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

       feraiseexcept — raise floating-point exception

SYNOPSIS

       #include <fenv.h>

       int feraiseexcept(int excepts);

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  feraiseexcept()  function shall attempt to raise the supported floating-point exceptions represented
       by the excepts argument. The order in which these floating-point exceptions are  raised  is  unspecified,
       except  that  if the excepts argument represents IEC 60559 valid coincident floating-point exceptions for
       atomic operations (namely overflow and inexact, or underflow and inexact),  then  overflow  or  underflow
       shall  be  raised  before  inexact.  Whether the feraiseexcept() function additionally raises the inexact
       floating-point exception whenever it  raises  the  overflow  or  underflow  floating-point  exception  is
       implementation-defined.

RETURN VALUE

       If  the  argument  is  zero  or if all the specified exceptions were successfully raised, feraiseexcept()
       shall return zero. Otherwise, it shall return a non-zero value.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The effect is intended  to  be  similar  to  that  of  floating-point  exceptions  raised  by  arithmetic
       operations. Hence, enabled traps for floating-point exceptions raised by this function are taken.

RATIONALE

       Raising  overflow  or  underflow  is allowed to also raise inexact because on some architectures the only
       practical way to raise an exception is to execute an instruction that has the exception as a side-effect.
       The function is not restricted to accept only valid coincident expressions for atomic operations, so  the
       function can be used to raise exceptions accrued over several operations.

FUTURE DIRECTIONS

       None.

SEE ALSO

       feclearexcept(), fegetexceptflag(), fetestexcept()

       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                                 FERAISEEXCEPT(3POSIX)