glibc (2.38)
1 /* Copyright (C) 1997-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 /*
19 * ISO C99 7.6: Floating-point environment <fenv.h>
20 */
21
22 #ifndef _FENV_H
23 #define _FENV_H 1
24
25 #define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION
26 #include <bits/libc-header-start.h>
27
28 /* Get the architecture dependent definitions. The following definitions
29 are expected to be done:
30
31 fenv_t type for object representing an entire floating-point
32 environment
33
34 FE_DFL_ENV macro of type pointer to fenv_t to be used as the argument
35 to functions taking an argument of type fenv_t; in this
36 case the default environment will be used
37
38 fexcept_t type for object representing the floating-point exception
39 flags including status associated with the flags
40
41 femode_t type for object representing floating-point control modes
42
43 FE_DFL_MODE macro of type pointer to const femode_t to be used as the
44 argument to fesetmode; in this case the default control
45 modes will be used
46
47 The following macros are defined iff the implementation supports this
48 kind of exception.
49 FE_INEXACT inexact result
50 FE_DIVBYZERO division by zero
51 FE_UNDERFLOW result not representable due to underflow
52 FE_OVERFLOW result not representable due to overflow
53 FE_INVALID invalid operation
54
55 FE_ALL_EXCEPT bitwise OR of all supported exceptions
56
57 The next macros are defined iff the appropriate rounding mode is
58 supported by the implementation.
59 FE_TONEAREST round to nearest
60 FE_UPWARD round toward +Inf
61 FE_DOWNWARD round toward -Inf
62 FE_TOWARDZERO round toward 0
63 */
64 #include <bits/fenv.h>
65
66 __BEGIN_DECLS
67
68 /* Floating-point exception handling. */
69
70 /* Clear the supported exceptions represented by EXCEPTS. */
71 extern int feclearexcept (int __excepts) __THROW;
72
73 /* Store implementation-defined representation of the exception flags
74 indicated by EXCEPTS in the object pointed to by FLAGP. */
75 extern int fegetexceptflag (fexcept_t *__flagp, int __excepts) __THROW;
76
77 /* Raise the supported exceptions represented by EXCEPTS. */
78 extern int feraiseexcept (int __excepts) __THROW;
79
80 #if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
81 /* Set the supported exception flags represented by EXCEPTS, without
82 causing enabled traps to be taken. */
83 extern int fesetexcept (int __excepts) __THROW;
84 #endif
85
86 /* Set complete status for exceptions indicated by EXCEPTS according to
87 the representation in the object pointed to by FLAGP. */
88 extern int fesetexceptflag (const fexcept_t *__flagp, int __excepts) __THROW;
89
90 /* Determine which of subset of the exceptions specified by EXCEPTS are
91 currently set. */
92 extern int fetestexcept (int __excepts) __THROW;
93
94 #if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
95 /* Determine which of subset of the exceptions specified by EXCEPTS
96 are set in *FLAGP. */
97 extern int fetestexceptflag (const fexcept_t *__flagp, int __excepts) __THROW;
98 #endif
99
100
101 /* Rounding control. */
102
103 /* Get current rounding direction. */
104 extern int fegetround (void) __THROW __attribute_pure__;
105
106 /* Establish the rounding direction represented by ROUND. */
107 extern int fesetround (int __rounding_direction) __THROW;
108
109
110 /* Floating-point environment. */
111
112 /* Store the current floating-point environment in the object pointed
113 to by ENVP. */
114 extern int fegetenv (fenv_t *__envp) __THROW;
115
116 /* Save the current environment in the object pointed to by ENVP, clear
117 exception flags and install a non-stop mode (if available) for all
118 exceptions. */
119 extern int feholdexcept (fenv_t *__envp) __THROW;
120
121 /* Establish the floating-point environment represented by the object
122 pointed to by ENVP. */
123 extern int fesetenv (const fenv_t *__envp) __THROW;
124
125 /* Save current exceptions in temporary storage, install environment
126 represented by object pointed to by ENVP and raise exceptions
127 according to saved exceptions. */
128 extern int feupdateenv (const fenv_t *__envp) __THROW;
129
130
131 /* Control modes. */
132
133 #if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
134 /* Store the current floating-point control modes in the object
135 pointed to by MODEP. */
136 extern int fegetmode (femode_t *__modep) __THROW;
137
138 /* Establish the floating-point control modes represented by the
139 object pointed to by MODEP. */
140 extern int fesetmode (const femode_t *__modep) __THROW;
141 #endif
142
143
144 /* NaN support. */
145
146 #if (__GLIBC_USE (IEC_60559_BFP_EXT_C2X) \
147 && defined FE_INVALID \
148 && defined __SUPPORT_SNAN__)
149 # define FE_SNANS_ALWAYS_SIGNAL 1
150 #endif
151
152 #ifdef __USE_GNU
153
154 /* Enable individual exceptions. Will not enable more exceptions than
155 EXCEPTS specifies. Returns the previous enabled exceptions if all
156 exceptions are successfully set, otherwise returns -1. */
157 extern int feenableexcept (int __excepts) __THROW;
158
159 /* Disable individual exceptions. Will not disable more exceptions than
160 EXCEPTS specifies. Returns the previous enabled exceptions if all
161 exceptions are successfully disabled, otherwise returns -1. */
162 extern int fedisableexcept (int __excepts) __THROW;
163
164 /* Return enabled exceptions. */
165 extern int fegetexcept (void) __THROW;
166 #endif
167
168 __END_DECLS
169
170 #endif /* fenv.h */
Browse
Usage
Versions