ermyth/src/random.C

/**
 * random.C: SIMD oriented Fast Mersenne Twister(SFMT)
 *
 * Copyright © 2007 Pippijn van Steenhoven / The Ermyth Team
 * Rights to this code are as documented in COPYING.
 *
 *
 * Portions of this file were derived from sources bearing the following license:
 *
 * Copyright © 2006, 2007 Mutsuo Saito, Makoto Matsumoto and Hiroshima
 * University. All rights reserved.
 *
 * @author Mutsuo Saito (Hiroshima University)
 * @author Makoto Matsumoto (Hiroshima University)
 *
 * The new BSD License is applied to this software.
 */

static char const rcsid[] = "$Id: random.C,v 1.3 2007-09-16 18:54:45 pippijn Exp $";

#include <string.h>
#include <assert.h>

#include <common/random.h>

/*-----------------
  BASIC DEFINITIONS
  -----------------*/
/** SFMT generator has an internal state array of 128-bit integers,
 * and N is its size. */
#define N (216091 / 128 + 1)
/** N32 is the size of internal state array when regarded as an array
 * of 32-bit integers.*/
#define N32 (N * 4)
/** N64 is the size of internal state array when regarded as an array
 * of 64-bit integers.*/
#define N64 (N * 2)

/*----------------------
  the parameters of SFMT
  following definitions are in paramsXXXX.h file.
  ----------------------*/
// the pick up position of the array.
#define POS1    627
// the parameter of shift left as four 32-bit registers.
#define SL1     11
// the parameter of shift left as one 128-bit register. 
// The 128-bit integer is shifted by (SL2 * 8) bits. 
#define SL2     3
// the parameter of shift right as four 32-bit registers.
#define SR1     10
// the parameter of shift right as one 128-bit register. 
// The 128-bit integer is shifted by (SL2 * 8) bits. 
#define SR2     1
// A bitmask, used in the recursion.  These parameters are introduced
// to break symmetry of SIMD.
#define MSK1    0xbff7bff7U
#define MSK2    0xbfffffffU
#define MSK3    0xbffffa7fU
#define MSK4    0xffddfbfbU
// These definitions are part of a 128-bit period certification vector.
#define PARITY1 0xf8000001U
#define PARITY2 0x89e80709U
#define PARITY3 0x3bd2b64bU
#define PARITY4 0x0c64b1e4U

/* PARAMETERS FOR ALTIVEC */
#if defined(__APPLE__)          /* For OSX */
#define ALTI_SL1                (vector unsigned int)(SL1, SL1, SL1, SL1)
#define ALTI_SR1                (vector unsigned int)(SR1, SR1, SR1, SR1)
#define ALTI_MSK                (vector unsigned int)(MSK1, MSK2, MSK3, MSK4)
#define ALTI_MSK64              (vector unsigned int)(MSK2, MSK1, MSK4, MSK3)
#define ALTI_SL2_PERM           (vector unsigned char)(3,21,21,21,7,0,1,2,11,4,5,6,15,8,9,10)
#define ALTI_SL2_PERM64         (vector unsigned char)(3,4,5,6,7,29,29,29,11,12,13,14,15,0,1,2)
#define ALTI_SR2_PERM           (vector unsigned char)(7,0,1,2,11,4,5,6,15,8,9,10,17,12,13,14)
#define ALTI_SR2_PERM64         (vector unsigned char)(15,0,1,2,3,4,5,6,17,8,9,10,11,12,13,14)
#else // !__APPLE__
#define ALTI_SL1                {SL1, SL1, SL1, SL1}
#define ALTI_SR1                {SR1, SR1, SR1, SR1}
#define ALTI_MSK                {MSK1, MSK2, MSK3, MSK4}
#define ALTI_MSK64              {MSK2, MSK1, MSK4, MSK3}
#define ALTI_SL2_PERM           { 3,21,21,21, 7, 0, 1, 2,11, 4, 5, 6,15, 8, 9,10}
#define ALTI_SL2_PERM64         { 3, 4, 5, 6, 7,29,29,29,11,12,13,14,15, 0, 1, 2}
#define ALTI_SR2_PERM           { 7, 0, 1, 2,11, 4, 5, 6,15, 8, 9,10,17,12,13,14}
#define ALTI_SR2_PERM64         {15, 0, 1, 2, 3, 4, 5, 6,17, 8, 9,10,11,12,13,14}
#endif // __APPLE__
#define IDSTR   "SFMT-216091:627-11-3-10-1:bff7bff7-bfffffff-bffffa7f-ffddfbfb"

