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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 include(iparm.m4)dnl
32 include(`mtype.m4')dnl
33
34 mathfunc_macro
35
36 `#if defined (HAVE_'rtype_name`)
37
38
39
40 #if 'hasmathfunc(jn)`
41 extern void bessel_jn_r'rtype_kind` ('rtype` * const restrict ret, int n1,
42 int n2, 'rtype_name` x);
43 export_proto(bessel_jn_r'rtype_kind`);
44
45 void
46 bessel_jn_r'rtype_kind` ('rtype` * const restrict ret, int n1, int n2, 'rtype_name` x)
47 {
48 int i;
49 index_type stride;
50
51 'rtype_name` last1, last2, x2rev;
52
53 stride = GFC_DESCRIPTOR_STRIDE(ret,0);
54
55 if (ret->base_addr == NULL)
56 {
57 size_t size = n2 < n1 ? 0 : n2-n1+1;
58 GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1);
59 ret->base_addr = xmalloc (sizeof ('rtype_name`) * size);
60 ret->offset = 0;
61 }
62
63 if (unlikely (n2 < n1))
64 return;
65
66 if (unlikely (compile_options.bounds_check)
67 && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1))
68 runtime_error("Incorrect extent in return value of BESSEL_JN "
69 "(%ld vs. %ld)", (long int) n2-n1,
70 (long int) GFC_DESCRIPTOR_EXTENT(ret,0));
71
72 stride = GFC_DESCRIPTOR_STRIDE(ret,0);
73
74 if (unlikely (x == 0))
75 {
76 ret->base_addr[0] = 1;
77 for (i = 1; i <= n2-n1; i++)
78 ret->base_addr[i*stride] = 0;
79 return;
80 }
81
82 last1 = MATHFUNC(jn) (n2, x);
83 ret->base_addr[(n2-n1)*stride] = last1;
84
85 if (n1 == n2)
86 return;
87
88 last2 = MATHFUNC(jn) (n2 - 1, x);
89 ret->base_addr[(n2-n1-1)*stride] = last2;
90
91 if (n1 + 1 == n2)
92 return;
93
94 x2rev = GFC_REAL_'rtype_kind`_LITERAL(2.)/x;
95
96 for (i = n2-n1-2; i >= 0; i--)
97 {
98 ret->base_addr[i*stride] = x2rev * (i+1+n1) * last2 - last1;
99 last1 = last2;
100 last2 = ret->base_addr[i*stride];
101 }
102 }
103
104 #endif
105
106 #if 'hasmathfunc(yn)`
107 extern void bessel_yn_r'rtype_kind` ('rtype` * const restrict ret,
108 int n1, int n2, 'rtype_name` x);
109 export_proto(bessel_yn_r'rtype_kind`);
110
111 void
112 bessel_yn_r'rtype_kind` ('rtype` * const restrict ret, int n1, int n2,
113 'rtype_name` x)
114 {
115 int i;
116 index_type stride;
117
118 'rtype_name` last1, last2, x2rev;
119
120 stride = GFC_DESCRIPTOR_STRIDE(ret,0);
121
122 if (ret->base_addr == NULL)
123 {
124 size_t size = n2 < n1 ? 0 : n2-n1+1;
125 GFC_DIMENSION_SET(ret->dim[0], 0, size-1, 1);
126 ret->base_addr = xmalloc (sizeof ('rtype_name`) * size);
127 ret->offset = 0;
128 }
129
130 if (unlikely (n2 < n1))
131 return;
132
133 if (unlikely (compile_options.bounds_check)
134 && GFC_DESCRIPTOR_EXTENT(ret,0) != (n2-n1+1))
135 runtime_error("Incorrect extent in return value of BESSEL_JN "
136 "(%ld vs. %ld)", (long int) n2-n1,
137 (long int) GFC_DESCRIPTOR_EXTENT(ret,0));
138
139 stride = GFC_DESCRIPTOR_STRIDE(ret,0);
140
141 if (unlikely (x == 0))
142 {
143 for (i = 0; i <= n2-n1; i++)
144 #if defined('rtype_name`_INFINITY)
145 ret->base_addr[i*stride] = -'rtype_name`_INFINITY;
146 #else
147 ret->base_addr[i*stride] = -'rtype_name`_HUGE;
148 #endif
149 return;
150 }
151
152 last1 = MATHFUNC(yn) (n1, x);
153 ret->base_addr[0] = last1;
154
155 if (n1 == n2)
156 return;
157
158 last2 = MATHFUNC(yn) (n1 + 1, x);
159 ret->base_addr[1*stride] = last2;
160
161 if (n1 + 1 == n2)
162 return;
163
164 x2rev = GFC_REAL_'rtype_kind`_LITERAL(2.)/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->base_addr[i*stride] = -'rtype_name`_INFINITY;
172 }
173 else
174 #endif
175 {
176 ret->base_addr[i*stride] = x2rev * (i-1+n1) * last2 - last1;
177 last1 = last2;
178 last2 = ret->base_addr[i*stride];
179 }
180 }
181 }
182 #endif
183
184 #endif'
185