x86: Causes nonstandard initialization of floating-point hardware.
In addition, the -fnonstd option causes hardware traps to be enabled for floating-point overflow, division by zero, and invalid operations exceptions. These results are converted into SIGFPE signals; if the program has no SIGFPE handler, it terminates with a memory dump (unless you limit the core dump size to 0).
If -fnonstd is not specified, IEEE 754 floating-point arithmetic exceptions do not abort the program, and underflows are gradual.
-fns, -ftrap=common, Numerical Computation Guide.