#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

/*--------------------------------------
  FILE GLOBAL VARIABLES
  internal state, index counter and flag 
  --------------------------------------*/
/** the 128-bit internal state array */
static w128_t sfmt[N];
/** the 32bit integer pointer to the 128-bit internal state array */
static uint32_t *psfmt32 = &sfmt[0].u[0];
#if !defined(BIG_ENDIAN64) || defined(ONLY64)
/** the 64bit integer pointer to the 128-bit internal state array */
static uint64_t *psfmt64 = reinterpret_cast<uint64_t *> (&sfmt[0].u[0]);
#endif
/** index counter to the 32-bit internal state array */
static int idx;
/** a flag: it is 0 if and only if the internal state is not yet
 * initialized. */
static int initialized = 0;
/** a parity check vector which certificate the period of 2^{MEXP} */
static uint32_t parity[4] = { PARITY1, PARITY2, PARITY3, PARITY4 };

/*----------------
  STATIC FUNCTIONS
  ----------------*/
inline static int idxof (int i);
inline static void rshift128 (w128_t *out, w128_t const *in, int shift);
inline static void lshift128 (w128_t *out, w128_t const *in, int shift);
inline static void gen_rand_all (void);
inline static void gen_rand_array (w128_t *array, int size);
inline static uint32_t func1 (uint32_t x);
inline static uint32_t func2 (uint32_t x);
inline static void period_certification (void);
#if defined(BIG_ENDIAN64) && !defined(ONLY64)
inline static void swap (w128_t *array, int size);
#endif

#if defined(HAVE_ALTIVEC)
inline static vector unsigned int
vec_recursion (vector unsigned int a, vector unsigned int b, vector unsigned int c, vector unsigned int d) ALWAYSINLINE;

/**
 * This function represents the recursion formula in AltiVec and BIG ENDIAN.
 * @param a a 128-bit part of the interal state array
 * @param b a 128-bit part of the interal state array
 * @param c a 128-bit part of the interal state array
 * @param d a 128-bit part of the interal state array
 * @return output
 */
inline static vector unsigned int vec_recursion (vector unsigned int a, vector unsigned int b, vector unsigned int c, vector unsigned int d)
{
  const vector unsigned int sl1 = ALTI_SL1;
  const vector unsigned int sr1 = ALTI_SR1;
#ifdef ONLY64
  const vector unsigned int mask = ALTI_MSK64;
  const vector unsigned char perm_sl = ALTI_SL2_PERM64;
  const vector unsigned char perm_sr = ALTI_SR2_PERM64;
#else
  const vector unsigned int mask = ALTI_MSK;
  const vector unsigned char perm_sl = ALTI_SL2_PERM;
  const vector unsigned char perm_sr = ALTI_SR2_PERM;
#endif
  vector unsigned int v, w, x, y, z;
  x = vec_perm (a, (vector unsigned int) perm_sl, perm_sl);
  v = a;
  y = vec_sr (b, sr1);
  z = vec_perm (c, (vector unsigned int) perm_sr, perm_sr);
  w = vec_sl (d, sl1);
  z = vec_xor (z, w);
  y = vec_and (y, mask);
  v = vec_xor (v, x);
  z = vec_xor (z, y);
  z = vec_xor (z, v);
  return z;
}

/**
 * This function fills the internal state array with pseudorandom
 * integers.
 */
inline static void
gen_rand_all (void)
{
  int i;
  vector unsigned int r, r1, r2;

  r1 = sfmt[N - 2].s;
  r2 = sfmt[N - 1].s;
  for (i = 0; i < N - POS1; i++)
    {
      r = vec_recursion (sfmt[i].s, sfmt[i + POS1].s, r1, r2);
      sfmt[i].s = r;
      r1 = r2;
      r2 = r;
    }
  for (; i < N; i++)
    {
      r = vec_recursion (sfmt[i].s, sfmt[i + POS1 - N].s, r1, r2);
      sfmt[i].s = r;
      r1 = r2;
      r2 = r;
    }
}

