Opcode Descriptions and Examples
PHP Manual

ASSIGN_BW_XOR

PHP code

<?php
/*
 * Performs binary XOR on result and value1and stores in variable indicated by result.
 * opcode number: 33
 */
$a ^= 64;
?>

PHP opcodes

Function name: (null)

Compiled variables: !0=$a

line#op fetchextreturn operands
60 ASSIGN_BW_XOR     !0,64
71 RETURN     1

Opcode Descriptions and Examples
PHP Manual