Re: [Devil-linux-develop] Suggestion for better compiling.

[John K. <jk...@sa...>]

	The kernel is only being compiled for different CPU's, the applications
are being compiled for 486.

	Reason, the tool chain in the LFS system was built for 486 compilation
and this will be the default -march. To fix this all build scripts will
have to add to the gcc options a -march=<CPU>. Adding this would be
easier during ./configure. eg.  CFLAGS= -march=686; ./configure
<options>.  And of course it would be very nice if the 686 came from a
shell variable set by the DL config file.

	Now I could still be wrong about this, and someone coming back and
calling me a moron ;-), but one thing that could be happening is an
environment variable could be set that sets the default -march for
gcc??? Maybe Heiko would know the answer to this? But in all the gnu
toolchains that I've built I've never seen documented that the default
arch can be controled by an enviornment variable, but the gcc manual is
pretty thick.


	Now a comment that could make this entire discussion mute is compiling
the kernel from a 486 to a 686 makes a huge difference on the system.
But what are you really gaining by changing the applications from a 486
to 686 compiles??? 


On Tue, 2003-06-17 at 18:18, Heiko Zuerker wrote:
> Bruce Smith wrote:
> >>>>Take a look at scripts/prepare and search for "uname" ( without the
> >>>
> >>>quotes
> >>>
> >>>>*lol*).  The complete DL System is build for the specific CPU.
> >>>
> >>>Are you sure it's working?  I was watching openssl & glibc both compile
> >>>on my screen, and I never say anything that looked like:  -march i686
> >>>or any gcc parameter containing "686" (except for the kernel).
> >>
> >>Hmmm.....checking...checking.....checking....executing: ./scripts/build.sh
> >>build opt=openssh
> >>Ok, the host-type and build-system-type in the configure part is correct,
> >>but I don't see any -march=686 either.
> >>Question: doesn't gcc use the architecture it was compiled for, when you
> >>don't specify anything?
> > 
> > 
> > I don't know.  I'm far from being a gcc expert.
> 
> same here
> 
> >>I'm getting a bit confused now....
> > 
> > 
> > Welcome to the club!  :-)
> > 
> > I've been reading the gcc man page, looking at gcc.gnu.org docs, and
> > searching the newsgroups.
> > 
> > The most useful thing I found so far is "gcc -v" tells what "spec" file
> > it uses for default options.  I looked at that file, but all the fancy
> > substitution stuff is over my head.
> > 
> > It may be using i686 optimization (in my case), but I don't know how to
> > confirm or deny it.
> 
> Let's hope somebody on this list has the answer to this.
> 
> cya
>    Heiko
> 
> 
> 
> -------------------------------------------------------
> This SF.Net email is sponsored by: INetU
> Attention Web Developers & Consultants: Become An INetU Hosting Partner.
> Refer Dedicated Servers. We Manage Them. You Get 10% Monthly Commission!
> INetU Dedicated Managed Hosting http://www.inetu.net/partner/index.php
> _______________________________________________
> Devil-linux-develop mailing list
> Dev...@li...
> https://lists.sourceforge.net/lists/listinfo/devil-linux-develop
-- 
John Kiss <jk...@sa...>