Gas: Avoid expensive calculation by checking if `valueAll() == 0`

[code423n4]

Handle

Dravee

Vulnerability details

Impact

Checking if the value is 0 before returning 0 is less expensive than returning a calculation that's equal to 0

Proof of Concept

In Vault.sol:underlyingValue(), the code is as follows:

Vault.sol
400:     function underlyingValue(address _target)
401:         public
402:         view
403:         override
404:         returns (uint256)
405:     {
406:         if (attributions[_target] > 0) {
407:             return (valueAll() * attributions[_target]) / totalAttributions;
408:         } else {
409:             return 0;
410:         }
411:     }

It can be optimized as such:

406:         uint256 valueAll = valueAll();
407:         if (valueAll != 0 && attributions[_target] > 0) {
408:             return (valueAll * attributions[_target]) / totalAttributions;
409:         } else {
410:             return 0;
411:         }

Tools Used

VS Code

Recommended Mitigation Steps

Cache the loaded storage value in a memory variable and make the 0 checks to avoid unnecessary calculations if valueAll() == 0

[oishun1112]

https://github.com/code-423n4/2022-01-insure-findings/issues/343 implement with this together