Gas Optimizations

[code423n4]

general considerations

• there are multiple instances of block.timestamp.safeCastTo32(), which could be changed to uint32(block.timestamp) with no practical risk, and saves the require() check
• uint256 should be used in many scenarios inside of the functions or as function parameters instead, and only cast it into a lower size uint, when storing it instead. reference. for example timestamp is being casted way too early, and then being used, resulting in higher gas.
• snapshots below were run with forge snapshot --optimize --optimize-runs 1000000

use storage pointers where possible [ERC20MultiVotes]

diff --git a/.gas-snapshot b/.gas-snapshot
index c5e3f62..c439cf6 100644
--- a/.gas-snapshot
+++ b/.gas-snapshot
@@ -53,13 +53,13 @@ ERC20MultiVotesTest:testCanContractExceedMax() (gas: 35031)
 ERC20MultiVotesTest:testCanContractExceedMaxNonContractFails() (gas: 13535)
 ERC20MultiVotesTest:testCanContractExceedMaxNonOwnerFails() (gas: 13760)
 ERC20MultiVotesTest:testDecrementOverWeightFails() (gas: 247398)
-ERC20MultiVotesTest:testDecrementUntilFreeDouble() (gas: 350624)
-ERC20MultiVotesTest:testDecrementUntilFreeSingle() (gas: 327524)
+ERC20MultiVotesTest:testDecrementUntilFreeDouble() (gas: 350352)
+ERC20MultiVotesTest:testDecrementUntilFreeSingle() (gas: 327354)
 ERC20MultiVotesTest:testDecrementUntilFreeWhenFree() (gas: 375129)
 ERC20MultiVotesTest:testDelegateOverMaxDelegatesApproved() (gas: 509277)
 ERC20MultiVotesTest:testDelegateOverMaxDelegatesFails() (gas: 413581)
 ERC20MultiVotesTest:testDelegateOverVotesFails() (gas: 247599)
 ERC20MultiVotesTest:testDelegateToAddressZeroFails() (gas: 87370)
-ERC20MultiVotesTest:testPastVotes() (gas: 351022)
+ERC20MultiVotesTest:testPastVotes() (gas: 350952)
 ERC20MultiVotesTest:testSetMaxDelegatesNonOwnerFails() (gas: 13647)
-ERC20MultiVotesTest:testUndelegate() (gas: 211796)
+ERC20MultiVotesTest:testUndelegate() (gas: 211684)
diff --git a/src/token/ERC20MultiVotes.sol b/src/token/ERC20MultiVotes.sol
index 08e2242..bb75374 100644
--- a/src/token/ERC20MultiVotes.sol
+++ b/src/token/ERC20MultiVotes.sol
@@ -260,13 +260,14 @@ abstract contract ERC20MultiVotes is ERC20, Auth {
         address delegatee,
         uint256 amount
     ) internal virtual {
-        uint256 newDelegates = _delegatesVotesCount[delegator][delegatee] - amount;
+        mapping(address => uint256) storage ptr = _delegatesVotesCount[delegator];
+        uint256 newDelegates = ptr[delegatee] - amount;
 
         if (newDelegates == 0) {
             require(_delegates[delegator].remove(delegatee));
         }
 
-        _delegatesVotesCount[delegator][delegatee] = newDelegates;
+        ptr[delegatee] = newDelegates;
         userDelegatedVotes[delegator] -= amount;
 
         emit Undelegation(delegator, delegatee, amount);
@@ -339,19 +340,22 @@ abstract contract ERC20MultiVotes is ERC20, Auth {
         uint256 totalFreed;
 
         // Loop through all delegates
-        address[] memory delegateList = _delegates[user].values();
+        EnumerableSet.AddressSet storage _delegatesUser = _delegates[user];
+        address[] memory delegateList = _delegatesUser.values();
 
         // Free delegates until through entire list or under votes amount
         uint256 size = delegateList.length;
         for (uint256 i = 0; i < size && (userFreeVotes + totalFreed) < votes; i++) {
             address delegatee = delegateList[i];
-            uint256 delegateVotes = _delegatesVotesCount[user][delegatee];
+
+            mapping(address => uint256) storage _delegatesVotesCountUser = _delegatesVotesCount[user];
+            uint256 delegateVotes = _delegatesVotesCountUser[delegatee];
             if (delegateVotes != 0) {
                 totalFreed += delegateVotes;
 
-                require(_delegates[user].remove(delegatee)); // Remove from set. Should never fail.
+                require(_delegatesUser.remove(delegatee)); // Remove from set. Should never fail.
 
