NAME
fegetround, fesetround - get and set current rounding direction
SYNOPSIS
#include <fenv.h>
int fegetround(void);
int fesetround(int round);
DESCRIPTION
The fegetround() function shall get the current rounding direction.
The fesetround() function shall establish the rounding direction
represented by its argument round. If the argument is not equal to the
value of a rounding direction macro, the rounding direction is not
changed.
RETURN VALUE
The fegetround() function shall return the value of the rounding
direction macro representing the current rounding direction or a
negative value if there is no such rounding direction macro or the
current rounding direction is not determinable.
The fesetround() function shall return a zero value if and only if the
requested rounding direction was established.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
The following example saves, sets, and restores the rounding direction,
reporting an error and aborting if setting the rounding direction
fails:
#include <fenv.h>
#include <assert.h>
void f(int round_dir)
{
#pragma STDC FENV_ACCESS ON
int save_round;
int setround_ok;
save_round = fegetround();
setround_ok = fesetround(round_dir);
assert(setround_ok == 0);
/* ... */
fesetround(save_round);
/* ... */
}
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
The Base Definitions volume of IEEE Std 1003.1-2001, <fenv.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .