To make use of all of the new features in the latest GCC versions, the latest version of binutils needs to be installed. Installation of the newer version of binutils is optional; but without it, there will be no support for new CPU instructions.
To install the latest available version of binutils using the FreeBSD ports tree, issue the following command:
# cd /usr/ports/devel/binutils && make install
The FreeBSD ports tree offers several new versions of GCC. The following example is for the stable version 4.4. However, it is possible to install previous or later development versions (e.g. lang/gcc43 or lang/gcc45).
To install one of the mentioned GCC ports, run the following command:
# cd /usr/ports/lang/gcc44 && make install