[gentoo-user] Re: Changing compilers

[Nikos Chantziaras <realnc@gmail.com>]

On 19/03/12 07:26, Andrew Lowe wrote:
> Hi all,
> Has anyone played around with the various "better known" compilers on
> Gentoo? By "better known", I'm referring to gcc, Intel, llvm, pathscale.
> My situation is that I've just started my PhD which requires me to do
> Finite Element Analysis, FEA, and Computational Fluid Dynamics, CFD, and
> I want to find the "best" compiler for the job. Before anyone says "Why
> bother, XXX compiler is only 1 - 2% faster than gcc", in the context of
> the work I'm doing this 1 - 2% IS important.
>
> What I'm looking for is any feedback people may have on ability to
> compile the Gentoo environment, the ability to change compilers easily,
> gcc-config or flags in make.conf, as to whether the compiler/linker can
> use the libraries as compiled by gcc on a "standard" gentoo install and
> so on. Obviously there is much web trawling to be done to find what
> other people are saying as well.

You don't need to "change" compilers.  You can use whatever one you like 
to build your program.  The compiler portage uses to build its packages 
does not affect your own usage of the others.

As for the fastest one, I can only speak for Intel CPUs where Intel C++ 
gives me the fastest binaries.