Re: [gentoo-dev] ICC Profile

["Sébastien Fabbro" <bicatali@gentoo.org>]

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On Thursday July 17, Adam Stylinski wrote:

> Pro's:
> 
> 1.) Bloody fast machine code.  Intel obfuscates their architecture
> but they give back to the community as much as possible to make their
> hardware marketable toward the open source sysadmin, developer, etc
> etc.  Their drivers are open and they develop for the kernel
> constantly.  This cooperation leads me to believe that they would
> assist a team of developers in making 100% icc compatible code.  

Gentoo is not supported from Intel, and they had not plans doing so. As
of October 2007, I asked their Software channel whether Gentoo
users have similar support as RedHat or SUSE users and the answer was:

"No, we have no current plans to support Gentoo. Also, Gentoo is NOT a
derivative of a Linux we do support.  My understanding is that it is
independently derived from Kernel.org.  Thus it is less likely to work
than a distro which is a derivative of a supported distribution.

Meanwhile, Debian/Ubuntu got support, so things might change if
Gentoo re-becomes/remains popular. Any Intel dev reading this list,
please contact us.

And as Luca mentioned, having sunstudio, xlc (is this one free?) or llvm
would not make Intel a privileged case for Gentoo.


> 2.) Bloody fast compilation time.  In my experience the compiler
> works much faster even with heavy optimization.  

I don't experience this that much, but I really don't use it much
either. Would be nice to have benchmarks here.

 
> 4.) will project gentoo toward the power user more, helps the gentoo
> image, and overall will make linux a more professional operating
> system (and a quite competitive alternative to something like a
> SPARC+Solaris configuration).  This would also make cluster farms and
> science application more respectful toward the gentoo community.  The
> academic and research world already uses ICC to compile their apps
> for the sake of speed.  The interprocedural optimizations for both
> the fortran and c/c++ compilers make it a must.  

I would be careful about this, and this needs benchmarks, especially
with gcc > 4.3. By default icc flags are fairly agressive. For example,
for many scientific applications, you don't want a simple -O2 where you
loose floating point precision. Add -mp or -mp1 to your icc flags, add
some decent gcc flags, and improvement over gcc is much smaller.
 
> 5.) It's free, albeit a commercial product.  As gentoo is entirely
> non-profit, there is no restriction when it comes to licensing.  The
> binaries won't be sold for the intel-compiled livecd, and the
> compiler itself with a fetch restriction allows the user to legally
> register for their free non-commercial license.    

Again, as long as you're not being compensated for doing it (for Gentoo
I'm not).

In summary, I'm completely in favor of trying projects like this, but
first, this needs a few benchmarks before going further.


- -- 
Sébastien
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