ScaleUtils Code Style Findings

SUS-01C: Inefficient Erasure of Upper Bits

Type	Severity	Location
Gas Optimization		ScaleUtils.sol:L75

Description:

The referenced statement is meant to zero out the upper bits of the scale variable's raw representation to acquire its lower 128 bits, however, it does so inefficiently as it performs two bitwise shift operations.

Example:

Copy
75uint256 priceScale = (Scale.unwrap(scale) << 128) >> 128;

Recommendation:

We advise a bitwise mask to be utilized via an AND (&) operation, requiring a single EVM instruction to acquire the desired value.

Alleviation:

The code was updated to utilize a PRICE_SCALE_MASK with a bitwise AND operation as advised, optimizing the code's gas cost whilst increasing the statement's legibility.

SUS-02C: Repetitive Value Literal

Type	Severity	Location
Code Style		ScaleUtils.sol:L25, L75, L76

Description:

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

Example:

Copy
25return Scale.wrap((10 ** feedExponent << 128) | 10 ** priceExponent);

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:

The Euler Finance team evaluated this recommendation and opted to not relocate the value of 10 to a constant declaration as they do not consider it a legibility enhancement.

We concur with this assessment and in view of the overall codebase's style and thus mark this exhibit as invalid.