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author | Stefano Babic <sbabic@denx.de> | 2015-11-12 17:13:26 +0100 |
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committer | Stefano Babic <sbabic@denx.de> | 2015-11-12 17:13:26 +0100 |
commit | 5f5620ab2679608f94b3a77e51c77d0a770103bd (patch) | |
tree | ec983c06d2f62384909968bb870add121b8a1502 /include/asm-generic/bitops/fls64.h | |
parent | 78e9ca52edaab74ad645d719676ff4c24d2f462c (diff) | |
parent | 038be18fd95aa6283eafb85ceabc0b880976424b (diff) | |
download | u-boot-5f5620ab2679608f94b3a77e51c77d0a770103bd.tar.gz |
Merge git://git.denx.de/u-boot
Diffstat (limited to 'include/asm-generic/bitops/fls64.h')
-rw-r--r-- | include/asm-generic/bitops/fls64.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/fls64.h b/include/asm-generic/bitops/fls64.h new file mode 100644 index 0000000000..b097cf8444 --- /dev/null +++ b/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_ */ |