One way to locate where an exception occurs is to test the exception flags at various points throughout a program. However, isolating an exception precisely by this approach can require many tests and carry a significant overhead.
An easier way to determine where an exception occurs is to enable its trap. When an exception whose trap is enabled occurs, the operating system notifies the program by sending a SIGFPE signal. See the signal(5) manual page. Thus, by enabling trapping for an exception, you can determine where the exception occurs either by running under a debugger and stopping on receipt of a SIGFPE signal or by establishing a SIGFPE handler that prints the address of the instruction where the exception occurred. Note that trapping must be enabled for an exception to generate a SIGFPE signal. When trapping is disabled and an exception occurs, the corresponding flag is set and execution continues with the default result specified in Table 4–1, but no signal is delivered.