libgfortran/intrinsics/spread_generic.c

   1 /* Generic implementation of the SPREAD intrinsic
   2    Copyright 2002, 2005 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       if (ret->dim[0].stride == 0)
 113         ret->dim[0].stride = 1;
 114
 115       for (n = 0; n < rrank; n++)
 116         {
 117           if (n == *along - 1)
 118             {
 119               rdelta = ret->dim[n].stride * size;
 120             }
 121           else
 122             {
 123               count[dim] = 0;
 124               extent[dim] = source->dim[dim].ubound + 1
 125                 - source->dim[dim].lbound;
 126               sstride[dim] = source->dim[dim].stride * size;
 127               rstride[dim] = ret->dim[n].stride * size;
 128               dim++;
 129             }
 130         }
 131       if (sstride[0] == 0)
 132         sstride[0] = size;
 133     }
 134   sstride0 = sstride[0];
 135   rstride0 = rstride[0];
 136   rptr = ret->data;
 137   sptr = source->data;
 138
 139   while (sptr)
 140     {
 141       /* Spread this element.  */
 142       dest = rptr;
 143       for (n = 0; n < ncopies; n++)
 144         {
 145           memcpy (dest, sptr, size);
 146           dest += rdelta;
 147         }
 148       /* Advance to the next element.  */
 149       sptr += sstride0;
 150       rptr += rstride0;
 151       count[0]++;
 152       n = 0;
 153       while (count[n] == extent[n])
 154         {
 155           /* When we get to the end of a dimension, reset it and increment
 156              the next dimension.  */
 157           count[n] = 0;
 158           /* We could precalculate these products, but this is a less
 159              frequently used path so probably not worth it.  */
 160           sptr -= sstride[n] * extent[n];
 161           rptr -= rstride[n] * extent[n];
 162           n++;
 163           if (n >= srank)
 164             {
 165               /* Break out of the loop.  */
 166               sptr = NULL;
 167               break;
 168             }
 169           else
 170             {
 171               count[n]++;
 172               sptr += sstride[n];
 173               rptr += rstride[n];
 174             }
 175         }
 176     }
 177 }
 178
 179 extern void spread (gfc_array_char *, const gfc_array_char *,
 180                     const index_type *, const index_type *);
 181 export_proto(spread);
 182
 183 void
 184 spread (gfc_array_char *ret, const gfc_array_char *source,
 185         const index_type *along, const index_type *pncopies)
 186 {
 187   spread_internal (ret, source, along, pncopies, GFC_DESCRIPTOR_SIZE (source));
 188 }
 189
 190 extern void spread_char (gfc_array_char *, GFC_INTEGER_4,
 191                          const gfc_array_char *, const index_type *,
 192                          const index_type *, GFC_INTEGER_4);
 193 export_proto(spread_char);
 194
 195 void
 196 spread_char (gfc_array_char *ret,
 197              GFC_INTEGER_4 ret_length __attribute__((unused)),
 198              const gfc_array_char *source, const index_type *along,
 199              const index_type *pncopies, GFC_INTEGER_4 source_length)
 200 {
 201   spread_internal (ret, source, along, pncopies, source_length);
 202 }