xfs_bit.h
2.15 KB
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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
/*
* Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* 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.
*
* This program is distributed in the hope that it would 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, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_BIT_H__
#define __XFS_BIT_H__
/*
* XFS bit manipulation routines.
*/
/*
* masks with n high/low bits set, 64-bit values
*/
static inline __uint64_t xfs_mask64hi(int n)
{
return (__uint64_t)-1 << (64 - (n));
}
static inline __uint32_t xfs_mask32lo(int n)
{
return ((__uint32_t)1 << (n)) - 1;
}
static inline __uint64_t xfs_mask64lo(int n)
{
return ((__uint64_t)1 << (n)) - 1;
}
/* Get high bit set out of 32-bit argument, -1 if none set */
static inline int xfs_highbit32(__uint32_t v)
{
return fls(v) - 1;
}
/* Get high bit set out of 64-bit argument, -1 if none set */
static inline int xfs_highbit64(__uint64_t v)
{
return fls64(v) - 1;
}
/* Get low bit set out of 32-bit argument, -1 if none set */
static inline int xfs_lowbit32(__uint32_t v)
{
return ffs(v) - 1;
}
/* Get low bit set out of 64-bit argument, -1 if none set */
static inline int xfs_lowbit64(__uint64_t v)
{
__uint32_t w = (__uint32_t)v;
int n = 0;
if (w) { /* lower bits */
n = ffs(w);
} else { /* upper bits */
w = (__uint32_t)(v >> 32);
if (w) {
n = ffs(w);
if (n)
n += 32;
}
}
return n - 1;
}
/* Return whether bitmap is empty (1 == empty) */
extern int xfs_bitmap_empty(uint *map, uint size);
/* Count continuous one bits in map starting with start_bit */
extern int xfs_contig_bits(uint *map, uint size, uint start_bit);
/* Find next set bit in map */
extern int xfs_next_bit(uint *map, uint size, uint start_bit);
#endif /* __XFS_BIT_H__ */