sub calc_tosprecedence {
    my $int_val  = shift;
    my $bit = 7;
    my @b = (0,0,0,0,0,0,0,0);
    while ($int_val > 0 ) {
        $rest = 1 if $int_val - 2**$bit >= 0 ;
        $rest = 0 if $int_val - 2**$bit < 0 ;
        $int_val = $int_val - 2**$bit if $rest;
        $b[$bit-- ] = $rest;
    }
    @b = reverse @b;
    my @prec = @b[0 .. 2];
    $sum = 0;
    @prec = reverse @prec;
    $sum += $prec[$_] * 2**$_ for (0 .. $#prec);
    return $sum
}