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Date: Sun, 18 Sep 2011 17:13:54 +0200
From: Stefan Weil <weil@mail.berlios.de>
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Subject: Re: [Qemu-devel] [PATCH 0/8] tcg/interpreter: Add TCG + interpreter
 for bytecode (virtual machine)
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To: Mulyadi Santosa <mulyadi.santosa@gmail.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>

Am 18.09.2011 17:02, schrieb Mulyadi Santosa:
> Hi :)
>
> On Sun, Sep 18, 2011 at 02:59, Stefan Weil <weil@mail.berlios.de> wrote:
>> Hello,
>>
>> these patches add a new code generator (TCG target) to qemu.
>
> I personally congrats you for your hard work. So, here's a question
> from who are not so keen with Qemu internals: what is the biggest
> advantage of using TCI instead of directly using TCG?

TCG with native code support is much faster (6x to 10x),
so for emulation on a supported host, TCI has no advantage
for normal users.

Its primary purpose was support of new hosts without a native
TCG.

In addition, it's easier to trace TCG operations in TCI
than in generated native code, so TCI is really good to
examine code, to test new TCG opcodes, to make statistics
(I did some with Valgrind which now now longer works
thanks to coroutines), to test the influence of TCG parameters
like the number of available registers. I'm sure there are
even more interesting applications for which TCI could be
used.

Cheers,
Stefan