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SystemLogic.net: Interview With Dave Taylor Of Transmeta

Mar 23, 2000, 18:42 (1 Talkback[s])

[ Thanks to Dave for this link. ]

"[Q:] Will the Code Morphing software adjust its x86 instructions to software optimized for MMX, SSE, and 3Dnow? In other words will the code morphing software be able to allow the Crusoe to emulate generic x86 only or will it be flexible as to what the best emulation technique would be for a given application?"

"[A:] We support MMX in hardware, but for now, I think it would be criminally wrong for our CPUID to advertise that it supports 3DNow or SSE. That suggests a certain floating point performance that would need specifically designed hardware to handle those instructions.

"It is pretty flexible. For instance, it might make sense for us to use MMX instructions instead of regular integer instructions if we notice a lot of integer operation parallelism and little use of the flags. We have the option of making that optimization. It would be a lot harder for a traditional CPU to do this efficiently, because it doesn't have the bird's-eye-view we do of large pieces of code.">

"For instance, when we notice a jmp instruction that always goes to the same place, or even if it just mostly goes to the same place, we often just delete the jmp and attach the destination code at the end of that translation. The net effect is not only a 0-cycle branch, but an opportunity to get even better scheduling."

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