Merge pull request #4284 from qingqing01/lod_share

Pass LoD from input to output in the operators.

paddle/framework/backward.cc

@@ -166,9 +166,8 @@ static std::unique_ptr<OperatorBase> BackwardRecursive(
 
         // If part of input gradient of that operator is not calculated, fill
         // zero variables to that input gradient.
-        net->AppendOp(OpRegistry::CreateOp("fill_zeros_like",
-                                           {{"Src", {prefix}}},
-                                           {{"Dst", {grad_input}}}, {}));
+        net->AppendOp(OpRegistry::CreateOp("fill_zeros_like", {{"X", {prefix}}},
+                                           {{"Y", {grad_input}}}, {}));
       }
       return false;
     });

paddle/framework/backward_test.cc

@@ -127,8 +127,8 @@ class FillZeroOpMaker : public OpProtoAndCheckerMaker {
  public:
   FillZeroOpMaker(OpProto *proto, OpAttrChecker *op_checker)
       : OpProtoAndCheckerMaker(proto, op_checker) {
-    AddInput("Src", "x");
-    AddOutput("Dst", "out");
+    AddInput("X", "x");
+    AddOutput("Y", "out");
     AddComment("");
   }
 };
@@ -325,10 +325,10 @@ TEST(Backward, op_part_of_output_are_not_need) {
 
   auto &fill_zero = *net->ops_[0];
   ASSERT_EQ("fill_zeros_like", fill_zero.Type());
-  ASSERT_EQ(1UL, fill_zero.Inputs("Src").size());
-  ASSERT_EQ("Z", fill_zero.Input("Src"));
-  ASSERT_EQ(1UL, fill_zero.Outputs("Dst").size());
-  ASSERT_EQ(std::string("Z") + f::kZeroVarSuffix, fill_zero.Output("Dst"));
+  ASSERT_EQ(1UL, fill_zero.Inputs("X").size());
+  ASSERT_EQ("Z", fill_zero.Input("X"));
+  ASSERT_EQ(1UL, fill_zero.Outputs("Y").size());
+  ASSERT_EQ(std::string("Z") + f::kZeroVarSuffix, fill_zero.Output("Y"));
 
   auto &d_many_out = *net->ops_[1];
   ASSERT_EQ("many_output_op_grad", d_many_out.Type());

paddle/framework/operator.cc

@@ -207,23 +207,22 @@ const std::vector<const Tensor*> InferShapeContext::MultiInput<Tensor>(
 }
 
 template <>
-Tensor* ExecutionContext::Output<Tensor>(const std::string& name) const {
-  auto* var = OutputVar(name);
-  return var == nullptr ? nullptr : const_cast<Tensor*>(GetTensorFromVar(var));
+Tensor* InferShapeContext::Output<Tensor>(const std::string& name) const {
+  auto var = OutputVar(name);
+  return var == nullptr ? nullptr : var->GetMutable<LoDTensor>();
 }
 
 template <>
-std::vector<Tensor*> ExecutionContext::MultiOutput<Tensor>(
+std::vector<Tensor*> InferShapeContext::MultiOutput<Tensor>(
     const std::string& name) const {
   auto names = op().Outputs(name);
   std::vector<Tensor*> res;
   res.reserve(names.size());
   std::transform(names.begin(), names.end(), std::back_inserter(res),
                  [&](const std::string& sub_name) {
-                   auto var = scope().FindVar(sub_name);
-                   return var == nullptr
-                              ? nullptr
-                              : const_cast<Tensor*>(GetTensorFromVar(var));
+                   auto var = scope_.FindVar(sub_name);
+                   return var == nullptr ? nullptr
+                                         : var->GetMutable<LoDTensor>();
                  });
   return res;
 }

paddle/framework/operator.h

@@ -212,9 +212,9 @@ class InferShapeContext {
     return res;
   }
 
-  std::vector<const Variable*> MultiOutputVar(const std::string& name) const {
+  std::vector<Variable*> MultiOutputVar(const std::string& name) const {
     auto names = op_.Outputs(name);
-    std::vector<const Variable*> res;
+    std::vector<Variable*> res;
     res.reserve(names.size());
     std::transform(names.begin(), names.end(), std::back_inserter(res),
                    [this](const std::string& name) {
@@ -271,6 +271,20 @@ class InferShapeContext {
     return &var->Get<Tensor>();
   }
 
+  void ShareLoD(const std::string& in, const std::string& out, size_t i = 0,
+                size_t j = 0) const {
+    PADDLE_ENFORCE_LT(i, InputSize(in));
+    PADDLE_ENFORCE_LT(j, OutputSize(out));
+    auto* in_var = MultiInputVar(in)[i];
+    auto* out_var = MultiOutputVar(out)[j];
+    if (!in_var->IsType<LoDTensor>()) return;
+    PADDLE_ENFORCE(out_var->IsType<LoDTensor>(),
+                   "The %d-th output of Output(%s) must be LoDTensor.", j, out);
+    auto in_tensor = in_var->Get<LoDTensor>();
+    auto* out_tensor = out_var->GetMutable<LoDTensor>();
+    out_tensor->set_lod(in_tensor.lod());
+  }
+
  private:
   const OperatorBase& op_;
   const Scope& scope_;
@@ -283,6 +297,13 @@ template <>
 const std::vector<const Tensor*> InferShapeContext::MultiInput<Tensor>(
     const std::string& name) const;
 
+template <>
+Tensor* InferShapeContext::Output<Tensor>(const std::string& name) const;
+
+template <>
+std::vector<Tensor*> InferShapeContext::MultiOutput<Tensor>(
+    const std::string& name) const;
+
 template <typename T>
 struct EigenDeviceConverter;
 
@@ -315,38 +336,10 @@ class ExecutionContext : public InferShapeContext {
     return device_context_;
   }
 
