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   rsize = 1;
 112   for (n = 0; n < rdim; n++)
 113     {
 114       if (order)
 115         dim = order->data[n * order->dim[0].stride] - 1;
 116       else
 117         dim = n;
 118
 119       rcount[n] = 0;
 120       rstride[n] = ret->dim[dim].stride;
 121       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
 122
 123       if (rextent[n] != shape_data[dim])
 124         runtime_error ("shape and target do not conform");
 125
 126       if (rsize == rstride[n])
 127         rsize *= rextent[n];
 128       else
 129         rsize = 0;
 130       if (rextent[n] <= 0)
 131         return;
 132     }
 133
 134   sdim = GFC_DESCRIPTOR_RANK (source);
 135   ssize = 1;
 136   sempty = 0;
 137   for (n = 0; n < sdim; n++)
 138     {
 139       scount[n] = 0;
 140       sstride[n] = source->dim[n].stride;
 141       sextent[n] = source->dim[n].ubound + 1 - source->dim[n].lbound;
 142       if (sextent[n] <= 0)
 143         {
 144           sempty = 1;
 145           sextent[n] = 0;
 146         }
 147
 148       if (ssize == sstride[n])
 149         ssize *= sextent[n];
 150       else
 151         ssize = 0;
 152     }
 153
 154   if (pad)
 155     {
 156       pdim = GFC_DESCRIPTOR_RANK (pad);
 157       psize = 1;
 158       pempty = 0;
 159       for (n = 0; n < pdim; n++)
 160         {
 161           pcount[n] = 0;
 162           pstride[n] = pad->dim[n].stride;
 163           pextent[n] = pad->dim[n].ubound + 1 - pad->dim[n].lbound;
 164           if (pextent[n] <= 0)
 165             {
 166               pempty = 1;
 167               pextent[n] = 0;
 168             }
 169
 170           if (psize == pstride[n])
 171             psize *= pextent[n];
 172           else
 173             psize = 0;
 174         }
 175       pptr = pad->data;
 176     }
 177   else
 178     {
 179       pdim = 0;
 180       psize = 1;
 181       pempty = 1;
 182       pptr = NULL;
 183     }
 184
 185   if (rsize != 0 && ssize != 0 && psize != 0)
 186     {
 187       rsize *= size;
 188       ssize *= size;
 189       psize *= size;
 190       reshape_packed (ret->data, rsize, source->data, ssize,
 191                       pad ? pad->data : NULL, psize);
 192       return;
 193     }
 194   rptr = ret->data;
 195   src = sptr = source->data;
 196   rstride0 = rstride[0] * size;
 197   sstride0 = sstride[0] * size;
 198
 199   if (sempty && pempty)
 200     abort ();
 201
 202   if (sempty)
 203     {
 204       /* Switch immediately to the pad array.  */
 205       src = pptr;
 206       sptr = NULL;
 207       sdim = pdim;
 208       for (dim = 0; dim < pdim; dim++)
 209         {
 210           scount[dim] = pcount[dim];
 211           sextent[dim] = pextent[dim];
 212           sstride[dim] = pstride[dim];
 213           sstride0 = sstride[0] * size;
 214         }
 215     }
 216
 217   while (rptr)
 218     {
 219       /* Select between the source and pad arrays.  */
 220       memcpy(rptr, src, size);
 221       /* Advance to the next element.  */
 222       rptr += rstride0;
 223       src += sstride0;
 224       rcount[0]++;
 225       scount[0]++;
 226
 227       /* Advance to the next destination element.  */
 228       n = 0;
 229       while (rcount[n] == rextent[n])
 230         {
 231           /* When we get to the end of a dimension, reset it and increment
 232              the next dimension.  */
 233           rcount[n] = 0;
 234           /* We could precalculate these products, but this is a less
 235              frequently used path so probably not worth it.  */
 236           rptr -= rstride[n] * rextent[n] * size;
 237           n++;
 238           if (n == rdim)
 239             {
 240               /* Break out of the loop.  */
 241               rptr = NULL;
 242               break;
 243             }
 244           else
 245             {
 246               rcount[n]++;
 247               rptr += rstride[n] * size;
 248             }
 249         }
 250
 251       /* Advance to the next source element.  */
 252       n = 0;
 253       while (scount[n] == sextent[n])
 254         {
 255           /* When we get to the end of a dimension, reset it and increment
 256              the next dimension.  */
 257           scount[n] = 0;
 258           /* We could precalculate these products, but this is a less
 259              frequently used path so probably not worth it.  */
 260           src -= sstride[n] * sextent[n] * size;
 261           n++;
 262           if (n == sdim)
 263             {
 264               if (sptr && pad)
 265                 {
 266                   /* Switch to the pad array.  */
 267                   sptr = NULL;
 268                   sdim = pdim;
 269                   for (dim = 0; dim < pdim; dim++)
 270                     {
 271                       scount[dim] = pcount[dim];
 272                       sextent[dim] = pextent[dim];
 273                       sstride[dim] = pstride[dim];
 274                       sstride0 = sstride[0] * size;
 275                     }
 276                 }
 277               /* We now start again from the beginning of the pad array.  */
 278               src = pptr;
 279               break;
 280             }
 281           else
 282             {
 283               scount[n]++;
 284               src += sstride[n] * size;
 285             }
 286         }
 287     }
 288 }
 289
 290 extern void reshape (parray *, parray *, shape_type *, parray *, shape_type *);
 291 export_proto(reshape);
 292
 293 void
 294 reshape (parray *ret, parray *source, shape_type *shape, parray *pad,
 295          shape_type *order)
 296 {
 297   reshape_internal (ret, source, shape, pad, order,
 298                     GFC_DESCRIPTOR_SIZE (source));
 299 }
 300
 301
 302 extern void reshape_char (parray *, gfc_charlen_type, parray *, shape_type *,
 303                           parray *, shape_type *, gfc_charlen_type,
 304                           gfc_charlen_type);
 305 export_proto(reshape_char);
 306
 307 void
 308 reshape_char (parray *ret, gfc_charlen_type ret_length __attribute__((unused)),
 309               parray *source, shape_type *shape, parray *pad,
 310               shape_type *order, gfc_charlen_type source_length,
 311               gfc_charlen_type pad_length __attribute__((unused)))
 312 {
 313   reshape_internal (ret, source, shape, pad, order, source_length);
 314 }
 315
 316
 317 extern void reshape_char4 (parray *, gfc_charlen_type, parray *, shape_type *,
 318                            parray *, shape_type *, gfc_charlen_type,
 319                            gfc_charlen_type);
 320 export_proto(reshape_char4);
 321
 322 void
 323 reshape_char4 (parray *ret, gfc_charlen_type ret_length __attribute__((unused)),
 324                parray *source, shape_type *shape, parray *pad,
 325                shape_type *order, gfc_charlen_type source_length,
 326                gfc_charlen_type pad_length __attribute__((unused)))
 327 {
 328   reshape_internal (ret, source, shape, pad, order,
 329                     source_length * sizeof (gfc_char4_t));
 330 }