package MyXMLSimple;
use base 'XML::Simple';

sub sorted_keys { my ( $self, $name, $hashref ) = @_; return sort { main::element_order($a) <=> main::element_order($b) } keys(%{$hashref}); };

... SNIP ...

return $parser->XMLout($xml,
        KeyAttr       => [],
        RootName      => 'Zymonic',
        NoEscape      => 1,
        SuppressEmpty => 1
);

##</code><code>##

sub add_nodes_hash
{
	#first time $xml will be the file, after that it will be the hash or array ref
	# $is_child is a flag to see if it wants to be added as like a root node, or part of a nest
	my $xml = shift;
	my $parent_element = shift;
	
	foreach my $node (sort {element_order($a) <=> element_order($b)} keys %{$xml})
	{
		#next if ($node =~/\//);		
		if (ref($xml->{$node}) eq 'HASH')
		{
			my $element = $dom->createElement( $node );
			$parent_element->insertAfter($element,undef);
			add_nodes_hash($xml->{$node},$element);
		}
		if (ref( $xml->{$node} ) eq 'ARRAY')
		{
			
			foreach my $array_element (@{$xml->{$node}})
			{
				if (ref($array_element) eq 'HASH')
				{
					my $element = $dom->createElement( $node );
					my @attributes = $element->attributes();
					$parent_element->insertAfter($element,undef);
					add_nodes_hash($array_element,$element);
				}
				elsif (!ref( $xml->{$node} ) && ($xml->{$node}))
				{
					my $element = $dom->createElement( $node );
					$element->appendText($xml->{$node});
					$parent_element->insertAfter($element,undef);
				}
			}
		}
		elsif (!ref( $xml->{$node} ) && ($xml->{$node}))
		{
			my $element = $dom->createElement( $node );
			$element->appendText($xml->{$node});
			$parent_element->insertAfter($element,undef);
		}	
	}
	return $dom;
}

sub libxml_output {
my $xml = shift;
#create the dom object
$dom = XML::LibXML::Document->new();


my $root = $dom->createElement('Zymonic');
$dom->setDocumentElement($root);
add_nodes_hash($xml, $root);
return $dom->toString(1);

}

##</code><code>##

====================TIMINGS=======================
LibXML time for 100 rep(s): 5409.750 ms
XML Simple time for 100 rep(s): 3699.437 ms