What is the difference between test FPE and trap FPE?

Question

Currently I'm learning about floating point errors. In the slide I'm learning from mentions testing and trapping. This suggests that there is a clear distinction between the two. Unfortunately I haven't found what the difference is.

On the same slide there is also the question why it's not enabled by deafault.

Due to corona I'm not able to ask the lecturer, so sorry if this question is trivial.

Question:

• What is the difference between trapping and testing FPE's?
• Why is FPE testing or trapping not always enabled by default ?

Ter