This slide deck has a nice example of using a comment to fix a performance bug in a js implementation of the chacha20 cipher: http://mrale.ph/talks/goto2015/#/1

This slide deck has a nice example of using a comment to fix a performance bug in a js implementation of the chacha20 cipher: http://mrale.ph/talks/goto2015/#/14 http://mrale.ph/talks/goto2015/#/14