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/* mpfr_set -- copy of a floating-point number
Copyright (C) 1999 PolKA project, Inria Lorraine and Loria
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 <stdio.h>
#include "gmp.h"
#include "gmp-impl.h"
#include "mpfr.h"
void
#if __STDC__
mpfr_set4(mpfr_ptr a, mpfr_srcptr b, mp_rnd_t rnd_mode, int signb)
#else
mpfr_set4(a, b, rnd_mode, signb)
mpfr_ptr a;
mpfr_srcptr b;
mp_rnd_t rnd_mode;
int signb;
#endif
{
int carry, an, preca = MPFR_PREC(a), sh; mp_limb_t *ap = MPFR_MANT(a);
if (MPFR_IS_NAN(b)) { MPFR_SET_NAN(a); return; }
if (MPFR_IS_INF(b))
{
MPFR_SET_INF(a);
if (MPFR_SIGN(a) * signb < 0) MPFR_CHANGE_SIGN(a);
return;
}
carry = mpfr_round_raw(ap, MPFR_MANT(b), MPFR_PREC(b), (signb<0), preca, rnd_mode);
MPFR_EXP(a) = MPFR_EXP(b);
if (carry) {
an = (preca-1)/BITS_PER_MP_LIMB + 1;
sh = an * BITS_PER_MP_LIMB - preca;
if ((*ap >> sh) & 1) {
fprintf(stderr, "unable to round in mpfr_set\n"); exit(1);
}
mpn_rshift(ap, ap, an, 1);
ap[an-1] |= (mp_limb_t) 1 << (BITS_PER_MP_LIMB-1);
MPFR_EXP(a)++;
}
if (MPFR_SIGN(a) * signb < 0) MPFR_CHANGE_SIGN(a);
}
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