Gas Optimizations #172

code423n4 · 2022-07-02T18:55:46Z

[G-01] ++i costs less gas than i++, especially when it's used in for loops (same for ++j vs j++)

[G-02] Use nested multiple require instead of && operator
Require statements including conditions with the && operator can be broken down in multiple require statements to save gas.

Mitigation:
Breakdown each condition in a separate require statement (though require statements should be replaced with custom errors).

[G-03] Use nested multiple if instead of && operator
If statements including conditions with the && operator can be broken down in multiple if statements to save gas.

[G-04] custom errors
Custom errors from Solidity 0.8.4 are cheaper than revert strings (cheaper deployment cost and runtime cost when the revert condition is met) while providing the same amount of information, as explained here
https://blog.soliditylang.org/2021/04/21/custom-errors/
Custom errors are defined using the error statement

Instances include:
https://github.com/Plex-Engineer/lending-market-v2/blob/443a8c0fed3c5018e95f3881a31b81a555c42b2d/contracts/Stableswap/BaseV1-core.sol#L275
https://github.com/Plex-Engineer/lending-market-v2/blob/443a8c0fed3c5018e95f3881a31b81a555c42b2d/contracts/Stableswap/BaseV1-core.sol#L291
https://github.com/Plex-Engineer/lending-market-v2/blob/443a8c0fed3c5018e95f3881a31b81a555c42b2d/contracts/Governance/GovernorBravoDelegate.sol#L25
https://github.com/Plex-Engineer/lending-market-v2/blob/443a8c0fed3c5018e95f3881a31b81a555c42b2d/contracts/Governance/GovernorBravoDelegate.sol#L26
https://github.com/Plex-Engineer/lending-market-v2/blob/443a8c0fed3c5018e95f3881a31b81a555c42b2d/contracts/Governance/GovernorBravoDelegate.sol#L27

Mitigation:
Replace require statements with custom errors.

[G-05] Comparison operators
In the EVM, there is no opcode for >= or <=. When using greater than or equal, two operations are performed: > and =.
Using strict comparison operators hence saves gas.

Mitigation:
Replace <= with <, and >= with >. Do not forget to increment/decrement the compared variable.

[G-06] Reduce the size of error messages (Long revert Strings)
Shortening revert strings to fit in 32 bytes will decrease deployment time gas and will decrease runtime gas when the revert condition is met.
Revert strings that are longer than 32 bytes require at least one additional mstore, along with additional overhead for computing memory offset, etc.

Mitigation:
I suggest shortening the revert strings to fit in 32 bytes

[G-07] public functions not called by the contract should be declared external instead
https://github.com/Plex-Engineer/lending-market-v2/blob/443a8c0fed3c5018e95f3881a31b81a555c42b2d/contracts/Accountant/AccountantInterfaces.sol#L37
https://github.com/Plex-Engineer/lending-market-v2/blob/443a8c0fed3c5018e95f3881a31b81a555c42b2d/contracts/Treasury/TreasuryDelegate.sol#L19
https://github.com/Plex-Engineer/lending-market-v2/blob/443a8c0fed3c5018e95f3881a31b81a555c42b2d/contracts/Treasury/TreasuryInterfaces.sol#L25

GalloDaSballo · 2022-08-14T20:49:30Z

Less than 100 gas saved

code423n4 added bug Something isn't working G (Gas Optimization) labels Jul 2, 2022

code423n4 added a commit that referenced this issue Jul 2, 2022

JC issue #172

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Gas Optimizations #172

Gas Optimizations #172

code423n4 commented Jul 2, 2022

GalloDaSballo commented Aug 14, 2022

Gas Optimizations #172

Gas Optimizations #172

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code423n4 commented Jul 2, 2022

GalloDaSballo commented Aug 14, 2022