> This thread might be relevant: > > https://lkml.org/lkml/2015/2/2/600 > > and perhaps using fls might still be a good approach.
Linus wrote: >>> We *probably* have some argument range that we care more about, which is why I'd like to know what the profile is that triggered this optimization, and what the common argument range is. <<< That's exactly what I did. Used perf probe to get the common range and optimize for that. -Andi