PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

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

PROLOG         top

       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         top

       fegetround, fesetround — get and set current rounding direction

SYNOPSIS         top

       #include <fenv.h>
       int fegetround(void);
       int fesetround(int round);

DESCRIPTION         top

       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.

RETURN VALUE         top

       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         top

       No errors are defined.
       The following sections are informative.

EXAMPLES         top

       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         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       The Base Definitions volume of POSIX.1‐2008, fenv.h(0p)

COPYRIGHT         top

       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)