Cache array length in for loops can save gas

[code423n4]

Handle

WatchPug

Vulnerability details

Reading array length at each iteration of the loop takes 6 gas (3 for mload and 3 to place memory_offset) in the stack.

Caching the array length in the stack saves around 3 gas per iteration.

Instances include:

• AuctionParticipant.sol#outstandingArbTokens()

  https://github.com/code-423n4/2021-11-malt/blob/c3a204a2c0f7c653c6c2dda9f4563fd1dc1cecf3/src/contracts/AuctionParticipant.sol#L107

• MiningService.sol#balanceOfRewards()

  https://github.com/code-423n4/2021-11-malt/blob/c3a204a2c0f7c653c6c2dda9f4563fd1dc1cecf3/src/contracts/MiningService.sol#L48

• TransferService.sol#removeVerifier()

  https://github.com/code-423n4/2021-11-malt/blob/c3a204a2c0f7c653c6c2dda9f4563fd1dc1cecf3/src/contracts/TransferService.sol#L87

• Auction.sol#getAccountCommitments()

  https://github.com/code-423n4/2021-11-malt/blob/c3a204a2c0f7c653c6c2dda9f4563fd1dc1cecf3/src/contracts/Auction.sol#L407

[0xScotch]

#106