Opcode Descriptions and Examples
PHP 手册

POST_DEC

PHP code

<?php
/*
 * decrements variable indicated by value1 by 1 (after performing other operations) and stores in result
 * opcode number: 37
 */
$a--;
?>

PHP opcodes

Function name: (null)

Compiled variables: !0=$a

line#op fetchextreturn operands
60 POST_DEC   ~0 !0
 1 FREE     ~0
72 RETURN     1

Opcode Descriptions and Examples
PHP 手册