4 ms·

Interesting. What is that thing exactly? Is there a bug we can follow?

• bzbarsky 9y ago
  Actually, I guess there are two things: 1) If you have a class definition inside a function, that function doesn't get jitted. The functions in the class definition itself can still get jitted. 2) Class methods that use super don't get jitted at the moment. So if your class definitions are not in the same function as your hot code and don't use super, you get fast paths. Otherwise some things will run in the interpreter. The tracking bug for this is https://bugzilla.mozilla.org/show_bug.cgi?id=1167472 https://bugzilla.mozilla.org/show_bug.cgi?id=1167472 and https://bugzilla.mozilla.org/show_bug.cgi?id=1167472#c13 https://bugzilla.mozilla.org/show_bug.cgi?id=1167472#c13 is what the above summary is based on.