Yes, there certainly are such scenarios. JIT compilation can use runtime profiling to optimize specific cases based on measurement of the characteristics of what the code is actually doing at the moment, and can recompile “hot” code as necessary. That’s not theoretical; Java’s HotSpot actually does this. JITters can optimize for the specific CPU and … Read more
Thank you for the isolated repro program and I can confirm that this is indeed a RyuJIT bug in the optimizer which got exposed due to inlining. I’ve made a fix to the compiler and figuring the roll out details. Not to turn SO into a bug tracker, and for a quicker turnaround: ryujit@microsoft.com.
You could use MethodImplAttribute and specify MethodImplOptions.NoInlining. [MethodImpl(MethodImplOptions.NoInlining)] void YourMethod() { // do something } Note that this still doesn’t guarantee that you can get at the actual calling method as seen in the source code. Your method won’t be inlined, but your method’s caller could be inlined into its own caller, etc etc.
c++/cli can theoretically be used with WPF/Silverlight using the trick of replacing the C# generated from the XAML with a macro definition that can be used inside the main class in a code behind file. I worked out this technique but haven’t had the motivation to take it beyond theory – I’m quite happy mixing … Read more
The JIT is just part of the JVM. Other parts include the bytecode interpreter, the class loading verification and linking mechanisms, and the native code support for stuff like reflection, I/O and so on. In that sense, the JIT doesn’t make the JVM run faster at all. Instead it makes Java code run faster … … Read more
Not sure about linux, but this works on x86/windows. Update: http://codepad.org/sQoF6kR8 #include <stdio.h> #include <windows.h> typedef unsigned char byte; int arg1; int arg2; int res1; typedef void (*pfunc)(void); union funcptr { pfunc x; byte* y; }; int main( void ) { byte* buf = (byte*)VirtualAllocEx( GetCurrentProcess(), 0, 1<<16, MEM_COMMIT, PAGE_EXECUTE_READWRITE ); if( buf==0 ) return … Read more
There is no perl6, and there are many Perl 6 compilers. Perl 6 has a grammar, although it’s written in Perl 6, so as long as you can understand that, it tells you everything you need to know. I just asked Larry this question, since I’m sitting across from him at lunch at the São … Read more
It is a jitter implementation detail, the x86 and x64 jitters have subtly different rules. This is casually documented in blog posts of team members that worked on the jitter but the teams certainly reserve the right to alter the rules. Looks like you already found them. Inlining methods from other assemblies is most certainly … Read more
HotSpot compilation policy is rather complex, especially for Tiered Compilation, which is on by default in Java 8. It’s neither a number of executions, nor a matter of CompileThreshold parameter. The best explanation (apparently, the only reasonable explanation) can be found in HotSpot sources, see advancedThresholdPolicy.hpp. I’ll summarize the main points of this advanced compilation … Read more