Foundation Drop contest - medikko's results

Intializing the variables to zero that aren't constant or immutable will cost more gas rather than use default value of zero.

If you not overwritte the default value you will save 8 gas for stack variables and more for storage and memory variables.

There are 8 instances of this issue:

File: /contracts/PercentSplitETH.sol:

115: for (uint256 i = 0; i < _shares.length; ++i) {

135: for (uint256 i = 0; i < shares.length; ++i) {

320: for (uint256 i = 0; i < shares.length; ++i) {

File: /contracts/libraries/BytesLibrary.sol

25:     for (uint256 i = 0; i < 20; ++i) {

44:     for (uint256 i = 0; i < 4; ++i) {

File: /contracts/mixins/shared/MarketFees.sol

126:    for (uint256 i = 0; i < creatorRecipients.length; ++i) {

198:    for (uint256 i = 0; i < creatorShares.length; ++i) {

484:    for (uint256 i = 0; i < creatorRecipients.length; ++i) {

Use of ++i/i++ should be unchecked{++i}/unchecked{i++}in for-loops

Not using a unchecked{++i}/unchecked{i++} will cost more gas because the default compiler overflow and underflow safety checks. This is true from version 0.8.0, code below match that requirments.

There are 2 instances of this issue:

File: /contracts/PercentSplitETH.sol:

115: for (uint256 i = 0; i < _shares.length; ++i) {

320: for (uint256 i = 0; i < shares.length; ++i) {

If you use bit shifting will save some gas

Use of bit shifting operations are more cheap than normal multiplication/division operations.

There are 3 instances of this issue:

File: /contracts/FETH.sol

210:    lockupInterval = _lockupDuration / 24;

211:    if (lockupInterval * 24 != _lockupDuration || _lockupDuration == 0) {

File: ./contracts/libraries/LockedBalance.sol

100: uint256 lockupMetadata = lockups.lockups[index / 2];