Handle

Dravee

Vulnerability details

Impact

It's possible to save gas by optimizing the checks in conditional statements (if, else if and else). This would save a few opcodes and avoid redundant checks.

Proof of Concept

In PoolTemplate.sol:worth(), the code is as follows:

799:     function worth(uint256 _value) public view returns (uint256 _amount) {
800:         uint256 _supply = totalSupply();
801:         uint256 _originalLiquidity = originalLiquidity();
802:         if (_supply > 0 && _originalLiquidity > 0) {
803:             _amount = (_value * _supply) / _originalLiquidity;
804:         } else if (_supply > 0 && _originalLiquidity == 0) {
805:             _amount = _value * _supply;
806:         } else {
807:             _amount = _value;
808:         }
809:     }

The conditions checks can be optimized with the following (read the @audit-info comments for further information):

    function worth(uint256 _value) public view returns (uint256 _amount) {
        uint256 _supply = totalSupply();
        uint256 _originalLiquidity = originalLiquidity();
        if (_supply == 0) {
            _amount = _value;
        } else if (_originalLiquidity == 0) {
            _amount = _value * _supply;
        } else {
            _amount = (_value * _supply) / _originalLiquidity;
        }
    }

Tools Used

VS Code

Recommended Mitigation Steps

Compact conditions in mentioned logic statements

//new one function worth_1() public pure returns (uint256) { uint256 _value = 100; uint256 _supply = 1; uint256 _originalLiquidity = 1; uint256 _amount; if (_supply == 0) { _amount = _value; } else if (_originalLiquidity == 0) { _amount = _value * _supply; } else { _amount = (_value * _supply) / _originalLiquidity; } return _amount; } //current one function worth_2() public pure returns (uint256) { uint256 _value = 100; uint256 _supply = 1; uint256 _originalLiquidity = 1; uint256 _amount; if (_supply > 0 && _originalLiquidity > 0) { _amount = (_value * _supply) / _originalLiquidity; } else if (_supply > 0 && _originalLiquidity == 0) { _amount = _value * _supply; } else { _amount = _value; } return _amount; } //little bit of gas opt from worth_2 function worth_3() public pure returns (uint256) { uint256 _value = 100; uint256 _supply = 1; uint256 _originalLiquidity = 1; uint256 _amount; if (_supply != 0 && _originalLiquidity != 0) { _amount = (_value * _supply) / _originalLiquidity; } else if (_supply != 0 && _originalLiquidity == 0) { _amount = _value * _supply; } else { _amount = _value; } return _amount; }

code-423n4 / 2022-01-insure-findings