pqc/external/flint-2.4.3/fmpz/clrbit.c
2014-05-24 23:16:06 +02:00

47 lines
1.4 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) 2012 Sebastian Pancratz
******************************************************************************/
#include "fmpz.h"
void fmpz_clrbit(fmpz_t f, ulong i)
{
if (!COEFF_IS_MPZ(*f))
{
if (i < FLINT_BITS - 2)
{
*f &= ~(WORD(1) << i);
}
/* i >= FLINT_BITS --> nop */
}
else
{
__mpz_struct *ptr = COEFF_TO_PTR(*f);
mpz_clrbit(ptr, i);
_fmpz_demote_val(f);
}
}