Building GCC requires GMP 4.2+, MPFR 2.3.1+ and MPC 0.8.0+

Inside the gcc directory, do this command:

./contrib/download_prerequisites

After that script, GMP, MPFR, and MPC will be ready to use. Continue with ./configure.

I had the same problem trying to install/compile GCC 4.8.1. Here is how I solved:

In Debian, just run this two commands:

apt-get install libmpc-dev
./configure

I had the same problem compiling GCC 4.9 branch.

For Red Hat and Fedora based systems, run the following command:

sudo yum install gmp gmp-devel mpfr mpfr-devel libmpc libmpc-devel

This will install the GNU multiple-precision (MP) libraries for integer, floating point, and complex numbers.