diff options
author | Zheng Da <zhengda1936@gmail.com> | 2009-12-06 05:26:23 +0100 |
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committer | Zheng Da <zhengda1936@gmail.com> | 2009-12-06 05:26:23 +0100 |
commit | 8a6d48c0542876eb3acfc0970c0ab7872db08d5f (patch) | |
tree | 496e78bc728317ea779781b92f897d16936ee231 /libdde_linux26/contrib/include/asm-generic/bitops/fls.h | |
parent | b4bffcfcdf3ab7a55d664e9aa5907f88da503f38 (diff) |
check in the original version of dde linux26.
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_ */ |