I've switched my renderer to GPU compute and get pretty terrible artifacting along with garbled denoising data.
I'm asking this here because Cycles rendering seems to be the only OpenCL workload that this happens in. Other workloads, including Luxmark, all work fine.
I'm rendering with OpenCL with a tile size of 256, and I have branched path tracing enabled.
OpenCL render (Intel denoised):
My system is an i5 6400 with a RX 480 8GB.
I'm rendering with Blender 2.83