Gas Optimizations

[code423n4]

Gas

I. pendingPenalty will be accessed unnecessarily if there's no penalty stored. To prevent continuous access of the state variable and it being updated to zero(already the default), check whether there's any penalty before resetting to zero.

AuraBalRewardPool.sol

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L197

Add the following lines to forwardPenalty() :

if (toForward>0){

 pendingPenalty = 0;
     } 

The same applies for :

AuraMerkleDrop.sol

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraMerkleDrop.sol#L151

II. epochIndex already caches the length of the epoch. Therefore, replace all reference to the state variable below with the local variable:

https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AuraLocker.sol#L334-L335

III.Utilise unchecked block to save gas

The calculation for penalty will always be the smallest of the two operands :

AuraMerkleDrop.sol

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraMerkleDrop.sol#L138

AuraBalRewardPool.sol

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L185

Remove AuraMath.sub() as the condition necessitates that rdata.periodFinish is the larger operand and will not underflow:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L866

AuraVestedEscrow.sol

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraVestedEscrow.sol#L162