-  // redefine Output function,
-  // use Variable::Get instead of Variable::GetMutable
-  template <typename T>
-  T* Output(const std::string& name) const {
-    auto var = OutputVar(name);
-    return var == nullptr ? nullptr : const_cast<T*>(&var->Get<T>());
-  }
-
-  // redefine MultiOutput function.
-  // use Variable::Get instead of Variable::GetMutable
-  template <typename T>
-  std::vector<T*> MultiOutput(const std::string& name) const {
-    auto names = op().Outputs(name);
-    std::vector<T*> res;
-    res.reserve(names.size());
-    std::transform(
-        names.begin(), names.end(), std::back_inserter(res),
-        [&](const std::string& sub_name) { return Output<T>(sub_name); });
-    return res;
-  }
-
  private:
   const platform::DeviceContext& device_context_;
 };
 
-template <>
-Tensor* ExecutionContext::Output<Tensor>(const std::string& name) const;
-
-template <>
-std::vector<Tensor*> ExecutionContext::MultiOutput<Tensor>(
-    const std::string& name) const;
-
 class OpKernel {
  public:
   /**

paddle/operators/accuracy_op.cc

@@ -39,7 +39,8 @@ class AccuracyOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(inference->dims()[0], label->dims()[0],
                       "inference size must be the same as label size");
 
-    ctx.Output<framework::LoDTensor>("Accuracy")->Resize({1});
+    ctx.Output<framework::Tensor>("Accuracy")->Resize({1});
+    ctx.ShareLoD("Inference", /*->*/ "Accuracy");
   }
 };
 
@@ -54,11 +55,15 @@ class AccuracyOpMaker : public framework::OpProtoAndCheckerMaker {
     // TODO(typhoonzero): AddInput("Weight", ...
     AddOutput("Accuracy", "The accuracy of current batch");
 
-    AddComment(
-        R"DOC(Accuracy. It will print accuracy rate for classification.
+    AddComment(R"DOC(
+Accuracy. It will print accuracy rate for classification.
 The accuracy is:
 ..  math::
-accuracy = \\frac{NumOfCorrectPredicts}{NumOfAllSamples})DOC");
+accuracy = \\frac{NumOfCorrectPredicts}{NumOfAllSamples})
+
+Both the input `Inference` and `Label` can carry the LoD (Level of Details)
+information, or not. But the output only shares the LoD with input `Inference`.
+)DOC");
   }
 };
 

paddle/operators/activation_op.cc

@@ -23,8 +23,9 @@ class ActivationOp : public framework::OperatorWithKernel {
 
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
-    ctx.Output<framework::LoDTensor>("Y")->Resize(
+    ctx.Output<framework::Tensor>("Y")->Resize(
         ctx.Input<framework::Tensor>("X")->dims());
+    ctx.ShareLoD("X", /*->*/ "Y");
   }
 };
 
@@ -34,7 +35,7 @@ class ActivationOpGrad : public framework::OperatorWithKernel {
 
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
-    ctx.Output<framework::LoDTensor>(framework::GradVarName("X"))
+    ctx.Output<framework::Tensor>(framework::GradVarName("X"))
         ->Resize(ctx.Input<framework::Tensor>("Y")->dims());
   }
 };

paddle/operators/add_op.cc

@@ -33,7 +33,7 @@ class AddOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(ctx.Input<Tensor>("X")->dims(),
                       ctx.Input<Tensor>("Y")->dims(),
                       "Two input of Add Op's dimension must be same.");
-    ctx.Output<framework::LoDTensor>("Out")->Resize(
+    ctx.Output<framework::Tensor>("Out")->Resize(
         ctx.Input<Tensor>("X")->dims());
   }
 };

paddle/operators/clip_op.cc

@@ -17,8 +17,6 @@
 namespace paddle {
 namespace operators {
 
-using framework::LoDTensor;
-
 class ClipOp : public framework::OperatorWithKernel {
  public:
   using framework::OperatorWithKernel::OperatorWithKernel;
@@ -29,11 +27,12 @@ class ClipOp : public framework::OperatorWithKernel {
                             "Input(X) of ClipOp should not be null.");
     PADDLE_ENFORCE_NOT_NULL(ctx.OutputVar("Out"),
                             "Output(Out) of ClipOp should not be null.");
-    auto x_dims = ctx.Input<LoDTensor>("X")->dims();
+    auto x_dims = ctx.Input<Tensor>("X")->dims();
     auto max = Attr<float>("max");
     auto min = Attr<float>("min");
     PADDLE_ENFORCE_LT(min, max, "max should be greater than min.");
-    ctx.Output<LoDTensor>("Out")->Resize(x_dims);
+    ctx.Output<Tensor>("Out")->Resize(x_dims);
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -66,8 +65,8 @@ class ClipOpGrad : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar("X"), "Input(X) should not be null");
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar(framework::GradVarName("Out")),
                             "Input(Out@GRAD) should not be null");
-    auto x_dims = ctx.Input<LoDTensor>("X")->dims();
-    auto *x_grad = ctx.Output<LoDTensor>(framework::GradVarName("X"));
+    auto x_dims = ctx.Input<Tensor>("X")->dims();
+    auto *x_grad = ctx.Output<Tensor>(framework::GradVarName("X"));
     if (x_grad != nullptr) {
       x_grad->Resize(x_dims);
     }

paddle/operators/concat_op.cc

@@ -29,7 +29,7 @@ class ConcatOp : public framework::OperatorWithKernel {
                             "Output(Out) of ConcatOp should not be null.");
 
     auto ins = ctx.MultiInput<framework::Tensor>("X");
-    auto *out = ctx.Output<framework::LoDTensor>("Out");
+    auto *out = ctx.Output<framework::Tensor>("Out");
     size_t axis = static_cast<size_t>(ctx.Attr<int>("axis"));
     size_t n = ins.size();
 

