>> Does a CPU implementing VSX automatically support VMX/AltiVec, >> i.e. is VSX a strict superset?
> AFAIK, yes. [...] VSX is like an extention, or a superset as you put it.
That would be the best thing I heard since reading first about VSX and would fully make up for the diverging focus from AltiVec/VMX.
> I don't know if that's guaranteed to be so according to the Power ISA, > but at least on Power7 they implemented both.
Err, now that sounds like a contradiction to what you just wrote before. If POWER7 implements both VSX and AltiVec/VMX (separately), then it would mean that the latter is *not* automatically there by having the former implemented, i.e. a processor with VSX but *without* AltiVec/VMX compatibility would be technically possible (and conforming to Power ISA 2.06+).
> Though, I doubt that they would implement one without the other, to be honest.
I fear that if Power ISA 2.06+ allows to implement VSX without AltiVec/VMX compatibility then Freescale will do just that, if they adopt VSX at all that is ;-)