libgfortran/intrinsics/reshape_generic.c

   1 /* Generic implementation of the RESHAPE intrinsic
   2    Copyright 2002, 2006, 2007 Free Software Foundation, Inc.
   3    Contributed by Paul Brook <paul@nowt.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 2 of the License, or (at your option) any later version.
  11
  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
  19 executable.)
  20
  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.
  25
  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.  */
  30
  31 #include "libgfortran.h"
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <assert.h>
  35
  36 typedef GFC_ARRAY_DESCRIPTOR(1, index_type) shape_type;
  37 typedef GFC_ARRAY_DESCRIPTOR(GFC_MAX_DIMENSIONS, char) parray;
  38
  39 static void
  40 reshape_internal (parray *ret, parray *source, shape_type *shape,
  41                   parray *pad, shape_type *order, index_type size)
  42 {
  43   /* r.* indicates the return array.  */
  44   index_type rcount[GFC_MAX_DIMENSIONS];
  45   index_type rextent[GFC_MAX_DIMENSIONS];
  46   index_type rstride[GFC_MAX_DIMENSIONS];
  47   index_type rstride0;
  48   index_type rdim;
  49   index_type rsize;
  50   index_type rs;
  51   index_type rex;
  52   char * restrict rptr;
  53   /* s.* indicates the source array.  */
  54   index_type scount[GFC_MAX_DIMENSIONS];
  55   index_type sextent[GFC_MAX_DIMENSIONS];
  56   index_type sstride[GFC_MAX_DIMENSIONS];
  57   index_type sstride0;
  58   index_type sdim;
  59   index_type ssize;
  60   const char *sptr;
  61   /* p.* indicates the pad array.  */
  62   index_type pcount[GFC_MAX_DIMENSIONS];
  63   index_type pextent[GFC_MAX_DIMENSIONS];
  64   index_type pstride[GFC_MAX_DIMENSIONS];
  65   index_type pdim;
  66   index_type psize;
  67   const char *pptr;
  68
  69   const char *src;
  70   int n;
  71   int dim;
  72   int sempty, pempty, shape_empty;
  73   index_type shape_data[GFC_MAX_DIMENSIONS];
  74
  75   rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
  76   if (rdim != GFC_DESCRIPTOR_RANK(ret))
  77     runtime_error("rank of return array incorrect in RESHAPE intrinsic");
  78
  79   shape_empty = 0;
  80
  81   for (n = 0; n < rdim; n++)
  82     {
  83       shape_data[n] = shape->data[n * shape->dim[0].stride];
  84       if (shape_data[n] <= 0)
  85         {
  86           shape_data[n] = 0;
  87           shape_empty = 1;
  88         }
  89     }
  90
  91   if (ret->data == NULL)
  92     {
  93       rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
  94       rs = 1;
  95       for (n = 0; n < rdim; n++)
  96         {
  97           ret->dim[n].lbound = 0;
  98           rex = shape_data[n];
  99           ret->dim[n].ubound =  rex - 1;
 100           ret->dim[n].stride = rs;
 101           rs *= rex;
 102         }
 103       ret->offset = 0;
 104       ret->data = internal_malloc_size ( rs * size );
 105       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
 106     }
 107
 108   if (shape_empty)
 109     return;
 110
 111   if (pad)
 112     {
 113       pdim = GFC_DESCRIPTOR_RANK (pad);
 114       psize = 1;
 115       pempty = 0;
 116       for (n = 0; n < pdim; n++)
 117         {
 118           pcount[n] = 0;
 119           pstride[n] = pad->dim[n].stride;
 120           pextent[n] = pad->dim[n].ubound + 1 - pad->dim[n].lbound;
 121           if (pextent[n] <= 0)
 122             {
 123               pempty = 1;
 124               pextent[n] = 0;
 125             }
 126
 127           if (psize == pstride[n])
 128             psize *= pextent[n];
 129           else
 130             psize = 0;
 131         }
 132       pptr = pad->data;
 133     }
 134   else
 135     {
 136       pdim = 0;
 137       psize = 1;
 138       pempty = 1;
 139       pptr = NULL;
 140     }
 141
 142   if (unlikely (compile_options.bounds_check))
 143     {
 144       index_type ret_extent, source_extent;
 145
 146       rs = 1;
 147       for (n = 0; n < rdim; n++)
 148         {
 149           rs *= shape_data[n];
