The benchmark uses the JavaScript for-in loop to iterate through object keys. My advisor convinced me that I should address this performance problem, and to do that, I had to make for-in loops faster. Higgs (old for-in) >500s Higgs (new for-in) 2.91s V8 3.29.66 (baseline) 4.98s V8 3.29.66 (Crankshaft) 4.95s TraceMonkey 4.12s