FactoryDAO contest - Tomio's results

Title: Using != is more gas efficient

Proof of Concept: https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/FixedPricePassThruGate.sol#L51 https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/MerkleResistor.sol#L175

Recommended Mitigation Steps: Change to !=0

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Title: Using > is cheaper than >=

Proof of Concept: https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/FixedPricePassThruGate.sol#L48 https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/MerkleResistor.sol#L179

Recommended Mitigation Steps: just use > can save gas

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Title: unnecessary value set. the default value of uint is 0.

Proof of Concept: https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/MerkleDropFactory.sol#L17 https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/MerkleEligibility.sol#L31 https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/MerkleResistor.sol#L176

Recommended Mitigation Steps: remove 0 value can save gas

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Title: Caching .length for loop can save gas

Proof of Concept: https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/MerkleLib.sol#L22 https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/PermissionlessBasicPoolFactory.sol#L115

Recommended Mitigation Steps: Change to:

	uint256 Length = proof.length;
	for (uint i = 0; i < Length; i += 1) {

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Title: Using calldata on struct parameter

Proof of Concept: https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/PermissionlessBasicPoolFactory.sol#L95

Recommended Mitigation Steps: Using calldata to store struct data type can save gas

    uint[] calldata rewardsWeiPerSecondPerToken,

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Title: Using delete statement to empty pool.rewardFunding can save gas

Proof of Concept: https://github.com/fei-protocol/flywheel-v2/blob/77bfadf388db25cf5917d39cd9c0ad920f404aad/src/FlywheelCore.sol#L123 https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/PermissionlessBasicPoolFactory.sol#L268

Recommended Mitigation Steps: Change to:

    delete pool.rewardFunding[i];

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Title: Using += to increase value on var

Proof of Concept: https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/VoterID.sol#L130 https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/VoterID.sol#L140

Recommended Mitigation Steps: Change to:

    numIdentities += 1;
    balances[thisOwner] += 1;

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