I believe labels have such poor performance because they're resolved at runtime!

my $label;

LABEL:
warn "label = $label\n";
$label = $label ? 'LAST': 'LABEL';
goto $label;

LAST:
warn "done, label = $label\n";

__END__
label = 
label = LABEL
done, label = LAST
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Of course, that means you can easily go to a different label determined by run-time conditions (as shown above). To quote Johan Cruyff "Every advantage has its disadvantage". ;-)

Liz