Could you put it into a Tie::Array::Pack or Tie::Array::Packed array and just use sort?

That does not work as you expect, sort unpacks the array before sorting it.

Though, Tie::Array::Packed has a sort method that can be used for that. For instance:

tie my @p, 'Tie::Array::Packed::Integer';
push @p, $_ for (.....);

tied(@p)->sort;
[download]

(it just calls Sort::Packed under the hood)