Opcode Support

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The embedded runtime implements the opcode subset documented below. Opcodes not handled by the runtime are rejected with an Unsupported opcode execution error.

Constants

Opcode	Hex	Gas	Description
PUSHINT8	0x00	1	Push 1-byte signed integer
PUSHINT16	0x01	1	Push 2-byte signed integer
PUSHINT32	0x02	1	Push 4-byte signed integer
PUSHINT64	0x03	1	Push 8-byte signed integer
PUSHINT128	0x04	1	Push 16-byte signed integer
PUSHINT256	0x05	1	Push 32-byte signed integer
PUSHT	0x08	1	Push true
PUSHF	0x09	1	Push false
PUSHA	0x0A	1	Push address (pointer)
PUSHNULL	0x0B	1	Push null
PUSHDATA1	0x0C	2	Push data (1-byte length prefix)
PUSHDATA2	0x0D	2	Push data (2-byte length prefix)
PUSHDATA4	0x0E	2	Push data (4-byte length prefix)
PUSHM1	0x0F	1	Push -1
PUSH0-PUSH16	0x10-0x20	1	Push small integers 0 through 16

Flow Control

Opcode	Hex	Gas	Description
NOP	0x21	1	No operation
JMP / JMP_L	0x22 / 0x23	2	Unconditional jump (short/long offset)
JMPIF / JMPIF_L	0x24 / 0x25	2	Jump if top is true
JMPIFNOT / JMPIFNOT_L	0x26 / 0x27	2	Jump if top is false
JMPEQ / JMPEQ_L	0x28 / 0x29	2	Jump if top two are equal
JMPNE / JMPNE_L	0x2A / 0x2B	2	Jump if top two are not equal
JMPGT / JMPGT_L	0x2C / 0x2D	2	Jump if greater than
JMPGE / JMPGE_L	0x2E / 0x2F	2	Jump if greater or equal
JMPLT / JMPLT_L	0x30 / 0x31	2	Jump if less than
JMPLE / JMPLE_L	0x32 / 0x33	2	Jump if less or equal
CALL / CALL_L	0x34 / 0x35	512	Call function (short/long offset)
CALLA	0x36	512	Call address on stack
CALLT	0x37	512	Call method token (native contract optimization)
ABORT	0x38	1	Abort execution unconditionally
ASSERT	0x39	1	Abort if top is false
THROW	0x3A	1	Throw exception
TRY / TRY_L	0x3B / 0x3C	1	Begin try block (catch/finally offsets)
ENDTRY / ENDTRY_L	0x3D / 0x3E	1	End try block
ENDFINALLY	0x3F	1	End finally block (rethrows pending exception)
RET	0x40	0	Return from current context
SYSCALL	0x41	10	Invoke system interop (4-byte hash follows)

Stack Operations

Opcode	Hex	Gas	Description
DEPTH	0x43	2	Push stack depth
DROP	0x45	2	Remove top item
NIP	0x46	2	Remove second item
XDROP	0x48	2	Remove item at index N
CLEAR	0x49	2	Clear the stack
DUP	0x4A	2	Duplicate top item
OVER	0x4B	2	Copy second item to top
PICK	0x4D	2	Copy item at index N to top
TUCK	0x4E	2	Insert top item below second
SWAP	0x50	2	Swap top two items
ROT	0x51	2	Rotate top three items
ROLL	0x52	2	Move item at index N to top
REVERSE3	0x53	2	Reverse top 3 items
REVERSE4	0x54	2	Reverse top 4 items
REVERSEN	0x55	2	Reverse top N items

Splice and Buffer

Opcode	Hex	Gas	Description
NEWBUFFER	0x88	4	Create new buffer of given size
MEMCPY	0x89	4	Copy bytes between buffers
CAT	0x8B	4	Concatenate two byte arrays
SUBSTR	0x8C	4	Extract substring
LEFT	0x8D	4	Take left N bytes
RIGHT	0x8E	4	Take right N bytes

Bitwise and Logic

Opcode	Hex	Gas	Description
INVERT	0x90	3	Bitwise NOT
AND	0x91	3	Bitwise AND
OR	0x92	3	Bitwise OR
XOR	0x93	3	Bitwise XOR
EQUAL	0x97	3	Equality comparison
NOTEQUAL	0x98	3	Inequality comparison

Numeric

Opcode	Hex	Gas	Description
SIGN	0x99	3	Push sign (-1, 0, 1)
ABS	0x9A	3	Absolute value
NEGATE	0x9B	3	Negate
INC / DEC	0x9C / 0x9D	3	Increment / decrement
ADD / SUB	0x9E / 0x9F	3	Addition / subtraction
MUL / DIV / MOD	0xA0 / 0xA1 / 0xA2	5	Multiplication / division / modulo
POW	0xA3	8	Exponentiation
SQRT	0xA4	6	Integer square root
MODMUL / MODPOW	0xA5 / 0xA6	8	Modular multiply / modular power
SHL / SHR	0xA8 / 0xA9	3	Shift left / shift right
NOT	0xAA	2	Logical NOT
BOOLAND / BOOLOR	0xAB / 0xAC	2	Logical AND / OR
NZ	0xB1	2	Non-zero test
NUMEQUAL / NUMNOTEQUAL	0xB3 / 0xB4	3	Numeric equality
LT / LE / GT / GE	0xB5-0xB8	3	Comparison operators
MIN / MAX	0xB9 / 0xBA	3	Minimum / maximum
WITHIN	0xBB	3	Range check (a <= x < b)

Compound and Collections

Opcode	Hex	Gas	Description
PACKMAP	0xBE	4	Pack key-value pairs into map
PACKSTRUCT	0xBF	4	Pack items into struct
PACK / UNPACK	0xC0 / 0xC1	4	Pack/unpack array
NEWARRAY0 / NEWARRAY / NEWARRAY_T	0xC2 / 0xC3 / 0xC4	4	Create arrays
NEWSTRUCT0 / NEWSTRUCT	0xC5 / 0xC6	4	Create structs
NEWMAP	0xC8	4	Create empty map
SIZE	0xCA	4	Get collection/string size
HASKEY	0xCB	4	Check if key exists
KEYS / VALUES	0xCC / 0xCD	4	Get map keys / values
PICKITEM	0xCE	4	Get item by index/key
APPEND	0xCF	4	Append to array
SETITEM	0xD0	4	Set item by index/key
REVERSEITEMS	0xD1	4	Reverse collection in place
REMOVE	0xD2	4	Remove item by index/key
CLEARITEMS	0xD3	4	Clear all items
POPITEM	0xD4	4	Pop last item from array

Type Operations

Opcode	Hex	Gas	Description
ISNULL	0xD8	2	Check if top is null
ISTYPE	0xD9	2	Check if top matches type code
CONVERT	0xDB	2	Convert top to specified type

Supported type codes:

Code	Type
0x20	Boolean
0x21	Integer
0x28	ByteString
0x30	Buffer
0x40	Array
0x41	Struct
0x48	Map
0x60	InteropInterface

Extensions

Opcode	Hex	Gas	Description
ABORTMSG	0xE0	1	Abort with message
ASSERTMSG	0xE1	1	Assert with message