Re: [Qemu-devel] SMB for DOS ?

[Herbert Poetzl <herbert@13thfloor.at>]

On Sat, Dec 18, 2004 at 06:32:24PM +0000, Paul Brook wrote:
> > > I hope you will not forget us poor mac users. Optimizing x86 on ppc
> > > performance would make a number of people very happy, I'd say.
> >
> > performance on ppc can become very good because
> > there are much more registers available for emulating
> > the x86 stuff ...
> 
> The really slow bit tends to be MMU emulation, and more 
> host registers doesn't help here. Mapping all guest registers 
> directly onto host registers probably doesn't make all that 
> much difference as the values will tend to be in L1 
> cache anyway.

well, thought I do some benchmarks with bintrans[1] vs
qemu (i386 userspace on PPC) to see what should be possible ...

the test cadidates[2] are cli only and do cpu-bound stuff
(fibonacci numbers, the game go, and the magic square) 


            version           [A]         [B]         [C]
---------------------------------------------------------------
qemu        0.5.5           33.20      583.30     1237.48
qemu        0.6.1           18.33      476.78      872.69
bintrans    0.1             10.33      176.71      348.64
---------------------------------------------------------------
speedup                     77.4%      169.8%      150.3%


[A] i386-root/bin/fib
    time i386-user/qemu-i386 i386-root/bin/fib
    time bintrans-0.1/bintrans i386-root/bin/fib

    39088169
    Command exited with non-zero status 9

[B] i386-root/bin/go
    time i386-user/qemu-i386 i386-root/bin/go 50 21 5stone21.in
    time bintrans-0.1/bintrans i386-root/bin/go 50 21 5stone21.in

    ...
    370 W pass
    371 B pass
    Game over
    exit (0)

[C] i386-root/bin/imc
    time i386-user/qemu-i386 i386-root/bin/imc 10000 >/dev/null
    time bintrans-0.1/bintrans i386-root/bin/imc 10000 >/dev/null
    

best,
Herbert

[1] http://www.complang.tuwien.ac.at/schani/bintrans/
[2] http://www.complang.tuwien.ac.at/schani/bintrans/i386-root.tar.gz


> Paul