-                _delegatesVotesCount[user][delegatee] = 0;
+                _delegatesVotesCountUser[delegatee] = 0;
 
                 _writeCheckpoint(delegatee, _subtract, delegateVotes);
                 emit Undelegation(user, delegatee, delegateVotes);

use storage pointers where possible [ERC20Gauges]

diff --git a/.gas-snapshot b/.gas-snapshot
index c439cf6..ddddaf1 100644
--- a/.gas-snapshot
+++ b/.gas-snapshot
@@ -4,17 +4,17 @@ FlywheelTest:testAccrueTwoUsersSeparately() (gas: 330979)
 FlywheelTest:testFailAddStrategy() (gas: 15092)
 FlywheelTest:testSetFlywheelBoosterUnauthorized() (gas: 13594)
 FlywheelTest:testSetFlywheelRewardsUnauthorized() (gas: 13615)
-FlywheelGaugeRewardsTest:testGetPriorRewards() (gas: 566359)
-FlywheelGaugeRewardsTest:testGetRewards() (gas: 546077)
+FlywheelGaugeRewardsTest:testGetPriorRewards() (gas: 566122)
+FlywheelGaugeRewardsTest:testGetRewards() (gas: 545907)
 FlywheelGaugeRewardsTest:testGetRewardsUninitialized() (gas: 12512)
-FlywheelGaugeRewardsTest:testIncompletePagination() (gas: 972359)
-FlywheelGaugeRewardsTest:testPagination() (gas: 900730)
-FlywheelGaugeRewardsTest:testQueue() (gas: 524891)
-FlywheelGaugeRewardsTest:testQueueFullPagination() (gas: 527970)
-FlywheelGaugeRewardsTest:testQueueSkipCycle() (gas: 345785)
-FlywheelGaugeRewardsTest:testQueueSkipCycleFullPagination() (gas: 348443)
-FlywheelGaugeRewardsTest:testQueueTwoCycles() (gas: 560780)
-FlywheelGaugeRewardsTest:testQueueTwoCyclesFullPagination() (gas: 566759)
+FlywheelGaugeRewardsTest:testIncompletePagination() (gas: 972019)
+FlywheelGaugeRewardsTest:testPagination() (gas: 900390)
+FlywheelGaugeRewardsTest:testQueue() (gas: 524721)
+FlywheelGaugeRewardsTest:testQueueFullPagination() (gas: 527800)
+FlywheelGaugeRewardsTest:testQueueSkipCycle() (gas: 345700)
+FlywheelGaugeRewardsTest:testQueueSkipCycleFullPagination() (gas: 348358)
+FlywheelGaugeRewardsTest:testQueueTwoCycles() (gas: 560543)
+FlywheelGaugeRewardsTest:testQueueTwoCyclesFullPagination() (gas: 566522)
 FlywheelGaugeRewardsTest:testQueueWithoutGaugesBeforeCycle() (gas: 13468)
 FlywheelGaugeRewardsTest:testQueueWithoutGaugesNoGauges() (gas: 69137)
 FlywheelStaticRewardsTest:testGetAccruedRewards() (gas: 97429)
@@ -23,27 +23,27 @@ FlywheelStaticRewardsTest:testGetAccruedRewardsCappedAfterEnd() (gas: 97873)
 FlywheelStaticRewardsTest:testSetRewardsInfo() (gas: 39879)
 ERC20GaugesTest:testAddGaugeNonOwner() (gas: 38452)
 ERC20GaugesTest:testAddGaugeTwice() (gas: 113090)
-ERC20GaugesTest:testCalculateGaugeAllocation() (gas: 488805)
+ERC20GaugesTest:testCalculateGaugeAllocation() (gas: 488640)
 ERC20GaugesTest:testCanContractExceedMax() (gas: 35078)
 ERC20GaugesTest:testCanContractExceedMaxNonContract() (gas: 13603)
 ERC20GaugesTest:testCanContractExceedMaxNonOwner() (gas: 13917)
-ERC20GaugesTest:testDecrement() (gas: 310594)
-ERC20GaugesTest:testDecrementAllRemovesGauge() (gas: 300684)
-ERC20GaugesTest:testDecrementGauges() (gas: 432470)
-ERC20GaugesTest:testDecrementGaugesOver() (gas: 415437)
-ERC20GaugesTest:testDecrementGaugesSizeMismatch() (gas: 466673)
-ERC20GaugesTest:testDecrementUntilFreeDeprecated() (gas: 447041)
-ERC20GaugesTest:testDecrementUntilFreeDouble() (gas: 431097)
-ERC20GaugesTest:testDecrementUntilFreeSingle() (gas: 449392)
-ERC20GaugesTest:testDecrementUntilFreeWhenFree() (gas: 477079)
-ERC20GaugesTest:testDecrementWithStorage() (gas: 324403)
-ERC20GaugesTest:testIncrementAtMax() (gas: 380777)
-ERC20GaugesTest:testIncrementGauges() (gas: 477454)
+ERC20GaugesTest:testDecrement() (gas: 310419)
+ERC20GaugesTest:testDecrementAllRemovesGauge() (gas: 300562)
+ERC20GaugesTest:testDecrementGauges() (gas: 432171)
+ERC20GaugesTest:testDecrementGaugesOver() (gas: 415206)
+ERC20GaugesTest:testDecrementGaugesSizeMismatch() (gas: 466503)
+ERC20GaugesTest:testDecrementUntilFreeDeprecated() (gas: 446756)
+ERC20GaugesTest:testDecrementUntilFreeDouble() (gas: 430812)
+ERC20GaugesTest:testDecrementUntilFreeSingle() (gas: 449178)
+ERC20GaugesTest:testDecrementUntilFreeWhenFree() (gas: 476909)
+ERC20GaugesTest:testDecrementWithStorage() (gas: 324228)
+ERC20GaugesTest:testIncrementAtMax() (gas: 380697)
+ERC20GaugesTest:testIncrementGauges() (gas: 477289)
 ERC20GaugesTest:testIncrementGaugesDeprecated() (gas: 282189)
-ERC20GaugesTest:testIncrementGaugesOver() (gas: 421785)
+ERC20GaugesTest:testIncrementGaugesOver() (gas: 421615)
 ERC20GaugesTest:testIncrementGaugesSizeMismatch() (gas: 281154)
-ERC20GaugesTest:testIncrementOverMax() (gas: 420342)
-ERC20GaugesTest:testIncrementWithStorage() (gas: 514952)
+ERC20GaugesTest:testIncrementOverMax() (gas: 420170)
+ERC20GaugesTest:testIncrementWithStorage() (gas: 514787)
 ERC20GaugesTest:testRemoveGauge() (gas: 179755)
 ERC20GaugesTest:testRemoveGaugeNonOwner() (gas: 112716)
 ERC20GaugesTest:testRemoveGaugeTwice() (gas: 180455)
diff --git a/src/token/ERC20Gauges.sol b/src/token/ERC20Gauges.sol
index ad8fabe..2b59338 100644
--- a/src/token/ERC20Gauges.sol
+++ b/src/token/ERC20Gauges.sol
@@ -259,9 +259,10 @@ abstract contract ERC20Gauges is ERC20, Auth {
             if (cycle - block.timestamp <= incrementFreezeWindow) revert IncrementFreezeError();
         }
 
