feraiseexcept - Linux

Overview

The feraiseexcept command in Linux raises floating-point exceptions specified by the argument(s) and performs the corresponding actions. It is commonly used for debugging numerical computations and testing floating-point hardware.

Syntax

feraiseexcept <exception>...

Arguments:

  • exception: One or more of the following floating-point exceptions:
    • FE_INVALID
    • FE_DIVBYZERO
    • FE_OVERFLOW
    • FE_UNDERFLOW
    • FE_INEXACT

Options/Flags

None

Examples

Raising a Single Exception

feraiseexcept FE_DIVBYZERO

This will raise a divide-by-zero exception.

Raising Multiple Exceptions

feraiseexcept FE_INVALID FE_DIVBYZERO

This will raise both an invalid operation exception and a divide-by-zero exception.

Example of Use in a Script

#!/bin/bash

# Raise a divide-by-zero exception
feraiseexcept FE_DIVBYZERO

# Perform a division by zero
num=10
result=$(($num / 0))

# Print the result (which will be infinite)
echo $result

Common Issues

  • Exception not raised: Ensure that the specified exception is supported on your system. Consult the documentation for your hardware architecture.
  • Unexpected behavior: Raising multiple exceptions simultaneously may lead to unpredictable results. Test each exception individually for desired behavior.

Integration

feraiseexcept can be used with other tools like gdb or a custom debugging framework to step through floating-point code and analyze the behavior of floating-point operations.

Related Commands

  • fesetexcept: Set floating-point exception flags.
  • fetestexcept: Test floating-point exception flags.
  • fpsimd: Display floating-point SIMD state.
  • gdb: A debugger for C, C++, Fortran, and others, with support for floating-point debugging.