Math Code Style Findings

MHT-01C: Ineffectual Usage of Safe Arithmetics

Type	Severity	Location
Language Specific		Math.sol:L47, L51, L78, L154, L162

Description:

The linked mathematical operation is guaranteed to be performed safely by surrounding conditionals evaluated in either require checks or if-else constructs.

Example:

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70function invFloor(uint256 x) internal pure returns (uint256) {
71    unchecked {
72        return 1e36 / x;
73    }
74}
75
76function invCeil(uint256 x) internal pure returns (uint256 result) {
77    result = invFloor(x);
78    if (mulmod(ONE, ONE, x) != 0) result = result + 1;
79}

Recommendation:

Given that safe arithmetics are toggled on by default in pragma versions of 0.8.X, we advise the linked statement to be wrapped in an unchecked code block thereby optimizing its execution cost.

Alleviation (175f8c39b19df69134add3aa8a2a042ce3047763):

All referenced arithmetic statements have been wrapped in an unchecked code block as advised, optimizing their gas cost.

MHT-02C: Potentially Confusing Terminology

Type	Severity	Location
Code Style		Math.sol:L158, L169

Description:

The Math::toScale and Math::fromScale functions are slightly contradictory in their terminology, as the Math::toScale function will convert an amount to its input scaleFactor from the "main" 1e18 scale while the Math::fromScale function will convert an amount to the "main" 1e18 scale from its input scaleFactor.

Example:

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158function toScale(uint256 amount, uint256 scaleFactor, bool ceil) internal pure returns (uint256 z) {
159    if (scaleFactor == DEFAULT_SCALE || amount == 0) {
160        return amount;
161    } else {
162        if (!ceil) return amount / scaleFactor;
163        assembly ("memory-safe") {
164            z := add(div(sub(amount, 1), scaleFactor), 1)
165        }
166    }
167}
168
169function fromScale(uint256 amount, uint256 scaleFactor) internal pure returns (uint256) {
170    if (scaleFactor == DEFAULT_SCALE) {
171        return amount;
172    } else {
173        return amount * scaleFactor;
174    }
175}

Recommendation:

As both the scale of the token and the scale of the system are "scales", we advise the functions to utilize different terminology (i.e. normalize, denormalize) that better illustrates their purpose.

As the scale of the system (1e18) represents a "one-to-many" relation between the scales of each token, the Math::fromScale function should be considered to convert from the singular 1e18 project scale to the token's respective scale.

Alleviation (175f8c39b19df69134add3aa8a2a042ce3047763):

The referenced functions have been aptly renamed to indicate the conversion path they implement (i.e. Math::ammScaleToTokenScale and Math::tokenScaleToAmmScale), illustrating their intended usage and addressing the exhibit's concerns as a result.

MHT-03C: Repetitive Value Literal

Type	Severity	Location
Code Style		Math.sol:L72, L143

Description:

The linked value literal is repeated across the codebase multiple times.

Example:

Copy
72return 1e36 / x;

Recommendation:

We advise it to be set to a constant variable instead, optimizing the legibility of the codebase.

In case the constant has already been declared, we advise it to be properly re-used across the code.

Alleviation (175f8c39b19df69134add3aa8a2a042ce3047763):

The referenced value literal 1e36 has been properly relocated to a file-level constant declaration labelled ONE_SQUARED within the Constants file, optimizing the code's legibility.