Load-Acquire Register Byte.
Is the 32-bit name of the general-purpose register to be transferred.
Is the 64-bit name of the general-purpose base register or stack pointer.
Load-Acquire Register Byte derives an address from a base register value, loads a byte from memory, zero-extends it and writes it to a register. The instruction also has memory ordering semantics as described in Load-Acquire, Store-Release in the ARMv8-A Architecture Reference Manual. For information about memory accesses see Load/Store addressing modes in the ARMv8-A Architecture Reference Manual.