/**

 * @file  SFMT.c

 * @brief SIMD oriented Fast Mersenne Twister(SFMT)

 *

 * @author Mutsuo Saito (Hiroshima University)

 * @author Makoto Matsumoto (Hiroshima University)

 *

 * Copyright (C) 2006, 2007 Mutsuo Saito, Makoto Matsumoto and Hiroshima

 * University.

 * Copyright (C) 2012 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

 */

#if defined(__cplusplus)

extern "C" {

#endif

#include <string.h>

#include <assert.h>

#include "SFMT.h"

#include "SFMT-params.h"

#include "SFMT-common.h"

#if defined(__BIG_ENDIAN__) && !defined(__amd64) && !defined(BIG_ENDIAN64)

#define BIG_ENDIAN64 1

#endif

#if defined(HAVE_ALTIVEC) && !defined(BIG_ENDIAN64)

#define BIG_ENDIAN64 1

#endif

#if defined(ONLY64) && !defined(BIG_ENDIAN64)

  #if defined(__GNUC__)

    #error "-DONLY64 must be specified with -DBIG_ENDIAN64"

  #endif

#undef ONLY64

#endif

/**

 * parameters used by sse2.

 */

#ifdef HAVE_SSE2

static const w128_t sse2_param_mask = {{SFMT_MSK1, SFMT_MSK2,

          SFMT_MSK3, SFMT_MSK4}};

#endif

/*----------------

  STATIC FUNCTIONS

  ----------------*/

inline static int idxof(int i);

inline static void gen_rand_array(sfmt_t * sfmt, w128_t *array, int size);

inline static uint32_t func1(uint32_t x);

inline static uint32_t func2(uint32_t x);

static void period_certification(sfmt_t * sfmt);

#if defined(BIG_ENDIAN64) && !defined(ONLY64)

inline static void swap(w128_t *array, int size);

#endif

#if defined(HAVE_ALTIVEC)

  #include "SFMT-alti.h"

#elif defined(HAVE_SSE2)

  #include "SFMT-sse2.h"

#endif

/**

 * This function simulate a 64-bit index of LITTLE ENDIAN

 * in BIG ENDIAN machine.

 */

#ifdef ONLY64

inline static int idxof(int i) {

    return i ^ 1;

}

#else

inline static int idxof(int i) {

    return i;

}

#endif

#if (!defined(HAVE_ALTIVEC)) && (!defined(HAVE_SSE2))

/**

 * This function fills the user-specified array with pseudorandom

 * integers.

 *

 * @param sfmt SFMT internal state

 * @param array an 128-bit array to be filled by pseudorandom numbers.

 * @param size number of 128-bit pseudorandom numbers to be generated.

 */

inline static void gen_rand_array(sfmt_t * sfmt, w128_t *array, int size) {

    int i, j;

    w128_t *r1, *r2;

    r1 = &sfmt->state[SFMT_N - 2];

    r2 = &sfmt->state[SFMT_N - 1];

    for (i = 0; i < SFMT_N - SFMT_POS1; i++) {

  do_recursion(&array[i], &sfmt->state[i], &sfmt->state[i + SFMT_POS1], r1, r2);

  r1 = r2;

  r2 = &array[i];

    }

    for (; i < SFMT_N; i++) {

  do_recursion(&array[i], &sfmt->state[i],

         &array[i + SFMT_POS1 - SFMT_N], r1, r2);

  r1 = r2;

  r2 = &array[i];

    }

    for (; i < size - SFMT_N; i++) {

  do_recursion(&array[i], &array[i - SFMT_N],

         &array[i + SFMT_POS1 - SFMT_N], r1, r2);

  r1 = r2;

  r2 = &array[i];

    }

    for (j = 0; j < 2 * SFMT_N - size; j++) {

  sfmt->state[j] = array[j + size - SFMT_N];

    }

    for (; i < size; i++, j++) {

  do_recursion(&array[i], &array[i - SFMT_N],

         &array[i + SFMT_POS1 - SFMT_N], r1, r2);

  r1 = r2;

  r2 = &array[i];

  sfmt->state[j] = array[i];

