libgfortran/generated/norm2_r4.c

   1 /* Implementation of the NORM2 intrinsic
   2    Copyright (C) 2010-2017 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_4) && defined (HAVE_GFC_REAL_4) && defined (HAVE_SQRTF) && defined (HAVE_FABSF)
  31
  32 #define MATHFUNC(funcname) funcname ## f
  33
  34
  35 extern void norm2_r4 (gfc_array_r4 * const restrict,
  36         gfc_array_r4 * const restrict, const index_type * const restrict);
  37 export_proto(norm2_r4);
  38
  39 void
  40 norm2_r4 (gfc_array_r4 * const restrict retarray,
  41         gfc_array_r4 * 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_4 * restrict base;
  49   GFC_REAL_4 * 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 = (array->dtype & ~GFC_DTYPE_RANK_MASK) | 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_4));
 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_4 * restrict src;
 147       GFC_REAL_4 result;
 148       src = base;
 149       {
 150
 151         GFC_REAL_4 scale;
 152         result = 0;
 153         scale = 1;
 154         if (len <= 0)
 155           *dest = 0;
 156         else
 157           {
 158             for (n = 0; n < len; n++, src += delta)
 159               {
 160
 161           if (*src != 0)
 162             {
 163               GFC_REAL_4 absX, val;
 164               absX = MATHFUNC(fabs) (*src);
 165               if (scale < absX)
 166                 {
 167                   val = scale / absX;
 168                   result = 1 + result * val * val;
 169                   scale = absX;
 170                 }
 171               else
 172                 {
 173                   val = absX / scale;
 174                   result += val * val;
 175                 }
 176             }
 177               }
 178             result = scale * MATHFUNC(sqrt) (result);
 179             *dest = result;
 180           }
 181       }
 182       /* Advance to the next element.  */
 183       count[0]++;
 184       base += sstride[0];
 185       dest += dstride[0];
 186       n = 0;
 187       while (count[n] == extent[n])
 188         {
 189           /* When we get to the end of a dimension, reset it and increment
 190              the next dimension.  */
 191           count[n] = 0;
 192           /* We could precalculate these products, but this is a less
 193              frequently used path so probably not worth it.  */
 194           base -= sstride[n] * extent[n];
 195           dest -= dstride[n] * extent[n];
 196           n++;
 197           if (n >= rank)
 198             {
 199               /* Break out of the loop.  */
 200               continue_loop = 0;
 201               break;
 202             }
 203           else
 204             {
 205               count[n]++;
 206               base += sstride[n];
 207               dest += dstride[n];
 208             }
 209         }
 210     }
 211 }
 212
 213 #endif