4 ms·
> I suspect the ppc->x86 stuff was slower because x86 just doesn't have the registers. My understanding is that part of the reason the G4/5 was sort of able to
by nordsieck 4y ago
> I suspect the ppc->x86 stuff was slower because x86 just doesn't have the registers.
My understanding is that part of the reason the G4/5 was sort of able to keep up with x86 at the time was due to the heavy use of SIMD in some apps. And I doubt that Rosetta would have been able to translate that stuff into SSE (or whatever the x86 version of SIMD was at the time) on the fly.
- masklinn 4y agoRosetta actually did support Altivec. It didn't support G5 input at all though (but likely because that was considered pretty niche, as Apple only released a G5 iMac, a PowerMac, and an XServe, due to the out-of-control power and thermals of the PowerPC 970).
- bonzini 4y agoApple had a library of SIMD subroutines (IIRC Accelerate.framework) and Rosetta was able to use the x86 implementation when translating PPC applications that called it.