section .data
;;;  static
hellow:  db "Hello World!"
hellow_len:          equ $ - hellow
        section .bss

        common  stdinbuf        1048576:16
        common  stdinbuf_size   8:8
        common  stdinbuf_seek   8:8
        common  stdoutbuf       1048576:16
        common  stdoutbuf_size  8:8

        section .text
        global _start
_start:
        call    readstdin
        call    setupstdout

        call    nextInt
        mov     r10,    rax
        call    nextInt
        add     r10,    rax
        mov     rdi,    r10
        call    putInt
        call    newLine

        call    writestdout
        mov     rax,    60
        mov     rdi,    0
        syscall
        ret

readstdin:
        mov     rax,    0
        mov     rdi,    0
        mov     rsi,    stdinbuf
        mov     rdx,    1048576
        syscall
        mov     [stdinbuf_size],        rax
        mov     rax,    0
        mov     [stdinbuf_seek],        rax
        ret

setupstdout:
        mov     rax,    0
        mov     [stdoutbuf_size], rax
        ret

writestdout:
        mov     rax,    1
        mov     rdi,    1
        mov     rsi,    stdoutbuf
        mov     rdx,    [stdoutbuf_size]
        syscall
        ret

;;; ; rdi : dest
;;; ; rsi : src
;;; ; rdx : size
strncpy:
        cmp     rdx,    0
        jne     strncpy_L1
        ret
strncpy_L1:
        mov     al,    [rsi]
        mov     [rdi],  al
        add     rsi,    1
        add     rdi,    1
        sub     rdx,    1
        jne     strncpy_L1
        ret

;;; ; dil char
putChar:
        mov     rax,    stdoutbuf
        add     rax,    [stdoutbuf_size]
        mov     [rax],  dil
        mov     rax,    [stdoutbuf_size]
        add     rax,    1
        mov     [stdoutbuf_size],       rax
        ret

;;; ; rdi str
;;; ; rsi size
putStr:
        cmp     rsi,    0
        jne     putStr_L1
        ret
putStr_L1:
        mov     rax,    stdoutbuf
        add     rax,    [stdoutbuf_size]
        mov     rdx,    [stdoutbuf_size]
        add     rdx,    rsi
        mov     [stdoutbuf_size], rdx
putStr_L2:
        mov     dl,     [rdi]
        mov     [rax],  dl
        add     rax,    1
        add     rdi,    1
        sub     rsi,    1
        jne     putStr_L2
        ret

;;; ; rdi str
;;; ; rsi size
putStrLn:
        push    rdi
        push    rsi
        call    putStr
        pop     rsi
        pop     rdi
        mov     dil,    10
        call    putChar
        ret

;;; ; return 8bit char
nextChar:
        mov     rdi,    stdinbuf
        add     rdi,    [stdinbuf_seek]
        mov     al,     [rdi]
        mov     rdi,    [stdinbuf_seek]
        add     rdi,    1
        mov     [stdinbuf_seek],        rdi
        ret

;;; ; return (64bit unsigned int)
nextInt:
        mov     rax,    0
nextInt_L1:
        push    rax
        call    nextChar
        mov     dil,     al
        pop     rax
        cmp     dil,     48
        jb      nextInt_L2
        cmp     dil,     57
        ja      nextInt_L2
        mov     rsi,    10
        mul     rsi
        movzx   rcx,    dil
        sub     rcx,    48
        add     rax,    rcx
        jmp     nextInt_L1
nextInt_L2:
        ret

;;; ; rdi 64bit int
putInt:
        cmp     rdi,    0
        jne     putInt_L0
        mov     dil,    48
        call    putChar
        ret
putInt_L0:      
        mov     rcx,    0
        mov     rax,    rdi
putInt_L1:
        cmp     rax,    0
        je      putInt_L2
        mov     rdx,    0
        mov     rsi,    10
        div     rsi
        push    rdx
        add     rcx,    1
        jmp     putInt_L1
putInt_L2:
        cmp     rcx,    0
        je      putInt_L3
        sub     rcx,    1
        pop     rdi
        add     rdi,    48
        push    rcx
        call    putChar
        pop     rcx
        jmp     putInt_L2
putInt_L3:
        ret

newLine:
        mov     dil,    10
        call    putChar
        ret