Compiling Ruby and Python interpreters with Clang? - clang

I'm just curious; are there any benchmarks about how compiling interpreters for dynamic languages with Clang affects the performance of these languages? Do those interpreters even compile?

http://sayspy.blogspot.com/2009/08/compiling-python-using-clang.html
I'd love to see this done in windows.

Ruby 1.9.2-rc2 successfully compiled
http://joneslee85.wordpress.com/2010/04/23/howto-compile-ruby-1-9-2-head-with-clang-svn-head-on-mac-os-x-10-6-3/

Here's a blog entry Compiling Python using Clang. Sounds like little or no improvement in speed. Better diagnostics and faster compile though.

Related

What is the difference between Emscripten and Clang in terms of WebAssembly compilation

I know both clang (by use target=wasm32) and emscripten can compile C code into webassembly, but how are they different?
It looks like they both use LLVM as backend. Actually, I do not even quite understand the relation between llvm and clang...
I have been reading WebAssembly for a while, but I lack low-level understanding of it. Thank you so much for your time!!
clang is a compiler built on llvm technology so you often hear clang and llvm used interchangeably. clang is a just one component of the llvm project.
emscripten is a compiler that uses clang for most of the heavy lifting of actually compiling to WebAssembly but also add a lot of features and functionality on top of that, mostly related to seamless integration with JavaScript and the web and emulation of POSIX and other standards.
emscripten runs clang internally with --target=wasm32-unknown-emscripten which has some very minor differences to the regular --target=wasm32.
If you run emscripten with -v it will print the full clang command line its uses under the hood.

I am using Mac, can I install visual C++ 2015 redistribution? because after that I want to install opencv3

Well, I am going to do some deep learning stuff with opencv.
I have already installed scikit-image and scikit-learn.
No, but you could install some C++ compiler on MacOSX.
Visual C++ is a C++ compiler and IDE for Windows (don't confuse it with Visual Studio Code, which is a cross-platform IDE). You need some compiler for MacOSX, which is a Unix variant and nearly POSIX (it could be certified to some specific POSIX standard, but I don't know which).
Probably, both GCC and Clang are available on MacOSX (see this). You need to find some packaged version of them, perhaps with brew; both compilers work really well. Apple is partly funding Clang. GCC is funded by many other corporations. They both are open source compilers, but with a different license (GCC is mostly GPLv3+). GCC is probably producing some faster code (when optimizing, faster by a few percents only). Clang is probably giving better diagnostics. I actually recommend installing both of them (and using occasionally both of them too).
Take care to install recent versions of GCC & Clang. Both are very active projects, and are progressing quite well.
You probably need to install other things too. E.g. a build automation tool (like GNU make), a version control system (like git), a source code editor (like emacs or vim).
You might even install some fancy IDE like Clion, Code::Blocks, XCode, etc.. I recommend avoiding that, because you need to learn how to compile on the command line. These fancy tools are running the command line compiler under the hoods, and you really need to understand what they are doing (and hiding from you). Actually C and C++ are somehow not IDE friendly (you really need to understand what the compiler is doing). In both C11 specification (n1570) and in C++11 specification (n3337) the notion of translation unit and of preprocessing is important (and sadly, IDEs tend to hide these notions).
As remarked in comments, you could install the XCode package (which pulls useful packages like GCC or Clang, etc...), but avoid using the XCode IDE.

