arb/arf/is_int.c
2016-04-26 17:20:05 +02:00

33 lines
766 B
C

/*
Copyright (C) 2016 Fredrik Johansson
This file is part of Arb.
Arb is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "arf.h"
int
arf_is_int(const arf_t x)
{
mp_size_t xn;
mp_srcptr xp;
slong exp, c;
exp = ARF_EXP(x);
if (ARF_IS_SPECIAL(x))
return exp == ARF_EXP_ZERO;
if (COEFF_IS_MPZ(exp))
return mpz_sgn(COEFF_TO_PTR(exp)) > 0;
ARF_GET_MPN_READONLY(xp, xn, x);
count_trailing_zeros(c, xp[0]);
return exp - xn * FLINT_BITS + c >= 0;
}