Re: i686 quirk for AMD Geode

H. Peter Anvin
2009-11-10T18:56:37Z

On 11/10/2009 09:24 AM, Alan Cox wrote:
>>
>> In the short term, yes, of course. However, if we're going to do
>> emulation, we might as well do it right.
>
> Why is using KVM doing it right ? It sounds like its doing it slowly,
> and hideously memory inefficiently. You are solving an uninteresting
> general case problem when you just need two tiny fixups (or perhaps 3 if
> you want to fix up early x86-64 prefetch)

Why do we only need "two tiny fixups"? Where do we draw the line in
terms of ISA compatibility? One could easily argue that the Right
Thing[TM] is to be able to process any optional instruction -- otherwise
one has a very difficult place to draw a line.

Consider SSE3, for example. Why should the same concept not apply to
SSE3 instructions as to CMOV?

-hpa