libgfortran/intrinsics/spread_generic.c

   1 /* Generic implementation of the SPREAD intrinsic
   2    Copyright 2002, 2005, 2006 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 <assert.h>
  34 #include <string.h>
  35 #include "libgfortran.h"
  36
  37 static void
  38 spread_internal (gfc_array_char *ret, const gfc_array_char *source,
  39                  const index_type *along, const index_type *pncopies,
  40                  index_type size)
  41 {
  42   /* r.* indicates the return array.  */
  43   index_type rstride[GFC_MAX_DIMENSIONS];
  44   index_type rstride0;
  45   index_type rdelta = 0;
  46   index_type rrank;
  47   index_type rs;
  48   char *rptr;
  49   char *dest;
  50   /* s.* indicates the source array.  */
  51   index_type sstride[GFC_MAX_DIMENSIONS];
  52   index_type sstride0;
  53   index_type srank;
  54   const char *sptr;
  55
  56   index_type count[GFC_MAX_DIMENSIONS];
  57   index_type extent[GFC_MAX_DIMENSIONS];
  58   index_type n;
  59   index_type dim;
  60   index_type ncopies;
  61
  62   srank = GFC_DESCRIPTOR_RANK(source);
  63
  64   rrank = srank + 1;
  65   if (rrank > GFC_MAX_DIMENSIONS)
  66     runtime_error ("return rank too large in spread()");
  67
  68   if (*along > rrank)
  69       runtime_error ("dim outside of rank in spread()");
  70
  71   ncopies = *pncopies;
  72
  73   if (ret->data == NULL)
  74     {
  75       /* The front end has signalled that we need to populate the
  76          return array descriptor.  */
  77       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rrank;
  78       dim = 0;
  79       rs = 1;
  80       for (n = 0; n < rrank; n++)
  81         {
  82           ret->dim[n].stride = rs;
  83           ret->dim[n].lbound = 0;
  84           if (n == *along - 1)
  85             {
  86               ret->dim[n].ubound = ncopies - 1;
  87               rdelta = rs * size;
  88               rs *= ncopies;
  89             }
  90           else
  91             {
  92               count[dim] = 0;
  93               extent[dim] = source->dim[dim].ubound + 1
  94                 - source->dim[dim].lbound;
  95               sstride[dim] = source->dim[dim].stride * size;
  96               rstride[dim] = rs * size;
  97
  98               ret->dim[n].ubound = extent[dim]-1;
  99               rs *= extent[dim];
 100               dim++;
 101             }
 102         }
 103       ret->offset = 0;
 104       ret->data = internal_malloc_size (rs * size);
 105     }
 106   else
 107     {
 108       dim = 0;
 109       if (GFC_DESCRIPTOR_RANK(ret) != rrank)
 110         runtime_error ("rank mismatch in spread()");
 111
 112       for (n = 0; n < rrank; n++)
 113         {
 114           if (n == *along - 1)
 115             {
 116               rdelta = ret->dim[n].stride * size;
 117             }
 118           else
 119             {
 120               count[dim] = 0;
 121               extent[dim] = source->dim[dim].ubound + 1
 122                 - source->dim[dim].lbound;
 123               sstride[dim] = source->dim[dim].stride * size;
 124               rstride[dim] = ret->dim[n].stride * size;
 125               dim++;
 126             }
 127         }
 128       if (sstride[0] == 0)
 129         sstride[0] = size;
 130     }
 131   sstride0 = sstride[0];
 132   rstride0 = rstride[0];
 133   rptr = ret->data;
 134   sptr = source->data;
 135
 136   while (sptr)
 137     {
 138       /* Spread this element.  */
 139       dest = rptr;
 140       for (n = 0; n < ncopies; n++)
 141         {
 142           memcpy (dest, sptr, size);
 143           dest += rdelta;
 144         }
 145       /* Advance to the next element.  */
 146       sptr += sstride0;
 147       rptr += rstride0;
 148       count[0]++;
 149       n = 0;
 150       while (count[n] == extent[n])
 151         {
 152           /* When we get to the end of a dimension, reset it and increment
 153              the next dimension.  */
 154           count[n] = 0;
 155           /* We could precalculate these products, but this is a less
 156              frequently used path so probably not worth it.  */
