$ cat t1800.cu
 __global__ void cudapipeline_harris(int  C, int  R, float* img, float* harris) {

     int idx = threadIdx.x + blockIdx.x * blockDim.x;
     int idy = threadIdx.y + blockIdx.y * blockDim.y;
     int idz = threadIdx.z + blockIdx.z * blockDim.z;

     float Ix[34][258];
     float Iy[34][258];
     float sum = 0;
     for (int i = 0; i < 34; i++)
       for (int j = 0; j < 258; j++){
         Ix[i][j] = threadIdx.x+j;
         Iy[i][j] = threadIdx.y+j;}
     for (int i = 0; i < 34; i++)
       for (int j = 0; j < 258; j++)
         sum += Ix[i][j] + Iy[i][j];
     *harris += sum;
}

int main(){
  float *d_img = NULL, *d_harris;
  cudaMalloc(&d_harris, 4);
  dim3 block(32,8,4);
  dim3 grid(32,8,4);
  cudapipeline_harris<<<grid, block>>>(0, 0, d_img, d_harris);
  cudaDeviceSynchronize();
}
$ nvcc -o t1800 t1800.cu
t1800.cu(3): warning: variable "idx" was declared but never referenced

t1800.cu(4): warning: variable "idy" was declared but never referenced

t1800.cu(5): warning: variable "idz" was declared but never referenced

$ cuda-memcheck ./t1800
========= CUDA-MEMCHECK
========= ERROR SUMMARY: 0 errors
$