libgfortran/intrinsics/spread_generic.c

   1 /* Generic implementation of the SPREAD intrinsic
   2    Copyright 2002, 2005, 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 <assert.h>
  34 #include <string.h>
  35
  36 static void
  37 spread_internal (gfc_array_char *ret, const gfc_array_char *source,
  38                  const index_type *along, const index_type *pncopies,
  39                  index_type size)
  40 {
  41   /* r.* indicates the return array.  */
  42   index_type rstride[GFC_MAX_DIMENSIONS];
  43   index_type rstride0;
  44   index_type rdelta = 0;
  45   index_type rrank;
  46   index_type rs;
  47   char *rptr;
  48   char *dest;
  49   /* s.* indicates the source array.  */
  50   index_type sstride[GFC_MAX_DIMENSIONS];
  51   index_type sstride0;
  52   index_type srank;
  53   const char *sptr;
  54
  55   index_type count[GFC_MAX_DIMENSIONS];
  56   index_type extent[GFC_MAX_DIMENSIONS];
  57   index_type n;
  58   index_type dim;
  59   index_type ncopies;
  60
  61   srank = GFC_DESCRIPTOR_RANK(source);
  62
  63   rrank = srank + 1;
  64   if (rrank > GFC_MAX_DIMENSIONS)
  65     runtime_error ("return rank too large in spread()");
  66
  67   if (*along > rrank)
  68       runtime_error ("dim outside of rank in spread()");
  69
  70   ncopies = *pncopies;
  71
  72   if (ret->data == NULL)
  73     {
  74       /* The front end has signalled that we need to populate the
  75          return array descriptor.  */
  76       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rrank;
  77       dim = 0;
  78       rs = 1;
  79       for (n = 0; n < rrank; n++)
  80         {
  81           ret->dim[n].stride = rs;
  82           ret->dim[n].lbound = 0;
  83           if (n == *along - 1)
  84             {
  85               ret->dim[n].ubound = ncopies - 1;
  86               rdelta = rs * size;
  87               rs *= ncopies;
  88             }
  89           else
  90             {
  91               count[dim] = 0;
  92               extent[dim] = source->dim[dim].ubound + 1
  93                 - source->dim[dim].lbound;
  94               sstride[dim] = source->dim[dim].stride * size;
  95               rstride[dim] = rs * size;
  96
  97               ret->dim[n].ubound = extent[dim]-1;
  98               rs *= extent[dim];
  99               dim++;
 100             }
 101         }
 102       ret->offset = 0;
 103       if (rs > 0)
 104         ret->data = internal_malloc_size (rs * size);
 105       else
 106         {
 107           ret->data = internal_malloc_size (1);
 108           return;
 109         }
 110     }
 111   else
 112     {
 113       dim = 0;
 114       if (GFC_DESCRIPTOR_RANK(ret) != rrank)
 115         runtime_error ("rank mismatch in spread()");
 116
 117       for (n = 0; n < rrank; n++)
 118         {
 119           if (n == *along - 1)
 120             {
 121               rdelta = ret->dim[n].stride * size;
 122             }
 123           else
 124             {
 125               count[dim] = 0;
 126               extent[dim] = source->dim[dim].ubound + 1
 127                 - source->dim[dim].lbound;
 128               sstride[dim] = source->dim[dim].stride * size;
 129               rstride[dim] = ret->dim[n].stride * size;
 130               dim++;
 131             }
 132         }
 133       if (sstride[0] == 0)
 134         sstride[0] = size;
 135     }
 136   sstride0 = sstride[0];
 137   rstride0 = rstride[0];
 138   rptr = ret->data;
 139   sptr = source->data;
 140
 141   while (sptr)
 142     {
 143       /* Spread this element.  */
 144       dest = rptr;
 145       for (n = 0; n < ncopies; n++)
 146         {
 147           memcpy (dest, sptr, size);
 148           dest += rdelta;
 149         }
 150       /* Advance to the next element.  */
 151       sptr += sstride0;
 152       rptr += rstride0;
 153       count[0]++;
 154       n = 0;
 155       while (count[n] == extent[n])
 156         {
 157           /* When we get to the end of a dimension, reset it and increment
 158              the next dimension.  */
 159           count[n] = 0;
 160           /* We could precalculate these products, but this is a less