/**
 * This function fills the user-specified array with pseudorandom
 * integers.
 *
 * @param array an 128-bit array to be filled by pseudorandom numbers.  
 * @param size number of 128-bit pesudorandom numbers to be generated.
 */
inline static void
gen_rand_array (w128_t *array, int size)
{
  int i, j;
  vector unsigned int r, r1, r2;

  r1 = sfmt[N - 2].s;
  r2 = sfmt[N - 1].s;
  for (i = 0; i < N - POS1; i++)
    {
      r = vec_recursion (sfmt[i].s, sfmt[i + POS1].s, r1, r2);
      array[i].s = r;
      r1 = r2;
      r2 = r;
    }
  for (; i < N; i++)
    {
      r = vec_recursion (sfmt[i].s, array[i + POS1 - N].s, r1, r2);
      array[i].s = r;
      r1 = r2;
      r2 = r;
    }
  /* main loop */
  for (; i < size - N; i++)
    {
      r = vec_recursion (array[i - N].s, array[i + POS1 - N].s, r1, r2);
      array[i].s = r;
      r1 = r2;
      r2 = r;
    }
  for (j = 0; j < 2 * N - size; j++)
    {
      sfmt[j].s = array[j + size - N].s;
    }
  for (; i < size; i++)
    {
      r = vec_recursion (array[i - N].s, array[i + POS1 - N].s, r1, r2);
      array[i].s = r;
      sfmt[j++].s = r;
      r1 = r2;
      r2 = r;
    }
}

#ifndef ONLY64
#if defined(__APPLE__)
#define ALTI_SWAP (vector unsigned char) \
        (4, 5, 6, 7, 0, 1, 2, 3, 12, 13, 14, 15, 8, 9, 10, 11)
#else
#define ALTI_SWAP {4, 5, 6, 7, 0, 1, 2, 3, 12, 13, 14, 15, 8, 9, 10, 11}
#endif
/**
 * This function swaps high and low 32-bit of 64-bit integers in user
 * specified array.
 *
 * @param array an 128-bit array to be swaped.
 * @param size size of 128-bit array.
 */
inline static void
swap (w128_t *array, int size)
{
  int i;
  const vector unsigned char perm = ALTI_SWAP;

  for (i = 0; i < size; i++)
    {
      array[i].s = vec_perm (array[i].s, (vector unsigned int) perm, perm);
    }
}
#endif
#elif defined(HAVE_SSE2)
inline static __m128i
mm_recursion (__m128i *a, __m128i *b, __m128i c, __m128i d, __m128i mask);

/**
 * This function represents the recursion formula.
 * @param a a 128-bit part of the interal state array
 * @param b a 128-bit part of the interal state array
 * @param c a 128-bit part of the interal state array
 * @param d a 128-bit part of the interal state array
 * @param mask 128-bit mask
 * @return output
 */
inline static __m128i mm_recursion (__m128i *a, __m128i *b, __m128i c, __m128i d, __m128i mask)
{
  __m128i v, x, y, z;
  
  x = _mm_load_si128 (a);
  y = _mm_srli_epi32 (*b, SR1);
  z = _mm_srli_si128 (c, SR2);
  v = _mm_slli_epi32 (d, SL1);
  z = _mm_xor_si128 (z, x);
  z = _mm_xor_si128 (z, v);
  x = _mm_slli_si128 (x, SL2);
  y = _mm_and_si128 (y, mask);
  z = _mm_xor_si128 (z, x);
  z = _mm_xor_si128 (z, y);
  return z;
}

