The general idea is to install the latest version of gcc and glibc in a user directory.  I chose /home/facultystaff2/wkim06/bin/gcc-install and home/facultystaff2/wkim06/bin/glibc-install as the final install directories for each.  Then set the LD_LIBRARY_PATH to point to those install directories.

Be aware of the directory location for these commands as they are specific to the present working directory.  Also, allow a day or two to complete everything.

The following error message appears if gcc is compiled without the required components:
<file>
[Building GCC requires GMP 4.2+, MPFR 2.3.1+ and MPC 0.8.0+.
Try the --with-gmp, --with-mpfr and/or --with-mpc options to specify
their locations.  Source code for these libraries can be found at
their respective hosting sites as well as at
ftp://gcc.gnu.org/pub/gcc/infrastructure/.  See also
http://gcc.gnu.org/install/prerequisites.html for additional info.  If
you obtained GMP, MPFR and/or MPC from a vendor distribution package,
make sure that you have installed both the libraries and the header
files.  They may be located in separate packages.]
</file>

As root, these requirements may be satisfied with the following:
  yum install mpc-devel
if mpc-devel is not found, try libmpc-devel from epel
  yum install libmpc-devel
which will install all the required components (except glibc).

As a user, mpc mpfr and gmp can be added to the source

First, download gcc-4.6.2.tar.gz (mpc, mpfr and gmp) and glibc-2.14.tar.gz in ~/bin from these locations:
  $ cd ~/bin
  $ wget ftp://ftp.gnu.org/gnu/gcc/gcc-4.6.2/gcc-4.6.2.tar.gz
  $ wget ftp://gcc.gnu.org/pub/gcc/infrastructure/mpc-0.8.1.tar.gz
  $ wget ftp://gcc.gnu.org/pub/gcc/infrastructure/mpfr-2.4.2.tar.bz2
  $ wget ftp://gcc.gnu.org/pub/gcc/infrastructure/gmp-4.3.2.tar.bz2
download glibc:
  $ wget http://ftp.gnu.org/gnu/glibc/glibc-2.14.tar.gz
untar them:
  $ tar xf gcc-4.6.2.tar.gz
  $ tar xf mpc-0.8.1.tar.gz
  $ tar xf mpfr-2.4.2.tar.bz2
  $ tar xf gmp-4.3.2.tar.bz2
  $ tar xf glibc-2.14.tar.gz
move the components to the gcc directory:
  $ mv ./mpc-0.8.1 ./gcc-4.6.2/mpc
  $ mv ./mpfr-2.4.2 ./gcc-4.6.2/mpfr
  $ mv ./gmp-4.3.2 ./gcc-4.6.2/gmp
create the object and install directories:
  $ mkdir gcc-objdir
  $ mkdir glibc-objdir
  $ mkdir gcc-install
  $ mkdir glibc-install
compile gcc with mpc, mpfr and gmp:
  $ cd ~/bin/gcc-objdir/
  $ ../gcc-4.6.2/configure --prefix=/home/facultystaff2/wkim06/bin/gcc-install/
  $ make
  $ make install
compile glibc:
  $ cd ~/bin/glibc-objdir/
  $ ../glibc-2.14/configure --prefix=/home/facultystaff2/wkim06/bin/glibc-install/
  $ make
  $ make install

To run the program:
  $ export LD_LIBRARY_PATH='/home/facultystaff2/wkim06/bin/glibc-install/lib/;/home/facultystaff2/wkim06/bin/gcc-install/lib64/'
  $ tcsh
  $ cd test-buckling
  $ ./install ...

http://gcc.gnu.org/install/

http://www.gnu.org/software/libc/