Something was bothering me a bit with the discussion around sqrt's being
slow. Looks like `Math.hypot` has a performance cost associated with it.
Looking at the Chromium source code:
https://chromium.googlesource.com/v8/v8/+/4.3.21/src/math.js?autodive=0%2F%2F#19
and
https://source.chromium.org/chromium/chromium/src/+/main:v8/src/builtins/math.tq;l=36?q=math&sq=&ss=chromium%2Fchromium%2Fsrc:v8%2Fsrc%2F
it looks like maybe we'd be avoiding the multiple arguments that can be
passed into Math.hypot which is maybe the source of the perf hit.
Also, interestingly in `math.tq` you can see it doing this funky sqrt
calculation: `Float64Sqrt((a / max) * (a / max) + (b / max) * (b / max))
* max` - I think that possibly is trying to avoid some overflow in some
cases with bigger numbers, but also possibly with a perf hit.
[edit]: OK, actually on Firefox, doing sqrt seems slower - but digging
more into this, it looks like doing `** 0.5` instead of `sqrt` is much
faster.
More related articles:
- https://stackoverflow.com/questions/71898044/why-is-math-hypot-so-slow
-
https://stackoverflow.com/questions/3764978/why-hypot-function-is-so-slow
-
https://www.reddit.com/r/javascript/comments/wk3e57/askjs_why_mathsqrt_is_so_slow_in_firefox/
[edit again!] looks like this is being fixed in the latest Chrome!
https://blog.seokho.dev/development/2024/03/18/V8-optimize-MathHypot.html
```
┌─────────┬───────┬─────────┬─────────┬─────────┬────────┐
│ (index) │ Cold │ Slowest │ Fastest │ Average │ Total │
├─────────┼───────┼─────────┼─────────┼─────────┼────────┤
│ old │ 13.39 │ 10.07 │ 9.69 │ 9.98 │ 998.57 │
│ sqrt │ 8.19 │ 6.66 │ 6.61 │ 6.67 │ 667.6 │
│ pow 0.5 │ 1.89 │ 0.28 │ 0.28 │ 0.3 │ 29.79 │
│ new │ 1.64 │ 0.28 │ 0.28 │ 0.29 │ 28.95 │
└─────────┴───────┴─────────┴─────────┴─────────┴────────┘
```
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