/**
 * This function fills the internal state array with pseudorandom
 * integers.
 */
inline static void
gen_rand_all (void)
{
  int i;
  __m128i r, r1, r2, mask;
  mask = _mm_set_epi32 (MSK4, MSK3, MSK2, MSK1);

  r1 = _mm_load_si128 (&sfmt[N - 2].si);
  r2 = _mm_load_si128 (&sfmt[N - 1].si);
  for (i = 0; i < N - POS1; i++)
    {
      r = mm_recursion (&sfmt[i].si, &sfmt[i + POS1].si, r1, r2, mask);
      _mm_store_si128 (&sfmt[i].si, r);
      r1 = r2;
      r2 = r;
    }
  for (; i < N; i++)
    {
      r = mm_recursion (&sfmt[i].si, &sfmt[i + POS1 - N].si, r1, r2, mask);
      _mm_store_si128 (&sfmt[i].si, r);
      r1 = r2;
      r2 = r;
    }
}

/**
 * This function fills the user-specified array with pseudorandom
 * integers.
 *
 * @param array an 128-bit array to be filled by pseudorandom numbers.  
 * @param size number of 128-bit pesudorandom numbers to be generated.
 */
inline static void
gen_rand_array (w128_t *array, int size)
{
  int i, j;
  __m128i r, r1, r2, mask;
  mask = _mm_set_epi32 (MSK4, MSK3, MSK2, MSK1);

  r1 = _mm_load_si128 (&sfmt[N - 2].si);
  r2 = _mm_load_si128 (&sfmt[N - 1].si);
  for (i = 0; i < N - POS1; i++)
    {
      r = mm_recursion (&sfmt[i].si, &sfmt[i + POS1].si, r1, r2, mask);
      _mm_store_si128 (&array[i].si, r);
      r1 = r2;
      r2 = r;
    }
  for (; i < N; i++)
    {
      r = mm_recursion (&sfmt[i].si, &array[i + POS1 - N].si, r1, r2, mask);
      _mm_store_si128 (&array[i].si, r);
      r1 = r2;
      r2 = r;
    }
  /* main loop */
  for (; i < size - N; i++)
    {
      r = mm_recursion (&array[i - N].si, &array[i + POS1 - N].si, r1, r2, mask);
      _mm_store_si128 (&array[i].si, r);
      r1 = r2;
      r2 = r;
    }
  for (j = 0; j < 2 * N - size; j++)
    {
      r = _mm_load_si128 (&array[j + size - N].si);
      _mm_store_si128 (&sfmt[j].si, r);
    }
  for (; i < size; i++)
    {
      r = mm_recursion (&array[i - N].si, &array[i + POS1 - N].si, r1, r2, mask);
      _mm_store_si128 (&array[i].si, r);
      _mm_store_si128 (&sfmt[j++].si, r);
      r1 = r2;
      r2 = r;
    }
}
#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
/**
 * This function simulates SIMD 128-bit right shift by the standard C.
 * The 128-bit integer given in in is shifted by (shift * 8) bits.
 * This function simulates the LITTLE ENDIAN SIMD.
 * @param out the output of this function
 * @param in the 128-bit data to be shifted
 * @param shift the shift value
 */
#ifdef ONLY64
inline static void
rshift128 (w128_t *out, w128_t const *in, int shift)
{
  uint64_t th, tl, oh, ol;

  th = ((uint64_t) in->u[2] << 32) | ((uint64_t) in->u[3]);
  tl = ((uint64_t) in->u[0] << 32) | ((uint64_t) in->u[1]);

  oh = th >> (shift * 8);
  ol = tl >> (shift * 8);
  ol |= th << (64 - shift * 8);
  out->u[0] = (uint32_t) (ol >> 32);
  out->u[1] = (uint32_t) ol;
  out->u[2] = (uint32_t) (oh >> 32);
  out->u[3] = (uint32_t) oh;
}
#else
inline static void
rshift128 (w128_t *out, w128_t const *in, int shift)
{
  uint64_t th, tl, oh, ol;

  th = ((uint64_t) in->u[3] << 32) | ((uint64_t) in->u[2]);
  tl = ((uint64_t) in->u[1] << 32) | ((uint64_t) in->u[0]);

