Application that uses CUDA DLL

Accelerated Computing CUDA CUDA Programming and Performance
1

Hi everybody!

I have created a CUDA .dll file in Visual Studio 2010. I have the .lib file also.
Now I’m trying to call a function contained the .dll file from another code (the application code).

My application code is the following, it is very simple:

#include “stdafx.h”
#include <cuda_runtime_api.h>

__declspec(dllimport) void ForwardPropagation();

int _tmain(int argc, _TCHAR* argv)
{

printf("Calling main... \n");
ForwardPropagation();
printf("\nDONE! \n");

return 0;

}

When I try to compile it, it appears the following error in the output section in VS 2010:

1>cuda_vector_app.obj : error LNK2019: unresolved external symbol “__declspec(dllimport) void __cdecl ForwardPropagation(void)” (_imp?ForwardPropagation@@YAXXZ) referenced in function wmain
1>C:\Users\Student3\Documents\cuda_vector_app_3\x64\Debug\cuda_vector_app.exe : fatal error LNK1120: 1 unresolved externals

I’m not sure why this error is appearing because I have implemented another code under the same premises and I don’t have problems with it. I don’t know why for this specific case the compilation presents this error.

All comments and suggestions will be appreciated.

Arturo V.

2

Are you trying to use static or dynamic loading? (Have you put the .lib in the “input” field of the linked for compilation?)
Are you exposing a header file associated with the library that would have function signatures?

From what you have shown, I see no way for the linker to know how and where ForwardPropagation is implemented.

In a general way, there is nothing different between a “regular” DLL and a CUDA DLL, so if you know how to work with one, you know how to work with the other.

3

I think it is a static loading. I specified the path of my .lib file before compilation.

I changed ‘ForwardPropagation’ by ‘main’ in my application and in my DLL and everything went OK… every time I execute the .exe of the application, the DLL is invoked. I’m not sure why this change made the difference.

What do you think?