Paladin - Warden Pledges contest - Amithuddar's results

1)X = X + Y OR X = X - Y CAN BE USED INSTEAD OF X += Y OR X -= Y

x = x + y or x = x - y costs less gas than x += y or x -= y. For example, v += 27 can be changed to v = v + 27 in the following code.

File: 2022-10-paladin\contracts\WardenPledge.sol 340,56: pledgeAvailableRewardAmounts[vars.newPledgeID] += vars.totalRewardAmount; 401,48: pledgeAvailableRewardAmounts[pledgeId] += totalRewardAmount; 445,48: pledgeAvailableRewardAmounts[pledgeId] += totalRewardAmount; 268,48: pledgeAvailableRewardAmounts[pledgeId] -= rewardAmount;

2)USE A MORE RECENT VERSION OF SOLIDITY

Use a solidity version of at least 0.8.2 to get compiler automatic inlining

Use a solidity version of at least 0.8.3 to get better struct packing and cheaper multiple storage reads

Use a solidity version of at least 0.8.4 to get custom errors, which are cheaper at deployment than revert()/require() strings

Use a solidity version of at least 0.8.10 to have external calls skip contract existence checks if the external call has a return value

File: 2022-10-paladin\contracts\interfaces\IBoostV2.sol: 1 // SPDX-License-Identifier: MIT 2: pragma solidity ^0.8.4; 3

File: 2022-10-paladin\contracts\interfaces\IVotingEscrow.sol: 1 // SPDX-License-Identifier: MIT 2: pragma solidity ^0.8.4; 3

File: 2022-10-paladin\contracts\oz\interfaces\IERC20.sol: 3
4: pragma solidity ^0.8.0; 5

File: 2022-10-paladin\contracts\oz\libraries\SafeERC20.sol: 2
3: pragma solidity ^0.8.0; 4

File: 2022-10-paladin\contracts\oz\utils\Address.sol: 3
4: pragma solidity ^0.8.1; 5

File: 2022-10-paladin\contracts\oz\utils\Context.sol: 3
4: pragma solidity ^0.8.0; 5

File: 2022-10-paladin\contracts\oz\utils\Ownable.sol: 3
4: pragma solidity ^0.8.0; 5

File: 2022-10-paladin\contracts\oz\utils\Pausable.sol: 3
4: pragma solidity ^0.8.0; 5

File: 2022-10-paladin\contracts\oz\utils\ReentrancyGuard.sol: 3
4: pragma solidity ^0.8.0; 5

File: 2022-10-paladin\contracts\utils\Errors.sol: 1 // SPDX-License-Identifier: MIT 2: pragma solidity ^0.8.4; 3

3)Division by two should use bit shifting

<x> / 2 is the same as <x> >> 1. While the compiler uses the SHR opcode to accomplish both, the version that uses division incurs an overhead of 20 gas due to JUMPs to and from a compiler utility function that introduces checks which can be avoided by using unchecked {} around the division by two

File: 2022-10-paladin\contracts\WardenPledge.sol 263,72: uint256 totalDelegatedAmount = ((bias * boostDuration) + bias) / 2;

4)Multiple address mappings can be combined into a single mapping of an address to a struct

Multiple address mappings can be combined into a single mapping of an address to a struct, where appropriate saves a storage slot for the mapping. Depending on the circumstances and sizes of types, can avoid a Gsset (20000 gas) per mapping combined. Reads and subsequent writes can also be cheaper when a function requires both values and they both fit in the same storage slot.

File: 2022-10-paladin\contracts\WardenPledge.sol 50,5: mapping(uint256 => address) public pledgeOwner; 52,5: mapping(address => uint256[]) public ownerPledges; 56,5: mapping(uint256 => uint256) public pledgeAvailableRewardAmounts; 67,5: mapping(address => uint256) public minAmountRewardToken;

5)Use assembly to check for address(0) Impact

Saves 6 gas per instance if using assembly to check for zero address

File: 2022-10-paladin\contracts\WardenPledge.sol 310,24: if(receiver == address(0) || rewardToken == address(0)) revert Errors.ZeroAddress(); 310,53: if(receiver == address(0) || rewardToken == address(0)) revert Errors.ZeroAddress(); 460,24: if(receiver == address(0)) revert Errors.ZeroAddress(); 492,24: if(receiver == address(0)) revert Errors.ZeroAddress(); 527,21: if(token == address(0)) revert Errors.ZeroAddress(); 571,21: if(token == address(0)) revert Errors.ZeroAddress(); 586,21: if(token == address(0)) revert Errors.ZeroAddress(); 600,21: if(chest == address(0)) revert Errors.ZeroAddress();

File: 2022-10-paladin\contracts\oz\utils\Ownable.sol

70,29: require(newOwner != address(0), "Ownable: new owner is the zero address");

File: 2022-10-paladin\contracts\utils\Owner.sol 20,24: if(newOwner == address(0)) revert OwnerZeroAddress();

6)Use calldata instead of memory for function parameters type :

If a reference type function parameter is read-only, it is cheaper in gas to use calldata instead of memory. Calldata is a non-modifiable, non-persistent area where function arguments are stored, and behaves mostly like memory.

There are 5 instances of this issue File: 2022-10-paladin\contracts\oz\libraries\SafeERC20.sol 87,54: function _callOptionalReturn(IERC20 token, bytes memory data) private {

File: 2022-10-paladin\contracts\oz\utils\Address.sol 85,49: function functionCall(address target, bytes memory data) internal returns (bytes memory) { 85,86: function functionCall(address target, bytes memory data) internal returns (bytes memory) {

147,55: function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { 147,97: function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {

174,57: function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) { 174,94: function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {