libgfortran/intrinsics/reshape_generic.c

   1 /* Generic implementation of the RESHAPE intrinsic
   2    Copyright 2002 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 "config.h"
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <assert.h>
  35 #include "libgfortran.h"
  36
  37 typedef GFC_ARRAY_DESCRIPTOR(1, index_type) shape_type;
  38 typedef GFC_ARRAY_DESCRIPTOR(GFC_MAX_DIMENSIONS, char) parray;
  39
  40 /* The shape parameter is ignored. We can currently deduce the shape from the
  41    return array.  */
  42
  43 static void
  44 reshape_internal (parray *ret, parray *source, shape_type *shape,
  45                   parray *pad, shape_type *order, index_type size)
  46 {
  47   /* r.* indicates the return array.  */
  48   index_type rcount[GFC_MAX_DIMENSIONS];
  49   index_type rextent[GFC_MAX_DIMENSIONS];
  50   index_type rstride[GFC_MAX_DIMENSIONS];
  51   index_type rstride0;
  52   index_type rdim;
  53   index_type rsize;
  54   index_type rs;
  55   index_type rex;
  56   char *rptr;
  57   /* s.* indicates the source array.  */
  58   index_type scount[GFC_MAX_DIMENSIONS];
  59   index_type sextent[GFC_MAX_DIMENSIONS];
  60   index_type sstride[GFC_MAX_DIMENSIONS];
  61   index_type sstride0;
  62   index_type sdim;
  63   index_type ssize;
  64   const char *sptr;
  65   /* p.* indicates the pad array.  */
  66   index_type pcount[GFC_MAX_DIMENSIONS];
  67   index_type pextent[GFC_MAX_DIMENSIONS];
  68   index_type pstride[GFC_MAX_DIMENSIONS];
  69   index_type pdim;
  70   index_type psize;
  71   const char *pptr;
  72
  73   const char *src;
  74   int n;
  75   int dim;
  76
  77   if (source->dim[0].stride == 0)
  78     source->dim[0].stride = 1;
  79   if (shape->dim[0].stride == 0)
  80     shape->dim[0].stride = 1;
  81   if (pad && pad->dim[0].stride == 0)
  82     pad->dim[0].stride = 1;
  83   if (order && order->dim[0].stride == 0)
  84     order->dim[0].stride = 1;
  85
  86   if (ret->data == NULL)
  87     {
  88       rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
  89       rs = 1;
  90       for (n=0; n < rdim; n++)
  91         {
  92           ret->dim[n].lbound = 0;
  93           rex = shape->data[n * shape->dim[0].stride];
  94           ret->dim[n].ubound =  rex - 1;
  95           ret->dim[n].stride = rs;
  96           rs *= rex;
  97         }
  98       ret->offset = 0;
  99       ret->data = internal_malloc_size ( rs * size );
 100       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
 101     }
 102   else
 103     {
 104       rdim = GFC_DESCRIPTOR_RANK (ret);
 105       if (ret->dim[0].stride == 0)
 106         ret->dim[0].stride = 1;
 107     }
 108
 109   rsize = 1;
 110   for (n = 0; n < rdim; n++)
 111     {
 112       if (order)
 113         dim = order->data[n * order->dim[0].stride] - 1;
 114       else
 115         dim = n;
 116
 117       rcount[n] = 0;
 118       rstride[n] = ret->dim[dim].stride;
 119       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
 120
 121       if (rextent[n] != shape->data[dim * shape->dim[0].stride])
 122         runtime_error ("shape and target do not conform");
 123
 124       if (rsize == rstride[n])
 125         rsize *= rextent[n];
 126       else
 127         rsize = 0;
 128       if (rextent[n] <= 0)
 129         return;
 130     }
 131
 132   sdim = GFC_DESCRIPTOR_RANK (source);
 133   ssize = 1;
 134   for (n = 0; n < sdim; n++)
 135     {
 136       scount[n] = 0;
 137       sstride[n] = source->dim[n].stride;
 138       sextent[n] = source->dim[n].ubound + 1 - source->dim[n].lbound;
 139       if (sextent[n] <= 0)
 140         abort ();
 141
 142       if (ssize == sstride[n])
 143         ssize *= sextent[n];
 144       else
 145         ssize = 0;
 146     }
 147
 148   if (pad)
 149     {
 150       pdim = GFC_DESCRIPTOR_RANK (pad);
 151       psize = 1;
 152       for (n = 0; n < pdim; n++)
 153         {
 154           pcount[n] = 0;
 155           pstride[n] = pad->dim[n].stride;
 156           pextent[n] = pad->dim[n].ubound + 1 - pad->dim[n].lbound;
 157           if (pextent[n] <= 0)
 158             abort ();
 159           if (psize == pstride[n])
