fix GPU compile error problem

paddle/fluid/framework/fleet/nccl_wrapper.cc

@@ -24,33 +24,43 @@ std::shared_ptr<NCCLWrapper> NCCLWrapper::s_instance_ = NULL;
 bool NCCLWrapper::is_initialized_ = false;
 
 void NCCLWrapper::InitNCCL() {
+#ifdef PADDLE_WITH_CUDA
   PADDLE_ENFORCE(platform::dynload::ncclCommInitRank(
       &(nccl_info_.comm_), nccl_info_.global_ranks_, nccl_info_.nccl_id_,
       nccl_info_.my_global_rank_));
+#endif
   return;
 }
 
 void NCCLWrapper::SetNCCLId(const NCCLInfo& nccl_info) {
+#ifdef PADDLE_WITH_CUDA
   nccl_info_.nccl_id_ = nccl_info.nccl_id_;
+#endif
+  return;
 }
 
 NCCLInfo NCCLWrapper::GetNCCLId() {
+#ifdef PADDLE_WITH_CUDA
   PADDLE_ENFORCE(platform::dynload::ncclGetUniqueId(&(nccl_info_.nccl_id_)));
+#endif
   return nccl_info_;
 }
 
 void NCCLWrapper::SetRankInfo(const int local_rank, const int global_rank,
                               const int ranks) {
+#ifdef PADDLE_WITH_CUDA
   nccl_info_.local_rank_ = local_rank;
   nccl_info_.my_global_rank_ = global_rank;
   nccl_info_.global_ranks_ = ranks;
   PADDLE_ENFORCE(cudaSetDevice(local_rank));
   PADDLE_ENFORCE(cudaStreamCreate(&(nccl_info_.stream_)));
+#endif
   return;
 }
 
 void NCCLWrapper::SyncVar(const int root_rank, const Scope& scope,
                           const std::vector<std::string>& var_names) {
+#ifdef PADDLE_WITH_CUDA
   for (auto& name : var_names) {
     auto var = scope.FindVar(name);
     LoDTensor* tensor = var->GetMutable<LoDTensor>();
@@ -60,6 +70,8 @@ void NCCLWrapper::SyncVar(const int root_rank, const Scope& scope,
         root_rank, nccl_info_.comm_, nccl_info_.stream_));
     cudaStreamSynchronize(nccl_info_.stream_);
   }
+#endif
+  return;
 }
 
 }  // end namespace framework

paddle/fluid/framework/fleet/nccl_wrapper.h

@@ -24,7 +24,9 @@ limitations under the License. */
 #include "paddle/fluid/framework/program_desc.h"
 #include "paddle/fluid/framework/scope.h"
 #include "paddle/fluid/framework/variable_helper.h"
+#ifdef PADDLE_WITH_CUDA
 #include "paddle/fluid/platform/dynload/nccl.h"
+#endif
 #include "paddle/fluid/platform/macros.h"  // for DISABLE_COPY_AND_ASSIGN
 
 namespace paddle {
@@ -39,9 +41,11 @@ class NCCLInfo {
   int local_rank_;
   int global_ranks_;
   int my_global_rank_;
+#ifdef PADDLE_WITH_CUDA
   ncclUniqueId nccl_id_;
   ncclComm_t comm_;
   cudaStream_t stream_;
+#endif
 };
 
 class NCCLWrapper {