0,0 → 1,36 |
#ifndef _ASM_GENERIC_BITOPS_FLS64_H_ |
#define _ASM_GENERIC_BITOPS_FLS64_H_ |
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#include <asm/types.h> |
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/** |
* 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 |
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#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */ |