The bitwise exclusive OR takes two bit patterns of equal length and performs the logical XOR operation on each pair of corresponding bits. The result in each position is 1 if the two bits are different, and 0 if they are the same. If either input argument is NULL, the function returns NULL.

If the target_arg and bit_mask_arg arguments differ in length, the arguments are processed as follows:

- The target_arg and bit_mask_arg arguments are aligned on their least significant byte/bit.
- The smaller argument is padded with zeros to the left until it becomes the same size as the larger argument.