paddle/operators/conv2d_op.cc

@@ -37,7 +37,7 @@ class Conv2DOp : public framework::OperatorWithKernel {
 
     auto in = ctx.Input<Tensor>("Input");
     auto filter = ctx.Input<Tensor>("Filter");
-    auto out = ctx.Output<framework::LoDTensor>("Output");
+    auto out = ctx.Output<framework::Tensor>("Output");
     std::vector<int> strides = Attr<std::vector<int>>("strides");
     std::vector<int> paddings = Attr<std::vector<int>>("paddings");
     int groups = Attr<int>("groups");
@@ -111,10 +111,9 @@ class Conv2DOpGrad : public framework::OperatorWithKernel {
   void InferShape(const framework::InferShapeContext &ctx) const override {
     auto in = ctx.Input<Tensor>("Input");
     auto filter = ctx.Input<Tensor>("Filter");
-    auto d_in =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Input"));
+    auto d_in = ctx.Output<framework::Tensor>(framework::GradVarName("Input"));
     auto d_filter =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Filter"));
+        ctx.Output<framework::Tensor>(framework::GradVarName("Filter"));
     if (d_in) d_in->Resize(in->dims());
     if (d_filter) d_filter->Resize(filter->dims());
   }

paddle/operators/cos_sim_op.cc

@@ -54,9 +54,10 @@ class CosSimOp : public framework::OperatorWithKernel {
                    " just 1 (which will be broadcasted to match Input(X)).");
 
     // resize tensor
-    ctx.Output<framework::LoDTensor>("Out")->Resize({x_dims[0], 1});
-    ctx.Output<framework::LoDTensor>("XNorm")->Resize({x_dims[0], 1});
-    ctx.Output<framework::LoDTensor>("YNorm")->Resize({y_dims[0], 1});
+    ctx.Output<framework::Tensor>("Out")->Resize({x_dims[0], 1});
+    ctx.Output<framework::Tensor>("XNorm")->Resize({x_dims[0], 1});
+    ctx.Output<framework::Tensor>("YNorm")->Resize({y_dims[0], 1});
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -81,10 +82,13 @@ Cosine Similarity Operator.
 
 The equation is: Out = X^T * Y / (sqrt(X^T * X) * sqrt(Y^T * Y)).
 
-Input(X) and Input(Y) must have the same shape, except that the 1st dimension
-of Input(Y) could be just 1 (different from Input(X)), which will be
-broadcasted to match the shape of Input(X) before computing their cosine
+The input `X` and `Y` must have the same shape, except that the 1st dimension
+of input `Y` could be just 1 (different from input `X`), which will be
+broadcasted to match the shape of input `X` before computing their cosine
 similarity.
+
+Both the input `X` and `Y` can carry the LoD (Level of Details) information,
+or not. But the output only shares the LoD with input `X`.
 )DOC");
   }
 };
@@ -139,10 +143,8 @@ class CosSimOpGrad : public framework::OperatorWithKernel {
                       "Shape of Input(Out@Grad) must be [X.Dim(0), 1].");
 
     // resize tensor
-    auto *x_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
-    auto *y_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Y"));
+    auto *x_grad = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
+    auto *y_grad = ctx.Output<framework::Tensor>(framework::GradVarName("Y"));
     if (x_grad) x_grad->Resize(x_dims);
     if (y_grad) y_grad->Resize(y_dims);
   }

paddle/operators/crop_op.cc

@@ -19,7 +19,6 @@ namespace paddle {
 namespace operators {
 
 using framework::Tensor;
-using framework::LoDTensor;
 
 class CropOp : public framework::OperatorWithKernel {
  public:
@@ -31,9 +30,9 @@ class CropOp : public framework::OperatorWithKernel {
                             "Input(X) of CropOp should not be null.");
     PADDLE_ENFORCE_NOT_NULL(ctx.OutputVar("Out"),
                             "Output(Out) of CropOp should not be null.");
-    auto x_dim = ctx.Input<LoDTensor>("X")->dims();
-    auto *y = ctx.Input<LoDTensor>("Y");
-    auto *out = ctx.Output<LoDTensor>("Out");
+    auto x_dim = ctx.Input<Tensor>("X")->dims();
+    auto *y = ctx.Input<Tensor>("Y");
+    auto *out = ctx.Output<Tensor>("Out");
     if (y == nullptr) {
       auto shape = Attr<std::vector<int>>("shape");
       PADDLE_ENFORCE_EQ(
@@ -121,8 +120,8 @@ class CropOpGrad : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar("X"), "Input(X) should not be null");
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar(framework::GradVarName("Out")),
                             "Input(Out@GRAD) should not be null");
-    auto x_dims = ctx.Input<LoDTensor>("X")->dims();
-    auto *x_grad = ctx.Output<LoDTensor>(framework::GradVarName("X"));
+    auto x_dims = ctx.Input<Tensor>("X")->dims();
+    auto *x_grad = ctx.Output<Tensor>(framework::GradVarName("X"));
     if (x_grad != nullptr) {
       x_grad->Resize(x_dims);
     }

paddle/operators/cross_entropy_op.cc

@@ -17,8 +17,6 @@ limitations under the License. */
 namespace paddle {
 namespace operators {
 
-using framework::LoDTensor;
-
 class CrossEntropyOp : public framework::OperatorWithKernel {
  public:
   using framework::OperatorWithKernel::OperatorWithKernel;
@@ -51,7 +49,8 @@ class CrossEntropyOp : public framework::OperatorWithKernel {
                         "Input(Label) must be 1.");
     }
 
-    ctx.Output<LoDTensor>("Y")->Resize({x->dims()[0], 1});
+    ctx.Output<Tensor>("Y")->Resize({x->dims()[0], 1});
+    ctx.ShareLoD("X", /*->*/ "Y");
   }
 };
 
@@ -95,7 +94,7 @@ class CrossEntropyGradientOp : public framework::OperatorWithKernel {
                         "Input(Label) must be 1.");
     }
 
