diff options
| -rw-r--r-- | stc/mt19937.h | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/stc/mt19937.h b/stc/mt19937.h index 46e1b7c6..4839c478 100644 --- a/stc/mt19937.h +++ b/stc/mt19937.h @@ -81,21 +81,21 @@ static inline mt19937_t mt19937_default(void) { /* generates a random number on [0,0xffffffff]-interval */ static inline uint32_t mt19937_rand(mt19937_t *state) { - enum {N = mt19937_N, M = mt19937_M}; + enum {N = mt19937_N, M = mt19937_M, N_1 = N-1, N_M = N-M}; uint32_t y, *arr = state->arr; if (state->idx >= N) { /* generate N words at one time */ int k; - for (k = 0; k < (N - M); ++k) { + for (k = 0; k < N_M; ++k) { y = (arr[k] & 0x80000000) | (arr[k + 1] & 0x7fffffff); arr[k] = arr[k + M] ^ (y >> 1) ^ ((y & 1) * 0x9908b0df); } - for (; k < N - 1; ++k) { + for (; k < N_1; ++k) { y = (arr[k] & 0x80000000) | (arr[k + 1] & 0x7fffffff); - arr[k] = arr[k - (N - M)] ^ (y >> 1) ^ ((y & 1) * 0x9908b0df); + arr[k] = arr[k - N_M] ^ (y >> 1) ^ ((y & 1) * 0x9908b0df); } - y = (arr[N - 1] & 0x80000000) | (arr[0] & 0x7fffffff); - arr[N - 1] = arr[M - 1] ^ (y >> 1) ^ ((y & 1) * 0x9908b0df); + y = (arr[N_1] & 0x80000000) | (arr[0] & 0x7fffffff); + arr[N_1] = arr[M - 1] ^ (y >> 1) ^ ((y & 1) * 0x9908b0df); state->idx = 0; } |