section .bss
	buffer resb 20

section .text
	global itoa

itoa:
	mov rax, rdi
	mov rsi, buffer + 19
	mov byte [rsi], 0
	dec rsi
.loop:
	xor rdx, rdx
	mov rcx, 10
	div rcx
	add dl, '0'
	mov [rsi], dl
	dec rsi
	test rax, rax
	jnz .loop
	inc rsi
	mov rax, rsi
	ret