Re: [hatari-devel] ImPerfect Falcon 512b demo?

[Toni Wilen <twilen@xxxxxxxxxx>]

>> Host mode can't work with FPSP.
> 
> Are you sure about that? I guess with "host mode" you mean using the normal 
> math library of the host for FPU instructions. But the check whether a certain 
> FPU instruction is supported or not should be done before that, so illegal 
> instruction should still be thrown. Only other FPU exceptions like divide zero 
> etc. might not work, but they are masked by default, and i've not yet seen any 
> program than unmasks them just to catch the exceptions.

I don't remember details anymore but there are situations where FPSP
expects FPU exceptions from its internal operations (underflow/overflow
which are unmaskable in 68040+) and returns wrong results if behavior
was not exactly right. Same problem with normally rarely used FPU status
flags, they need to be exactly right which isn't possible in host mode.