Frax Ether Liquid Staking contest - JAGADESH's results

[G001] Don't Initialize Variables with Default Value

File: src/DepositContract.sol

76: for (uint height = 0; height < DEPOSIT_CONTRACT_TREE_DEPTH; height++) {
148: for (uint height = 0; height < DEPOSIT_CONTRACT_TREE_DEPTH; height++) {

File: src/OperatorRegistry.sol

63:     for (uint256 i = 0; i < arrayLength; ++i) {
84:     for (uint256 i = 0; i < times; ++i) {
114:    for (uint256 i = 0; i < original_validators.length; ++i) {

File: src/frxETHMinter.sol

63:        withholdRatio = 0; // No ETH is withheld initially
64:        currentWithheldETH = 0;
129:       for (uint256 i = 0; i < numDeposits; ++i) {

[G002] ++i/i++ should be unchecked{++i}/unchecked{i++} when it is not possible for them to overflow, as is the case when used in for- and while-loops

File: src/DepositContract.sol

76:  for (uint height = 0; height < DEPOSIT_CONTRACT_TREE_DEPTH; height++) {
148: for (uint height = 0; height < DEPOSIT_CONTRACT_TREE_DEPTH; height++) {

File: src/OperatorRegistry.sol

63:     for (uint256 i = 0; i < arrayLength; ++i) {
84:     for (uint256 i = 0; i < times; ++i) {
114:    for (uint256 i = 0; i < original_validators.length; ++i) {

File: src/frxETHMinter.sol

129: for (uint256 i = 0; i < numDeposits; ++i) {

[G003] ++i costs less gas than i++, especially when it's used in for-loops (--i/i-- too)

File: src/DepositContract.sol

76: for (uint height = 0; height < DEPOSIT_CONTRACT_TREE_DEPTH; height++) {
148: for (uint height = 0; height < DEPOSIT_CONTRACT_TREE_DEPTH; height++) {

[G004] Gas optimizing through arithmetics

<x> / 2 is the same as <x> >> 1. The DIV opcode costs 5 gas, whereas SHR only costs 3 gas

File: src/DepositContract.sol

88:             size /= 2;
154:            size /= 2;

[G005] Use != 0 instead of > 0 for Unsigned Integer Comparison

!= 0 costs less gas compared to > 0 for unsigned integers in require statements with the optimizer enabled (6 gas) For uints the minimum value would be 0 and never a negative value. Since it cannot be a negative value, then the check > 0 is essentially checking that the value is not equal to 0 therefore >0 can be replaced with !=0 which saves gas.

File: src/frxETHMinter.sol

79:        require(sfrxeth_recieved > 0, 'No sfrxETH was returned');
126:       require(numDeposits > 0, "Not enough ETH in contract");

[G006] Cache Array Length Outside of Loop

File: src/OperatorRegistry.sol

114:    for (uint256 i = 0; i < original_validators.length; ++i) {