add.asm

section .data
    text db "number> "
    nl   db 10

section .bss
    input1 resb 1
    input2 resb 1
    tmp resb 1

section .text
    global _start

%macro addNum 2
    mov rax, [%1]
    mov rbx, [%2]
    add rax, rbx
%endmacro

%macro exit 0
    mov rax, 60
    mov rdi, 0
    syscall
%endmacro

%macro getNum 1
    ; １桁入力（数値として）
    mov rax, 0
    mov rdi, 0
    mov rsi, %1
    mov rdx, 1
    syscall
    sub byte [%1], 48
    mov rax, [%1]

    ; 改行を捨てる
    mov rax, 0
    mov rdi, 0
    mov rsi, tmp
    mov rdx, 1
    syscall
%endmacro

_start:
    call _printText
    getNum input1
    call _printText
    getNum input2
    addNum input1, input2
    call _printRAXDigit
    call _printNewLine
    exit

_printNewLine:
    mov rax, 1
    mov rdi, 1
    mov rsi, nl
    mov rdx, 1
    syscall
    ret

_printText:
    mov rax, 1
    mov rdi, 1
    mov rsi, text
    mov rdx, 8
    syscall
    ret

_printRAXDigit:
    add rax, 48
    mov byte [tmp], al
    mov rax, 1
    mov rdi, 1
    mov rsi, tmp
    mov rdx, 1
    syscall
    ret