Something like this
sub jump # this is basically all psuedocode the real sub is more complicated but this is the gist
{
      if($condition == TRUE)
      {
           $jmptaken = 1;
      }
      else
      {
            $jmptaken = 0;
       }
}



sub loopstuff
{
    do
    {
         &DoAllTheThing!!();  #since the loop/jmp is pushed to the array anyway, it will be run in the &doallthethings
     }until($jmptaken == 0)
}