LOGICAL OPERATORS

Operator	Description	Result
and	Logical AND	1 if both bits are 1, otherwise 0
or	Logical OR	1 if either bit is 1, otherwise 0
not	Logical NOT	Inverts the bits of the operand
xor	Logical XOR	1 if the bits are different, otherwise 0

---

AND Operation

The and instruction is used to perform logical AND operations. If both bits are 1, the result is 1; otherwise, it’s 0.

section .data

section .text
    global _start

_start:
    mov eax, 0b1010  ; Load binary value 1010 into eax
    mov ebx, 0b1100  ; Load binary value 1100 into ebx
    and eax, ebx     ; Perform logical AND operation

eax = 0b1010 = 10
ebx = 0b1100 = 12
------------
eax = 0b1000 = 8

I used binary values because it’s easier to understand with logical operators. This instruction performs a bitwise AND operation between the values in eax and ebx, storing the result in eax. The result of this operation is 0b1000.

---

OR Operation

The or instruction is used to perform logical OR operations. If either bit is 1, the result is 1 otherwise, it’s 0.

section .data

section .text
    global _start

_start:
    mov eax, 0b1010  ; Load binary value 1010 into eax
    mov ebx, 0b1100  ; Load binary value 1100 into ebx
    or eax, ebx      ; Perform logical OR operation

eax = 0b1010 = 10
ebx = 0b1100 = 12
------------
eax = 0b1110 = 14

This instruction performs a bitwise OR operation between the values in eax and ebx, storing the result in eax. The result of this operation is 0b1110.

---

NOT Operation

The not instruction is used to perform logical NOT operations. It inverts the bits of the operand.

section .data

section .text
    global _start

_start:
    mov eax, 0b1010  ; Load binary value 1010 into eax
    not eax          ; Perform logical NOT operation

eax = 0b1010 = 10
------------
eax = 0b0101 = 5

This instruction performs a bitwise NOT operation on the value in eax, storing the result in eax. The result of this operation is 0b0101.

One important thing about the not instruction is that it inverts all the bits of the operand, which may not be what I expected.

eax = 0b1010 0000 0000 0000 0000 0000 0000 0000
-----------------------------------------------
eax = 0b0101 1111 1111 1111 1111 1111 1111 1111

To avoid this, I can mask the upper bits to focus on the lower bits.

section .data

section .text
    global _start

_start:
    mov eax, 0b1010
    not eax
    AND eax, 0x0000000F ; Mask the upper 28 bits
                        ; can also use 0xF

In this case, I used the and instruction to mask the upper 28 bits of the result. This way, I can ignore the upper bits and focus on the lower 4 bits, which is the result of the not operation.

---

XOR Operation

The xor instruction is used to perform logical XOR operations. If the bits are different, the result is 1 otherwise, it’s 0.

section .data

section .text
    global _start

_start:
    mov eax, 0b1010  ; Load binary value 1010 into eax
    mov ebx, 0b1100  ; Load binary value 1100 into ebx
    xor eax, ebx     ; Perform logical XOR operation

eax = 0b1010 = 10
ebx = 0b1100 = 12
------------
eax = 0b0110 = 6

This instruction performs a bitwise XOR operation between the values in eax and ebx, storing the result in eax. The result of this operation is 0b0110.