1 /* Specific implementation of the PACK intrinsic
2 Copyright (C) 2002-2023 Free Software Foundation, Inc.
3 Contributed by Paul Brook <paul@nowt.org>
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 Ligbfortran 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
30 #if defined (HAVE_GFC_REAL_17)
31
32 /* PACK is specified as follows:
33
34 13.14.80 PACK (ARRAY, MASK, [VECTOR])
35
36 Description: Pack an array into an array of rank one under the
37 control of a mask.
38
39 Class: Transformational function.
40
41 Arguments:
42 ARRAY may be of any type. It shall not be scalar.
43 MASK shall be of type LOGICAL. It shall be conformable with ARRAY.
44 VECTOR (optional) shall be of the same type and type parameters
45 as ARRAY. VECTOR shall have at least as many elements as
46 there are true elements in MASK. If MASK is a scalar
47 with the value true, VECTOR shall have at least as many
48 elements as there are in ARRAY.
49
50 Result Characteristics: The result is an array of rank one with the
51 same type and type parameters as ARRAY. If VECTOR is present, the
52 result size is that of VECTOR; otherwise, the result size is the
53 number /t/ of true elements in MASK unless MASK is scalar with the
54 value true, in which case the result size is the size of ARRAY.
55
56 Result Value: Element /i/ of the result is the element of ARRAY
57 that corresponds to the /i/th true element of MASK, taking elements
58 in array element order, for /i/ = 1, 2, ..., /t/. If VECTOR is
59 present and has size /n/ > /t/, element /i/ of the result has the
60 value VECTOR(/i/), for /i/ = /t/ + 1, ..., /n/.
61
62 Examples: The nonzero elements of an array M with the value
63 | 0 0 0 |
64 | 9 0 0 | may be "gathered" by the function PACK. The result of
65 | 0 0 7 |
66 PACK (M, MASK = M.NE.0) is [9,7] and the result of PACK (M, M.NE.0,
67 VECTOR = (/ 2,4,6,8,10,12 /)) is [9,7,6,8,10,12].
68
69 There are two variants of the PACK intrinsic: one, where MASK is
70 array valued, and the other one where MASK is scalar. */
71
72 void
73 pack_r17 (gfc_array_r17 *ret, const gfc_array_r17 *array,
74 const gfc_array_l1 *mask, const gfc_array_r17 *vector)
75 {
76 /* r.* indicates the return array. */
77 index_type rstride0;
78 GFC_REAL_17 * restrict rptr;
79 /* s.* indicates the source array. */
80 index_type sstride[GFC_MAX_DIMENSIONS];
81 index_type sstride0;
82 const GFC_REAL_17 *sptr;
83 /* m.* indicates the mask array. */
84 index_type mstride[GFC_MAX_DIMENSIONS];
85 index_type mstride0;
86 const GFC_LOGICAL_1 *mptr;
87
88 index_type count[GFC_MAX_DIMENSIONS];
89 index_type extent[GFC_MAX_DIMENSIONS];
90 int zero_sized;
91 index_type n;
92 index_type dim;
93 index_type nelem;
94 index_type total;
95 int mask_kind;
96
97 dim = GFC_DESCRIPTOR_RANK (array);
98
99 sstride[0] = 0; /* Avoid warnings if not initialized. */
100 mstride[0] = 0;
101
102 mptr = mask->base_addr;
103
104 /* Use the same loop for all logical types, by using GFC_LOGICAL_1
105 and using shifting to address size and endian issues. */
106
107 mask_kind = GFC_DESCRIPTOR_SIZE (mask);
108
109 if (mask_kind == 1 || mask_kind == 2 || mask_kind == 4 || mask_kind == 8
110 #ifdef HAVE_GFC_LOGICAL_16
111 || mask_kind == 16
112 #endif
113 )
114 {
115 /* Do not convert a NULL pointer as we use test for NULL below. */
