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Diffstat (limited to '')
| -rw-r--r-- | src/mt19937ar-cok/mt19937ar-cok.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/src/mt19937ar-cok/mt19937ar-cok.c b/src/mt19937ar-cok/mt19937ar-cok.c new file mode 100644 index 0000000..63ef659 --- /dev/null +++ b/src/mt19937ar-cok/mt19937ar-cok.c @@ -0,0 +1,139 @@ +/* + This code is modified for use in nwipe. + + A C-program for MT19937, with initialization improved 2002/2/10. + Coded by Takuji Nishimura and Makoto Matsumoto. + This is a faster version by taking Shawn Cokus's optimization, + Matthe Bellew's simplification, Isaku Wada's real version. + + Before using, initialize the state by using init_genrand(seed) + or init_by_array(init_key, key_length). + + Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura, + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + 1. Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + 2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + 3. The names of its contributors may not be used to endorse or promote + products derived from this software without specific prior written + permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + + Any feedback is very welcome. + http://www.math.keio.ac.jp/matumoto/emt.html + email: matumoto@math.keio.ac.jp +*/ + +#include <stdio.h> +#include "mt19937ar-cok.h" + +/* initializes state[N] with a seed */ +void init_genrand( twister_state_t* state, unsigned long s) +{ + int j; + state->array[0]= s & 0xffffffffUL; + for( j = 1; j < N; j++ ) + { + state->array[j] = (1812433253UL * (state->array[j-1] ^ (state->array[j-1] >> 30)) + j); + state->array[j] &= 0xffffffffUL; /* for >32 bit machines */ + } + state->left = 1; + state->initf = 1; +} + + +void twister_init( twister_state_t* state, unsigned long init_key[], unsigned long key_length ) +{ + int i = 1; + int j = 0; + int k = ( N > key_length ? N : key_length ); + + init_genrand( state, 19650218UL ); + + for( ; k; k-- ) + { + state->array[i] = (state->array[i] ^ ((state->array[i-1] ^ (state->array[i-1] >> 30)) * 1664525UL)) + init_key[j] + j; + state->array[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */ + ++i; + ++j; + + if ( i >= N ) + { + state->array[0] = state->array[N-1]; + i = 1; + } + + if ( j >= key_length ) + { + j = 0; + } + } + + for( k = N -1; k; k-- ) + { + state->array[i] = (state->array[i] ^ ((state->array[i-1] ^ (state->array[i-1] >> 30)) * 1566083941UL)) - i; + state->array[i] &= 0xffffffffUL; + ++i; + + if ( i >= N ) + { + state->array[0] = state->array[N-1]; + i = 1; + } + } + + state->array[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */ + state->left = 1; + state->initf = 1; +} + +static void next_state( twister_state_t* state ) +{ + unsigned long *p = state->array; + int j; + + if( state->initf == 0) { init_genrand( state, 5489UL ); } + state->left = N; + state->next = state->array; + for( j = N - M + 1; --j; p++ ) { *p = p[M] ^ TWIST(p[0], p[1]); } + for( j = M; --j; p++ ) { *p = p[M-N] ^ TWIST(p[0], p[1]); } + *p = p[M-N] ^ TWIST(p[0], state->array[0]); +} + +/* generates a random number on [0,0xffffffff]-interval */ +unsigned long twister_genrand_int32( twister_state_t* state ) +{ + unsigned long y; + + if ( --state->left == 0 ) { next_state( state ); } + y = *state->next++; + + /* Tempering */ + y ^= (y >> 11); + y ^= (y << 7) & 0x9d2c5680UL; + y ^= (y << 15) & 0xefc60000UL; + y ^= (y >> 18); + + return y; +} |