NOT
Usage: NOT dest Modifies flags: None
Inverts the bits of the 'dest' operand forming the one's complement.
Two's and One's Complement
NEG r/m8 ; F6 /3 [8086]
NEG r/m16 ; o16 F7 /3 [8086]
NEG r/m32 ; o32 F7 /3 [386]
NOT r/m8 ; F6 /2 [8086]
NOT r/m16 ; o16 F7 /2 [8086]
NOT r/m32 ; o32 F7 /2 [386]
NEG replaces the contents of its operand by the two's complement negation (invert all the bits and then adds one to the result) of the original value.
NOT , similarly, performs one's complement (inverts all the bits, but does not add one to the result).
Example:
mov eax 5
not eax ; eax= FFFF FFFA > -6