4.6 Floating-Point Exceptions


4.6 Floating-Point Exceptions

The IEEE floating-point standard defines certain degenerate conditions under which the floating-point processor (or software-implemented floating-point code) should possibly notify the application software. These exceptional conditions include the following:

  • Invalid operation

  • Division by zero

  • Denormalized operand

  • Numeric overflow

  • Numeric underflow

  • Inexact result

Of these, inexact result is the least serious, because most floating calculations will produce an inexact result. A denormalized operand also isn't too serious (though this exception indicates that your calculation may be less accurate as a result of less available precision). The other exceptions indicate a more serious problem, and you shouldn't ignore them.

How the computer system notifies your application of these exceptions depends on the CPU/FPU, operating system, and programming language, so we can't really go into how one might handle these exceptions. Generally, though, you can use the exception-handling facilities in your programming language to trap these conditions as they occur in your particular environment. Note that most computer systems require that you explicitly tell them to generate a notification for these exceptional conditions; otherwise , the system will not notify you when one of the exceptional conditions exist.




Write Great Code. Understanding the Machine, Vol. 1
The Art of Assembly Language
ISBN: 1593270038
EAN: 2147483647
Year: 2003
Pages: 144
Authors: Randall Hyde

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