About controlling floating-point behavior with Numpy: I think that somewhere buried in the sources Lee Busby had us all set if we would just go through the source and stick in some macro in the right places (this was maybe 3 years ago, hence the accurate and detailed memory dump) but it was on the todo list so long it outlived the death of the todo list.
Anyway, my recollection is if we ever did it then we would have control when things like overflow happen. But we haven't. My last experience of this sort of thing was that it was completely a hardware-dependent thing, and you had to find out from each manufacturer what their routine was and how to call it or what compiler flag to use.
Well, sorry to be so imprecise but I thought it worth mentioning that some steps had been taken even if I don't remember what they were.