the current bitmap linked list.  */
 204
 205 static INLINE void
 206 bitmap_element_link (head, element)
 207      bitmap head;
 208      bitmap_element *element;
 209 {
 210   unsigned int indx = element->indx;
 211   bitmap_element *ptr;
 212
 213   /* If this is the first and only element, set it in.  */
 214   if (head->first == 0)
 215     {
 216       element->next = element->prev = 0;
 217       head->first = element;
 218     }
 219
 220   /* If this index is less than that of the current element, it goes someplace
 221      before the current element.  */
 222   else if (indx < head->indx)
 223     {
 224       for (ptr = head->current;
 225            ptr->prev != 0 && ptr->prev->indx > indx;
 226            ptr = ptr->prev)
 227         ;
 228
 229       if (ptr->prev)
 230         ptr->prev->next = element;
 231       else
 232         head->first = element;
 233
 234       element->prev = ptr->prev;
 235       element->next = ptr;
 236       ptr->prev = element;
 237     }
 238
 239   /* Otherwise, it must go someplace after the current element.  */
 240   else
 241     {
 242       for (ptr = head->current;
 243            ptr->next != 0 && ptr->next->indx < indx;
 244            ptr = ptr->next)
 245         ;
 246
 247       if (ptr->next)
 248         ptr->next->prev = element;
 249
 250       element->next = ptr->next;
 251       element->prev = ptr;
 252       ptr->next = element;
 253     }
 254
 255   /* Set up so this is the first element searched.  */
 256   head->current = element;
 257   head->indx = indx;
 258 }
 259 \f
 260 /* Clear a bitmap by freeing the linked list.  */
 261
 262 INLINE void
 263 bitmap_clear (head)
 264      bitmap head;
 265 {
 266   bitmap_element *element, *next;
 267
 268   for (element = head->first; element != 0; element = next)
 269     {
 270       next = element->next;
 271       bitmap_elem_to_freelist (head, element);
 272     }
 273
 274   head->first = head->current = 0;
 275 }
 276 \f
 277 /* Copy a bitmap to another bitmap.  */
 278
 279 void
 280 bitmap_copy (to, from)
 281      bitmap to;
 282      bitmap from;
 283 {
 284   bitmap_element *from_ptr, *to_ptr = 0;
 285 #if BITMAP_ELEMENT_WORDS != 2
 286   int i;
 287 #endif
 288
 289   bitmap_clear (to);
 290
 291   /* Copy elements in forward direction one at a time */
 292   for (from_ptr = from->first; from_ptr; from_ptr = from_ptr->next)
 293     {
 294       bitmap_element *to_elt = bitmap_element_allocate (to);
 295
 296       to_elt->indx = from_ptr->indx;
 297
 298 #if BITMAP_ELEMENT_WORDS == 2
 299       to_elt->bits[0] = from_ptr->bits[0];
 300       to_elt->bits[1] = from_ptr->bits[1];
 301 #else
 302       for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
 303         to_elt->bits[i] = from_ptr->bits[i];
 304 #endif
 305
 306       /* Here we have a special case of bitmap_element_link, for the case
 307          where we know the links are being entered in sequence.  */
 308       if (to_ptr == 0)
 309         {
 310           to->first = to->current = to_elt;
 311           to->indx = from_ptr->indx;
 312           to_elt->next = to_elt->prev = 0;
 313         }
 314       else
 315         {
 316           to_elt->prev = to_ptr;
 317           to_elt->next = 0;
 318           to_ptr->next = to_elt;
 319         }
 320
 321       to_ptr = to_elt;
 322     }
 323 }
 324 \f
 325 /* Find a bitmap element that would hold a bitmap's bit.
