Opcode Descriptions and Examples
PHP Manual

IS_SMALLER_OR_EQUAL

PHP code

<?php
/*
 * compares if value1 is less than or equal to value2
 * opcode number: 20
 */
echo (<= 1);
?>

PHP opcodes

Function name: (null)

Compiled variables: none

line#op fetchextreturn operands
60 IS_SMALLER_OR_EQUAL   ~0 2,1
 1 ECHO     ~0
72 RETURN     1

Opcode Descriptions and Examples
PHP Manual