sum_op support inplace

paddle/fluid/operators/sum_op.h

@@ -69,16 +69,33 @@ class SumKernel : public framework::OpKernel<T> {
         }
       }
     } else if (out_var->IsType<framework::SelectedRows>()) {
-      PADDLE_ENFORCE(!in_place, "SelectedRows not support inplace sum now");
-      auto *out = context.Output<SelectedRows>("Out");
-      out->mutable_rows()->clear();
+      if (in_place && in_vars.size() < 2) {
+        return;
+      }
 
       std::vector<const paddle::framework::SelectedRows *> inputs;
+      SelectedRows temp_in0;
 
-      for (auto &in_var : in_vars) {
-        inputs.push_back(&in_var->Get<SelectedRows>());
+      if (in_place) {
+        auto &in0 = in_vars[0]->Get<SelectedRows>();
+        temp_in0.set_height(in0.height());
+        temp_in0.set_rows(in0.rows());
+        framework::TensorCopy(in0.value(), in0.place(),
+                              context.device_context(),
+                              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>());
+        }
+      } else {
+        for (auto &in_var : in_vars) {
+          inputs.push_back(&in_var->Get<SelectedRows>());
+        }
       }
 
+      auto *out = context.Output<SelectedRows>("Out");
+      out->mutable_rows()->clear();
+
       math::scatter::MergeAdd<DeviceContext, T> merge_add;
       merge_add(context.template device_context<DeviceContext>(), inputs, out);
     } else if (out_var->IsType<framework::LoDTensorArray>()) {

python/paddle/fluid/tests/unittests/test_sum_op.py

@@ -45,17 +45,17 @@ class TestSumOp(OpTest):
 
 
 class TestSelectedRowsSumOp(OpTest):
-    def check_with_place(self, place):
+    def check_with_place(self, place, inplace):
         scope = core.Scope()
 
         self.height = 10
         self.row_numel = 12
         self.rows = [0, 1, 2, 3, 4, 5, 6]
 
-        self.check_input_and_optput(scope, place, True, True, True)
-        self.check_input_and_optput(scope, place, False, True, True)
-        self.check_input_and_optput(scope, place, False, False, True)
-        self.check_input_and_optput(scope, place, False, False, False)
+        self.check_input_and_optput(scope, place, inplace, True, True, True)
+        self.check_input_and_optput(scope, place, inplace, False, True, True)
+        self.check_input_and_optput(scope, place, inplace, False, False, True)
+        self.check_input_and_optput(scope, place, inplace, False, False, False)
 
     def _get_array(self, row_num, row_numel):
         array = np.ones((row_num, row_numel)).astype("float32")
@@ -66,6 +66,7 @@ class TestSelectedRowsSumOp(OpTest):
     def check_input_and_optput(self,
                                scope,
                                place,
+                               inplace,
                                w1_has_data=False,
                                w2_has_data=False,
                                w3_has_data=False):
@@ -75,10 +76,14 @@ class TestSelectedRowsSumOp(OpTest):
         self.create_selected_rows(scope, place, "W3", w3_has_data)
 
         # create Out Variable
-        out = scope.var('Out').get_selected_rows()
+        if inplace:
+            out_var_name = "W1"
+        else:
+            out_var_name = "Out"
+        out = scope.var(out_var_name).get_selected_rows()
 
         # create and run sum operator
-        sum_op = Operator("sum", X=["W1", "W2", "W3"], Out='Out')
+        sum_op = Operator("sum", X=["W1", "W2", "W3"], Out=out_var_name)
         sum_op.run(scope, place)
 
         has_data_w_num = 0
@@ -121,7 +126,8 @@ class TestSelectedRowsSumOp(OpTest):
         places = [core.CPUPlace()]
         # currently only support CPU
         for place in places:
-            self.check_with_place(place)
+            for inplace in [True, False]:
+                self.check_with_place(place, inplace)
 
 
 if __name__ == "__main__":