RyuJIT and .NET 4.6
It’s been a while since we’ve posted here, and a lot has happened with RyuJIT since the last post.
First and foremost, RyuJIT is the default x64 JIT for .NET 4.6! As a result, there is no need to use a RyuJIT CTP to try out RyuJIT. If you install the .NET 4.6 Preview (included in Visual Studio 2015 Preview), or later build, such as Visual Studio 2015 RC, you will be using it. See here or the .NET blog for more details.
One thing we need to point out, though: if you have previously configured your machine to use a RyuJIT CTP (using the instruction here), and you update to .NET 4.6, you need to make sure the COMPLUS_AltJit environment variable and the HKLM\SOFTWARE\Microsoft\.NETFramework\AltJit registry value do not exist. If they do exist, every .NET application will fail to run. You don’t want that!
Update: the specific failure you will get is exception number -2146233082 (in hex: 0x80131506), otherwise known as COR_E_EXECUTIONENGINE or "Internal CLR error". This will be the process exit code. For console applications, you can see this by examining %ERRORLEVEL% after the process terminates (if you are working in a CMD.EXE window). You may also see a dialog box stating "<application> has stopped working", and if you expand "View problem details", you will see "Fault Module Name: clr.dll" and "Exception Code: 80131506". You will also see an entry in the Event Viewer, Application log, source ".NET Runtime", listing this error code. Note that there are other reasons this exception number could be generated; a stray AltJit configuration is not the only reason for this exception.
Note that this information has also been published as KB3065367 here.
Secondly, RyuJIT is now open source! See here for details.
We hope you enjoy the benefits of all the work we’ve put into RyuJIT. If you have any feedback on RyuJIT, send us mail at firstname.lastname@example.org. We want to hear from you!