Re: [BUG: 2.6.26-rc3] ERROR: "____ilog2_NaN" undefined

[Adrian Bunk <bunk@kernel.org>]

On Mon, Jun 09, 2008 at 03:14:41PM -0700, Greg KH wrote:
> On Sun, Jun 08, 2008 at 02:41:12PM +0200, Mirco Tischler wrote:
> > Here's an update:
> > I've contacted the gcc folks. Here is the bugzilla entry:
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36359
> > We were able to trace the error down to usb_submit_urb() in
> > drivers/usb/core/urb.c which calls ilog2() and the gcc falsely assumes its
> > argument (urb->interval) to be zero. But as I understood they say it's the
> > kernel's fault because the code depends on correct optimization what seems a
> > little weird for me as incorrect optimization is a gcc bug IMHO. But I am not
> > an expert and maybe I've just understood something wrong because I'm not a
> > native speaker.
> 
> I'm confused how the kernel code could be at fault here.
> 
> How could it be fixed to not be at fault?

I'm quite sure this is (or was) a bug in gcc.

I'll update the gcc bug.

> thanks,
> 
> greg k-h

cu
Adrian

-- 

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