libgfortran/generated/norm2_r8.c

   1 /* Implementation of the NORM2 intrinsic
   2    Copyright (C) 2010-2018 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         {
 113           /* Make sure we have a zero-sized array.  */
 114           GFC_DIMENSION_SET(retarray->dim[0], 0, -1, 1);
 115           return;
 116
 117         }
 118     }
 119   else
 120     {
 121       if (rank != GFC_DESCRIPTOR_RANK (retarray))
 122         runtime_error ("rank of return array incorrect in"
 123                        " NORM intrinsic: is %ld, should be %ld",
 124                        (long int) (GFC_DESCRIPTOR_RANK (retarray)),
 125                        (long int) rank);
 126
 127       if (unlikely (compile_options.bounds_check))
 128         bounds_ifunction_return ((array_t *) retarray, extent,
 129                                  "return value", "NORM");
 130     }
 131
 132   for (n = 0; n < rank; n++)
 133     {
 134       count[n] = 0;
 135       dstride[n] = GFC_DESCRIPTOR_STRIDE(retarray,n);
 136       if (extent[n] <= 0)
 137         return;
 138     }
 139
 140   base = array->base_addr;
 141   dest = retarray->base_addr;
 142
 143   continue_loop = 1;
 144   while (continue_loop)
 145     {
 146       const GFC_REAL_8 * restrict src;
 147       GFC_REAL_8 result;
 148       src = base;
 149       {
 150
 151         GFC_REAL_8 scale;
 152         result = 0;
 153         scale = 1;
 154         if (len <= 0)
 155           *dest = 0;
 156         else
 157           {
 158 #if ! defined HAVE_BACK_ARG
 159             for (n = 0; n < len; n++, src += delta)
 160               {
 161 #endif
 162
 163           if (*src != 0)
 164             {
 165               GFC_REAL_8 absX, val;
 166               absX = MATHFUNC(fabs) (*src);
 167               if (scale < absX)
 168                 {
 169                   val = scale / absX;
 170                   result = 1 + result * val * val;
 171                   scale = absX;
 172                 }
 173               else
 174                 {
 175                   val = absX / scale;
 176                   result += val * val;
 177                 }
 178             }
 179               }
 180             result = scale * MATHFUNC(sqrt) (result);
 181             *dest = result;
 182           }
 183       }
 184       /* Advance to the next element.  */
 185       count[0]++;
 186       base += sstride[0];
 187       dest += dstride[0];
 188       n = 0;
 189       while (count[n] == extent[n])
 190         {
 191           /* When we get to the end of a dimension, reset it and increment
 192              the next dimension.  */
 193           count[n] = 0;
 194           /* We could precalculate these products, but this is a less
 195              frequently used path so probably not worth it.  */
 196           base -= sstride[n] * extent[n];
 197           dest -= dstride[n] * extent[n];
 198           n++;
 199           if (n >= rank)
 200             {
 201               /* Break out of the loop.  */
 202               continue_loop = 0;
 203               break;
 204             }
 205           else
 206             {
 207               count[n]++;
 208               base += sstride[n];
 209               dest += dstride[n];
 210             }
 211         }
 212     }
 213 }
 214
 215 #endif