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ef01750240
* lib/ebitset.c, lib/ebitset.h, lib/lbitset.c, lib/lbitset.h, * lib/sbitset.c, lib/sbitset.h, lib/bbitset.h: Update from the latest sources from Michael.
686 lines
14 KiB
C
686 lines
14 KiB
C
/* Simple bitsets.
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Copyright (C) 2002 Free Software Foundation, Inc.
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Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "sbitset.h"
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#include <stdlib.h>
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#include <string.h>
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/* This file implements fixed size bitsets stored as an array
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of words. Any unused bits in the last word must be zero. */
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typedef struct sbitset_struct
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{
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unsigned int n_bits; /* Number of bits. */
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bitset_word words[1]; /* The array of bits. */
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}
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*sbitset;
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struct bitset_struct
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{
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struct bbitset_struct b;
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struct sbitset_struct s;
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};
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static void sbitset_unused_clear PARAMS ((bitset));
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static int sbitset_small_list PARAMS ((bitset, bitset_bindex *, bitset_bindex,
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bitset_bindex *));
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static void sbitset_set PARAMS ((bitset, bitset_bindex));
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static void sbitset_reset PARAMS ((bitset, bitset_bindex));
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static int sbitset_test PARAMS ((bitset, bitset_bindex));
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static int sbitset_size PARAMS ((bitset));
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static int sbitset_op1 PARAMS ((bitset, enum bitset_ops));
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static int sbitset_op2 PARAMS ((bitset, bitset, enum bitset_ops));
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static int sbitset_op3 PARAMS ((bitset, bitset, bitset, enum bitset_ops));
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static int sbitset_op4 PARAMS ((bitset, bitset, bitset, bitset,
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enum bitset_ops));
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static int sbitset_list PARAMS ((bitset, bitset_bindex *, bitset_bindex,
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bitset_bindex *));
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static int sbitset_reverse_list
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PARAMS ((bitset, bitset_bindex *, bitset_bindex, bitset_bindex *));
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#define SBITSET_N_WORDS(N) (((N) + BITSET_WORD_BITS - 1) / BITSET_WORD_BITS)
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#define SBITSET_WORDS(X) ((X)->s.words)
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#define SBITSET_N_BITS(X) ((X)->s.n_bits)
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/* Return size in bits of bitset SRC. */
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static int
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sbitset_size (src)
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bitset src;
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{
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return SBITSET_N_BITS (src);
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}
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/* Find list of up to NUM bits set in BSET starting from and including
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*NEXT and store in array LIST. Return with actual number of bits
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found and with *NEXT indicating where search stopped. */
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static int
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sbitset_small_list (src, list, num, next)
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bitset src;
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bitset_bindex *list;
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bitset_bindex num;
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bitset_bindex *next;
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{
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bitset_bindex bitno;
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bitset_bindex count;
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bitset_windex size;
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bitset_word word;
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word = SBITSET_WORDS (src)[0];
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/* Short circuit common case. */
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if (!word)
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return 0;
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size = SBITSET_N_BITS (src);
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bitno = *next;
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if (bitno >= size)
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return 0;
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word >>= bitno;
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/* If num is 1, we could speed things up with a binary search
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of the word of interest. */
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if (num >= BITSET_WORD_BITS)
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{
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for (count = 0; word; bitno++)
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{
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if (word & 1)
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list[count++] = bitno;
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word >>= 1;
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}
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}
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else
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{
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for (count = 0; word; bitno++)
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{
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if (word & 1)
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{
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list[count++] = bitno;
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if (count >= num)
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{
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bitno++;
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break;
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}
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}
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word >>= 1;
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}
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}
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*next = bitno;
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return count;
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}
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/* Set bit BITNO in bitset DST. */
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static void
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sbitset_set (dst, bitno)
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bitset dst ATTRIBUTE_UNUSED;
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bitset_bindex bitno ATTRIBUTE_UNUSED;
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{
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/* This should never occur for sbitsets. */
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abort ();
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}
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/* Reset bit BITNO in bitset DST. */
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static void
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sbitset_reset (dst, bitno)
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bitset dst ATTRIBUTE_UNUSED;
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bitset_bindex bitno ATTRIBUTE_UNUSED;
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{
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/* This should never occur for sbitsets. */
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abort ();
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}
