Rubicon contest - RoiEvenHaim's results

gas optimization

object++ cost more then ++object .

The default value of uint is 0. So there is no need to set false at index variable. uint256 index = 0 cost more then uint256 index.

The default value of bool is false. So there is no need to set false at assigned variable. bool assigned = false cost more then bool assigned.

BathPair.sol

line 310 -
bool assigned = false;

fix -
bool assigned;

line 311- 
for (uint256 index = 0; index < array.length; index++) {
            if (uid == array[index]) {
                _index = index;
                assigned = true;
                return _index;
            }
        }

fix -
for (uint256 index; index < array.length; ++index) {
            if (uid == array[index]) {
                _index = index;
                assigned = true;
                return _index;
            }
        }

line 427- 
for (uint256 index = 0; index < quantity; index++) {
            placeMarketMakingTrades(
                tokenPair,
                askNumerators[index],
                askDenominators[index],
                bidNumerators[index],
                bidDenominators[index]
            );
        }

fix- 
for (uint256 index; index < quantity; ++index) {
            placeMarketMakingTrades(
                tokenPair,
                askNumerators[index],
                askDenominators[index],
                bidNumerators[index],
                bidDenominators[index]
            );
        }

line 480- 
for (uint256 index = 0; index < quantity; index++) {
            requote(
                ids[index],
                tokenPair,
                askNumerators[index],
                askDenominators[index],
                bidNumerators[index],
                bidDenominators[index]
            );
        }

fix- 
for (uint256 index; index < quantity; ++index) {
            requote(
                ids[index],
                tokenPair,
                askNumerators[index],
                askDenominators[index],
                bidNumerators[index],
                bidDenominators[index]
            );
        }

line 582 -
for (uint256 index = 0; index < ids.length; index++) {
            uint256 _id = ids[index];
            scrubStrategistTrade(_id);
        }

fix -
for (uint256 index = 0; index < ids.length; index++) {
            uint256 _id = ids[index];
            scrubStrategistTrade(_id);
        }

line 206 -
last_stratTrade_id++;

fix -
++last_stratTrade_id;

line 277- 
current[target] = current[current.length - 1];

fix- 
current[target] = current[--current.length];

BathToken.sol

line 635 - 
for (uint256 index = 0; index < bonusTokens.length; index++) {
                IERC20 token = IERC20(bonusTokens[index]);
                // Note: Shares already burned in Bath Token _withdraw

                // Pair each bonus token with a lightly adapted OZ Vesting wallet. Each time a user withdraws, they
                //  are released their relative share of this pool, of vested BathBuddy rewards
                // The BathBuddy pool should accrue ERC-20 rewards just like OZ VestingWallet and simply just release the withdrawer's relative share of releaseable() tokens
                if (rewardsVestingWallet != IBathBuddy(0)) {
                    rewardsVestingWallet.release(
                        (token),
                        receiver,
                        sharesWithdrawn,
                        initialTotalSupply,
                        feeBPS
                    );
                }
            }
        }

fix - 
for (uint256 index; index < bonusTokens.length; ++index) {
                IERC20 token = IERC20(bonusTokens[index]);
                // Note: Shares already burned in Bath Token _withdraw

                // Pair each bonus token with a lightly adapted OZ Vesting wallet. Each time a user withdraws, they
                //  are released their relative share of this pool, of vested BathBuddy rewards
                // The BathBuddy pool should accrue ERC-20 rewards just like OZ VestingWallet and simply just release the withdrawer's relative share of releaseable() tokens
                if (rewardsVestingWallet != IBathBuddy(0)) {
                    rewardsVestingWallet.release(
                        (token),
                        receiver,
                        sharesWithdrawn,
                        initialTotalSupply,
                        feeBPS
                    );
                }
            }
        }

line 733-
nonces[owner]++

fix-
++nonces[owner]

RubiconMarket.sol

line 436 -
last_offer_id++;

fix -
++last_offer_id;

line 1165-
_span[address(pay_gem)][address(buy_gem)]++;

fix-
_span[address(pay_gem)][address(buy_gem)]++;

line 990 -
uint256 old_top = 0;

fix -
uint256 old_top;

RubiconRouter.sol

line 85 -
for (uint256 index = 0; index < topNOrders; index++) {
            if (index == 0) {
                lastAsk = bestAskID;
                lastBid = bestBidID;

fix -
for (uint256 index; index < topNOrders; ++index) {
            if (index == 0) {
                lastAsk = bestAskID;
                lastBid = bestBidID;

line 165 - 
for (uint256 i = 0; i < route.length - 1; i++) {
            (address input, address output) = (route[i], route[i + 1]);
            uint256 _pay = i == 0

fix - 
for (uint256 i; i < route.length - 1; ++i) {
            (address input, address output) = (route[i], route[i + 1]);
            uint256 _pay = i == 0

line 227 -
for (uint256 i = 0; i < route.length - 1; i++) {
            (address input, address output) = (route[i], route[i + 1]);
            uint256 _pay = i == 0

fix -
for (uint256 i; i < route.length - 1; ++i) {
            (address input, address output) = (route[i], route[i + 1]);
            uint256 _pay = i == 0

line 82 -
uint256 lastBid = 0;

fix -
uint256 lastBid;

line 83 - 
uint256 lastAsk = 0;

fix - 
uint256 lastAsk;

line 168 - 
uint256 currentAmount = 0;

fix - 
uint256 currentAmount;

line 226 - 
uint256 currentAmount = 0;

fix - 
uint256 currentAmount;