asm-generic/bitops/builtin-__fls.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
0003 #define _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
0004
0005 /**
0006  * __fls - find last (most-significant) set bit in a long word
0007  * @word: the word to search
0008  *
0009  * Undefined if no set bit exists, so code should check against 0 first.
0010  */
0011 static __always_inline unsigned long __fls(unsigned long word)
0012 {
0013     return (sizeof(word) * 8) - 1 - __builtin_clzl(word);
0014 }
0015
0016 #endif