Messages in this thread |  | | Date | Mon, 10 Mar 2008 22:02:01 +0000 (GMT) | From | Hugh Dickins <> | Subject | Re: P6 NOPs again: MPSC? |
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On Mon, 10 Mar 2008, H. Peter Anvin wrote: > Hugh Dickins wrote: > > > > I'm suspecting that the patch below is actually wrong, and that it's > > really the "(X86_64 || !X86_GENERIC) &&" which should be changed; > > but very unsure of my ground and what's right for CPU_GENERIC - > > the 32/64 heritage of x86/Kconfig.cpu rather confuses me. > > X86_64 && !X86_GENERIC comes from not wanting to be a compatibility issue when > compiling for generic CPUs. There are some 32-bit otherwise i686-compatible > chips (from VIA and Transmeta) which don't have these NOPs.
Yup, I realized that (with || in place of &&): I meant that perhaps it was supposed to say X86_64 || (!X86_GENERIC && (M686 || ....)) since quite a lot of other options there have "|| X86_64" to cover all the 64-bit possibilities at once i.e. is it only MPSC that needs to be added, or both MPSC and CPU_GENERIC?
(But I've lost my way around here. A good example of the 32/64 confusion is how one has to remember that X86_GENERIC is peculiar to 32-bit, and CPU_GENERIC peculiar to 64-bit. And CPU_GENERIC is understandably an alternative to the specific 64-bit models, but X86_GENERIC is strangely in addition to the specific 32-bit models.)
Hugh
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