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 » http://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	not documented	no
117	not documented	no
118	not documented	no
119	not documented	no
120	not documented	no
121	not documented	no
122	not documented	no
123	not documented	no
124	not documented	no
125	not documented	no
126	not documented	no
127	not documented	no
128	not documented	no
129	not documented	no
130	not documented	no
131	not documented	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	not documented	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
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