1/* Copyright (C) 1997, 1999, 2000 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, write to the Free
16   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17   02111-1307 USA.  */
18
19/*
20 * ISO C99 7.6: Floating-point environment	<fenv.h>
21 */
22
23#ifndef _FENV_H
24#define _FENV_H	1
25
26#include <features.h>
27
28/* Get the architecture dependend 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   The following macros are defined iff the implementation supports this
42   kind of exception.
43   FE_INEXACT		inexact result
44   FE_DIVBYZERO		division by zero
45   FE_UNDERFLOW		result not representable due to underflow
46   FE_OVERFLOW		result not representable due to overflow
47   FE_INVALID		invalid operation
48
49   FE_ALL_EXCEPT	bitwise OR of all supported exceptions
50
51   The next macros are defined iff the appropriate rounding mode is
52   supported by the implementation.
53   FE_TONEAREST		round to nearest
54   FE_UPWARD		round toward +Inf
55   FE_DOWNWARD		round toward -Inf
56   FE_TOWARDZERO	round toward 0
57*/
58#include <bits/fenv.h>
59
60__BEGIN_DECLS
61
62/* Floating-point exception handling.  */
63
64/* Clear the supported exceptions represented by EXCEPTS.  */
65extern int feclearexcept (int __excepts) __THROW;
66
67/* Store implementation-defined representation of the exception flags
68   indicated by EXCEPTS in the object pointed to by FLAGP.  */
69extern int fegetexceptflag (fexcept_t *__flagp, int __excepts) __THROW;
70
71/* Raise the supported exceptions represented by EXCEPTS.  */
72extern int feraiseexcept (int __excepts) __THROW;
73
74/* Set complete status for exceptions indicated by EXCEPTS according to
75   the representation in the object pointed to by FLAGP.  */
76extern int fesetexceptflag (__const fexcept_t *__flagp, int __excepts) __THROW;
77
78/* Determine which of subset of the exceptions specified by EXCEPTS are
79   currently set.  */
80extern int fetestexcept (int __excepts) __THROW;
81
82
83/* Rounding control.  */
84
85/* Get current rounding direction.  */
86extern int fegetround (void) __THROW;
87
88/* Establish the rounding direction represented by ROUND.  */
89extern int fesetround (int __rounding_direction) __THROW;
90
91
92/* Floating-point environment.  */
93
94/* Store the current floating-point environment in the object pointed
95   to by ENVP.  */
96extern int fegetenv (fenv_t *__envp) __THROW;
97
98/* Save the current environment in the object pointed to by ENVP, clear
99   exception flags and install a non-stop mode (if available) for all
100   exceptions.  */
101extern int feholdexcept (fenv_t *__envp) __THROW;
102
103/* Establish the floating-point environment represented by the object
104   pointed to by ENVP.  */
105extern int fesetenv (__const fenv_t *__envp) __THROW;
106
107/* Save current exceptions in temporary storage, install environment
108   represented by object pointed to by ENVP and raise exceptions
109   according to saved exceptions.  */
110extern int feupdateenv (__const fenv_t *__envp) __THROW;
111
112
113/* Include optimization.  */
114#ifdef __OPTIMIZE__
115# include <bits/fenvinline.h>
116#endif
117
118#ifdef __USE_GNU
119
120/* Enable individual exceptions.  Will not enable more exceptions than
121   EXCEPTS specifies.  Returns the previous enabled exceptions if all
122   exceptions are successfully set, otherwise returns -1.  */
123extern int feenableexcept (int __excepts) __THROW;
124
125/* Disable individual exceptions.  Will not disable more exceptions than
126   EXCEPTS specifies.  Returns the previous enabled exceptions if all
127   exceptions are successfully disabled, otherwise returns -1.  */
128extern int fedisableexcept (int __excepts) __THROW;
129
130/* Return enabled exceptions.  */
131extern int fegetexcept (void) __THROW;
132#endif
133
134__END_DECLS
135
136#endif /* fenv.h */
137