 161              frequently used path so probably not worth it.  */
 162           sptr -= sstride[n] * extent[n];
 163           rptr -= rstride[n] * extent[n];
 164           n++;
 165           if (n >= srank)
 166             {
 167               /* Break out of the loop.  */
 168               sptr = NULL;
 169               break;
 170             }
 171           else
 172             {
 173               count[n]++;
 174               sptr += sstride[n];
 175               rptr += rstride[n];
 176             }
 177         }
 178     }
 179 }
 180
 181 /* This version of spread_internal treats the special case of a scalar
 182    source.  This is much simpler than the more general case above.  */
 183
 184 static void
 185 spread_internal_scalar (gfc_array_char *ret, const char *source,
 186                         const index_type *along, const index_type *pncopies,
 187                         index_type size)
 188 {
 189   int n;
 190   int ncopies = *pncopies;
 191   char * dest;
 192
 193   if (GFC_DESCRIPTOR_RANK (ret) != 1)
 194     runtime_error ("incorrect destination rank in spread()");
 195
 196   if (*along > 1)
 197     runtime_error ("dim outside of rank in spread()");
 198
 199   if (ret->data == NULL)
 200     {
 201       ret->data = internal_malloc_size (ncopies * size);
 202       ret->offset = 0;
 203       ret->dim[0].stride = 1;
 204       ret->dim[0].lbound = 0;
 205       ret->dim[0].ubound = ncopies - 1;
 206     }
 207   else
 208     {
 209       if (ncopies - 1 > (ret->dim[0].ubound - ret->dim[0].lbound)
 210                            / ret->dim[0].stride)
 211         runtime_error ("dim too large in spread()");
 212     }
 213
 214   for (n = 0; n < ncopies; n++)
 215     {
 216       dest = (char*)(ret->data + n*size*ret->dim[0].stride);
 217       memcpy (dest , source, size);
 218     }
 219 }
 220
 221 extern void spread (gfc_array_char *, const gfc_array_char *,
 222                     const index_type *, const index_type *);
 223 export_proto(spread);
 224
 225 void
 226 spread (gfc_array_char *ret, const gfc_array_char *source,
 227         const index_type *along, const index_type *pncopies)
 228 {
 229   spread_internal (ret, source, along, pncopies, GFC_DESCRIPTOR_SIZE (source));
 230 }
 231
 232 extern void spread_char (gfc_array_char *, GFC_INTEGER_4,
 233                          const gfc_array_char *, const index_type *,
 234                          const index_type *, GFC_INTEGER_4);
 235 export_proto(spread_char);
 236
 237 void
 238 spread_char (gfc_array_char *ret,
 239              GFC_INTEGER_4 ret_length __attribute__((unused)),
 240              const gfc_array_char *source, const index_type *along,
 241              const index_type *pncopies, GFC_INTEGER_4 source_length)
 242 {
 243   spread_internal (ret, source, along, pncopies, source_length);
 244 }
 245
 246 /* The following are the prototypes for the versions of spread with a
 247    scalar source.  */
 248
 249 extern void spread_scalar (gfc_array_char *, const char *,
 250                            const index_type *, const index_type *);
 251 export_proto(spread_scalar);
 252
 253 void
 254 spread_scalar (gfc_array_char *ret, const char *source,
 255                const index_type *along, const index_type *pncopies)
 256 {
 257   if (!ret->dtype)
 258     runtime_error ("return array missing descriptor in spread()");
 259   spread_internal_scalar (ret, source, along, pncopies, GFC_DESCRIPTOR_SIZE (ret));
 260 }
 261
 262
 263 extern void spread_char_scalar (gfc_array_char *, GFC_INTEGER_4,
 264                                 const char *, const index_type *,
 265                                 const index_type *, GFC_INTEGER_4);
 266 export_proto(spread_char_scalar);
 267
 268 void
 269 spread_char_scalar (gfc_array_char *ret,
 270                     GFC_INTEGER_4 ret_length __attribute__((unused)),
 271                     const char *source, const index_type *along,
 272                     const index_type *pncopies, GFC_INTEGER_4 source_length)
 273 {
 274   if (!ret->dtype)
 275     runtime_error ("return array missing descriptor in spread()");
 276   spread_internal_scalar (ret, source, along, pncopies, source_length);
 277 }
 278