message: Fix the issue if (slot_num==0)
diff: @@ -466,6 +466,11 @@ public:
  TypeHashValueIndex *deltaw_hash_value_index,
  float *deltaw,
  float *hash_table_value) {
  +
  + if(slot_num == 0) {
  + return;
  + }
  +
  try {
  // step1: expand sample IDs
  dim3 blockSize(64, 1, 1);
  @@ -511,7 +516,6 @@ public:
  // }
  // }
  -
  // step3: sort by hash_value_index
  int end_bit = (int)log2((float)max_vocabulary_size_per_gpu) + 1;
  CK_CUDA_THROW_(cub::DeviceRadixSort::SortPairs(
  