-    auto dx = ctx.Output<LoDTensor>(framework::GradVarName("X"));
+    auto dx = ctx.Output<Tensor>(framework::GradVarName("X"));
     dx->Resize(x->dims());
   }
 };
@@ -133,6 +132,9 @@ computation.
      As a special case of 2), when each row of Input(Label) has only one
      non-zero element (equals 1), soft-label cross-entropy degenerates to a
      one-hot cross-entropy with one-hot label representation.
+
+Both the input `X` and `Label` can carry the LoD (Level of Details) information,
+or not. But the output only shares the LoD with input `X`.
 )DOC");
   }
 };

paddle/operators/dropout_op.cc

@@ -18,7 +18,6 @@ namespace paddle {
 namespace operators {
 
 using framework::Tensor;
-using framework::LoDTensor;
 
 class DropoutOp : public framework::OperatorWithKernel {
  public:
@@ -34,10 +33,11 @@ class DropoutOp : public framework::OperatorWithKernel {
                    ctx.Attr<int>("is_training") == 1);
 
     auto dims = ctx.Input<Tensor>("X")->dims();
-    ctx.Output<LoDTensor>("Out")->Resize(dims);
+    ctx.Output<Tensor>("Out")->Resize(dims);
     if (ctx.Attr<int>("is_training") == 1) {
-      ctx.Output<LoDTensor>("Mask")->Resize(dims);
+      ctx.Output<Tensor>("Mask")->Resize(dims);
     }
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -96,7 +96,7 @@ class DropoutOpGrad : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(x_dims, mask_dims,
                       "Dimensions of Input(X) and Mask must be the same.");
 
-    auto *x_grad = ctx.Output<LoDTensor>(framework::GradVarName("X"));
+    auto *x_grad = ctx.Output<Tensor>(framework::GradVarName("X"));
     x_grad->Resize(x_dims);
   }
 };

paddle/operators/elementwise_mul_op.cc

@@ -37,7 +37,8 @@ class ElementWiseMulOp : public framework::OperatorWithKernel {
     auto y_dim = ctx.Input<Tensor>("Y")->dims();
     PADDLE_ENFORCE_GE(x_dim.size(), y_dim.size(),
                       "Rank of first input must >= rank of second input.")
-    ctx.Output<framework::LoDTensor>("Out")->Resize(x_dim);
+    ctx.Output<framework::Tensor>("Out")->Resize(x_dim);
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -63,11 +64,15 @@ Limited elementwise multiple operator.The equation is: Out = X ⊙ Y.
 2. Y's shape is a subset of X. 
    Y will be broadcasted to match the shape of X and axis should be dimension index Y in X.
    example:
+
       shape(X) = (2, 3, 4, 5), shape(Y) = (,)
       shape(X) = (2, 3, 4, 5), shape(Y) = (5,)
       shape(X) = (2, 3, 4, 5), shape(Y) = (4, 5)
       shape(X) = (2, 3, 4, 5), shape(Y) = (3, 4), with axis=1
       shape(X) = (2, 3, 4, 5), shape(Y) = (2), with axis=0
+
+Both the input X and Y can carry the LoD (Level of Details) information,
+or not. But the output only shares the LoD with input X.
 )DOC");
   }
 };
@@ -86,10 +91,8 @@ class ElementWiseMulOpGrad : public framework::OperatorWithKernel {
     auto x_dims = ctx.Input<Tensor>("X")->dims();
     auto y_dims = ctx.Input<Tensor>("Y")->dims();
     auto out_dims = ctx.Input<Tensor>(framework::GradVarName("Out"))->dims();
-    auto *x_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
-    auto *y_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Y"));
+    auto *x_grad = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
+    auto *y_grad = ctx.Output<framework::Tensor>(framework::GradVarName("Y"));
 
     PADDLE_ENFORCE_GE(x_dims.size(), y_dims.size(),
                       "Rank of first input must >= rank of second input.")

paddle/operators/fc_op.cc

@@ -186,6 +186,9 @@ W_i is a 2-D matrix of size (K x N), where N means the number of neurons
 in the fully connected layer. B is a 1-D vector of size N.
 Thus, the output Out is a 2-D matrix of size (M x N).
 Activation type can be set to `identity` (default), `sigmoid` or `softmax`.
+
+All the inputs can carry the LoD (Level of Details) information,
+or not. But the output only shares the LoD with first input (`X[0]`).
 )DOC");
   }
 };

paddle/operators/fill_zeros_like_op.cc

@@ -23,15 +23,14 @@ class FillZerosLikeOp : public framework::OperatorWithKernel {
 
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
-    PADDLE_ENFORCE_NOT_NULL(
-        ctx.InputVar("Src"),
-        "Input(Src) of FillZerosLikeOp should not be null.");
-    PADDLE_ENFORCE_NOT_NULL(
-        ctx.OutputVar("Dst"),
-        "Output(Dst) of FillZerosLikeOp should not be null.");
-
-    ctx.Output<framework::LoDTensor>("Dst")->Resize(
-        ctx.Input<framework::Tensor>("Src")->dims());
+    PADDLE_ENFORCE_NOT_NULL(ctx.InputVar("X"),
+                            "Input(X) of FillZerosLikeOp should not be null.");
+    PADDLE_ENFORCE_NOT_NULL(ctx.OutputVar("Y"),
+                            "Output(Y) of FillZerosLikeOp should not be null.");
+
+    ctx.Output<framework::Tensor>("Y")->Resize(
+        ctx.Input<framework::Tensor>("X")->dims());
+    ctx.ShareLoD("X", /*->*/ "Y");
   }
 };
 
@@ -40,8 +39,8 @@ class FillZerosLikeOpMaker : public framework::OpProtoAndCheckerMaker {
   FillZerosLikeOpMaker(framework::OpProto *proto,
                        framework::OpAttrChecker *op_checker)
       : framework::OpProtoAndCheckerMaker(proto, op_checker) {
-    AddInput("Src", "The input of fill-zeros-like op.");
-    AddOutput("Dst", "The varibale will be filled up with zeros.");
+    AddInput("X", "The input of fill-zeros-like op.");
+    AddOutput("Y", "The varibale will be filled up with zeros.");
     AddComment(R"DOC(
 Fill up a vriable with zeros.
 

