def is_asm(l):
  """Returns whether a line should be considered to be an instruction."""
  l = l.strip()
  # Empty lines
  if l == '':
    return False
  # Comments
  if l.startswith('#'):
    return False
  # Assembly Macros
  if l.startswith('.'):
    return False
  # Label
  if l.endswith(':'):
    return False
  return True