1 /* Implementation of the NORM2 intrinsic
2 Copyright (C) 2010-2023 Free Software Foundation, Inc.
3 Contributed by Tobias Burnus <burnus@net-b.de>
4
5 This file is part of the GNU Fortran runtime library (libgfortran).
6
7 Libgfortran is free software; you can redistribute it and/or
8 modify it under the terms of the GNU General Public
9 License as published by the Free Software Foundation; either
10 version 3 of the License, or (at your option) any later version.
11
12 Libgfortran is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 Under Section 7 of GPL version 3, you are granted additional
18 permissions described in the GCC Runtime Library Exception, version
19 3.1, as published by the Free Software Foundation.
20
21 You should have received a copy of the GNU General Public License and
22 a copy of the GCC Runtime Library Exception along with this program;
23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 <http://www.gnu.org/licenses/>. */
25
26 #include "libgfortran.h"
27
28
29
30 #if defined (HAVE_GFC_REAL_10) && defined (HAVE_GFC_REAL_10) && defined (HAVE_SQRTL) && defined (HAVE_FABSL)
31
32 #define MATHFUNC(funcname) funcname ## l
33
34
35 extern void norm2_r10 (gfc_array_r10 * const restrict,
36 gfc_array_r10 * const restrict, const index_type * const restrict);
37 export_proto(norm2_r10);
38
39 void
40 norm2_r10 (gfc_array_r10 * const restrict retarray,
41 gfc_array_r10 * const restrict array,
42 const index_type * const restrict pdim)
43 {
44 index_type count[GFC_MAX_DIMENSIONS];
45 index_type extent[GFC_MAX_DIMENSIONS];
46 index_type sstride[GFC_MAX_DIMENSIONS];
47 index_type dstride[GFC_MAX_DIMENSIONS];
48 const GFC_REAL_10 * restrict base;
49 GFC_REAL_10 * restrict dest;
50 index_type rank;
51 index_type n;
52 index_type len;
53 index_type delta;
54 index_type dim;
55 int continue_loop;
56
57 /* Make dim zero based to avoid confusion. */
58 rank = GFC_DESCRIPTOR_RANK (array) - 1;
59 dim = (*pdim) - 1;
60
61 if (unlikely (dim < 0 || dim > rank))
62 {
63 runtime_error ("Dim argument incorrect in NORM intrinsic: "
64 "is %ld, should be between 1 and %ld",
65 (long int) dim + 1, (long int) rank + 1);
66 }
67
68 len = GFC_DESCRIPTOR_EXTENT(array,dim);
69 if (len < 0)
70 len = 0;
71 delta = GFC_DESCRIPTOR_STRIDE(array,dim);
72
73 for (n = 0; n < dim; n++)
74 {
75 sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n);
76 extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
77
78 if (extent[n] < 0)
79 extent[n] = 0;
80 }
81 for (n = dim; n < rank; n++)
82 {
83 sstride[n] = GFC_DESCRIPTOR_STRIDE(array, n + 1);
84 extent[n] = GFC_DESCRIPTOR_EXTENT(array, n + 1);
85
86 if (extent[n] < 0)
87 extent[n] = 0;
88 }
89
90 if (retarray->base_addr == NULL)
91 {
92 size_t alloc_size, str;
93
94 for (n = 0; n < rank; n++)
95 {
96 if (n == 0)
97 str = 1;
98 else
99 str = GFC_DESCRIPTOR_STRIDE(retarray,n-1) * extent[n-1];
100
101 GFC_DIMENSION_SET(retarray->dim[n], 0, extent[n] - 1, str);
102
103 }
104
105 retarray->offset = 0;
106 retarray->dtype.rank = rank;
107
108 alloc_size = GFC_DESCRIPTOR_STRIDE(retarray,rank-1) * extent[rank-1];
109
110 retarray->base_addr = xmallocarray (alloc_size, sizeof (GFC_REAL_10));
111 if (alloc_size == 0)
112 {
113 /* Make sure we have a zero-sized array. */
114 GFC_DIMENSION_SET(retarray->dim[0], 0, -1, 1);
115 return;
116
117 }
118 }
119 else
120 {
121 if (rank != GFC_DESCRIPTOR_RANK (retarray))
122 runtime_error ("rank of return array incorrect in"
123 " NORM intrinsic: is %ld, should be %ld",
124 (long int) (GFC_DESCRIPTOR_RANK (retarray)),
125 (long int) rank);
126
127 if (unlikely (compile_options.bounds_check))
128 bounds_ifunction_return ((array_t *) retarray, extent,
129 "return value", "NORM");
130 }
131
132 for (n = 0; n < rank; n++)
133 {
134 count[n] = 0;
135 dstride[n] = GFC_DESCRIPTOR_STRIDE(retarray,n);
136 if (extent[n] <= 0)
137 return;
138 }
139
140 base = array->base_addr;
141 dest = retarray->base_addr;
142
143 continue_loop = 1;
144 while (continue_loop)
145 {
146 const GFC_REAL_10 * restrict src;
147 GFC_REAL_10 result;
148 src = base;
149 {
150
151 GFC_REAL_10 scale;
152 result = 0;
153 scale = 1;
154 if (len <= 0)
155 *dest = 0;
156 else
157 {
158 #if ! defined HAVE_BACK_ARG
159 for (n = 0; n < len; n++, src += delta)
160 {
161 #endif
162
163 if (*src != 0)
164 {
165 GFC_REAL_10 absX, val;
166 absX = MATHFUNC(fabs) (*src);
167 if (scale < absX)
168 {
169 val = scale / absX;
170 result = 1 + result * val * val;
171 scale = absX;
172 }
173 else
174 {
175 val = absX / scale;
176 result += val * val;
177 }
178 }
179 }
180 result = scale * MATHFUNC(sqrt) (result);
181 *dest = result;
182 }
183 }
184 /* Advance to the next element. */
185 count[0]++;
186 base += sstride[0];
187 dest += dstride[0];
188 n = 0;
189 while (count[n] == extent[n])
190 {
191 /* When we get to the end of a dimension, reset it and increment
192 the next dimension. */
193 count[n] = 0;
194 /* We could precalculate these products, but this is a less
195 frequently used path so probably not worth it. */
196 base -= sstride[n] * extent[n];
197 dest -= dstride[n] * extent[n];
198 n++;
199 if (n >= rank)
200 {
201 /* Break out of the loop. */
202 continue_loop = 0;
203 break;
204 }
205 else
206 {
207 count[n]++;
208 base += sstride[n];
209 dest += dstride[n];
210 }
211 }
212 }
213 }
214
215 #endif