`test_worst_initcode_jumpdest_analysis()`¶

Documentation for tests/benchmark/test_worst_bytecode.py::test_worst_initcode_jumpdest_analysis@0f7c73a7.

Generate fixtures for these test cases for Prague with:

fill -v tests/benchmark/test_worst_bytecode.py::test_worst_initcode_jumpdest_analysis --fork Prague

Test the jumpdest analysis performance of the initcode.

This benchmark places a very long initcode in the memory and then invoke CREATE instructions with this initcode up to the block gas limit. The initcode itself has minimal execution time but forces the EVM to perform the full jumpdest analysis on the parametrized byte pattern. The initicode is modified by mixing-in the returned create address between CREATE invocations to prevent caching.

Source code in tests/benchmark/test_worst_bytecode.py

@pytest.mark.valid_from("Cancun")
@pytest.mark.parametrize(
    "pattern",
    [
        Op.STOP,
        Op.JUMPDEST,
        Op.PUSH1[bytes(Op.JUMPDEST)],
        Op.PUSH2[bytes(Op.JUMPDEST + Op.JUMPDEST)],
        Op.PUSH1[bytes(Op.JUMPDEST)] + Op.JUMPDEST,
        Op.PUSH2[bytes(Op.JUMPDEST + Op.JUMPDEST)] + Op.JUMPDEST,
    ],
    ids=lambda x: x.hex(),
)
def test_worst_initcode_jumpdest_analysis(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
    pattern: Bytecode,
):
    """
    Test the jumpdest analysis performance of the initcode.

    This benchmark places a very long initcode in the memory and then invoke CREATE instructions
    with this initcode up to the block gas limit. The initcode itself has minimal execution time
    but forces the EVM to perform the full jumpdest analysis on the parametrized byte pattern.
    The initicode is modified by mixing-in the returned create address between CREATE invocations
    to prevent caching.
    """
    max_code_size = fork.max_code_size()
    initcode_size = fork.max_initcode_size()

    # Expand the initcode pattern to the transaction data so it can be used in CALLDATACOPY
    # in the main contract. TODO: tune the tx_data_len param.
    tx_data_len = 1024
    tx_data = pattern * (tx_data_len // len(pattern))
    tx_data += (tx_data_len - len(tx_data)) * bytes(Op.JUMPDEST)
    assert len(tx_data) == tx_data_len
    assert initcode_size % len(tx_data) == 0

    # Prepare the initcode in memory.
    code_prepare_initcode = sum(
        (
            Op.CALLDATACOPY(dest_offset=i * len(tx_data), offset=0, size=Op.CALLDATASIZE)
            for i in range(initcode_size // len(tx_data))
        ),
        Bytecode(),
    )

    # At the start of the initcode execution, jump to the last opcode.
    # This forces EVM to do the full jumpdest analysis.
    initcode_prefix = Op.JUMP(initcode_size - 1)
    code_prepare_initcode += Op.MSTORE(
        0, Op.PUSH32[bytes(initcode_prefix).ljust(32, bytes(Op.JUMPDEST))]
    )

    # Make sure the last opcode in the initcode is JUMPDEST.
    code_prepare_initcode += Op.MSTORE(initcode_size - 32, Op.PUSH32[bytes(Op.JUMPDEST) * 32])

    code_invoke_create = (
        Op.PUSH1[len(initcode_prefix)]
        + Op.MSTORE
        + Op.CREATE(value=Op.PUSH0, offset=Op.PUSH0, size=Op.MSIZE)
    )

    initial_random = Op.PUSH0
    code_prefix = code_prepare_initcode + initial_random
    code_loop_header = Op.JUMPDEST
    code_loop_footer = Op.JUMP(len(code_prefix))
    code_loop_body_len = (
        max_code_size - len(code_prefix) - len(code_loop_header) - len(code_loop_footer)
    )

    code_loop_body = (code_loop_body_len // len(code_invoke_create)) * bytes(code_invoke_create)
    code = code_prefix + code_loop_header + code_loop_body + code_loop_footer
    assert (max_code_size - len(code_invoke_create)) < len(code) <= max_code_size

    env = Environment()

    tx = Transaction(
        to=pre.deploy_contract(code=code),
        data=tx_data,
        gas_limit=env.gas_limit,
        sender=pre.fund_eoa(),
    )

    state_test(
        env=env,
        pre=pre,
        post={},
        tx=tx,
    )

Parametrized Test Cases¶

The interactive table below is also available as a standalone page.

Test ID (Abbreviated)	pattern
...fork_Cancun-state_test-00	STOP
...fork_Cancun-state_test-5b	JUMPDEST
...fork_Cancun-state_test-605b	PUSH1_0x5b
...fork_Cancun-state_test-615b5b	PUSH2_0x5b5b
...fork_Cancun-state_test-605b5b
...fork_Cancun-state_test-615b5b5b
...fork_Cancun-blockchain_test_from_state_test-00	STOP
...fork_Cancun-blockchain_test_from_state_test-5b	JUMPDEST
...fork_Cancun-blockchain_test_from_state_test-605b	PUSH1_0x5b
...fork_Cancun-blockchain_test_from_state_test-615b5b	PUSH2_0x5b5b
...fork_Cancun-blockchain_test_from_state_test-605b5b
...fork_Cancun-blockchain_test_from_state_test-615b5b5b
...fork_Prague-state_test-00	STOP
...fork_Prague-state_test-5b	JUMPDEST
...fork_Prague-state_test-605b	PUSH1_0x5b
...fork_Prague-state_test-615b5b	PUSH2_0x5b5b
...fork_Prague-state_test-605b5b
...fork_Prague-state_test-615b5b5b
...fork_Prague-blockchain_test_from_state_test-00	STOP
...fork_Prague-blockchain_test_from_state_test-5b	JUMPDEST
...fork_Prague-blockchain_test_from_state_test-605b	PUSH1_0x5b
...fork_Prague-blockchain_test_from_state_test-615b5b	PUSH2_0x5b5b
...fork_Prague-blockchain_test_from_state_test-605b5b
...fork_Prague-blockchain_test_from_state_test-615b5b5b
...fork_Osaka-state_test-00	STOP
...fork_Osaka-state_test-5b	JUMPDEST
...fork_Osaka-state_test-605b	PUSH1_0x5b
...fork_Osaka-state_test-615b5b	PUSH2_0x5b5b
...fork_Osaka-state_test-605b5b
...fork_Osaka-state_test-615b5b5b
...fork_Osaka-blockchain_test_from_state_test-00	STOP
...fork_Osaka-blockchain_test_from_state_test-5b	JUMPDEST
...fork_Osaka-blockchain_test_from_state_test-605b	PUSH1_0x5b
...fork_Osaka-blockchain_test_from_state_test-615b5b	PUSH2_0x5b5b
...fork_Osaka-blockchain_test_from_state_test-605b5b
...fork_Osaka-blockchain_test_from_state_test-615b5b5b

test_worst_initcode_jumpdest_analysis()¶

Parametrized Test Cases¶

`test_worst_initcode_jumpdest_analysis()`¶