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Date: Sun, 02 Aug 2015 20:12:47 +0100
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Subject: Re: [Qemu-devel] Debian 7.8.0 SPARC64 on qemu - anything i can do
	to speedup the emulation?
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To: Artyom Tarasenko <atar4qemu@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel <qemu-devel@nongnu.org>, Dennis Luehring <dl.soluz@gmx.net>, Karel Gardas <gardask@gmail.com>


Artyom Tarasenko <atar4qemu@gmail.com> writes:

> On Thu, Jul 30, 2015 at 9:12 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>>
>>
>> On 30/07/2015 05:47, Dennis Luehring wrote:
>>> so your aarch64 is just less todo for qemu - not EVERY >= 16bit memory
>>> access needs swapping or needs check for unaligned access to emulate
>>> bus-erros
>>
>> Not to mention register windows, which IIRC are the big source of pain
>> for SPARC.
>
> That's true. But then again there is an emulator called tme [1] which
> doesn't do binary translation,
> and still much faster then QEMU at least on a x86_64 host when
> emulating a sun4u machine.
>
> 1.  http://people.csail.mit.edu/fredette/tme/index.html

That does seem weird. FWIW with QuickTransit's SPARC emulation we
claimed "faster than native", e.g. we could get benchmarks that run
faster under translation on the latest Intel hardware than the fastest
production SPARC chips at the time. We did have the advantage of full FPU
translation which is an area QEMU lags a little but that doesn't seem to
be the problem here.

I notice udivx is a helper function but I guess that's to make it's
overflow and exception handling easier.

>
> Artyom

-- 
Alex Bennée