Why are mpfr, mpc and gmp needed for gcc?

[Tim Prince]

  On 04/02/2012 12:35 PM, Jonathan Wakely wrote:
>   As it says there, the simplest way to install them is from your OS
> package management system.  The next best option is to use the
> contrib/download_prerequisites script in the GCC source.  Either of
> those options should ensure everything just works. The last resort,
> which usually causes problems for people who don't know what they're
> doing, is to install the support library from source.
download_prerequisites does install from source (integrated into the gcc 
build).  It saves a lot of annoyance over hunting for the right 
versions.  I've used those downloads separately to configure and make 
installations in /usr as well.

-- 
Tim Prince