1 /* Implementation of the CSHIFT intrinsic.
2 Copyright (C) 2017-2023 Free Software Foundation, Inc.
3 Contributed by Thomas Koenig <tkoenig@gcc.gnu.org>
4
5 This file is part of the GNU Fortran 95 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 #include <string.h>
28
29 #if defined (HAVE_GFC_COMPLEX_17) && defined (HAVE_GFC_INTEGER_4)
30
31 void
32 cshift1_4_c17 (gfc_array_c17 * const restrict ret,
33 const gfc_array_c17 * const restrict array,
34 const gfc_array_i4 * const restrict h,
35 const GFC_INTEGER_4 * const restrict pwhich)
36 {
37 /* r.* indicates the return array. */
38 index_type rstride[GFC_MAX_DIMENSIONS];
39 index_type rstride0;
40 index_type roffset;
41 GFC_COMPLEX_17 *rptr;
42 GFC_COMPLEX_17 *dest;
43 /* s.* indicates the source array. */
44 index_type sstride[GFC_MAX_DIMENSIONS];
45 index_type sstride0;
46 index_type soffset;
47 const GFC_COMPLEX_17 *sptr;
48 const GFC_COMPLEX_17 *src;
49 /* h.* indicates the shift array. */
50 index_type hstride[GFC_MAX_DIMENSIONS];
51 index_type hstride0;
52 const GFC_INTEGER_4 *hptr;
53
54 index_type count[GFC_MAX_DIMENSIONS];
55 index_type extent[GFC_MAX_DIMENSIONS];
56 index_type rs_ex[GFC_MAX_DIMENSIONS];
57 index_type ss_ex[GFC_MAX_DIMENSIONS];
58 index_type hs_ex[GFC_MAX_DIMENSIONS];
59
60 index_type dim;
61 index_type len;
62 index_type n;
63 int which;
64 GFC_INTEGER_4 sh;
65
66 /* Bounds checking etc is already done by the caller. */
67
68 if (pwhich)
69 which = *pwhich - 1;
70 else
71 which = 0;
72
73 extent[0] = 1;
74 count[0] = 0;
75 n = 0;
76
77 /* Initialized for avoiding compiler warnings. */
78 roffset = 1;
79 soffset = 1;
80 len = 0;
81
82 for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
83 {
84 if (dim == which)
85 {
86 roffset = GFC_DESCRIPTOR_STRIDE(ret,dim);
87 if (roffset == 0)
88 roffset = 1;
89 soffset = GFC_DESCRIPTOR_STRIDE(array,dim);
90 if (soffset == 0)
91 soffset = 1;
92 len = GFC_DESCRIPTOR_EXTENT(array,dim);
93 }
94 else
95 {
96 count[n] = 0;
97 extent[n] = GFC_DESCRIPTOR_EXTENT(array,dim);
98 rstride[n] = GFC_DESCRIPTOR_STRIDE(ret,dim);
99 sstride[n] = GFC_DESCRIPTOR_STRIDE(array,dim);
100 hstride[n] = GFC_DESCRIPTOR_STRIDE(h,n);
101 rs_ex[n] = rstride[n] * extent[n];
102 ss_ex[n] = sstride[n] * extent[n];
103 hs_ex[n] = hstride[n] * extent[n];
104 n++;
105 }
106 }
107 if (sstride[0] == 0)
108 sstride[0] = 1;
109 if (rstride[0] == 0)
110 rstride[0] = 1;
111 if (hstride[0] == 0)
112 hstride[0] = 1;
113
114 dim = GFC_DESCRIPTOR_RANK (array);
115 rstride0 = rstride[0];
116 sstride0 = sstride[0];
117 hstride0 = hstride[0];
118 rptr = ret->base_addr;
119 sptr = array->base_addr;
120 hptr = h->base_addr;
121
122 while (rptr)
123 {
124 /* Do the shift for this dimension. */
125 sh = *hptr;
126 /* Normal case should be -len < sh < len; try to
127 avoid the expensive remainder operation if possible. */
128 if (sh < 0)
129 sh += len;
130 if (unlikely(sh >= len || sh < 0))
131 {
132 sh = sh % len;
133 if (sh < 0)
134 sh += len;
135 }
136 src = &sptr[sh * soffset];
137 dest = rptr;
138 if (soffset == 1 && roffset == 1)
139 {
140 size_t len1 = sh * sizeof (GFC_COMPLEX_17);
141 size_t len2 = (len - sh) * sizeof (GFC_COMPLEX_17);
142 memcpy (rptr, sptr + sh, len2);
143 memcpy (rptr + (len - sh), sptr, len1);
144 }
145 else
146 {
147 for (n = 0; n < len - sh; n++)
148 {
149 *dest = *src;
150 dest += roffset;
151 src += soffset;
152 }
153 for (src = sptr, n = 0; n < sh; n++)
154 {
155 *dest = *src;
156 dest += roffset;
157 src += soffset;
158 }
159 }
160
161 /* Advance to the next section. */
162 rptr += rstride0;
163 sptr += sstride0;
164 hptr += hstride0;
165 count[0]++;
166 n = 0;
167 while (count[n] == extent[n])
168 {
169 /* When we get to the end of a dimension, reset it and increment
170 the next dimension. */
171 count[n] = 0;
172 rptr -= rs_ex[n];
173 sptr -= ss_ex[n];
174 hptr -= hs_ex[n];
175 n++;
176 if (n >= dim - 1)
177 {
178 /* Break out of the loop. */
179 rptr = NULL;
180 break;
181 }
182 else
183 {
184 count[n]++;
185 rptr += rstride[n];
186 sptr += sstride[n];
187 hptr += hstride[n];
188 }
189 }
190 }
191 }
192
193 #endif