Yieldy contest - sach1r0's results

Gas Optimization

!= is cheaper in gas compared to > for uint

Details

!= 0 costs less gas compared to > 0 for unsigned integers in require statements with the optimizer enabled (6 gas) see reference: https://github.com/code-423n4/2021-12-maple-findings/issues/75

Mitigation

use != 0 instead of > 0

Line of code

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L118 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L410 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L572 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L604 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Yieldy.sol#L83

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Functions that are only called externally must set its visibility to external instead of public

Details

Setting function's visibility to external when it is only called externally can save gas because external function’s parameters are not copied into memory and are instead read from calldata directly. see reference: https://github.com/code-423n4/2021-06-gro-findings/issues/37

Mitigation

set function visibility to external

Line of code

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L370 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Yieldy.sol#L138 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Yieldy.sol#L205 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Yieldy.sol#L227

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No need to explicitly initialize variables with their default values

Details

When variables are not set, it is assumed to have it's default value(0 for uint, 0 for int, false for bool, address(0) for address). Explicitly initializing it with its default value is an anti-pattern and wastes gas.

Mitigation

change int128 from = 0; to int128 from; see reference: https://code4rena.com/reports/2022-02-jpyc/ [G-07] GENERAL RECOMMENDATIONS

Line of code

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L636-L637