efee5258bc
The MPFR library is a C library for multiple-precision floating-point computations with exact rounding (also called correct rounding). It is based on the GMP multiple-precision library and should replace the MPF class in further releases of GMP. GCC >= 4.2 requires MPFR.
60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
/* mpfr_integer_p -- test if a mpfr variable is integer.
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Copyright 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
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Contributed by the Arenaire and Cacao projects, INRIA.
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This file is part of the GNU MPFR Library.
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The GNU MPFR Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 3 of the License, or (at your
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option) any later version.
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The GNU MPFR Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
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http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
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51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
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#include "mpfr-impl.h"
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int
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mpfr_integer_p (mpfr_srcptr x)
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{
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mpfr_exp_t expo;
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mpfr_prec_t prec;
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mp_size_t xn;
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mp_limb_t *xp;
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if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(x)))
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return (MPFR_IS_ZERO(x));
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expo = MPFR_GET_EXP (x);
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if (expo <= 0)
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return 0;
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prec = MPFR_PREC(x);
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if ((mpfr_uexp_t) expo >= (mpfr_uexp_t) prec)
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return 1;
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/* 0 < expo < prec */
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xn = (mp_size_t) ((prec - 1) / GMP_NUMB_BITS); /* index of last limb */
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xn -= (mp_size_t) (expo / GMP_NUMB_BITS);
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/* now the index of the last limb containing bits of the fractional part */
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xp = MPFR_MANT(x);
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MPFR_ASSERTN(xn >= 0);
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if (xp[xn] << (expo % GMP_NUMB_BITS) != 0)
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return 0;
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while (--xn >= 0)
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if (xp[xn] != 0)
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return 0;
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return 1;
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}
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