Yieldy contest - s3cunda's results

gas optimization in Yiedly.sol

in these two functions below, since creditAmout&allowance was already checked in previous require statement, so the next-line algo can use unchecked modifier to reduce gas consumption.

    function transfer(address _to, uint256 _value)
        public
        override
        returns (bool)
    {
        require(_to != address(0), "Invalid address");

        uint256 creditAmount = _value * rebasingCreditsPerToken;
        require(creditAmount <= creditBalances[msg.sender], "Not enough funds");//@s3cunda: gas
//use unchecked
        creditBalances[msg.sender] = creditBalances[msg.sender] - creditAmount;
        creditBalances[_to] = creditBalances[_to] + creditAmount;
        emit Transfer(msg.sender, _to, _value);
        return true;
    }

    /**
        @notice transfer from address to address with amount
        @param _from address
        @param _to address
        @param _value uint
        @return bool
     */
    function transferFrom(
        address _from,
        address _to,
        uint256 _value
    ) public override returns (bool) {
        require(_allowances[_from][msg.sender] >= _value, "Allowance too low");//@s3cunda: gas
//use unchecked
        uint256 newValue = _allowances[_from][msg.sender] - _value;
        _allowances[_from][msg.sender] = newValue;
        emit Approval(_from, msg.sender, newValue);

        uint256 creditAmount = creditsForTokenBalance(_value);
        creditBalances[_from] = creditBalances[_from] - creditAmount;
        creditBalances[_to] = creditBalances[_to] + creditAmount;
        emit Transfer(_from, _to, _value);

        return true;
    }