QuickSwap and StellaSwap contest - ReyAdmirado's results

1. <x> += <y> costs more gas than <x> = <x> + <y> for state variables

• AlgebraPool.sol#L257
• AlgebraPool.sol#L258
• AlgebraPool.sol#L804
• AlgebraPool.sol#L811
• AlgebraPool.sol#L814
• AlgebraPool.sol#L931
• AlgebraPool.sol#L945
• AlgebraPool.sol#L801
• AlgebraPool.sol#L810
• AlgebraPool.sol#L922
• AlgebraPool.sol#L936

2. not using the named return variables when a function returns, wastes deployment gas

• AlgebraPool.sol#L83

• AlgebraPool.sol#L108

• AlgebraPool.sol#L175

• AlgebraPool.sol#L403

• AlgebraPool.sol#L557

• AlgebraPool.sol#L570

• DataStorageOperator.sol#L99

• DataStorageOperator.sol#L115

• DataStorageOperator.sol#L126

• DataStorageOperator.sol#L135

• DataStorageOperator.sol#L155

3. splitting require() statements that use && saves gas

• AlgebraFactory.sol#L110

• AlgebraPool.sol#L739

• AlgebraPool.sol#L743

• AlgebraPool.sol#L953

• AlgebraPool.sol#L968

• DataStorageOperator.sol#L46

4. using > 0 costs more gas than != 0 when used on a uint in a require() statement

• AlgebraPool.sol#L224
• AlgebraPool.sol#L434
• AlgebraPool.sol#L469
• AlgebraPool.sol#L898

5. require() or revert() statements that check input arguments should be at the top of the function

• DataStorageOperator.sol#L42

6. use a more recent version of solidity

Use a solidity version of at least 0.8.0 to get overflow protection without SafeMath 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 Use a solidity version of at least 0.8.13 to get the ability to use using for with a list of free functions

7. using calldata instead of memory for read-only arguments in external functions saves gas

• DataStorageOperator.sol#L90

8. using bool for storage incurs overhead

https://github.com/OpenZeppelin/openzeppelin-contracts/blob/58f635312aa21f947cae5f8578638a85aa2519f5/contracts/security/ReentrancyGuard.sol#L23-L27 Use uint256(1) and uint256(2) for true/false to avoid a Gwarmaccess (100 gas) for the extra SLOAD, and to avoid Gsset (20000 gas) when changing from ‘false’ to ‘true’, after having been ‘true’ in the past

• AlgebraPool.sol#L293
• AlgebraPool.sol#L294
• AlgebraPool.sol#L591
• AlgebraPool.sol#L629
• AlgebraPool.sol#L704
• AlgebraPool.sol#L728

9. internal functions only called once can be inlined to save gas

Not inlining costs 20 to 40 gas because of two extra JUMP instructions and additional stack operations needed for function calls.

• AlgebraPool.sol#L215

10. abi.encode() is less efficient than abi.encodepacked()

• AlgebraFactory.sol#L123

• AlgebraPoolDeployer.sol#L51