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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/fls64.h | |
| parent | 38c2c2458e3f4ecb329ff35621806252aac209b9 (diff) | |
| parent | 8df772b3c665e663f6f9d2a70f9c691590bd3f91 (diff) | |
Merge branch 'dde' into upstream-merged
Diffstat (limited to 'libdde_linux26/contrib/include/asm-generic/bitops/fls64.h')
| -rw-r--r-- | libdde_linux26/contrib/include/asm-generic/bitops/fls64.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/libdde_linux26/contrib/include/asm-generic/bitops/fls64.h b/libdde_linux26/contrib/include/asm-generic/bitops/fls64.h new file mode 100644 index 00000000..b097cf84 --- /dev/null +++ b/libdde_linux26/contrib/include/asm-generic/bitops/fls64.h @@ -0,0 +1,36 @@ +#ifndef _ASM_GENERIC_BITOPS_FLS64_H_ +#define _ASM_GENERIC_BITOPS_FLS64_H_ + +#include <asm/types.h> + +/** + * fls64 - find last set bit in a 64-bit word + * @x: the word to search + * + * This is defined in a similar way as the libc and compiler builtin + * ffsll, but returns the position of the most significant set bit. + * + * fls64(value) returns 0 if value is 0 or the position of the last + * set bit if value is nonzero. The last (most significant) bit is + * at position 64. + */ +#if BITS_PER_LONG == 32 +static __always_inline int fls64(__u64 x) +{ + __u32 h = x >> 32; + if (h) + return fls(h) + 32; + return fls(x); +} +#elif BITS_PER_LONG == 64 +static __always_inline int fls64(__u64 x) +{ + if (x == 0) + return 0; + return __fls(x) + 1; +} +#else +#error BITS_PER_LONG not 32 or 64 +#endif + +#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */ |
