FIAT DAO veFDT contest - 0xSmartContract's results

1-Use assembly to write address storage values

Context: VotingEscrow.sol#L139-L143 VotingEscrow.sol#L146-L150 VotingEscrow.sol#L153-L157

Proof Of Concept The optimizer was turned on and set to 10000 runs

contract GasTest is DSTest {
    Contract0 c0;
    Contract1 c1;

    function setUp() public {
        c0 = new Contract0();
        c1 = new Contract1();

    }

    function testGas() public {
        c0.admin(0x5B38Da6a701c568545dCfcB03FcB875f56beddC4);
        c1.admin(0x5B38Da6a701c568545dCfcB03FcB875f56beddC4);
    }
}


contract Contract0 {
    address public foo;

    function admin(address _implementation) external  {
        foo = _implementation;
    }
}

contract Contract1 { 
    address public foo;

    function admin(address _implementation) external  {
        assembly {
            sstore(foo.slot, _implementation)
        }
    }

}

Gas Report

╭───────────────────────────────────────────┬─────────────────┬───────┬────────┬───────┬─────────╮
│ src/test/GasTest.t.sol:Contract0 contract ┆                 ┆       ┆        ┆       ┆         │
╞═══════════════════════════════════════════╪═════════════════╪═══════╪════════╪═══════╪═════════╡
│ Deployment Cost                           ┆ Deployment Size ┆       ┆        ┆       ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ 66917                                     ┆ 366             ┆       ┆        ┆       ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ Function Name                             ┆ min             ┆ avg   ┆ median ┆ max   ┆ # calls │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ admin                                     ┆ 22363           ┆ 22363 ┆ 22363  ┆ 22363 ┆ 1       │
╰───────────────────────────────────────────┴─────────────────┴───────┴────────┴───────┴─────────╯
╭───────────────────────────────────────────┬─────────────────┬───────┬────────┬───────┬─────────╮
│ src/test/GasTest.t.sol:Contract1 contract ┆                 ┆       ┆        ┆       ┆         │
╞═══════════════════════════════════════════╪═════════════════╪═══════╪════════╪═══════╪═════════╡
│ Deployment Cost                           ┆ Deployment Size ┆       ┆        ┆       ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ 51705                                     ┆ 290             ┆       ┆        ┆       ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ Function Name                             ┆ min             ┆ avg   ┆ median ┆ max   ┆ # calls │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ admin                                     ┆ 22324           ┆ 22324 ┆ 22324  ┆ 22324 ┆ 1       │
╰───────────────────────────────────────────┴─────────────────┴───────┴────────┴───────┴─────────╯

2-Setting The Constructor To Payable

Context:

VotingEscrow.sol#L100 Blocklist.sol#L14

Description: You can cut out 10 opcodes in the creation-time EVM bytecode if you declare a constructor payable. Making the constructor payable eliminates the need for an initial check of msg.value == 0 and saves 21 gas on deployment with no security risks.

Proof Of Concept https://forum.openzeppelin.com/t/a-collection-of-gas-optimisation-tricks/19966/5?u=pcaversaccio The optimizer was turned on and set to 10000 runs

contract GasTest is DSTest {
    Contract0 c0;
    Contract1 c1;

    function setUp() public {
        c0 = new Contract0();
        c1 = new Contract1();
    }
}


contract Contract0 {
    uint256 public dummy;

    constructor() payable {
        dummy = 1;
    }
}


contract Contract1 {
    uint256 public dummy;

    constructor() {
        dummy = 1;
    }
}

Gas Report

╭───────────────────────────────────────────┬─────────────────┬──────┬────────┬──────┬─────────╮
│ src/test/GasTest.t.sol:Contract0 contract ┆                 ┆      ┆        ┆      ┆         │
╞═══════════════════════════════════════════╪═════════════════╪══════╪════════╪══════╪═════════╡
│ Deployment Cost                           ┆ Deployment Size ┆      ┆        ┆      ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ 57569                                     ┆ 200             ┆      ┆        ┆      ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
╰───────────────────────────────────────────┴─────────────────┴──────┴────────┴──────┴─────────╯
╭───────────────────────────────────────────┬─────────────────┬──────┬────────┬──────┬─────────╮
│ src/test/GasTest.t.sol:Contract1 contract ┆                 ┆      ┆        ┆      ┆         │
╞═══════════════════════════════════════════╪═════════════════╪══════╪════════╪══════╪═════════╡
│ Deployment Cost                           ┆ Deployment Size ┆      ┆        ┆      ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ 57593                                     ┆ 213             ┆      ┆        ┆      ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
╰───────────────────────────────────────────┴─────────────────┴──────┴────────┴──────┴─────────╯

