diff options
Diffstat (limited to 'src/common/mt_rand.c')
| -rw-r--r-- | src/common/mt_rand.c | 87 |
1 files changed, 43 insertions, 44 deletions
diff --git a/src/common/mt_rand.c b/src/common/mt_rand.c index fc9a9ec..627d9dd 100644 --- a/src/common/mt_rand.c +++ b/src/common/mt_rand.c @@ -48,72 +48,71 @@ #include <time.h> #include "mt_rand.h" -#define N (624) /* length of state vector */ -#define M (397) /* a period parameter */ -#define K (0x9908B0DFU) /* a magic constant */ -#define hiBit(u) ((u) & 0x80000000U) /* mask all but highest bit of u */ -#define loBit(u) ((u) & 0x00000001U) /* mask all but lowest bit of u */ -#define loBits(u) ((u) & 0x7FFFFFFFU) /* mask the highest bit of u */ -#define mixBits(u, v) (hiBit(u)|loBits(v)) /* move hi bit of u to hi bit of v */ - -static unsigned long state[N+1]; /* state vector + 1 extra to not violate ANSI C */ -static unsigned long *next; /* next random value is computed from here */ -static int left = -1; /* can *next++ this many times before reloading */ - - -void mt_seed(unsigned long seed) +#define N (624) /* length of state vector */ +#define M (397) /* a period parameter */ +#define K (0x9908B0DFU) /* a magic constant */ +#define hiBit(u) ((u) & 0x80000000U) /* mask all but highest bit of u */ +#define loBit(u) ((u) & 0x00000001U) /* mask all but lowest bit of u */ +#define loBits(u) ((u) & 0x7FFFFFFFU) /* mask the highest bit of u */ +#define mixBits(u, v) (hiBit(u)|loBits(v)) /* move hi bit of u to hi bit of v */ + +static unsigned long state[N + 1]; /* state vector + 1 extra to not violate ANSI C */ +static unsigned long *next; /* next random value is computed from here */ +static int left = -1; /* can *next++ this many times before reloading */ + +void mt_seed (unsigned long seed) { register unsigned long x = (seed | 1U) & 0xFFFFFFFFU, *s = state; - register int j; + register int j; - for(left=0, *s++=x, j=N; --j; - *s++ = (x*=69069U) & 0xFFFFFFFFU); + for (left = 0, *s++ = x, j = N; --j; *s++ = (x *= 69069U) & 0xFFFFFFFFU); } - -unsigned long mt_reload(void) +unsigned long mt_reload (void) { - register unsigned long *p0=state, *p2=state+2, *pM=state+M, s0, s1; - register int j; + register unsigned long *p0 = state, *p2 = state + 2, *pM = + state + M, s0, s1; + register int j; - if(left < -1) - mt_seed(time(NULL)); + if (left < -1) + mt_seed (time (NULL)); - left=N-1, next=state+1; + left = N - 1, next = state + 1; - for(s0=state[0], s1=state[1], j=N-M+1; --j; s0=s1, s1=*p2++) - *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U); + for (s0 = state[0], s1 = state[1], j = N - M + 1; --j; + s0 = s1, s1 = *p2++) + *p0++ = *pM++ ^ (mixBits (s0, s1) >> 1) ^ (loBit (s1) ? K : 0U); - for(pM=state, j=M; --j; s0=s1, s1=*p2++) - *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U); + for (pM = state, j = M; --j; s0 = s1, s1 = *p2++) + *p0++ = *pM++ ^ (mixBits (s0, s1) >> 1) ^ (loBit (s1) ? K : 0U); - s1=state[0], *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U); + s1 = state[0], *p0 = + *pM ^ (mixBits (s0, s1) >> 1) ^ (loBit (s1) ? K : 0U); s1 ^= (s1 >> 11); - s1 ^= (s1 << 7) & 0x9D2C5680U; + s1 ^= (s1 << 7) & 0x9D2C5680U; s1 ^= (s1 << 15) & 0xEFC60000U; - return(s1 ^ (s1 >> 18)); + return (s1 ^ (s1 >> 18)); } - -unsigned long mt_random(void) +unsigned long mt_random (void) { unsigned long y; - if(--left < 0) - return(mt_reload()); + if (--left < 0) + return (mt_reload ()); - y = *next++; + y = *next++; y ^= (y >> 11); - y ^= (y << 7) & 0x9D2C5680U; + y ^= (y << 7) & 0x9D2C5680U; y ^= (y << 15) & 0xEFC60000U; - return(y ^ (y >> 18)); + return (y ^ (y >> 18)); } -int mt_rand(void) { - unsigned long r = mt_random(); - while (r >> 16) - r = (r & 0xFFFF) + (r >> 16); +int mt_rand (void) +{ + unsigned long r = mt_random (); + while (r >> 16) + r = (r & 0xFFFF) + (r >> 16); - return(r); + return (r); } - |