AOCC is the AMD Optimizing C/C++ compiler suite. It is production quality, high-performance, supported compiler and tools package based on LLVM technology. More information is available at https://developer.amd.com/amd-aocc/. AMD also contributes improvements and optimizations to the LLVM project.
AMD is a contributing member of the GCC project and community and has been for 15 years. The pre-silicon support for EPYC was contributed to the GCC 6 branch with on-going improvements and optimization since.