Re: [Qemu-devel] [5949] target-ppc: memory load/store rework

[Aurelien Jarno]

On Sat, Dec 13, 2008 at 09:25:54AM +0200, Blue Swirl wrote:
> On 12/13/08, Stuart Brady <address@hidden> wrote:
> > On Mon, Dec 08, 2008 at 06:11:22PM +0000, Aurelien Jarno wrote:
> >  > - Don't swap values twice for bit-reverse load/store functions
> >  >   in little endian mode.
> >
> >  If I've read this correctly, it seems to me that we would still swap
> >  twice on little endian hosts when when emulating little endian mode or
> >  performing bit-reverse loads/stores.  Bit-reverse loads/stores under
> >  little endian emulation on a little endian host would have actually
> >  resulted in *three* byteswaps!
> >
> >  I'm not sure what the performance impact of this would be, but it's
> >  something that I've been wondering about while working on PA-RISC
> >  emulation, which will also need to provide a little endian mode.
> 
> Jocelyn sent a patch to address this. There were some (small) problems
> with it, so please read the full thread:
> http://lists.gnu.org/archive/html/qemu-devel/2007-10/msg00289.html
> 

That looks like a good start if someone wants to work again on that. The
switch to TCG probably implies some more changes.

-- 
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