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_l1 *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_1 *mptr;
94 index_type count[GFC_MAX_DIMENSIONS];
95 index_type extent[GFC_MAX_DIMENSIONS];
103 dim = GFC_DESCRIPTOR_RANK (array);
108 /* Use the same loop for all logical types, by using GFC_LOGICAL_1
109 and using shifting to address size and endian issues. */
111 mask_kind = GFC_DESCRIPTOR_SIZE (mask);
113 if (mask_kind == 1 || mask_kind == 2 || mask_kind == 4 || mask_kind == 8
114 #ifdef HAVE_GFC_LOGICAL_16
119 /* Don't convert a NULL pointer as we use test for NULL below. */
121 mptr = GFOR_POINTER_TO_L1 (mptr, mask_kind);
124 runtime_error ("Funny sized logical array");
127 for (n = 0; n < dim; n++)
130 extent[n] = array->dim[n].ubound + 1 - array->dim[n].lbound;
133 sstride[n] = array->dim[n].stride * size;
134 mstride[n] = mask->dim[n].stride * mask_kind;
139 mstride[0] = mask_kind;
141 if (ret->data == NULL || compile_options.bounds_check)
143 /* Count the elements, either for allocating memory or
144 for bounds checking. */
148 /* The return array will have as many
149 elements as there are in VECTOR. */
150 total = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
154 /* We have to count the true elements in MASK. */
156 /* TODO: We could speed up pack easily in the case of only
157 few .TRUE. entries in MASK, by keeping track of where we
158 would be in the source array during the initial traversal
159 of MASK, and caching the pointers to those elements. Then,
160 supposed the number of elements is small enough, we would
161 only have to traverse the list, and copy those elements
162 into the result array. In the case of datatypes which fit
163 in one of the integer types we could also cache the
164 value instead of a pointer to it.
165 This approach might be bad from the point of view of
166 cache behavior in the case where our cache is not big
167 enough to hold all elements that have to be copied. */
169 const GFC_LOGICAL_1 *m = mptr;
177 /* Test this element. */
181 /* Advance to the next element. */
185 while (count[n] == extent[n])
187 /* When we get to the end of a dimension, reset it
188 and increment the next dimension. */
190 /* We could precalculate this product, but this is a
191 less frequently used path so probably not worth
193 m -= mstride[n] * extent[n];
197 /* Break out of the loop. */
210 if (ret->data == NULL)
212 /* Setup the array descriptor. */
213 ret->dim[0].lbound = 0;
214 ret->dim[0].ubound = total - 1;
215 ret->dim[0].stride = 1;
220 /* In this case, nothing remains to be done. */
221 ret->data = internal_malloc_size (1);
225 ret->data = internal_malloc_size (size * total);
229 /* We come here because of range checking. */
230 index_type ret_extent;
232 ret_extent = ret->dim[0].ubound + 1 - ret->dim[0].lbound;
233 if (total != ret_extent)
234 runtime_error ("Incorrect extent in return value of PACK intrinsic;"
235 " is %ld, should be %ld", (long int) total,
236 (long int) ret_extent);
240 rstride0 = ret->dim[0].stride * size;
243 sstride0 = sstride[0];
244 mstride0 = mstride[0];
249 /* Test this element. */
253 memcpy (rptr, sptr, size);
256 /* Advance to the next element. */
261 while (count[n] == extent[n])
263 /* When we get to the end of a dimension, reset it and increment
264 the next dimension. */
266 /* We could precalculate these products, but this is a less
267 frequently used path so probably not worth it. */
268 sptr -= sstride[n] * extent[n];
269 mptr -= mstride[n] * extent[n];
273 /* Break out of the loop. */
286 /* Add any remaining elements from VECTOR. */
289 n = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
290 nelem = ((rptr - ret->data) / rstride0);
293 sstride0 = vector->dim[0].stride * size;
297 sptr = vector->data + sstride0 * nelem;
301 memcpy (rptr, sptr, size);
309 extern void pack (gfc_array_char *, const gfc_array_char *,
