feat(protocol): reduce gas cost by skipping reading storage for `dele…

…gates()` (#17487)

Co-authored-by: Daniel Wang <[email protected]>

packages/protocol/contracts/tko/TaikoToken.sol

@@ -11,9 +11,13 @@ import "./TaikoTokenBase.sol";
 /// 0x10dea67478c5F8C5E2D90e5E9B26dBe60c54d800 (token.taiko.eth)
 /// @custom:security-contact [email protected]
 contract TaikoToken is TaikoTokenBase {
+    address private constant _TAIKO_L1 = 0x06a9Ab27c7e2255df1815E6CC0168d7755Feb19a;
+    address private constant _ERC20_VAULT = 0x996282cA11E5DEb6B5D122CC3B9A1FcAAD4415Ab;
+
     /// @notice Initializes the contract.
     /// @param _owner The owner of this contract. msg.sender will be used if this value is zero.
     /// @param _recipient The address to receive initial token minting.
+
     function init(address _owner, address _recipient) public initializer {
         __Essential_init(_owner);
         __ERC20_init("Taiko Token", "TKO");
@@ -22,4 +26,10 @@ contract TaikoToken is TaikoTokenBase {
         // Mint 1 billion tokens
         _mint(_recipient, 1_000_000_000 ether);
     }
+
+    function delegates(address account) public view virtual override returns (address) {
+        // Special checks to avoid reading from storage slots
+        if (account == _TAIKO_L1 || account == _ERC20_VAULT) return address(0);
+        else return super.delegates(account);
+    }
 }