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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-13 12:02:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-13 12:02:29 +0000 |
commit | 751ac5be401fcb4b633a5ea3116de2f9d7452bbb (patch) | |
tree | 442d9b37f3c5f5d306a9eef7b35363b78ac1c5a3 /src/mt19937ar-cok | |
parent | Adding upstream version 0.36. (diff) | |
download | nwipe-751ac5be401fcb4b633a5ea3116de2f9d7452bbb.tar.xz nwipe-751ac5be401fcb4b633a5ea3116de2f9d7452bbb.zip |
Adding upstream version 0.37.upstream/0.37upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/mt19937ar-cok')
-rw-r--r-- | src/mt19937ar-cok/mt19937ar-cok.c | 140 | ||||
-rw-r--r-- | src/mt19937ar-cok/mt19937ar-cok.h | 25 |
2 files changed, 90 insertions, 75 deletions
diff --git a/src/mt19937ar-cok/mt19937ar-cok.c b/src/mt19937ar-cok/mt19937ar-cok.c index 63ef659..af8cc75 100644 --- a/src/mt19937ar-cok/mt19937ar-cok.c +++ b/src/mt19937ar-cok/mt19937ar-cok.c @@ -1,16 +1,16 @@ -/* - This code is modified for use in nwipe. +/* + 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) + 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. + All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions @@ -23,8 +23,8 @@ 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 + 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 @@ -48,77 +48,89 @@ #include <stdio.h> #include "mt19937ar-cok.h" -/* initializes state[N] with a seed */ -void init_genrand( twister_state_t* state, unsigned long s) +/* initializes state[MT_STATE_SIZE] 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; + int j; + state->array[0] = s & 0xffffffffUL; + for( j = 1; j < MT_STATE_SIZE; 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 ); + int j = 0; + int k = ( MT_STATE_SIZE > key_length ? MT_STATE_SIZE : 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; - } + { + 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 >= MT_STATE_SIZE ) + { + state->array[0] = state->array[MT_STATE_SIZE - 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; - } + for( k = MT_STATE_SIZE - 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 >= MT_STATE_SIZE ) + { + state->array[0] = state->array[MT_STATE_SIZE - 1]; + i = 1; + } } - state->array[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */ - state->left = 1; - state->initf = 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; + unsigned long* p = state->array; int j; - if( state->initf == 0) { init_genrand( state, 5489UL ); } - state->left = N; + // Ensures the generator is initialized + if( state->initf == 0 ) + { + init_genrand( state, 5489UL ); + } + state->left = MT_STATE_SIZE; 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]); + + for( j = MT_STATE_SIZE - MT_MIDDLE_WORD + 1; --j; p++ ) + { + *p = p[MT_MIDDLE_WORD] ^ TWIST( p[0], p[1] ); + } + for( j = MT_MIDDLE_WORD; --j; p++ ) + { + *p = p[MT_MIDDLE_WORD - MT_STATE_SIZE] ^ TWIST( p[0], p[1] ); + } + *p = p[MT_MIDDLE_WORD - MT_STATE_SIZE] ^ TWIST( p[0], state->array[0] ); } /* generates a random number on [0,0xffffffff]-interval */ @@ -126,14 +138,18 @@ unsigned long twister_genrand_int32( twister_state_t* state ) { unsigned long y; - if ( --state->left == 0 ) { next_state( state ); } + // Advance internal state if necessary + 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); + // Tempering + y ^= ( y >> 11 ); + y ^= ( y << 7 ) & 0x9d2c5680UL; + y ^= ( y << 15 ) & 0xefc60000UL; + y ^= ( y >> 18 ); return y; } diff --git a/src/mt19937ar-cok/mt19937ar-cok.h b/src/mt19937ar-cok/mt19937ar-cok.h index afcc873..202a0f5 100644 --- a/src/mt19937ar-cok/mt19937ar-cok.h +++ b/src/mt19937ar-cok/mt19937ar-cok.h @@ -1,30 +1,29 @@ /* - * mt19937ar-cok.h: The Mersenne Twister PRNG implementation for nwipe. - * + * mt19937ar-cok.h: The Mersenne Twister PRNG implementation for nwipe. */ #ifndef MT19937AR_H_ #define MT19937AR_H_ /* Period parameters */ -#define N 624 -#define M 397 -#define MATRIX_A 0x9908b0dfUL /* constant vector a */ +#define MT_STATE_SIZE 624 +#define MT_MIDDLE_WORD 397 +#define MATRIX_A 0x9908b0dfUL /* constant vector a */ #define UMASK 0x80000000UL /* most significant w-r bits */ #define LMASK 0x7fffffffUL /* least significant r bits */ -#define MIXBITS(u,v) ( ((u) & UMASK) | ((v) & LMASK) ) -#define TWIST(u,v) ((MIXBITS(u,v) >> 1) ^ ((v)&1UL ? MATRIX_A : 0UL)) +#define MIXBITS( u, v ) ( ( (u) &UMASK ) | ( (v) &LMASK ) ) +#define TWIST( u, v ) ( ( MIXBITS( u, v ) >> 1 ) ^ ( (v) &1UL ? MATRIX_A : 0UL ) ) typedef struct twister_state_t_ { - unsigned long array[N]; - int left; - int initf; - unsigned long *next; -} twister_state_t; + unsigned long array[MT_STATE_SIZE]; // Updated to use MT_STATE_SIZE + int left; + int initf; + unsigned long* next; +} twister_state_t; /* Initialize the MT state. ( 0 < key_length <= 624 ). */ -void twister_init( twister_state_t* state, unsigned long init_key[], unsigned long key_length); +void twister_init( twister_state_t* state, unsigned long init_key[], unsigned long key_length ); /* Generate a random integer on the [0,0xffffffff] interval. */ unsigned long twister_genrand_int32( twister_state_t* state ); |