[zurn]

Denormals are part of IEEE fp. If your implementation is too slow, you can often trade correctness for speed by turning them off in the C/C++ runtimes.

They're also a sign you're skirting on the limits of FP precision (or worse) so a bit of numerical analysis might still be a good idea...

[malkia]

You cannot simply turned them off everywhere. On certain platforms they are produced always, and nothing can be done, but openly deal with them (by expecting them to happen).