Gas Optimizations

[code423n4]

G001 ++I COSTS LESS GAS COMPARED TO I++ OR I += 1 (SAME FOR --I VS I-- OR I -= 1)

Pre-increments and pre-decrements are cheaper.

For a uint256 i variable, the following is true with the Optimizer enabled at 10k:

Increment:

• i += 1 is the most expensive form
• i++ costs 6 gas less than i += 1
• ++i costs 5 gas less than i++ (11 gas less than i += 1)

Decrement:

• i -= 1 is the most expensive form
• i-- costs 11 gas less than i -= 1
• --i costs 5 gas less than i-- (16 gas less than i -= 1)

https://github.com/code-423n4/2022-08-olympus/blob/b5e139d732eb4c07102f149fb9426d356af617aa/src/policies/Operator.sol#L488

decimals++;

G002 - Cache Array Length Outside of Loop

Description

Caching the array length outside a loop saves reading it on each iteration, as long as the array's length is not changed during the loop.

https://github.com/code-423n4/2022-08-olympus/blob/b5e139d732eb4c07102f149fb9426d356af617aa/src/policies/Governance.sol#L278

for (uint256 step; step < instructions.length; ) {

Background info

code-423n4/2021-11-badgerzaps-findings#36