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 (con-
       sult 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 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 direc-
       tion  or  a  negative  value if there is no such rounding direction macro or the current rounding direction is not deter-
       minable.

       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,  Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                FEGETROUND(3P)