my $string  = pack "C*" => map { 32 + int rand 95 } 0..1280;

cmpthese (-1, {
    subsingle   => sub { (my $s = $string) =~ s/[^a-zA-Z0-9 _-]//g  },
    subplus     => sub { (my $s = $string) =~ s/[^a-zA-Z0-9 _-]+//g },
    tran        => sub { (my $s = $string) =~ tr/a-zA-Z0-9 _-//cd   },
    });