1:29 >perl 868_SoPW.pl

no integer
unmasked: 0x1ffffffff = 8589934591
masked:   0x1 = 1

use integer
unmasked: 0xffffffffffffffff = -1
masked:   0x1 = 1

 1:29 >perl -v

This is perl 5, version 18, subversion 2 (v5.18.2) built for MSWin32-x86-multi-thread-64int