follow stab16, 1. finish dot (MPI version); 2. rename part of test files; 3. add switch function bewteen mpi and nccl, and be able to compile without nccl library. all the test run in x99 with 2 NV-P100.
follow stab16, 1. finish dot (MPI version); 2. rename part of test files; 3. add switch function bewteen mpi and nccl, and be able to compile without nccl library. all the test run in x99 with 2 NV-P100.