libgfortran/m4/bessel.m4

   1 `/* Implementation of the BESSEL_JN and BESSEL_YN transformational
   2    function using a recurrence algorithm.
   3    Copyright 2010 Free Software Foundation, Inc.
   4    Contributed by Tobias Burnus <burnus@net-b.de>
   5
   6 This file is part of the GNU Fortran runtime library (libgfortran).
   7
   8 Libgfortran is free software; you can redistribute it and/or
   9 modify it under the terms of the GNU General Public
  10 License as published by the Free Software Foundation; either
  11 version 3 of the License, or (at your option) any later version.
  12
  13 Libgfortran is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  */
  26
  27 #include "libgfortran.h"
  28 #include <stdlib.h>
  29 #include <assert.h>'
  30
  31 include(iparm.m4)dnl
  32 include(`mtype.m4')dnl
  33
  34 `#if defined (HAVE_'rtype_name`)
  35
  36
  37
  38 #if defined (HAVE_JN'Q`)
  39 extern void bessel_jn_r'rtype_kind` ('rtype` * const restrict ret, int n1,
  40                                      int n2, 'rtype_name` x);
  41 export_proto(bessel_jn_r'rtype_kind`);
  42
  43 void
  44 bessel_jn_r'rtype_kind` ('rtype` * const restrict ret, int n1, int n2, 'rtype_name` x)
  45 {
  46   int i;
  47   index_type stride;
  48
  49   'rtype_name` last1, last2, x2rev;
  50
  51   stride = GFC_DESCRIPTOR_STRIDE(ret,0);
  52
  53   if (ret->data == NULL)
  54     {
  55       size_t size = n2 < n1 ? 0 : n2-n1+1;
  56       GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1);
  57       ret->data = internal_malloc_size (sizeof ('rtype_name`) * size);
  58       ret->offset = 0;
  59     }
  60
  61   if (unlikely (n2 < n1))
  62     return;
  63
  64   if (unlikely (compile_options.bounds_check)
  65       && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1))
  66     runtime_error("Incorrect extent in return value of BESSEL_JN "
  67                   "(%ld vs. %ld)", (long int) n2-n1,
  68                   GFC_DESCRIPTOR_EXTENT(ret,0));
  69
  70   stride = GFC_DESCRIPTOR_STRIDE(ret,0);
  71
  72   if (unlikely (x == 0.0'Q`))
  73     {
  74       ret->data[0] = 1.0'Q`;
  75       for (i = 1; i <= n2-n1; i++)
  76         ret->data[i*stride] = 0.0'Q`;
  77       return;
  78     }
  79
  80   ret->data = ret->data;
  81   last1 = jn'q` (n2, x);
  82   ret->data[(n2-n1)*stride] = last1;
  83
  84   if (n1 == n2)
  85     return;
  86
  87   last2 = jn'q` (n2 - 1, x);
  88   ret->data[(n2-n1-1)*stride] = last2;
  89
  90   if (n1 + 1 == n2)
  91     return;
  92
  93   x2rev = 2.0'Q`/x;
  94
  95   for (i = n2-n1-2; i >= 0; i--)
  96     {
  97       ret->data[i*stride] = x2rev * (i+1+n1) * last2 - last1;
  98       last1 = last2;
  99       last2 = ret->data[i*stride];
 100     }
 101 }
 102
 103 #endif
 104
 105 #if defined (HAVE_YN'Q`)
 106 extern void bessel_yn_r'rtype_kind` ('rtype` * const restrict ret,
 107                                      int n1, int n2, 'rtype_name` x);
 108 export_proto(bessel_yn_r'rtype_kind`);
 109
 110 void
 111 bessel_yn_r'rtype_kind` ('rtype` * const restrict ret, int n1, int n2,
 112                          'rtype_name` x)
 113 {
 114   int i;
 115   index_type stride;
 116
 117   'rtype_name` last1, last2, x2rev;
 118
 119   stride = GFC_DESCRIPTOR_STRIDE(ret,0);
 120
 121   if (ret->data == NULL)
 122     {
 123       size_t size = n2 < n1 ? 0 : n2-n1+1;
 124       GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1);
 125       ret->data = internal_malloc_size (sizeof ('rtype_name`) * size);
 126       ret->offset = 0;
 127     }
 128
 129   if (unlikely (n2 < n1))
 130     return;
 131
 132   if (unlikely (compile_options.bounds_check)
 133       && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1))
 134     runtime_error("Incorrect extent in return value of BESSEL_JN "
 135                   "(%ld vs. %ld)", (long int) n2-n1,
 136                   GFC_DESCRIPTOR_EXTENT(ret,0));
 137
 138   stride = GFC_DESCRIPTOR_STRIDE(ret,0);
 139
 140   if (unlikely (x == 0.0'Q`))
 141     {
 142       for (i = 0; i <= n2-n1; i++)
 143 #if defined('rtype_name`_INFINITY)
 144         ret->data[i*stride] = -'rtype_name`_INFINITY;
 145 #else
 146         ret->data[i*stride] = -'rtype_name`_HUGE;
 147 #endif
 148       return;
 149     }
 150
 151   ret->data = ret->data;
 152   last1 = yn'q` (n1, x);
 153   ret->data[0] = last1;
 154
 155   if (n1 == n2)
 156     return;
 157
 158   last2 = yn'q` (n1 + 1, x);
 159   ret->data[1*stride] = last2;
 160
 161   if (n1 + 1 == n2)
 162     return;
 163
 164   x2rev = 2.0'Q`/x;
 165
 166   for (i = 2; i <= n1+n2; i++)
 167     {
 168 #if defined('rtype_name`_INFINITY)
 169       if (unlikely (last2 == -'rtype_name`_INFINITY))
 170         {
 171           ret->data[i*stride] = -'rtype_name`_INFINITY;
 172         }
 173       else
 174 #endif
 175         {
 176           ret->data[i*stride] = x2rev * (i-1+n1) * last2 - last1;
 177           last1 = last2;
 178           last2 = ret->data[i*stride];
 179         }
 180     }
 181 }
 182 #endif
 183
 184 #endif'
 185