/* SPDX-License-Identifier: GPL-2.0 */ | |
#ifndef _ASM_GENERIC_BITOPS_FLS_H_ | |
#define _ASM_GENERIC_BITOPS_FLS_H_ | |
/** | |
* fls - find last (most-significant) bit set | |
* @x: the word to search | |
* | |
* This is defined the same way as ffs. | |
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. | |
*/ | |
static __always_inline int fls(int x) | |
{ | |
int r = 32; | |
if (!x) | |
return 0; | |
if (!(x & 0xffff0000u)) { | |
x <<= 16; | |
r -= 16; | |
} | |
if (!(x & 0xff000000u)) { | |
x <<= 8; | |
r -= 8; | |
} | |
if (!(x & 0xf0000000u)) { | |
x <<= 4; | |
r -= 4; | |
} | |
if (!(x & 0xc0000000u)) { | |
x <<= 2; | |
r -= 2; | |
} | |
if (!(x & 0x80000000u)) { | |
x <<= 1; | |
r -= 1; | |
} | |
return r; | |
} | |
#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ |