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Subject: Re: [Qemu-devel] [5949] target-ppc: memory load/store rework
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To: qemu-devel@nongnu.org

On 12/13/08, Stuart Brady <sdbrady@ntlworld.com> 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