310 const gfc_array_l4 *, const gfc_array_char *);
314 pack (gfc_array_char *ret, const gfc_array_char *array,
315 const gfc_array_l4 *mask, const gfc_array_char *vector)
317 pack_internal (ret, array, mask, vector, GFC_DESCRIPTOR_SIZE (array));
320 extern void pack_char (gfc_array_char *, GFC_INTEGER_4, const gfc_array_char *,
321 const gfc_array_l4 *, const gfc_array_char *,
322 GFC_INTEGER_4, GFC_INTEGER_4);
323 export_proto(pack_char);
326 pack_char (gfc_array_char *ret,
327 GFC_INTEGER_4 ret_length __attribute__((unused)),
328 const gfc_array_char *array, const gfc_array_l4 *mask,
329 const gfc_array_char *vector, GFC_INTEGER_4 array_length,
330 GFC_INTEGER_4 vector_length __attribute__((unused)))
332 pack_internal (ret, array, mask, vector, array_length);
336 pack_s_internal (gfc_array_char *ret, const gfc_array_char *array,
337 const GFC_LOGICAL_4 *mask, const gfc_array_char *vector,
340 /* r.* indicates the return array. */
343 /* s.* indicates the source array. */
344 index_type sstride[GFC_MAX_DIMENSIONS];
348 index_type count[GFC_MAX_DIMENSIONS];
349 index_type extent[GFC_MAX_DIMENSIONS];
355 dim = GFC_DESCRIPTOR_RANK (array);
357 for (n = 0; n < dim; n++)
360 extent[n] = array->dim[n].ubound + 1 - array->dim[n].lbound;
361 sstride[n] = array->dim[n].stride * size;
367 sstride0 = sstride[0];
370 if (ret->data == NULL)
372 /* Allocate the memory for the result. */
377 /* The return array will have as many elements as there are
379 total = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
385 /* The result array will have as many elements as the input
388 for (n = 1; n < dim; n++)
392 /* The result array will be empty. */
396 /* Setup the array descriptor. */
397 ret->dim[0].lbound = 0;
398 ret->dim[0].ubound = total - 1;
399 ret->dim[0].stride = 1;
404 ret->data = internal_malloc_size (1);
408 ret->data = internal_malloc_size (size * total);
411 rstride0 = ret->dim[0].stride * size;
416 /* The remaining possibilities are now:
417 If MASK is .TRUE., we have to copy the source array into the
418 result array. We then have to fill it up with elements from VECTOR.
419 If MASK is .FALSE., we have to copy VECTOR into the result
420 array. If VECTOR were not present we would have already returned. */
422 if (*mask && ssize != 0)
426 /* Add this element. */
427 memcpy (rptr, sptr, size);
430 /* Advance to the next element. */
434 while (count[n] == extent[n])
436 /* When we get to the end of a dimension, reset it and
437 increment the next dimension. */
439 /* We could precalculate these products, but this is a
440 less frequently used path so probably not worth it. */
441 sptr -= sstride[n] * extent[n];
445 /* Break out of the loop. */
458 /* Add any remaining elements from VECTOR. */
461 n = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
462 nelem = ((rptr - ret->data) / rstride0);
465 sstride0 = vector->dim[0].stride * size;
469 sptr = vector->data + sstride0 * nelem;
473 memcpy (rptr, sptr, size);
481 extern void pack_s (gfc_array_char *ret, const gfc_array_char *array,
482 const GFC_LOGICAL_4 *, const gfc_array_char *);
483 export_proto(pack_s);
486 pack_s (gfc_array_char *ret, const gfc_array_char *array,
487 const GFC_LOGICAL_4 *mask, const gfc_array_char *vector)
489 pack_s_internal (ret, array, mask, vector, GFC_DESCRIPTOR_SIZE (array));
492 extern void pack_s_char (gfc_array_char *ret, GFC_INTEGER_4,
493 const gfc_array_char *array, const GFC_LOGICAL_4 *,
494 const gfc_array_char *, GFC_INTEGER_4,
496 export_proto(pack_s_char);
499 pack_s_char (gfc_array_char *ret,
500 GFC_INTEGER_4 ret_length __attribute__((unused)),
501 const gfc_array_char *array, const GFC_LOGICAL_4 *mask,
502 const gfc_array_char *vector, GFC_INTEGER_4 array_length,
503 GFC_INTEGER_4 vector_length __attribute__((unused)))
505 pack_s_internal (ret, array, mask, vector, array_length);