libgfortran/generated/eoshift1_4.c

   1 /* Implementation of the EOSHIFT 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 Libgfortran 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., 59 Temple Place - Suite 330,
  29 Boston, MA 02111-1307, 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 const char zeros[16] =
  38   {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
  39
  40 extern void eoshift1_4 (const gfc_array_char *,
  41                                      const gfc_array_char *,
  42                                      const gfc_array_i4 *, const char *,
  43                                      const GFC_INTEGER_4 *);
  44 export_proto(eoshift1_4);
  45
  46 void
  47 eoshift1_4 (const gfc_array_char *ret,
  48                        const gfc_array_char *array,
  49                        const gfc_array_i4 *h, const char *pbound,
  50                        const GFC_INTEGER_4 *pwhich)
  51 {
  52   /* r.* indicates the return array.  */
  53   index_type rstride[GFC_MAX_DIMENSIONS - 1];
  54   index_type rstride0;
  55   index_type roffset;
  56   char *rptr;
  57   char *dest;
  58   /* s.* indicates the source array.  */
  59   index_type sstride[GFC_MAX_DIMENSIONS - 1];
  60   index_type sstride0;
  61   index_type soffset;
  62   const char *sptr;
  63   const char *src;
  64   /* h.* indicates the shift array.  */
  65   index_type hstride[GFC_MAX_DIMENSIONS - 1];
  66   index_type hstride0;
  67   const GFC_INTEGER_4 *hptr;
  68
  69   index_type count[GFC_MAX_DIMENSIONS - 1];
  70   index_type extent[GFC_MAX_DIMENSIONS - 1];
  71   index_type dim;
  72   index_type size;
  73   index_type len;
  74   index_type n;
  75   int which;
  76   GFC_INTEGER_4 sh;
  77   GFC_INTEGER_4 delta;
  78
  79   if (pwhich)
  80     which = *pwhich - 1;
  81   else
  82     which = 0;
  83
  84   if (!pbound)
  85     pbound = zeros;
  86
  87   size = GFC_DESCRIPTOR_SIZE (ret);
  88
  89   extent[0] = 1;
  90   count[0] = 0;
  91   size = GFC_DESCRIPTOR_SIZE (array);
  92   n = 0;
  93   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
  94     {
  95       if (dim == which)
  96         {
  97           roffset = ret->dim[dim].stride * size;
  98           if (roffset == 0)
  99             roffset = size;
 100           soffset = array->dim[dim].stride * size;
 101           if (soffset == 0)
 102             soffset = size;
 103           len = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 104         }
 105       else
 106         {
 107           count[n] = 0;
 108           extent[n] = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 109           rstride[n] = ret->dim[dim].stride * size;
 110           sstride[n] = array->dim[dim].stride * size;
 111
 112           hstride[n] = h->dim[n].stride;
 113           n++;
 114         }
 115     }
 116   if (sstride[0] == 0)
 117     sstride[0] = size;
 118   if (rstride[0] == 0)
 119     rstride[0] = size;
 120   if (hstride[0] == 0)
 121     hstride[0] = 1;
 122
 123   dim = GFC_DESCRIPTOR_RANK (array);
 124   rstride0 = rstride[0];
 125   sstride0 = sstride[0];
 126   hstride0 = hstride[0];
 127   rptr = ret->data;
 128   sptr = array->data;
 129   hptr = h->data;
 130
 131   while (rptr)
 132     {
 133       /* Do the shift for this dimension.  */
 134       sh = *hptr;
 135       delta = (sh >= 0) ? sh: -sh;
 136       if (sh > 0)
 137         {
 138           src = &sptr[delta * soffset];
 139           dest = rptr;
 140         }
 141       else
 142         {
 143           src = sptr;
 144           dest = &rptr[delta * roffset];
 145         }
 146       for (n = 0; n < len - delta; n++)
 147         {
 148           memcpy (dest, src, size);
 149           dest += roffset;
 150           src += soffset;
 151         }
 152       if (sh < 0)
 153         dest = rptr;
 154       n = delta;
 155
 156       while (n--)
 157         {
 158           memcpy (dest, pbound, size);
 159           dest += roffset;
 160         }
 161
 162       /* Advance to the next section.  */
 163       rptr += rstride0;
 164       sptr += sstride0;
 165       hptr += hstride0;
 166       count[0]++;
 167       n = 0;
 168       while (count[n] == extent[n])
 169         {
 170           /* When we get to the end of a dimension, reset it and increment
 171              the next dimension.  */
 172           count[n] = 0;
 173           /* We could precalculate these products, but this is a less
 174              frequently used path so proabably not worth it.  */
 175           rptr -= rstride[n] * extent[n];
 176           sptr -= sstride[n] * extent[n];
 177           hptr -= hstride[n] * extent[n];
 178           n++;
 179           if (n >= dim - 1)
 180             {
 181               /* Break out of the loop.  */
 182               rptr = NULL;
 183               break;
 184             }
 185           else
 186             {
 187               count[n]++;
 188               rptr += rstride[n];
 189               sptr += sstride[n];
 190               hptr += hstride[n];
 191             }
 192         }
 193     }
 194 }