116 if (mptr)
117 mptr = GFOR_POINTER_TO_L1 (mptr, mask_kind);
118 }
119 else
120 runtime_error ("Funny sized logical array");
121
122 zero_sized = 0;
123 for (n = 0; n < dim; n++)
124 {
125 count[n] = 0;
126 extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
127 if (extent[n] <= 0)
128 zero_sized = 1;
129 sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n);
130 mstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(mask,n);
131 }
132 if (sstride[0] == 0)
133 sstride[0] = 1;
134 if (mstride[0] == 0)
135 mstride[0] = mask_kind;
136
137 if (zero_sized)
138 sptr = NULL;
139 else
140 sptr = array->base_addr;
141
142 if (ret->base_addr == NULL || unlikely (compile_options.bounds_check))
143 {
144 /* Count the elements, either for allocating memory or
145 for bounds checking. */
146
147 if (vector != NULL)
148 {
149 /* The return array will have as many
150 elements as there are in VECTOR. */
151 total = GFC_DESCRIPTOR_EXTENT(vector,0);
152 if (total < 0)
153 {
154 total = 0;
155 vector = NULL;
156 }
157 }
158 else
159 {
160 /* We have to count the true elements in MASK. */
161 total = count_0 (mask);
162 }
163
164 if (ret->base_addr == NULL)
165 {
166 /* Setup the array descriptor. */
167 GFC_DIMENSION_SET(ret->dim[0], 0, total-1, 1);
168
169 ret->offset = 0;
170
171 /* xmallocarray allocates a single byte for zero size. */
172 ret->base_addr = xmallocarray (total, sizeof (GFC_REAL_17));
173
174 if (total == 0)
175 return;
176 }
177 else
178 {
179 /* We come here because of range checking. */
180 index_type ret_extent;
181
182 ret_extent = GFC_DESCRIPTOR_EXTENT(ret,0);
183 if (total != ret_extent)
184 runtime_error ("Incorrect extent in return value of PACK intrinsic;"
185 " is %ld, should be %ld", (long int) total,
186 (long int) ret_extent);
187 }
188 }
189
190 rstride0 = GFC_DESCRIPTOR_STRIDE(ret,0);
191 if (rstride0 == 0)
192 rstride0 = 1;
193 sstride0 = sstride[0];
194 mstride0 = mstride[0];
195 rptr = ret->base_addr;
196
197 while (sptr && mptr)
198 {
199 /* Test this element. */
200 if (*mptr)
201 {
202 /* Add it. */
203 *rptr = *sptr;
204 rptr += rstride0;
205 }
206 /* Advance to the next element. */
207 sptr += sstride0;
208 mptr += mstride0;
209 count[0]++;
210 n = 0;
211 while (count[n] == extent[n])
212 {
213 /* When we get to the end of a dimension, reset it and increment
214 the next dimension. */
215 count[n] = 0;
216 /* We could precalculate these products, but this is a less
217 frequently used path so probably not worth it. */
218 sptr -= sstride[n] * extent[n];
219 mptr -= mstride[n] * extent[n];
220 n++;
221 if (n >= dim)
222 {
223 /* Break out of the loop. */
224 sptr = NULL;
225 break;
226 }
227 else
228 {
229 count[n]++;
230 sptr += sstride[n];
231 mptr += mstride[n];
232 }
233 }
234 }
235
236 /* Add any remaining elements from VECTOR. */
237 if (vector)
238 {
239 n = GFC_DESCRIPTOR_EXTENT(vector,0);
240 nelem = ((rptr - ret->base_addr) / rstride0);
241 if (n > nelem)
242 {
243 sstride0 = GFC_DESCRIPTOR_STRIDE(vector,0);
244 if (sstride0 == 0)
245 sstride0 = 1;
246
247 sptr = vector->base_addr + sstride0 * nelem;
248 n -= nelem;
249 while (n--)
250 {
251 *rptr = *sptr;
252 rptr += rstride0;
253 sptr += sstride0;
254 }
255 }
256 }
257 }
258
259 #endif
260