| Chris Wilson | 376b813 | 2016-07-03 09:42:38 +0100 | [diff] [blame^] | 1 | #include "igt_rand.h" |
| 2 | |||||
| 3 | static uint32_t state = 0x12345678; | ||||
| 4 | |||||
| 5 | uint32_t | ||||
| 6 | hars_petruska_f54_1_random_seed(uint32_t new_state) | ||||
| 7 | { | ||||
| 8 | uint32_t old_state = state; | ||||
| 9 | state = new_state; | ||||
| 10 | return old_state; | ||||
| 11 | } | ||||
| 12 | |||||
| 13 | uint32_t | ||||
| 14 | hars_petruska_f54_1_random_unsafe(void) | ||||
| 15 | { | ||||
| 16 | #define rol(x,k) ((x << k) | (x >> (32-k))) | ||||
| 17 | return state = (state ^ rol (state, 5) ^ rol (state, 24)) + 0x37798849; | ||||
| 18 | #undef rol | ||||
| 19 | } | ||||