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| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2013-07-27 22:15:10 +0000 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2013-07-27 22:15:10 +0000 |
| commit | b5875be0451b92bdd99663c8305ae46bd6a7d90c (patch) | |
| tree | 68a6a5f79ac618c79ba3777c21faaea9aec2f0b4 /libdde-linux26/contrib/include/asm-generic/bitops/fls.h | |
| parent | ce6a36c7f7c88e7ca0fda816f9282237bb86829d (diff) | |
| parent | 7996a3d79d55b7f879dfd62e202bbfe2963718d3 (diff) | |
Merge branch '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_ */ |
