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 (const 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 (const 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 - 1];
  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 - 1];
  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 - 1];
  61   index_type hstride0;
  62   const GFC_INTEGER_4 *hptr;
  63
  64   index_type count[GFC_MAX_DIMENSIONS - 1];
  65   index_type extent[GFC_MAX_DIMENSIONS - 1];
  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   extent[0] = 1;
  84   count[0] = 0;
  85   size = GFC_DESCRIPTOR_SIZE (array);
  86   n = 0;
  87
  88   /* Initialized for avoiding compiler warnings.  */
  89   roffset = size;
  90   soffset = size;
  91   len = 0;
  92
  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  for this dimension.  */
 134       sh = *hptr;
 135       sh = (div (sh, len)).rem;
 136       if (sh < 0)
 137         sh += len;
 138
 139       src = &sptr[sh * soffset];
 140       dest = rptr;
 141
 142       for (n = 0; n < len; n++)
 143         {
 144           memcpy (dest, src, size);
 145           dest += roffset;
 146           if (n == len - sh - 1)
 147             src = sptr;
 148           else
 149             src += soffset;
 150         }
 151
 152       /* Advance to the next section.  */
 153       rptr += rstride0;
 154       sptr += sstride0;
 155       hptr += hstride0;
 156       count[0]++;
 157       n = 0;
 158       while (count[n] == extent[n])
 159         {
 160           /* When we get to the end of a dimension, reset it and increment
 161              the next dimension.  */
 162           count[n] = 0;
 163           /* We could precalculate these products, but this is a less
 164              frequently used path so proabably not worth it.  */
 165           rptr -= rstride[n] * extent[n];
 166           sptr -= sstride[n] * extent[n];
 167           hptr -= hstride[n] * extent[n];
 168           n++;
 169           if (n >= dim - 1)
 170             {
 171               /* Break out of the loop.  */
 172               rptr = NULL;
 173               break;
 174             }
 175           else
 176             {
 177               count[n]++;
 178               rptr += rstride[n];
 179               sptr += sstride[n];
 180               hptr += hstride[n];
 181             }
 182         }
 183     }
 184 }