Gas Optimizations

[code423n4]

Internal Function Called Only Once Can be Inlined

Issue

Certain function is defined even though it is called only once. Inline it instead to where it is called to avoid usage of extra gas.

PoC

Total of 2 instances found.

1. createEscrow() of Market.sol This function called only once at line 247 https://github.com/code-423n4/2022-10-inverse/blob/3e81f0f5908ea99b36e6ab72f13488bbfe622183/src/Market.sol#L226 https://github.com/code-423n4/2022-10-inverse/blob/3e81f0f5908ea99b36e6ab72f13488bbfe622183/src/Market.sol#L247

2. getWithdrawalLimitInternal() of Market.sol This function called only once at line 461 https://github.com/code-423n4/2022-10-inverse/blob/3e81f0f5908ea99b36e6ab72f13488bbfe622183/src/Market.sol#L353 https://github.com/code-423n4/2022-10-inverse/blob/3e81f0f5908ea99b36e6ab72f13488bbfe622183/src/Market.sol#L461

Mitigation

I recommend to not define above functions and instead inline it at place it is called.

 

Boolean Comparisons

Issue

It is more gas expensive to compare boolean with "variable == true" or "variable == false" than directly checking the returned boolean value.

PoC

./DBR.sol:350:        require(minters[msg.sender] == true || msg.sender == operator, "ONLY MINTERS OR OPERATOR");

Mitigation

Simply check by returned boolean value. Change it to

require(!somethinghere)

 

Use require instead of &&

Issue

When there are multiple conditions in require statement, break down the require statement into multiple require statements instead of using && can save gas.

PoC

./DBR.sol:249:            require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNER");
./Market.sol:75:        require(_liquidationIncentiveBps > 0 && _liquidationIncentiveBps < 10000, "Invalid liquidation incentive");
./Market.sol:162:        require(_liquidationFactorBps > 0 && _liquidationFactorBps <= 10000, "Invalid liquidation factor");
./Market.sol:173:        require(_replenishmentIncentiveBps > 0 && _replenishmentIncentiveBps < 10000, "Invalid replenishment incentive");
./Market.sol:184:        require(_liquidationIncentiveBps > 0 && _liquidationIncentiveBps + liquidationFeeBps < 10000, "Invalid liquidation incentive");
./Market.sol:195:        require(_liquidationFeeBps > 0 && _liquidationFeeBps + liquidationIncentiveBps < 10000, "Invalid liquidation fee");
./Market.sol:448:            require(recoveredAddress != address(0) && recoveredAddress == from, "INVALID_SIGNER");
./Market.sol:512:            require(recoveredAddress != address(0) && recoveredAddress == from, "INVALID_SIGNER");

Mitigation

Break down into several require statement.

 

[c4-judge]

0xean marked the issue as grade-c