Hello Mark,

> Part of the problem is that masking FP exceptions is system wide with the
> ARM FPA/FPE. To support different exception masks for different processes
> would mean FP instructions to save and load the FP control register on every
> context switch.

FP context switch!

> I suppose one solution would be a way of setting the behaviour system wide.

Hmm, I haven't looked at the code, but what is the problem to save/restore the
exception bits when you already have to save/restore the registers anyway?
Surely the FP registers are much more stuff than the exception bits, aren't
they?

> The exception number is the key. In my book divide be zero exceptions etc
> are ok as the result is undefined.

Don't have the definition available, but I'm pretty sure that it is a
requirement for the OS to make it possible to modify the behaviour of an
application on FP exceptions.

Comments?
--
ws@TooLs.DE     (Wolfgang Solfrank, TooLs GmbH) 	+49-228-985800