^ xor with a bitmask where the 1’s will be flipped
eg
a = 1010101
b = 1111111
a^b = 0101010
a = 1101101
b = 0010011
a^b = 1111110
^ xor with a bitmask where the 1’s will be flipped
a = 1010101
b = 1111111
a^b = 0101010
a = 1101101
b = 0010011
a^b = 1111110