libgfortran/generated/cshift1_4.c

   1 /* Implementation of the CSHIFT intrinsic
   2    Copyright 2003 Free Software Foundation, Inc.
   3    Contributed by Feng Wang <wf_cs@yahoo.com>
   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., 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 void cshift1_4 (gfc_array_char * ret,
  38                            const gfc_array_char * array,
  39                            const gfc_array_i4 * h, const GFC_INTEGER_4 * pwhich);
  40 export_proto(cshift1_4);
  41
  42 void
  43 cshift1_4 (gfc_array_char * ret,
  44                       const gfc_array_char * array,
  45                       const gfc_array_i4 * h, const GFC_INTEGER_4 * pwhich)
  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   /* h.* indicates the  array.  */
  60   index_type hstride[GFC_MAX_DIMENSIONS];
  61   index_type hstride0;
  62   const GFC_INTEGER_4 *hptr;
  63
  64   index_type count[GFC_MAX_DIMENSIONS];
  65   index_type extent[GFC_MAX_DIMENSIONS];
  66   index_type dim;
  67   index_type size;
  68   index_type len;
  69   index_type n;
  70   int which;
  71   GFC_INTEGER_4 sh;
  72
  73   if (pwhich)
  74     which = *pwhich - 1;
  75   else
  76     which = 0;
  77
  78   if (which < 0 || (which + 1) > GFC_DESCRIPTOR_RANK (array))
  79     runtime_error ("Argument 'DIM' is out of range in call to 'CSHIFT'");
  80
  81   size = GFC_DESCRIPTOR_SIZE (ret);
  82
  83   if (ret->data == NULL)
  84     {
  85       int i;
  86
  87       ret->data = internal_malloc_size (size * size0 ((array_t *)array));
  88       ret->base = 0;
  89       ret->dtype = array->dtype;
  90       for (i = 0; i < GFC_DESCRIPTOR_RANK (array); i++)
  91         {
  92           ret->dim[i].lbound = 0;
  93           ret->dim[i].ubound = array->dim[i].ubound - array->dim[i].lbound;
  94
  95           if (i == 0)
  96             ret->dim[i].stride = 1;
  97           else
  98             ret->dim[i].stride = (ret->dim[i-1].ubound + 1) * ret->dim[i-1].stride;
  99         }
 100     }
 101
 102   extent[0] = 1;
 103   count[0] = 0;
 104   size = GFC_DESCRIPTOR_SIZE (array);
 105   n = 0;
 106
 107   /* Initialized for avoiding compiler warnings.  */
 108   roffset = size;
 109   soffset = size;
 110   len = 0;
 111
 112   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
 113     {
 114       if (dim == which)
 115         {
 116           roffset = ret->dim[dim].stride * size;
 117           if (roffset == 0)
 118             roffset = size;
 119           soffset = array->dim[dim].stride * size;
 120           if (soffset == 0)
 121             soffset = size;
 122           len = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 123         }
 124       else
 125         {
 126           count[n] = 0;
 127           extent[n] = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 128           rstride[n] = ret->dim[dim].stride * size;
 129           sstride[n] = array->dim[dim].stride * size;
 130
 131           hstride[n] = h->dim[n].stride;
 132           n++;
 133         }
 134     }
 135   if (sstride[0] == 0)
 136     sstride[0] = size;
 137   if (rstride[0] == 0)
 138     rstride[0] = size;
 139   if (hstride[0] == 0)
 140     hstride[0] = 1;
 141
 142   dim = GFC_DESCRIPTOR_RANK (array);
 143   rstride0 = rstride[0];
 144   sstride0 = sstride[0];
 145   hstride0 = hstride[0];
 146   rptr = ret->data;
 147   sptr = array->data;
 148   hptr = h->data;
 149
 150   while (rptr)
 151     {
 152       /* Do the  for this dimension.  */
 153       sh = *hptr;
 154       sh = (div (sh, len)).rem;
 155       if (sh < 0)
 156         sh += len;
 157
 158       src = &sptr[sh * soffset];
 159       dest = rptr;
 160
 161       for (n = 0; n < len; n++)
 162         {
 163           memcpy (dest, src, size);
 164           dest += roffset;
 165           if (n == len - sh - 1)
 166             src = sptr;
 167           else
 168             src += soffset;
 169         }
 170
 171       /* Advance to the next section.  */
 172       rptr += rstride0;
 173       sptr += sstride0;
 174       hptr += hstride0;
 175       count[0]++;
 176       n = 0;
 177       while (count[n] == extent[n])
 178         {
 179           /* When we get to the end of a dimension, reset it and increment
 180              the next dimension.  */
 181           count[n] = 0;
 182           /* We could precalculate these products, but this is a less
 183              frequently used path so proabably not worth it.  */
 184           rptr -= rstride[n] * extent[n];
 185           sptr -= sstride[n] * extent[n];
 186           hptr -= hstride[n] * extent[n];
 187           n++;
 188           if (n >= dim - 1)
 189             {
 190               /* Break out of the loop.  */
 191               rptr = NULL;
 192               break;
 193             }
 194           else
 195             {
 196               count[n]++;
 197               rptr += rstride[n];
 198               sptr += sstride[n];
 199               hptr += hstride[n];
 200             }
 201         }
 202     }
 203 }