paddle/operators/fill_zeros_like_op.h

@@ -23,7 +23,7 @@ template <typename Place, typename T>
 class FillZerosLikeKernel : public framework::OpKernel {
  public:
   void Compute(const framework::ExecutionContext& context) const override {
-    auto* output = context.Output<framework::Tensor>("Dst");
+    auto* output = context.Output<framework::Tensor>("Y");
     output->mutable_data<T>(context.GetPlace());
     auto t = framework::EigenVector<T>::Flatten(*output);
     t.device(context.GetEigenDevice<Place>()) = t.constant(static_cast<T>(0));

paddle/operators/gather_op.cc

@@ -35,7 +35,7 @@ class GatherOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_GE(batch_size, 0, "Batch size must be >0");
     framework::DDim output_dims(ctx.Input<Tensor>("X")->dims());
     output_dims[0] = batch_size;
-    ctx.Output<framework::LoDTensor>("Out")->Resize(output_dims);
+    ctx.Output<framework::Tensor>("Out")->Resize(output_dims);
   }
 };
 
@@ -45,7 +45,7 @@ class GatherGradOp : public framework::OperatorWithKernel {
 
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
-    auto X_grad = ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
+    auto X_grad = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
     auto X = ctx.Input<Tensor>("X");
 
     X_grad->Resize(X->dims());

paddle/operators/gaussian_random_op.cc

@@ -48,7 +48,7 @@ class GaussianRandomOp : public framework::OperatorWithKernel {
         ctx.OutputVar("Out"),
         "Output(Out) of GaussianRandomOp should not be null.");
 
-    auto* tensor = ctx.Output<framework::LoDTensor>("Out");
+    auto* tensor = ctx.Output<framework::Tensor>("Out");
     auto dims = Attr<std::vector<int>>("dims");
     std::vector<int64_t> temp;
     temp.reserve(dims.size());

paddle/operators/lookup_table_op.cc

@@ -32,9 +32,10 @@ class LookupTableOp : public framework::OperatorWithKernel {
 
     auto table_t = ctx.Input<Tensor>("W");
     auto ids_t = ctx.Input<Tensor>("Ids");
-    auto output_t = ctx.Output<framework::LoDTensor>("Out");
+    auto output_t = ctx.Output<framework::Tensor>("Out");
 
     output_t->Resize({ids_t->dims()[0], table_t->dims()[1]});
+    ctx.ShareLoD("Ids", /*->*/ "Out");
   }
 };
 
@@ -50,9 +51,13 @@ class LookupTableOpMaker : public framework::OpProtoAndCheckerMaker {
              "An input with type int32 or int64"
              "contains the ids to be looked up in W.");
     AddOutput("Out", "The lookup results, which have the same type with W.");
-    AddComment(
-        "This operator is used to perform lookups on the parameter W,"
-        "then concatenated into a dense tensor.");
+    AddComment(R"DOC(
+This operator is used to perform lookups on the parameter W,
+then concatenated into a dense tensor.
+
+The input `Ids` can carry the LoD (Level of Details) information,
+or not. And the output only shares the LoD with input `Ids`.
+)DOC");
   }
 };
 
@@ -64,7 +69,7 @@ class LookupTableOpGrad : public framework::OperatorWithKernel {
   void InferShape(const framework::InferShapeContext &context) const override {
     auto table = context.Input<Tensor>("W");
     auto d_table =
-        context.Output<framework::LoDTensor>(framework::GradVarName("W"));
+        context.Output<framework::Tensor>(framework::GradVarName("W"));
     d_table->Resize(table->dims());
   }
 };

paddle/operators/mean_op.cc

@@ -27,7 +27,7 @@ class MeanOp : public framework::OperatorWithKernel {
                             "Input(X) of MeanOp should not be null.");
     PADDLE_ENFORCE_NOT_NULL(ctx.OutputVar("Out"),
                             "Output(Out) of MeanOp should not be null.");
-    ctx.Output<framework::LoDTensor>("Out")->Resize({1});
+    ctx.Output<framework::Tensor>("Out")->Resize({1});
   }
 };
 
@@ -37,7 +37,8 @@ class MeanOpMaker : public framework::OpProtoAndCheckerMaker {
       : OpProtoAndCheckerMaker(proto, op_checker) {
     AddInput("X", "The input of mean op");
     AddOutput("Out", "The output of mean op").NotInGradient();
-    AddComment("Mean Operator");
+    AddComment(R"DOC( Mean Operator
+)DOC");
   }
 };
 
@@ -47,7 +48,7 @@ class MeanGradOp : public framework::OperatorWithKernel {
 
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
-    ctx.Output<framework::LoDTensor>(framework::GradVarName("X"))
+    ctx.Output<framework::Tensor>(framework::GradVarName("X"))
         ->Resize(ctx.Input<Tensor>("X")->dims());
   }
 };

paddle/operators/minus_op.cc

@@ -40,7 +40,8 @@ class MinusOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(
         left_tensor->numel(), right_tensor->numel(),
         "Minus operator must take two tensor with same num of elements");
-    ctx.Output<framework::LoDTensor>("Out")->Resize(left_tensor->dims());
+    ctx.Output<framework::Tensor>("Out")->Resize(left_tensor->dims());
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -54,7 +55,12 @@ class MinusOpMaker : public framework::OpProtoAndCheckerMaker {
 
     AddComment(R"DOC(Minus Operator
 
-Equation: Out = X - Y
+Equation:
+
+    Out = X - Y
+
+Both the input `X` and `Y` can carry the LoD (Level of Details) information,
+or not. But the output only shares the LoD with input `X`.
 )DOC");
   }
 };

paddle/operators/modified_huber_loss_op.cc

@@ -34,8 +34,8 @@ class ModifiedHuberLossOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(x->dims().size(), 2, "The tensor rank of X must be 2.");
     PADDLE_ENFORCE_EQ(x->dims()[1], 1, "The 2nd dimension of X must be 1.");
 
-    context.Output<framework::LoDTensor>("IntermediateVal")->Resize(x->dims());
-    context.Output<framework::LoDTensor>("Out")->Resize({x->dims()[0], 1});
+    context.Output<framework::Tensor>("IntermediateVal")->Resize(x->dims());
+    context.Output<framework::Tensor>("Out")->Resize({x->dims()[0], 1});
   }
 };
 
