pqc/external/flint-2.4.3/long_extras/sizeinbase.c

64 lines
1.6 KiB
C

/*=============================================================================
This file is part of FLINT.
FLINT 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 of the License, or
(at your option) any later version.
FLINT 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 FLINT; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2011 Sebastian Pancratz
******************************************************************************/
#include <stdlib.h>
#include <limits.h>
#include "flint.h"
size_t z_sizeinbase(slong n, int b)
{
slong c = 0;
if (n == 0)
{
return 1;
}
if (n <= 0)
{
if (n > WORD_MIN)
{
n = -n;
}
else /* n == WORD_MIN */
{
if (n % b)
{
n = - (n + 1);
}
else
{
n = - (n / b);
c = 1;
}
}
}
for ( ; n > 0; n /= b, c++) ;
return c;
}