 150           ret_extent = ret->dim[n].ubound + 1 - ret->dim[n].lbound;
 151           if (ret_extent != shape_data[n])
 152             runtime_error("Incorrect extent in return value of RESHAPE"
 153                           " intrinsic in dimension %ld: is %ld,"
 154                           " should be %ld", (long int) n+1,
 155                           (long int) ret_extent, (long int) shape_data[n]);
 156         }
 157
 158       source_extent = 1;
 159       sdim = GFC_DESCRIPTOR_RANK (source);
 160       for (n = 0; n < sdim; n++)
 161         {
 162           index_type se;
 163           se = source->dim[n].ubound + 1 - source->dim[0].lbound;
 164           source_extent *= se > 0 ? se : 0;
 165         }
 166
 167       if (rs > source_extent && (!pad || pempty))
 168         runtime_error("Incorrect size in SOURCE argument to RESHAPE"
 169                       " intrinsic: is %ld, should be %ld",
 170                       (long int) source_extent, (long int) rs);
 171
 172       if (order)
 173         {
 174           int seen[GFC_MAX_DIMENSIONS];
 175           index_type v;
 176
 177           for (n = 0; n < rdim; n++)
 178             seen[n] = 0;
 179
 180           for (n = 0; n < rdim; n++)
 181             {
 182               v = order->data[n * order->dim[0].stride] - 1;
 183
 184               if (v < 0 || v >= rdim)
 185                 runtime_error("Value %ld out of range in ORDER argument"
 186                               " to RESHAPE intrinsic", (long int) v + 1);
 187
 188               if (seen[v] != 0)
 189                 runtime_error("Duplicate value %ld in ORDER argument to"
 190                               " RESHAPE intrinsic", (long int) v + 1);
 191
 192               seen[v] = 1;
 193             }
 194         }
 195     }
 196
 197   rsize = 1;
 198   for (n = 0; n < rdim; n++)
 199     {
 200       if (order)
 201         dim = order->data[n * order->dim[0].stride] - 1;
 202       else
 203         dim = n;
 204
 205       rcount[n] = 0;
 206       rstride[n] = ret->dim[dim].stride;
 207       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
 208
 209       if (rextent[n] != shape_data[dim])
 210         runtime_error ("shape and target do not conform");
 211
 212       if (rsize == rstride[n])
 213         rsize *= rextent[n];
 214       else
 215         rsize = 0;
 216       if (rextent[n] <= 0)
 217         return;
 218     }
 219
 220   sdim = GFC_DESCRIPTOR_RANK (source);
 221   ssize = 1;
 222   sempty = 0;
 223   for (n = 0; n < sdim; n++)
 224     {
 225       scount[n] = 0;
 226       sstride[n] = source->dim[n].stride;
 227       sextent[n] = source->dim[n].ubound + 1 - source->dim[n].lbound;
 228       if (sextent[n] <= 0)
 229         {
 230           sempty = 1;
 231           sextent[n] = 0;
 232         }
 233
 234       if (ssize == sstride[n])
 235         ssize *= sextent[n];
 236       else
 237         ssize = 0;
 238     }
 239
 240   if (rsize != 0 && ssize != 0 && psize != 0)
 241     {
 242       rsize *= size;
 243       ssize *= size;
 244       psize *= size;
 245       reshape_packed (ret->data, rsize, source->data, ssize,
 246                       pad ? pad->data : NULL, psize);
 247       return;
 248     }
 249   rptr = ret->data;
 250   src = sptr = source->data;
 251   rstride0 = rstride[0] * size;
 252   sstride0 = sstride[0] * size;
 253
 254   if (sempty && pempty)
 255     abort ();
 256
 257   if (sempty)
 258     {
 259       /* Pretend we are using the pad array the first time around, too.  */
 260       src = pptr;
 261       sptr = pptr;
 262       sdim = pdim;
 263       for (dim = 0; dim < pdim; dim++)
 264         {
 265           scount[dim] = pcount[dim];
 266           sextent[dim] = pextent[dim];
 267           sstride[dim] = pstride[dim];
 268           sstride0 = pstride[0] * size;
 269         }
 270     }
 271
 272   while (rptr)
 273     {
 274       /* Select between the source and pad arrays.  */
 275       memcpy(rptr, src, size);
 276       /* Advance to the next element.  */
 277       rptr += rstride0;
