| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _ASM_GENERIC_BITOPS_FFS_H_ |
| #define _ASM_GENERIC_BITOPS_FFS_H_ |
| |
| /** |
| * ffs - find first bit set |
| * @x: the word to search |
| * |
| * This is defined the same way as |
| * the libc and compiler builtin ffs routines, therefore |
| * differs in spirit from the above ffz (man ffs). |
| */ |
| static inline int ffs(int x) |
| { |
| int r = 1; |
| |
| if (!x) |
| return 0; |
| if (!(x & 0xffff)) { |
| x >>= 16; |
| r += 16; |
| } |
| if (!(x & 0xff)) { |
| x >>= 8; |
| r += 8; |
| } |
| if (!(x & 0xf)) { |
| x >>= 4; |
| r += 4; |
| } |
| if (!(x & 3)) { |
| x >>= 2; |
| r += 2; |
| } |
| if (!(x & 1)) { |
| x >>= 1; |
| r += 1; |
| } |
| return r; |
| } |
| |
| #endif /* _ASM_GENERIC_BITOPS_FFS_H_ */ |