sum op handle empty input

paddle/fluid/operators/math/selected_rows_functor.cc

@@ -269,12 +269,29 @@ struct MergeAdd<platform::CPUDeviceContext, T> {
   void operator()(const platform::CPUDeviceContext& context,
                   const std::vector<const framework::SelectedRows*>& inputs,
                   framework::SelectedRows* output) {
-    PADDLE_ENFORCE_GT(inputs.size(), 0, "should have at least one input");
-    auto input_width = inputs[0]->value().dims()[1];
-    auto input_height = inputs[0]->height();
+    if (inputs.size() == 0) {
+      VLOG(3) << "no input! return";
+      return;
+    }
+    const framework::SelectedRows* has_value_input = nullptr;
+    for (auto* in : inputs) {
+      if (!in->rows().empty()) {
+        has_value_input = in;
+        break;
+      }
+    }
+    if (has_value_input == nullptr) {
+      VLOG(3) << "no input has value! just return" << std::endl;
+      return;
+    }
+    auto input_width = has_value_input->value().dims()[1];
+    auto input_height = has_value_input->height();
     framework::SelectedRows& out = *output;
     std::set<int64_t> merged_row_set;
     for (auto* input : inputs) {
+      if (input->rows().empty()) {
+        continue;
+      }
       PADDLE_ENFORCE_EQ(input_width, input->value().dims()[1],
                         "all input should have same "
                         "dimension except for the first one");
@@ -288,7 +305,6 @@ struct MergeAdd<platform::CPUDeviceContext, T> {
     for (size_t i = 0; i < merge_rows.size(); ++i) {
       rows_to_id[merge_rows[i]] = i;
     }
-
     out.set_rows(merge_rows);
     out.set_height(input_height);
     out.mutable_value()->mutable_data<T>(
@@ -303,6 +319,9 @@ struct MergeAdd<platform::CPUDeviceContext, T> {
 
     auto blas = math::GetBlas<platform::CPUDeviceContext, T>(context);
     for (auto* input : inputs) {
+      if (input->rows().empty()) {
+        continue;
+      }
       auto* input_data = input->value().data<T>();
       auto& input_rows = input->rows();
 

paddle/fluid/operators/math/selected_rows_functor_test.cc

@@ -356,9 +356,7 @@ TEST(selected_rows_functor, cpu_merge_add_multi) {
   for (size_t i = 0; i < ret_rows.size(); ++i) {
     for (size_t j = 0; j < row_numel; ++j) {
       EXPECT_EQ(out_data[i * row_numel + j], ret_rows[i]);
-      std::cout << out_data[i * row_numel + j] << " ";
     }
-    std::cout << "\n";
   }
 }
 

paddle/fluid/operators/math/selected_rows_functor_test.cu

@@ -302,8 +302,6 @@ TEST(selected_rows_functor, gpu_merge_add) {
   for (size_t i = 0; i < ret_rows.size(); ++i) {
     for (size_t j = 0; j < row_numel; ++j) {
       EXPECT_EQ(out_data[i * row_numel + j], ret_rows[i]);
-      std::cout << out_data[i * row_numel + j] << " ";
     }
-    std::cout << "\n";
   }
 }

paddle/fluid/operators/sum_op.h

@@ -99,13 +99,19 @@ class SumKernel : public framework::OpKernel<T> {
                               temp_in0.mutable_value());
         inputs.push_back(&temp_in0);
         for (size_t i = 1; i < in_vars.size(); ++i) {
-          inputs.push_back(&in_vars[i]->Get<SelectedRows>());
+          auto &in = in_vars[i]->Get<SelectedRows>();
+          if (!in.rows().empty()) {
+            inputs.push_back(&in);
+          }
         }
       } else {
         for (auto &in_var : in_vars) {
+          auto &in = in_var->Get<SelectedRows>();
+          if (!in.rows().empty()) {
             inputs.push_back(&in_var->Get<SelectedRows>());
           }
         }
+      }
 
       auto *out = context.Output<SelectedRows>("Out");
       out->mutable_rows()->clear();