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