1 `/* Specific implementation of the PACK intrinsic
2 Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008, 2009 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 3 of the License, or (at your option) any later version.
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.
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.
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/>. */
26 #include "libgfortran.h"
33 `#if defined (HAVE_'rtype_name`)
35 /* PACK is specified as follows:
37 13.14.80 PACK (ARRAY, MASK, [VECTOR])
39 Description: Pack an array into an array of rank one under the
42 Class: Transformational function.
45 ARRAY may be of any type. It shall not be scalar.
46 MASK shall be of type LOGICAL. It shall be conformable with ARRAY.
47 VECTOR (optional) shall be of the same type and type parameters
48 as ARRAY. VECTOR shall have at least as many elements as
49 there are true elements in MASK. If MASK is a scalar
50 with the value true, VECTOR shall have at least as many
51 elements as there are in ARRAY.
53 Result Characteristics: The result is an array of rank one with the
54 same type and type parameters as ARRAY. If VECTOR is present, the
55 result size is that of VECTOR; otherwise, the result size is the
56 number /t/ of true elements in MASK unless MASK is scalar with the
57 value true, in which case the result size is the size of ARRAY.
59 Result Value: Element /i/ of the result is the element of ARRAY
60 that corresponds to the /i/th true element of MASK, taking elements
61 in array element order, for /i/ = 1, 2, ..., /t/. If VECTOR is
62 present and has size /n/ > /t/, element /i/ of the result has the
63 value VECTOR(/i/), for /i/ = /t/ + 1, ..., /n/.
65 Examples: The nonzero elements of an array M with the value
67 | 9 0 0 | may be "gathered" by the function PACK. The result of
69 PACK (M, MASK = M.NE.0) is [9,7] and the result of PACK (M, M.NE.0,
70 VECTOR = (/ 2,4,6,8,10,12 /)) is [9,7,6,8,10,12].
72 There are two variants of the PACK intrinsic: one, where MASK is
73 array valued, and the other one where MASK is scalar. */
76 pack_'rtype_code` ('rtype` *ret, const 'rtype` *array,
77 const gfc_array_l1 *mask, const 'rtype` *vector)
79 /* r.* indicates the return array. */
81 'rtype_name` * restrict rptr;
82 /* s.* indicates the source array. */
83 index_type sstride[GFC_MAX_DIMENSIONS];
85 const 'rtype_name` *sptr;
86 /* m.* indicates the mask array. */
87 index_type mstride[GFC_MAX_DIMENSIONS];
89 const GFC_LOGICAL_1 *mptr;
91 index_type count[GFC_MAX_DIMENSIONS];
92 index_type extent[GFC_MAX_DIMENSIONS];
100 dim = GFC_DESCRIPTOR_RANK (array);
104 /* Use the same loop for all logical types, by using GFC_LOGICAL_1
105 and using shifting to address size and endian issues. */
107 mask_kind = GFC_DESCRIPTOR_SIZE (mask);
109 if (mask_kind == 1 || mask_kind == 2 || mask_kind == 4 || mask_kind == 8
110 #ifdef HAVE_GFC_LOGICAL_16
115 /* Do not convert a NULL pointer as we use test for NULL below. */
117 mptr = GFOR_POINTER_TO_L1 (mptr, mask_kind);
120 runtime_error ("Funny sized logical array");
123 for (n = 0; n < dim; n++)
126 extent[n] = array->dim[n].ubound + 1 - array->dim[n].lbound;
129 sstride[n] = array->dim[n].stride;
130 mstride[n] = mask->dim[n].stride * mask_kind;
135 mstride[0] = mask_kind;
142 if (ret->data == NULL || compile_options.bounds_check)
144 /* Count the elements, either for allocating memory or
145 for bounds checking. */
149 /* The return array will have as many
150 elements as there are in VECTOR. */
151 total = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
160 /* We have to count the true elements in MASK. */
162 /* TODO: We could speed up pack easily in the case of only
163 few .TRUE. entries in MASK, by keeping track of where we
164 would be in the source array during the initial traversal
165 of MASK, and caching the pointers to those elements. Then,
166 supposed the number of elements is small enough, we would
167 only have to traverse the list, and copy those elements
168 into the result array. In the case of datatypes which fit
169 in one of the integer types we could also cache the
170 value instead of a pointer to it.
171 This approach might be bad from the point of view of
172 cache behavior in the case where our cache is not big
173 enough to hold all elements that have to be copied. */
175 const GFC_LOGICAL_1 *m = mptr;
183 /* Test this element. */
187 /* Advance to the next element. */
191 while (count[n] == extent[n])
193 /* When we get to the end of a dimension, reset it
194 and increment the next dimension. */
196 /* We could precalculate this product, but this is a
197 less frequently used path so probably not worth
199 m -= mstride[n] * extent[n];
203 /* Break out of the loop. */
216 if (ret->data == NULL)
218 /* Setup the array descriptor. */
219 ret->dim[0].lbound = 0;
220 ret->dim[0].ubound = total - 1;
221 ret->dim[0].stride = 1;
226 /* In this case, nothing remains to be done. */
227 ret->data = internal_malloc_size (1);
231 ret->data = internal_malloc_size (sizeof ('rtype_name`) * total);
235 /* We come here because of range checking. */
236 index_type ret_extent;
238 ret_extent = ret->dim[0].ubound + 1 - ret->dim[0].lbound;
239 if (total != ret_extent)
240 runtime_error ("Incorrect extent in return value of PACK intrinsic;"
241 " is %ld, should be %ld", (long int) total,
242 (long int) ret_extent);
246 rstride0 = ret->dim[0].stride;
249 sstride0 = sstride[0];
250 mstride0 = mstride[0];
255 /* Test this element. */
262 /* Advance to the next element. */
267 while (count[n] == extent[n])
269 /* When we get to the end of a dimension, reset it and increment
270 the next dimension. */
272 /* We could precalculate these products, but this is a less
273 frequently used path so probably not worth it. */
274 sptr -= sstride[n] * extent[n];
275 mptr -= mstride[n] * extent[n];
279 /* Break out of the loop. */
292 /* Add any remaining elements from VECTOR. */
295 n = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
296 nelem = ((rptr - ret->data) / rstride0);
299 sstride0 = vector->dim[0].stride;
303 sptr = vector->data + sstride0 * nelem;