checksum.c

Go to the documentation of this file.

/*
 Copyright (C) 2010 X. Andrade
 Copyright (C) 2021 S. Ohlmann
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2, or (at your option)
 any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 02110-1301, USA.
 
*/
 
#include <config.h>
#include <fortran_types.h>
 
/* This function implements a very stupid checksum function. The only
   important thing is that it produces different results for arrays
   with the same numbers but in different orders. For more serious
   applications a better function must be used. */
 
void FC_FUNC_(checksum_calculate,
              CHECKSUM_CALCULATE)(const fint *algorithm, const fint8 *narray,
                                  const fint8 *array, fint8 *sum) {
  fint8 i;
  fint8 mult;
  *sum = 0;
  mult = 1;
  for (i = 0; i < *narray; i++) {
    *sum += mult * array[i];
    mult++;
  }
}