 160             psize *= pextent[n];
 161           else
 162             psize = 0;
 163         }
 164       pptr = pad->data;
 165     }
 166   else
 167     {
 168       pdim = 0;
 169       psize = 1;
 170       pptr = NULL;
 171     }
 172
 173   if (rsize != 0 && ssize != 0 && psize != 0)
 174     {
 175       rsize *= size;
 176       ssize *= size;
 177       psize *= size;
 178       reshape_packed (ret->data, rsize, source->data, ssize,
 179                       pad ? pad->data : NULL, psize);
 180       return;
 181     }
 182   rptr = ret->data;
 183   src = sptr = source->data;
 184   rstride0 = rstride[0] * size;
 185   sstride0 = sstride[0] * size;
 186
 187   while (rptr)
 188     {
 189       /* Select between the source and pad arrays.  */
 190       memcpy(rptr, src, size);
 191       /* Advance to the next element.  */
 192       rptr += rstride0;
 193       src += sstride0;
 194       rcount[0]++;
 195       scount[0]++;
 196       /* Advance to the next destination element.  */
 197       n = 0;
 198       while (rcount[n] == rextent[n])
 199         {
 200           /* When we get to the end of a dimension, reset it and increment
 201              the next dimension.  */
 202           rcount[n] = 0;
 203           /* We could precalculate these products, but this is a less
 204              frequently used path so proabably not worth it.  */
 205           rptr -= rstride[n] * rextent[n] * size;
 206           n++;
 207           if (n == rdim)
 208             {
 209               /* Break out of the loop.  */
 210               rptr = NULL;
 211               break;
 212             }
 213           else
 214             {
 215               rcount[n]++;
 216               rptr += rstride[n] * size;
 217             }
 218         }
 219       /* Advance to the next source element.  */
 220       n = 0;
 221       while (scount[n] == sextent[n])
 222         {
 223           /* When we get to the end of a dimension, reset it and increment
 224              the next dimension.  */
 225           scount[n] = 0;
 226           /* We could precalculate these products, but this is a less
 227              frequently used path so proabably not worth it.  */
 228           src -= sstride[n] * sextent[n] * size;
 229           n++;
 230           if (n == sdim)
 231             {
 232               if (sptr && pad)
 233                 {
 234                   /* Switch to the pad array.  */
 235                   sptr = NULL;
 236                   sdim = pdim;
 237                   for (dim = 0; dim < pdim; dim++)
 238                     {
 239                       scount[dim] = pcount[dim];
 240                       sextent[dim] = pextent[dim];
 241                       sstride[dim] = pstride[dim];
 242                       sstride0 = sstride[0] * size;
 243                     }
 244                 }
 245               /* We now start again from the beginning of the pad array.  */
 246               src = pptr;
 247               break;
 248             }
 249           else
 250             {
 251               scount[n]++;
 252               sptr += sstride[n] * size;
 253             }
 254         }
 255     }
 256 }
 257
 258 extern void reshape (parray *, parray *, shape_type *, parray *, shape_type *);
 259 export_proto(reshape);
 260
 261 void
 262 reshape (parray *ret, parray *source, shape_type *shape, parray *pad,
 263          shape_type *order)
 264 {
 265   reshape_internal (ret, source, shape, pad, order,
 266                     GFC_DESCRIPTOR_SIZE (source));
 267 }
 268
 269 extern void reshape_char (parray *, GFC_INTEGER_4, parray *, shape_type *,
 270                           parray *, shape_type *, GFC_INTEGER_4,
 271                           GFC_INTEGER_4);
 272 export_proto(reshape_char);
 273
 274 void
 275 reshape_char (parray *ret, GFC_INTEGER_4 ret_length __attribute__((unused)),
 276               parray *source, shape_type *shape, parray *pad,
 277               shape_type *order, GFC_INTEGER_4 source_length,
 278               GFC_INTEGER_4 pad_length __attribute__((unused)))
 279 {
 280   reshape_internal (ret, source, shape, pad, order, source_length);
 281 }