Re: [Qemu-devel] [PATCH 0/8] tcg/interpreter: Add TCG + interpreter for bytecode (virtual machine)

[David Gilbert]

On 18 September 2011 16:13, Stefan Weil <address@hidden> wrote:
> Am 18.09.2011 17:02, schrieb Mulyadi Santosa:
>>
>> Hi :)
>>
>> On Sun, Sep 18, 2011 at 02:59, Stefan Weil <address@hidden> 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.

Is it possible to dynamically switch between the two?

The two cases I'm thinking of are:
  1) Using the interpreter to execute one or two instructions in an exception
handling case
  2) Avoiding TCG code generation on the first few runs of a piece of
code that might only be init code, and only bothering with TCG for hotter
code.

Dave