1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
/*-
* Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _FENV_H_
#define _FENV_H_
#include <sys/_types.h>
typedef __uint64_t fenv_t;
typedef __uint16_t fexcept_t;
/* Exception flags */
#define FE_INVALID 0x02
#define FE_DIVBYZERO 0x04
#define FE_OVERFLOW 0x08
#define FE_UNDERFLOW 0x10
#define FE_INEXACT 0x20
#define FE_INTOVF 0x40 /* not maskable */
#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INTOVF | \
FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
/* Rounding modes */
#define FE_TOWARDZERO 0x00
#define FE_DOWNWARD 0x01
#define FE_TONEAREST 0x02
#define FE_UPWARD 0x03
#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
FE_UPWARD | FE_TOWARDZERO)
#define _ROUND_SHIFT 58
#define _FPUSW_SHIFT 51
#define __excb() __asm __volatile("excb")
#define __mf_fpcr(__cw) __asm __volatile("mf_fpcr %0" : "=f" (*(__cw)))
#define __mt_fpcr(__cw) __asm __volatile("mt_fpcr %0" : : "f" (__cw))
union __fpcr {
double __d;
fenv_t __bits;
};
__BEGIN_DECLS
/* Default floating-point environment */
extern const fenv_t __fe_dfl_env;
#define FE_DFL_ENV (&__fe_dfl_env)
static __inline int
feclearexcept(int __excepts)
{
union __fpcr __r;
__excb();
__mf_fpcr(&__r.__d);
__r.__bits &= ~((fenv_t)__excepts << _FPUSW_SHIFT);
__mt_fpcr(__r.__d);
__excb();
return (0);
}
static __inline int
fegetexceptflag(fexcept_t *__flagp, int __excepts)
{
union __fpcr __r;
__excb();
__mf_fpcr(&__r.__d);
__excb();
*__flagp = (__r.__bits >> _FPUSW_SHIFT) & __excepts;
return (0);
}
static __inline int
fesetexceptflag(const fexcept_t *__flagp, int __excepts)
{
union __fpcr __r;
fenv_t __xflag, __xexcepts;
__xflag = (fenv_t)*__flagp << _FPUSW_SHIFT;
__xexcepts = (fenv_t)__excepts << _FPUSW_SHIFT;
__excb();
__mf_fpcr(&__r.__d);
__r.__bits &= ~__xexcepts;
__r.__bits |= __xflag & __xexcepts;
__mt_fpcr(__r.__d);
__excb();
return (0);
}
static __inline int
feraiseexcept(int __excepts)
{
/*
* XXX Generating exceptions this way does not actually invoke
* a userland trap handler when enabled, but neither do
* arithmetic operations as far as I can tell. Perhaps there
* are more bugs in the kernel trap handler.
*/
fexcept_t __ex = __excepts;
fesetexceptflag(&__ex, __excepts);
return (0);
}
static __inline int
fetestexcept(int __excepts)
{
union __fpcr __r;
__excb();
__mf_fpcr(&__r.__d);
__excb();
return ((__r.__bits >> _FPUSW_SHIFT) & __excepts);
}
static __inline int
fegetround(void)
{
union __fpcr __r;
/*
* No exception barriers should be required here if we assume
* that only fesetround() can change the rounding mode.
*/
__mf_fpcr(&__r.__d);
return ((int)(__r.__bits >> _ROUND_SHIFT) & _ROUND_MASK);
}
static __inline int
fesetround(int __round)
{
union __fpcr __r;
if (__round & ~_ROUND_MASK)
return (-1);
__excb();
__mf_fpcr(&__r.__d);
__r.__bits &= ~((fenv_t)_ROUND_MASK << _ROUND_SHIFT);
__r.__bits |= (fenv_t)__round << _ROUND_SHIFT;
__mt_fpcr(__r.__d);
__excb();
return (0);
}
int fegetenv(fenv_t *__envp);
int feholdexcept(fenv_t *__envp);
int fesetenv(const fenv_t *__envp);
int feupdateenv(const fenv_t *__envp);
#if __BSD_VISIBLE
int feenableexcept(int __mask);
int fedisableexcept(int __mask);
int fegetexcept(void);
#endif /* __BSD_VISIBLE */
__END_DECLS
#endif /* !_FENV_H_ */
|
