1/* mpfr_integer_p -- test if a mpfr variable is integer. 2 3Copyright 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. 4Contributed by the Arenaire and Cacao projects, INRIA. 5 6This file is part of the GNU MPFR Library. 7 8The GNU MPFR Library is free software; you can redistribute it and/or modify 9it under the terms of the GNU Lesser General Public License as published by 10the Free Software Foundation; either version 3 of the License, or (at your 11option) any later version. 12 13The GNU MPFR Library is distributed in the hope that it will be useful, but 14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 15or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 16License for more details. 17 18You should have received a copy of the GNU Lesser General Public License 19along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see 20http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., 2151 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ 22 23 24#include "mpfr-impl.h" 25 26int 27mpfr_integer_p (mpfr_srcptr x) 28{ 29 mpfr_exp_t expo; 30 mpfr_prec_t prec; 31 mp_size_t xn; 32 mp_limb_t *xp; 33 34 if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(x))) 35 return (MPFR_IS_ZERO(x)); 36 37 expo = MPFR_GET_EXP (x); 38 if (expo <= 0) 39 return 0; 40 41 prec = MPFR_PREC(x); 42 if ((mpfr_uexp_t) expo >= (mpfr_uexp_t) prec) 43 return 1; 44 45 /* 0 < expo < prec */ 46 47 xn = (mp_size_t) ((prec - 1) / GMP_NUMB_BITS); /* index of last limb */ 48 xn -= (mp_size_t) (expo / GMP_NUMB_BITS); 49 /* now the index of the last limb containing bits of the fractional part */ 50 51 xp = MPFR_MANT(x); 52 MPFR_ASSERTN(xn >= 0); 53 if (xp[xn] << (expo % GMP_NUMB_BITS) != 0) 54 return 0; 55 while (--xn >= 0) 56 if (xp[xn] != 0) 57 return 0; 58 return 1; 59} 60