Omniscia Xcaliswap Audit

Base64 Code Style Findings

Base64 Code Style Findings

B46-01C: Sub-Optimal Assembly Block

TypeSeverityLocation
Gas OptimizationBase64.sol:L49, L51, L53, L55

Description:

The Base64 implementation by Brecht Devos utilized in the codebase is outdated and sub-optimal as it utilizes an mstore and shr instruction to store 1 byte (8 bits) instead of using the mstore8 instruction directly.

Example:

contracts/periphery/libraries/Base64.sol
37// run over the input, 3 bytes at a time
38for {
39

40} lt(dataPtr, endPtr) {
41

42} {
43    dataPtr := add(dataPtr, 3)
44

45    // read 3 bytes
46    let input := mload(dataPtr)
47

48    // write 4 characters
49    mstore(resultPtr, shl(248, mload(add(tablePtr, and(shr(18, input), 0x3F)))))
50    resultPtr := add(resultPtr, 1)
51    mstore(resultPtr, shl(248, mload(add(tablePtr, and(shr(12, input), 0x3F)))))
52    resultPtr := add(resultPtr, 1)
53    mstore(resultPtr, shl(248, mload(add(tablePtr, and(shr(6, input), 0x3F)))))
54    resultPtr := add(resultPtr, 1)
55    mstore(resultPtr, shl(248, mload(add(tablePtr, and(input, 0x3F)))))
56    resultPtr := add(resultPtr, 1)
57}

Recommendation:

We advise the statements to be updated according to the latest version of Brecht Devos' Base64 library to ensure the codebase is optimal.

Alleviation:

The Xcaliswap team evaluated this exhibit but opted not to apply any changes for it in the current iteration of the protocol.

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