my %want_global = map { ($_ => 1) } qw(
  THIS
  THAT
  ANOTHER
);

...
if ( $want_global{$global} ) {
 ...
}

##</code><code>##

my @wanted_re = (
  qr/^AB/,
  qr/^CD/,
);
sub want_global {
  my $g = shift;
  for my $re (@wanted_re) {
    return 1 if $g =~ /$re/;
  }
  return;
}