xref: /dragonfly/contrib/mpc/src/mul_fr.c (revision a4da4a90)
1 /* mpc_mul_fr -- Multiply a complex number by a floating-point number.
2 
3 Copyright (C) 2002, 2008, 2009, 2010, 2011 INRIA
4 
5 This file is part of GNU MPC.
6 
7 GNU MPC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU Lesser General Public License as published by the
9 Free Software Foundation; either version 3 of the License, or (at your
10 option) any later version.
11 
12 GNU MPC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
15 more details.
16 
17 You should have received a copy of the GNU Lesser General Public License
18 along with this program. If not, see http://www.gnu.org/licenses/ .
19 */
20 
21 #include "mpc-impl.h"
22 
23 int
24 mpc_mul_fr (mpc_ptr a, mpc_srcptr b, mpfr_srcptr c, mpc_rnd_t rnd)
25 {
26   int inex_re, inex_im;
27   mpfr_t real;
28 
29   if (c == mpc_realref (a))
30     /* We have to use a temporary variable. */
31     mpfr_init2 (real, MPC_PREC_RE (a));
32   else
33     real [0] = mpc_realref (a) [0];
34 
35   inex_re = mpfr_mul (real, mpc_realref(b), c, MPC_RND_RE(rnd));
36   inex_im = mpfr_mul (mpc_imagref(a), mpc_imagref(b), c, MPC_RND_IM(rnd));
37   mpfr_set (mpc_realref (a), real, GMP_RNDN); /* exact */
38 
39   if (c == mpc_realref (a))
40     mpfr_clear (real);
41 
42   return MPC_INEX(inex_re, inex_im);
43 }
44