编译安装gcc-4.7.1

cd /usr/local/src/
wget http://ftp.gnu.org/gnu/gcc/gcc-4.7.1/gcc-4.7.1.tar.gz
tar zxf gcc-4.7.1.tar.gz
cd gcc-4.7.1
./contrib/download_prerequisites
./configure --prefix=/usr/local/gcc
make && make install
# 介个编译时间有点长，得慢慢等...