yes command in GAS

yes.S

// gcc -c yes.S -o yes.o && gcc yes.o -o yes
    .file       "yes.S"
    .data
y:  .string "y"
    .text
    .globl      main
main:
    cmpq    $2, %rdi
    jl      .L1

    addq    $8, %rsi
    movq    (%rsi), %rbx
    jmp .L2

.L1:
    movl    $y, %edi // print $y
    call    puts
    jmp     .L1
.L2:
    movq    %rbx, %rdi
    call    puts
    jmp     .L2

out:
    //going out
    xorq    %rax, %rax
    ret