I must admit first I'm looking at PDL and at your work in the same way a, let say, an hystorician can look at a Stephen Hawking movie: very interesting but I do not understand nothing.. ;=)

That said, I've used a strawberry perl perl-5.26.64bit-PDL version (portable 5.26 failed installing PDL at Inline::C step ) and I got (just once before time zero generation):

Possible precedence problem on bitwise & operator at pdl-gameoflife.pl
+ line 24, <DATA> line 207.
Possible precedence problem on bitwise | operator at pdl-gameoflife.pl
+ line 25, <DATA> line 207.
[download]

I poked it a bit ( reading PDL::FAQ too: good think to link to FAQ from errors!)

and the following version, with parens superfetation, gives no warnings:

return ( ($tmp == 4) & ($pdl == 1) ) |    # Alive +3 neighbors
     ( $tmp == 3);    #  Alive +2 neighbors or dead +3 neighbors
[download]

Just my 2 neurocents.. I'll stay tuned looking for your precious nodes!

L*