Re: Super Serial Card Question?

[Eric Smith <eric@brouhaha.com>]

I wrote about how horrible the x86 instruction set is, then...
> Fortunately the 386 introduced a much cleaner 32-bit flat addressing
> model, and the Athlon 64 and Opteron [*] have done a good job of
> extending it to a 64-bit model with more general registers.

Michael J. Mahon wrote:
> By all rights, we should be entering an age of "virtual architectures",
> where both new and legacy code files are translated for execution on
> the fly, and dynamically optimized to the host architecture, whatever
> it is.

The technology (and I don't just mean IA64, but in general) isn't yet able
to do that without significant performance penalty.  It's not clear that
it will ever be possible.  If you do the translation in software, there
will always be a penalty, and if you throw enough transistors at it to
do it in hardware, it won't match the performance you could get if you
kept a fixed architecture and used those transistors to speed it up
rather than using them for dynamic translation.

That said, however, all recent Intel and AMD implementations of the
x86 architecture actually ARE doing a fair bit of dynamic translation
internally.  They're translating the x86 instructions into simpler
internal micro-ops, which are not part of the visible architecture.
(This is true dynamic translation, not just a microprogramed execution
unit.)