1 `/* Implementation of the BESSEL_JN and BESSEL_YN transformational
2 function using a recurrence algorithm.
3 Copyright (C) 2010-2019 Free Software Foundation, Inc.
4 Contributed by Tobias Burnus <burnus@net-b.de>
6 This file is part of the GNU Fortran runtime library (libgfortran).
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.
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.
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.
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/>. */
27 #include "libgfortran.h"'
30 include(`mtype.m4')dnl
34 `#if defined (HAVE_'rtype_name`)
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`);
44 bessel_jn_r'rtype_kind` ('rtype` * const restrict ret, int n1, int n2, 'rtype_name` x)
49 'rtype_name` last1, last2, x2rev;
51 stride = GFC_DESCRIPTOR_STRIDE(ret,0);
53 if (ret->base_addr == NULL)
55 size_t size = n2 < n1 ? 0 : n2-n1+1;
56 GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1);
57 ret->base_addr = xmallocarray (size, sizeof ('rtype_name`));
61 if (unlikely (n2 < n1))
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 (long int) GFC_DESCRIPTOR_EXTENT(ret,0));
70 stride = GFC_DESCRIPTOR_STRIDE(ret,0);
72 if (unlikely (x == 0))
74 ret->base_addr[0] = 1;
75 for (i = 1; i <= n2-n1; i++)
76 ret->base_addr[i*stride] = 0;
80 last1 = MATHFUNC(jn) (n2, x);
81 ret->base_addr[(n2-n1)*stride] = last1;
86 last2 = MATHFUNC(jn) (n2 - 1, x);
87 ret->base_addr[(n2-n1-1)*stride] = last2;
92 x2rev = GFC_REAL_'rtype_kind`_LITERAL(2.)/x;
94 for (i = n2-n1-2; i >= 0; i--)
96 ret->base_addr[i*stride] = x2rev * (i+1+n1) * last2 - last1;
98 last2 = ret->base_addr[i*stride];
104 #if 'hasmathfunc(yn)`
105 extern void bessel_yn_r'rtype_kind` ('rtype` * const restrict ret,
106 int n1, int n2, 'rtype_name` x);
107 export_proto(bessel_yn_r'rtype_kind`);
110 bessel_yn_r'rtype_kind` ('rtype` * const restrict ret, int n1, int n2,
116 'rtype_name` last1, last2, x2rev;
118 stride = GFC_DESCRIPTOR_STRIDE(ret,0);
120 if (ret->base_addr == NULL)
122 size_t size = n2 < n1 ? 0 : n2-n1+1;
123 GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1);
124 ret->base_addr = xmallocarray (size, sizeof ('rtype_name`));
128 if (unlikely (n2 < n1))
131 if (unlikely (compile_options.bounds_check)
132 && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1))
133 runtime_error("Incorrect extent in return value of BESSEL_JN "
134 "(%ld vs. %ld)", (long int) n2-n1,
135 (long int) GFC_DESCRIPTOR_EXTENT(ret,0));
137 stride = GFC_DESCRIPTOR_STRIDE(ret,0);
139 if (unlikely (x == 0))
141 for (i = 0; i <= n2-n1; i++)
142 #if defined('rtype_name`_INFINITY)
143 ret->base_addr[i*stride] = -'rtype_name`_INFINITY;
145 ret->base_addr[i*stride] = -'rtype_name`_HUGE;
150 last1 = MATHFUNC(yn) (n1, x);
151 ret->base_addr[0] = last1;
156 last2 = MATHFUNC(yn) (n1 + 1, x);
157 ret->base_addr[1*stride] = last2;
162 x2rev = GFC_REAL_'rtype_kind`_LITERAL(2.)/x;
164 for (i = 2; i <= n2 - n1; i++)
166 #if defined('rtype_name`_INFINITY)
167 if (unlikely (last2 == -'rtype_name`_INFINITY))
169 ret->base_addr[i*stride] = -'rtype_name`_INFINITY;
174 ret->base_addr[i*stride] = x2rev * (i-1+n1) * last2 - last1;
176 last2 = ret->base_addr[i*stride];