mkdir /usr/local/src/gcc
cd /usr/local/src/gcc
tar -xvzf ~/gcc-3.1.tar.gz
md objdir
cd objdir

time ../gcc-3.1/configure \
  --prefix=/opt/gcc31 \
  --enable-shared \
  --enable-threads=posix \
  --enable-version-specific-runtime-libs \
  --enable-languages=c,c++,java \
  --enable-fast-character

make bootstrap
make install

export PATH=/opt/gcc31/bin:$PATH
export LD_LIBRARY_PATH=/opt/gcc31/lib:$LD_LIBRARY_PATH