 157           sptr -= sstride[n] * extent[n];
 158           rptr -= rstride[n] * extent[n];
 159           n++;
 160           if (n >= srank)
 161             {
 162               /* Break out of the loop.  */
 163               sptr = NULL;
 164               break;
 165             }
 166           else
 167             {
 168               count[n]++;
 169               sptr += sstride[n];
 170               rptr += rstride[n];
 171             }
 172         }
 173     }
 174 }
 175
 176 /* This version of spread_internal treats the special case of a scalar
 177    source.  This is much simpler than the more general case above.  */
 178
 179 static void
 180 spread_internal_scalar (gfc_array_char *ret, const char *source,
 181                         const index_type *along, const index_type *pncopies,
 182                         index_type size)
 183 {
 184   int n;
 185   int ncopies = *pncopies;
 186   char * dest;
 187
 188   if (GFC_DESCRIPTOR_RANK (ret) != 1)
 189     runtime_error ("incorrect destination rank in spread()");
 190
 191   if (*along > 1)
 192     runtime_error ("dim outside of rank in spread()");
 193
 194   if (ret->data == NULL)
 195     {
 196       ret->data = internal_malloc_size (ncopies * size);
 197       ret->offset = 0;
 198       ret->dim[0].stride = 1;
 199       ret->dim[0].lbound = 0;
 200       ret->dim[0].ubound = ncopies - 1;
 201     }
 202   else
 203     {
 204       if (ncopies - 1 > (ret->dim[0].ubound - ret->dim[0].lbound)
 205                            / ret->dim[0].stride)
 206         runtime_error ("dim too large in spread()");
 207     }
 208
 209   for (n = 0; n < ncopies; n++)
 210     {
 211       dest = (char*)(ret->data + n*size*ret->dim[0].stride);
 212       memcpy (dest , source, size);
 213     }
 214 }
 215
 216 extern void spread (gfc_array_char *, const gfc_array_char *,
 217                     const index_type *, const index_type *);
 218 export_proto(spread);
 219
 220 void
 221 spread (gfc_array_char *ret, const gfc_array_char *source,
 222         const index_type *along, const index_type *pncopies)
 223 {
 224   spread_internal (ret, source, along, pncopies, GFC_DESCRIPTOR_SIZE (source));
 225 }
 226
 227 extern void spread_char (gfc_array_char *, GFC_INTEGER_4,
 228                          const gfc_array_char *, const index_type *,
 229                          const index_type *, GFC_INTEGER_4);
 230 export_proto(spread_char);
 231
 232 void
 233 spread_char (gfc_array_char *ret,
 234              GFC_INTEGER_4 ret_length __attribute__((unused)),
 235              const gfc_array_char *source, const index_type *along,
 236              const index_type *pncopies, GFC_INTEGER_4 source_length)
 237 {
 238   spread_internal (ret, source, along, pncopies, source_length);
 239 }
 240
 241 /* The following are the prototypes for the versions of spread with a
 242    scalar source.  */
 243
 244 extern void spread_scalar (gfc_array_char *, const char *,
 245                            const index_type *, const index_type *);
 246 export_proto(spread_scalar);
 247
 248 void
 249 spread_scalar (gfc_array_char *ret, const char *source,
 250                const index_type *along, const index_type *pncopies)
 251 {
 252   if (!ret->dtype)
 253     runtime_error ("return array missing descriptor in spread()");
 254   spread_internal_scalar (ret, source, along, pncopies, GFC_DESCRIPTOR_SIZE (ret));
 255 }
 256
 257
 258 extern void spread_char_scalar (gfc_array_char *, GFC_INTEGER_4,
 259                                 const char *, const index_type *,
 260                                 const index_type *, GFC_INTEGER_4);
 261 export_proto(spread_char_scalar);
 262
 263 void
 264 spread_char_scalar (gfc_array_char *ret,
 265                     GFC_INTEGER_4 ret_length __attribute__((unused)),
 266                     const char *source, const index_type *along,
 267                     const index_type *pncopies, GFC_INTEGER_4 source_length)
 268 {
 269   if (!ret->dtype)
 270     runtime_error ("return array missing descriptor in spread()");
 271   spread_internal_scalar (ret, source, along, pncopies, source_length);
 272 }
 273