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/* Test bit BITNO in bitset SRC. */
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static int
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sbitset_test (src, bitno)
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bitset src ATTRIBUTE_UNUSED;
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bitset_bindex bitno ATTRIBUTE_UNUSED;
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{
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/* This should never occur for sbitsets. */
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abort ();
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return 0;
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}
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/* Find list of up to NUM bits set in BSET in reverse order, starting
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from and including NEXT and store in array LIST. Return with
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actual number of bits found and with *NEXT indicating where search
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stopped. */
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static int
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sbitset_reverse_list (src, list, num, next)
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bitset src;
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bitset_bindex *list;
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bitset_bindex num;
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bitset_bindex *next;
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{
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bitset_bindex bitno;
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bitset_bindex rbitno;
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bitset_bindex count;
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bitset_windex index;
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unsigned int bitcnt;
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bitset_bindex bitoff;
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bitset_word word;
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bitset_word *srcp = SBITSET_WORDS (src);
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bitset_bindex n_bits = SBITSET_N_BITS (src);
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rbitno = *next;
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/* If num is 1, we could speed things up with a binary search
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of the word of interest. */
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if (rbitno >= n_bits)
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return 0;
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count = 0;
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bitno = n_bits - (rbitno + 1);
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index = bitno / BITSET_WORD_BITS;
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bitcnt = bitno % BITSET_WORD_BITS;
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bitoff = index * BITSET_WORD_BITS;
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for (; index != ~0U; index--, bitoff -= BITSET_WORD_BITS,
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bitcnt = BITSET_WORD_BITS - 1)
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{
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word = srcp[index] << (BITSET_WORD_BITS - 1 - bitcnt);
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for (; word; bitcnt--)
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{
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if (word & BITSET_MSB)
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{
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list[count++] = bitoff + bitcnt;
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if (count >= num)
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{
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*next = n_bits - (bitoff + bitcnt);
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return count;
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}
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}
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word <<= 1;
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}
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}
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*next = n_bits - (bitoff + 1);
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return count;
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}
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/* Find list of up to NUM bits set in BSET starting from and including
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*NEXT and store in array LIST. Return with actual number of bits
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found and with *NEXT indicating where search stopped. */
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static int
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sbitset_list (src, list, num, next)
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bitset src;
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bitset_bindex *list;
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bitset_bindex num;
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bitset_bindex *next;
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{
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bitset_bindex bitno;
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bitset_bindex count;
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bitset_windex index;
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bitset_bindex bitoff;
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bitset_windex size = src->b.csize;
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bitset_word *srcp = SBITSET_WORDS (src);
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bitset_word word;
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bitno = *next;
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count = 0;
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if (!bitno)
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{
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/* Many bitsets are zero, so make this common case fast. */
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for (index = 0; index < size && !srcp[index]; index++)
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continue;
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if (index >= size)
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return 0;
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/* If num is 1, we could speed things up with a binary search
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of the current word. */
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bitoff = index * BITSET_WORD_BITS;
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}
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else
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{
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if (bitno >= SBITSET_N_BITS (src))
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return 0;
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index = bitno / BITSET_WORD_BITS;
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bitno = bitno % BITSET_WORD_BITS;
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if (bitno)
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{
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/* Handle the case where we start within a word.
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Most often, this is executed with large bitsets
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with many set bits where we filled the array
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on the previous call to this function. */
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bitoff = index * BITSET_WORD_BITS;
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word = srcp[index] >> bitno;
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for (bitno = bitoff + bitno; word; bitno++)
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{
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if (word & 1)
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{
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list[count++] = bitno;
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if (count >= num)
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{
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*next = bitno + 1;
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return count;
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}
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}
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word >>= 1;
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}
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index++;
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}
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bitoff = index * BITSET_WORD_BITS;