  oh = th >> (shift * 8);
  ol = tl >> (shift * 8);
  ol |= th << (64 - shift * 8);
  out->u[1] = (uint32_t) (ol >> 32);
  out->u[0] = (uint32_t) ol;
  out->u[3] = (uint32_t) (oh >> 32);
  out->u[2] = (uint32_t) oh;
}
#endif
/**
 * This function simulates SIMD 128-bit left shift by the standard C.
 * The 128-bit integer given in in is shifted by (shift * 8) bits.
 * This function simulates the LITTLE ENDIAN SIMD.
 * @param out the output of this function
 * @param in the 128-bit data to be shifted
 * @param shift the shift value
 */
#ifdef ONLY64
inline static void
lshift128 (w128_t *out, w128_t const *in, int shift)
{
  uint64_t th, tl, oh, ol;

  th = ((uint64_t) in->u[2] << 32) | ((uint64_t) in->u[3]);
  tl = ((uint64_t) in->u[0] << 32) | ((uint64_t) in->u[1]);

  oh = th << (shift * 8);
  ol = tl << (shift * 8);
  oh |= tl >> (64 - shift * 8);
  out->u[0] = (uint32_t) (ol >> 32);
  out->u[1] = (uint32_t) ol;
  out->u[2] = (uint32_t) (oh >> 32);
  out->u[3] = (uint32_t) oh;
}
#else
inline static void
lshift128 (w128_t *out, w128_t const *in, int shift)
{
  uint64_t th, tl, oh, ol;

  th = ((uint64_t) in->u[3] << 32) | ((uint64_t) in->u[2]);
  tl = ((uint64_t) in->u[1] << 32) | ((uint64_t) in->u[0]);

  oh = th << (shift * 8);
  ol = tl << (shift * 8);
  oh |= tl >> (64 - shift * 8);
  out->u[1] = (uint32_t) (ol >> 32);
  out->u[0] = (uint32_t) ol;
  out->u[3] = (uint32_t) (oh >> 32);
  out->u[2] = (uint32_t) oh;
}
#endif

/**
 * This function represents the recursion formula.
 * @param r output
 * @param a a 128-bit part of the internal state array
 * @param b a 128-bit part of the internal state array
 * @param c a 128-bit part of the internal state array
 * @param d a 128-bit part of the internal state array
 */
#ifdef ONLY64
inline static void
do_recursion (w128_t *r, w128_t *a, w128_t *b, w128_t *c, w128_t *d)
{
  w128_t x;
  w128_t y;

  lshift128 (&x, a, SL2);
  rshift128 (&y, c, SR2);
  r->u[0] = a->u[0] ^ x.u[0] ^ ((b->u[0] >> SR1) & MSK2) ^ y.u[0] ^ (d->u[0] << SL1);
  r->u[1] = a->u[1] ^ x.u[1] ^ ((b->u[1] >> SR1) & MSK1) ^ y.u[1] ^ (d->u[1] << SL1);
  r->u[2] = a->u[2] ^ x.u[2] ^ ((b->u[2] >> SR1) & MSK4) ^ y.u[2] ^ (d->u[2] << SL1);
  r->u[3] = a->u[3] ^ x.u[3] ^ ((b->u[3] >> SR1) & MSK3) ^ y.u[3] ^ (d->u[3] << SL1);
}
#else
inline static void
do_recursion (w128_t *r, w128_t *a, w128_t *b, w128_t *c, w128_t *d)
{
  w128_t x;
  w128_t y;

  lshift128 (&x, a, SL2);
  rshift128 (&y, c, SR2);
  r->u[0] = a->u[0] ^ x.u[0] ^ ((b->u[0] >> SR1) & MSK1) ^ y.u[0] ^ (d->u[0] << SL1);
  r->u[1] = a->u[1] ^ x.u[1] ^ ((b->u[1] >> SR1) & MSK2) ^ y.u[1] ^ (d->u[1] << SL1);
  r->u[2] = a->u[2] ^ x.u[2] ^ ((b->u[2] >> SR1) & MSK3) ^ y.u[2] ^ (d->u[2] << SL1);
  r->u[3] = a->u[3] ^ x.u[3] ^ ((b->u[3] >> SR1) & MSK4) ^ y.u[3] ^ (d->u[3] << SL1);
}
#endif

