Re: [Qemu-devel] RFC: Code fetch optimisation

[Fabrice Bellard <fabrice@bellard.org>]

Paul Brook wrote:
 > [...]
>>>The code itself looks ok, though I'd be surprised if it made a
>>>significant difference. We're always going to hit the fast-path TLB
>>>lookup case anyway.
>>
>>It seems that the generated code for the code fetch is much more
>>efficient than the one generated when we get when using the softmmu
>>routines. But it's true we do not get any significant performance boost.
>>As it was previously mentioned, the idea of the patch is more a 'don't
>>do unneeded things during code translation' than a great performance
>>improvment.
> 
> 
> OTOH it does make the the code more complicated. I'm agnostic about whether 
> this patch should be applied.

If it does not correct the existing x86 issues (no code segment limit 
tests and no explicit handling of code fetch exceptions in the 
translation phase in VLE case) I see no advantage in commiting it in its 
current form.

Regards,

Fabrice.