NOT

Table of Contents

1. NOT (not)
   1. Basic function
   2. Instruction execution process
   3. Instruction format
   4. Behavioral characteristics
   5. Common uses

NOT (not)

Basic function

NOT performs a bitwise inversion on the operand: dest = ~dest.
That is, all bits 0 → 1, and 1 → 0.

Instruction execution process

• Invert each bit
• Write the result back to the destination operand
• Does not affect any EFLAGS

Instruction format

1
not r/m8
2
not r/m16
3
not r/m32
4
not r/m64

Behavioral characteristics

• Single-operand instruction
• Does not modify flags
• Can be used to construct values, encryption, and mask processing

Common uses

• Constructing special immediates (with XOR, ADD, etc.)
• Implementing two’s complement relationships in logical operations
• Reversing all bits for verification and algorithm analysis
• Avoiding the direct appearance of certain bytes in shellcode