Re: [Qemu-devel] PowerPC 970/G5 suggestion/request

[Paul Brook]

On Thursday 12 August 2004 18:36, Kai Cherry wrote:
> Hi...
>
> I'd like to know what the maintainers et al would think of having the
> 970 as a different cpu like the Sparc and i386's.
>
> I ask this because it really does make a huge, measurable difference if
> or not code is targeted to that cpu. Apple has several documents on
> this, and what assembler instructions should be used, changed or
> avoided altogether, as well as notes on why stuff really needs to be
> aligned "correctly" so as not to waste huge amounts of cycles.
>
> Is this feasible? Can the code generators/re-compiler in qemu be
> modified without too much pain to generate code closer to Apple's
> recommendations at http://developer.apple.com/technotes/tn/tn2087.html
>
> Thanks in advance for any thoughts on this,

AFAIK Qemu doesn't do any optimization between the sussessive micro-ops. 
There's generally very little scope for optimization of the code of the 
individual ops, and that should already be done by gcc anyway.

Adding some sort of optimization pass over the generated code/op stream might 
speed up emulation. This isn't specific to the G5 though.  The same applies 
for pretty much all modern CPUs, including the G4.

Paul