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PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
FEGETROUND(3P) POSIX Programmer's Manual FEGETROUND(3P)
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
fegetround, fesetround — get and set current rounding direction
#include <fenv.h>
int fegetround(void);
int fesetround(int round);
The functionality described on this reference page is aligned with
the ISO C standard. Any conflict between the requirements described
here and the ISO C standard is unintentional. This volume of
POSIX.1‐2008 defers to the ISO C standard.
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.
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.
No errors are defined.
The following sections are informative.
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);
/* ... */
}
None.
None.
None.
The Base Definitions volume of POSIX.1‐2008, fenv.h(0p)
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 FEGETROUND(3P)
Pages that refer to this page: fenv.h(0p), fesetround(3p)