* Preparing for the build

You will need the following to build the cross compiler.

    - An Unix-like environment (Windows users)
    - GCC (existing release you wish to replace)
    - G++ (if building a version of GCC >= 4.8.0)
    - GNU Make
    - GNU Bison
    - Flex
    - GNU GMP
    - GNU MPFR
    - GNU MPC
    - Texinfo
    - ISL (optional)
    - CLooG (optional)

On Ubuntu:
$ sudo apt-get install gcc g++ automake bison flex libgmp3-dev texinfo