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}
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for (; index < size; index++, bitoff += BITSET_WORD_BITS)
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{
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if (!(word = srcp[index]))
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continue;
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if ((count + BITSET_WORD_BITS) < num)
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{
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for (bitno = bitoff; word; bitno++)
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{
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if (word & 1)
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list[count++] = bitno;
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word >>= 1;
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}
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}
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else
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{
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for (bitno = bitoff; word; bitno++)
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{
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if (word & 1)
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{
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list[count++] = bitno;
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if (count >= num)
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{
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*next = bitno + 1;
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return count;
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}
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}
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word >>= 1;
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}
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}
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}
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*next = bitoff;
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return count;
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}
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/* Ensure that any unused bits within the last word are clear. */
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static inline void
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sbitset_unused_clear (dst)
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bitset dst;
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{
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unsigned int last_bit;
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last_bit = SBITSET_N_BITS (dst) % BITSET_WORD_BITS;
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if (last_bit)
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SBITSET_WORDS (dst)[dst->b.csize - 1] &=
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(bitset_word) ((1 << last_bit) - 1);
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}
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static int
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sbitset_op1 (dst, op)
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bitset dst;
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enum bitset_ops op;
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{
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unsigned int i;
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bitset_word *dstp = SBITSET_WORDS (dst);
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unsigned int bytes;
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bytes = sizeof (bitset_word) * dst->b.csize;
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switch (op)
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{
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case BITSET_OP_ZERO:
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memset (dstp, 0, bytes);
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break;
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case BITSET_OP_ONES:
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memset (dstp, ~0, bytes);
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sbitset_unused_clear (dst);
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break;
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case BITSET_OP_EMPTY_P:
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for (i = 0; i < dst->b.csize; i++)
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if (dstp[i])
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return 0;
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break;
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default:
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abort ();
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}
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return 1;
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}
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static int
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sbitset_op2 (dst, src, op)
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bitset dst;
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bitset src;
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enum bitset_ops op;
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{
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unsigned int i;
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bitset_word *srcp = SBITSET_WORDS (src);
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bitset_word *dstp = SBITSET_WORDS (dst);
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bitset_windex size = dst->b.csize;
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#ifdef ENABLE_CHECKING
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/* Check for compatiblity. */
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if (SBITSET_N_BITS (src) != SBITSET_N_BITS (dst))
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abort ();
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#endif
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switch (op)
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{
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case BITSET_OP_COPY:
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if (srcp == dstp)
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break;
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memcpy (dstp, srcp, sizeof (bitset_word) * size);
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break;
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case BITSET_OP_NOT:
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for (i = 0; i < size; i++)
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*dstp++ = ~(*srcp++);
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sbitset_unused_clear (dst);
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break;
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case BITSET_OP_EQUAL_P:
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for (i = 0; i < size; i++)
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if (*srcp++ != *dstp++)
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return 0;
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break;
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case BITSET_OP_SUBSET_P:
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for (i = 0; i < size; i++, dstp++, srcp++)
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if (*dstp != (*srcp | *dstp))
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return 0;
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break;
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case BITSET_OP_DISJOINT_P:
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for (i = 0; i < size; i++)
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if (*srcp++ & *dstp++)
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return 0;
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break;
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default:
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abort ();
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}
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return 1;
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}
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static int
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sbitset_op3 (dst, src1, src2, op)
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bitset dst;
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bitset src1;
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bitset src2;
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enum bitset_ops op;
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{
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unsigned int i;
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int changed = 0;
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bitset_word *src1p = SBITSET_WORDS (src1);
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bitset_word *src2p = SBITSET_WORDS (src2);
