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 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 include(iparm.m4)dnl
  37
  38 void cshift1_`'atype_kind (const gfc_array_char * ret,
  39                            const gfc_array_char * array,
  40                            const atype * h, const atype_name * pwhich);
  41 export_proto(cshift1_`'atype_kind);
  42
  43 void
  44 cshift1_`'atype_kind (const gfc_array_char * ret,
  45                       const gfc_array_char * array,
  46                       const atype * h, const atype_name * pwhich)
  47 {
  48   /* r.* indicates the return array.  */
  49   index_type rstride[GFC_MAX_DIMENSIONS - 1];
  50   index_type rstride0;
  51   index_type roffset;
  52   char *rptr;
  53   char *dest;
  54   /* s.* indicates the source array.  */
  55   index_type sstride[GFC_MAX_DIMENSIONS - 1];
  56   index_type sstride0;
  57   index_type soffset;
  58   const char *sptr;
  59   const char *src;
  60   /* h.* indicates the shift array.  */
  61   index_type hstride[GFC_MAX_DIMENSIONS - 1];
  62   index_type hstride0;
  63   const atype_name *hptr;
  64
  65   index_type count[GFC_MAX_DIMENSIONS - 1];
  66   index_type extent[GFC_MAX_DIMENSIONS - 1];
  67   index_type dim;
  68   index_type size;
  69   index_type len;
  70   index_type n;
  71   int which;
  72   atype_name sh;
  73
  74   if (pwhich)
  75     which = *pwhich - 1;
  76   else
  77     which = 0;
  78
  79   if (which < 0 || (which + 1) > GFC_DESCRIPTOR_RANK (array))
  80     runtime_error ("Argument 'DIM' is out of range in call to 'CSHIFT'");
  81
  82   size = GFC_DESCRIPTOR_SIZE (ret);
  83
  84   extent[0] = 1;
  85   count[0] = 0;
  86   size = GFC_DESCRIPTOR_SIZE (array);
  87   n = 0;
  88
  89   /* Initialized for avoiding compiler warnings.  */
  90   roffset = size;
  91   soffset = size;
  92   len = 0;
  93
  94   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
  95     {
  96       if (dim == which)
  97         {
  98           roffset = ret->dim[dim].stride * size;
  99           if (roffset == 0)
 100             roffset = size;
 101           soffset = array->dim[dim].stride * size;
 102           if (soffset == 0)
 103             soffset = size;
 104           len = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 105         }
 106       else
 107         {
 108           count[n] = 0;
 109           extent[n] = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 110           rstride[n] = ret->dim[dim].stride * size;
 111           sstride[n] = array->dim[dim].stride * size;
 112
 113           hstride[n] = h->dim[n].stride;
 114           n++;
 115         }
 116     }
 117   if (sstride[0] == 0)
 118     sstride[0] = size;
 119   if (rstride[0] == 0)
 120     rstride[0] = size;
 121   if (hstride[0] == 0)
 122     hstride[0] = 1;
 123
 124   dim = GFC_DESCRIPTOR_RANK (array);
 125   rstride0 = rstride[0];
 126   sstride0 = sstride[0];
 127   hstride0 = hstride[0];
 128   rptr = ret->data;
 129   sptr = array->data;
 130   hptr = h->data;
 131
 132   while (rptr)
 133     {
 134       /* Do the shift for this dimension.  */
 135       sh = *hptr;
 136       sh = (div (sh, len)).rem;
 137       if (sh < 0)
 138         sh += len;
 139
 140       src = &sptr[sh * soffset];
 141       dest = rptr;
 142
 143       for (n = 0; n < len; n++)
 144         {
 145           memcpy (dest, src, size);
 146           dest += roffset;
 147           if (n == len - sh - 1)
 148             src = sptr;
 149           else
 150             src += soffset;
 151         }
 152
 153       /* Advance to the next section.  */
 154       rptr += rstride0;
 155       sptr += sstride0;
 156       hptr += hstride0;
 157       count[0]++;
 158       n = 0;
 159       while (count[n] == extent[n])
 160         {
 161           /* When we get to the end of a dimension, reset it and increment
 162              the next dimension.  */
 163           count[n] = 0;
 164           /* We could precalculate these products, but this is a less
 165              frequently used path so proabably not worth it.  */
 166           rptr -= rstride[n] * extent[n];
 167           sptr -= sstride[n] * extent[n];
 168           hptr -= hstride[n] * extent[n];
 169           n++;
 170           if (n >= dim - 1)
 171             {
 172               /* Break out of the loop.  */
 173               rptr = NULL;
 174               break;
 175             }
 176           else
 177             {
 178               count[n]++;
 179               rptr += rstride[n];
 180               sptr += sstride[n];
 181               hptr += hstride[n];
 182             }
 183         }
 184     }
 185 }