; /usr/local/bin/nasm -f macho64 sum.asm && ld -macosx_version_min 10.7.0 -lSystem -o sum sum.o && ./sum global start section .text extern _printf extern _exit start: ; Calculations mov rax, 1 push rax mov rax, 2 pop rbx add rax, rbx push rax mov rax, 3 pop rbx add rax, rbx push rax mov rax, 9 pop rbx add rax, rbx ; Output mov rsi, rax ; Move result to output mov qword rax, 0 ;A zero in rax indicates that printf receives standard lea rdi, [rel message] call _printf mov qword rax, 0 call _exit section .data message: db "Register %i", 10, 0 .len: equ $ - message