CLR .tail prefix is only a hint and not guaranteed. And traditionally it's had a ton of restrictions and limitations and was slow enough that F# stopped emittin

CLR .tail prefix is only a hint and not guaranteed. And traditionally it's had a ton of restrictions and limitations and was slow enough that F# stopped emitting it except when needed. (A lot of code ends up tail call optimizable, even if not recursive or designed that way.) Is rather have the JVM's compressed pointers and escape analysis.