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
|
/* Copyright (C) 1997, 1998, 1999, 2000, 2011 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#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 FPU control word. */
enum
{
FE_INVALID = 0x01,
#define FE_INVALID FE_INVALID
__FE_DENORM = 0x02,
FE_DIVBYZERO = 0x04,
#define FE_DIVBYZERO FE_DIVBYZERO
FE_OVERFLOW = 0x08,
#define FE_OVERFLOW FE_OVERFLOW
FE_UNDERFLOW = 0x10,
#define FE_UNDERFLOW FE_UNDERFLOW
FE_INEXACT = 0x20
#define FE_INEXACT FE_INEXACT
};
#define FE_ALL_EXCEPT \
(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
/* The ix87 FPU supports all of the four defined rounding modes. We
use again the bit positions in the FPU control word as the values
for the appropriate macros. */
enum
{
FE_TONEAREST = 0,
#define FE_TONEAREST FE_TONEAREST
FE_DOWNWARD = 0x400,
#define FE_DOWNWARD FE_DOWNWARD
FE_UPWARD = 0x800,
#define FE_UPWARD FE_UPWARD
FE_TOWARDZERO = 0xc00
#define FE_TOWARDZERO FE_TOWARDZERO
};
/* Type representing exception flags. */
typedef unsigned short int fexcept_t;
/* Type representing floating-point environment. This function corresponds
to the layout of the block written by the `fstenv'. */
typedef struct
{
unsigned short int __control_word;
unsigned short int __unused1;
unsigned short int __status_word;
unsigned short int __unused2;
unsigned short int __tags;
unsigned short int __unused3;
unsigned int __eip;
unsigned short int __cs_selector;
unsigned int __opcode:11;
unsigned int __unused4:5;
unsigned int __data_offset;
unsigned short int __data_selector;
unsigned short int __unused5;
}
fenv_t;
/* If the default argument is used we use this value. */
#define FE_DFL_ENV ((const fenv_t *) -1)
#ifdef __USE_GNU
/* Floating-point environment where none of the exception is masked. */
# define FE_NOMASK_ENV ((const fenv_t *) -2)
#endif
#ifdef __USE_EXTERN_INLINES
__BEGIN_DECLS
/* Optimized versions. */
extern int __REDIRECT_NTH (__feraiseexcept_renamed, (int), feraiseexcept);
__extern_inline int
__NTH (feraiseexcept (int __excepts))
{
if (__builtin_constant_p (__excepts)
&& (__excepts & ~(FE_INVALID | FE_DIVBYZERO)) == 0)
{
if ((FE_INVALID & __excepts) != 0)
{
/* One example of a invalid operation is 0.0 / 0.0. */
float __f = 0.0;
# ifdef __SSE_MATH__
__asm__ __volatile__ ("divss %0, %0 " : : "x" (__f));
# else
__asm__ __volatile__ ("fdiv %%st, %%st(0); fwait"
: "=t" (__f) : "0" (__f));
# endif
(void) &__f;
}
if ((FE_DIVBYZERO & __excepts) != 0)
{
float __f = 1.0;
float __g = 0.0;
# ifdef __SSE_MATH__
__asm__ __volatile__ ("divss %1, %0" : : "x" (__f), "x" (__g));
# else
__asm__ __volatile__ ("fdivp %%st(1), %%st; fwait"
: "=t" (__f) : "0" (__f), "u" (__g) : "st(1)");
# endif
(void) &__f;
}
return 0;
}
return __feraiseexcept_renamed (__excepts);
}
__END_DECLS
#endif
|
