Gas Optimizations

[code423n4]

Add unchecked {} for subtractions where the operands cannot underflow because of a previous require() or if-statement

since checking for underflow is already done in previous require() or if-statement, unchecked the subtractions saves gas for the operation. require(a <= b); x = b - a => require(a <= b); unchecked { x = b - a } There are some instances for this issue: https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L319 https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L385 https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L431

<X> = <X> + <Y> is cheaper than <X> += <Y>

For operation like addition or subtraction in state variable, <X> = <X> + <Y> is more efficient than <X> += <Y>. There are some instances for this issue : https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L268 https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L401 https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L445

Duplicated check for user should be refactored to a modifier or function

By refactored the require()/revert() to a modifier or function saves deployment gas. There are 4 checks for creator in this contract :

https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L376 https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L422 https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L459 https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L491

I suggest to refactored the code below to a modifier or function to saves deployment gas. if(msg.sender != creator) revert Errors.NotPledgeCreator();

Redundant revert() check in addMultipleRewardToken() function

In the addMultipleRewardToken() function, minRewardsPerSecond.length should not be zero. So if length is 0, the second revert() is enough, no need to check using first revert(), it saves gas. So its better to remove the first revert() : if (length == 0) revert error.EmptyArray(); https://github.com/code-423n4/2022-10-paladin/blob/main/contracts/WardenPledge.sol#L544-L545

[c4-judge]

kirk-baird marked the issue as grade-b