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/* mpfr_set_q -- set a floating-point number from a multiple-precision rational
Copyright (C) 2000 Free Software Foundation.
This file is part of the MPFR Library.
The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
The 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 Library General Public
License for more details.
You should have received a copy of the GNU Library General Public License
along with the MPFR Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include "gmp.h"
#include "mpfr.h"
#include "gmp-impl.h"
#include "longlong.h"
/* set f to the rational q */
void
#if __STDC__
mpfr_set_q (mpfr_ptr f, mpq_srcptr q, mp_rnd_t rnd)
#else
mpfr_set_q (f, q, rnd)
mpfr_ptr f;
mpq_srcptr q;
mp_rnd_t rnd;
#endif
{
int sign;
mpz_srcptr num, den;
unsigned int prec;
mpfr_t n,d;
MPFR_CLEAR_FLAGS(f);
num = mpq_numref(q);
sign = mpz_cmp_ui(num, 0);
if (sign==0) {
MPFR_SET_ZERO(f);
return;
}
den = mpq_denref(q);
prec = MPFR_PREC(f);
mpfr_init2(n, mpz_sizeinbase(num, 2));
mpfr_set_z(n, num, GMP_RNDZ); /* result is exact */
mpfr_init2(d, mpz_sizeinbase(den, 2));
mpfr_set_z(d, den, GMP_RNDZ); /* result is exact */
MPFR_PREC(f) = prec;
mpfr_div(f, n, d, rnd);
mpfr_clear(n); mpfr_clear(d);
}
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