1#ifndef _ASM_GENERIC_BITOPS_FLS64_H_ 2#define _ASM_GENERIC_BITOPS_FLS64_H_ 3 4#include <asm/types.h> 5 6/** 7 * fls64 - find last set bit in a 64-bit word 8 * @x: the word to search 9 * 10 * This is defined in a similar way as the libc and compiler builtin 11 * ffsll, but returns the position of the most significant set bit. 12 * 13 * fls64(value) returns 0 if value is 0 or the position of the last 14 * set bit if value is nonzero. The last (most significant) bit is 15 * at position 64. 16 */ 17#if BITS_PER_LONG == 32 18static __always_inline int fls64(__u64 x) 19{ 20 __u32 h = x >> 32; 21 if (h) 22 return fls(h) + 32; 23 return fls(x); 24} 25#elif BITS_PER_LONG == 64 26static __always_inline int fls64(__u64 x) 27{ 28 if (x == 0) 29 return 0; 30 return __fls(x) + 1; 31} 32#else 33#error BITS_PER_LONG not 32 or 64 34#endif 35 36#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */ 37