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SubjectRe: test13-pre5
On Sun, Dec 31, 2000 at 09:27:23AM -0800, Linus Torvalds wrote:
>
>
> On Sun, 31 Dec 2000, Andi Kleen wrote:
> >
> > Sounds good. It could also be controlled by a CONFIG_SPACE_EFFICIENT for
> > embedded systems, where you could trade a bit of CPU for less memory overhead
> > even on systems where u8 is slow and atomicity doesn't come into play
> > because it's UP anyways.
>
> UP has nothing to do with it.
>
> The alpha systems I remember this problem on were all SMP.
[...]

I just checked all architecture manuals I could lay my hands on
(sparcv9, ppc32, mips r4400, parisc 1.1, alpha, sh is somewhere in
storage but as I remember it has it too)
and they all seem to have at least store byte and mostly store
half words instructions.

>
> Imagine an architecture where you need to do a
>
> load_32()
> mask-and-insert-byte
> store_32()

iirc the Alpha guys found out that they couldn't drive half of the
available devices without byte store, and since then nobody has
repeated that mistake @)


>
> I don't think it's a good diea.

I don't see it. Just define x8 to u32 on old alpha and let most other architectures
be happy.


-Andi

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