    }

}

#endif

#if defined(BIG_ENDIAN64) && !defined(ONLY64) && !defined(HAVE_ALTIVEC)

inline static void swap(w128_t *array, int size) {

    int i;

    uint32_t x, y;

    for (i = 0; i < size; i++) {

  x = array[i].u[0];

  y = array[i].u[2];

  array[i].u[0] = array[i].u[1];

  array[i].u[2] = array[i].u[3];

  array[i].u[1] = x;

  array[i].u[3] = y;

    }

}

#endif

/**

 * This function represents a function used in the initialization

 * by init_by_array

 * @param x 32-bit integer

 * @return 32-bit integer

 */

static uint32_t func1(uint32_t x) {

    return (x ^ (x >> 27)) * (uint32_t)1664525UL;

}

/**

 * This function represents a function used in the initialization

 * by init_by_array

 * @param x 32-bit integer

 * @return 32-bit integer

 */

static uint32_t func2(uint32_t x) {

    return (x ^ (x >> 27)) * (uint32_t)1566083941UL;

}

/**

 * This function certificate the period of 2^{MEXP}

 * @param sfmt SFMT internal state

 */

static void period_certification(sfmt_t * sfmt) {

    int inner = 0;

    int i, j;

    uint32_t work;

    uint32_t *psfmt32 = &sfmt->state[0].u[0];

    const uint32_t parity[4] = {SFMT_PARITY1, SFMT_PARITY2,

        SFMT_PARITY3, SFMT_PARITY4};

    for (i = 0; i < 4; 
i++600k
)

  inner ^= psfmt32[idxof(i)] & parity[i];

    for (i = 16; i > 0; 
i >>= 1750k
)

  inner ^= inner >> i;

    inner &= 1;

    /* check OK */

    if (inner == 1) {

  return;

    }

    /* check NG, and modification */

    for (i = 0; i < 4; 
i++0
) {

  work = 1;

  for (j = 0; j < 32; 
j++0
) {

      if ((work & parity[i]) != 0) {

    psfmt32[idxof(i)] ^= work;

    return;

      }

      work = work << 1;

  }

    }

}

/*----------------

  PUBLIC FUNCTIONS

  ----------------*/

#define UNUSED_VARIABLE(x) (void)(x)

/**

 * This function returns the identification string.

 * The string shows the word size, the Mersenne exponent,

 * and all parameters of this generator.

 * @param sfmt SFMT internal state

 */

const char *sfmt_get_idstring(sfmt_t * sfmt) {

    UNUSED_VARIABLE(sfmt);

    return SFMT_IDSTR;

}

/**

 * This function returns the minimum size of array used for \b

 * fill_array32() function.

 * @param sfmt SFMT internal state

 * @return minimum size of array used for fill_array32() function.

 */

int sfmt_get_min_array_size32(sfmt_t * sfmt) {

    UNUSED_VARIABLE(sfmt);

    return SFMT_N32;

}

/**

 * This function returns the minimum size of array used for \b

 * fill_array64() function.

 * @param sfmt SFMT internal state

 * @return minimum size of array used for fill_array64() function.

 */

int sfmt_get_min_array_size64(sfmt_t * sfmt) {

    UNUSED_VARIABLE(sfmt);

    return SFMT_N64;

}

#if !defined(HAVE_SSE2) && !defined(HAVE_ALTIVEC)

/**

 * This function fills the internal state array with pseudorandom

 * integers.

 * @param sfmt SFMT internal state

 */

void sfmt_gen_rand_all(sfmt_t * sfmt) {

    int i;

    w128_t *r1, *r2;

    r1 = &sfmt->state[SFMT_N - 2];

    r2 = &sfmt->state[SFMT_N - 1];

    for (i = 0; i < SFMT_N - SFMT_POS1; i++) {

  do_recursion(&sfmt->state[i], &sfmt->state[i],

         &sfmt->state[i + SFMT_POS1], r1, r2);

  r1 = r2;

  r2 = &sfmt->state[i];

    }

    for (; i < SFMT_N; i++) {

  do_recursion(&sfmt->state[i], &sfmt->state[i],

         &sfmt->state[i + SFMT_POS1 - SFMT_N], r1, r2);

  r1 = r2;

  r2 = &sfmt->state[i];

    }

}

#endif

#ifndef ONLY64

/**

 * This function generates pseudorandom 32-bit integers in the

 * specified array[] by one call. The number of pseudorandom integers

 * is specified by the argument size, which must be at least 624 and a

 * multiple of four.  The generation by this function is much faster

 * than the following gen_rand function.

