feraiseexcept(3p) — Linux manual page

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

       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(3p), fegetexceptflag(3p), fetestexcept(3p)

       The Base Definitions volume of POSIX.1‐2017, fenv.h(0p)

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(3P)

Pages that refer to this page: fenv.h(0p), feclearexcept(3p), fegetexceptflag(3p), fetestexcept(3p)

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