use bignum: 
use bignum;

my $var1 = 0x0000805063008357 ;
my $var2 = 0x042426FFFFFFFFFF ;

my $result =  $var1 ^ $var2;
printf "0x%016x\n",$result;

[download]
Gives:
0x00000000ffffffff

[download]
Which goes to show that printf does not support big ints.
Update: improved printf

In reply to Re^3: Hexadecimal Exclusive OR by cdarke
in thread Hexadecimal Exclusive OR by Anonymous Monk

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