# Zend Engine 2 Opcodes

## Table of Contents

- Opcode Descriptions and Examples

When parsing PHP files, Zend Engine 2 generates a series of operation codes, commonly known as "opcodes", representing the function of the code. This part of the manual details those opcodes and their behaviour.

Opcodes may be dumped for a given PHP file using the vld extension (see » https://pecl.php.net/package/vld).

Opcode List
Number | Name | Has sample code?
--- | --- | ---
0 | NOP | yes
1 | ADD | yes
2 | SUB | yes
3 | MUL | yes
4 | DIV | yes
5 | MOD | yes
6 | SL | yes
7 | SR | yes
8 | CONCAT | yes
9 | BW_OR | yes
10 | BW_AND | yes
11 | BW_XOR | yes
12 | BW_NOT | yes
13 | BOOL_NOT | yes
14 | BOOL_XOR | yes
15 | IS_IDENTICAL | yes
16 | IS_NOT_IDENTICAL | yes
17 | IS_EQUAL | yes
18 | IS_NOT_EQUAL | yes
19 | IS_SMALLER | yes
20 | IS_SMALLER_OR_EQUAL | yes
21 | CAST | yes
22 | QM_ASSIGN | yes
23 | ASSIGN_ADD | yes
24 | ASSIGN_SUB | yes
25 | ASSIGN_MUL | yes
26 | ASSIGN_DIV | yes
27 | ASSIGN_MOD | yes
28 | ASSIGN_SL | yes
29 | ASSIGN_SR | yes
30 | ASSIGN_CONCAT | yes
31 | ASSIGN_BW_OR | yes
32 | ASSIGN_BW_AND | yes
33 | ASSIGN_BW_XOR | yes
34 | PRE_INC | yes
35 | PRE_DEC | yes
36 | POST_INC | yes
37 | POST_DEC | yes
38 | ASSIGN | yes
39 | ASSIGN_REF | yes
40 | ECHO | yes
41 | PRINT | yes
42 | JMP | yes
43 | JMPZ | yes
44 | JMPNZ | yes
45 | JMPZNZ | yes
46 | JMPZ_EX | yes
47 | JMPNZ_EX | yes
48 | CASE | yes
49 | SWITCH_FREE | yes
50 | BRK | yes
51 | CONT | yes
52 | BOOL | yes
53 | INIT_STRING | yes
54 | ADD_CHAR | yes
55 | ADD_STRING | yes
56 | ADD_VAR | yes
57 | BEGIN_SILENCE | yes
58 | END_SILENCE | yes
59 | INIT_FCALL_BY_NAME | yes
60 | DO_FCALL | yes
61 | DO_FCALL_BY_NAME | yes
62 | RETURN | yes
63 | RECV | yes
64 | RECV_INIT | yes
65 | SEND_VAL | yes
66 | SEND_VAR | yes
67 | SEND_REF | yes
68 | NEW | yes
69 | INIT_NS_FCALL_BY_NAME | no
70 | FREE | yes
71 | INIT_ARRAY | yes
72 | ADD_ARRAY_ELEMENT | yes
73 | INCLUDE_OR_EVAL | yes
74 | UNSET_VAR | yes
75 | UNSET_DIM | yes
76 | UNSET_OBJ | yes
77 | FE_RESET | yes
78 | FE_FETCH | yes
79 | EXIT | yes
80 | FETCH_R | yes
81 | FETCH_DIM_R | yes
82 | FETCH_OBJ_R | yes
83 | FETCH_W | yes
84 | FETCH_DIM_W | yes
85 | FETCH_OBJ_W | yes
86 | FETCH_RW | yes
87 | FETCH_DIM_RW | yes
88 | FETCH_OBJ_RW | yes
89 | FETCH_IS | yes
90 | FETCH_DIM_IS | no
91 | FETCH_OBJ_IS | no
92 | FETCH_FUNC_ARG | yes
93 | FETCH_DIM_FUNC_ARG | yes
94 | FETCH_OBJ_FUNC_ARG | yes
95 | FETCH_UNSET | no
96 | FETCH_DIM_UNSET | no
97 | FETCH_OBJ_UNSET | no
98 | FETCH_DIM_TMP_VAR | yes
99 | FETCH_CONSTANT | yes
100 | GOTO | no
101 | EXT_STMT | yes
102 | EXT_FCALL_BEGIN | no
103 | EXT_FCALL_END | no
104 | EXT_NOP | no
105 | TICKS | yes
106 | SEND_VAR_NO_REF | no
107 | CATCH | yes
108 | THROW | yes
109 | FETCH_CLASS | yes
110 | CLONE | yes
