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2bd0ea18 | 1 | /* |
f302e9e4 NS |
2 | * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
5000d01d | 4 | * |
f302e9e4 NS |
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 | |
2bd0ea18 | 7 | * published by the Free Software Foundation. |
5000d01d | 8 | * |
f302e9e4 NS |
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. | |
5000d01d | 13 | * |
f302e9e4 NS |
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 | |
2bd0ea18 NS |
17 | */ |
18 | #ifndef __XFS_BIT_H__ | |
dfc130f3 | 19 | #define __XFS_BIT_H__ |
2bd0ea18 NS |
20 | |
21 | /* | |
22 | * XFS bit manipulation routines. | |
23 | */ | |
24 | ||
25 | /* | |
56b2de80 | 26 | * masks with n high/low bits set, 64-bit values |
2bd0ea18 | 27 | */ |
4a492e72 | 28 | static inline uint64_t xfs_mask64hi(int n) |
f302e9e4 | 29 | { |
4a492e72 | 30 | return (uint64_t)-1 << (64 - (n)); |
f302e9e4 | 31 | } |
4a492e72 | 32 | static inline uint32_t xfs_mask32lo(int n) |
f302e9e4 | 33 | { |
4a492e72 | 34 | return ((uint32_t)1 << (n)) - 1; |
f302e9e4 | 35 | } |
4a492e72 | 36 | static inline uint64_t xfs_mask64lo(int n) |
f302e9e4 | 37 | { |
4a492e72 | 38 | return ((uint64_t)1 << (n)) - 1; |
f302e9e4 | 39 | } |
2bd0ea18 | 40 | |
d4ae0811 | 41 | /* Get high bit set out of 32-bit argument, -1 if none set */ |
4a492e72 | 42 | static inline int xfs_highbit32(uint32_t v) |
5e656dbb BN |
43 | { |
44 | return fls(v) - 1; | |
45 | } | |
46 | ||
47 | /* Get high bit set out of 64-bit argument, -1 if none set */ | |
4a492e72 | 48 | static inline int xfs_highbit64(uint64_t v) |
5e656dbb BN |
49 | { |
50 | return fls64(v) - 1; | |
51 | } | |
52 | ||
53 | /* Get low bit set out of 32-bit argument, -1 if none set */ | |
4a492e72 | 54 | static inline int xfs_lowbit32(uint32_t v) |
5e656dbb BN |
55 | { |
56 | return ffs(v) - 1; | |
57 | } | |
2bd0ea18 | 58 | |
d4ae0811 | 59 | /* Get low bit set out of 64-bit argument, -1 if none set */ |
4a492e72 | 60 | static inline int xfs_lowbit64(uint64_t v) |
5e656dbb | 61 | { |
4a492e72 | 62 | uint32_t w = (uint32_t)v; |
5e656dbb | 63 | int n = 0; |
2bd0ea18 | 64 | |
5e656dbb BN |
65 | if (w) { /* lower bits */ |
66 | n = ffs(w); | |
67 | } else { /* upper bits */ | |
4a492e72 | 68 | w = (uint32_t)(v >> 32); |
ff105f75 DC |
69 | if (w) { |
70 | n = ffs(w); | |
71 | if (n) | |
72 | n += 32; | |
73 | } | |
5e656dbb BN |
74 | } |
75 | return n - 1; | |
76 | } | |
2bd0ea18 | 77 | |
5e656dbb BN |
78 | /* Return whether bitmap is empty (1 == empty) */ |
79 | extern int xfs_bitmap_empty(uint *map, uint size); | |
d4ae0811 NS |
80 | |
81 | /* Count continuous one bits in map starting with start_bit */ | |
82 | extern int xfs_contig_bits(uint *map, uint size, uint start_bit); | |
83 | ||
84 | /* Find next set bit in map */ | |
85 | extern int xfs_next_bit(uint *map, uint size, uint start_bit); | |
86 | ||
2bd0ea18 | 87 | #endif /* __XFS_BIT_H__ */ |