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/* mpfr_integer_p -- test if a mpfr variable is integer.
Copyright 2001-2004, 2006-2020 Free Software Foundation, Inc.
Contributed by the AriC and Caramba projects, INRIA.
This file is part of the GNU MPFR Library.
The GNU MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at your
option) any later version.
The GNU MPFR Library 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 Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
#include "mpfr-impl.h"
int
mpfr_integer_p (mpfr_srcptr x)
{
mpfr_exp_t expo;
mpfr_prec_t prec;
mp_size_t xn;
mp_limb_t *xp;
if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(x)))
return (MPFR_IS_ZERO(x));
expo = MPFR_GET_EXP (x);
if (expo <= 0)
return 0;
prec = MPFR_PREC(x);
if ((mpfr_uexp_t) expo >= (mpfr_uexp_t) prec)
return 1;
/* 0 < expo < prec */
xn = (mp_size_t) ((prec - 1) / GMP_NUMB_BITS); /* index of last limb */
xn -= (mp_size_t) (expo / GMP_NUMB_BITS);
/* now the index of the last limb containing bits of the fractional part */
xp = MPFR_MANT(x);
MPFR_ASSERTN(xn >= 0);
if (MPFR_LIMB_LSHIFT(xp[xn], expo % GMP_NUMB_BITS) != 0)
return 0;
while (--xn >= 0)
if (xp[xn] != 0)
return 0;
return 1;
}
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