Platform: Code4rena
Start Date: 03/05/2022
Pot Size: $50,000 USDC
Total HM: 4
Participants: 46
Period: 5 days
Judge: gzeon
Total Solo HM: 2
Id: 117
League: ETH
Rank: 46/46
Findings: 1
Award: $47.56
🌟 Selected for report: 0
🚀 Solo Findings: 0
🌟 Selected for report: BowTiedWardens
Also found by: 0v3rf10w, 0x1f8b, 0x4non, 0xDjango, 0xNazgul, 0xkatana, Cityscape, Fitraldys, Funen, GimelSec, IllIllI, MaratCerby, Picodes, TerrierLover, Tomio, delfin454000, ellahi, fatherOfBlocks, hansfriese, ilan, joestakey, oyc_109, rfa, robee, samruna, simon135, slywaters, throttle
47.5594 USDC - $47.56
> 0 is less efficient than != 0 for unsigned integers
it may seem that > 0 is cheaper than !=, this is only true without the optimizer enabled and outside a require statement. If you enable the optimizer at 10k AND you’re in a require statement, this will save gas.
soruce : https://twitter.com/gzeon/status/1485428085885640706
POC : https://github.com/bunkerfinance/bunker-protocol/blob/752126094691e7457d08fc62a6a5006df59bd2fe/contracts/Oracles/UniswapV2PriceOracle.sol#L67 https://github.com/bunkerfinance/bunker-protocol/blob/752126094691e7457d08fc62a6a5006df59bd2fe/contracts/Oracles/UniswapV2PriceOracle.sol#L91 https://github.com/bunkerfinance/bunker-protocol/blob/752126094691e7457d08fc62a6a5006df59bd2fe/contracts/Oracles/UniswapV2PriceOracle.sol#L115