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  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.1‐2017 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

       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 POSIX.1‐2017, <fenv.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 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 .

       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                                   2017                                    FEGETROUND(3POSIX)