These particular registers aren't part of the CPU proper anyway, so not in the register file in that sense -- they're mmio mapped, and https://securelist.com/op

These particular registers aren't part of the CPU proper anyway, so not in the register file in that sense -- they're mmio mapped, and https://securelist.com/operation-triangulation-the-last-hardware-mystery/111669/ https://securelist.com/operation-triangulation-the-last-hard... concludes that they are "a block of CoreSight MMIO debug registers for the GPU coprocessor".