section .text
	global ft_strlen

ft_strlen:
	test rdi, rdi
	jz err
	mov rsi, rdi
	jmp loop_start

increase_pointer:
	lea rsi, [rsi + 1]

loop_start:
	mov al, [rsi]
	test al, al
	jnz increase_pointer
end:
	sub rsi, rdi 
	mov rax, rsi
	ret

err:
	xor rax, rax
	ret