Re: Possibility of adding -march=native to x86

From: Adrian Bunk
Date: Thu Oct 25 2007 - 15:50:19 EST


On Thu, Oct 25, 2007 at 08:32:51PM +0100, Michael Lothian wrote:
> On 25/10/2007, Adrian Bunk <bunk@xxxxxxxxxx> wrote:
> > On Thu, Oct 25, 2007 at 08:09:56PM +0100, Michael Lothian wrote:
> > > Actually I changed the Makefile.cpu and changed the -march to native
> > > which did slightly change the size of the kernel (slightly larger I
> > > think)
> > >
> > > So what else does that option change?
> >
> > Look at arch/i386/Kconfig.cpu
> >
>
> Can you be a bit more specific?

Let's make an example:

Consider you want to compile a kernel for your P4.

The MPENTIUM4 option does not only set -march=pentium4, it also enables
several other options in arch/i386/Kconfig.cpu resulting in better
performance.

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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