 *

 * For initialization, init_gen_rand or init_by_array must be called

 * before the first call of this function. This function can not be

 * used after calling gen_rand function, without initialization.

 *

 * @param sfmt SFMT internal state

 * @param array an array where pseudorandom 32-bit integers are filled

 * by this function.  The pointer to the array must be \b "aligned"

 * (namely, must be a multiple of 16) in the SIMD version, since it

 * refers to the address of a 128-bit integer.  In the standard C

 * version, the pointer is arbitrary.

 *

 * @param size the number of 32-bit pseudorandom integers to be

 * generated.  size must be a multiple of 4, and greater than or equal

 * to (MEXP / 128 + 1) * 4.

 *

 * @note \b memalign or \b posix_memalign is available to get aligned

 * memory. Mac OSX doesn't have these functions, but \b malloc of OSX

 * returns the pointer to the aligned memory block.

 */

void sfmt_fill_array32(sfmt_t * sfmt, uint32_t *array, int size) {

    assert(sfmt->idx == SFMT_N32);

    assert(size % 4 == 0);

    assert(size >= SFMT_N32);

    gen_rand_array(sfmt, (w128_t *)array, size / 4);

    sfmt->idx = SFMT_N32;

}

#endif

/**

 * This function generates pseudorandom 64-bit integers in the

 * specified array[] by one call. The number of pseudorandom integers

 * is specified by the argument size, which must be at least 312 and a

 * multiple of two.  The generation by this function is much faster

 * than the following gen_rand function.

 *

 * @param sfmt SFMT internal state

 * For initialization, init_gen_rand or init_by_array must be called

 * before the first call of this function. This function can not be

 * used after calling gen_rand function, without initialization.

 *

 * @param array an array where pseudorandom 64-bit integers are filled

 * by this function.  The pointer to the array must be "aligned"

 * (namely, must be a multiple of 16) in the SIMD version, since it

 * refers to the address of a 128-bit integer.  In the standard C

 * version, the pointer is arbitrary.

 *

 * @param size the number of 64-bit pseudorandom integers to be

 * generated.  size must be a multiple of 2, and greater than or equal

 * to (MEXP / 128 + 1) * 2

 *

 * @note \b memalign or \b posix_memalign is available to get aligned

 * memory. Mac OSX doesn't have these functions, but \b malloc of OSX

 * returns the pointer to the aligned memory block.

 */

void sfmt_fill_array64(sfmt_t * sfmt, uint64_t *array, int size) {

    assert(sfmt->idx == SFMT_N32);

    assert(size % 2 == 0);

    assert(size >= SFMT_N64);

    gen_rand_array(sfmt, (w128_t *)array, size / 2);

    sfmt->idx = SFMT_N32;

#if defined(BIG_ENDIAN64) && !defined(ONLY64)

    swap((w128_t *)array, size /2);

#endif

}

/**

 * This function randomly shuffle the given array

 *

 * @param sfmt SFMT internal state

 * @param array the array that is going to be shuffled

 * @param size the size of the array

 * @param rsize the size of each record in the array

 */

#if !defined(__OpenBSD__) && !defined(__FreeBSD__) && !defined(__NetBSD__)

#include <alloca.h>

#endif

void sfmt_genrand_shuffle(sfmt_t * sfmt, void *array, int size, int rsize) {

  int i, j;

  char *t = (char *)alloca(rsize);

  char *ptr = (char *)array;

  char *ptri = ptr + (size - 1) * rsize;

  for (i = size - 1; i >= 0; 
i--600k
) {

    j = sfmt_genrand_uint32(sfmt) % (i + 1);

    if (i != j)

    {

      char *ptrj = ptr + j * rsize;

      memcpy(t, ptri, rsize);

      memcpy(ptri, ptrj, rsize);

      memcpy(ptrj, t, rsize);

    }

    ptri -= rsize;

  }

}

/**

 * This function initializes the internal state array with a 32-bit

 * integer seed.

