xref: /openbmc/linux/include/asm-generic/bitops/builtin-__fls.h (revision 498495dba268b20e8eadd7fe93c140c68b6cc9d2)
1*b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
2048fa2dfSCatalin Marinas #ifndef _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
3048fa2dfSCatalin Marinas #define _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
4048fa2dfSCatalin Marinas 
5048fa2dfSCatalin Marinas /**
6048fa2dfSCatalin Marinas  * __fls - find last (most-significant) set bit in a long word
7048fa2dfSCatalin Marinas  * @word: the word to search
8048fa2dfSCatalin Marinas  *
9048fa2dfSCatalin Marinas  * Undefined if no set bit exists, so code should check against 0 first.
10048fa2dfSCatalin Marinas  */
__fls(unsigned long word)11048fa2dfSCatalin Marinas static __always_inline unsigned long __fls(unsigned long word)
12048fa2dfSCatalin Marinas {
13048fa2dfSCatalin Marinas 	return (sizeof(word) * 8) - 1 - __builtin_clzl(word);
14048fa2dfSCatalin Marinas }
15048fa2dfSCatalin Marinas 
16048fa2dfSCatalin Marinas #endif
17