CODEWITHSUNDEEP
cuda
Sneha
Sneha

Reputation: 7

how to use my existing .cpp code with cuda

I hv code in c++ and wanted to use it along with cuda.Can anyone please help me? Should I provide my code?? Actually I tried doing so but I need some starting code to proceed for my code.I know how to do simple square program (using cuda and c++)for windows(visual studio) .Is it sufficient to do the things for my program?

Upvotes: 0

Views: 6659

Answers (3)

Ade Miller
Ade Miller

Reputation: 13743

The following are both good places to start. CUDA by Example is a good tutorial that gets you up and running pretty fast. Programming Massively Parallel Processors includes more background, e.g. chapters on the history of GPU architecture, and generally more depth.

CUDA by Example: An Introduction to General-Purpose GPU Programming

Programming Massively Parallel Processors: A Hands-on Approach

These both talk about CUDA 3.x so you'll want to look at the new features in CUDA 4.x at some point.

Thrust is definitely worth a look if your problem maps onto it well (see comment above). It's an STL-like library of containers, iterators and algorithms that implements data-parallel algorithms on top of CUDA.

Here are two tutorials on getting started with CUDA and Visual C++ 2010:

http://www.ademiller.com/blogs/tech/2011/03/using-cuda-and-thrust-with-visual-studio-2010/

http://blog.cuvilib.com/2011/02/24/how-to-run-cuda-in-visual-studio-2010/

There's also a post on the NVIDIA forum:

http://forums.nvidia.com/index.php?showtopic=184539

Asking very general how do I get started on ... on Stack Overflow generally isn't the best approach. Typically the best reply you'll get is "go read a book or the manual". It's much better to ask specific questions here. Please don't create duplicate questions, it isn't helpful.

Upvotes: 7

phimuemue
phimuemue

Reputation: 36071

It's a non-trivial task to convert a program from straight C(++) to CUDA. As far as I know, it is possible to use C++ like stuff within CUDA (esp. with the announced CUDA 4.0), but I think it's easier to start with only C stuff (i.e. structs, pointers, elementary data types).

Start by reading the CUDA programming guide and by examining the examples coming with the CUDA SDK or available here. I personally found the vector addition sample quite enlightening. It can be found over here.

I can not tell you how to write your globals and shareds for your specific program, but after reading the introductory material, you will have at least a vague idea of how to do.

The problem is that it is (as far as I know) not possible to tell a generic way of transforming pure C(++) into code suitable for CUDA. But here are some corner stones for you:

  • Central idea for CUDA: Loops can be transformed into different threads executed multiple times in parallel on the GPU.
  • Therefore, the single iterations optimally are independent of other iterations.
  • For optimal execution, the single execution branches of the threads should be (almost) the same, i.e. the single threads sould do almost the same.

Upvotes: 4

CygnusX1
CygnusX1

Reputation: 21818

You can have multiple .cpp and .cu files in your project. Unless you want your .cu files to contain only device code, it should be fairly easy.

For your .cu files you specify a header file, containing host functions in it. Then, include that header file in other .cu or .cpp files. The linker will do the rest. It is nothing different than having multiple plain C++ .cpp files in your project.

I assume you already have CUDA rule files for your Visual Studio.

Upvotes: 2

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