1 /* Implementation of the BESSEL_JN and BESSEL_YN transformational 2 function using a recurrence algorithm. 3 Copyright (C) 2010-2024 Free Software Foundation, Inc. 4 Contributed by Tobias Burnus <burnus (at) 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 29 30 31 #if defined(GFC_REAL_16_IS_FLOAT128) 32 #if defined(GFC_REAL_16_USE_IEC_60559) 33 #define MATHFUNC(funcname) funcname ## f128 34 #else 35 #define MATHFUNC(funcname) funcname ## q 36 #endif 37 #else 38 #define MATHFUNC(funcname) funcname ## l 39 #endif 40 41 #if defined (HAVE_GFC_REAL_16) 42 43 44 45 #if (defined(GFC_REAL_16_IS_FLOAT128) || defined(HAVE_JNL)) 46 extern void bessel_jn_r16 (gfc_array_r16 * const restrict ret, int n1, 47 int n2, GFC_REAL_16 x); 48 export_proto(bessel_jn_r16); 49 50 void 51 bessel_jn_r16 (gfc_array_r16 * const restrict ret, int n1, int n2, GFC_REAL_16 x) 52 { 53 int i; 54 index_type stride; 55 56 GFC_REAL_16 last1, last2, x2rev; 57 58 stride = GFC_DESCRIPTOR_STRIDE(ret,0); 59 60 if (ret->base_addr == NULL) 61 { 62 size_t size = n2 < n1 ? 0 : n2-n1+1; 63 GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1); 64 ret->base_addr = xmallocarray (size, sizeof (GFC_REAL_16)); 65 ret->offset = 0; 66 } 67 68 if (unlikely (n2 < n1)) 69 return; 70 71 if (unlikely (compile_options.bounds_check) 72 && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1)) 73 runtime_error("Incorrect extent in return value of BESSEL_JN " 74 "(%ld vs. %ld)", (long int) n2-n1, 75 (long int) GFC_DESCRIPTOR_EXTENT(ret,0)); 76 77 stride = GFC_DESCRIPTOR_STRIDE(ret,0); 78 79 if (unlikely (x == 0)) 80 { 81 ret->base_addr[0] = 1; 82 for (i = 1; i <= n2-n1; i++) 83 ret->base_addr[i*stride] = 0; 84 return; 85 } 86 87 last1 = MATHFUNC(jn) (n2, x); 88 ret->base_addr[(n2-n1)*stride] = last1; 89 90 if (n1 == n2) 91 return; 92 93 last2 = MATHFUNC(jn) (n2 - 1, x); 94 ret->base_addr[(n2-n1-1)*stride] = last2; 95 96 if (n1 + 1 == n2) 97 return; 98 99 x2rev = GFC_REAL_16_LITERAL(2.)/x; 100 101 for (i = n2-n1-2; i >= 0; i--) 102 { 103 ret->base_addr[i*stride] = x2rev * (i+1+n1) * last2 - last1; 104 last1 = last2; 105 last2 = ret->base_addr[i*stride]; 106 } 107 } 108 109 #endif 110 111 #if (defined(GFC_REAL_16_IS_FLOAT128) || defined(HAVE_YNL)) 112 extern void bessel_yn_r16 (gfc_array_r16 * const restrict ret, 113 int n1, int n2, GFC_REAL_16 x); 114 export_proto(bessel_yn_r16); 115 116 void 117 bessel_yn_r16 (gfc_array_r16 * const restrict ret, int n1, int n2, 118 GFC_REAL_16 x) 119 { 120 int i; 121 index_type stride; 122 123 GFC_REAL_16 last1, last2, x2rev; 124 125 stride = GFC_DESCRIPTOR_STRIDE(ret,0); 126 127 if (ret->base_addr == NULL) 128 { 129 size_t size = n2 < n1 ? 0 : n2-n1+1; 130 GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1); 131 ret->base_addr = xmallocarray (size, sizeof (GFC_REAL_16)); 132 ret->offset = 0; 133 } 134 135 if (unlikely (n2 < n1)) 136 return; 137 138 if (unlikely (compile_options.bounds_check) 139 && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1)) 140 runtime_error("Incorrect extent in return value of BESSEL_JN " 141 "(%ld vs. %ld)", (long int) n2-n1, 142 (long int) GFC_DESCRIPTOR_EXTENT(ret,0)); 143 144 stride = GFC_DESCRIPTOR_STRIDE(ret,0); 145 146 if (unlikely (x == 0)) 147 { 148 for (i = 0; i <= n2-n1; i++) 149 #if defined(GFC_REAL_16_INFINITY) 150 ret->base_addr[i*stride] = -GFC_REAL_16_INFINITY; 151 #else 152 ret->base_addr[i*stride] = -GFC_REAL_16_HUGE; 153 #endif 154 return; 155 } 156 157 last1 = MATHFUNC(yn) (n1, x); 158 ret->base_addr[0] = last1; 159 160 if (n1 == n2) 161 return; 162 163 last2 = MATHFUNC(yn) (n1 + 1, x); 164 ret->base_addr[1*stride] = last2; 165 166 if (n1 + 1 == n2) 167 return; 168 169 x2rev = GFC_REAL_16_LITERAL(2.)/x; 170 171 for (i = 2; i <= n2 - n1; i++) 172 { 173 #if defined(GFC_REAL_16_INFINITY) 174 if (unlikely (last2 == -GFC_REAL_16_INFINITY)) 175 { 176 ret->base_addr[i*stride] = -GFC_REAL_16_INFINITY; 177 } 178 else 179 #endif 180 { 181 ret->base_addr[i*stride] = x2rev * (i-1+n1) * last2 - last1; 182 last1 = last2; 183 last2 = ret->base_addr[i*stride]; 184 } 185 } 186 } 187 #endif 188 189 #endif 190 191
Indexes created Tue Mar 03 05:31:39 UTC 2026