fizzbuzz.asm

SECTION .data
fizz: db 'Fizz'
buzz: db 'Buzz'
num: db '00'
nl: db 0x0A

SECTION .text

global start
start:
    mov rbp, 1

    mov r8, 10
    mov r9, 3
    mov r10, 5
    mov r12, 15
    lea r13, [fizz wrt rip]
    lea r14, [buzz wrt rip]
    mov rsp, 4
    mov r15, 8

    mov rdi, 1     ; fd
.loop:
    mov rdx, 2     ; 4 bytes
    lea rsi, [num wrt rip]; string
    mov rax, rbp
    idiv r8b
    xor ax, 0x3030
    mov [1 + num wrt rip], ah
    mov [num wrt rip], al

    cmp al, 0x30

    lea rax, [1 + num wrt rip]

    cmove rdx, rdi
    cmove rsi, rax

    mov rax, rbp
    idiv r9b
    test ah, ah
    cmove rdx, rsp
    cmove rsi, r13
    mov rax, rbp
    idiv r10b
    test ah, ah
    cmove rdx, rsp
    cmove rsi, r14
    mov rax, rbp
    idiv r12b
    test ah, ah
    cmove rdx, r15
    cmove rsi, r13

    mov rax, 0x2000004 ; write
    syscall

    mov rax, 0x2000004 ; write
    lea rsi, [nl wrt rip]
    mov rdx, 1
    syscall
    inc rbp
    cmp rbp, 100
    jle .loop

    mov rax, 0x2000001 ; _exit
    mov rbx, 0     ; return value
    syscall