 *

 * @param sfmt SFMT internal state

 * @param seed a 32-bit integer used as the seed.

 */

void sfmt_init_gen_rand(sfmt_t * sfmt, uint32_t seed) {

    int i;

    uint32_t *psfmt32 = &sfmt->state[0].u[0];

    psfmt32[idxof(0)] = seed;

    for (i = 1; i < SFMT_N32; 
i++93.4M
) {

  psfmt32[idxof(i)] = 1812433253UL * (psfmt32[idxof(i - 1)]

              ^ (psfmt32[idxof(i - 1)] >> 30))

      + i;

    }

    sfmt->idx = SFMT_N32;

    period_certification(sfmt);

}

/**

 * This function initializes the internal state array,

 * with an array of 32-bit integers used as the seeds

 * @param sfmt SFMT internal state

 * @param init_key the array of 32-bit integers, used as a seed.

 * @param key_length the length of init_key.

 */

void sfmt_init_by_array(sfmt_t * sfmt, uint32_t *init_key, int key_length) {

    int i, j, count;

    uint32_t r;

    int lag;

    int mid;

    int size = SFMT_N * 4;

    uint32_t *psfmt32 = &sfmt->state[0].u[0];

    if (size >= 623) {

  lag = 11;

    } else if (size >= 68) {

  lag = 7;

    } else if (size >= 39) {

  lag = 5;

    } else {

  lag = 3;

    }

    mid = (size - lag) / 2;

    memset(sfmt, 0x8b, sizeof(sfmt_t));

    if (key_length + 1 > SFMT_N32) {

  count = key_length + 1;

    } else {

  count = SFMT_N32;

    }

    r = func1(psfmt32[idxof(0)] ^ psfmt32[idxof(mid)]

        ^ psfmt32[idxof(SFMT_N32 - 1)]);

    psfmt32[idxof(mid)] += r;

    r += key_length;

    psfmt32[idxof(mid + lag)] += r;

    psfmt32[idxof(0)] = r;

    count--;

    for (i = 1, j = 0; (j < count) && (j < key_length); j++) {

  r = func1(psfmt32[idxof(i)] ^ psfmt32[idxof((i + mid) % SFMT_N32)]

      ^ psfmt32[idxof((i + SFMT_N32 - 1) % SFMT_N32)]);

  psfmt32[idxof((i + mid) % SFMT_N32)] += r;

  r += init_key[j] + i;

  psfmt32[idxof((i + mid + lag) % SFMT_N32)] += r;

  psfmt32[idxof(i)] = r;

  i = (i + 1) % SFMT_N32;

    }

    for (; j < count; j++) {

  r = func1(psfmt32[idxof(i)] ^ psfmt32[idxof((i + mid) % SFMT_N32)]

      ^ psfmt32[idxof((i + SFMT_N32 - 1) % SFMT_N32)]);

  psfmt32[idxof((i + mid) % SFMT_N32)] += r;

  r += i;

  psfmt32[idxof((i + mid + lag) % SFMT_N32)] += r;

  psfmt32[idxof(i)] = r;

  i = (i + 1) % SFMT_N32;

    }

    for (j = 0; j < SFMT_N32; j++) {

  r = func2(psfmt32[idxof(i)] + psfmt32[idxof((i + mid) % SFMT_N32)]

      + psfmt32[idxof((i + SFMT_N32 - 1) % SFMT_N32)]);

  psfmt32[idxof((i + mid) % SFMT_N32)] ^= r;

  r -= i;

  psfmt32[idxof((i + mid + lag) % SFMT_N32)] ^= r;

  psfmt32[idxof(i)] = r;

  i = (i + 1) % SFMT_N32;

    }

    sfmt->idx = SFMT_N32;

    period_certification(sfmt);

}

#if defined(__cplusplus)

}

#endif