Mr. Camel (a@b.c) on 12/27/11 wrote:
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>I think AMD should implement a subset of the x86 architecture in a mobile CPU that
>is targeted at tablets and smartphones.
>
>I am not completely sure what that subset would be but here are some things that I think they could drop:
>
>- most (but not all) x86 instructions involving microcode
>- string rep
>- most of the protected mode segmented memory model mess
>- transcendental fp instructions
>- etc.
>- self modifying code (i.e. don't support it)
>
>It would not seem to be too paralyzing to drop these because most mobile platforms
>(iOS, Android) are currently tailored to architectures where those things don't
>exist anyway. So moving those to this new subset of x86 would be just as easy as
>moving them to the current x86 instruction set.
>
>Also, removing these would make it easier for AMD to come up with a lower power design using fewer transistors.
>
>Intel would never do this because they are paralyzed by the
>antiquated thinking that 100% backwards compatibility is a must. This may be true
>for the traditional PC market (actually I doubt that it is true even here), but
>not for the ultra mobile market (smartphones and tablets). Perhaps Intel hopes
>that their 22 nm process technology lead will save them, but I am skeptical.
>
>Any thoughts?
>
>If this has already been suggested, then I apologize.
>
Certainly others have thought about it, including me. I see also in other threads months ago posters proposing throwing out the entire x87 unit. Simplification reduces tuning time and allows them to get a greater percentage of the chip tuned for higher performance.