Re: [Qemu-devel] [PATCH 0/6] AREG0 patches v4

[Aurelien Jarno <aurelien@aurel32.net>]

On Sat, Jan 07, 2012 at 10:24:09PM +0000, Blue Swirl wrote:
> In this version, I made basic AREG0 free load/store implementations
> for all targets. Only x86-64 is tested, others have probably problems,
> especially 64 bit guest (Sparc64 in this case) on 32 bit hosts.
> 
> I think this should be committed as a starting point if there are no
> major objections.
> 

If it is known to be broken on 32-bit hosts, I am not sure it's really
a good idea to commit these patches. It's just going to prevent all
people developing on x86 to continue testing or developing QEMU.

Also I have to say I still don't get the goal of these patch series. I
have just tried it on an x86-64 guest with a 32-bit sparc guest. It
works well, but the generated TB are slightly bigger. I have done a
quick and dirty performance test by compiling some code inside the
guests, and I get a slow down of about 0.6%, though for this kind of
performance changes, it should probably done with other methods.

Is there another goal behind this patch series beside performance?

-- 
Aurelien Jarno	                        GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net