From mboxrd@z Thu Jan  1 00:00:00 1970
From: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Subject: Re: [PATCH 4/6] Add support for LZO-compressed kernels for ARM
Date: Fri, 7 Aug 2009 15:01:30 +0200
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To: Matthieu CASTET <matthieu.castet@parrot.com>
Cc: Alain Knaff <alain@knaff.lu>, Russell King - ARM Linux <linux@arm.linux.org.uk>, "sam@ravnborg.org" <sam@ravnborg.org>, "hpa@zytor.com" <hpa@zytor.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-embedded@vger.kernel.org" <linux-embedded@vger.kernel.org>, "akpm@linux-foundation.org" <akpm@linux-foundation.org>

On Fri, Aug 07, 2009 at 01:50:03PM +0200, Matthieu CASTET wrote :
> Albin Tonnerre a =E9crit :
> > On Fri, Aug 07, 2009 at 11:36:56AM +0200, Alain Knaff wrote :
> >> On 08/07/09 11:24, Albin Tonnerre wrote:

> >>> Regards,

> >> Could it be that the patches that remove division (zutil.h and inf=
late.c)
> >> have somehow not been applied?

> > Indeed, they've not been applied. However, I'd rather try to unders=
tand why
> > exactly this is an issue when compiling with -Os and not -O2 instea=
d of working
> > around it by removing the divisions.

> Look at the generated code.

> Arm doesn't have division instruction.
> May be at -Os gcc emit a call to the software division, but at -O2 it
> manage to optimise the division (transform it in shift, inline some
> builtin, ...).

Yes, I figured that out. What I don't get, though, is that it fails whi=
le the
software division symbol (__aeabi_uidivmod here) does seem to be provid=
ed by
libgcc.

Regards,
--=20
Albin Tonnerre, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.
http://free-electrons.com