Acolyte of the Butterfly
Posts: 104 from 2009/3/20
Thanks for information. My main question would be if VSX is backwards compatible to VMX/AltiVec by itself or if POWER7 supports both by having both implemented separately. Or similarily put: Does a CPU implementing VSX automatically support VMX/AltiVec, i.e. is VSX a strict superset?
AFAIK, yes. Power7 -which is the only cpu currently supporting VSX- supports VMX as well. VSX is like an extention, or a superset as you put it. I don't know if that's guaranteed to be so according to the Power ISA, but at least on Power7 they implemented both. Though, I doubt that they would implement one without the other, to be honest.