UniswapV3Adapter Code Style Findings

UVA-01C: Inexplicable Usage of Lower-Accuracy Types

Type	Severity	Location
Gas Optimization		UniswapV3Adapter.sol:L25, L29

Description:

The linked variables use a variable type less than 256-bits which is sub-optimal given that the EVM is built to operate on 256-bit types and any type less than that is artificial by the Solidity compiler using padding and unpadding instructions. Additionally, the variables declared in sequence do not occupy a full storage slot (i.e. the bit sum of period, cardinalityPerMinute, and gasPerCardinality does not exceed 256 bits) thus allowing room for expansion of the bit types.

Example:

Copy
24/// @inheritdoc IUniswapV3Adapter
25uint16 public period;
26/// @inheritdoc IUniswapV3Adapter
27uint8 public cardinalityPerMinute;
28/// @inheritdoc IUniswapV3Adapter
29uint32 public gasPerCardinality = 22_250;

Recommendation:

We advise the period to be expanded to a uint32 data type (thus rendering the casting operation performed in _addOrModifySupportForPair redundant) and the gasPerCardinality type to be set to a uint216 data type thus making use of the full storage slot the three variables occupy.

Alleviation:

The period, gasPerCardinality as well as the newly declared gasCostToSupportPool variables have all had their bit-sizes adjusted to fit within the 256-bit threshold described in the exhibit thus optimizing the codebase.