Intel C++ compiler: What is highest GCC version compatibility?

I am using the latest Intel C++ compiler, icpc 15.0.1 (2014-10-23). The -gxx-name compiler option indicates to icpc what gcc libraries and language compatibility the developer desires. However, the documentation does not list the maximum version number for gcc compatibility. Is 15.0.1 compatible with gcc 4.9.x? Please provide links to documentation if available.