c++cudacompatibility

Can I call CUDA runtime function from C++ code not compiled by nvcc?


Is there any way I can call CUDA runtime function calls such as

cudaMemcpy(...);

in a .cpp file, compiled with a regular C++ compiler?


Solution

  • EDIT: There was an example here but it's not longer found, but most of the example was copied below.

    The caller C (but could be C++)

    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <cuda.h>
    
    extern void kernel_wrapper(int *a, int *b);
    
    int main(int argc, char *argv[])
    {
       int a = 2;
       int b = 3;
    
       kernel_wrapper(&a, &b);
    
       return 0;
    }
    

    The Callee (CUDA)

    __global__ void kernel(int *a, int *b)
    {
       int tx = threadIdx.x;
    
       switch( tx )
       {
    case 0:
        *a = *a + 10;
        break;
    case 1:
        *b = *b + 3;
        break;
    default:
        break;
       }
    }
    
    void kernel_wrapper(int *a, int *b)
    {
       int *d_1, *d_2;
       dim3 threads( 2, 1 );
       dim3 blocks( 1, 1 );
    
       cudaMalloc( (void **)&d_1, sizeof(int) );
       cudaMalloc( (void **)&d_2, sizeof(int) );
    
       cudaMemcpy( d_1, a, sizeof(int), cudaMemcpyHostToDevice );
       cudaMemcpy( d_2, b, sizeof(int), cudaMemcpyHostToDevice );
    
       kernel<<< blocks, threads >>>( a, b );
    
       cudaMemcpy( a, d_1, sizeof(int), cudaMemcpyDeviceToHost );
       cudaMemcpy( b, d_2, sizeof(int), cudaMemcpyDeviceToHost );
    
       cudaFree(d_1);
       cudaFree(d_2);
    }