Gas Optimizations

[code423n4]

Use cached variable value

Impact

The _submitOutOrders() function sets batchLength = _batchedOrders.orders.length, but in the for loop the value "_batchedOrders.orders.length" is used instead of "batchLength". Using the cached variable could save gas.

Proof of Concept

The for loop on line 369 could use the batchLength variable. This approach is used in the similar for loop on line 327.

Recommended Mitigation Steps

Use the cached "batchLength" variable

[harleythedogC4]

My personal judgments:

1. "Use cached variable value". Other reports had their submissions marked as invalid as they recommend using a cached length variable, and this was already acknowledged in the first contest. However, this submission is different, since the length is already cached, and so it definitely makes sense to use the cached length. Valid and small-optimization.

[harleythedogC4]

Now, here is the methodology I used for calculating a score for each gas report. I first assigned each submission to be either small-optimization (1 point), medium-optimization (5 points) or large-optimization (10 points), depending on how useful the optimization is. The score of a gas report is the sum of these points, divided by the maximum number of points achieved by a gas report. This maximum number was 10 points, achieved by #67.

The number of points achieved by this report is 1 points.
Thus the final score of this gas report is (1/10)*100 = 10.