Random123-1.09: Random123/conventional/gsl_cbrng.h Source File

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# Random123/conventional/gsl_cbrng.h

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    00001 /*
    00002 Copyright 2010-2011, D. E. Shaw Research.
    00003 All rights reserved.
    00004
    00005 Redistribution and use in source and binary forms, with or without
    00006 modification, are permitted provided that the following conditions are
    00007 met:
    00008
    00009 * Redistributions of source code must retain the above copyright
    00010   notice, this list of conditions, and the following disclaimer.
    00011
    00012 * Redistributions in binary form must reproduce the above copyright
    00013   notice, this list of conditions, and the following disclaimer in the
    00014   documentation and/or other materials provided with the distribution.
    00015
    00016 * Neither the name of D. E. Shaw Research nor the names of its
    00017   contributors may be used to endorse or promote products derived from
    00018   this software without specific prior written permission.
    00019
    00020 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    00021 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    00022 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    00023 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    00024 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    00025 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    00026 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    00027 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    00028 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    00029 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    00030 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    00031 */
    00032 #ifndef __r123_compat_gslrng_dot_h__
    00033 #define __r123_compat_gslrng_dot_h__
    00034
    00035 #include <gsl/gsl_rng.h>
    00036 #include <string.h>
    00037
    00067 #define GSL_CBRNG(NAME, CBRNGNAME)                                      \
    00068 const gsl_rng_type *gsl_rng_##NAME;                                     \
    00069                                                                         \
    00070 typedef struct{                                                         \
    00071     CBRNGNAME##_ctr_t ctr;                                                   \
    00072     CBRNGNAME##_ctr_t r;                                                     \
    00073     CBRNGNAME##_key_t key;                                                   \
    00074     int elem;                                                           \
    00075 } NAME##_state;                                                         \
    00076                                                                         \
    00077 static unsigned long int NAME##_get(void *vstate){                      \
    00078     NAME##_state *st = (NAME##_state *)vstate;                          \
    00079     const int N=sizeof(st->ctr.v)/sizeof(st->ctr.v[0]);                 \
    00080     if( st->elem == 0 ){                                                \
    00081         ++st->ctr.v[0];                                                 \
    00082         if( N>1 && st->ctr.v[0] == 0 ) ++st->ctr.v[1];                  \
    00083         if( N>2 && st->ctr.v[1] == 0 ) ++st->ctr.v[2];                  \
    00084         if( N>3 && st->ctr.v[2] == 0 ) ++st->ctr.v[3];                  \
    00085         st->r = CBRNGNAME(st->ctr, st->key);                                 \
    00086         st->elem = N;                                                   \
    00087     }                                                                   \
    00088     return 0xffffffffUL & st->r.v[--st->elem];                          \
    00089 }                                                                       \
    00090                                                                         \
    00091 static double                                                           \
    00092 NAME##_get_double (void * vstate)                                       \
    00093 {                                                                       \
    00094     return NAME##_get (vstate)/4294967296.0;                            \
    00095 }                                                                       \
    00096                                                                         \
    00097 static void NAME##_set(void *vstate, unsigned long int s){              \
    00098     NAME##_state *st = (NAME##_state *)vstate;                          \
    00099     st->elem = 0;                                                       \
    00100     /* Assume that key and ctr have an array member, v,                 \
    00101        as if they are r123arrayNxW.  If not, this will fail             \
    00102        to compile.  In particular, this macro fails to compile          \
    00103        when the underlying CBRNG requires use of keyinit */             \
    00104     memset(&st->ctr.v[0], 0, sizeof(st->ctr.v));                        \
    00105     memset(&st->key.v[0], 0, sizeof(st->key.v));                        \
    00106     /* GSL 1.15 documentation says this about gsl_rng_set:              \
    00107          Note that the most generators only accept 32-bit seeds, with higher \
    00108          values being reduced modulo 2^32.  For generators with smaller \
    00109          ranges the maximum seed value will typically be lower.         \
    00110      so we won't jump through any hoops here to deal with               \
    00111      high bits if sizeof(unsigned long) > sizeof(uint32_t). */          \
    00112     st->key.v[0] = s;                                                   \
    00113 }                                                                       \
    00114                                                                         \
    00115 static const gsl_rng_type NAME##_type = {                               \
    00116     #NAME,                                                              \
    00117     0xffffffffUL,                                                       \
    00118     0,                                                                  \
    00119     sizeof(NAME##_state),                                               \
    00120     &NAME##_set,                                                        \
    00121     &NAME##_get,                                                        \
    00122     &NAME##_get_double                                                  \
    00123 };                                                                      \
    00124                                                                         \
    00125 const gsl_rng_type *gsl_rng_##NAME = &NAME##_type
    00126
    00127 #endif
    00128

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