-        bool added = _userGauges[user].add(gauge); // idempotent add
-        if (added && _userGauges[user].length() > maxGauges && !canContractExceedMaxGauges[user])
-            revert MaxGaugeError();
+        EnumerableSet.AddressSet storage pUserGauges = _userGauges[user];
+
+        bool added = pUserGauges.add(gauge); // idempotent add
+        if (added && pUserGauges.length() > maxGauges && !canContractExceedMaxGauges[user]) revert MaxGaugeError();
 
         getUserGaugeWeight[user][gauge] += weight;
 
@@ -337,9 +338,10 @@ abstract contract ERC20Gauges is ERC20, Auth {
         uint112 weight,
         uint32 cycle
     ) internal {
-        uint112 oldWeight = getUserGaugeWeight[user][gauge];
+        mapping(address => uint112) storage pUserGaugeWeight = getUserGaugeWeight[user];
+        uint112 oldWeight = pUserGaugeWeight[gauge];
 
-        getUserGaugeWeight[user][gauge] = oldWeight - weight;
+        pUserGaugeWeight[gauge] = oldWeight - weight;
         if (oldWeight == weight) {
             // If removing all weight, remove gauge from user list.
             require(_userGauges[user].remove(gauge));
@@ -561,9 +563,11 @@ abstract contract ERC20Gauges is ERC20, Auth {
 
