| Jens Axboe | 064c636 | 2008-06-02 09:19:37 +0200 | [diff] [blame] | 1 | #ifndef FIO_FFZ_H |
| 2 | #define FIO_FFZ_H | ||||
| 3 | |||||
| 4 | static inline int __ffs(int word) | ||||
| 5 | { | ||||
| Jens Axboe | 0917444 | 2008-06-02 09:57:41 +0200 | [diff] [blame^] | 6 | int r = 0; |
| Jens Axboe | 064c636 | 2008-06-02 09:19:37 +0200 | [diff] [blame] | 7 | |
| 8 | if (!(word & 0xffff)) { | ||||
| 9 | word >>= 16; | ||||
| 10 | r += 16; | ||||
| 11 | } | ||||
| 12 | if (!(word & 0xff)) { | ||||
| 13 | word >>= 8; | ||||
| 14 | r += 8; | ||||
| 15 | } | ||||
| 16 | if (!(word & 0xf)) { | ||||
| 17 | word >>= 4; | ||||
| 18 | r += 4; | ||||
| 19 | } | ||||
| 20 | if (!(word & 3)) { | ||||
| 21 | word >>= 2; | ||||
| 22 | r += 2; | ||||
| 23 | } | ||||
| 24 | if (!(word & 1)) { | ||||
| 25 | word >>= 1; | ||||
| 26 | r += 1; | ||||
| 27 | } | ||||
| 28 | |||||
| 29 | return r; | ||||
| 30 | } | ||||
| 31 | |||||
| 32 | static inline int ffz(unsigned int bitmask) | ||||
| 33 | { | ||||
| Jens Axboe | 0917444 | 2008-06-02 09:57:41 +0200 | [diff] [blame^] | 34 | return __ffs(~bitmask); |
| Jens Axboe | 064c636 | 2008-06-02 09:19:37 +0200 | [diff] [blame] | 35 | } |
| 36 | |||||
| 37 | #endif | ||||