3-Function Ordering via Method ID

Context:  All Contracts

Description: Contracts most called functions could simply save gas by function ordering via Method ID. Calling a function at runtime will be cheaper if the function is positioned earlier in the order (has a relatively lower Method ID) because 22 gas are added to the cost of a function for every position that came before it. The caller can save on gas if you prioritize most called functions.

Recommendation: Find a lower method ID name for the most called functions for example Call() vs. Call1() is cheaper by 22 gas. For example, the function IDs in the NFTCollectionFactory.sol contract will be the most used; A lower method ID may be given

Sighash   |   Function Signature
========================
23792279  =>  lockEnd(address)
f2fde38b  =>  transferOwnership(address)
4684532e  =>  updateBlocklist(address)
e4890711  =>  updatePenaltyRecipient(address)
a69df4b5  =>  unlock()
391cc9f6  =>  forceUndelegate(address)
c4698ee5  =>  getLastUserPoint(address)
da3868f5  =>  _checkpoint(address,LockedBalance,LockedBalance)
c2c4c5c1  =>  checkpoint()
b52c05fe  =>  createLock(uint256,uint256)
15456eba  =>  increaseAmount(uint256)
7c616fe6  =>  increaseUnlockTime(uint256)
3ccfd60b  =>  withdraw()
5c19a95c  =>  delegate(address)
59b462f6  =>  _delegate(address,LockedBalance,int128,LockAction)
75c54eda  =>  quitLock()
159dbfad  =>  _calculatePenaltyRate(uint256)
39f22f6b  =>  collectPenalty()
2f0f3990  =>  _copyLock(LockedBalance)
9a0ba4fb  =>  _floorToWeek(uint256)
5baf280e  =>  _findBlockEpoch(uint256,uint256)
93cb2ee7  =>  _findUserBlockEpoch(address,uint256)
70a08231  =>  balanceOf(address)
4ee2cd7e  =>  balanceOfAt(address,uint256)
31c2182d  =>  _supplyAt(Point256,uint256)
18160ddd  =>  totalSupply()
981b24d0  =>  totalSupplyAt(uint256)

Proof of Consept: https://coinsbench.com/advanced-gas-optimizations-tips-for-solidity-85c47f413dc5

4- Functions Guaranteed to Revert When Callled By Normal Users Can Be Marked Payable

Context: 

VotingEscrow.sol#L139 VotingEscrow.sol#L146 VotingEscrow.sol#L161

Description: If a function modifier such as onlyOwner is used, the function will revert if a normal user tries to pay the function. Marking the function as payable will lower the gas cost for legitimate callers because the compiler will not include checks for whether a payment was provided. The extra opcodes avoided are CALLVALUE(2),DUP1(3),ISZERO(3),PUSH2(3),JUMPI(10),PUSH1(3),DUP1(3),REVERT(0),JUMPDEST(1),POP(2), which costs an average of about 21 gas per call to the function, in addition to the extra deployment cost

Recommendation: Functions guaranteed to revert when called by normal users can be marked payable (for only onlyowner functions)

Proof Of Concept The optimizer was turned on and set to 10000 runs

contract GasTest is DSTest {
    Contract0 c0;
    Contract1 c1;

    function setUp() public {
        c0 = new Contract0();
        c1 = new Contract1();