#if (!defined(HAVE_ALTIVEC)) && (!defined(HAVE_SSE2))
/**
 * This function fills the internal state array with pseudorandom
 * integers.
 */
inline static void
gen_rand_all (void)
{
  int i;
  w128_t *r1, *r2;

  r1 = &sfmt[N - 2];
  r2 = &sfmt[N - 1];
  for (i = 0; i < N - POS1; i++)
    {
      do_recursion (&sfmt[i], &sfmt[i], &sfmt[i + POS1], r1, r2);
      r1 = r2;
      r2 = &sfmt[i];
    }
  for (; i < N; i++)
    {
      do_recursion (&sfmt[i], &sfmt[i], &sfmt[i + POS1 - N], r1, r2);
      r1 = r2;
      r2 = &sfmt[i];
    }
}

/**
 * This function fills the user-specified array with pseudorandom
 * integers.
 *
 * @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 (w128_t *array, int size)
{
  int i, j;
  w128_t *r1, *r2;

  r1 = &sfmt[N - 2];
  r2 = &sfmt[N - 1];
  for (i = 0; i < N - POS1; i++)
    {
      do_recursion (&array[i], &sfmt[i], &sfmt[i + POS1], r1, r2);
      r1 = r2;
      r2 = &array[i];
    }
  for (; i < N; i++)
    {
      do_recursion (&array[i], &sfmt[i], &array[i + POS1 - N], r1, r2);
      r1 = r2;
      r2 = &array[i];
    }
  for (; i < size - N; i++)
    {
      do_recursion (&array[i], &array[i - N], &array[i + POS1 - N], r1, r2);
      r1 = r2;
      r2 = &array[i];
    }
  for (j = 0; j < 2 * N - size; j++)
    {
      sfmt[j] = array[j + size - N];
    }
  for (; i < size; i++, j++)
    {
      do_recursion (&array[i], &array[i - N], &array[i + POS1 - N], r1, r2);
      r1 = r2;
      r2 = &array[i];
      sfmt[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
 */
inline 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
 */
inline static uint32_t
func2 (uint32_t x)
{
  return (x ^ (x >> 27)) * (uint32_t) 1566083941UL;
}

/**
 * This function certificate the period of 2^{MEXP}
 */
static void
period_certification (void)
{
  int inner = 0;
  int i, j;
  uint32_t work;

  for (i = 0; i < 4; i++)
    inner ^= psfmt32[idxof (i)] & parity[i];
  for (i = 16; i > 0; i >>= 1)
    inner ^= inner >> i;
  inner &= 1;
  /* check OK */
  if (inner == 1)
    {
      return;
    }
  /* check NG, and modification */
  for (i = 0; i < 4; i++)
    {
      work = 1;
      for (j = 0; j < 32; j++)
        {
          if ((work & parity[i]) != 0)
            {
              psfmt32[idxof (i)] ^= work;
              return;
            }
          work = work << 1;
        }
    }
}

/*----------------
  PUBLIC FUNCTIONS
  ----------------*/
/**
 * This function returns the identification string.
 * The string shows the word size, the Mersenne exponent,
 * and all parameters of this generator.
 */
char const * const
get_idstring (void)
{
  return IDSTR;
}

/**
 * This function returns the minimum size of array used for \b
 * fill_array32() function.
 * @return minimum size of array used for fill_array32() function.
 */
int
get_min_array_size32 (void)
{
  return N32;
}

/**
 * This function returns the minimum size of array used for \b
 * fill_array64() function.
 * @return minimum size of array used for fill_array64() function.
 */
int
get_min_array_size64 (void)
{
  return N64;
}

#ifndef ONLY64
/**
 * This function generates and returns 32-bit pseudorandom number.
 * init_gen_rand or init_by_array must be called before this function.
 * @return 32-bit pseudorandom number
 */
uint32_t
gen_rand32 (void)
{
  uint32_t r;

  assert (initialized);
  if (idx >= N32)
    {
      gen_rand_all ();
      idx = 0;
    }
  r = psfmt32[idx++];
  return r;
}
#endif
/**
 * This function generates and returns 64-bit pseudorandom number.
 * init_gen_rand or init_by_array must be called before this function.
 * The function gen_rand64 should not be called after gen_rand32,
 * unless an initialization is again executed. 
 * @return 64-bit pseudorandom number
 */
uint64_t
gen_rand64 (void)
{
#if defined(BIG_ENDIAN64) && !defined(ONLY64)
  uint32_t r1, r2;
#else
  uint64_t r;
#endif