Implementing a programming language on the GraalVM architecture

What are the (architectural) differences in implementing a programming language on the GraalVM architecture – in particular between Graal, Truffle, and LLVM using Sulong?
I plan to reimplement an existing statically typed programming language on the GraalVM architecture, so that I can use it from Java without much of a hassle.
There are at moment three options:
Emit JVM bytecode
Write a Truffle interpreter
Emit LLVM bitcode, use Sulong to run it on GraalVM
Emitting JVM bytecode is the traditional option. You will have to work at the bytecode level, and you'll have to optimise your code your before emitting bytecode as the options that the JVM has for optimising it after it has been emitted are limited. To get good performance you may have to use invokedynamic.
Using Truffle is I'd say the easy option. You only have to write an AST interpreter and then code generation is all done for you. It's also the high performance option - in all languages where there is a Truffle version and a bytecode version, the Truffle version confidently outperforms the bytecode version as well as being simpler due to no bytecode generation stage.
Emitting LLVM bitcode and running on Sulong is an option, but it's not one I would recommend unless you have other constraints that lead you towards that option. Again you have to do that bitcode generation yourself, and you'll have to optimise yourself before emitting the bitcode as optimisations are limited after the bitcode is set.
Ruby is good for comparing these options - because there is a version that emits JVM bytecode (JRuby), a version using Truffle (TruffleRuby) and a version that emits LLVM bitcode (Rubinius, but it doesn't then run that bitcode on Sulong). I'd say that TruffleRuby is both faster and simpler in implementation than Rubinius or JRuby. (I work on TruffleRuby.)
I wouldn't worry about the fact that your language is statically typed. Truffle can work with static types, and it can use profiling specialisation to detect more fine-grained types again at runtime than are expressed statically.

Could someone please explain the differences between Graal, GraalVM, Truffle & SubstrateVM?

I know these technologies are all related but could someone please explain what each one is used for and how they fit together?
Oversimplification:
Graal - Java bytecode compiler. Can be used just in time (as part of a JVM) or ahead of time.
SubstrateVM - other things (runtime) needed to actually run ahead-of-time compiled Java bytecode without a JVM. This powers the "native-image" command of GraalVM.
Truffle - framework for implementing languages as AST interpreters which can be just-in-time compiled using graal. Some notable languages implemented are JavaScript, Ruby, R and LLVM bitcode.
GraalVM - most of these technologies packaged together in order to support different use cases, for example: running JVM programs (i.e. anything that compiles to Java bytecode) using Graal as the JIT compiler for better peak performance, ahead-of-time compiling JVM programs for fast startup and low memory footprint, running fast dynamic languages (JS, R, Ruby) that can interoperate without overhead, and so on.

Which IDE in order to install and use a compiler with C++14 constexpr relaxation?

I apologize if this question is out of topic, but it's a matter of accessibility for C++14 programmers.
Today i've updated Qt v5.4 on my PC (Windows 8.1/64bit/x86) and it support now the gcc compiler v4.9.2. But i've seen that constexpr relaxation (which really interest me) is available since gcc v5.1.
A search on google shows that :
clang is the better compiler for C++14 latest features (v3.6 is even dealing with experimental C++17)
clang is not easily suitable with Qt libraries
both gcc and clang "datas" are downloadable but i'm not an expert...
So i'm asking how to get a free IDE on Windows 8.1 with an adequate compiler.
If i dismiss Qt for my C++14 experiments, is Codeblocks a better solution ?
Does any else IDE already include an adequate compiler during the installation ?
Where can i find help to install such a compiler ?
Your question is poorly phrased -- for the most part, ide's and compilers are decoupled -- the exception that comes to mind is visual studio, which is an ide that is tightly coupled to microsoft's compiler.
Whether you chose codeblocks, or eclipse, or use a simple text editor, you should be able to choose your compiler fairly easily, and independently of your ide. So you have two independent questions: Where can you get a free compiler for windows with high standards compliance, and what's a good IDE with which to use that compiler.
I'm not a windows person, but very simple, one-file projects, you might actually find it easy to use a gnu-linux environment, which you can do under windows by using cygwin:
http://preshing.com/20141108/how-to-install-the-latest-gcc-on-windows/
This may seem daunting at first, but let me tell you the benefits:
you'll learn the difference between your compiler and editor.
As long as you are only experimenting with the standard, you may find it simpler to get set up than using an ide.
You'll have to learn about the c++ compile process (compiling, linking, possibly preprocessing), not about ide specific stuff.
This will prevent you from conflating ide-specific stuff with c++ stuff, as you have done in your question. As you begin working with projects you'll probably find an ide an advantage, but in the beginning staying close to the raw tools may give you the fastest learning return on investment.
After install cygwin, all you have to do is write your code (using a syntax highlighting editor like gedit or emacs is suggested), and then run
g++ -std=c++14 filename.cpp
to compile your code.
You should be able to use clang under cygwin as well.

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