Subject: Re: Possible bug in arm32 strongarm optimisations.
To: Chris Gilbert <firstname.lastname@example.org>
From: David Brownlee <email@example.com>
Date: 10/26/2000 16:20:08
On Thu, 26 Oct 2000, David Brownlee wrote:
> On Wed, 25 Oct 2000, Chris Gilbert wrote:
> > > You have fallen into a slight trap of the RiscPC architecture. Although
> > > the RiscPC has a StrongARM processor the memory interface does not
> > > implement 16bit (halfword) transfers. Try the following options:
> > >
> > > -march=armv3m -mtune=strongarm
> > Doh, I did go looking for docs on the strongarm flags, but there's nothing
> > the gcc man page about this (perhaps that needs to be pr'd as a docs thing?).
> > I thought I was probably doing something silly somewhere, hence asking, and
> > not pr'ing it.
> I've added a commented out
> 'makeoptions COPTS="-O2 -march=armv3m -mtune=strongarm"'
> to sys/arch/arm32/conf/RISCPC with a note that it is for StrongARM
> only CPUs. Will see if we can get a pullup for 1.5
Just a thought on this - how much of a gain would it be for
StrongARM RiscPC machines to be able to use the non halfword
StrongARM instructions? Would there be any sense in adding another
-march or similar option to gcc?
-- www.netbsd.org: A pmap for every occasion --