They mean that they are switching to a 64-bit ARM architecture. Note that the 32->64 bit register and address size increase is by far not the only difference b

They mean that they are switching to a 64-bit ARM architecture. Note that the 32->64 bit register and address size increase is by far not the only difference between 32-bit ARM and 64-bit ARM. Aarchv8 (64-bit arm) is effectively a complete clean redesign of the ISA, designed to be modern, fast, and only maintain some backwards compatibility, discarding many signature features of ARM that no longer make sense. Such as predication of everything and free shifts in every instruction. 64-bit ARM should be significantly faster, at least once the compilers catch up.