Add Horovod distributed broadcast op to the bridge

Author: jianyinglang

src/ngraph_builder.cc

@@ -1599,6 +1599,16 @@ static Status TranslateDepthwiseConv2dNativeOp(
   return Status::OK();
 }
 
+static Status TranslateDistBroadcastOp(
+    const Node* op, const std::vector<const Tensor*>& static_input_map,
+    Builder::OpMap& ng_op_map) {
+  shared_ptr<ng::Node> ng_input;
+  TF_RETURN_IF_ERROR(GetInputNodes(ng_op_map, op, &ng_input));
+
+  SaveNgOp(ng_op_map, op->name(), make_shared<ng::op::DistBroadcast>(ng_input));
+  return Status::OK();
+}
+
 static Status TranslateExpandDimsOp(
     const Node* op, const std::vector<const Tensor*>& static_input_map,
     Builder::OpMap& ng_op_map) {
@@ -4070,6 +4080,7 @@ const static std::map<
         {"Greater", TranslateBinaryOp<ngraph::op::Greater>},
         {"GreaterEqual", TranslateBinaryOp<ngraph::op::GreaterEq>},
         {"HorovodAllreduce", TranslateAllreduceOp},
+        {"HorovodBroadcast", TranslateDistBroadcastOp},
         {"Identity", TranslateIdentityOp},
         {"L2Loss", TranslateL2LossOp},
         {"Less", TranslateBinaryOp<ngraph::op::Less>},

src/ngraph_mark_for_clustering.cc

@@ -256,6 +256,8 @@ Status MarkForClustering(Graph* graph) {
 #ifdef NGRAPH_DISTRIBUTED
       confirmation_function_map["HorovodAllreduce"] =
           SimpleConfirmationFunction();
+      confirmation_function_map["HorovodBroadcast"] =
+          SimpleConfirmationFunction();
 #endif
       confirmation_function_map["Identity"] = SimpleConfirmationFunction();
       confirmation_function_map["L2Loss"] = SimpleConfirmationFunction();
@@ -388,6 +390,7 @@ Status MarkForClustering(Graph* graph) {
       type_constraint_map["GreaterEqual"]["T"] = NGraphDTypes();
 #ifdef NGRAPH_DISTRIBUTED
       type_constraint_map["HorovodAllreduce"]["T"] = NGraphNumericDTypes();
+      type_constraint_map["HorovodBroadcast"]["T"] = NGraphNumericDTypes();
 #endif
       type_constraint_map["Identity"]["T"] = NGraphDTypes();
       type_constraint_map["L2Loss"]["T"] = NGraphNumericDTypes();