gistfile1.pl

use Benchmark 'cmpthese';

my $tagname = shift;

cmpthese(
    1_000_000,
    {
        regexp => sub { regexp($tagname) },
        lc_eq  => sub { lc_eq($tagname) },
        regexp_subst => sub { regexp_subst($tagname) },
        lc_eq_subst  => sub { lc_eq_subst($tagname) },
    }
);

sub regexp {
    return ( $_[0] =~ /^(?:blockquote|q)$/i );
}

sub regexp_subst {
    my $tag = shift;
    return ( $tag =~ /^(?:blockquote|q)$/i );
}

sub lc_eq {
    return ( lc($_[0]) eq 'blockquote' || lc($_[0]) eq 'q' );
}

sub lc_eq_subst {
    my $lt = lc($_[0]);
    return ( $lt eq 'blockquote' || $lt eq 'q' );
}

__END__

# textarea

                  Rate regexp_subst       regexp  lc_eq_subst        lc_eq
regexp_subst 1694915/s           --         -22%         -24%         -32%
regexp       2173913/s          28%           --          -2%         -13%
lc_eq_subst  2222222/s          31%           2%           --         -11%
lc_eq        2500000/s          47%          15%          12%           --


# blockquote

                  Rate regexp_subst       regexp  lc_eq_subst        lc_eq
regexp_subst 1639344/s           --         -21%         -34%         -48%
regexp       2083333/s          27%           --         -17%         -33%
lc_eq_subst  2500000/s          52%          20%           --         -20%
lc_eq        3125000/s          91%          50%          25%           --