You have 60,000 queries, and they even search along the descendant axis (which tends to include lots of nodes). Why don't you extract all the "w" nodes out first, then search through those. 

use strict;
use warnings;
use XML::LibXML;

my $file = $ARGV[0];

my $parser = XML::LibXML->new();
my $doc    = $parser->parse_file($file);
my $root   = $doc->documentElement();

for my $w_node (
    $root->findnodes('/e/p//w')
) {
    my ($wn_anchor) = $w_node->findnodes('a[@name="wn"]') or next;
    my ($l_anchor)  = $w_node->findnodes('a[@name="l"]' ) or next;

    ...
}

[download]

Your original sorted the results by id. I didn't replicate that behaviour.
Your original ignored ids over 32812. I didn't replicate that behaviour.
Were you expecting more than one anchor with each name? I ignore all but the first.
Let me know if you want any of the above changed.

In reply to Re: large XML file in using XPATH by ikegami
in thread large XML file in using XPATH by Anonymous Monk

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