3 ms·

No because it takes two inputs and gives two outputs. One input is passed through unchanged, and the other output is indeed xor.

• saagarjha 6y ago
  And hence it is reversible, since you can get the inputs back from that output!
  • sukilot 6y ago
    In normal human arithmetic, it's equivalent to saying something like "7+5= 12" and remembering the "+5" so you can undo it later.