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Author Topic: Opensource PPC emulation for Linux x86  (Read 6938 times)

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Offline KarlosTopic starter

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Opensource PPC emulation for Linux x86
« on: December 18, 2003, 12:39:59 AM »
Hi,

I'm just posting this here in case I botched the news submission ;-)

Anyhow, some feller has apparently got a working PowerPC emulation for linux x86, discussion here, called SheepShaver (:lol:).
From what I gather, it is a JIT 32-bit PPC emulation and is able to boot MacOS 8.6..

The sourcecode is available here...

I expect the mac community is about to be cleaved in two ;-)

-edit-

I wonder what the AROS x86 crowd will make of it?
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Offline KarlosTopic starter

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Re: Opensource PPC emulation for Linux x86
« Reply #1 on: December 18, 2003, 01:02:33 AM »
I dint really check up fully. I guess this isnt that new news then :-)

-edit-

You sure? I keep seeing references to someone called Gwenole...
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Offline KarlosTopic starter

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Re: Opensource PPC emulation for Linux x86
« Reply #2 on: December 18, 2003, 02:05:49 AM »
@Kenny - Its a JIT, not an interpreter ;-)

Whilst I am sure the G5 and probably even G3 will outclass it just now, it remains to be seen what an aggressively optimised x86 implementation for the latest x86 processors would be capable of. Just look at emulated 680x0 under Amithlon for example.

In the end it comes down to price. You might not get G5 performance for several years but you might get something at a better price/preformance ratio.
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Offline KarlosTopic starter

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Re: Opensource PPC emulation for Linux x86
« Reply #3 on: December 18, 2003, 05:39:23 AM »
Whilst I am, the first to point out that from a coding model, the x86 sucks like hell, the whole register issue is a lot more complex than "it doesnt have enough registers to emulate it well"

Internally, the differences between RISC and CISC blurred years ago.

In fact, most recent x86 chips have stupid numbers of registers, existing as 'shadows' of the main register file. This is like the rename register concept in PPC.

Nobody really thought that AMD and the like get the performance they do by actually relying on a 4 register user model, did they? :lol:

As for performance, Kenny is right that 'normal' benchmarks are pretty useless way of determining JIT performance. Quite where he got 35% from is hence also dubious - one application is hardly representitive.

All I am saying is that it is the start. The whole x86 is driven by competition far more fierce than the PPC platform.

It could be that in a few years, emulation of current generation of PPC chips on whatever lunatic clockspeed x86 room heaters are out by then is faster and yet still cheaper...
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Offline KarlosTopic starter

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Re: Opensource PPC emulation for Linux x86
« Reply #4 on: December 18, 2003, 06:05:10 AM »
Quote

Rodney wrote:
It's still going to be slow isnt it? I mean, you'r not going to be able to run you'r even near what they're support to run at. That is, i assume its slow. Look at 68k emulation, thats not too bad, but thats mainly because everyone has low expectations because the 68k CPU's are very slow compared to x86 CPU but the PPC is on par basicly.


Well, thats subjective. A friends AthlonXP 2800 system runs 680x0 code about 15-20x faster than his CSMK III 68060 @ 50MHz if programs like photogenics, Cinema4D, lame, Quake1 and what not are anything to go by.

I can tell you, thats not slow, not even by PPC standards. His 680x0 emulation is certianly considerably faster than my BlizzPPC for raw number crunching.

If this PPC emulation can be optimised at least as far as that 680x0 JIT, it would doubltess outperform any 60x on that hardware.

As it goes, It's very early days and I expect the emulation is pretty slow for now.

As for its potential, who knows?
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Offline KarlosTopic starter

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Re: Opensource PPC emulation for Linux x86
« Reply #5 on: December 18, 2003, 07:04:00 AM »
@Argo

:lol: Just followed the second link. Not the cheeriest looking feller, is he?
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Offline KarlosTopic starter

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Re: Opensource PPC emulation for Linux x86
« Reply #6 on: December 18, 2003, 09:00:29 AM »
I'm pretty sure it doesnt do MMU emulation ;-)
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Offline KarlosTopic starter

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Re: Opensource PPC emulation for Linux x86
« Reply #7 on: December 18, 2003, 05:34:07 PM »
Quote

lempkee wrote:
sounds too stupid to be true...


It looks real enough from the source code...
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Offline KarlosTopic starter

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Re: Opensource PPC emulation for Linux x86
« Reply #8 on: December 18, 2003, 08:54:09 PM »
@bloodline

That's an extremely tall order. Still, not long ago I said that about basic user model PPC emulation anyway, so you never know ;-)
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