1 /* mpfr_sub_d -- subtract a machine double precision float from
2 a multiple precision floating-point number
4 Copyright 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
5 Contributed by the AriC and Caramel projects, INRIA.
7 This file is part of the GNU MPFR Library.
9 The GNU MPFR Library is free software; you can redistribute it and/or modify
10 it under the terms of the GNU Lesser General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or (at your
12 option) any later version.
14 The GNU MPFR Library is distributed in the hope that it will be useful, but
15 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17 License for more details.
19 You should have received a copy of the GNU Lesser General Public License
20 along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
21 http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
22 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
24 #include "mpfr-impl.h"
27 mpfr_sub_d (mpfr_ptr a
, mpfr_srcptr b
, double c
, mpfr_rnd_t rnd_mode
)
31 MPFR_SAVE_EXPO_DECL (expo
);
34 (("b[%Pu]=%.*Rg c=%.20g rnd=%d",
35 mpfr_get_prec (b
), mpfr_log_prec
, b
, c
, rnd_mode
),
36 ("a[%Pu]=%.*Rg", mpfr_get_prec (a
), mpfr_log_prec
, a
));
38 MPFR_SAVE_EXPO_MARK (expo
);
40 mpfr_init2 (d
, IEEE_DBL_MANT_DIG
);
41 inexact
= mpfr_set_d (d
, c
, rnd_mode
);
42 MPFR_ASSERTN (inexact
== 0);
45 inexact
= mpfr_sub (a
, b
, d
, rnd_mode
);
46 MPFR_SAVE_EXPO_UPDATE_FLAGS (expo
, __gmpfr_flags
);
49 MPFR_SAVE_EXPO_FREE (expo
);
50 return mpfr_check_range (a
, inexact
, rnd_mode
);