         // Free gauges until through entire list or under weight
         uint256 size = gaugeList.length;
+        mapping(address => uint112) storage pUserGaugeWeight = getUserGaugeWeight[user];
+
         for (uint256 i = 0; i < size && (userFreeWeight + totalFreed) < weight; ) {
             address gauge = gaugeList[i];
-            uint112 userGaugeWeight = getUserGaugeWeight[user][gauge];
+            uint112 userGaugeWeight = pUserGaugeWeight[gauge];
             if (userGaugeWeight != 0) {
                 // If the gauge is live (not deprecated), include its weight in the total to remove
                 if (!_deprecatedGauges.contains(gauge)) {

unchecked i++ [FlywheelGaugeRewards]

diff --git a/.gas-snapshot b/.gas-snapshot
index ddddaf1..14733f7 100644
--- a/.gas-snapshot
+++ b/.gas-snapshot
@@ -4,17 +4,17 @@ FlywheelTest:testAccrueTwoUsersSeparately() (gas: 330979)
 FlywheelTest:testFailAddStrategy() (gas: 15092)
 FlywheelTest:testSetFlywheelBoosterUnauthorized() (gas: 13594)
 FlywheelTest:testSetFlywheelRewardsUnauthorized() (gas: 13615)
-FlywheelGaugeRewardsTest:testGetPriorRewards() (gas: 566122)
-FlywheelGaugeRewardsTest:testGetRewards() (gas: 545907)
+FlywheelGaugeRewardsTest:testGetPriorRewards() (gas: 565862)
+FlywheelGaugeRewardsTest:testGetRewards() (gas: 545777)
 FlywheelGaugeRewardsTest:testGetRewardsUninitialized() (gas: 12512)
-FlywheelGaugeRewardsTest:testIncompletePagination() (gas: 972019)
-FlywheelGaugeRewardsTest:testPagination() (gas: 900390)
-FlywheelGaugeRewardsTest:testQueue() (gas: 524721)
-FlywheelGaugeRewardsTest:testQueueFullPagination() (gas: 527800)
-FlywheelGaugeRewardsTest:testQueueSkipCycle() (gas: 345700)
-FlywheelGaugeRewardsTest:testQueueSkipCycleFullPagination() (gas: 348358)
-FlywheelGaugeRewardsTest:testQueueTwoCycles() (gas: 560543)
-FlywheelGaugeRewardsTest:testQueueTwoCyclesFullPagination() (gas: 566522)
+FlywheelGaugeRewardsTest:testIncompletePagination() (gas: 971499)
+FlywheelGaugeRewardsTest:testPagination() (gas: 900130)
+FlywheelGaugeRewardsTest:testQueue() (gas: 524591)
+FlywheelGaugeRewardsTest:testQueueFullPagination() (gas: 527670)
+FlywheelGaugeRewardsTest:testQueueSkipCycle() (gas: 345635)
+FlywheelGaugeRewardsTest:testQueueSkipCycleFullPagination() (gas: 348293)
+FlywheelGaugeRewardsTest:testQueueTwoCycles() (gas: 560283)
+FlywheelGaugeRewardsTest:testQueueTwoCyclesFullPagination() (gas: 566262)
 FlywheelGaugeRewardsTest:testQueueWithoutGaugesBeforeCycle() (gas: 13468)
 FlywheelGaugeRewardsTest:testQueueWithoutGaugesNoGauges() (gas: 69137)
 FlywheelStaticRewardsTest:testGetAccruedRewards() (gas: 97429)
diff --git a/src/rewards/FlywheelGaugeRewards.sol b/src/rewards/FlywheelGaugeRewards.sol
index 85a77c0..f099b07 100644
--- a/src/rewards/FlywheelGaugeRewards.sol
+++ b/src/rewards/FlywheelGaugeRewards.sol
@@ -186,7 +186,7 @@ contract FlywheelGaugeRewards is Auth, BaseFlywheelRewards {
 
         if (size == 0) revert EmptyGaugesError();
 
-        for (uint256 i = 0; i < size; i++) {
+        for (uint256 i = 0; i < size; ) {
             ERC20 gauge = ERC20(gauges[i]);
 
             QueuedRewards memory queuedRewards = gaugeQueuedRewards[gauge];
@@ -206,6 +206,10 @@ contract FlywheelGaugeRewards is Auth, BaseFlywheelRewards {
             });
 
             emit QueueRewards(address(gauge), currentCycle, nextRewards);
+
+            unchecked {
+                i++;
+            }
         }
     }