 326    Update the `current' field even if we can't find an element that
 327    would hold the bitmap's bit to make eventual allocation
 328    faster.  */
 329
 330 static INLINE bitmap_element *
 331 bitmap_find_bit (head, bit)
 332      bitmap head;
 333      unsigned int bit;
 334 {
 335   bitmap_element *element;
 336   unsigned int indx = bit / BITMAP_ELEMENT_ALL_BITS;
 337
 338   if (head->current == 0
 339       || head->indx == indx)
 340     return head->current;
 341
 342   if (head->indx > indx)
 343     for (element = head->current;
 344          element->prev != 0 && element->indx > indx;
 345          element = element->prev)
 346       ;
 347
 348   else
 349     for (element = head->current;
 350          element->next != 0 && element->indx < indx;
 351          element = element->next)
 352       ;
 353
 354   /* `element' is the nearest to the one we want.  If it's not the one we
 355      want, the one we want doesn't exist.  */
 356   head->current = element;
 357   head->indx = element->indx;
 358   if (element != 0 && element->indx != indx)
 359     element = 0;
 360
 361   return element;
 362 }
 363 \f
 364 /* Clear a single bit in a bitmap.  */
 365
 366 void
 367 bitmap_clear_bit (head, bit)
 368      bitmap head;
 369      int bit;
 370 {
 371   bitmap_element *ptr = bitmap_find_bit (head, bit);
 372
 373   if (ptr != 0)
 374     {
 375       unsigned bit_num  = bit % BITMAP_WORD_BITS;
 376       unsigned word_num = bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
 377       ptr->bits[word_num] &= ~ (((BITMAP_WORD) 1) << bit_num);
 378
 379       /* If we cleared the entire word, free up the element */
 380       if (bitmap_element_zerop (ptr))
 381         bitmap_element_free (head, ptr);
 382     }
 383 }
 384
 385 /* Set a single bit in a bitmap.  */
 386
 387 void
 388 bitmap_set_bit (head, bit)
 389      bitmap head;
 390      int bit;
 391 {
 392   bitmap_element *ptr = bitmap_find_bit (head, bit);
 393   unsigned word_num = bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
 394   unsigned bit_num  = bit % BITMAP_WORD_BITS;
 395   BITMAP_WORD bit_val = ((BITMAP_WORD) 1) << bit_num;
 396
 397   if (ptr == 0)
 398     {
 399       ptr = bitmap_element_allocate (head);
 400       ptr->indx = bit / BITMAP_ELEMENT_ALL_BITS;
 401       ptr->bits[word_num] = bit_val;
 402       bitmap_element_link (head, ptr);
 403     }
 404   else
 405     ptr->bits[word_num] |= bit_val;
 406 }
 407
 408 /* Return whether a bit is set within a bitmap.  */
 409
 410 int
 411 bitmap_bit_p (head, bit)
 412      bitmap head;
 413      int bit;
 414 {
 415   bitmap_element *ptr;
 416   unsigned bit_num;
 417   unsigned word_num;
 418
 419   ptr = bitmap_find_bit (head, bit);
 420   if (ptr == 0)
 421     return 0;
 422
 423   bit_num = bit % BITMAP_WORD_BITS;
 424   word_num = bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
 425
 426   return (ptr->bits[word_num] >> bit_num) & 1;
 427 }
 428 \f
 429 /* Return the bit number of the first set bit in the bitmap, or -1
 430    if the bitmap is empty.  */
 431
 432 int
 433 bitmap_first_set_bit (a)
 434      bitmap a;
 435 {
 436   bitmap_element *ptr = a->first;
 437   BITMAP_WORD word;
 438   unsigned word_num, bit_num;
 439
 440   if (ptr == NULL)
 441     return -1;
 442
 443 #if BITMAP_ELEMENT_WORDS == 2
 444   word_num = 0, word = ptr->bits[0];
 445   if (word == 0)
 446     word_num = 1, word = ptr->bits[1];
 447 #else
 448   for (word_num = 0; word_num < BITMAP_ELEMENT_WORDS; ++word_num)
 449     if ((word = ptr->bits[word_num]) != 0)
 450       break;
 451 #endif
 452
 453   /* Binary search for the first set bit.  */
 454   /* ??? It'd be nice to know if ffs or ffsl was available.  */
 455
 456   bit_num = 0;
 457   word = word & -word;
 458
 459 #if nBITMAP_WORD_BITS > 64
 460  #error "Fill out the table."
