X86-assembly/Instructions/xor
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Description
- The xor instruction performs a logical XOR (exclusive OR) operation.
- This is the equivalent to the "^" operator in python:
>>> hex(0x18 ^ 0x7575) '0x756d'
Syntax
xor destination, value
Affected flags
- The OF and CF flags are cleared
- The SF, ZF, and PF flags are set according to the result
- The state of the AF flag is undefined.
Examples
mov eax, 0x18 ;11000 in binary xor eax, 0x7575 ;111010101110101 in binary The above example will store 0x756D (111010101101101 in binary) into EAX. |
00000000 00011000 01110101 01110101 ----------------- 01110101 01101101 |
For optimization purposes (it only requires 2 bytes), the xor instruction is often used that way to clear the value of a register:
xor eax, eax ; clears the EAX register