  assert (initialized);
  assert (idx % 2 == 0);

  if (idx >= N32)
    {
      gen_rand_all ();
      idx = 0;
    }
#if defined(BIG_ENDIAN64) && !defined(ONLY64)
  r1 = psfmt32[idx];
  r2 = psfmt32[idx + 1];
  idx += 2;
  return ((uint64_t) r2 << 32) | r1;
#else
  r = psfmt64[idx / 2];
  idx += 2;
  return r;
#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 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
fill_array32 (uint32_t * array, int size)
{
  assert (initialized);
  assert (idx == N32);
  assert (size % 4 == 0);
  assert (size >= N32);

  gen_rand_array (reinterpret_cast<w128_t *> (array), size / 4);
  idx = 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.
 *
 * 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
fill_array64 (uint64_t * array, int size)
{
  assert (initialized);
  assert (idx == N32);
  assert (size % 2 == 0);
  assert (size >= N64);

  gen_rand_array (reinterpret_cast<w128_t *> (array), size / 2);
  idx = N32;

#if defined(BIG_ENDIAN64) && !defined(ONLY64)
  swap (reinterpret_cast<w128_t *> (array), size / 2);
#endif
}

/**
 * This function initializes the internal state array with a 32-bit
 * integer seed.
 *
 * @param seed a 32-bit integer used as the seed.
 */
void
init_gen_rand (uint32_t seed)
{
  int i;

  psfmt32[idxof (0)] = seed;
  for (i = 1; i < N32; i++)
    {
      psfmt32[idxof (i)] = 1812433253UL * (psfmt32[idxof (i - 1)] ^ (psfmt32[idxof (i - 1)] >> 30)) + i;
    }
  idx = N32;
  period_certification ();
  initialized = 1;
}

/**
 * This function initializes the internal state array,
 * with an array of 32-bit integers used as the seeds
 * @param init_key the array of 32-bit integers, used as a seed.
 * @param key_length the length of init_key.
 */
void
init_by_array (uint32_t * init_key, int key_length)
{
  int i, j, count;
  uint32_t r;
  int lag;
  int mid;
  int size = N * 4;

  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));
  if (key_length + 1 > N32)
    {
      count = key_length + 1;
    }
  else
    {
      count = N32;
    }
  r = func1 (psfmt32[idxof (0)] ^ psfmt32[idxof (mid)] ^ psfmt32[idxof (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) % N32)] ^ psfmt32[idxof ((i + N32 - 1) % N32)]);
      psfmt32[idxof ((i + mid) % N32)] += r;
      r += init_key[j] + i;
      psfmt32[idxof ((i + mid + lag) % N32)] += r;
      psfmt32[idxof (i)] = r;
      i = (i + 1) % N32;
    }
  for (; j < count; j++)
    {
      r = func1 (psfmt32[idxof (i)] ^ psfmt32[idxof ((i + mid) % N32)] ^ psfmt32[idxof ((i + N32 - 1) % N32)]);
      psfmt32[idxof ((i + mid) % N32)] += r;
      r += i;
      psfmt32[idxof ((i + mid + lag) % N32)] += r;
      psfmt32[idxof (i)] = r;
      i = (i + 1) % N32;
    }
  for (j = 0; j < N32; j++)
    {
      r = func2 (psfmt32[idxof (i)] + psfmt32[idxof ((i + mid) % N32)] + psfmt32[idxof ((i + N32 - 1) % N32)]);
      psfmt32[idxof ((i + mid) % N32)] ^= r;
      r -= i;
      psfmt32[idxof ((i + mid + lag) % N32)] ^= r;
      psfmt32[idxof (i)] = r;
      i = (i + 1) % N32;
    }

  idx = N32;
  period_certification ();
  initialized = 1;
}
Revision:	1.4
Committed:	Sat Sep 22 14:27:30 2007 UTC (18 years, 11 months ago) by pippijn
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.3:	+1 -1 lines
State:	*FILE REMOVED*
Log Message:	split up ermyth into ermyth-modules, libermyth (currently just ermyth-util) and ermyth-core