1 /* Generic implementation of the PACK intrinsic
2 Copyright (C) 2002, 2004, 2005, 2006 Free Software Foundation, Inc.
3 Contributed by Paul Brook <paul@nowt.org>
5 This file is part of the GNU Fortran 95 runtime library (libgfortran).
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 2 of the License, or (at your option) any later version.
12 In addition to the permissions in the GNU General Public License, the
13 Free Software Foundation gives you unlimited permission to link the
14 compiled version of this file into combinations with other programs,
15 and to distribute those combinations without any restriction coming
16 from the use of this file. (The General Public License restrictions
17 do apply in other respects; for example, they cover modification of
18 the file, and distribution when not linked into a combine
21 Ligbfortran is distributed in the hope that it will be useful,
22 but WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 GNU General Public License for more details.
26 You should have received a copy of the GNU General Public
27 License along with libgfortran; see the file COPYING. If not,
28 write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
29 Boston, MA 02110-1301, USA. */
35 #include "libgfortran.h"
37 /* PACK is specified as follows:
39 13.14.80 PACK (ARRAY, MASK, [VECTOR])
41 Description: Pack an array into an array of rank one under the
44 Class: Transformational function.
47 ARRAY may be of any type. It shall not be scalar.
48 MASK shall be of type LOGICAL. It shall be conformable with ARRAY.
49 VECTOR (optional) shall be of the same type and type parameters
50 as ARRAY. VECTOR shall have at least as many elements as
51 there are true elements in MASK. If MASK is a scalar
52 with the value true, VECTOR shall have at least as many
53 elements as there are in ARRAY.
55 Result Characteristics: The result is an array of rank one with the
56 same type and type parameters as ARRAY. If VECTOR is present, the
57 result size is that of VECTOR; otherwise, the result size is the
58 number /t/ of true elements in MASK unless MASK is scalar with the
59 value true, in which case the result size is the size of ARRAY.
61 Result Value: Element /i/ of the result is the element of ARRAY
62 that corresponds to the /i/th true element of MASK, taking elements
63 in array element order, for /i/ = 1, 2, ..., /t/. If VECTOR is
64 present and has size /n/ > /t/, element /i/ of the result has the
65 value VECTOR(/i/), for /i/ = /t/ + 1, ..., /n/.
67 Examples: The nonzero elements of an array M with the value
69 | 9 0 0 | may be "gathered" by the function PACK. The result of
71 PACK (M, MASK = M.NE.0) is [9,7] and the result of PACK (M, M.NE.0,
72 VECTOR = (/ 2,4,6,8,10,12 /)) is [9,7,6,8,10,12].
74 There are two variants of the PACK intrinsic: one, where MASK is
75 array valued, and the other one where MASK is scalar. */
78 pack_internal (gfc_array_char *ret, const gfc_array_char *array,
79 const gfc_array_l4 *mask, const gfc_array_char *vector,
82 /* r.* indicates the return array. */
85 /* s.* indicates the source array. */
86 index_type sstride[GFC_MAX_DIMENSIONS];
89 /* m.* indicates the mask array. */
90 index_type mstride[GFC_MAX_DIMENSIONS];
92 const GFC_LOGICAL_4 *mptr;
94 index_type count[GFC_MAX_DIMENSIONS];
95 index_type extent[GFC_MAX_DIMENSIONS];
101 dim = GFC_DESCRIPTOR_RANK (array);
103 for (n = 0; n < dim; n++)
106 extent[n] = array->dim[n].ubound + 1 - array->dim[n].lbound;
109 sstride[n] = array->dim[n].stride * size;
110 mstride[n] = mask->dim[n].stride;
120 /* Use the same loop for both logical types. */
121 if (GFC_DESCRIPTOR_SIZE (mask) != 4)
123 if (GFC_DESCRIPTOR_SIZE (mask) != 8)
124 runtime_error ("Funny sized logical array");
125 for (n = 0; n < dim; n++)
127 mptr = GFOR_POINTER_L8_TO_L4 (mptr);
130 if (ret->data == NULL)
132 /* Allocate the memory for the result. */
137 /* The return array will have as many
138 elements as there are in VECTOR. */
139 total = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
143 /* We have to count the true elements in MASK. */
145 /* TODO: We could speed up pack easily in the case of only
146 few .TRUE. entries in MASK, by keeping track of where we
147 would be in the source array during the initial traversal
148 of MASK, and caching the pointers to those elements. Then,
149 supposed the number of elements is small enough, we would
150 only have to traverse the list, and copy those elements
151 into the result array. In the case of datatypes which fit
152 in one of the integer types we could also cache the
153 value instead of a pointer to it.
