Re: [Qemu-devel] patch for qemu with newer gcc-3.4.x (support repz retq optimization for amd processors correctly)

["John R. Hogerhuis" <jhoger@pobox.com>]

On Thu, 2005-11-10 at 01:44 +0000, Jamie Lokier wrote:
> > 
> > The use of gcc to generate the back end in QEMU's early days was a 
> > clever way to get the project up and running quickly.  But surely
> > now it would be better to transition to a handwritten backend, so
> 
> It should be trivial to take the _currently_ generated GCC code for
> all the architectures QEMU is commonly built on, and just distribute
> that code with the QEMU source.
> 
> Then it would be independent of future changes to GCC.
> 
> I understand a handwritten backend is already being written.  But
> until a proper one is done, wouldn't that serve as a useful stopgap?
> 
> -- Jamie
> 


I you poke around in the archives, this idea was raised before (by me,
maybe). I think it would work, but I didn't hear a lot of enthusiasm for
it. I think it would also open the door for hand-tweaking critical areas
for performance.

Paul Brook has another take, and the benefit of his is you can look at
real life code to see how it will work.

-- John.