My understanding is that the optimizations haven't been implemented yet in the VM, but that this initial step is to enable the new bytecodes. Could be wrong.
The idea in sista is to do all fancy optimizations in the image by translating bytecodes to different bytecodes. The VM (called Cog, in this case) just has to translate the bytecodes to native binaries on demand.
This requires new bytecodes, like unchecked fast primitive calls, so that sista can have Cog generate better binaries.
This requires new bytecodes, like unchecked fast primitive calls, so that sista can have Cog generate better binaries.