Fe port certificate

Dai

Port source ports/dai, runtime code hash 0x2ac45b43d07de9b28abc49869c7bbe0847b5b97901a34dbd4a2f545c751d51f0 (2847 bytes), in place of the deployed code with hash 0x4e36f96ee1667a663dfaac57c4d185a0e369a3a217e0079d49620f34f85d1ac7 (7904 bytes). Blocks /root/v2blocks/0x192d500 to /root/v2blocks/0x192d5c7.

No behavior difference: every transaction that ran the port, every mutation of them and every random call behaved as on the deployed code.

Mainnet, as it happenedpassed
Mainnet, mutatedpassed
Random callspassed
Mutants: the unchanged portpassed

Mainnet, as it happened

Each transaction of the blocks ran on its own mainnet pre-state, with the port in place of every account holding the deployed code, and was compared with the chain: status, logs, every balance, nonce and storage slot. Only gas may differ.

Blocks200
Transactions69643
Transactions that ran the port10562
Identical to the chain10540
Differ where other code read the gas left22
  of which part at or under that code22
Differ where other code read code hashes0
Only the deployed code ran out of gas0
Behave differently0

Gas per call in identical transactions

FunctionIn the port's sourceCallsDeployedPortChange
Permitsrc/lib.fe:26625297652267-1.3%
TransferFromsrc/lib.fe:2131661441113835-3.9%
BalanceOfsrc/lib.fe:18857112991137-12.4%
Transfersrc/lib.fe:208105512745327017-1.5%
Mintsrc/lib.fe:224301730817033-1.5%
Approvesrc/lib.fe:247931869718459-1.2%
Decimalssrc/lib.fe:1806240172-28.3%
Allowancesrc/lib.fe:1923823082134-7.5%
Burnsrc/lib.fe:2322994219051-3.9%

Mainnet, mutated

Each transaction that touched the deployed code ran again with its calldata changed, or with one call into the contract changed in flight, on both codes, gas free.

Transactions10562
Runs211240
Identical211142
Differ where other code read the gas left or code hashes92
  of which code hashes10
  of the rest, part at or under the code that read the gas left82
Only the deployed code ran out of gas6
Differ after an address-shaped word got upper bits0
Differ after the calldata was cut short0
Differ0

The port ran 1050 of its 1675 instructions (62.6%) in these runs.

Random calls

1,000 sessions of up to 60 random calls each, against both codes in step.

Well-formed calls49464
Well-formed calls that differ0
Calls with short calldata that differ0
Calls with dirty addresses that differ0
Invariants broken0

The port ran 1596 of its 1675 instructions (95.2%).

How sharp the checks are

Mutants of the port's source, one operator changed each, built with fe and put through random calls and then mutations of the first ten blocks. The unchanged port passed the same checks first.

Operators in the source21
Mutants built21
Killed by random calls21
Killed by mainnet mutations0
Survived0

100% killed.

Made by fevm-replay certify, written in Fe and running fevm, the EVM written in Fe.