Redacted Cartel contest - dharma09's results

1.OR CONDITIONS COST LESS THAN THEIR EQUIVALENT, AND CONDITIONS (“NOT(SOMETHING IS FALSE)” COSTS LESS THAN “EVERYTHING IS TRUE”)

the equivalent of (a && b) is !(!a || !b)

Even with the 10k Optimizer enabled, OR conditions cost less than their equivalent AND conditions.

Proof of Concept.

Compare in Remix this example contract’s 2 diffs (or any test contract of your choice, as experimentation always shows the same results).

pragma solidity 0.8.13;  
contract Test {  
bool isOpen;  
bool channelPreviouslyOpen;  
  
function boolTest() external view returns (uint) {  
- if (isOpen && !channelPreviouslyOpen) {  
+ if (!(!isOpen || channelPreviouslyOpen)) {  
return 1;  
- } else if (!isOpen && channelPreviouslyOpen) {  
+ } else if (!(isOpen || !channelPreviouslyOpen)) {  
return 2;  
}  
}  
function setBools(bool _isOpen, bool _channelPreviouslyOpen) external {  
isOpen = _isOpen;  
channelPreviouslyOpen= _channelPreviouslyOpen;  
}  
}  

effectively saving 12 gas.

Affected Code

It’s possible to save a significant amount of gas by replacing the && conditions with their || equivalent in the solution. PirexRewards.sol#L385 PxGmxReward.sol#L115

MITIGATION

Use if !(globalRewards == 0 || userRewards == 0)instead of if (globalRewards != 0 && userRewards != 0)

2.Constant expressions are re-calculated each time it is in use, costing an extra 97 gas than a constant every time they are called.

PROOF OF CONCEPT

Instances include:

MITIGATION

Mark these as immutable instead of constant PxERC20.sol#

#L9:    bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
#L10:   bytes32  public constant BURNER_ROLE =  keccak256("BURNER_ROLE");

3. functions called by only the owner it's should be declared external instead of public

PirexGmx.sol

#L895 : function clearVoteDelegate() public onlyOwner {

MITIGATION

Mark these as external instead of public