@@ -81,7 +81,7 @@ class ModifiedHuberLossGradOp : public framework::OperatorWithKernel {
     auto* intermediate_val = context.Input<Tensor>("IntermediateVal");
     auto* out_grad = context.Input<Tensor>(framework::GradVarName("Out"));
     auto* x_grad =
-        context.Output<framework::LoDTensor>(framework::GradVarName("X"));
+        context.Output<framework::Tensor>(framework::GradVarName("X"));
 
     PADDLE_ENFORCE_NOT_NULL(x, "X must be initialized.");
     PADDLE_ENFORCE_NOT_NULL(y, "Y must be initialized.");

paddle/operators/modified_huber_loss_op.h

@@ -52,8 +52,8 @@ class ModifiedHuberLossKernel : public framework::OpKernel {
   void Compute(const framework::ExecutionContext& context) const override {
     auto* in0 = context.Input<Tensor>("X");
     auto* in1 = context.Input<Tensor>("Y");
-    auto* out0 = context.Output<framework::LoDTensor>("IntermediateVal");
-    auto* out1 = context.Output<framework::LoDTensor>("Out");
+    auto* out0 = context.Output<framework::Tensor>("IntermediateVal");
+    auto* out1 = context.Output<framework::Tensor>("Out");
 
     out0->mutable_data<T>(context.GetPlace());
     out1->mutable_data<T>(context.GetPlace());
@@ -77,11 +77,9 @@ class ModifiedHuberLossGradCPUKernel : public framework::OpKernel {
  public:
   void Compute(const framework::ExecutionContext& context) const override {
     auto* in0 = context.Input<Tensor>("Y");
-    auto* in1 = context.Input<framework::LoDTensor>("IntermediateVal");
-    auto* in2 =
-        context.Input<framework::LoDTensor>(framework::GradVarName("Out"));
-    auto* out0 =
-        context.Output<framework::LoDTensor>(framework::GradVarName("X"));
+    auto* in1 = context.Input<framework::Tensor>("IntermediateVal");
+    auto* in2 = context.Input<framework::Tensor>(framework::GradVarName("Out"));
+    auto* out0 = context.Output<framework::Tensor>(framework::GradVarName("X"));
 
     if (out0) {
       const T* y_ptr = in0->data<T>();

paddle/operators/mul_op.cc

@@ -18,7 +18,6 @@ namespace paddle {
 namespace operators {
 
 using framework::Tensor;
-using framework::LoDTensor;
 
 class MulOp : public framework::OperatorWithKernel {
  public:
@@ -53,8 +52,9 @@ class MulOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(
         x_mat_dims[1], y_mat_dims[0],
         "First matrix's width must be equal with second matrix's height.");
-    ctx.Output<framework::LoDTensor>("Out")->Resize(
+    ctx.Output<framework::Tensor>("Out")->Resize(
         {x_mat_dims[0], y_mat_dims[1]});
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -83,9 +83,14 @@ class MulOpMaker : public framework::OpProtoAndCheckerMaker {
         .SetDefault(1)
         .EqualGreaterThan(1);
     AddComment(R"DOC(
-Two Element Mul Operator.
+Mul operator is used to perform matrix multiplication for input X and Y.
 
-The equation is: Out = X * Y
+The equation is:
+
+    Out = X * Y
+
+Both the input `X` and `Y` can carry the LoD (Level of Details) information,
+or not. But the output only shares the LoD with input `X`.
 )DOC");
   }
 };
@@ -103,10 +108,8 @@ class MulOpGrad : public framework::OperatorWithKernel {
     auto x_dims = ctx.Input<Tensor>("X")->dims();
     auto y_dims = ctx.Input<Tensor>("Y")->dims();
     auto out_dims = ctx.Input<Tensor>(framework::GradVarName("Out"))->dims();
-    auto *x_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
-    auto *y_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Y"));
+    auto *x_grad = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
+    auto *y_grad = ctx.Output<framework::Tensor>(framework::GradVarName("Y"));
 
     auto x_mat_dims =
         framework::flatten_to_2d(x_dims, Attr<int>("x_num_col_dims"));

paddle/operators/pad_op.cc

@@ -39,8 +39,13 @@ class PadOp : public framework::OperatorWithKernel {
     for (int i = 0; i < x_dim.size(); ++i) {
       out_dims[i] = x_dim[i] + paddings[i * 2] + paddings[i * 2 + 1];
     }
-    ctx.Output<framework::LoDTensor>("Out")->Resize(
+    ctx.Output<framework::Tensor>("Out")->Resize(
         framework::make_ddim(out_dims));
+    if (out_dims[0] == x_dim[0]) {
+      // Only pass LoD when the first dimension is equal between
+      // output and input.
+      ctx.ShareLoD("X", /*->*/ "Out");
+    }
   }
 };
 
@@ -101,7 +106,7 @@ class PadOpGrad : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar(framework::GradVarName("Out")),
                             "Input(Out@GRAD) should not be null");
     auto x_dims = ctx.Input<Tensor>("X")->dims();
-    auto *x_g = ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
+    auto *x_g = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
     if (x_g != nullptr) {
       x_g->Resize(x_dims);
     }

paddle/operators/prelu_op.cc

@@ -36,8 +36,9 @@ class PReluOp : public framework::OperatorWithKernel {
 
     PADDLE_ENFORCE_NOT_NULL(ctx.OutputVar("Out"),
                             "Output(Out) should not be null");
-    auto *out = ctx.Output<framework::LoDTensor>("Out");
+    auto *out = ctx.Output<framework::Tensor>("Out");
     out->Resize(in->dims());
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -55,6 +56,8 @@ The equation is:
   f(x) = alpha * x , for x < 0
   f(x) = x         , for x >= 0
 
