Handling floating-point exceptions

By default, invalid operations such as division by zero, division by infinity, overflow, and underflow are ignored at run time. However, you can use the -qflttrap option to detect these types of exceptions. In addition, you can add suitable support code to your program to allow program execution to continue after an exception occurs, and to modify the results of operations causing exceptions.

Because, however, floating-point computations involving constants are usually folded at compile time, the potential exceptions that would be produced at run time will not occur. To ensure that the -qflttrap option traps all runtime floating-point exceptions, consider using the -qfloat=nofold option to suppress all compile-time folding.