111 | RETURN_BY_REF | no
112 | INIT_METHOD_CALL | yes
113 | INIT_STATIC_METHOD_CALL | yes
114 | ISSET_ISEMPTY_VAR | yes
115 | ISSET_ISEMPTY_DIM_OBJ | yes
116 | ZEND_SEND_VAL_EX | no
117 | ZEND_SEND_VAR | no
118 | ZEND_INIT_USER_CALL | no
119 | ZEND_SEND_ARRAY | no
120 | ZEND_SEND_USER | no
121 | ZEND_STRLEN | no
122 | ZEND_DEFINED | no
123 | ZEND_TYPE_CHECK | no
124 | ZEND_VERIFY_RETURN_TYPE | no
125 | ZEND_FE_RESET_RW | no
126 | ZEND_FE_FETCH_RW | no
127 | ZEND_FE_FREE | no
128 | ZEND_INIT_DYNAMIC_CALL | no
129 | ZEND_DO_ICALL | no
130 | ZEND_DO_UCALL | no
131 | ZEND_DO_FCALL_BY_NAME | no
132 | PRE_INC_OBJ | yes
133 | PRE_DEC_OBJ | yes
134 | POST_INC_OBJ | yes
135 | POST_DEC_OBJ | yes
136 | ASSIGN_OBJ | yes
137 | ZEND_OP_DATA | no
138 | INSTANCEOF | yes
139 | DECLARE_CLASS | yes
140 | DECLARE_INHERITED_CLASS | yes
141 | DECLARE_FUNCTION | yes
142 | RAISE_ABSTRACT_ERROR | yes
143 | DECLARE_CONST | no
144 | ADD_INTERFACE | no
145 | DECLARE_INHERITED_CLASS_DELAYED | no
146 | VERIFY_ABSTRACT_CLASS | no
147 | ASSIGN_DIM | yes
148 | ISSET_ISEMPTY_PROP_OBJ | yes
149 | HANDLE_EXCEPTION | yes
150 | USER_OPCODE | no
151 | ZEND_ASSERT_CHECK | no
152 | ZEND_JMP_SET | no
153 | ZEND_DECLARE_LAMBDA_FUNCTION | no
154 | ZEND_ADD_TRAIT | no
155 | ZEND_BIND_TRAITS | no
156 | ZEND_SEPARATE | no
157 | ZEND_FETCH_CLASS_NAME | no
158 | ZEND_CALL_TRAMPOLINE | no
159 | ZEND_DISCARD_EXCEPTION | no
160 | ZEND_YIELD | no
161 | ZEND_GENERATOR_RETURN | no
162 | ZEND_FAST_CALL | no
163 | ZEND_FAST_RET | no
164 | ZEND_RECV_VARIADIC | no
165 | ZEND_SEND_UNPACK | no
166 | ZEND_POW | no
167 | ZEND_ASSIGN_POW | no
168 | ZEND_BIND_GLOBAL | no
169 | ZEND_COALESCE | no
170 | ZEND_SPACESHIP | no
171 | ZEND_DECLARE_ANON_CLASS | no
172 | ZEND_DECLARE_ANON_INHERITED_CLASS | no
173 | ZEND_FETCH_STATIC_PROP_R | no
174 | ZEND_FETCH_STATIC_PROP_W | no
175 | ZEND_FETCH_STATIC_PROP_RW | no
176 | ZEND_FETCH_STATIC_PROP_IS | no
177 | ZEND_FETCH_STATIC_PROP_FUNC_ARG | no
178 | ZEND_FETCH_STATIC_PROP_UNSET | no
179 | ZEND_UNSET_STATIC_PROP | no
180 | ZEND_ISSET_ISEMPTY_STATIC_PROP | no
181 | ZEND_FETCH_CLASS_CONSTANT | no
182 | ZEND_BIND_LEXICAL | no
183 | ZEND_BIND_STATIC | no
184 | ZEND_FETCH_THIS | no
185 | ZEND_SEND_FUNC_ARG | no
186 | ZEND_ISSET_ISEMPTY_THIS | no
187 | ZEND_SWITCH_LONG | no
188 | ZEND_SWITCH_STRING | no
189 | ZEND_IN_ARRAY | no
190 | ZEND_COUNT | no
191 | ZEND_GET_CLASS | no
192 | ZEND_GET_CALLED_CLASS | no
193 | ZEND_GET_TYPE | no
194 | ZEND_FUNC_NUM_ARGS | no
195 | ZEND_FUNC_GET_ARGS | no
196 | ZEND_UNSET_CV | no
197 | ZEND_ISSET_ISEMPTY_CV | no

Pseudo-opcodes that are used only temporarily during compilation.

Pseudo-opcodes List
Number | Name | Has sample code?
--- | --- | ---
253 | ZEND_GOTO | no
254 | ZEND_BRK | no
255 | ZEND_CONT | no