+The input `X` can carry the LoD (Level of Details) information,
+or not. And the output shares the LoD with input `X`.
 )DOC");
   }
 };
@@ -69,11 +72,11 @@ class PReluGradOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar("X"), "Input(X) must not be null.");
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar(framework::GradVarName("Out")),
                             "Input(Out@GRAD) should not be null");
-    auto *dx = ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
+    auto *dx = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
     auto *x = ctx.Input<framework::Tensor>("X");
 
     auto *dalpha =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Alpha"));
+        ctx.Output<framework::Tensor>(framework::GradVarName("Alpha"));
     auto *alpha = ctx.Input<framework::Tensor>("Alpha");
 
     dx->Resize(x->dims());

paddle/operators/rank_loss_op.cc

@@ -40,7 +40,7 @@ class RankLossOp : public framework::OperatorWithKernel {
                    "All inputs must have the same size");
     PADDLE_ENFORCE((label_dims.size() == 2) && (label_dims[1] == 1),
                    "All inputs must be row vector with size batch_size x 1.");
-    ctx.Output<framework::LoDTensor>("Out")->Resize(label_dims);
+    ctx.Output<framework::Tensor>("Out")->Resize(label_dims);
   }
 };
 
@@ -102,9 +102,9 @@ class RankLossGradOp : public framework::OperatorWithKernel {
                             "Input(Out@GRAD) shouldn't be null.");
     auto dims = ctx.Input<framework::Tensor>("Left")->dims();
     auto *left_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Left"));
+        ctx.Output<framework::Tensor>(framework::GradVarName("Left"));
     auto *right_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Right"));
+        ctx.Output<framework::Tensor>(framework::GradVarName("Right"));
     if (left_grad) {
       left_grad->Resize(dims);
     }

paddle/operators/rank_loss_op.h

@@ -24,7 +24,7 @@ template <typename Place, typename T>
 class RankLossKernel : public framework::OpKernel {
  public:
   void Compute(const framework::ExecutionContext& ctx) const {
-    auto* out_t = ctx.Output<framework::LoDTensor>("Out");
+    auto* out_t = ctx.Output<framework::Tensor>("Out");
     auto* label_t = ctx.Input<framework::Tensor>("Label");
     auto* left_t = ctx.Input<framework::Tensor>("Left");
     auto* right_t = ctx.Input<framework::Tensor>("Right");
@@ -46,9 +46,9 @@ class RankLossGradKernel : public framework::OpKernel {
  public:
   void Compute(const framework::ExecutionContext& ctx) const {
     auto* d_left_t =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Left"));
+        ctx.Output<framework::Tensor>(framework::GradVarName("Left"));
     auto* d_right_t =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Right"));
+        ctx.Output<framework::Tensor>(framework::GradVarName("Right"));
 
     auto* d_out_t = ctx.Input<framework::Tensor>(framework::GradVarName("Out"));
     auto* label_t = ctx.Input<framework::Tensor>("Label");

paddle/operators/reshape_op.cc

@@ -50,7 +50,12 @@ class ReshapeOp : public framework::OperatorWithKernel {
     std::transform(shape.begin(), shape.end(), shape_int64.begin(),
                    [](int a) { return static_cast<int64_t>(a); });
     auto out_dims = framework::make_ddim(shape_int64);
-    ctx.Output<framework::LoDTensor>("Out")->Resize(out_dims);
+    ctx.Output<framework::Tensor>("Out")->Resize(out_dims);
+    if (shape[0] == in->dims()[0]) {
+      // Only pass LoD when the first dimension is equal between
+      // output and input.
+      ctx.ShareLoD("X", /*->*/ "Out");
+    }
   }
 };
 
@@ -94,7 +99,7 @@ class ReshapeGradOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar(framework::GradVarName("Out")),
                             "Input(Out@GRAD) shouldn't be null.");
     auto dims = ctx.Input<framework::Tensor>("X")->dims();
-    auto *d_in = ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
+    auto *d_in = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
     d_in->Resize(dims);
   }
 };

paddle/operators/rowwise_add_op.cc

@@ -44,7 +44,8 @@ class RowwiseAddOp : public framework::OperatorWithKernel {
         framework::slice_ddim(x_dims, num_col_dims, x_dims.size()), b_dims,
         "The width of two operands must be same");
     PADDLE_ENFORCE_EQ(ctx.OutputSize("Out"), 1, "The output size must be 1");
-    ctx.Output<framework::LoDTensor>("Out")->Resize(x_dims);
+    ctx.Output<framework::Tensor>("Out")->Resize(x_dims);
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -83,8 +84,8 @@ class RowwiseAddGradOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(
         framework::slice_ddim(x_dims, num_col_dims, x_dims.size()), b_dims,
         "The width of two operands must be same");
-    auto *dx = ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
-    auto *db = ctx.Output<framework::LoDTensor>(framework::GradVarName("b"));
+    auto *dx = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
+    auto *db = ctx.Output<framework::Tensor>(framework::GradVarName("b"));
     if (dx) dx->Resize(x_dims);
     if (db) db->Resize(b_dims);
   }

paddle/operators/scale_op.cc

@@ -33,8 +33,9 @@ class ScaleOp : public framework::OperatorWithKernel {
                             "Output(Out) of ScaleOp should not be null.");
 
     auto *in = ctx.Input<framework::Tensor>("X");
-    auto *out = ctx.Output<framework::LoDTensor>("Out");
+    auto *out = ctx.Output<framework::Tensor>("Out");
     out->Resize(in->dims());
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 

paddle/operators/scatter_op.cc

@@ -44,7 +44,7 @@ class ScatterOp : public framework::OperatorWithKernel {
     framework::DDim data_dim(ctx.Input<Tensor>("Updates")->dims());
     for (int i = 1; i < data_dim.size(); ++i)
       PADDLE_ENFORCE_EQ(data_dim[i], ctx.Input<Tensor>("Updates")->dims()[i]);
-    ctx.Output<framework::LoDTensor>("Out")->Resize(
+    ctx.Output<framework::Tensor>("Out")->Resize(
         ctx.Input<Tensor>("Ref")->dims());
   }
 };
@@ -56,10 +56,9 @@ class ScatterGradOp : public framework::OperatorWithKernel {
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     auto *dUpdates =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Updates"));
+        ctx.Output<framework::Tensor>(framework::GradVarName("Updates"));
     auto *Updates = ctx.Input<Tensor>("Updates");
-    auto *dRef =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Ref"));
+    auto *dRef = ctx.Output<framework::Tensor>(framework::GradVarName("Ref"));
     auto *Ref = ctx.Input<Tensor>("Ref");
 
     dRef->Resize(Ref->dims());

paddle/operators/sgd_op.cc

@@ -33,7 +33,7 @@ class SGDOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(ctx.Input<Tensor>("param")->dims(),
                       ctx.Input<Tensor>("grad")->dims(),
                       "Two input of SGD Op's dimension must be same.");
-    ctx.Output<framework::LoDTensor>("param_out")
+    ctx.Output<framework::Tensor>("param_out")
         ->Resize(ctx.Input<Tensor>("param")->dims());
   }
 };

paddle/operators/smooth_l1_loss_op.cc

@@ -44,8 +44,8 @@ class SmoothL1LossOp : public framework::OperatorWithKernel {
                         "The shape of OutsideWeight must be same as X.");
     }
 
