Microsoft makes new test build available of its 64-bit RyuJIT compiler

Microsoft makes new test build available of its 64-bit RyuJIT compiler

Summary: Microsoft has released a second test build of its new 64-bit RyuJIT.Net compiler.


Microsoft made available on February 27 a second Community Technology Preview (CTP) test build of its RyuJIT compiler.


The goal of the RyuJIT team is to make RyuJIT the "One True .NET JIT Compiler." (JIT stands for just in time.) It will be the basis for all of Microsoft's JIT compilers in the future, the team has said. 

With CTP 2, RyuJIT now provides the equivalent functionality of Microsoft's existing JIT64 compiler. The team says there are now no feature differences at all between the two. Edit and Continue and "opportunistic tail calls" are both now part of RyuJIT as of CTP 2. The new test build also includes performance tweaks and other new features, the team said.

"RyuJIT generates code that’s on average better than the existing JIT64, while it continues to maintain the 2X throughput wins over JIT64," according to a blog post on the new CTP.

During the CTP phase, RyuJIT works only on Windows 8.1 and Windows Server 2012 R2. Once the compiler is final, Microsoft plans to expand the set of supported operating systems. The team isn't providing a taret date as to when that may be.

The CTP 2 installer for RyuJIT can be downloaded here.

RyuJIT takes its name from RyuJin, the mythological Japanese sea deity.

Topics: Software Development, Microsoft, Windows


Mary Jo has covered the tech industry for 30 years for a variety of publications and Web sites, and is a frequent guest on radio, TV and podcasts, speaking about all things Microsoft-related. She is the author of Microsoft 2.0: How Microsoft plans to stay relevant in the post-Gates era (John Wiley & Sons, 2008).

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  • On average better?

    That's not very promising.
    • Impressive

      Reducing the JIT time by half (2X better throughput) without compromising generated code speed on average seems very impressive to me.
      • maybe they wrote it in a normal programming language

        like C++
      • No, it is not.

        i could care less about the JIT delay (web and desktop) because it happens only once per reload.
        Also, since (the current CTP) has a limited compatibility, may be it will be the trend in the future and it sounds like a bad deal.