freebsd-dev/contrib/libgmp/mpz/set_f.c

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/* mpz_set_f (dest_integer, src_float) -- Assign DEST_INTEGER from SRC_FLOAT.
Copyright (C) 1996 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 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 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 Library General Public
License for more details.
You should have received a copy of the GNU Library General Public License
along with the GNU MP 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 "gmp-impl.h"
void
#if __STDC__
mpz_set_f (mpz_ptr w, mpf_srcptr u)
#else
mpz_set_f (w, u)
mpz_ptr w;
mpf_srcptr u;
#endif
{
mp_ptr wp, up;
mp_size_t usize, size;
mp_exp_t exp;
usize = SIZ (u);
size = ABS (usize);
exp = EXP (u);
if (w->_mp_alloc < exp)
_mpz_realloc (w, exp);
wp = w->_mp_d;
up = u->_mp_d;
if (exp <= 0)
{
SIZ (w) = 0;
return;
}
if (exp < size)
{
MPN_COPY (wp, up + size - exp, exp);
}
else
{
MPN_ZERO (wp, exp - size);
MPN_COPY (wp + exp - size, up, size);
}
w->_mp_size = usize >= 0 ? exp : -exp;
}