    }

    function testGas() public {
        c0.foo();
        c1.foo();
    }
}


contract Contract0 {
    uint256 versionNFTDropCollection;

    function foo() external  {
       versionNFTDropCollection++;
    }
}

contract Contract1 {
    uint256 versionNFTDropCollection;

    function foo() external payable {
        versionNFTDropCollection++;
   }
}

Gas Report

╭───────────────────────────────────────────┬─────────────────┬───────┬────────┬───────┬─────────╮
│ src/test/GasTest.t.sol:Contract0 contract ┆                 ┆       ┆        ┆       ┆         │
╞═══════════════════════════════════════════╪═════════════════╪═══════╪════════╪═══════╪═════════╡
│ Deployment Cost                           ┆ Deployment Size ┆       ┆        ┆       ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ 44293                                     ┆ 252             ┆       ┆        ┆       ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ Function Name                             ┆ min             ┆ avg   ┆ median ┆ max   ┆ # calls │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ foo                                       ┆ 22308           ┆ 22308 ┆ 22308  ┆ 22308 ┆ 1       │
╰───────────────────────────────────────────┴─────────────────┴───────┴────────┴───────┴─────────╯
╭───────────────────────────────────────────┬─────────────────┬───────┬────────┬───────┬─────────╮
│ src/test/GasTest.t.sol:Contract1 contract ┆                 ┆       ┆        ┆       ┆         │
╞═══════════════════════════════════════════╪═════════════════╪═══════╪════════╪═══════╪═════════╡
│ Deployment Cost                           ┆ Deployment Size ┆       ┆        ┆       ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ 41893                                     ┆ 240             ┆       ┆        ┆       ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ Function Name                             ┆ min             ┆ avg   ┆ median ┆ max   ┆ # calls │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ foo                                       ┆ 22284           ┆ 22284 ┆ 22284  ┆ 22284 ┆ 1       │
╰───────────────────────────────────────────┴─────────────────┴───────┴────────┴───────┴─────────╯

5-Use Custom Errors Rather Than Revert() / Require() Strings to Save Deployment Gas

Context:  all requires

Description: Custom errors are available from solidity version 0.8.4. Custom errors save ~50 gas each time they’re hitby avoiding having to allocate and store the revert string. Not defining the strings also save deployment gas https://blog.soliditylang.org/2021/04/21/custom-errors/

Proof Of Concept The optimizer was turned on and set to 10000 runs

contract GasTest is DSTest {
    Contract0 c0;
    Contract1 c1;

    function setUp() public {
        c0 = new Contract0();
        c1 = new Contract1();
    }

    function testGas() public {
        c0.foo();
        c1.foo();
    }
}


contract Contract0 {
    uint256 versionNFTDropCollection;
    error NFT_Collection_Error();

    function foo() external  {
      if (versionNFTDropCollection != 0) {
            revert NFT_Collection_Error();
        }
}
}

contract Contract1 {
    uint256 versionNFTDropCollection;

    function foo() external {
        require(versionNFTDropCollection != 0, "NFTCollection error");
   }
}

Gas Report

╭───────────────────────────────────────────┬─────────────────┬──────┬────────┬──────┬─────────╮
│ src/test/GasTest.t.sol:Contract0 contract ┆                 ┆      ┆        ┆      ┆         │
╞═══════════════════════════════════════════╪═════════════════╪══════╪════════╪══════╪═════════╡
│ Deployment Cost                           ┆ Deployment Size ┆      ┆        ┆      ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ 33287                                     ┆ 196             ┆      ┆        ┆      ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ Function Name                             ┆ min             ┆ avg  ┆ median ┆ max  ┆ # calls │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ foo                                       ┆ 2242            ┆ 2242 ┆ 2242   ┆ 2242 ┆ 1       │
╰───────────────────────────────────────────┴─────────────────┴──────┴────────┴──────┴─────────╯
╭───────────────────────────────────────────┬─────────────────┬──────┬────────┬──────┬─────────╮
│ src/test/GasTest.t.sol:Contract1 contract ┆                 ┆      ┆        ┆      ┆         │
╞═══════════════════════════════════════════╪═════════════════╪══════╪════════╪══════╪═════════╡
│ Deployment Cost                           ┆ Deployment Size ┆      ┆        ┆      ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ 41693                                     ┆ 239             ┆      ┆        ┆      ┆         │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ Function Name                             ┆ min             ┆ avg  ┆ median ┆ max  ┆ # calls │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
│ foo                                       ┆ 2310            ┆ 2310 ┆ 2310   ┆ 2310 ┆ 1       │
╰───────────────────────────────────────────┴─────────────────┴──────┴────────┴──────┴─────────╯