My (partial/incomplete/buggy/experimental) Ruby compiler generates awful code, and still by far the biggest performance bottleneck is creation and garbage collection of objects that improving the low level code generation will have only marginal effects on.
E.g. finally adding type tagging for integers (instead of creating objects on the heap) sped up compiling itself by tens of times (taking it from unusually slow to comparable to MRI on that specific task) and there's nothing a low level optimizer will do to figure out transformations like that.
Maybe one day I'll get far enough on fixing the high level issues that it'll be worth even trying to do more complex low level optimizations, but that's a long time away.
My (partial/incomplete/buggy/experimental) Ruby compiler generates awful code, and still by far the biggest performance bottleneck is creation and garbage collection of objects that improving the low level code generation will have only marginal effects on.
E.g. finally adding type tagging for integers (instead of creating objects on the heap) sped up compiling itself by tens of times (taking it from unusually slow to comparable to MRI on that specific task) and there's nothing a low level optimizer will do to figure out transformations like that.
Maybe one day I'll get far enough on fixing the high level issues that it'll be worth even trying to do more complex low level optimizations, but that's a long time away.