xref: /openbsd/sys/arch/alpha/include/fenv.h (revision 3d8817e4)
1 /*	$OpenBSD: fenv.h,v 1.1 2011/04/23 22:39:14 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	_ALPHA_FENV_H_
20 #define	_ALPHA_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 #define	FE_INTOVERFLOW		0x20
35 
36 /*
37  * The following symbol is simply the bitwise-inclusive OR of all floating-point
38  * exception constants defined above.
39  */
40 #define	FE_ALL_EXCEPT		\
41 	(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW | \
42 	 FE_INTOVERFLOW)
43 
44 /*
45  * Each symbol representing the rounding direction, expands to an integer
46  * constant expression whose value is distinct non-negative value.
47  *
48  * We use such values that allow direct bitwise operations on FPU registers.
49  */
50 #define	FE_TOWARDZERO		0x0
51 #define	FE_DOWNWARD		0x1
52 #define	FE_TONEAREST		0x2
53 #define	FE_UPWARD		0x3
54 
55 /*
56  * The following symbol is simply the bitwise-inclusive OR of all floating-point
57  * rounding direction constants defined above.
58  */
59 #define	_ROUND_MASK		\
60 	(FE_TOWARDZERO | FE_DOWNWARD | FE_TONEAREST | FE_UPWARD)
61 #define	_ROUND_SHIFT		58
62 
63 /*
64  * fenv_t represents the entire floating-point environment
65  */
66 typedef struct {
67 	unsigned short __excepts;
68 	unsigned short __mask;
69 	unsigned short __round;
70 } fenv_t;
71 
72 extern fenv_t			__fe_dfl_env;
73 #define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
74 
75 /*
76  * fexcept_t represents the floating-point status flags collectively, including
77  * any status the implementation associates with the flags.
78  *
79  * A floating-point status flag is a system variable whose value is set (but
80  * never cleared) when a floating-point exception is raised, which occurs as a
81  * side effect of exceptional floating-point arithmetic to provide auxiliary
82  * information.
83  *
84  * A floating-point control mode is a system variable whose value may be set by
85  * the user to affect the subsequent behavior of floating-point arithmetic.
86  */
87 typedef unsigned short fexcept_t;
88 
89 #endif	/* ! _ALPHA_FENV_H_ */
90