hello/hello.cu


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#include <cstdio>

void logDevices() {
  int count;
  if (cudaGetDeviceCount(&count) != cudaSuccess) {
    printf("No CUDA devices found\n");
    return;
  }

  printf("CUDA devices found: %d\n", count);
  for (int i = 0; i < count; ++i) {
    cudaDeviceProp properties;
    if (cudaGetDeviceProperties(&properties, i) == cudaSuccess) {
      printf("Device [%d]: %s\n", i, properties.name);
    }
  }
}

__global__ void kernel(int* array, int N) {
  for (int i = 0; i < N; ++i) {
    array[i] = i;
  }
}

int main() {
  logDevices();

  constexpr int N = 100;

  int* host_array   = new int[N];
  int* device_array = nullptr;
  bool success      = false;

  if (cudaMalloc(&device_array, N * sizeof(int)) != cudaSuccess) {
    goto cleanup;
  }

  kernel<<<1, 1>>>(device_array, N);

  if (cudaMemcpy(
          host_array, device_array, N * sizeof(int), cudaMemcpyDeviceToHost) !=
      cudaSuccess) {
    goto cleanup;
  }

  for (int i = 0; i < N; ++i) {
    printf("%d ", host_array[i]);
  }
  printf("\n");

  success = true;

cleanup:
  delete[] host_array;
  if (device_array != nullptr) {
    cudaFree(device_array);
  }
  return success ? 0 : 1;
}