[wjakob]

This analysis is somewhat dated and leaves out one important fact: nowadays, floating point arithmetic is carried out using a set of special scalar SSE instructions (and not the ancient x87 co-processor, as was done in the author's benchmark).

SSE instructions remove performance pitfalls related to infinities and NaNs. The only remaining case where slowdowns are to be expected denormals (which can be set to flush-to-zero if desired.)

In other words: it's perfectly fine to work with infinities and NaNs in your code.