FIAT DAO veFDT contest - 0xHarry's results

Word packing should be done structs that are stored in storage: From:

  struct Point {
        int128 bias;
        int128 slope;
        uint256 ts;
        uint256 blk;
    }

to

  struct Point {
        int128 bias;
        int128 slope;
        uint128 ts; // @audit will be safe for hundre'ts of years 
        uint129 blk; // @audit blocks increment slower than seconds
    }

From:

    struct LockedBalance {
        int128 amount;
        uint256 end;
        int128 delegated;
        address delegatee;
    }

to

    struct LockedBalance {
        int128 amount;
        int128 delegated;
        uint96 end;  // @audit will be safe for hundreds of years, change order to pack unit with address
        address delegatee;
    }

No need to zero initialize uint/int as non-assigned values are 0. Found in: https://github.com/code-423n4/2022-08-fiatdao/blob/fece3bdb79ccacb501099c24b60312cd0b2e4bb2/contracts/VotingEscrow.sol#L229-L230 https://github.com/code-423n4/2022-08-fiatdao/blob/fece3bdb79ccacb501099c24b60312cd0b2e4bb2/contracts/VotingEscrow.sol#L298 https://github.com/code-423n4/2022-08-fiatdao/blob/fece3bdb79ccacb501099c24b60312cd0b2e4bb2/contracts/VotingEscrow.sol#L313 https://github.com/code-423n4/2022-08-fiatdao/blob/fece3bdb79ccacb501099c24b60312cd0b2e4bb2/contracts/VotingEscrow.sol#L714 https://github.com/code-423n4/2022-08-fiatdao/blob/fece3bdb79ccacb501099c24b60312cd0b2e4bb2/contracts/VotingEscrow.sol#L737 https://github.com/code-423n4/2022-08-fiatdao/blob/fece3bdb79ccacb501099c24b60312cd0b2e4bb2/contracts/VotingEscrow.sol#L793-L794 https://github.com/code-423n4/2022-08-fiatdao/blob/fece3bdb79ccacb501099c24b60312cd0b2e4bb2/contracts/VotingEscrow.sol#L889

Move storage read after if statement: https://github.com/code-423n4/2022-08-fiatdao/blob/fece3bdb79ccacb501099c24b60312cd0b2e4bb2/contracts/VotingEscrow.sol#L271

Change to newer solidity version >=0.8.4 and use Custom errors as they are more gas efficient. Because of how many require statements there are, switching to custom errors will have a non-neglectable impact on gas consumption.