Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / include / asm-generic / bitops / __ffs.h
blob39e56e1c72032413a082d6f336e01ba5d3d8be92
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_GENERIC_BITOPS___FFS_H_
3 #define _ASM_GENERIC_BITOPS___FFS_H_
5 #include <asm/types.h>
7 /**
8 * __ffs - find first bit in word.
9 * @word: The word to search
11 * Undefined if no bit exists, so code should check against 0 first.
13 static __always_inline unsigned long __ffs(unsigned long word)
15 int num = 0;
17 #if BITS_PER_LONG == 64
18 if ((word & 0xffffffff) == 0) {
19 num += 32;
20 word >>= 32;
22 #endif
23 if ((word & 0xffff) == 0) {
24 num += 16;
25 word >>= 16;
27 if ((word & 0xff) == 0) {
28 num += 8;
29 word >>= 8;
31 if ((word & 0xf) == 0) {
32 num += 4;
33 word >>= 4;
35 if ((word & 0x3) == 0) {
36 num += 2;
37 word >>= 2;
39 if ((word & 0x1) == 0)
40 num += 1;
41 return num;
44 #endif /* _ASM_GENERIC_BITOPS___FFS_H_ */