| /* mpfr_integer_p -- test if a mpfr variable is integer. |
| |
| Copyright 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. |
| Contributed by the Arenaire and Cacao 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 2.1 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.LIB. If not, 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) |
| { |
| mp_exp_t expo; |
| mp_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) / BITS_PER_MP_LIMB); /* index of last limb */ |
| xn -= (mp_size_t) (expo / BITS_PER_MP_LIMB); |
| /* now the index of the last limb containing bits of the fractional part */ |
| |
| xp = MPFR_MANT(x); |
| MPFR_ASSERTN(xn >= 0); |
| if (xp[xn] << (expo % BITS_PER_MP_LIMB) != 0) |
| return 0; |
| while (--xn >= 0) |
| if (xp[xn] != 0) |
| return 0; |
| return 1; |
| } |