libgfortran/intrinsics/eoshift0.c

   1 /* Generic implementation of the EOSHIFT 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 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 /* TODO: make this work for large shifts when
  41    sizeof(int) < sizeof (index_type).  */
  42
  43 static void
  44 eoshift0 (gfc_array_char * ret, const gfc_array_char * array,
  45           int shift, const char * pbound, int which)
  46 {
  47   /* r.* indicates the return array.  */
  48   index_type rstride[GFC_MAX_DIMENSIONS];
  49   index_type rstride0;
  50   index_type roffset;
  51   char *rptr;
  52   char *dest;
  53   /* s.* indicates the source array.  */
  54   index_type sstride[GFC_MAX_DIMENSIONS];
  55   index_type sstride0;
  56   index_type soffset;
  57   const char *sptr;
  58   const char *src;
  59
  60   index_type count[GFC_MAX_DIMENSIONS];
  61   index_type extent[GFC_MAX_DIMENSIONS];
  62   index_type dim;
  63   index_type size;
  64   index_type len;
  65   index_type n;
  66
  67   /* The compiler cannot figure out that these are set, initialize
  68      them to avoid warnings.  */
  69   len = 0;
  70   soffset = 0;
  71   roffset = 0;
  72
  73   if (!pbound)
  74     pbound = zeros;
  75
  76   size = GFC_DESCRIPTOR_SIZE (ret);
  77
  78   if (ret->data == NULL)
  79     {
  80       int i;
  81
  82       ret->data = internal_malloc_size (size * size0 ((array_t *)array));
  83       ret->base = 0;
  84       ret->dtype = array->dtype;
  85       for (i = 0; i < GFC_DESCRIPTOR_RANK (array); i++)
  86         {
  87           ret->dim[i].lbound = 0;
  88           ret->dim[i].ubound = array->dim[i].ubound - array->dim[i].lbound;
  89
  90           if (i == 0)
  91             ret->dim[i].stride = 1;
  92           else
  93             ret->dim[i].stride = (ret->dim[i-1].ubound + 1) * ret->dim[i-1].stride;
  94         }
  95     }
  96
  97   which = which - 1;
  98
  99   extent[0] = 1;
 100   count[0] = 0;
 101   size = GFC_DESCRIPTOR_SIZE (array);
 102   n = 0;
 103   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
 104     {
 105       if (dim == which)
 106         {
 107           roffset = ret->dim[dim].stride * size;
 108           if (roffset == 0)
 109             roffset = size;
 110           soffset = array->dim[dim].stride * size;
 111           if (soffset == 0)
 112             soffset = size;
 113           len = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 114         }
 115       else
 116         {
 117           count[n] = 0;
 118           extent[n] = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 119           rstride[n] = ret->dim[dim].stride * size;
 120           sstride[n] = array->dim[dim].stride * size;
 121           n++;
 122         }
 123     }
 124   if (sstride[0] == 0)
 125     sstride[0] = size;
 126   if (rstride[0] == 0)
 127     rstride[0] = size;
 128
 129   dim = GFC_DESCRIPTOR_RANK (array);
 130   rstride0 = rstride[0];
 131   sstride0 = sstride[0];
 132   rptr = ret->data;
 133   sptr = array->data;
 134
 135   if ((shift >= 0 ? shift : -shift) > len)
 136     {
 137       shift = len;
 138       len = 0;
 139     }
 140   else
 141     {
 142       if (shift > 0)
 143         len = len - shift;
 144       else
 145         len = len + shift;
 146     }
 147
 148   while (rptr)
 149     {
 150       /* Do the shift for this dimension.  */
 151       if (shift > 0)
 152         {
 153           src = &sptr[shift * soffset];
 154           dest = rptr;
 155         }
 156       else
 157         {
 158           src = sptr;
 159           dest = &rptr[-shift * roffset];
 160         }
 161       for (n = 0; n < len; n++)
 162         {
 163           memcpy (dest, src, size);
 164           dest += roffset;
 165           src += soffset;
 166         }
 167       if (shift >= 0)
 168         {
 169           n = shift;
 170         }
 171       else
 172         {
 173           dest = rptr;
 174           n = -shift;
 175         }
 176
 177       while (n--)
 178         {
 179           memcpy (dest, pbound, size);
 180           dest += roffset;
 181         }
 182
 183       /* Advance to the next section.  */
 184       rptr += rstride0;
 185       sptr += sstride0;
 186       count[0]++;
 187       n = 0;
 188       while (count[n] == extent[n])
 189         {
 190           /* When we get to the end of a dimension, reset it and increment
 191              the next dimension.  */
 192           count[n] = 0;
 193           /* We could precalculate these products, but this is a less
 194              frequently used path so proabably not worth it.  */
 195           rptr -= rstride[n] * extent[n];
 196           sptr -= sstride[n] * extent[n];
 197           n++;
 198           if (n >= dim - 1)
 199             {
 200               /* Break out of the loop.  */
 201               rptr = NULL;
 202               break;
 203             }
 204           else
 205             {
 206               count[n]++;
 207               rptr += rstride[n];
 208               sptr += sstride[n];
 209             }
 210         }
 211     }
 212 }
 213
 214
 215 extern void eoshift0_1 (gfc_array_char *, const gfc_array_char *,
 216                         const GFC_INTEGER_1 *, const char *,
 217                         const GFC_INTEGER_1 *);
 218 export_proto(eoshift0_1);
 219
 220 void
 221 eoshift0_1 (gfc_array_char *ret, const gfc_array_char *array,
 222             const GFC_INTEGER_1 *pshift, const char *pbound,
 223             const GFC_INTEGER_1 *pdim)
 224 {
 225   eoshift0 (ret, array, *pshift, pbound, pdim ? *pdim : 1);
 226 }
 227
 228
 229 extern void eoshift0_2 (gfc_array_char *, const gfc_array_char *,
 230                         const GFC_INTEGER_2 *, const char *,
 231                         const GFC_INTEGER_2 *);
 232 export_proto(eoshift0_2);
 233
 234 void
 235 eoshift0_2 (gfc_array_char *ret, const gfc_array_char *array,
 236             const GFC_INTEGER_2 *pshift, const char *pbound,
 237             const GFC_INTEGER_2 *pdim)
 238 {
 239   eoshift0 (ret, array, *pshift, pbound, pdim ? *pdim : 1);
 240 }
 241
 242
 243 extern void eoshift0_4 (gfc_array_char *, const gfc_array_char *,
 244                         const GFC_INTEGER_4 *, const char *,
 245                         const GFC_INTEGER_4 *);
 246 export_proto(eoshift0_4);
 247
 248 void
 249 eoshift0_4 (gfc_array_char *ret, const gfc_array_char *array,
 250             const GFC_INTEGER_4 *pshift, const char *pbound,
 251             const GFC_INTEGER_4 *pdim)
 252 {
 253   eoshift0 (ret, array, *pshift, pbound, pdim ? *pdim : 1);
 254 }
 255
 256
 257 extern void eoshift0_8 (gfc_array_char *, const gfc_array_char *,
 258                         const GFC_INTEGER_8 *, const char *,
 259                         const GFC_INTEGER_8 *);
 260 export_proto(eoshift0_8);
 261
 262 void
 263 eoshift0_8 (gfc_array_char *ret, const gfc_array_char *array,
 264             const GFC_INTEGER_8 *pshift, const char *pbound,
 265             const GFC_INTEGER_8 *pdim)
 266 {
 267   eoshift0 (ret, array, *pshift, pbound, pdim ? *pdim : 1);
 268 }