libgfortran/generated/cshift1_4_r4.c

   1 /* Implementation of the CSHIFT intrinsic.
   2    Copyright (C) 2017-2018 Free Software Foundation, Inc.
   3    Contributed by Thomas Koenig <tkoenig@gcc.gnu.org>
   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 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 <string.h>
  28
  29 #if defined (HAVE_GFC_REAL_4) && defined (HAVE_GFC_INTEGER_4)
  30
  31 void
  32 cshift1_4_r4 (gfc_array_r4 * const restrict ret,
  33                 const gfc_array_r4 * const restrict array,
  34                 const gfc_array_i4 * const restrict h,
  35                 const GFC_INTEGER_4 * const restrict pwhich)
  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_4 *rptr;
  42   GFC_REAL_4 *dest;
  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_4 *sptr;
  48   const GFC_REAL_4 *src;
  49   /* h.* indicates the shift array.  */
  50   index_type hstride[GFC_MAX_DIMENSIONS];
  51   index_type hstride0;
  52   const GFC_INTEGER_4 *hptr;
  53
  54   index_type count[GFC_MAX_DIMENSIONS];
  55   index_type extent[GFC_MAX_DIMENSIONS];
  56   index_type rs_ex[GFC_MAX_DIMENSIONS];
  57   index_type ss_ex[GFC_MAX_DIMENSIONS];
  58   index_type hs_ex[GFC_MAX_DIMENSIONS];
  59
  60   index_type dim;
  61   index_type len;
  62   index_type n;
  63   int which;
  64   GFC_INTEGER_4 sh;
  65
  66   /* Bounds checking etc is already done by the caller.  */
  67
  68   if (pwhich)
  69     which = *pwhich - 1;
  70   else
  71     which = 0;
  72
  73   extent[0] = 1;
  74   count[0] = 0;
  75   n = 0;
  76
  77   /* Initialized for avoiding compiler warnings.  */
  78   roffset = 1;
  79   soffset = 1;
  80   len = 0;
  81
  82   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
  83     {
  84       if (dim == which)
  85         {
  86           roffset = GFC_DESCRIPTOR_STRIDE(ret,dim);
  87           if (roffset == 0)
  88             roffset = 1;
  89           soffset = GFC_DESCRIPTOR_STRIDE(array,dim);
  90           if (soffset == 0)
  91             soffset = 1;
  92           len = GFC_DESCRIPTOR_EXTENT(array,dim);
  93         }
  94       else
  95         {
  96           count[n] = 0;
  97           extent[n] = GFC_DESCRIPTOR_EXTENT(array,dim);
  98           rstride[n] = GFC_DESCRIPTOR_STRIDE(ret,dim);
  99           sstride[n] = GFC_DESCRIPTOR_STRIDE(array,dim);
 100           hstride[n] = GFC_DESCRIPTOR_STRIDE(h,n);
 101           rs_ex[n] = rstride[n] * extent[n];
 102           ss_ex[n] = sstride[n] * extent[n];
 103           hs_ex[n] = hstride[n] * extent[n];
 104           n++;
 105         }
 106     }
 107   if (sstride[0] == 0)
 108     sstride[0] = 1;
 109   if (rstride[0] == 0)
 110     rstride[0] = 1;
 111   if (hstride[0] == 0)
 112     hstride[0] = 1;
 113
 114   dim = GFC_DESCRIPTOR_RANK (array);
 115   rstride0 = rstride[0];
 116   sstride0 = sstride[0];
 117   hstride0 = hstride[0];
 118   rptr = ret->base_addr;
 119   sptr = array->base_addr;
 120   hptr = h->base_addr;
 121
 122   while (rptr)
 123     {
 124       /* Do the shift for this dimension.  */
 125       sh = *hptr;
 126       /* Normal case should be -len < sh < len; try to
 127          avoid the expensive remainder operation if possible.  */
 128       if (sh < 0)
 129         sh += len;
 130       if (unlikely(sh >= len || sh < 0))
 131         {
 132           sh = sh % len;
 133           if (sh < 0)
 134             sh += len;
 135         }
 136       src = &sptr[sh * soffset];
 137       dest = rptr;
 138       if (soffset == 1 && roffset == 1)
 139         {
 140           size_t len1 = sh * sizeof (GFC_REAL_4);
 141           size_t len2 = (len - sh) * sizeof (GFC_REAL_4);
 142           memcpy (rptr, sptr + sh, len2);
 143           memcpy (rptr + (len - sh), sptr, len1);
 144         }
 145       else
 146         {
 147           for (n = 0; n < len - sh; n++)
 148             {
 149               *dest = *src;
 150               dest += roffset;
 151               src += soffset;
 152             }
 153           for (src = sptr, n = 0; n < sh; n++)
 154             {
 155               *dest = *src;
 156               dest += roffset;
 157               src += soffset;
 158             }
 159         }
 160
 161       /* Advance to the next section.  */
 162       rptr += rstride0;
 163       sptr += sstride0;
 164       hptr += hstride0;
 165       count[0]++;
 166       n = 0;
 167       while (count[n] == extent[n])
 168         {
 169           /* When we get to the end of a dimension, reset it and increment
 170              the next dimension.  */
 171           count[n] = 0;
 172           rptr -= rs_ex[n];
 173           sptr -= ss_ex[n];
 174           hptr -= hs_ex[n];
 175           n++;
 176           if (n >= dim - 1)
 177             {
 178               /* Break out of the loop.  */
 179               rptr = NULL;
 180               break;
 181             }
 182           else
 183             {
 184               count[n]++;
 185               rptr += rstride[n];
 186               sptr += sstride[n];
 187               hptr += hstride[n];
 188             }
 189         }
 190     }
 191 }
 192
 193 #endif