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author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2013-07-27 22:15:01 +0000 |
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committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2013-07-27 22:15:01 +0000 |
commit | 7996a3d79d55b7f879dfd62e202bbfe2963718d3 (patch) | |
tree | 8d9f6759fec4099b9be503c11c7ed174f7204980 /libdde-linux26/contrib/include/asm-generic/bitops/__ffs.h | |
parent | 4fbe7358c7747a9165f776eb19addbb9baf7def2 (diff) |
really properly move files
Diffstat (limited to 'libdde-linux26/contrib/include/asm-generic/bitops/__ffs.h')
-rw-r--r-- | libdde-linux26/contrib/include/asm-generic/bitops/__ffs.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/libdde-linux26/contrib/include/asm-generic/bitops/__ffs.h b/libdde-linux26/contrib/include/asm-generic/bitops/__ffs.h new file mode 100644 index 00000000..937d7c43 --- /dev/null +++ b/libdde-linux26/contrib/include/asm-generic/bitops/__ffs.h @@ -0,0 +1,43 @@ +#ifndef _ASM_GENERIC_BITOPS___FFS_H_ +#define _ASM_GENERIC_BITOPS___FFS_H_ + +#include <asm/types.h> + +/** + * __ffs - find first bit in word. + * @word: The word to search + * + * Undefined if no bit exists, so code should check against 0 first. + */ +static __always_inline unsigned long __ffs(unsigned long word) +{ + int num = 0; + +#if BITS_PER_LONG == 64 + if ((word & 0xffffffff) == 0) { + num += 32; + word >>= 32; + } +#endif + if ((word & 0xffff) == 0) { + num += 16; + word >>= 16; + } + if ((word & 0xff) == 0) { + num += 8; + word >>= 8; + } + if ((word & 0xf) == 0) { + num += 4; + word >>= 4; + } + if ((word & 0x3) == 0) { + num += 2; + word >>= 2; + } + if ((word & 0x1) == 0) + num += 1; + return num; +} + +#endif /* _ASM_GENERIC_BITOPS___FFS_H_ */ |