1  
 2  // noop
 3  void copy_to_cpu(tensor* t){
 4      if (DATA_COPY_DEBUG) printf("copy_to_cpu\n");
 5      if (t->device==CPU){
 6          return;
 7      }
 8      t->device = CPU;
 9  }
10  
11  // noop
12  tensor* copy_from_cpu(tensor* t) {
13      if (DATA_COPY_DEBUG) printf("copy_from_cpu\n");
14      t->device = CPU;
15      return t;
16  }
17  
18  void set_backend_cpu(void){
19      COPY_TO_DEVICE = copy_to_cpu;
20      COPY_FROM_DEVICE = copy_from_cpu;
21  }