1/* Copyright (C) 1997-2014 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 <http://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#include <features.h>
26
27/* Get the architecture dependend definitions. The following definitions
28 are expected to be done:
29
30 fenv_t type for object representing an entire floating-point
31 environment
32
33 FE_DFL_ENV macro of type pointer to fenv_t to be used as the argument
34 to functions taking an argument of type fenv_t; in this
35 case the default environment will be used
36
37 fexcept_t type for object representing the floating-point exception
38 flags including status associated with the flags
39
40 The following macros are defined iff the implementation supports this
41 kind of exception.
42 FE_INEXACT inexact result
43 FE_DIVBYZERO division by zero
44 FE_UNDERFLOW result not representable due to underflow
45 FE_OVERFLOW result not representable due to overflow
46 FE_INVALID invalid operation
47
48 FE_ALL_EXCEPT bitwise OR of all supported exceptions
49
50 The next macros are defined iff the appropriate rounding mode is
51 supported by the implementation.
52 FE_TONEAREST round to nearest
53 FE_UPWARD round toward +Inf
54 FE_DOWNWARD round toward -Inf
55 FE_TOWARDZERO round toward 0
56*/
57#include <bits/fenv.h>
58
59__BEGIN_DECLS
60
61/* Floating-point exception handling. */
62
63/* Clear the supported exceptions represented by EXCEPTS. */
64extern int feclearexcept (int __excepts) __THROW;
65
66/* Store implementation-defined representation of the exception flags
67 indicated by EXCEPTS in the object pointed to by FLAGP. */
68extern int fegetexceptflag (fexcept_t *__flagp, int __excepts) __THROW;
69
70/* Raise the supported exceptions represented by EXCEPTS. */
71extern int feraiseexcept (int __excepts) __THROW;
72
73/* Set complete status for exceptions indicated by EXCEPTS according to
74 the representation in the object pointed to by FLAGP. */
75extern int fesetexceptflag (const fexcept_t *__flagp, int __excepts) __THROW;
76
77/* Determine which of subset of the exceptions specified by EXCEPTS are
78 currently set. */
79extern int fetestexcept (int __excepts) __THROW;
80
81
82/* Rounding control. */
83
84/* Get current rounding direction. */
85extern int fegetround (void) __THROW;
86
87/* Establish the rounding direction represented by ROUND. */
88extern int fesetround (int __rounding_direction) __THROW;
89
90
91/* Floating-point environment. */
92
93/* Store the current floating-point environment in the object pointed
94 to by ENVP. */
95extern int fegetenv (fenv_t *__envp) __THROW;
96
97/* Save the current environment in the object pointed to by ENVP, clear
98 exception flags and install a non-stop mode (if available) for all
99 exceptions. */
100extern int feholdexcept (fenv_t *__envp) __THROW;
101
102/* Establish the floating-point environment represented by the object
103 pointed to by ENVP. */
104extern int fesetenv (const fenv_t *__envp) __THROW;
105
106/* Save current exceptions in temporary storage, install environment
107 represented by object pointed to by ENVP and raise exceptions
108 according to saved exceptions. */
109extern int feupdateenv (const fenv_t *__envp) __THROW;
110
111
112/* Include optimization. */
113#ifdef __OPTIMIZE__
114# include <bits/fenvinline.h>
115#endif
116
117#ifdef __USE_GNU
118
119/* Enable individual exceptions. Will not enable more exceptions than
120 EXCEPTS specifies. Returns the previous enabled exceptions if all
121 exceptions are successfully set, otherwise returns -1. */
122extern int feenableexcept (int __excepts) __THROW;
123
124/* Disable individual exceptions. Will not disable more exceptions than
125 EXCEPTS specifies. Returns the previous enabled exceptions if all
126 exceptions are successfully disabled, otherwise returns -1. */
127extern int fedisableexcept (int __excepts) __THROW;
128
129/* Return enabled exceptions. */
130extern int fegetexcept (void) __THROW;
131#endif
132
133__END_DECLS
134
135#endif /* fenv.h */
136