In CUDA, you can create a kernel at runtime, compile it into PTX and load it then and there. How can I do the same thing in C++ AMP?
No. There is no way to do this with C++ AMP. It might be possible using the underlying DirectCompute APIs, rather than the C++AMP ones.
I'd be interested to know what problem you are trying to solve that needs kernel generation at runtime.
Related
I've been trying to write Vulkan bindings for a language and I'm a bit confused about how extensions work. On Linux I'm using libdl to load function pointers from libvulkan.so.1, and I've noticed that some extension functions (like those from VK_KHR_swapchain and VK_KHR_Wayland_Surface) can be linked through libdl, but others (like the ones in VK_EXT_debug_utils or VK_EXT_extended_dynamic_state2) can only be found through vkGetInstanceProcAddr or vkGetDeviceProcAddr.
My questions are these:
Why are some Vulkan extensions available through dynamic linking but not others?
Can I rely on these dynamically-linkable extensions always being there? (For example, can I be sure that if the VK_KHR_swapchain extension is available, vkCreateSwapchainKHR will definitly be found by libdl?)
TFM:
Vulkan Direct Exports
The loader library on Windows, Linux, Android, and macOS will export all core Vulkan entry-points and all appropriate Window System Interface (WSI) entry-points. This is done to make it simpler to get started with Vulkan development. When an application links directly to the loader library in this way, the Vulkan calls are simple trampoline functions that jump to the appropriate dispatch table entry for the object they are given.
Specifics: https://github.com/KhronosGroup/Vulkan-Loader/blob/main/docs/LoaderApplicationInterface.md#wsi-extensions
There are lots of oop languages, but I couldn't find any that has conveniences like garbage collection, but compiles natively to machine code. Sort of like between C and java/c#. One interesting language I found was Vala, but that's limited to the GNOME platform and is not that well-known
Go is probably closest.
But why on earth do you want it natively compiled anyway?
JIT compilation of portable bytecode has proved to be an extremely effective strategy. It compiles down to native code at runtime (so you get up to the performance of native code after the first few iterations) and it avoids the issues of having to build and manage platform-specific compiled binaries.
Are you thinking about C++? That is in high usage and can be compiled on nearly any (major) platform.
In the case you want to use an oo language that compiles down to native code you will "always" have to use header files and stuff as the elf format doesn't support oo (There is no class information in elf).In case you want to use classes from external libs you need to make the compiler aware somehow about the fact that there are classes, functions, etc. that are declared outside of your project. In C++ this is solved by the use of header files. So that's, I think, a major drawback in native object oriented languages. To resolve that issue a few tweaks would need to be made to elf/loader/linker in order to support the kind of features (like "linking" against "classes") you might expect. Even though mechanism for garbage collection could be implemented even in native languages. But that seems no good for os implementation.
There are C++ libs to do that for userspace apps like:
Boehm collector
Smart pointers
Suppose I have a software and I want to make cross-plataform plugins. You compile the plugin for a virtual machine, and any platform running my software would be able to run this code.
I am wondering if it is possible to use LLVM interpreter and bytecode for this purpose. Also, I am wondering if does make sense using LLVM for this purpose instead of something else, i.e. is it what LLVM was made for?
I'm not sure that LLVM was designed for it. However, I doubt there is anything that hasn't been done using LLVM1
Other virtual-machines based script engines are specifically created for the job:
LUA is very popular
Wikipedia lists some other Extension/embeddable languages under the Scripting language entry
If you're looking for embeddable virtual machines:
IKVM supports embedding JVM and CLR in a bridged mode (interoperable)
Parrot supports embedding (and includes a Python interpreter; mind you, you can just run python bytecode images)
Perl has similar architecture and supports embedding
Javascript supports embedding (not sure about the architecture of v8, but I guess it would use a virtual machine)
Mono's CLR engine supports embedding: http://www.mono-project.com/Embedding_Mono
1 including compiling c++ information to javascript to run in your browser...
There is VMIR (https://github.com/andoma/vmir) which is a LLVM bitcode interpreter / JIT engine that's intended to be embedded into other apps.
Disclaimer: I'm the author of it and it's still work-in-progress but works reasonable well.
In theory, there exist a limited subset of LLVM IR which can be portable across various platforms. You shall not specify alignments, you shall not bitcast pointers to integral types, you must avoid intrinsics, etc. Which means - you can't immediately use a code generated by a stock C compiler (llvm-gcc, Clang, whatever), unless you specify a limited target for it and implement sanitising LLVM passes. Another issue is that the bitcode format from different LLVM versions is not guaranteed to be compatible.
In practice, I would not go there. Mono is a reasonably small, embeddable, fast VM, and all the .NET stack of tools is available for it. VM itself is pretty low-level (as long as you do not care about the verifyability).
LLVM includes an interpreter, so if you can build this interpreter for your target platforms, you can then evaluate LLVM bitcode on the fly.
It's apparently not so fast though.
In their classic discussion (that you do not want to miss if you're a fan of open source, LLVM, compilers) about LLVM vs libJIT, that has happened long before LLVM became famous and established, the author of libJIT Rhys Weatherley raised this particular issue, he stated that LLVM is not suitable to be embedded, while Chris Lattner, the author of LLVM stated that otherwise, it is modular and you can use it in any possible fashion including embedding only the parts you need.
I want to create an Objective-C application which lets you specify a class implementation at runtime.
I want the user to type some code (correctness of the code is out of scope for now).
When the user is done i want to create a class of the typed code and use it in the application.
So i want to dynamically add code in runtime of the application. Is this possible?
If so, how can i achieve this? If not, why not and are there any alternatives to create the same effect which i want to create?
Thanks.
You can dynamically load classes at runtime, but to get there you'd first need to handle distributing a compiler, its compilation dependencies (headers, ...), setup its enviroment, etc.
Usually applications use scripting languages that are painlessly embeddable (Lua, Python, ...) or already available on the platform (JavaScript, AppleScript, ...).
I'd check out F-Script. It's closer to smalltalk than Obj-C, but IMO it's closer to Obj-C than JavaScript or Lua :-)
On iOS devices, this isn't possible. On a Mac you could link against the clang+llvm libraries and use them to generate code into a buffer, then mprotect() the buffer to be executable, I believe.
I would like to know how I can import a library into Objective-C at runtime. I'm new to Objective-C and this may be a complex question, but I'm fairly proficient in C/C++,
I'm developing a modular application where specific modules (libraries) are loaded as needed. Basically I have a name in runtime, like "nodeX", and I want to load a library that has it.
I've been searching for a way to do this but have been unsuccessful.
Thanks!
See NSBundle.
Note that you can't safely unload code on Mac OS X, Objective-C or otherwise, unless you are so terribly careful that it just isn't worth the effort to do so.
Note, also, that you can't dynamically load code on iOS.