The long: Rate ikegami2A mrm_l ikegami1 ikegami3 ikegami2x ikegami2 JavaFan kvale ccn mrm_s orig GF ikegami2A 693/s -- -60% -66% -69% -76% -76% -84% -84% -85% -89% -90% -90% mrm_l 1717/s 148% -- -15% -24% -40% -42% -61% -62% -63% -72% -74% -75% ikegami1 2023/s 192% 18% -- -10% -29% -31% -54% -55% -56% -67% -70% -71% ikegami3 2256/s 226% 31% 12% -- -21% -23% -49% -49% -51% -63% -66% -67% ikegami2x 2856/s 312% 66% 41% 27% -- -3% -36% -36% -38% -53% -57% -59% ikegami2 2940/s 324% 71% 45% 30% 3% -- -34% -34% -36% -52% -56% -58% JavaFan 4443/s 542% 159% 120% 97% 56% 51% -- -1% -3% -27% -34% -36% kvale 4467/s 545% 160% 121% 98% 56% 52% 1% -- -2% -27% -33% -35% ccn 4581/s 562% 167% 127% 103% 60% 56% 3% 3% -- -25% -32% -34% mrm_s 6087/s 779% 254% 201% 170% 113% 107% 37% 36% 33% -- -9% -12% orig 6689/s 866% 290% 231% 196% 134% 128% 51% 50% 46% 10% -- -3% GF 6919/s 899% 303% 242% 207% 142% 135% 56% 55% 51% 14% 3% -- the short: Rate ikegami2x ikegami2A ikegami1 ikegami3 JavaFan mrm_l kvale ccn ikegami2 mrm_s GF orig ikegami2x 54274/s -- -26% -64% -64% -71% -71% -71% -75% -78% -78% -78% -84% ikegami2A 73135/s 35% -- -52% -52% -61% -61% -61% -66% -70% -70% -71% -79% ikegami1 151690/s 179% 107% -- -0% -18% -19% -19% -30% -38% -38% -39% -56% ikegami3 151690/s 179% 107% 0% -- -18% -19% -19% -30% -38% -38% -39% -56% JavaFan 185391/s 242% 153% 22% 22% -- -1% -2% -15% -24% -25% -26% -46% mrm_l 188182/s 247% 157% 24% 24% 2% -- -0% -13% -22% -24% -25% -46% kvale 188359/s 247% 158% 24% 24% 2% 0% -- -13% -22% -24% -25% -46% ccn 217080/s 300% 197% 43% 43% 17% 15% 15% -- -11% -12% -13% -37% ikegami2 242794/s 347% 232% 60% 60% 31% 29% 29% 12% -- -1% -3% -30% mrm_s 246469/s 354% 237% 62% 62% 33% 31% 31% 14% 2% -- -1% -29% GF 249581/s 360% 241% 65% 65% 35% 33% 33% 15% 3% 1% -- -28% orig 346085/s 538% 373% 128% 128% 87% 84% 84% 59% 43% 40% 39% -- and the check: orig: 333444 ccn: 333444 kvale: 333444 JavaFan: 333444 GF: 333444 ikegami1: 3334444 ikegami2: 333444 ikegami2A: 333444 ikegami2x: 333444 ikegami3: 3334444 mrm_s_const: 3334444 mrm_l_const: 3334444 ##

##

use warnings;
use strict;
use Benchmark qw(cmpthese);

my ($ikegamiRe1) = map qr/$_/, join '|', map "(?<=${_}{3})$_+", map quotemeta,
    1 .. 9;
my ($ikegamiReA) = map qr/$_/, join '|', map "(?<=${_}{3})$_+", map quotemeta,
    (1 .. 9, 'a' .. 'z', 'A' .. 'Z');
my $str = join '', map { $_ x $_ } 1 .. 9;
$str = $str x 20;

print "The long:\n";

cmpthese (
    -1,
    {
        orig    => \&orig,
        ccn     => \&ccn,
        kvale   => \&kvale,
        JavaFan => \&JavaFan,
        GF      => \&GF,
        ikegami1 => \&ikegami1,
        ikegami2 => \&ikegami2,
        ikegami2A => \&ikegami2A,
        ikegami2x => \&ikegami2x,
        ikegami3 => \&ikegami3,
        mrm_s => \&mrm_s_const,
        mrm_l => \&mrm_l_const,
    }
    );

$str = substr $str, 3, 7;
print "the short:\n";

cmpthese (
    -1,
    {
        orig    => \&orig,
        ccn     => \&ccn,
        kvale   => \&kvale,
        JavaFan => \&JavaFan,
        GF      => \&GF,
        ikegami1 => \&ikegami1,
        ikegami2 => \&ikegami2,
        ikegami2A => \&ikegami2A,
        ikegami2x => \&ikegami2x,
        ikegami3 => \&ikegami3,
        mrm_s => \&mrm_s_const,
        mrm_l => \&mrm_l_const,
    }
    );

print "and the check:\n";

for my $func (qw(
        orig ccn kvale JavaFan GF ikegami1 ikegami2 ikegami2A ikegami2x ikegami3
        mrm_s_const mrm_l_const
    )) {
    my $funcRef = \&{"$func"};

    &$funcRef;
    printf "%12s: %s\n", $func, $_;
}


sub orig {
    $_ = $str;
    s/(.)(?=\1\1\1)//gs;
}


sub ccn {
    $_ = $str;
    s/(.)\1{3,}/$1$1$1/gs;
}


sub kvale {
    $_ = $str;
    s/(.)\1{2,}/$1$1$1/g;
}


sub JavaFan {
    $_ = $str;
    s/(.)\1{2,}/$1$1$1/g;
}


sub GF {
    $_ = $str;
    s/((.)\2\2)\2+/$1/g;
}


sub ikegami1 {
    $_ = $str;
    s/$ikegamiRe1/substr($_,$-[0],3)/eg;
}


sub ikegami2 {
    $_ = $str;
    s/$ikegamiRe1//g;
}


sub ikegami2A {
    $_ = $str;
    s/$ikegamiReA//g;
}


sub ikegami2x {
    my ($re) = map qr/$_/, join '|', map "(?<=${_}{3})$_+", map quotemeta, 1 .. 9;

    $_ = $str;
    s/$re//g;
}


sub ikegami3 {
    $_ = $str;
    s/($ikegamiRe1)/substr($1,0,3)/eg;
}

sub mrm_long {
    my $len = length $_[1];

    ### loop prelude
    my $char = substr $_[1], 0, 1;
    my $count = 1;
    my $new_string = $char;
    my $at = 1;

    while ( $at < $len ) {
        my $old_char = $char;
        $char = substr $_[1], $at++, 1;

        if ( $char eq $old_char ) {
            next if $count >= $_[0];
            $count++;
        } else {
            $count = 1;
        }
        $new_string .= $char;
    }

    return $new_string;
}

sub mrm_short {
    ( my  $new_string = $_[1] ) =~ s/(.)\1{$_[0],}/$1 x $_[0]/eg;
    return $new_string;
}

sub mrm_s_const {
    ( my  $new_string = $str ) =~ s/(.)\1{3,}/$1 x 3/eg;
    return $new_string;
}

sub mrm_l_const {
    my $len = length $str;

    ### loop prelude
    my $char = substr $str, 0, 1;
    my $count = 1;
    my $new_string = $char;
    my $at = 1;

    while ( $at < $len ) {
        my $old_char = $char;
        $char = substr $str, $at++, 1;

        if ( $char eq $old_char ) {
            next if $count >= 3;
            $count++;
        } else {
            $count = 1;
        }
        $new_string .= $char;
    }

    return $new_string;
}