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This is fascinating. Is the claim here that the C++ version could have never been as fast as the current Java one or just that people have been optimizing the J

This is fascinating. Is the claim here that the C++ version could have never been as fast as the current Java one or just that people have been optimizing the Java one and getting improvements past the C++ one? Also, it sounds like the old C++ JIT has to be maintained and shipped in the event that the Java-based JIT isn't available at startup, right? If so that makes sense as a stop-gap and it would be more of a tiered JIT, not a port. Tiered JITs are definitely proven, successful technology.

chrisseaton 7y ago
> Is the claim here that the C++ version could have never been as fast as the current Java one The claim is that the work to add new optimisations to the old C++ code is so difficult that people aren't prepared to do it. The Java code is easier to write and debug, enough so that people are managing to add new optimisations that they haven't added to the C++ code. > the old C++ JIT has to be maintained and shipped in the event that the Java-based JIT isn't available at startup Well only until the new Java JIT is mature. The AOT build of the Java JIT can be shipped in the binaries so it's always there. > If so that makes sense as a stop-gap and it would be more of a tiered JIT, not a port. Tiered JITs are definitely proven, successful technology. It's used as a new top-tier yes, replacing the C++ top tier. The C++ JIT is likely to go I think, in the medium-to-long term.