[PATCH] Set cpu explicitly in kernel compiles
trini at kernel.crashing.org
Thu May 5 14:47:37 EST 2005
On Thu, May 05, 2005 at 02:44:08PM +1000, Paul Mackerras wrote:
> Tom Rini writes:
> > So here's where the confusion comes in. You're saying that even though
> > (except .S files) no ppc32 kernel config was passing in explicit
> > -mcpu=... or similar, only CONFIG_6xx is hurt by the gcc4 biarch thingy?
> Indeed, we were never using -mcpu, and maybe we should be.
> The problem only comes up if you configure gcc4 as biarch. I can't
> imagine anyone building a biarch compiler for 4xx or 8xx. :)
I can, quite easily. Think someone like Dan doing dev from their nice
> Alan Modra tells me that gcc4 can support all the ppc families in the
> one binary, and that you can specify what cpu to use as the assumed
> default at configure time. If you specify --with-cpu=xxx at configure
> time you get scheduling for that particular cpu.
> So yes, only CONFIG_6xx is affected by biarch gcc4 assuming POWER4.
> Other families would only be affected if you were using a generic
> gcc4, which won't work at present anyway, since we don't add
Why won't it work with generic gcc4 ? Will something more than a lot of
extra nops be added?
More information about the Linuxppc-dev