FEGETROUND(3P) POSIX Programmer s Manual FEGETROUND(3P)

PROLOG 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.

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 repre- sented 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 direc- tion 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 .

IEEE/The Open Group 2003 FEGETROUND(3P)