blob: 0852b6a1374fcf8ac30d40b83c0effacef809a5b (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
/*
* Copyright (C) 2011-2018 Free Software Foundation, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Eric Blake. */
#include <config.h>
#include <string.h>
#include "signature.h"
SIGNATURE_CHECK (ffsl, int, (long int));
#include <limits.h>
#include "macros.h"
#define NBITS (sizeof (long int) * CHAR_BIT)
static int
naive (long int i)
{
unsigned long int j;
for (j = 0; j < NBITS; j++)
if (i & (1UL << j))
return j + 1;
return 0;
}
int
main (int argc, char *argv[])
{
long int x;
int i;
for (x = -128; x <= 128; x++)
ASSERT (ffsl (x) == naive (x));
for (i = 0; i < NBITS; i++)
{
ASSERT (ffsl (1UL << i) == naive (1UL << i));
ASSERT (ffsl (1UL << i) == i + 1);
ASSERT (ffsl (-1UL << i) == i + 1);
}
for (i = 0; i < NBITS - 1; i++)
{
ASSERT (ffsl (3UL << i) == i + 1);
ASSERT (ffsl (-3UL << i) == i + 1);
}
for (i = 0; i < NBITS - 2; i++)
{
ASSERT (ffsl (5UL << i) == i + 1);
ASSERT (ffsl (-5UL << i) == i + 1);
ASSERT (ffsl (7UL << i) == i + 1);
ASSERT (ffsl (-7UL << i) == i + 1);
}
return 0;
}
|
