Not as far out as the memory system, but Arm provides 'DC ZVA' (https://developer.arm.com/docs/ddi0595/b/aarch64-system-instructions/dc-zva https://developer.ar

Not as far out as the memory system, but Arm provides 'DC ZVA' (https://developer.arm.com/docs/ddi0595/b/aarch64-system-instructions/dc-zva https://developer.arm.com/docs/ddi0595/b/aarch64-system-inst...) which clears a full cache line to zero at once, which is more efficient than a pile of explicit stores. (You'll see from the description that it correctly handles the case of a watchpoint being set on the memory to be cleared, or an attempt to clear non-writeable memory -- getting those cases right would I think be a lot harder to do outside the CPU.)