1 /* Implementation of the BESSEL_JN and BESSEL_YN transformational 2 function using a recurrence algorithm. 3 Copyright (C) 2010-2020 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 29 30 31 #if defined(GFC_REAL_16_IS_FLOAT128) 32 #define MATHFUNC(funcname) funcname ## q 33 #else 34 #define MATHFUNC(funcname) funcname ## l 35 #endif 36 37 #if defined (HAVE_GFC_REAL_16) 38 39 40 41 #if (defined(GFC_REAL_16_IS_FLOAT128) || defined(HAVE_JNL)) 42 extern void bessel_jn_r16 (gfc_array_r16 * const restrict ret, int n1, 43 int n2, GFC_REAL_16 x); 44 export_proto(bessel_jn_r16); 45 46 void 47 bessel_jn_r16 (gfc_array_r16 * const restrict ret, int n1, int n2, GFC_REAL_16 x) 48 { 49 int i; 50 index_type stride; 51 52 GFC_REAL_16 last1, last2, x2rev; 53 54 stride = GFC_DESCRIPTOR_STRIDE(ret,0); 55 56 if (ret->base_addr == NULL) 57 { 58 size_t size = n2 < n1 ? 0 : n2-n1+1; 59 GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1); 60 ret->base_addr = xmallocarray (size, sizeof (GFC_REAL_16)); 61 ret->offset = 0; 62 } 63 64 if (unlikely (n2 < n1)) 65 return; 66 67 if (unlikely (compile_options.bounds_check) 68 && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1)) 69 runtime_error("Incorrect extent in return value of BESSEL_JN " 70 "(%ld vs. %ld)", (long int) n2-n1, 71 (long int) GFC_DESCRIPTOR_EXTENT(ret,0)); 72 73 stride = GFC_DESCRIPTOR_STRIDE(ret,0); 74 75 if (unlikely (x == 0)) 76 { 77 ret->base_addr[0] = 1; 78 for (i = 1; i <= n2-n1; i++) 79 ret->base_addr[i*stride] = 0; 80 return; 81 } 82 83 last1 = MATHFUNC(jn) (n2, x); 84 ret->base_addr[(n2-n1)*stride] = last1; 85 86 if (n1 == n2) 87 return; 88 89 last2 = MATHFUNC(jn) (n2 - 1, x); 90 ret->base_addr[(n2-n1-1)*stride] = last2; 91 92 if (n1 + 1 == n2) 93 return; 94 95 x2rev = GFC_REAL_16_LITERAL(2.)/x; 96 97 for (i = n2-n1-2; i >= 0; i--) 98 { 99 ret->base_addr[i*stride] = x2rev * (i+1+n1) * last2 - last1; 100 last1 = last2; 101 last2 = ret->base_addr[i*stride]; 102 } 103 } 104 105 #endif 106 107 #if (defined(GFC_REAL_16_IS_FLOAT128) || defined(HAVE_YNL)) 108 extern void bessel_yn_r16 (gfc_array_r16 * const restrict ret, 109 int n1, int n2, GFC_REAL_16 x); 110 export_proto(bessel_yn_r16); 111 112 void 113 bessel_yn_r16 (gfc_array_r16 * const restrict ret, int n1, int n2, 114 GFC_REAL_16 x) 115 { 116 int i; 117 index_type stride; 118 119 GFC_REAL_16 last1, last2, x2rev; 120 121 stride = GFC_DESCRIPTOR_STRIDE(ret,0); 122 123 if (ret->base_addr == NULL) 124 { 125 size_t size = n2 < n1 ? 0 : n2-n1+1; 126 GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1); 127 ret->base_addr = xmallocarray (size, sizeof (GFC_REAL_16)); 128 ret->offset = 0; 129 } 130 131 if (unlikely (n2 < n1)) 132 return; 133 134 if (unlikely (compile_options.bounds_check) 135 && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1)) 136 runtime_error("Incorrect extent in return value of BESSEL_JN " 137 "(%ld vs. %ld)", (long int) n2-n1, 138 (long int) GFC_DESCRIPTOR_EXTENT(ret,0)); 139 140 stride = GFC_DESCRIPTOR_STRIDE(ret,0); 141 142 if (unlikely (x == 0)) 143 { 144 for (i = 0; i <= n2-n1; i++) 145 #if defined(GFC_REAL_16_INFINITY) 146 ret->base_addr[i*stride] = -GFC_REAL_16_INFINITY; 147 #else 148 ret->base_addr[i*stride] = -GFC_REAL_16_HUGE; 149 #endif 150 return; 151 } 152 153 last1 = MATHFUNC(yn) (n1, x); 154 ret->base_addr[0] = last1; 155 156 if (n1 == n2) 157 return; 158 159 last2 = MATHFUNC(yn) (n1 + 1, x); 160 ret->base_addr[1*stride] = last2; 161 162 if (n1 + 1 == n2) 163 return; 164 165 x2rev = GFC_REAL_16_LITERAL(2.)/x; 166 167 for (i = 2; i <= n2 - n1; i++) 168 { 169 #if defined(GFC_REAL_16_INFINITY) 170 if (unlikely (last2 == -GFC_REAL_16_INFINITY)) 171 { 172 ret->base_addr[i*stride] = -GFC_REAL_16_INFINITY; 173 } 174 else 175 #endif 176 { 177 ret->base_addr[i*stride] = x2rev * (i-1+n1) * last2 - last1; 178 last1 = last2; 179 last2 = ret->base_addr[i*stride]; 180 } 181 } 182 } 183 #endif 184 185 #endif 186 187