davidmarkclements
commented
6 years ago can you please post benchmark before/after results in this thread?
instanceof is notoriously slow in the Turbofan V8 – if we can't do this in a fast way I'd rather not do it
if we do merge, then we'll also want to put it into quick-format-unescaped branch which is used 200x more than quick-format - so it's 200 times more important that this change doesn't hinder performance
cover case which arg is an instance of Error