segment .data a dq 175 b dq 4097 sum dq 0 diff dq 0 segment .text global main main: mov rax, [a] ; mov a (175) into rax mov rbx, rax ; mov rax to rbx add rax, [b] ; add b to rax mov [sum], rax ; save the sum sub rbx, [b] ; subtract b from rax mov [diff], rbx xor rax, rax ret