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
|
/* Copyright (C) 1997-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef _FENV_H
# error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
#endif
/* Define bits representing the exception. We use the bit positions of
the appropriate bits in the FPSCR... */
enum
{
FE_INEXACT =
#define FE_INEXACT (1 << (31 - 6))
FE_INEXACT,
FE_DIVBYZERO =
#define FE_DIVBYZERO (1 << (31 - 5))
FE_DIVBYZERO,
FE_UNDERFLOW =
#define FE_UNDERFLOW (1 << (31 - 4))
FE_UNDERFLOW,
FE_OVERFLOW =
#define FE_OVERFLOW (1 << (31 - 3))
FE_OVERFLOW,
/* ... except for FE_INVALID, for which we use bit 31. FE_INVALID
actually corresponds to bits 7 through 12 and 21 through 23
in the FPSCR, but we can't use that because the current draft
says that it must be a power of 2. Instead we use bit 2 which
is the summary bit for all the FE_INVALID exceptions, which
kind of makes sense. */
FE_INVALID =
#define FE_INVALID (1 << (31 - 2))
FE_INVALID,
#ifdef __USE_GNU
/* Breakdown of the FE_INVALID bits. Setting FE_INVALID on an
input to a routine is equivalent to setting all of these bits;
FE_INVALID will be set on output from a routine iff one of
these bits is set. Note, though, that you can't disable or
enable these exceptions individually. */
/* Operation with SNaN. */
FE_INVALID_SNAN =
# define FE_INVALID_SNAN (1 << (31 - 7))
FE_INVALID_SNAN,
/* Inf - Inf */
FE_INVALID_ISI =
# define FE_INVALID_ISI (1 << (31 - 8))
FE_INVALID_ISI,
/* Inf / Inf */
FE_INVALID_IDI =
# define FE_INVALID_IDI (1 << (31 - 9))
FE_INVALID_IDI,
/* 0 / 0 */
FE_INVALID_ZDZ =
# define FE_INVALID_ZDZ (1 << (31 - 10))
FE_INVALID_ZDZ,
/* Inf * 0 */
FE_INVALID_IMZ =
# define FE_INVALID_IMZ (1 << (31 - 11))
FE_INVALID_IMZ,
/* Comparison with NaN or SNaN. */
FE_INVALID_COMPARE =
# define FE_INVALID_COMPARE (1 << (31 - 12))
FE_INVALID_COMPARE,
/* Invalid operation flag for software (not set by hardware). */
/* Note that some chips don't have this implemented, presumably
because no-one expected anyone to write software for them %-). */
FE_INVALID_SOFTWARE =
# define FE_INVALID_SOFTWARE (1 << (31 - 21))
FE_INVALID_SOFTWARE,
/* Square root of negative number (including -Inf). */
/* Note that some chips don't have this implemented. */
FE_INVALID_SQRT =
# define FE_INVALID_SQRT (1 << (31 - 22))
FE_INVALID_SQRT,
/* Conversion-to-integer of a NaN or a number too large or too small. */
FE_INVALID_INTEGER_CONVERSION =
# define FE_INVALID_INTEGER_CONVERSION (1 << (31 - 23))
FE_INVALID_INTEGER_CONVERSION
# define FE_ALL_INVALID \
(FE_INVALID_SNAN | FE_INVALID_ISI | FE_INVALID_IDI | FE_INVALID_ZDZ \
| FE_INVALID_IMZ | FE_INVALID_COMPARE | FE_INVALID_SOFTWARE \
| FE_INVALID_SQRT | FE_INVALID_INTEGER_CONVERSION)
#endif
};
#define FE_ALL_EXCEPT \
(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
/* PowerPC chips support all of the four defined rounding modes. We
use the bit pattern in the FPSCR as the values for the
appropriate macros. */
enum
{
FE_TONEAREST =
#define FE_TONEAREST 0
FE_TONEAREST,
FE_TOWARDZERO =
#define FE_TOWARDZERO 1
FE_TOWARDZERO,
FE_UPWARD =
#define FE_UPWARD 2
FE_UPWARD,
FE_DOWNWARD =
#define FE_DOWNWARD 3
FE_DOWNWARD
};
/* Type representing exception flags. */
typedef unsigned int fexcept_t;
/* Type representing floating-point environment. We leave it as 'double'
for efficiency reasons (rather than writing it to a 32-bit integer). */
typedef double fenv_t;
/* If the default argument is used we use this value. */
extern const fenv_t __fe_dfl_env;
#define FE_DFL_ENV (&__fe_dfl_env)
#ifdef __USE_GNU
/* Floating-point environment where all exceptions are enabled. Note that
this is not sufficient to give you SIGFPE. */
extern const fenv_t __fe_enabled_env;
# define FE_ENABLED_ENV (&__fe_enabled_env)
/* Floating-point environment with (processor-dependent) non-IEEE floating
point. */
extern const fenv_t __fe_nonieee_env;
# define FE_NONIEEE_ENV (&__fe_nonieee_env)
__BEGIN_DECLS
/* Floating-point environment with all exceptions enabled. Note that
just evaluating this value does not change the processor exception mode.
Passing this mask to fesetenv will result in a prctl syscall to change
the MSR FE0/FE1 bits to "Precise Mode". On some processors this will
result in slower floating point execution. This will last until an
fenv or exception mask is installed that disables all FP exceptions. */
extern const fenv_t *__fe_nomask_env (void);
# define FE_NOMASK_ENV FE_ENABLED_ENV
/* Floating-point environment with all exceptions disabled. Note that
just evaluating this value does not change the processor exception mode.
Passing this mask to fesetenv will result in a prctl syscall to change
the MSR FE0/FE1 bits to "Ignore Exceptions Mode". On most processors
this allows the fastest possible floating point execution.*/
extern const fenv_t *__fe_mask_env (void);
# define FE_MASK_ENV FE_DFL_ENV
__END_DECLS
#endif
|
