Hello World in GNU Assembly

helloworld.s

.data                                                                                                                                        [5/1908]
hellostr:
.string "Hello World"

.text
.global main
main:
    pushq   %rbp
    movq    %rsp, %rbp

print_word:
    movq    $hellostr, %rdi
    call    puts

print_int:
    movq    $123, %rax  #print 123

    movq    %rsp, %rdi  #save current stack address as rdi
    push    $0          #make room for result string (for 8 bytes = 8 digits)
    dec     %rdi        #first byte above stack
    movb    $0, (%rdi)  #store string terminator at this location
    movb    $10, %bl    #set divider at 10 for each digit

next_digit:
    idivb   %bl         # %ax/%bl ==> %al (quotient), %ah (reminder) 
    add     $0x30, %ah  # convert reminder to ascii by adding with '0'
    dec     %rdi        # move back one byte
    movb    %ah, (%rdi) # store the digit
    xor     %ah, %ah    # remove the reminder
    test    %al, %al    # test if quotient is 0
    jnz     next_digit  # do until %rax==0

    call    puts        # done converting, call puts

    pop     %rax        # clear the empty space
    movq    $0, %rax

    leave
    ret