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/*
* Copyright (c) 2013-2015 Richard Braun.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Upstream site with license notes :
* http://git.sceen.net/rbraun/librbraun.git/
*/
#include <limits.h>
#include <string.h>
#include "bitmap.h"
#include "bitmap_i.h"
int
bitmap_cmp(const unsigned long *a, const unsigned long *b, int nr_bits)
{
unsigned long last_a, last_b, mask;
int n, rv;
n = BITMAP_LONGS(nr_bits) - 1;
if (n != 0) {
rv = memcmp(a, b, n * sizeof(unsigned long));
if (rv != 0) {
return rv;
}
nr_bits -= n * LONG_BIT;
}
last_a = a[n];
last_b = b[n];
if (nr_bits != LONG_BIT) {
mask = (1UL << nr_bits) - 1;
last_a &= mask;
last_b &= mask;
}
if (last_a == last_b) {
return 0;
} else if (last_a < last_b) {
return -1;
} else {
return 1;
}
}
static inline unsigned long
bitmap_find_next_compute_complement(unsigned long word, int nr_bits)
{
if (nr_bits < LONG_BIT) {
word |= (((unsigned long)-1) << nr_bits);
}
return ~word;
}
int
bitmap_find_next_bit(const unsigned long *bm, int nr_bits, int bit,
int complement)
{
const unsigned long *start, *end;
unsigned long word;
start = bm;
end = bm + BITMAP_LONGS(nr_bits);
if (bit >= LONG_BIT) {
bitmap_lookup(&bm, &bit);
nr_bits -= ((bm - start) * LONG_BIT);
}
word = *bm;
if (complement) {
word = bitmap_find_next_compute_complement(word, nr_bits);
}
if (bit < LONG_BIT) {
word &= ~(bitmap_mask(bit) - 1);
}
for (;;) {
bit = __builtin_ffsl(word);
if (bit != 0) {
return ((bm - start) * LONG_BIT) + bit - 1;
}
bm++;
if (bm >= end) {
return -1;
}
nr_bits -= LONG_BIT;
word = *bm;
if (complement) {
word = bitmap_find_next_compute_complement(word, nr_bits);
}
}
}
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