Opcode and Host I/O Pricing

This reference provides the latest measurements of WASM opcodes and Host I/Os when using Stylus, in both ink and gas.

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Stylus is currently tagged as an alpha release. The code has not been audited, and should not be used in production scenarios. This documentation is currently in public preview.

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Opcode table

The Stylus VM charges for WASM opcodes according to the following table, which was determined via a conservative statistical analysis and is expected to change as Stylus matures. Prices may fluctuate across upgrades as our analysis evolves and optimizations are made.

Hex	Opcode	Ink	Gas	Notes
0x00	Unreachable	1	0.0001
0x01	Nop	1	0.0001
0x02	Block	1	0.0001
0x03	Loop	1	0.0001
0x04	If	2400	0.24
0x05	Else	1	0.0001
0x0b	End	1	0.0001
0x0c	Br	2400	0.24
0x0d	BrIf	2400	0.24
0x0e	BrTable	2400 + 325x	0.24 + 0.0325x	Cost varies with table size
0x0f	Return	1	0.0001
0x10	Call	13750	1.375
0x11	CallIndirect	13610 + 650x	1.361 + 0.065x	Cost varies with no. of args
0x1a	Drop	1	0.0001
0x1b	Select	4000	0.4	Large optimization opportunity
0x20	LocalGet	200	0.02
0x21	LocalSet	375	0.0375
0x22	LocalTee	200	0.02
0x23	GlobalGet	300	0.03
0x24	GlobalSet	990	0.099
0x28	I32Load	2200	0.22
0x29	I64Load	2750	0.275
0x2c	I32Load8S	2200	0.22
0x2d	I32Load8U	2200	0.22
0x2e	I32Load16S	2200	0.22
0x2f	I32Load16U	2200	0.22
0x30	I64Load8S	2750	0.275
0x31	I64Load8U	2750	0.275
0x32	I64Load16S	2750	0.275
0x33	I64Load16U	2750	0.275
0x34	I64Load32S	2750	0.275
0x35	I64Load32U	2750	0.275
0x36	I32Store	2400	0.24
0x37	I64Store	3100	0.31
0x3a	I32Store8	2400	0.24
0x3b	I32Store16	2400	0.24
0x3c	I64Store8	3100	0.31
0x3d	I64Store16	3100	0.31
0x3e	I64Store32	3100	0.31
0x3f	MemorySize	13500	1.35
0x40	MemoryGrow	1	0.0001
0x41	I32Const	1	0.0001
0x42	I64Const	1	0.0001
0x45	I32Eqz	570	0.057
0x46	I32Eq	570	0.057
0x47	I32Ne	570	0.057
0x48	I32LtS	570	0.057
0x49	I32LtU	570	0.057
0x4a	I32GtS	570	0.057
0x4b	I32GtU	570	0.057
0x4c	I32LeS	570	0.057
0x4d	I32LeU	570	0.057
0x4e	I32GeS	570	0.057
0x4f	I32GeU	570	0.057
0x50	I64Eqz	760	0.076
0x51	I64Eq	760	0.076
0x52	I64Ne	760	0.076
0x53	I64LtS	760	0.076
0x54	I64LtU	760	0.076
0x55	I64GtS	760	0.076
0x56	I64GtU	760	0.076
0x57	I64LeS	760	0.076
0x58	I64LeU	760	0.076
0x59	I64GeS	760	0.076
0x5a	I64GeU	760	0.076
0x67	I32Clz	750	0.075
0x68	I32Ctz	750	0.075
0x69	I32Popcnt	500	0.05
0x6a	I32Add	200	0.02
0x6b	I32Sub	200	0.02
0x6c	I32Mul	550	0.055
0x6d	I32DivS	2500	0.25
0x6e	I32DivU	2500	0.25
0x6f	I32RemS	2500	0.25
0x70	I32RemU	2500	0.25
0x71	I32And	200	0.02
0x72	I32Or	200	0.02
0x73	I32Xor	200	0.02
0x74	I32Shl	200	0.02
0x75	I32ShrS	200	0.02
0x76	I32ShrU	200	0.02
0x77	I32Rotl	200	0.02
0x78	I32Rotr	200	0.02
0x79	I64Clz	750	0.075
0x7a	I64Ctz	750	0.075
0x7b	I64Popcnt	750	0.075
0x7c	I64Add	200	0.02
0x7d	I64Sub	200	0.02
0x7e	I64Mul	550	0.055
0x7f	I64DivS	2900	0.29
0x80	I64DivU	2900	0.29
0x81	I64RemS	2900	0.29
0x82	I64RemU	2900	0.29
0x83	I64And	200	0.02
0x84	I64Or	200	0.02
0x85	I64Xor	200	0.02
0x86	I64Shl	200	0.02
0x87	I64ShrS	200	0.02
0x88	I64ShrU	200	0.02
0x89	I64Rotl	200	0.02
0x8a	I64Rotr	200	0.02
0xa7	I32WrapI64	200	0.02
0xac	I64ExtendI32S	200	0.02
0xad	I64ExtendI32U	200	0.02
0xc0	I32Extend8S	200	0.02
0xc1	I32Extend16S	200	0.02
0xc2	I64Extend8S	200	0.02
0xc3	I64Extend16S	200	0.02
0xc4	I64Extend32S	200	0.02
0xfc0a	MemoryCopy	3100 + 125x	0.31 + 0.0125x	Cost varies with no. of bytes
0xfc0b	MemoryFill	3100 + 125x	0.31 + 0.0125x	Cost varies with no. of bytes

VM affordances

Certain operations require suspending WASM execution so that the Stylus VM can perform tasks natively in the host. This costs about 1.25 gas to do. Though we’ll publish a full specification later, the following table details the costs of simple operations that run in the host.

Note that the values in this table were determined via a conservative statistical analysis and are expected to change as Stylus matures. Prices may fluctuate across upgrades as our analysis evolves and optimizations are made.

Host I/O	Ink	Gas	Notes
read_args	12513 + 18287b	1.2513 + 1.8287b	b = bytes after first 32
write_result	12513 + 40423b	12513 + 4.0423b	b = bytes after first 32
keccak	281040 + 41920w	28.104 + 4.192w	Due to a pricing mistake, keccak will soon be ~8 gas cheaper! w = EVM words
block_basefee	22137	2.2137
block_coinbase	22137	2.2137
block_gas_limit	12513	1.2513
block_number	12513	1.2513
block_timestmap	12513	1.2513
chain_id	12513	1.2513
contract_address	22137	2.2137
evm_gas_left	12513	1.2513
evm_ink_left	12513	1.2513
msg_reentrant	12513	1.2513
msg_sender	22137	2.2137
msg_value	22137	2.2137
return_data_size	12513	1.2513
tx_ink_price	12513	1.2513
tx_gas_price	22137	2.2137
tx_origin	22137	2.2137
console_log_text	0	0	debug-only
console_log	0	0	debug-only
console_tee	0	0	debug-only
null_host	0	0	debug-only

For some opcodes, the value in the table may be larger than its EVM equivalent. In the vast majority of real-world cases, the Stylus VM will still perform better. For example, getting the raw msg::value costs 0.2137 more gas in Stylus than it does in the EVM. But the moment one takes that value and does anything with it, Stylus becomes much cheaper. Recall that a single EVM ADD instruction costs 3 gas, during which 150 WASM ADD instructions may run.