section .text
global _start:
  call do_work
  mov rax, 60
  mov rdi, r13
  syscall

do_work:
  mov r14, arrrrrr
  xor r15, r15
  xor r13, r13
  jmp tst
  nop
lp:
  movsxd rax, r15d
  lea rax, [r14 + rax + 0x8]
  movsx rax, byte [rax]
  mov byte [rsp + 0x18], al
  movzx rcx, al
  and ecx, 0xf
  mov rax, r13
  add eax, ecx
  inc r15
  mov r13, rax
tst:
  movsxd rax, dword [r14]
  cmp r15, rax
  jl lp
  ret

arrrrrr:
  dd 134217728
  times 134217728 db 57h