Fraxlend (Frax Finance) contest - Ruhum's results

Gas Report

• G-01: use constant
• G-02: use immutable
• G-03: use unchecked when incrementing a loop's iterator
• G-04: use ++i

G-01: use constant

• https://github.com/code-423n4/2022-08-frax/blob/main/src/contracts/FraxlendPairDeployer.sol#L49-L51

G-02: use immutable

• https://github.com/code-423n4/2022-08-frax/blob/main/src/contracts/FraxlendPairDeployer.sol#L57-L59

G-03: use unchecked when incrementing a loop's iterator

Realistically the iterator can't overflow because of the loop's condition. Incrementing it within an unchecked block will save gas.

for (uint i; i < length;) {
    unchecked {
        ++i;
    }
}

./src/contracts/FraxlendPair.sol:289:        for (uint256 i = 0; i < _lenders.length; i++) {
./src/contracts/FraxlendPair.sol:308:        for (uint256 i = 0; i < _borrowers.length; i++) {
./src/contracts/libraries/SafeERC20.sol:27:            for (i = 0; i < 32 && data[i] != 0; i++) {
./src/contracts/FraxlendWhitelist.sol:53:        for (uint256 i = 0; i < _addresses.length; i++) {
./src/contracts/FraxlendWhitelist.sol:68:        for (uint256 i = 0; i < _addresses.length; i++) {
./src/contracts/FraxlendWhitelist.sol:83:        for (uint256 i = 0; i < _addresses.length; i++) {
./src/contracts/FraxlendPairCore.sol:265:        for (uint256 i = 0; i < _approvedBorrowers.length; ++i) {
./src/contracts/FraxlendPairCore.sol:270:        for (uint256 i = 0; i < _approvedLenders.length; ++i) {

G-04: use ++i

++i is cheaper than i++ when incrementing a loop's iterator.

./src/contracts/FraxlendPairDeployer.sol:131:                i++;
./src/contracts/FraxlendPairDeployer.sol:159:                i++;
./src/contracts/FraxlendPair.sol:289:        for (uint256 i = 0; i < _lenders.length; i++) {
./src/contracts/FraxlendPair.sol:308:        for (uint256 i = 0; i < _borrowers.length; i++) {
./src/contracts/libraries/SafeERC20.sol:24:                i++;
./src/contracts/libraries/SafeERC20.sol:27:            for (i = 0; i < 32 && data[i] != 0; i++) {
./src/contracts/FraxlendWhitelist.sol:53:        for (uint256 i = 0; i < _addresses.length; i++) {
./src/contracts/FraxlendWhitelist.sol:68:        for (uint256 i = 0; i < _addresses.length; i++) {