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bitset_word *dstp = SBITSET_WORDS (dst);
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bitset_windex size = dst->b.csize;
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#ifdef ENABLE_CHECKING
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/* Check for compatiblity. */
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if (SBITSET_N_BITS (src1) != SBITSET_N_BITS (dst)
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SBITSET_N_BITS (src2) != SBITSET_N_BITS (dst))
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abort ();
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#endif
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switch (op)
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{
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case BITSET_OP_OR:
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for (i = 0; i < size; i++, dstp++)
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{
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bitset_word tmp = *src1p++ | *src2p++;
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if (*dstp != tmp)
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{
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changed = 1;
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*dstp = tmp;
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}
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}
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break;
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case BITSET_OP_AND:
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for (i = 0; i < size; i++, dstp++)
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{
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bitset_word tmp = *src1p++ & *src2p++;
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if (*dstp != tmp)
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{
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changed = 1;
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*dstp = tmp;
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}
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}
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break;
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case BITSET_OP_XOR:
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for (i = 0; i < size; i++, dstp++)
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{
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bitset_word tmp = *src1p++ ^ *src2p++;
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if (*dstp != tmp)
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{
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changed = 1;
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*dstp = tmp;
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}
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}
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break;
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case BITSET_OP_ANDN:
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for (i = 0; i < size; i++, dstp++)
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{
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bitset_word tmp = *src1p++ & ~(*src2p++);
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if (*dstp != tmp)
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{
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changed = 1;
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*dstp = tmp;
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}
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}
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break;
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case BITSET_OP_ORN:
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for (i = 0; i < size; i++, dstp++)
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{
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bitset_word tmp = *src1p++ | ~(*src2p++);
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if (*dstp != tmp)
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{
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changed = 1;
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*dstp = tmp;
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}
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}
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sbitset_unused_clear (dst);
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break;
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default:
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abort ();
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}
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return changed;
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}
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static int
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sbitset_op4 (dst, src1, src2, src3, op)
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bitset dst;
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bitset src1;
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bitset src2;
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bitset src3;
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enum bitset_ops op;
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{
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unsigned int i;
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int changed = 0;
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bitset_word *src1p = SBITSET_WORDS (src1);
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bitset_word *src2p = SBITSET_WORDS (src2);
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bitset_word *src3p = SBITSET_WORDS (src3);
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bitset_word *dstp = SBITSET_WORDS (dst);
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bitset_windex size = dst->b.csize;
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#ifdef ENABLE_CHECKING
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/* Check for compatiblity. */
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if (SBITSET_N_BITS (src1) != SBITSET_N_BITS (dst)
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|| SBITSET_N_BITS (src2) != SBITSET_N_BITS (dst)
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|| SBITSET_N_BITS (src3) != SBITSET_N_BITS (dst))
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abort ();
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#endif
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switch (op)
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{
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case BITSET_OP_OR_AND:
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for (i = 0; i < size; i++, dstp++)
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{
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bitset_word tmp = (*src1p++ | *src2p++) & *src3p++;
|
|
|
|
if (*dstp != tmp)
|
|
{
|
|
changed = 1;
|
|
*dstp = tmp;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case BITSET_OP_AND_OR:
|
|
for (i = 0; i < size; i++, dstp++)
|
|
{
|
|
bitset_word tmp = (*src1p++ & *src2p++) | *src3p++;
|
|
|
|
if (*dstp != tmp)
|
|
{
|
|
changed = 1;
|
|
*dstp = tmp;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case BITSET_OP_ANDN_OR:
|
|
for (i = 0; i < size; i++, dstp++)
|
|
{
|
|
bitset_word tmp = (*src1p++ & ~(*src2p++)) | *src3p++;
|
|
|
|
if (*dstp != tmp)
|
|
{
|
|
changed = 1;
|
|
*dstp = tmp;
|
|
}
|
|
}
|
|
break;
|
|
|
|
default:
|
|
abort ();
|
|
}
|
|
|
|
return changed;
|
|
}
|
|
|
|
|
|
/* Vector of operations for single word bitsets. */
|
|
struct bitset_ops_struct sbitset_small_ops = {
|
|
sbitset_set,
|
|
sbitset_reset,
|
|
sbitset_test,
|
|
sbitset_size,
|
|
sbitset_op1,
|
|
sbitset_op2,
|
|
sbitset_op3,
|
|
sbitset_op4,
|
|
sbitset_small_list,
|
|
sbitset_reverse_list,
|
|
NULL,
|
|
BITSET_ARRAY
|
|
};
|
|
|
|
|
|
/* Vector of operations for multiple word bitsets. */
|
|
struct bitset_ops_struct sbitset_ops = {
|
|
sbitset_set,
|
|
sbitset_reset,
|
|
sbitset_test,
|
|
sbitset_size,
|
|
sbitset_op1,
|
|
sbitset_op2,
|
|
sbitset_op3,
|
|
sbitset_op4,
|
|
sbitset_list,
|
|
sbitset_reverse_list,
|
|
NULL,
|
|
BITSET_ARRAY
|
|
};
|
|
|
|
|
|
int
|
|
sbitset_bytes (n_bits)
|
|
bitset_bindex n_bits;
|
|
{
|
|
unsigned int bytes, size;
|
|
|
|
size = SBITSET_N_WORDS (n_bits);
|
|
bytes = size * sizeof (bitset_word);
|
|
return sizeof (struct bitset_struct) + bytes - sizeof (bitset_word);
|
|
}
|
|
|
|
|
|
bitset
|
|
sbitset_init (bset, n_bits)
|
|
bitset bset;
|
|
bitset_bindex n_bits;
|
|
{
|
|
bitset_windex size;
|
|
|
|
size = SBITSET_N_WORDS (n_bits);
|
|
SBITSET_N_BITS (bset) = n_bits;
|
|
|
|
/* Use optimized routines if bitset fits within a single word.
|
|
There is probably little merit if using caching since
|
|
the small bitset will always fit in the cache. */
|
|
if (size == 1)
|
|
bset->b.ops = &sbitset_small_ops;
|
|
else
|
|
bset->b.ops = &sbitset_ops;
|
|
|
|
bset->b.cindex = 0;
|
|
bset->b.csize = size;
|
|
bset->b.cdata = SBITSET_WORDS (bset);
|
|
return bset;
|
|
}
|