Note that this bug seems to be present in all versions of mesa 18.1.x [1] but is fixed in mesa 18.2 [2]. [1] https://gitlab.freedesktop.org/mesa/mesa/blob/18.1/src/gallium/state_trackers/clover/core/kernel.hpp [2] https://gitlab.freedesktop.org/mesa/mesa/blob/18.2/src/gallium/state_trackers/clover/core/kernel.hpp