libgfortran/generated/bessel_r16.c

   1 /* Implementation of the BESSEL_JN and BESSEL_YN transformational
   2    function using a recurrence algorithm.
   3    Copyright 2010, 2012 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
  32
  33 #if defined(GFC_REAL_16_IS_FLOAT128)
  34 #define MATHFUNC(funcname) funcname ## q
  35 #else
  36 #define MATHFUNC(funcname) funcname ## l
  37 #endif
  38
  39 #if defined (HAVE_GFC_REAL_16)
  40
  41
  42
  43 #if (defined(GFC_REAL_16_IS_FLOAT128) || defined(HAVE_JNL))
  44 extern void bessel_jn_r16 (gfc_array_r16 * const restrict ret, int n1,
  45                                      int n2, GFC_REAL_16 x);
  46 export_proto(bessel_jn_r16);
  47
  48 void
  49 bessel_jn_r16 (gfc_array_r16 * const restrict ret, int n1, int n2, GFC_REAL_16 x)
  50 {
  51   int i;
  52   index_type stride;
  53
  54   GFC_REAL_16 last1, last2, x2rev;
  55
  56   stride = GFC_DESCRIPTOR_STRIDE(ret,0);
  57
  58   if (ret->base_addr == NULL)
  59     {
  60       size_t size = n2 < n1 ? 0 : n2-n1+1;
  61       GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1);
  62       ret->base_addr = internal_malloc_size (sizeof (GFC_REAL_16) * size);
  63       ret->offset = 0;
  64     }
  65
  66   if (unlikely (n2 < n1))
  67     return;
  68
  69   if (unlikely (compile_options.bounds_check)
  70       && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1))
  71     runtime_error("Incorrect extent in return value of BESSEL_JN "
  72                   "(%ld vs. %ld)", (long int) n2-n1,
  73                   (long int) GFC_DESCRIPTOR_EXTENT(ret,0));
  74
  75   stride = GFC_DESCRIPTOR_STRIDE(ret,0);
  76
  77   if (unlikely (x == 0))
  78     {
  79       ret->base_addr[0] = 1;
  80       for (i = 1; i <= n2-n1; i++)
  81         ret->base_addr[i*stride] = 0;
  82       return;
  83     }
  84
  85   last1 = MATHFUNC(jn) (n2, x);
  86   ret->base_addr[(n2-n1)*stride] = last1;
  87
  88   if (n1 == n2)
  89     return;
  90
  91   last2 = MATHFUNC(jn) (n2 - 1, x);
  92   ret->base_addr[(n2-n1-1)*stride] = last2;
  93
  94   if (n1 + 1 == n2)
  95     return;
  96
  97   x2rev = GFC_REAL_16_LITERAL(2.)/x;
  98
  99   for (i = n2-n1-2; i >= 0; i--)
 100     {
 101       ret->base_addr[i*stride] = x2rev * (i+1+n1) * last2 - last1;
 102       last1 = last2;
 103       last2 = ret->base_addr[i*stride];
 104     }
 105 }
 106
 107 #endif
 108
 109 #if (defined(GFC_REAL_16_IS_FLOAT128) || defined(HAVE_YNL))
 110 extern void bessel_yn_r16 (gfc_array_r16 * const restrict ret,
 111                                      int n1, int n2, GFC_REAL_16 x);
 112 export_proto(bessel_yn_r16);
 113
 114 void
 115 bessel_yn_r16 (gfc_array_r16 * const restrict ret, int n1, int n2,
 116                          GFC_REAL_16 x)
 117 {
 118   int i;
 119   index_type stride;
 120
 121   GFC_REAL_16 last1, last2, x2rev;
 122
 123   stride = GFC_DESCRIPTOR_STRIDE(ret,0);
 124
 125   if (ret->base_addr == NULL)
 126     {
 127       size_t size = n2 < n1 ? 0 : n2-n1+1;
 128       GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1);
 129       ret->base_addr = internal_malloc_size (sizeof (GFC_REAL_16) * size);
 130       ret->offset = 0;
 131     }
 132
 133   if (unlikely (n2 < n1))
 134     return;
 135
 136   if (unlikely (compile_options.bounds_check)
 137       && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1))
 138     runtime_error("Incorrect extent in return value of BESSEL_JN "
 139                   "(%ld vs. %ld)", (long int) n2-n1,
 140                   (long int) GFC_DESCRIPTOR_EXTENT(ret,0));
 141
 142   stride = GFC_DESCRIPTOR_STRIDE(ret,0);
 143
 144   if (unlikely (x == 0))
 145     {
 146       for (i = 0; i <= n2-n1; i++)
 147 #if defined(GFC_REAL_16_INFINITY)
 148         ret->base_addr[i*stride] = -GFC_REAL_16_INFINITY;
 149 #else
 150         ret->base_addr[i*stride] = -GFC_REAL_16_HUGE;
 151 #endif
 152       return;
 153     }
 154
 155   ret->base_addr = ret->base_addr;
 156   last1 = MATHFUNC(yn) (n1, x);
 157   ret->base_addr[0] = last1;
 158
 159   if (n1 == n2)
 160     return;
 161
 162   last2 = MATHFUNC(yn) (n1 + 1, x);
 163   ret->base_addr[1*stride] = last2;
 164
 165   if (n1 + 1 == n2)
 166     return;
 167
 168   x2rev = GFC_REAL_16_LITERAL(2.)/x;
 169
 170   for (i = 2; i <= n1+n2; i++)
 171     {
 172 #if defined(GFC_REAL_16_INFINITY)
 173       if (unlikely (last2 == -GFC_REAL_16_INFINITY))
 174         {
 175           ret->base_addr[i*stride] = -GFC_REAL_16_INFINITY;
 176         }
 177       else
 178 #endif
 179         {
 180           ret->base_addr[i*stride] = x2rev * (i-1+n1) * last2 - last1;
 181           last1 = last2;
 182           last2 = ret->base_addr[i*stride];
 183         }
 184     }
 185 }
 186 #endif
 187
 188 #endif
 189