Re: Compiling applications for the new SMP processors

[Tim Prince <timothyprince at sbcglobal dot net>]

Jerin Joy wrote:
> response to an old query:
> I came across the 'mtune' option for gcc:
> http://www.dis.com/gnu/gcc/i386-and-x86-64-Options.html
>
> which allows me to specify my instruction set version. Can I achieve
> better performance in my applications (firefox, thunderbird) by
> specifying my instruction set with this option when compiling from
> source?
-mtune options allow scheduling for the processor of your choice, 
without use of any specific instructions of your processor model.
-march options can be more effective, if you don't require ability to 
run on older models.  I believe gcc-4.2, for the first time in gcc, 
includes a check to make it default to options corresponding to the 
processor where the compile is running.