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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#ifndef __XFS_BIT_H__
7#define __XFS_BIT_H__
8
9/*
10 * XFS bit manipulation routines.
11 */
12
13/*
14 * masks with n high/low bits set, 64-bit values
15 */
16static inline uint64_t xfs_mask64hi(int n)
17{
18 return (uint64_t)-1 << (64 - (n));
19}
20static inline uint32_t xfs_mask32lo(int n)
21{
22 return ((uint32_t)1 << (n)) - 1;
23}
24static inline uint64_t xfs_mask64lo(int n)
25{
26 return ((uint64_t)1 << (n)) - 1;
27}
28
29/* Get high bit set out of 32-bit argument, -1 if none set */
30static inline int xfs_highbit32(uint32_t v)
31{
32 return fls(v) - 1;
33}
34
35/* Get high bit set out of 64-bit argument, -1 if none set */
36static inline int xfs_highbit64(uint64_t v)
37{
38 return fls64(v) - 1;
39}
40
41/* Get low bit set out of 32-bit argument, -1 if none set */
42static inline int xfs_lowbit32(uint32_t v)
43{
44 return ffs(v) - 1;
45}
46
47/* Get low bit set out of 64-bit argument, -1 if none set */
48static inline int xfs_lowbit64(uint64_t v)
49{
50 uint32_t w = (uint32_t)v;
51 int n = 0;
52
53 if (w) { /* lower bits */
54 n = ffs(w);
55 } else { /* upper bits */
56 w = (uint32_t)(v >> 32);
57 if (w) {
58 n = ffs(w);
59 if (n)
60 n += 32;
61 }
62 }
63 return n - 1;
64}
65
66/* Return whether bitmap is empty (1 == empty) */
67extern int xfs_bitmap_empty(uint *map, uint size);
68
69/* Count continuous one bits in map starting with start_bit */
70extern int xfs_contig_bits(uint *map, uint size, uint start_bit);
71
72/* Find next set bit in map */
73extern int xfs_next_bit(uint *map, uint size, uint start_bit);
74
75#endif /* __XFS_BIT_H__ */
1/*
2 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#ifndef __XFS_BIT_H__
19#define __XFS_BIT_H__
20
21/*
22 * XFS bit manipulation routines.
23 */
24
25/*
26 * masks with n high/low bits set, 64-bit values
27 */
28static inline __uint64_t xfs_mask64hi(int n)
29{
30 return (__uint64_t)-1 << (64 - (n));
31}
32static inline __uint32_t xfs_mask32lo(int n)
33{
34 return ((__uint32_t)1 << (n)) - 1;
35}
36static inline __uint64_t xfs_mask64lo(int n)
37{
38 return ((__uint64_t)1 << (n)) - 1;
39}
40
41/* Get high bit set out of 32-bit argument, -1 if none set */
42static inline int xfs_highbit32(__uint32_t v)
43{
44 return fls(v) - 1;
45}
46
47/* Get high bit set out of 64-bit argument, -1 if none set */
48static inline int xfs_highbit64(__uint64_t v)
49{
50 return fls64(v) - 1;
51}
52
53/* Get low bit set out of 32-bit argument, -1 if none set */
54static inline int xfs_lowbit32(__uint32_t v)
55{
56 return ffs(v) - 1;
57}
58
59/* Get low bit set out of 64-bit argument, -1 if none set */
60static inline int xfs_lowbit64(__uint64_t v)
61{
62 __uint32_t w = (__uint32_t)v;
63 int n = 0;
64
65 if (w) { /* lower bits */
66 n = ffs(w);
67 } else { /* upper bits */
68 w = (__uint32_t)(v >> 32);
69 if (w) {
70 n = ffs(w);
71 if (n)
72 n += 32;
73 }
74 }
75 return n - 1;
76}
77
78/* Return whether bitmap is empty (1 == empty) */
79extern int xfs_bitmap_empty(uint *map, uint size);
80
81/* Count continuous one bits in map starting with start_bit */
82extern int xfs_contig_bits(uint *map, uint size, uint start_bit);
83
84/* Find next set bit in map */
85extern int xfs_next_bit(uint *map, uint size, uint start_bit);
86
87#endif /* __XFS_BIT_H__ */