Install latest gcc/g++ manually

1. sudo yum -y install gcc-c++
2. sudo yum -y install gcc-c++ glibc-devel.i686
3. sudo yum -y install zip
4. Donwload and extract latest GNU gmp, ex: gmp-5.1.2.tar.gz
   Enter extracted folder
   ./configure --prefix=/usr --exec-prefix=/usr;make;sudo make install
5. Donwload and extract latest GNU mpfr, ex: mpfr-3.1.2.tar.gz
   Enter extracted folder
   ./configure;make;sudo make install
6. Donwload and extract latest GNU mpc, ex: mpc-1.0.1.tar.gz
   Enter extracted folder
   ./configure;make;sudo make install
7. Add the gmp, mpfr, mpc to ld search list:
   Add the following line to /etc/ld.so.conf.d/usr.local.conf
   

   /usr/local/lib

8. sudo ldconfig
9. Donwload and extract latest GNU gcc, ex: gcc-4.8.1.tar.gz
   Enter extracted folder
   ./configure;make;sudo make install

• Replace make with make -j8 if you have 8 CPU cores. make -j32 if you want to build with 32 threads.
  make gcc will take very long time, you should use as more cores as you can.
• The SOP is tested under gcc 4.7.x and 4.8.x