[jesse__]

EDIT: I forgot to mention that for tight performance, avoid branches. This means ifs, switchs, loops, goto, etc. Sometimes you need branches, but mispredicted branches can be extremely costly, causing pipeline stalls and flushes. This is why using a static loop is important; so the compiler can unroll it and not use a branch.

I also should mention that I hate flamegraphs. They only give you a bare minimum amount of information for doing performance work. I'm not sure of a good JS profiler, but what you want to be able to do is mark up the sections of code you want profiled, instead of the profiler taking random samples and squashing them all together. Look at the tracy profiler for an example