feenableexcept()
QNX SDP8.0C Library ReferenceAPIDeveloper
Unmask the specified floating-point exceptions
Synopsis:
#include <fenv.h>
int feenableexcept( int excepts );
Arguments:
- excepts
 - A bitwise OR of the flags corresponding to 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 — the result is too large to be representable
 - FE_UNDERFLOW — the result is subnormal with a loss of precision
 
 
Library:
- libm
 - The general-purpose math library.
 - libm-sve
 - 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:
- If you want only selected processes to run with the SVE version, you can include both libraries in your OS image and use the -l m or -l m-sve option to qcc to link explicitly against the appropriate one.
 - If you want all processes to use the SVE version, include libm-sve.so in your OS image and set up a symbolic link from libm.so to libm-sve.so. Use the -l m option to qcc to link against the library.
 
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 mask the exceptions, call fedisableexcept().
Unmasking a given floating-point exception means that if this exception occurs, the process will
receive a SIGFPE signal and by the default action, terminate.
For more information about this signal, see
Summary of signals
 in the System Architecture Guide.
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:
| Safety: | |
|---|---|
| Cancellation point | No | 
| Signal handler | Yes | 
| Thread | Yes | 
Page updated: 
