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#ifndef TINYMT32_H
#define TINYMT32_H
/**
* @file tinymt32.h
*
* @brief Tiny Mersenne Twister only 127 bit internal state
*
* @author Mutsuo Saito (Hiroshima University)
* @author Makoto Matsumoto (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
*/
#include <stdint.h>
#include <inttypes.h>
#define TINYMT32_MEXP 127
#define TINYMT32_SH0 1
#define TINYMT32_SH1 10
#define TINYMT32_SH8 8
#define TINYMT32_MASK UINT32_C(0x7fffffff)
#define TINYMT32_MUL (1.0f / 16777216.0f)
#ifdef __cplusplus
extern "C" {
#endif
/**
* tinymt32 internal state vector and parameters
*/
struct TINYMT32_T {
uint32_t status[4];
uint32_t mat1;
uint32_t mat2;
uint32_t tmat;
};
typedef struct TINYMT32_T tinymt32_t;
void tinymt32_init(tinymt32_t *random, uint32_t seed);
void tinymt32_init_by_array(tinymt32_t *random, uint32_t init_key[],
int key_length);
inline static int tinymt32_get_mexp(tinymt32_t *random)
{
(void) random;
return TINYMT32_MEXP;
}
/**
* This function changes internal state of tinymt32.
* Users should not call this function directly.
* @param random tinymt internal status
*/
inline static void tinymt32_next_state(tinymt32_t *random)
{
uint32_t x;
uint32_t y;
y = random->status[3];
x = (random->status[0] & TINYMT32_MASK)
^ random->status[1]
^ random->status[2];
x ^= (x << TINYMT32_SH0);
y ^= (y >> TINYMT32_SH0) ^ x;
random->status[0] = random->status[1];
random->status[1] = random->status[2];
random->status[2] = x ^ (y << TINYMT32_SH1);
random->status[3] = y;
random->status[1] ^= -((int32_t)(y & 1)) & random->mat1;
random->status[2] ^= -((int32_t)(y & 1)) & random->mat2;
}
/**
* This function outputs 32-bit unsigned integer from internal state.
* Users should not call this function directly.
* @param random tinymt internal status
* @return 32-bit unsigned pseudorandom number
*/
inline static uint32_t tinymt32_temper(tinymt32_t *random)
{
uint32_t t0, t1;
t0 = random->status[3];
t1 = random->status[0] + (random->status[2] >> TINYMT32_SH8);
t0 ^= t1;
t0 ^= -((int32_t)(t1 & 1)) & random->tmat;
return t0;
}
/**
* This function outputs floating point number from internal state.
* Users should not call this function directly.
* @param random tinymt internal status
* @return floating point number r (1.0 <= r < 2.0)
*/
inline static float tinymt32_temper_conv(tinymt32_t *random)
{
uint32_t t0, t1;
union {
uint32_t u;
float f;
} conv;
t0 = random->status[3];
t1 = random->status[0] + (random->status[2] >> TINYMT32_SH8);
t0 ^= t1;
conv.u = ((t0 ^ (-((int32_t)(t1 & 1)) & random->tmat)) >> 9)
| UINT32_C(0x3f800000);
return conv.f;
}
/**
* This function outputs floating point number from internal state.
* Users should not call this function directly.
* @param random tinymt internal status
* @return floating point number r (1.0 < r < 2.0)
*/
inline static float tinymt32_temper_conv_open(tinymt32_t *random)
{
uint32_t t0, t1;
union {
uint32_t u;
float f;
} conv;
t0 = random->status[3];
t1 = random->status[0] + (random->status[2] >> TINYMT32_SH8);
t0 ^= t1;
conv.u = ((t0 ^ (-((int32_t)(t1 & 1)) & random->tmat)) >> 9)
| UINT32_C(0x3f800001);
return conv.f;
}
/**
* This function outputs 32-bit unsigned integer from internal state.
* @param random tinymt internal status
* @return 32-bit unsigned integer r (0 <= r < 2^32)
*/
inline static uint32_t tinymt32_generate_uint32(tinymt32_t *random)
{
tinymt32_next_state(random);
return tinymt32_temper(random);
}
/**
* This function outputs floating point number from internal state.
* This function is implemented using multiplying by (1 / 2^24).
* floating point multiplication is faster than using union trick in
* my Intel CPU.
* @param random tinymt internal status
* @return floating point number r (0.0 <= r < 1.0)
*/
inline static float tinymt32_generate_float(tinymt32_t *random)
{
tinymt32_next_state(random);
return (tinymt32_temper(random) >> 8) * TINYMT32_MUL;
}
/**
* This function outputs floating point number from internal state.
* This function is implemented using union trick.
* @param random tinymt internal status
* @return floating point number r (1.0 <= r < 2.0)
*/
inline static float tinymt32_generate_float12(tinymt32_t *random)
{
tinymt32_next_state(random);
return tinymt32_temper_conv(random);
}
/**
* This function outputs floating point number from internal state.
* This function is implemented using union trick.
* @param random tinymt internal status
* @return floating point number r (0.0 <= r < 1.0)
*/
inline static float tinymt32_generate_float01(tinymt32_t *random)
{
tinymt32_next_state(random);
return tinymt32_temper_conv(random) - 1.0f;
}
/**
* This function outputs floating point number from internal state.
* This function may return 1.0 and never returns 0.0.
* @param random tinymt internal status
* @return floating point number r (0.0 < r <= 1.0)
*/
inline static float tinymt32_generate_floatOC(tinymt32_t *random)
{
tinymt32_next_state(random);
return 1.0f - tinymt32_generate_float(random);
}
/**
* This function outputs floating point number from internal state.
* This function returns neither 0.0 nor 1.0.
* @param random tinymt internal status
* @return floating point number r (0.0 < r < 1.0)
*/
inline static float tinymt32_generate_floatOO(tinymt32_t *random)
{
tinymt32_next_state(random);
return tinymt32_temper_conv_open(random) - 1.0f;
}
/**
* This function outputs double precision floating point number from
* internal state. The returned value has 32-bit precision.
* In other words, this function makes one double precision floating point
* number from one 32-bit unsigned integer.
* @param random tinymt internal status
* @return floating point number r (0.0 < r <= 1.0)
*/
inline static double tinymt32_generate_32double(tinymt32_t *random)
{
tinymt32_next_state(random);
return tinymt32_temper(random) * (1.0 / 4294967296.0);
}
#ifdef __cplusplus
}
#endif
#endif