tinymt32.c File Reference

Detailed Description

Tiny Mersenne Twister only 127 bit internal state.

Author

Mutsuo Saito (Hiroshima University)

Makoto Matsumoto (The University of Tokyo)

Copyright (C) 2011 Mutsuo Saito, Makoto Matsumoto, Hiroshima University and The University of Tokyo. All rights reserved.

The 3-clause BSD License is applied to this software, see LICENSE.txt

Definition in file tinymt32.c.

Functions
static uint32_t	ini_func1 (uint32_t x)
static uint32_t	ini_func2 (uint32_t x)
static void	period_certification (tinymt32_t *random)
void	tinymt32_init (tinymt32_t *random, uint32_t seed)
void	tinymt32_init_by_array (tinymt32_t *random, uint32_t init_key[], int key_length)

Function Documentation

ini_func1()

static uint32_t ini_func1 ( uint32_t  x )

static

This function represents a function used in the initialization by init_by_array

Parameters

x	32-bit integer

Returns

32-bit integer

Definition at line 26 of file tinymt32.c.

                                      {
    return (x ^ (x >> 27)) * UINT32_C(1664525);
}

Referenced by tinymt32_init_by_array().

Here is the caller graph for this function:

ini_func2()

static uint32_t ini_func2 ( uint32_t  x )

static

This function represents a function used in the initialization by init_by_array

Parameters

x	32-bit integer

Returns

32-bit integer

Definition at line 36 of file tinymt32.c.

                                      {
    return (x ^ (x >> 27)) * UINT32_C(1566083941);
}

Referenced by tinymt32_init_by_array().

Here is the caller graph for this function:

period_certification()

static void period_certification ( tinymt32_t *  random )

static

This function certificate the period of 2^127-1.

Parameters

random

tinymt state vector.

Definition at line 44 of file tinymt32.c.

                                                      {
    if ((random->status[0] & TINYMT32_MASK) == 0 &&
        random->status[1] == 0 &&
        random->status[2] == 0 &&
        random->status[3] == 0) {
        random->status[0] = 'T';
        random->status[1] = 'I';
        random->status[2] = 'N';
        random->status[3] = 'Y';
    }
}

Referenced by tinymt32_init(), and tinymt32_init_by_array().

Here is the caller graph for this function:

tinymt32_init()

void tinymt32_init	(	tinymt32_t *	random,
		uint32_t	seed
	)

This function initializes the internal state array with a 32-bit unsigned integer seed.

Parameters

random	tinymt state vector.
seed	a 32-bit unsigned integer used as a seed.

Definition at line 62 of file tinymt32.c.

                                                       {
    random->status[0] = seed;
    random->status[1] = random->mat1;
    random->status[2] = random->mat2;
    random->status[3] = random->tmat;
    for (unsigned int i = 1; i < MIN_LOOP; i++) {
        random->status[i & 3] ^= i + UINT32_C(1812433253)
            * (random->status[(i - 1) & 3]
               ^ (random->status[(i - 1) & 3] >> 30));
    }
    period_certification(random);
    for (unsigned int i = 0; i < PRE_LOOP; i++) {
        tinymt32_next_state(random);
    }
}

Referenced by configureRusefiLuaHooks(), and initLaunchControl().

Here is the call graph for this function:

Here is the caller graph for this function:

tinymt32_init_by_array()

void tinymt32_init_by_array	(	tinymt32_t *	random,
		uint32_t	init_key[],
		int	key_length
	)

This function initializes the internal state array, with an array of 32-bit unsigned integers used as seeds

Parameters

random	tinymt state vector.
init_key	the array of 32-bit integers, used as a seed.
key_length	the length of init_key.

Definition at line 85 of file tinymt32.c.

                                            {
    const unsigned int lag = 1;
    const unsigned int mid = 1;
    const unsigned int size = 4;
    unsigned int i, j;
    unsigned int count;
    uint32_t r;
    uint32_t * st = &random->status[0];
 
    st[0] = 0;
    st[1] = random->mat1;
    st[2] = random->mat2;
    st[3] = random->tmat;
    if (key_length + 1 > MIN_LOOP) {
        count = (unsigned int)key_length + 1;
    } else {
        count = MIN_LOOP;
    }
    r = ini_func1(st[0] ^ st[mid % size]
                  ^ st[(size - 1) % size]);
    st[mid % size] += r;
    r += (unsigned int)key_length;
    st[(mid + lag) % size] += r;
    st[0] = r;
    count--;
    for (i = 1, j = 0; (j < count) && (j < (unsigned int)key_length); j++) {
        r = ini_func1(st[i % size]
                      ^ st[(i + mid) % size]
                      ^ st[(i + size - 1) % size]);
        st[(i + mid) % size] += r;
        r += init_key[j] + i;
        st[(i + mid + lag) % size] += r;
        st[i % size] = r;
        i = (i + 1) % size;
    }
    for (; j < count; j++) {
        r = ini_func1(st[i % size]
                      ^ st[(i + mid) % size]
                      ^ st[(i + size - 1) % size]);
        st[(i + mid) % size] += r;
        r += i;
        st[(i + mid + lag) % size] += r;
        st[i % size] = r;
        i = (i + 1) % size;
    }
    for (j = 0; j < size; j++) {
        r = ini_func2(st[i % size]
                      + st[(i + mid) % size]
                      + st[(i + size - 1) % size]);
        st[(i + mid) % size] ^= r;
        r -= i;
        st[(i + mid + lag) % size] ^= r;
        st[i % size] = r;
        i = (i + 1) % size;
    }
    period_certification(random);
    for (i = 0; i < PRE_LOOP; i++) {
        tinymt32_next_state(random);
    }
}

Here is the call graph for this function:

Go to the source code of this file.