/* Copyright (C) 1997, 1999, 2000 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. */

/*
* ISO C99 7.6: Floating-point environment <fenv.h>
*/

#ifndef _FENV_H
#define _FENV_H 1

#include <features.h>

/* Get the architecture dependend definitions. The following definitions
are expected to be done:

fenv_t type for object representing an entire floating-point
environment

FE_DFL_ENV macro of type pointer to fenv_t to be used as the argument
to functions taking an argument of type fenv_t; in this
case the default environment will be used

fexcept_t type for object representing the floating-point exception
flags including status associated with the flags

The following macros are defined iff the implementation supports this
kind of exception.
FE_INEXACT inexact result
FE_DIVBYZERO division by zero
FE_UNDERFLOW result not representable due to underflow
FE_OVERFLOW result not representable due to overflow
FE_INVALID invalid operation

FE_ALL_EXCEPT bitwise OR of all supported exceptions

The next macros are defined iff the appropriate rounding mode is
supported by the implementation.
FE_TONEAREST round to nearest
FE_UPWARD round toward +Inf
FE_DOWNWARD round toward -Inf
FE_TOWARDZERO round toward 0
*/
#include <bits/fenv.h>

__BEGIN_DECLS

/* Floating-point exception handling. */

/* Clear the supported exceptions represented by EXCEPTS. */
extern int feclearexcept (int __excepts) __THROW;

/* Store implementation-defined representation of the exception flags
indicated by EXCEPTS in the object pointed to by FLAGP. */
extern int fegetexceptflag (fexcept_t *__flagp, int __excepts) __THROW;

/* Raise the supported exceptions represented by EXCEPTS. */
extern int feraiseexcept (int __excepts) __THROW;

/* Set complete status for exceptions indicated by EXCEPTS according to
the representation in the object pointed to by FLAGP. */
extern int fesetexceptflag (__const fexcept_t *__flagp, int __excepts) __THROW;

/* Determine which of subset of the exceptions specified by EXCEPTS are
currently set. */
extern int fetestexcept (int __excepts) __THROW;


/* Rounding control. */

/* Get current rounding direction. */
extern int fegetround (void) __THROW;

/* Establish the rounding direction represented by ROUND. */
extern int fesetround (int __rounding_direction) __THROW;


/* Floating-point environment. */

/* Store the current floating-point environment in the object pointed
to by ENVP. */
extern int fegetenv (fenv_t *__envp) __THROW;

/* Save the current environment in the object pointed to by ENVP, clear
exception flags and install a non-stop mode (if available) for all
exceptions. */
extern int feholdexcept (fenv_t *__envp) __THROW;

/* Establish the floating-point environment represented by the object
pointed to by ENVP. */
extern int fesetenv (__const fenv_t *__envp) __THROW;

/* Save current exceptions in temporary storage, install environment
represented by object pointed to by ENVP and raise exceptions
according to saved exceptions. */
extern int feupdateenv (__const fenv_t *__envp) __THROW;


/* Include optimization. */
#ifdef __OPTIMIZE__
# include <bits/fenvinline.h>
#endif

#ifdef __USE_GNU

/* Enable individual exceptions. Will not enable more exceptions than
EXCEPTS specifies. Returns the previous enabled exceptions if all
exceptions are successfully set, otherwise returns -1. */
extern int feenableexcept (int __excepts) __THROW;

/* Disable individual exceptions. Will not disable more exceptions than
EXCEPTS specifies. Returns the previous enabled exceptions if all
exceptions are successfully disabled, otherwise returns -1. */
extern int fedisableexcept (int __excepts) __THROW;

/* Return enabled exceptions. */
extern int fegetexcept (void) __THROW;
#endif

__END_DECLS

#endif /* fenv.h */