1/* GCC Quad-Precision Math Library
2 Copyright (C) 2012 Free Software Foundation, Inc.
3
4This file is part of the libquadmath library.
5Libquadmath is free software; you can redistribute it and/or
6modify it under the terms of the GNU Library General Public
7License as published by the Free Software Foundation; either
8version 2 of the License, or (at your option) any later version.
9
10Libquadmath is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13Library General Public License for more details.
14
15You should have received a copy of the GNU Library General Public
16License along with libquadmath; see the file COPYING.LIB. If
17not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
18Boston, MA 02110-1301, USA. */
19
20
21#ifndef QUADMATH_ROUNDING_MODE_H
22#define QUADMATH_ROUNDING_MODE_H
23
24#include <stdbool.h>
25
26
27#if defined(HAVE_FENV_H)
28# include <fenv.h>
29#endif /* HAVE_FENV_H */
30
31static inline int
32get_rounding_mode (void)
33{
34#if defined(HAVE_FENV_H) && (defined(FE_DOWNWARD) || defined(FE_TONEAREST) \
35 || defined(FE_TOWARDZERO) || defined(FE_UPWARD))
36 return fegetround ();
37#else
38 return 0;
39#endif
40}
41
42static inline bool
43round_away (bool negative, bool last_digit_odd, bool half_bit, bool more_bits,
44 int mode)
45{
46 switch (mode)
47 {
48#ifdef FE_DOWNWARD
49 case FE_DOWNWARD:
50 return negative && (half_bit || more_bits);
51#endif
52
53#ifdef FE_DOWNWARD
54 case FE_TONEAREST:
55 return half_bit && (last_digit_odd || more_bits);
56#endif
57
58#ifdef FE_TOWARDZERO
59 case FE_TOWARDZERO:
60 return false;
61#endif
62
63
64#ifdef FE_UPWARD
65 case FE_UPWARD:
66 return !negative && (half_bit || more_bits);
67#endif
68
69 default:
70 return false;
71 }
72}
73
74#endif /* QUADMATH_ROUNDING_MODE_H */
75