xref: /openbsd/sys/arch/powerpc64/include/fenv.h (revision 73471bf0)
1 /*	$OpenBSD: fenv.h,v 1.1 2020/06/28 08:19:34 kettenis 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	_MACHINE_FENV_H_
20 #define	_MACHINE_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_INEXACT		0x02000000
30 #define	FE_DIVBYZERO		0x04000000
31 #define	FE_UNDERFLOW		0x08000000
32 #define	FE_OVERFLOW		0x10000000
33 #define	FE_INVALID		0x20000000
34 #define	_FE_INVALID_SOFT	0x00000400
35 #define	_FE_INVALID_ALL		0x01f80700
36 
37 /*
38  * The following symbol is simply the bitwise-inclusive OR of all floating-point
39  * exception constants defined above.
40  */
41 #define	FE_ALL_EXCEPT		(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | \
42 				 FE_OVERFLOW | FE_INVALID)
43 #define	_MASK_SHIFT		22
44 
45 /*
46  * Each symbol representing the rounding direction, expands to an integer
47  * constant expression whose value is distinct non-negative value.
48  *
49  * We use such values that allow direct bitwise operations on FPU registers.
50  */
51 #define	FE_TONEAREST		0x0
52 #define	FE_TOWARDZERO		0x1
53 #define	FE_UPWARD		0x2
54 #define	FE_DOWNWARD		0x3
55 
56 /*
57  * The following symbol is simply the bitwise-inclusive OR of all floating-point
58  * rounding direction constants defined above.
59  */
60 #define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_UPWARD | \
61 				 FE_DOWNWARD)
62 
63 /*
64  * fenv_t represents the entire floating-point environment.
65  */
66 typedef	unsigned int		fenv_t;
67 
68 /*
69  * The following constant represents the default floating-point environment
70  * (that is, the one installed at program startup) and has type pointer to
71  * const-qualified fenv_t.
72  *
73  * It can be used as an argument to the functions within the <fenv.h> header
74  * that manage the floating-point environment, namely fesetenv() and
75  * feupdateenv().
76  */
77 __BEGIN_DECLS
78 extern	fenv_t			__fe_dfl_env;
79 __END_DECLS
80 #define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
81 
82 /*
83  * fexcept_t represents the floating-point status flags collectively, including
84  * any status the implementation associates with the flags.
85  *
86  * A floating-point status flag is a system variable whose value is set (but
87  * never cleared) when a floating-point exception is raised, which occurs as a
88  * side effect of exceptional floating-point arithmetic to provide auxiliary
89  * information.
90  *
91  * A floating-point control mode is a system variable whose value may be set by
92  * the user to affect the subsequent behavior of floating-point arithmetic.
93  */
94 typedef	unsigned int		fexcept_t;
95 
96 #endif	/* !_MACHINE_FENV_H_ */
97