Using function parameters in emits saves gas

[code423n4]

Handle

0xRajeev

Vulnerability details

Impact

Public/external setter functions that emit events to indicate the newly set values can use the function parameters (from memory/calldata) or their cached versions as emit arguments instead of the state variables that were just written to because SLOADs cost 2100/100 gas depending on cold/warm reads from Berlin upgrade onwards.

Proof of Concept

https://github.com/sushiswap/miso/blob/2cdb1486a55ded55c81898b7be8811cb68cfda9e/contracts/Liquidity/PostAuctionLauncher.sol#L160

Tools Used

Manual Analysis

Recommended Mitigation Steps

Use function parameters or cached local variables in emits to save gas.