[Qemu-devel] Re: [PATCH 4/4] target-xxx: Use fprintf_function (format checking)

[Paolo Bonzini]

On 11/01/2010 11:27 AM, TeLeMan wrote:
> On Mon, Nov 1, 2010 at 18:14, Paolo Bonzini<address@hidden>  wrote:
> > On 11/01/2010 10:50 AM, TeLeMan wrote:
> > > > > I think this patch is not right. Outputting 64bits data is not
> > > > > necessary on 32bits mode.
> > > >
> > > > Do you speak of 32 bit hosts or 32 bit targets?
> > >
> > > 32bit mode of x64
> >
> > There is no such thing as a 32 bit host on x64, only 64-bit hosts that
> > haven't turned on long mode.  So printing 64 bits is correct for those.
>
> If so, why the above crX is printed by 32 bits?

There are two issues.  One is what type specifier to use (and it is a 
correctness issue), the other is what width to use (and it is an 
aesthetics issue).  The patch fixes the correctness issue and makes the 
aesthetic part worse.

I agree that a better fix would be to cast to uint32_t as it is done for 
crX, but this patch is anyway better than nothing because right now DR7 
is printed incorrectly _exactly on 64-bit guests running on 32-bit mode_.

An even better fix than uint32_t would be to introduce TARGET_FMT_8lx 
(which maps to "%08"PRI_x64) so that, if for some reason the high 32-bit 
are not zero, they will be shown.

Paolo