libgfortran/generated/cshift0_r10.c

   1 /* Helper function for cshift functions.
   2    Copyright (C) 2008-2016 Free Software Foundation, Inc.
   3    Contributed by Thomas Koenig <tkoenig@gcc.gnu.org>
   4
   5 This file is part of the GNU Fortran 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 3 of the License, or (at your option) any later version.
  11
  12 Libgfortran 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 General Public License for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgfortran.h"
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30
  31 #if defined (HAVE_GFC_REAL_10)
  32
  33 void
  34 cshift0_r10 (gfc_array_r10 *ret, const gfc_array_r10 *array, ptrdiff_t shift,
  35                      int which)
  36 {
  37   /* r.* indicates the return array.  */
  38   index_type rstride[GFC_MAX_DIMENSIONS];
  39   index_type rstride0;
  40   index_type roffset;
  41   GFC_REAL_10 *rptr;
  42
  43   /* s.* indicates the source array.  */
  44   index_type sstride[GFC_MAX_DIMENSIONS];
  45   index_type sstride0;
  46   index_type soffset;
  47   const GFC_REAL_10 *sptr;
  48
  49   index_type count[GFC_MAX_DIMENSIONS];
  50   index_type extent[GFC_MAX_DIMENSIONS];
  51   index_type dim;
  52   index_type len;
  53   index_type n;
  54
  55   which = which - 1;
  56   sstride[0] = 0;
  57   rstride[0] = 0;
  58
  59   extent[0] = 1;
  60   count[0] = 0;
  61   n = 0;
  62   /* Initialized for avoiding compiler warnings.  */
  63   roffset = 1;
  64   soffset = 1;
  65   len = 0;
  66
  67   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
  68     {
  69       if (dim == which)
  70         {
  71           roffset = GFC_DESCRIPTOR_STRIDE(ret,dim);
  72           if (roffset == 0)
  73             roffset = 1;
  74           soffset = GFC_DESCRIPTOR_STRIDE(array,dim);
  75           if (soffset == 0)
  76             soffset = 1;
  77           len = GFC_DESCRIPTOR_EXTENT(array,dim);
  78         }
  79       else
  80         {
  81           count[n] = 0;
  82           extent[n] = GFC_DESCRIPTOR_EXTENT(array,dim);
  83           rstride[n] = GFC_DESCRIPTOR_STRIDE(ret,dim);
  84           sstride[n] = GFC_DESCRIPTOR_STRIDE(array,dim);
  85           n++;
  86         }
  87     }
  88   if (sstride[0] == 0)
  89     sstride[0] = 1;
  90   if (rstride[0] == 0)
  91     rstride[0] = 1;
  92
  93   dim = GFC_DESCRIPTOR_RANK (array);
  94   rstride0 = rstride[0];
  95   sstride0 = sstride[0];
  96   rptr = ret->base_addr;
  97   sptr = array->base_addr;
  98
  99   /* Avoid the costly modulo for trivially in-bound shifts.  */
 100   if (shift < 0 || shift >= len)
 101     {
 102       shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
 103       if (shift < 0)
 104         shift += len;
 105     }
 106
 107   while (rptr)
 108     {
 109       /* Do the shift for this dimension.  */
 110
 111       /* If elements are contiguous, perform the operation
 112          in two block moves.  */
 113       if (soffset == 1 && roffset == 1)
 114         {
 115           size_t len1 = shift * sizeof (GFC_REAL_10);
 116           size_t len2 = (len - shift) * sizeof (GFC_REAL_10);
 117           memcpy (rptr, sptr + shift, len2);
 118           memcpy (rptr + (len - shift), sptr, len1);
 119         }
 120       else
 121         {
 122           /* Otherwise, we will have to perform the copy one element at
 123              a time.  */
 124           GFC_REAL_10 *dest = rptr;
 125           const GFC_REAL_10 *src = &sptr[shift * soffset];
 126
 127           for (n = 0; n < len - shift; n++)
 128             {
 129               *dest = *src;
 130               dest += roffset;
 131               src += soffset;
 132             }
 133           for (src = sptr, n = 0; n < shift; n++)
 134             {
 135               *dest = *src;
 136               dest += roffset;
 137               src += soffset;
 138             }
 139         }
 140
 141       /* Advance to the next section.  */
 142       rptr += rstride0;
 143       sptr += sstride0;
 144       count[0]++;
 145       n = 0;
 146       while (count[n] == extent[n])
 147         {
 148           /* When we get to the end of a dimension, reset it and increment
 149              the next dimension.  */
 150           count[n] = 0;
 151           /* We could precalculate these products, but this is a less
 152              frequently used path so probably not worth it.  */
 153           rptr -= rstride[n] * extent[n];
 154           sptr -= sstride[n] * extent[n];
 155           n++;
 156           if (n >= dim - 1)
 157             {
 158               /* Break out of the loop.  */
 159               rptr = NULL;
 160               break;
 161             }
 162           else
 163             {
 164               count[n]++;
 165               rptr += rstride[n];
 166               sptr += sstride[n];
 167             }
 168         }
 169     }
 170
 171   return;
 172 }
 173
 174 #endif