 461 #endif
 462 #if nBITMAP_WORD_BITS > 32
 463   if ((word & 0xffffffff) == 0)
 464     word >>= 32, bit_num += 32;
 465 #endif
 466   if ((word & 0xffff) == 0)
 467     word >>= 16, bit_num += 16;
 468   if ((word & 0xff) == 0)
 469     word >>= 8, bit_num += 8;
 470   if (word & 0xf0)
 471     bit_num += 4;
 472   if (word & 0xcc)
 473     bit_num += 2;
 474   if (word & 0xaa)
 475     bit_num += 1;
 476
 477   return (ptr->indx * BITMAP_ELEMENT_ALL_BITS
 478           + word_num * BITMAP_WORD_BITS
 479           + bit_num);
 480 }
 481
 482 /* Return the bit number of the last set bit in the bitmap, or -1
 483    if the bitmap is empty.  */
 484
 485 int
 486 bitmap_last_set_bit (a)
 487      bitmap a;
 488 {
 489   bitmap_element *ptr = a->first;
 490   BITMAP_WORD word;
 491   unsigned word_num, bit_num;
 492
 493   if (ptr == NULL)
 494     return -1;
 495
 496   while (ptr->next != NULL)
 497     ptr = ptr->next;
 498
 499 #if BITMAP_ELEMENT_WORDS == 2
 500   word_num = 1, word = ptr->bits[1];
 501   if (word == 0)
 502     word_num = 0, word = ptr->bits[0];
 503 #else
 504   for (word_num = BITMAP_ELEMENT_WORDS; word_num-- > 0; )
 505     if ((word = ptr->bits[word_num]) != 0)
 506       break;
 507 #endif
 508
 509   /* Binary search for the last set bit.  */
 510
 511   bit_num = 0;
 512 #if nBITMAP_WORD_BITS > 64
 513  #error "Fill out the table."
 514 #endif
 515 #if nBITMAP_WORD_BITS > 32
 516   if (word & ~(BITMAP_WORD)0xffffffff)
 517     word >>= 32, bit_num += 32;
 518 #endif
 519   if (word & 0xffff0000)
 520     word >>= 16, bit_num += 16;
 521   if (word & 0xff00)
 522     word >>= 8, bit_num += 8;
 523   if (word & 0xf0)
 524     word >>= 4, bit_num += 4;
 525   if (word & 0xc)
 526     word >>= 2, bit_num += 2;
 527   if (word & 0x2)
 528     bit_num += 1;
 529
 530   return (ptr->indx * BITMAP_ELEMENT_ALL_BITS
 531           + word_num * BITMAP_WORD_BITS
 532           + bit_num);
 533 }
 534 \f
 535 /* Store in bitmap TO the result of combining bitmap FROM1 and FROM2 using
 536    a specific bit manipulation.  Return true if TO changes.  */
 537
 538 int
 539 bitmap_operation (to, from1, from2, operation)
 540      bitmap to;
 541      bitmap from1;
 542      bitmap from2;
 543      enum bitmap_bits operation;
 544 {
 545 #define HIGHEST_INDEX (unsigned int) ~0
 546
 547   bitmap_element *from1_ptr = from1->first;
 548   bitmap_element *from2_ptr = from2->first;
 549   unsigned int indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
 550   unsigned int indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
 551   bitmap_element *to_ptr = to->first;
 552   bitmap_element *from1_tmp;
 553   bitmap_element *from2_tmp;
 554   bitmap_element *to_tmp;
 555   unsigned int indx;
 556   int changed = 0;
 557
 558 #if BITMAP_ELEMENT_WORDS == 2
 559 #define DOIT(OP)                                        \
 560   do {                                                  \
 561     BITMAP_WORD t0, t1, f10, f11, f20, f21;             \
 562     f10 = from1_tmp->bits[0];                           \
 563     f20 = from2_tmp->bits[0];                           \
 564     t0 = f10 OP f20;                                    \
 565     changed |= (t0 != to_tmp->bits[0]);                 \
 566     f11 = from1_tmp->bits[1];                           \
 567     f21 = from2_tmp->bits[1];                           \
 568     t1 = f11 OP f21;                                    \
 569     changed |= (t1 != to_tmp->bits[1]);                 \
 570     to_tmp->bits[0] = t0;                               \
 571     to_tmp->bits[1] = t1;                               \
 572   } while (0)
 573 #else
 574 #define DOIT(OP)                                        \
 575   do {                                                  \
 576     BITMAP_WORD t, f1, f2;                              \
 577     int i;                                              \
