Re: [Qemu-devel] [Qemu-trivial] [PATCH 2/2] Check value for invalid negative values

[Gerd Hoffmann]

On Do, 2015-06-18 at 06:45 -0400, Frediano Ziglio wrote:
>  > On Do, 2015-06-18 at 05:58 -0400, Frediano Ziglio wrote:
> > > For the same reason there is the v >= l test.
> > > The v >= l test state that the value can be out of range so it not always 
> > > a
> > > constant in the range.
> > > Adding the v < 0 check for every invalid value. As these are executed only
> > > for logging should not be a performance penalty.
> > > I also hope the compiler is able to optimize
> > > 
> > > if (v < 0 || v >= l)
> > > 
> > > with
> > > 
> > > if ((unsigned) v >= l)
> > 
> > Just make v explicitly unsigned?
> > 
> > cheers,
> >   Gerd
> > 
> 
> Do you mean in the prototype?

Yes.

> Well, this could have side effect due to different conversions so is not a so 
> trivial patch.

What side effects?  I don't expect any for in-range values, and how
exactly we catch out-of-range values doesn't really matter ...

cheers,
  Gerd