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/* mpf_trunc -- truncate an mpf to an integer.
Copyright 2001 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP 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 3 of the License, or (at your
option) any later version.
The GNU MP 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 MP Library. If not, see http://www.gnu.org/licenses/. */
#include "gmp.h"
#include "gmp-impl.h"
/* Notice the use of prec+1 ensures mpf_trunc is equivalent to mpf_set if u
is already an integer. */
void
mpf_trunc (mpf_ptr r, mpf_srcptr u)
{
mp_ptr rp;
mp_srcptr up;
mp_size_t size, asize, prec;
mp_exp_t exp;
exp = EXP(u);
size = SIZ(u);
if (size == 0 || exp <= 0)
{
/* u is only a fraction */
SIZ(r) = 0;
EXP(r) = 0;
return;
}
up = PTR(u);
EXP(r) = exp;
asize = ABS (size);
up += asize;
/* skip fraction part of u */
asize = MIN (asize, exp);
/* don't lose precision in the copy */
prec = PREC(r) + 1;
/* skip excess over target precision */
asize = MIN (asize, prec);
up -= asize;
rp = PTR(r);
SIZ(r) = (size >= 0 ? asize : -asize);
if (rp != up)
MPN_COPY_INCR (rp, up, asize);
}
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