 578     for (i = 0; i < BITMAP_ELEMENT_WORDS; ++i)          \
 579       {                                                 \
 580         f1 = from1_tmp->bits[i];                        \
 581         f2 = from2_tmp->bits[i];                        \
 582         t = f1 OP f2;                                   \
 583         changed |= (t != to_tmp->bits[i]);              \
 584         to_tmp->bits[i] = t;                            \
 585       }                                                 \
 586   } while (0)
 587 #endif
 588
 589   to->first = to->current = 0;
 590
 591   while (from1_ptr != 0 || from2_ptr != 0)
 592     {
 593       /* Figure out whether we need to substitute zero elements for
 594          missing links.  */
 595       if (indx1 == indx2)
 596         {
 597           indx = indx1;
 598           from1_tmp = from1_ptr;
 599           from2_tmp = from2_ptr;
 600           from1_ptr = from1_ptr->next;
 601           indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
 602           from2_ptr = from2_ptr->next;
 603           indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
 604         }
 605       else if (indx1 < indx2)
 606         {
 607           indx = indx1;
 608           from1_tmp = from1_ptr;
 609           from2_tmp = &bitmap_zero_bits;
 610           from1_ptr = from1_ptr->next;
 611           indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
 612         }
 613       else
 614         {
 615           indx = indx2;
 616           from1_tmp = &bitmap_zero_bits;
 617           from2_tmp = from2_ptr;
 618           from2_ptr = from2_ptr->next;
 619           indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
 620         }
 621
 622       /* Find the appropriate element from TO.  Begin by discarding
 623          elements that we've skipped.  */
 624       while (to_ptr && to_ptr->indx < indx)
 625         {
 626           changed = 1;
 627           to_tmp = to_ptr;
 628           to_ptr = to_ptr->next;
 629           bitmap_elem_to_freelist (to, to_tmp);
 630         }
 631       if (to_ptr && to_ptr->indx == indx)
 632         {
 633           to_tmp = to_ptr;
 634           to_ptr = to_ptr->next;
 635         }
 636       else
 637         to_tmp = bitmap_element_allocate (to);
 638
 639       /* Do the operation, and if any bits are set, link it into the
 640          linked list.  */
 641       switch (operation)
 642         {
 643         default:
 644           abort ();
 645
 646         case BITMAP_AND:
 647           DOIT (&);
 648           break;
 649
 650         case BITMAP_AND_COMPL:
 651           DOIT (&~);
 652           break;
 653
 654         case BITMAP_IOR:
 655           DOIT (|);
 656           break;
 657         case BITMAP_IOR_COMPL:
 658           DOIT (|~);
 659           break;
 660         case BITMAP_XOR:
 661           DOIT (^);
 662           break;
 663         }
 664
 665       if (! bitmap_element_zerop (to_tmp))
 666         {
 667           to_tmp->indx = indx;
 668           bitmap_element_link (to, to_tmp);
 669         }
 670       else
 671         {
 672           bitmap_elem_to_freelist (to, to_tmp);
 673         }
 674     }
 675
 676   /* If we have elements of TO left over, free the lot.  */
 677   if (to_ptr)
 678     {
 679       changed = 1;
 680       for (to_tmp = to_ptr; to_tmp->next ; to_tmp = to_tmp->next)
 681         continue;
 682       if (to->using_obstack)
 683         {
 684           to_tmp->next = bitmap_free;
 685           bitmap_free = to_ptr;
 686         }
 687       else
 688         {
 689           to_tmp->next = bitmap_ggc_free;
 690           bitmap_ggc_free = to_ptr;
 691         }
 692     }
 693
 694 #undef DOIT
 695
 696   return changed;
 697 }
 698
 699 /* Return true if two bitmaps are identical.  */
 700
 701 int
 702 bitmap_equal_p (a, b)
 703      bitmap a;
 704      bitmap b;
 705 {
 706   bitmap_head c;
 707   int ret;
