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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 | 43 |
1 files changed, 43 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..a60a7ccb --- /dev/null +++ b/libdde-linux26/contrib/include/asm-generic/bitops/__fls.h @@ -0,0 +1,43 @@ +#ifndef _ASM_GENERIC_BITOPS___FLS_H_ +#define _ASM_GENERIC_BITOPS___FLS_H_ + +#include <asm/types.h> + +/** + * __fls - find last (most-significant) set bit in a long word + * @word: the word to search + * + * Undefined if no set bit exists, so code should check against 0 first. + */ +static __always_inline unsigned long __fls(unsigned long word) +{ + int num = BITS_PER_LONG - 1; + +#if BITS_PER_LONG == 64 + if (!(word & (~0ul << 32))) { + num -= 32; + word <<= 32; + } +#endif + if (!(word & (~0ul << (BITS_PER_LONG-16)))) { + num -= 16; + word <<= 16; + } + if (!(word & (~0ul << (BITS_PER_LONG-8)))) { + num -= 8; + word <<= 8; + } + if (!(word & (~0ul << (BITS_PER_LONG-4)))) { + num -= 4; + word <<= 4; + } + if (!(word & (~0ul << (BITS_PER_LONG-2)))) { + num -= 2; + word <<= 2; + } + if (!(word & (~0ul << (BITS_PER_LONG-1)))) + num -= 1; + return num; +} + +#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */ |
