Gas Optimizations

[code423n4]

GAS OPTIMIZATIONS

• Following math operations can be carried out unchecked since the conditions are checked on previous LOCs and will not underflow; Vault.sol#L125- Condition checked on Vault.sol#L122 Vault.sol#L130-L131 - Condition checked on Vault.sol#L127 Vault.sol#L141 - Condition checked on Vault.sol#L122-L134 Vault.sol#L423 - Condition checked on Vault.sol#L421 Vault.sol#L440 - Condition checked on Vault.sol#L437 Vault.sol#L444 - Condition checked on Vault.sol#L443 Vault.sol#L452 - Condition checked on Vault.sol#L451 Vault.sol#L482 - Condition checked on the same line Vault.sol#L591 - Condition checked on Vault.sol#L589 Vault.sol#L595 - Condition checked on Vault.sol#L593 Vault.sol#L600 - Condition checked on Vault.sol#L599 Vault.sol#L605 - Condition checked on Vault.sol#L603 Vault.sol#L637 - Condition checked on Vault.sol#L635 Vault.sol#L688 - Profit condition Vault.sol#L695 - Condition checked on Vault.sol#L692-L693 Vault.sol#L781 - Condition checked on the same line as a ternary operator

• Vault.sol#L581 calls the function again inside same contract creating unnecessary function overloading (strategy.harvest();). Since it's not inheriting a function in outer contracts, function logic can be inlined directly in this line in order to save gas.

• At Vault.sol#L323, _handleExcessDebt() is called which initiates a function triggering inside the same contract (not inheriting other contracts). However, the function logic can be inlined to executeDebtLimit() by passing required params/state variables to prevent SLOADs.

• Caching .length inside loop functions will save gas, located at StakerVault.sol#L260 , RoleManager.sol#L80 ,TopUpActipn.sol#188 , TopUpKeeperHelper.sol#L43 , TopUpKeeperHelper.sol#L46 , TopUpKeeperHelper.sol#L72 , CompoundHandler.sol#135 , CTokenRegistry.sol#L61 , ConvexStrategyBase.sol#L313 , ConvexStrategyBase.sol#L380

• Using unchecked {++i} instead of i++ will save gas.

• Using immutable instead of constant variables will save gas.

• Choosing either named return or explicit instead of specifying both may reduce gas due to unnecessary bytecode introduced. There is inconsistent use of implicit named return variables across the entire codebase which makes readability and maintainability hard.

• Use bytes32 instead of string to save gas whenever possible. String is a dynamic data structure and therefore is more gas consuming then bytes32. You could use bytes32 instead of string in the following places: LiquidityPool.sol#L71 , PoolFactory.sol#L47-L48

[chase-manning]

Appears to be an exact duplicate of #154