 708
 709   memset (&c, 0, sizeof (c));
 710   ret = ! bitmap_operation (&c, a, b, BITMAP_XOR);
 711   bitmap_clear (&c);
 712
 713   return ret;
 714 }
 715 \f
 716 /* Or into bitmap TO bitmap FROM1 and'ed with the complement of
 717    bitmap FROM2.  */
 718
 719 void
 720 bitmap_ior_and_compl (to, from1, from2)
 721      bitmap to;
 722      bitmap from1;
 723      bitmap from2;
 724 {
 725   bitmap_head tmp;
 726
 727   tmp.first = tmp.current = 0;
 728   tmp.using_obstack = 0;
 729
 730   bitmap_operation (&tmp, from1, from2, BITMAP_AND_COMPL);
 731   bitmap_operation (to, to, &tmp, BITMAP_IOR);
 732   bitmap_clear (&tmp);
 733 }
 734
 735 int
 736 bitmap_union_of_diff (dst, a, b, c)
 737      bitmap dst;
 738      bitmap a;
 739      bitmap b;
 740      bitmap c;
 741 {
 742   bitmap_head tmp;
 743   int changed;
 744
 745   tmp.first = tmp.current = 0;
 746   tmp.using_obstack = 0;
 747
 748   bitmap_operation (&tmp, b, c, BITMAP_AND_COMPL);
 749   changed = bitmap_operation (dst, &tmp, a, BITMAP_IOR);
 750   bitmap_clear (&tmp);
 751
 752   return changed;
 753 }
 754 \f
 755 /* Initialize a bitmap header.  */
 756
 757 bitmap
 758 bitmap_initialize (head, using_obstack)
 759      bitmap head;
 760      int using_obstack;
 761 {
 762   if (head == NULL && ! using_obstack)
 763     head = ggc_alloc (sizeof (*head));
 764
 765   head->first = head->current = 0;
 766   head->using_obstack = using_obstack;
 767
 768   return head;
 769 }
 770 \f
 771 /* Debugging function to print out the contents of a bitmap.  */
 772
 773 void
 774 debug_bitmap_file (file, head)
 775      FILE *file;
 776      bitmap head;
 777 {
 778   bitmap_element *ptr;
 779
 780   fprintf (file, "\nfirst = ");
 781   fprintf (file, HOST_PTR_PRINTF, (PTR) head->first);
 782   fprintf (file, " current = ");
 783   fprintf (file, HOST_PTR_PRINTF, (PTR) head->current);
 784   fprintf (file, " indx = %u\n", head->indx);
 785
 786   for (ptr = head->first; ptr; ptr = ptr->next)
 787     {
 788       unsigned int i, j, col = 26;
 789
 790       fprintf (file, "\t");
 791       fprintf (file, HOST_PTR_PRINTF, (PTR) ptr);
 792       fprintf (file, " next = ");
 793       fprintf (file, HOST_PTR_PRINTF, (PTR) ptr->next);
 794       fprintf (file, " prev = ");
 795       fprintf (file, HOST_PTR_PRINTF, (PTR) ptr->prev);
 796       fprintf (file, " indx = %u\n\t\tbits = {", ptr->indx);
 797
 798       for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
 799         for (j = 0; j < BITMAP_WORD_BITS; j++)
 800           if ((ptr->bits[i] >> j) & 1)
 801             {
 802               if (col > 70)
 803                 {
 804                   fprintf (file, "\n\t\t\t");
 805                   col = 24;
 806                 }
 807
 808               fprintf (file, " %u", (ptr->indx * BITMAP_ELEMENT_ALL_BITS
 809                                      + i * BITMAP_WORD_BITS + j));
 810               col += 4;
 811             }
 812
 813       fprintf (file, " }\n");
 814     }
 815 }
 816
 817 /* Function to be called from the debugger to print the contents
 818    of a bitmap.  */
 819
 820 void
 821 debug_bitmap (head)
 822      bitmap head;
 823 {
 824   debug_bitmap_file (stdout, head);
 825 }
 826
 827 /* Function to print out the contents of a bitmap.  Unlike debug_bitmap_file,
 828    it does not print anything but the bits.  */
 829
 830 void
 831 bitmap_print (file, head, prefix, suffix)
 832      FILE *file;
 833      bitmap head;
 834      const char *prefix;
 835      const char *suffix;
 836 {
 837   const char *comma = "";
 838   int i;
 839
 840   fputs (prefix, file);
 841   EXECUTE_IF_SET_IN_BITMAP (head, 0, i,
 842                             {
 843                               fprintf (file, "%s%d", comma, i);
 844                               comma = ", ";
 845                             });
 846   fputs (suffix, file);
 847 }
 848
 849 #include "gt-bitmap.h"