jit

I try to optimize the performance of a node.js application and therefore I am analyzing the behavior of V8's JIT compiler. When running the application via node --trace_deopt --trace_opt --code_comments --print_optcode ... , the output contains many recurring lines like the following: [didn't find optimized code in optimized code map for 0x490a8b4aa69 <SharedFunctionInfo>] How can I find out which javascript code corresponds to 0x490a8b4aa69 ? The full output is available here . TylerY86 That error message used to be around line 10200 of v8/src/objects.cc , but is no more. It basically means

Does CUDA support JIT compilation of a CUDA kernel? I know that OpenCL offers this feature. I have some variables which are not changed during runtime (i.e. only depend on the input file), therefore I would like to define these values with a macro at kernel compile time (i.e at runtime). If I define these values manually at compile time my register usage drops from 53 to 46, what greatly improves performance. If it is feasible for you to use Python, you can use the excellent pycuda module to compile your kernels at runtime. Combined with a templating engine such as Mako , you will have a very

Interpreters do a lot of extra work, so it is understandable that they end up significantly slower than native machine code. But languages such as C# or Java have JIT compilers, which supposedly compile to platform native machine code. And yet, according to benchmarks that seem legit enough, in most of the cases are still 2-4x times slower than C/C++? Of course, I mean compared to equally optimized C/C++ code. I am well aware of the optimization benefits of JIT compilation and their ability to produce code that is faster than poorly optimized C+C++. And after all that noise about how good the

I am trying to understand how I can configure the type of JIT I want to use. Say, I am aware that there are 3 types of JIT (Pre, Econo and Normal). But have the following curious questions. What is the default JIT with which .NET runs in deployment server? Do we have the flexibility to change the settings to use either pre or econo if the default is normal. If so where I can change this? Not sure, if this setting is in machine.config or something? I never heard of "Econo jit" before. I do see google links, they all point to old articles that talk about .NET 1.x. The "econo" part seems to be

In 2012, a JEP 145 has been created in order to cache compiled native code in java for faster jvm startups . At that time, it had been officially announced. However, the JEP 145 does not exist anymore. What happened to it? The idea sounds great. I could not find an official statement why and when this project has been cancelled. The text of the JEP is still available in the JEP source repository : http://hg.openjdk.java.net/jep/jeps/raw-file/c915dfb4117d/jep-145.md There doesn't seem to be a documented reason for it to be canceled. But we now know that AOT is in the works and it solves many of

Lets compare two pieces of code: String str = null; //Possibly do something... str = "Test"; Console.WriteLine(str); and String str; //Possibly do something... str = "Test"; Console.WriteLine(str); I was always thinking that these pieces of code are equal. But after I have build these code (Release mode with optimization checked) and compared IL methods generated I have noticed that there are two more IL instructions in the first sample: 1st sample code IL: .maxstack 1 .locals init ([0] string str) IL_0000: ldnull IL_0001: stloc.0 IL_0002: ldstr "Test" IL_0007: stloc.0 IL_0008: ldloc.0 IL_0009

I'm trying to know whether creating a Class Data Sharing archive (by running java -Xshare:dump ) compiles byte code into native code. There is not a lot of documentation about the internals of Class Data Sharing. The page I linked says that java -Xshare:dump loads a set of classes from the system jar file into a private internal representation, and dumps that representation to a file. But says nothing about whether this code is compiled or not. (Possibly related: Speed up application start by adding own application classes to classes.jsa ) In both cases it's native code in the cache (see the

I'm working on an application where I'd like to dynamically generate code for a numerical calculation (for performance). Doing this calculation as a data driven operation is too slow. To describe my requirements, consider this class: class Simulation { Dictionary<string, double> nodes; double t, dt; private void ProcessOneSample() { t += dt; // Expensive operation that computes the state of nodes at the current t. } public void Process(int N, IDictionary<string, double[]> Input, IDictionary<string, double[]> Output) { for (int i = 0; i < N; ++i) { foreach (KeyValuePair<string, double[]> j in