libgfortran/m4/cshift1.m4

   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 Lesser General Public
   9 License as published by the Free Software Foundation; either
  10 version 2.1 of the License, or (at your option) any later version.
  11
  12 Ligbfor is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU Lesser General Public License for more details.
  16
  17 You should have received a copy of the GNU Lesser General Public
  18 License along with libgfor; see the file COPYING.LIB.  If not,
  19 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include <stdlib.h>
  24 #include <assert.h>
  25 #include <string.h>
  26 #include "libgfortran.h"'
  27 include(iparm.m4)dnl
  28
  29 void
  30 `__cshift1_'atype_kind (const gfc_array_char * ret, const gfc_array_char * array,
  31     const atype * h, const atype_name * pwhich)
  32 {
  33   /* r.* indicates the return array.  */
  34   index_type rstride[GFC_MAX_DIMENSIONS - 1];
  35   index_type rstride0;
  36   index_type roffset;
  37   char *rptr;
  38   char *dest;
  39   /* s.* indicates the source array.  */
  40   index_type sstride[GFC_MAX_DIMENSIONS - 1];
  41   index_type sstride0;
  42   index_type soffset;
  43   const char *sptr;
  44   const char *src;
  45 `  /* h.* indicates the shift array.  */'
  46   index_type hstride[GFC_MAX_DIMENSIONS - 1];
  47   index_type hstride0;
  48   const atype_name *hptr;
  49
  50   index_type count[GFC_MAX_DIMENSIONS - 1];
  51   index_type extent[GFC_MAX_DIMENSIONS - 1];
  52   index_type dim;
  53   index_type size;
  54   index_type len;
  55   index_type n;
  56   int which;
  57   atype_name sh;
  58
  59   if (pwhich)
  60     which = *pwhich - 1;
  61   else
  62     which = 0;
  63
  64   if (which < 0 || (which + 1) > GFC_DESCRIPTOR_RANK (array))
  65     runtime_error ("Argument 'DIM' is out of range in call to 'CSHIFT'");
  66
  67   size = GFC_DESCRIPTOR_SIZE (ret);
  68
  69   extent[0] = 1;
  70   count[0] = 0;
  71   size = GFC_DESCRIPTOR_SIZE (array);
  72   n = 0;
  73
  74 `/* Initialized for avoiding compiler warnings.  */'
  75   roffset = size;
  76   soffset = size;
  77   len = 0;
  78
  79   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
  80     {
  81       if (dim == which)
  82         {
  83           roffset = ret->dim[dim].stride * size;
  84           if (roffset == 0)
  85             roffset = size;
  86           soffset = array->dim[dim].stride * size;
  87           if (soffset == 0)
  88             soffset = size;
  89           len = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
  90         }
  91       else
  92         {
  93           count[n] = 0;
  94           extent[n] = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
  95           rstride[n] = ret->dim[dim].stride * size;
  96           sstride[n] = array->dim[dim].stride * size;
  97
  98           hstride[n] = h->dim[n].stride;
  99           n++;
 100         }
 101     }
 102   if (sstride[0] == 0)
 103     sstride[0] = size;
 104   if (rstride[0] == 0)
 105     rstride[0] = size;
 106   if (hstride[0] == 0)
 107     hstride[0] = 1;
 108
 109   dim = GFC_DESCRIPTOR_RANK (array);
 110   rstride0 = rstride[0];
 111   sstride0 = sstride[0];
 112   hstride0 = hstride[0];
 113   rptr = ret->data;
 114   sptr = array->data;
 115   hptr = h->data;
 116
 117   while (rptr)
 118     {
 119 `      /* Do the shift for this dimension.  */'
 120       sh = *hptr;
 121       sh = (div (sh, len)).rem;
 122       if (sh < 0)
 123         sh += len;
 124
 125       src = &sptr[sh * soffset];
 126       dest = rptr;
 127
 128       for (n = 0; n < len; n++)
 129         {
 130           memcpy (dest, src, size);
 131           dest += roffset;
 132           if (n == len - sh - 1)
 133             src = sptr;
 134           else
 135             src += soffset;
 136         }
 137
 138       /* Advance to the next section.  */
 139       rptr += rstride0;
 140       sptr += sstride0;
 141       hptr += hstride0;
 142       count[0]++;
 143       n = 0;
 144       while (count[n] == extent[n])
 145         {
 146           /* When we get to the end of a dimension, reset it and increment
 147              the next dimension.  */
 148           count[n] = 0;
 149           /* We could precalculate these products, but this is a less
 150              frequently used path so proabably not worth it.  */
 151           rptr -= rstride[n] * extent[n];
 152           sptr -= sstride[n] * extent[n];
 153           hptr -= hstride[n] * extent[n];
 154           n++;
 155           if (n >= dim - 1)
 156             {
 157               /* Break out of the loop.  */
 158               rptr = NULL;
 159               break;
 160             }
 161           else
 162             {
 163               count[n]++;
 164               rptr += rstride[n];
 165               sptr += sstride[n];
 166               hptr += hstride[n];
 167             }
 168         }
 169     }
 170 }
 171