1/* $OpenBSD: fenv.h,v 1.3 2011/05/25 21:46:49 martynas Exp $ */
2
3/*
4 * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#ifndef _ARM_FENV_H_
20#define _ARM_FENV_H_
21
22/*
23 * Each symbol representing a floating point exception expands to an integer
24 * constant expression with values, such that bitwise-inclusive ORs of _all
25 * combinations_ of the constants result in distinct values.
26 *
27 * We use such values that allow direct bitwise operations on FPU registers.
28 */
29#define FE_INVALID 0x01
30#define FE_DIVBYZERO 0x02
31#define FE_OVERFLOW 0x04
32#define FE_UNDERFLOW 0x08
33#define FE_INEXACT 0x10
34
35/*
36 * The following symbol is simply the bitwise-inclusive OR of all floating-point
37 * exception constants defined above.
38 */
39#define FE_ALL_EXCEPT (FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | \
40 FE_UNDERFLOW | FE_INEXACT)
41
42/*
43 * Each symbol representing the rounding direction, expands to an integer
44 * constant expression whose value is distinct non-negative value.
45 *
46 * We use such values that allow direct bitwise operations on FPU registers.
47 */
48#define FE_TONEAREST 0x0
49#define FE_UPWARD 0x1
50#define FE_DOWNWARD 0x2
51#define FE_TOWARDZERO 0x3
52
53/*
54 * The following symbol is simply the bitwise-inclusive OR of all floating-point
55 * rounding direction constants defined above.
56 */
57#define _ROUND_MASK (FE_TONEAREST | FE_UPWARD | FE_DOWNWARD | \
58 FE_TOWARDZERO)
59
60/*
61 * fenv_t represents the entire floating-point environment.
62 */
63typedef struct {
64 unsigned int __sticky;
65 unsigned int __mask;
66 unsigned int __round;
67} fenv_t;
68
69/*
70 * The following constant represents the default floating-point environment
71 * (that is, the one installed at program startup) and has type pointer to
72 * const-qualified fenv_t.
73 *
74 * It can be used as an argument to the functions within the <fenv.h> header
75 * that manage the floating-point environment, namely fesetenv() and
76 * feupdateenv().
77 */
78__BEGIN_DECLS
79extern fenv_t __fe_dfl_env;
80__END_DECLS
81#define FE_DFL_ENV ((const fenv_t *)&__fe_dfl_env)
82
83/*
84 * fexcept_t represents the floating-point status flags collectively, including
85 * any status the implementation associates with the flags.
86 *
87 * A floating-point status flag is a system variable whose value is set (but
88 * never cleared) when a floating-point exception is raised, which occurs as a
89 * side effect of exceptional floating-point arithmetic to provide auxiliary
90 * information.
91 *
92 * A floating-point control mode is a system variable whose value may be set by
93 * the user to affect the subsequent behavior of floating-point arithmetic.
94 */
95typedef unsigned int fexcept_t;
96
97#endif /* !_ARM_FENV_H_ */