libgfortran/generated/norm2_r8.c

   1 /* Implementation of the NORM2 intrinsic
   2    Copyright (C) 2010-2024 Free Software Foundation, Inc.
   3    Contributed by Tobias Burnus  <burnus@net-b.de>
   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
  28
  29
  30 #if defined (HAVE_GFC_REAL_8) && defined (HAVE_GFC_REAL_8) && defined (HAVE_SQRT) && defined (HAVE_FABS)
  31
  32 #define MATHFUNC(funcname) funcname
  33
  34
  35 extern void norm2_r8 (gfc_array_r8 * const restrict,
  36         gfc_array_r8 * const restrict, const index_type * const restrict);
  37 export_proto(norm2_r8);
  38
  39 void
  40 norm2_r8 (gfc_array_r8 * const restrict retarray,
  41         gfc_array_r8 * const restrict array,
  42         const index_type * const restrict pdim)
  43 {
  44   index_type count[GFC_MAX_DIMENSIONS];
  45   index_type extent[GFC_MAX_DIMENSIONS];
  46   index_type sstride[GFC_MAX_DIMENSIONS];
  47   index_type dstride[GFC_MAX_DIMENSIONS];
  48   const GFC_REAL_8 * restrict base;
  49   GFC_REAL_8 * restrict dest;
  50   index_type rank;
  51   index_type n;
  52   index_type len;
  53   index_type delta;
  54   index_type dim;
  55   int continue_loop;
  56
  57   /* Make dim zero based to avoid confusion.  */
  58   rank = GFC_DESCRIPTOR_RANK (array) - 1;
  59   dim = (*pdim) - 1;
  60
  61   if (unlikely (dim < 0 || dim > rank))
  62     {
  63       runtime_error ("Dim argument incorrect in NORM intrinsic: "
  64                      "is %ld, should be between 1 and %ld",
  65                      (long int) dim + 1, (long int) rank + 1);
  66     }
  67
  68   len = GFC_DESCRIPTOR_EXTENT(array,dim);
  69   if (len < 0)
  70     len = 0;
  71   delta = GFC_DESCRIPTOR_STRIDE(array,dim);
  72
  73   for (n = 0; n < dim; n++)
  74     {
  75       sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n);
  76       extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
  77
  78       if (extent[n] < 0)
  79         extent[n] = 0;
  80     }
  81   for (n = dim; n < rank; n++)
  82     {
  83       sstride[n] = GFC_DESCRIPTOR_STRIDE(array, n + 1);
  84       extent[n] = GFC_DESCRIPTOR_EXTENT(array, n + 1);
  85
  86       if (extent[n] < 0)
  87         extent[n] = 0;
  88     }
  89
  90   if (retarray->base_addr == NULL)
  91     {
  92       size_t alloc_size, str;
  93
  94       for (n = 0; n < rank; n++)
  95         {
  96           if (n == 0)
  97             str = 1;
  98           else
  99             str = GFC_DESCRIPTOR_STRIDE(retarray,n-1) * extent[n-1];
 100
 101           GFC_DIMENSION_SET(retarray->dim[n], 0, extent[n] - 1, str);
 102
 103         }
 104
 105       retarray->offset = 0;
 106       retarray->dtype.rank = rank;
 107
 108       alloc_size = GFC_DESCRIPTOR_STRIDE(retarray,rank-1) * extent[rank-1];
 109
 110       retarray->base_addr = xmallocarray (alloc_size, sizeof (GFC_REAL_8));
 111       if (alloc_size == 0)
 112         return;
 113     }
 114   else
 115     {
 116       if (rank != GFC_DESCRIPTOR_RANK (retarray))
 117         runtime_error ("rank of return array incorrect in"
 118                        " NORM intrinsic: is %ld, should be %ld",
 119                        (long int) (GFC_DESCRIPTOR_RANK (retarray)),
 120                        (long int) rank);
 121
 122       if (unlikely (compile_options.bounds_check))
 123         bounds_ifunction_return ((array_t *) retarray, extent,
 124                                  "return value", "NORM");
 125     }
 126
 127   for (n = 0; n < rank; n++)
 128     {
 129       count[n] = 0;
 130       dstride[n] = GFC_DESCRIPTOR_STRIDE(retarray,n);
 131       if (extent[n] <= 0)
 132         return;
 133     }
 134
 135   base = array->base_addr;
 136   dest = retarray->base_addr;
 137
 138   continue_loop = 1;
 139   while (continue_loop)
 140     {
 141       const GFC_REAL_8 * restrict src;
 142       GFC_REAL_8 result;
 143       src = base;
 144       {
 145
 146         GFC_REAL_8 scale;
 147         result = 0;
 148         scale = 1;
 149         if (len <= 0)
 150           *dest = 0;
 151         else
 152           {
 153 #if ! defined HAVE_BACK_ARG
 154             for (n = 0; n < len; n++, src += delta)
 155               {
 156 #endif
 157
 158           if (*src != 0)
 159             {
 160               GFC_REAL_8 absX, val;
 161               absX = MATHFUNC(fabs) (*src);
 162               if (scale < absX)
 163                 {
 164                   val = scale / absX;
 165                   result = 1 + result * val * val;
 166                   scale = absX;
 167                 }
 168               else
 169                 {
 170                   val = absX / scale;
 171                   result += val * val;
 172                 }
 173             }
 174               }
 175             result = scale * MATHFUNC(sqrt) (result);
 176             *dest = result;
 177           }
 178       }
 179       /* Advance to the next element.  */
 180       count[0]++;
 181       base += sstride[0];
 182       dest += dstride[0];
 183       n = 0;
 184       while (count[n] == extent[n])
 185         {
 186           /* When we get to the end of a dimension, reset it and increment
 187              the next dimension.  */
 188           count[n] = 0;
 189           /* We could precalculate these products, but this is a less
 190              frequently used path so probably not worth it.  */
 191           base -= sstride[n] * extent[n];
 192           dest -= dstride[n] * extent[n];
 193           n++;
 194           if (n >= rank)
 195             {
 196               /* Break out of the loop.  */
 197               continue_loop = 0;
 198               break;
 199             }
 200           else
 201             {
 202               count[n]++;
 203               base += sstride[n];
 204               dest += dstride[n];
 205             }
 206         }
 207     }
 208 }
 209
 210 #endif