 278       src += sstride0;
 279       rcount[0]++;
 280       scount[0]++;
 281
 282       /* Advance to the next destination element.  */
 283       n = 0;
 284       while (rcount[n] == rextent[n])
 285         {
 286           /* When we get to the end of a dimension, reset it and increment
 287              the next dimension.  */
 288           rcount[n] = 0;
 289           /* We could precalculate these products, but this is a less
 290              frequently used path so probably not worth it.  */
 291           rptr -= rstride[n] * rextent[n] * size;
 292           n++;
 293           if (n == rdim)
 294             {
 295               /* Break out of the loop.  */
 296               rptr = NULL;
 297               break;
 298             }
 299           else
 300             {
 301               rcount[n]++;
 302               rptr += rstride[n] * size;
 303             }
 304         }
 305
 306       /* Advance to the next source element.  */
 307       n = 0;
 308       while (scount[n] == sextent[n])
 309         {
 310           /* When we get to the end of a dimension, reset it and increment
 311              the next dimension.  */
 312           scount[n] = 0;
 313           /* We could precalculate these products, but this is a less
 314              frequently used path so probably not worth it.  */
 315           src -= sstride[n] * sextent[n] * size;
 316           n++;
 317           if (n == sdim)
 318             {
 319               if (sptr && pad)
 320                 {
 321                   /* Switch to the pad array.  */
 322                   sptr = NULL;
 323                   sdim = pdim;
 324                   for (dim = 0; dim < pdim; dim++)
 325                     {
 326                       scount[dim] = pcount[dim];
 327                       sextent[dim] = pextent[dim];
 328                       sstride[dim] = pstride[dim];
 329                       sstride0 = sstride[0] * size;
 330                     }
 331                 }
 332               /* We now start again from the beginning of the pad array.  */
 333               src = pptr;
 334               break;
 335             }
 336           else
 337             {
 338               scount[n]++;
 339               src += sstride[n] * size;
 340             }
 341         }
 342     }
 343 }
 344
 345 extern void reshape (parray *, parray *, shape_type *, parray *, shape_type *);
 346 export_proto(reshape);
 347
 348 void
 349 reshape (parray *ret, parray *source, shape_type *shape, parray *pad,
 350          shape_type *order)
 351 {
 352   reshape_internal (ret, source, shape, pad, order,
 353                     GFC_DESCRIPTOR_SIZE (source));
 354 }
 355
 356
 357 extern void reshape_char (parray *, gfc_charlen_type, parray *, shape_type *,
 358                           parray *, shape_type *, gfc_charlen_type,
 359                           gfc_charlen_type);
 360 export_proto(reshape_char);
 361
 362 void
 363 reshape_char (parray *ret, gfc_charlen_type ret_length __attribute__((unused)),
 364               parray *source, shape_type *shape, parray *pad,
 365               shape_type *order, gfc_charlen_type source_length,
 366               gfc_charlen_type pad_length __attribute__((unused)))
 367 {
 368   reshape_internal (ret, source, shape, pad, order, source_length);
 369 }
 370
 371
 372 extern void reshape_char4 (parray *, gfc_charlen_type, parray *, shape_type *,
 373                            parray *, shape_type *, gfc_charlen_type,
 374                            gfc_charlen_type);
 375 export_proto(reshape_char4);
 376
 377 void
 378 reshape_char4 (parray *ret, gfc_charlen_type ret_length __attribute__((unused)),
 379                parray *source, shape_type *shape, parray *pad,
 380                shape_type *order, gfc_charlen_type source_length,
 381                gfc_charlen_type pad_length __attribute__((unused)))
 382 {
 383   reshape_internal (ret, source, shape, pad, order,
 384                     source_length * sizeof (gfc_char4_t));
 385 }