freebsd-dev/contrib/libgmp/mpf/mul.c
markm 6ec01646dc Clean import of libgmp 2.0.2, with only the non-x86 bits removed.
BMakefiles and other bits will follow.

Requested by:	Andrey Chernov
Made world by:	Chuck Robey
1996-10-20 08:49:26 +00:00

95 lines
2.2 KiB
C

/* mpf_mul -- Multiply two floats.
Copyright (C) 1993, 1994, 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__
mpf_mul (mpf_ptr r, mpf_srcptr u, mpf_srcptr v)
#else
mpf_mul (r, u, v)
mpf_ptr r;
mpf_srcptr u;
mpf_srcptr v;
#endif
{
mp_srcptr up, vp;
mp_size_t usize, vsize;
mp_size_t sign_product;
mp_size_t prec = r->_mp_prec;
TMP_DECL (marker);
TMP_MARK (marker);
usize = u->_mp_size;
vsize = v->_mp_size;
sign_product = usize ^ vsize;
usize = ABS (usize);
vsize = ABS (vsize);
up = u->_mp_d;
vp = v->_mp_d;
if (usize > prec)
{
up += usize - prec;
usize = prec;
}
if (vsize > prec)
{
vp += vsize - prec;
vsize = prec;
}
if (usize == 0 || vsize == 0)
{
r->_mp_size = 0;
r->_mp_exp = 0; /* ??? */
}
else
{
mp_size_t rsize;
mp_limb_t cy_limb;
mp_ptr rp, tp;
mp_size_t adj;
rsize = usize + vsize;
tp = (mp_ptr) TMP_ALLOC (rsize * BYTES_PER_MP_LIMB);
cy_limb = (usize >= vsize
? mpn_mul (tp, up, usize, vp, vsize)
: mpn_mul (tp, vp, vsize, up, usize));
adj = cy_limb == 0;
rsize -= adj;
prec++;
if (rsize > prec)
{
tp += rsize - prec;
rsize = prec;
}
rp = r->_mp_d;
MPN_COPY (rp, tp, rsize);
r->_mp_exp = u->_mp_exp + v->_mp_exp - adj;
r->_mp_size = sign_product >= 0 ? rsize : -rsize;
}
TMP_FREE (marker);
}