feenableexcept()

Updated: October 26, 2022

Unmask the specified floating-point exceptions

Synopsis:

#include <fenv.h>

int feenableexcept( int excepts );

Arguments:

excepts
A bitwise OR of the flags corresponding the the exceptions that you want to unmask; zero or more of the following:
  • FE_ALL_EXCEPT — all the bits
  • FE_DENORMAL — the result of a floating-point expression is a denormalized number
  • FE_DIVBYZERO — pole error
  • FE_INEXACT — the result can't be exactly represented as a floating-point number
  • FE_INVALID — domain error
  • FE_OVERFLOW — result is too large to be representable
  • FE_UNDERFLOW — result is subnormal with a loss of precision

Library:

libm
The general-purpose math library.
libm-sve
(QNX Neutrino 7.1 or later) A library that optimizes the code for ARMv8.2 chips that have Scalable Vector Extension hardware.

Your system requirements will determine how you should work with these libraries:

Note: Compile your program with the -fno-builtin option to prevent the compiler from using a built-in version of the function.

Description:

The feenableexcept() function unmasks the specified floating-point exceptions. To unmask the exceptions, call feenableexcept().

CAUTION:
This operation doesn't work on AArch64 targets. There's a known hardware limitation that causes any unmasking of floating-point exceptions to be ignored.

Returns:

A bitmap of the exceptions that were masked before you called this function.

Classification:

BSD, QNX Neutrino

Safety:  
Cancellation point No
Interrupt handler Yes
Signal handler Yes
Thread Yes