A report from a South Korean news outlet suggests that Samsung has teamed up with ARM. Both companies are reportedly developing custom CPU cores based on ARM's Cortex-X1 super core. It will likely debut on the upcoming Exynos 1000 chip alongside an AMD Radeon GPU.
https://www.notebookcheck.net/Samsung-has-reportedly-teamed-up-with-ARM-to-develop-custom-CPUs.485259.0.html