154 This approach might be bad from the point of view of
155 cache behavior in the case where our cache is not big
156 enough to hold all elements that have to be copied. */
158 const GFC_LOGICAL_4 *m = mptr;
166 /* Test this element. */
170 /* Advance to the next element. */
174 while (count[n] == extent[n])
176 /* When we get to the end of a dimension, reset it
177 and increment the next dimension. */
179 /* We could precalculate this product, but this is a
180 less frequently used path so probably not worth
182 m -= mstride[n] * extent[n];
186 /* Break out of the loop. */
199 /* Setup the array descriptor. */
200 ret->dim[0].lbound = 0;
201 ret->dim[0].ubound = total - 1;
202 ret->dim[0].stride = 1;
207 /* In this case, nothing remains to be done. */
208 ret->data = internal_malloc_size (1);
212 ret->data = internal_malloc_size (size * total);
215 rstride0 = ret->dim[0].stride * size;
218 sstride0 = sstride[0];
219 mstride0 = mstride[0];
224 /* Test this element. */
228 memcpy (rptr, sptr, size);
231 /* Advance to the next element. */
236 while (count[n] == extent[n])
238 /* When we get to the end of a dimension, reset it and increment
239 the next dimension. */
241 /* We could precalculate these products, but this is a less
242 frequently used path so probably not worth it. */
243 sptr -= sstride[n] * extent[n];
244 mptr -= mstride[n] * extent[n];
248 /* Break out of the loop. */
261 /* Add any remaining elements from VECTOR. */
264 n = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
265 nelem = ((rptr - ret->data) / rstride0);
268 sstride0 = vector->dim[0].stride * size;
272 sptr = vector->data + sstride0 * nelem;
276 memcpy (rptr, sptr, size);
284 extern void pack (gfc_array_char *, const gfc_array_char *,
285 const gfc_array_l4 *, const gfc_array_char *);
289 pack (gfc_array_char *ret, const gfc_array_char *array,
290 const gfc_array_l4 *mask, const gfc_array_char *vector)
292 pack_internal (ret, array, mask, vector, GFC_DESCRIPTOR_SIZE (array));
295 extern void pack_char (gfc_array_char *, GFC_INTEGER_4, const gfc_array_char *,
296 const gfc_array_l4 *, const gfc_array_char *,
297 GFC_INTEGER_4, GFC_INTEGER_4);
298 export_proto(pack_char);
301 pack_char (gfc_array_char *ret,
302 GFC_INTEGER_4 ret_length __attribute__((unused)),
303 const gfc_array_char *array, const gfc_array_l4 *mask,
304 const gfc_array_char *vector, GFC_INTEGER_4 array_length,
305 GFC_INTEGER_4 vector_length __attribute__((unused)))
307 pack_internal (ret, array, mask, vector, array_length);
311 pack_s_internal (gfc_array_char *ret, const gfc_array_char *array,
312 const GFC_LOGICAL_4 *mask, const gfc_array_char *vector,
315 /* r.* indicates the return array. */
318 /* s.* indicates the source array. */
319 index_type sstride[GFC_MAX_DIMENSIONS];
323 index_type count[GFC_MAX_DIMENSIONS];
324 index_type extent[GFC_MAX_DIMENSIONS];
330 dim = GFC_DESCRIPTOR_RANK (array);
332 for (n = 0; n < dim; n++)
335 extent[n] = array->dim[n].ubound + 1 - array->dim[n].lbound;
336 sstride[n] = array->dim[n].stride * size;
342 sstride0 = sstride[0];
345 if (ret->data == NULL)
347 /* Allocate the memory for the result. */
352 /* The return array will have as many elements as there are
354 total = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
360 /* The result array will have as many elements as the input
363 for (n = 1; n < dim; n++)
367 /* The result array will be empty. */
371 /* Setup the array descriptor. */
372 ret->dim[0].lbound = 0;
373 ret->dim[0].ubound = total - 1;
374 ret->dim[0].stride = 1;
379 ret->data = internal_malloc_size (1);
383 ret->data = internal_malloc_size (size * total);
386 rstride0 = ret->dim[0].stride * size;
391 /* The remaining possibilities are now:
392 If MASK is .TRUE., we have to copy the source array into the
393 result array. We then have to fill it up with elements from VECTOR.
394 If MASK is .FALSE., we have to copy VECTOR into the result
395 array. If VECTOR were not present we would have already returned. */
397 if (*mask && ssize != 0)
401 /* Add this element. */
402 memcpy (rptr, sptr, size);
405 /* Advance to the next element. */
409 while (count[n] == extent[n])
411 /* When we get to the end of a dimension, reset it and
412 increment the next dimension. */
414 /* We could precalculate these products, but this is a
415 less frequently used path so probably not worth it. */
416 sptr -= sstride[n] * extent[n];
420 /* Break out of the loop. */
433 /* Add any remaining elements from VECTOR. */
436 n = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
437 nelem = ((rptr - ret->data) / rstride0);
440 sstride0 = vector->dim[0].stride * size;
444 sptr = vector->data + sstride0 * nelem;
448 memcpy (rptr, sptr, size);
456 extern void pack_s (gfc_array_char *ret, const gfc_array_char *array,
457 const GFC_LOGICAL_4 *, const gfc_array_char *);
458 export_proto(pack_s);
461 pack_s (gfc_array_char *ret, const gfc_array_char *array,
462 const GFC_LOGICAL_4 *mask, const gfc_array_char *vector)
464 pack_s_internal (ret, array, mask, vector, GFC_DESCRIPTOR_SIZE (array));
467 extern void pack_s_char (gfc_array_char *ret, GFC_INTEGER_4,
468 const gfc_array_char *array, const GFC_LOGICAL_4 *,
469 const gfc_array_char *, GFC_INTEGER_4,
471 export_proto(pack_s_char);
474 pack_s_char (gfc_array_char *ret,
475 GFC_INTEGER_4 ret_length __attribute__((unused)),
476 const gfc_array_char *array, const GFC_LOGICAL_4 *mask,
477 const gfc_array_char *vector, GFC_INTEGER_4 array_length,
478 GFC_INTEGER_4 vector_length __attribute__((unused)))
480 pack_s_internal (ret, array, mask, vector, array_length);