[sjrd]

You could use (the compiled and optimized version of) the implementation we have in Scala.js: https://github.com/scala-js/scala-js/blob/master/library/src... It is significantly faster, especially for arithmetic operations, and dramatically so for division, remainder, as well as `toString()` (up to 100x speedup). It also contains the unsigned variant of operations (for java.lang.Lond.divideUnsigned for instance).

[jvilk]

Oh, nice! I'll take a look at that when I next get the chance. I assumed that Closure's Long library, which is based on GWT's Long implementation, would be well-optimized, and never looked into an alternative.