dest = ~dest
The not instruction nots the destination The destination can be a 64, 32, 16 or 8 bit register or memory location.
The operation performs a bitwise not of the 2 operands. Not flips all the bits of its operand. Here is an example of a bitwise not.
~1010010010101011
----------------
0101101101010100
Some examples of using not:
not rax ; not rax
not eax ; not eax
; fills upper half of rax with 0
not dx ; not dx
; leaves the rest of rdx alone
not dword [x] ; not 32 bit varaible x