diff options
author | Jeff Garzik <jeff@garzik.org> | 2006-03-29 17:24:55 -0500 |
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committer | Jeff Garzik <jeff@garzik.org> | 2006-03-29 17:24:55 -0500 |
commit | 74d89c16735d83349ea74232031819e989a49156 (patch) | |
tree | 1d8ded9c76b6ebe97c3841bbb986aacd63a801e5 /include/asm-generic/bitops/fls.h | |
parent | 52a3220599647ba429fcbca2388ec35b850fa72f (diff) | |
parent | 05c8e0ac5c37e9739a852b526afeecae97607cbb (diff) |
Merge branch 'upstream'
Diffstat (limited to 'include/asm-generic/bitops/fls.h')
-rw-r--r-- | include/asm-generic/bitops/fls.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h new file mode 100644 index 000000000000..850859bc5069 --- /dev/null +++ b/include/asm-generic/bitops/fls.h | |||
@@ -0,0 +1,41 @@ | |||
1 | #ifndef _ASM_GENERIC_BITOPS_FLS_H_ | ||
2 | #define _ASM_GENERIC_BITOPS_FLS_H_ | ||
3 | |||
4 | /** | ||
5 | * fls - find last (most-significant) bit set | ||
6 | * @x: the word to search | ||
7 | * | ||
8 | * This is defined the same way as ffs. | ||
9 | * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. | ||
10 | */ | ||
11 | |||
12 | static inline int fls(int x) | ||
13 | { | ||
14 | int r = 32; | ||
15 | |||
16 | if (!x) | ||
17 | return 0; | ||
18 | if (!(x & 0xffff0000u)) { | ||
19 | x <<= 16; | ||
20 | r -= 16; | ||
21 | } | ||
22 | if (!(x & 0xff000000u)) { | ||
23 | x <<= 8; | ||
24 | r -= 8; | ||
25 | } | ||
26 | if (!(x & 0xf0000000u)) { | ||
27 | x <<= 4; | ||
28 | r -= 4; | ||
29 | } | ||
30 | if (!(x & 0xc0000000u)) { | ||
31 | x <<= 2; | ||
32 | r -= 2; | ||
33 | } | ||
34 | if (!(x & 0x80000000u)) { | ||
35 | x <<= 1; | ||
36 | r -= 1; | ||
37 | } | ||
38 | return r; | ||
39 | } | ||
40 | |||
41 | #endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ | ||