xref: /openbmc/linux/include/asm-generic/bitops/builtin-fls.h (revision 048fa2df92c325cb4425dccd66c8922c8342b507)
1*048fa2dfSCatalin Marinas #ifndef _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
2*048fa2dfSCatalin Marinas #define _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
3*048fa2dfSCatalin Marinas 
4*048fa2dfSCatalin Marinas /**
5*048fa2dfSCatalin Marinas  * fls - find last (most-significant) bit set
6*048fa2dfSCatalin Marinas  * @x: the word to search
7*048fa2dfSCatalin Marinas  *
8*048fa2dfSCatalin Marinas  * This is defined the same way as ffs.
9*048fa2dfSCatalin Marinas  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
10*048fa2dfSCatalin Marinas  */
11*048fa2dfSCatalin Marinas static __always_inline int fls(int x)
12*048fa2dfSCatalin Marinas {
13*048fa2dfSCatalin Marinas 	return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
14*048fa2dfSCatalin Marinas }
15*048fa2dfSCatalin Marinas 
16*048fa2dfSCatalin Marinas #endif
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