fib:
  push rbp
  movrr rbp, rsp
  movsr rbp, r1
  cmpsi rbp, 0
  jg .L0
  movri eax, 0
  ret
.L0:
  cmpsi rbp, 2
  jg .L1
  movri eax, 1
  ret
.L1:
  movrs r1, rbp
  
  
  
main:
  add rsp, 16
  movsi 16(byte) rbp, 10
  movrs r1, rbp
  call fib