jit

问题 I always come across articles which claim that Java is interpreted. I know that Oracle's HotSpot JRE provides just-in-time compilation, however is this the case for a majority of desktop users? For example, if I download Java via: http://www.java.com/en/download, will this include a JIT Compiler? 回答1: Yes, absolutely. Articles claiming Java is interpreted are typically written by people who either don't understand how Java works or don't understand what interpreted means. Having said that,

问题 Suppose we have 3 methods: method 2 is called from method 1, method 3 is called from method 2. Methods 2 and 3 are of size 30 bytecodes each. Also, suppose for definiteness method 2 is always called from method 1 exactly once, and method 3 is always called from method 2 exaclty once. If method 2 is inlined first, method 3 will be called from the body of method 1 directly, and could be inlined in its turn. If method 3 is inlined into method 2 first, the size of the latter will become about 60

问题 Is it better to use NGEN an ASP.NET application when we know it is not going to change much? Or is the JIT good enough? The only reason I asked was because this article by Jeffrey Richter in 2002 says : And, of course, Microsoft is working quite hard at improving the CLR and its JIT compiler so that it runs faster, produces more optimized code, and uses memory more efficiently. These improvements will take time. For developers that can't wait, the .NET Framework redistributable includes a

问题 Let's say the bottleneck of my Java program really is some tight loops to compute a bunch of vector dot products. Yes I've profiled, yes it's the bottleneck, yes it's significant, yes that's just how the algorithm is, yes I've run Proguard to optimize the byte code, etc. The work is, essentially, dot products. As in, I have two float[50] and I need to compute the sum of pairwise products. I know processor instruction sets exist to perform these kind of operations quickly and in bulk, like SSE

问题 I am trying to optimize my simulator by leveraging run-time compilation. My code is pretty long and complex, but I identified a specific __device__ function whose performances can be strongly improved by removing all global memory accesses. Does CUDA allow the dynamic compilation and linking of a single __device__ function (not a __global__ ), in order to "override" an existing function? 回答1: I am pretty sure the really short answer is no. Although CUDA has dynamic/JIT device linker support,

问题 Why is the JIT-compiler not working for the following code? And every individual loop seem to take too long time (see my other post about executing time. Speed of simple loop public static void main (String[] args) { for (int j = 0; j < 10; j++) { float f; long start = System.nanoTime(); for (int i = 0; i < 2000000000; i++) { f = i * 0.0001F; } long end = System.nanoTime(); long timeToCallNanoTime = System.nanoTime() - end; long time = Math.max(0, end - start - timeToCallNanoTime); System.out

问题 I was reading about the advantages of JIT over precompiled and one of those mentioned was that a JIT could adjust branch predictions based on actual runtime data. Now it's been a long time since I wrote a compiler in college, but it seems to me that something similar can be achieved for precompiled code also in most cases (where there are no explicit gotos). Consider the following code: test x jne L2: L1: ... jmp L3: L2: ... L3: If we have some runtime instrumentation that sees how many times

问题 i was following the Performance Tips through the developer site. There mentions about android devices that don't have a JIT. But i searched for jit-less devices but could not find a broad list. There are also huge differences between devices with and without a JIT: the best code for a device with a JIT is not always the best code for a device without. or On devices without a JIT, it is true that invoking methods via a variable with an exact type rather than an interface is slightly more

问题 I am trying to replace a method in a plugin loader(Like Bukkit for Minecraft) during run-time. I cannot modify the assembly file directly in this instance. The whole purpose is to be able to tell when the methods are being called. And cancel them if necessary. Once my plugin is loaded I run the following code: public static void PluginLoaded() { replace(); } public static void replace() { MethodInfo oldMethod, newMethod; oldMethod = typeof(<other assembly>).GetMethod("<method name>",

问题 Receiving this error message: Failed at nopython (nopython frontend) [1m[1m[1mInvalid usage of Function(<function argsort at 0x0000000002A67840>) with parameters (array(float64, 2d, C), axis=int64) * parameterized In definition 0: While using this code def rankbids(bids, shifts, groupPeriod, period): rowsSize = bids.shape[0]; finaltable = np.zeros((rowsSize, groupPeriod), dtype=np.float64) for i in range(0, period): #for 0 to 99 #CONSTANT 4 UPDATE WHEN NEEDED for worker in range(rowsSize):