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| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2012-02-19 06:14:24 +0000 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2012-02-19 06:14:24 +0000 |
| commit | 6fafeb146e9efd59140ea58cebd7dd38ae9a6379 (patch) | |
| tree | 7db89ba6a28932514b105d620bba4884ec332ec3 /libdde_linux26/contrib/include/asm-generic/bitops/fls.h | |
| parent | 38c2c2458e3f4ecb329ff35621806252aac209b9 (diff) | |
| parent | 8df772b3c665e663f6f9d2a70f9c691590bd3f91 (diff) | |
Merge branch 'dde' into upstream-merged
Diffstat (limited to 'libdde_linux26/contrib/include/asm-generic/bitops/fls.h')
| -rw-r--r-- | libdde_linux26/contrib/include/asm-generic/bitops/fls.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/libdde_linux26/contrib/include/asm-generic/bitops/fls.h b/libdde_linux26/contrib/include/asm-generic/bitops/fls.h new file mode 100644 index 00000000..0576d1f4 --- /dev/null +++ b/libdde_linux26/contrib/include/asm-generic/bitops/fls.h @@ -0,0 +1,41 @@ +#ifndef _ASM_GENERIC_BITOPS_FLS_H_ +#define _ASM_GENERIC_BITOPS_FLS_H_ + +/** + * fls - find last (most-significant) bit set + * @x: the word to search + * + * This is defined the same way as ffs. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ + +static __always_inline int fls(int x) +{ + int r = 32; + + if (!x) + return 0; + if (!(x & 0xffff0000u)) { + x <<= 16; + r -= 16; + } + if (!(x & 0xff000000u)) { + x <<= 8; + r -= 8; + } + if (!(x & 0xf0000000u)) { + x <<= 4; + r -= 4; + } + if (!(x & 0xc0000000u)) { + x <<= 2; + r -= 2; + } + if (!(x & 0x80000000u)) { + x <<= 1; + r -= 1; + } + return r; +} + +#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ |
