Section: POSIX Programmer's Manual (3P)
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.
--- raise floating-point exception
int feraiseexcept(int excepts);
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.
function shall attempt to raise the supported floating-point exceptions
represented by the
argument. The order in which these floating-point exceptions are raised is
except that if the
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.
function additionally raises the inexact floating-point exception
whenever it raises the overflow or underflow floating-point exception
If the argument is zero or if all the specified exceptions were
shall return zero. Otherwise, it shall return a non-zero value.
No errors are defined.
The following sections are informative.
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.
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.
The Base Definitions volume of POSIX.1-2017,
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
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