1 | #ifndef _LINUX_BITOPS_H |
2 | #define _LINUX_BITOPS_H |
3 | |
4 | |
5 | |
6 | |
7 | |
8 | |
9 | |
10 | |
11 | extern __inline__ int generic_ffs(int x) |
12 | { |
13 | int r = 1; |
14 | |
15 | if (!x) |
16 | return 0; |
17 | if (!(x & 0xffff)) { |
18 | x >>= 16; |
19 | r += 16; |
20 | } |
21 | if (!(x & 0xff)) { |
22 | x >>= 8; |
23 | r += 8; |
24 | } |
25 | if (!(x & 0xf)) { |
26 | x >>= 4; |
27 | r += 4; |
28 | } |
29 | if (!(x & 3)) { |
30 | x >>= 2; |
31 | r += 2; |
32 | } |
33 | if (!(x & 1)) { |
34 | x >>= 1; |
| Value stored to 'x' is never read |
35 | r += 1; |
36 | } |
37 | return r; |
38 | } |
39 | |
40 | |
41 | |
42 | |
43 | |
44 | |
45 | extern __inline__ unsigned int generic_hweight32(unsigned int w) |
46 | { |
47 | unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555); |
48 | res = (res & 0x33333333) + ((res >> 2) & 0x33333333); |
49 | res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F); |
50 | res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF); |
51 | return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF); |
52 | } |
53 | |
54 | extern __inline__ unsigned int generic_hweight16(unsigned int w) |
55 | { |
56 | unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555); |
57 | res = (res & 0x3333) + ((res >> 2) & 0x3333); |
58 | res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F); |
59 | return (res & 0x00FF) + ((res >> 8) & 0x00FF); |
60 | } |
61 | |
62 | extern __inline__ unsigned int generic_hweight8(unsigned int w) |
63 | { |
64 | unsigned int res = (w & 0x55) + ((w >> 1) & 0x55); |
65 | res = (res & 0x33) + ((res >> 2) & 0x33); |
66 | return (res & 0x0F) + ((res >> 4) & 0x0F); |
67 | } |
68 | |
69 | #include <asm/bitops.h> |
70 | |
71 | |
72 | #endif |