package MyLib;

sub myfunc1
{
  my (@args) = @_;
  return myfunc2(@args, $somedata); #instead of goto &myfunc2
}

sub myfunc2
{
  my ($arg1, $arg2, $arg3, $somedata) = @_;
  if (defined $somedata) {
   .. # we got there from myfunc1
  }
}