Re: binary portability

[Alan Cox]

Ar Iau, 2006-06-08 am 12:42 +0200, ysgrifennodd Jan Engelhardt:
> >I know that EM64T and AMD64 are ISA compatible, but there could be some 
> >differences in ELF32 between these 2 processor architectures. 
> >
> What differences? (Apart from MMXEXT and SSE2,SSE3)

There are multiple ISA differences that affect ring 0 (kernel code), but
only one nasty that hit user code with early Intel clones. The early
Intel clones didn't implement the prefetch instructions that are
mandatory in x86-64. This broke a few apps early on but they got
workarounds very fast.

If the code is built for the generic instruction set (as is the case
unless you try very hard) then it should be perfect on both.

Alan

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