$ cat 791149.pl
use strict;
use warnings;

use Net::IP::Match::Regexp qw( create_iprange_regexp match_ip );
use Benchmark qw / cmpthese /;

my $regexp_init_once =
  create_iprange_regexp( qw( 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 ) );

sub netip {
  my $regexp =
    create_iprange_regexp( qw( 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 ) );
  return ( match_ip( $_[0], $regexp ) );
}

sub netip_init_once {
  return match_ip( $_[0], $regexp_init_once );
}

sub regexp {
  return $_[0] =~ /^(10\.\d+|172\.(1[6-9]|2\d|3[0-1])|192\.168)(\.\d+){2}$/;
}

cmpthese(
  -1,
  {
    'netip'           => sub { netip('1.2.3.4') },
    'netip_init_once' => sub { netip_init_once('1.2.3.4') },
    'regexp'          => sub { regexp('1.2.3.4') },
  }
);

__END__
$ perl 791149.pl
                     Rate           netip netip_init_once          regexp
netip              2438/s              --            -96%           -100%
netip_init_once   67622/s           2674%              --            -95%
regexp          1390157/s          56918%           1956%              --