-    auto* diff = ctx.Output<framework::LoDTensor>("Diff");
-    auto* out = ctx.Output<framework::LoDTensor>("Out");
+    auto* diff = ctx.Output<framework::Tensor>("Diff");
+    auto* out = ctx.Output<framework::Tensor>("Out");
     diff->Resize(x->dims());
     // loss is a two-rank tensor
     out->Resize({x->dims()[0], 1});
@@ -103,10 +103,8 @@ class SmoothL1LossGradOp : public framework::OperatorWithKernel {
     auto in_dims = ctx.Input<framework::Tensor>("X")->dims();
     auto out_dims =
         ctx.Input<framework::Tensor>(framework::GradVarName("Out"))->dims();
-    auto* x_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
-    auto* y_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Y"));
+    auto* x_grad = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
+    auto* y_grad = ctx.Output<framework::Tensor>(framework::GradVarName("Y"));
 
     PADDLE_ENFORCE_GE(out_dims.size(), 2,
                       "The tensor rank of Input(Out@Grad) should be 2.");

paddle/operators/softmax_op.cc

@@ -30,8 +30,7 @@ class SoftmaxOp : public framework::OperatorWithKernel {
 
     PADDLE_ENFORCE(ctx.Input<Tensor>("X")->dims().size() == 2UL,
                    "The input of softmax op must be a matrix.");
-    ctx.Output<framework::LoDTensor>("Y")->Resize(
-        ctx.Input<Tensor>("X")->dims());
+    ctx.Output<framework::Tensor>("Y")->Resize(ctx.Input<Tensor>("X")->dims());
   }
 };
 
@@ -77,7 +76,7 @@ class SoftmaxOpGrad : public framework::OperatorWithKernel {
                       ctx.Input<Tensor>(framework::GradVarName("Y"))->dims(),
                       "Input(Y) and its gradients should have a same shape.");
 
-    ctx.Output<framework::LoDTensor>(framework::GradVarName("X"))
+    ctx.Output<framework::Tensor>(framework::GradVarName("X"))
         ->Resize(ctx.Input<Tensor>("X")->dims());
   }
 };

paddle/operators/split_op.cc

@@ -27,7 +27,7 @@ class SplitOp : public framework::OperatorWithKernel {
   void InferShape(const framework::InferShapeContext &ctx) const override {
     // infershape
     auto *in = ctx.Input<framework::Tensor>("X");
-    auto outs = ctx.MultiOutput<framework::LoDTensor>("Out");
+    auto outs = ctx.MultiOutput<framework::Tensor>("Out");
     size_t axis = static_cast<size_t>(ctx.Attr<int>("axis"));
     size_t num = static_cast<size_t>(ctx.Attr<int>("num"));
     std::vector<int> sections =

paddle/operators/squared_l2_distance_op.cc

@@ -54,9 +54,10 @@ class SquaredL2DistanceOp : public framework::OperatorWithKernel {
                    "First dimension of target must be equal to input "
                    "or to 1.");
 
-    ctx.Output<framework::LoDTensor>("sub_result")
+    ctx.Output<framework::Tensor>("sub_result")
         ->Resize({x_dims[0], x->numel() / x_dims[0]});
-    ctx.Output<framework::LoDTensor>("Out")->Resize({x_dims[0], 1});
+    ctx.Output<framework::Tensor>("Out")->Resize({x_dims[0], 1});
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -79,6 +80,9 @@ class SquaredL2DistanceOpMaker : public framework::OpProtoAndCheckerMaker {
     input or to 1. If the first dimension of target is 1, SquaredL2DistanceOp
     will broadcast target's first dimension to input's first dimension.
     You can decide whether calculate the gradient of input and target.
+
+    Both the input X and Y can carry the LoD (Level of Details) information,
+    or not. But the output only shares the LoD with input X.
     )DOC");
   }
 };
@@ -100,10 +104,8 @@ class SquaredL2DistanceGradOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(out_dims[1], 1,
                       "Second dimension of output gradient "
                       "must be 1.");
-    auto* x_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
-    auto* y_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("Y"));
+    auto* x_grad = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
+    auto* y_grad = ctx.Output<framework::Tensor>(framework::GradVarName("Y"));
     if (x_grad) x_grad->Resize(x_dims);
     if (y_grad) y_grad->Resize(y_dims);
   }

paddle/operators/sum_op.cc

@@ -28,7 +28,7 @@ class SumOp : public framework::OperatorWithKernel {
                             "Output(Out) of SumOp should not be null.");
 
     auto ins = ctx.MultiInput<framework::Tensor>("X");
-    auto *out = ctx.Output<framework::LoDTensor>("Out");
+    auto *out = ctx.Output<framework::Tensor>("Out");
     int N = ins.size();
 
     auto in_dim = ins[0]->dims();
@@ -39,6 +39,7 @@ class SumOp : public framework::OperatorWithKernel {
       PADDLE_ENFORCE(in_dim == dim, "Input tensors must have same shape");
     }
     out->Resize(in_dim);
+    ctx.ShareLoD("X", /*->*/ "Out");
   }
 };
 
@@ -49,8 +50,11 @@ class SumOpMaker : public framework::OpProtoAndCheckerMaker {
     AddInput("X", "the input tensors of sum operator.").AsDuplicable();
     AddOutput("Out", "the output tensor of sum operator.");
     AddComment(R"DOC(
-            Sum the input tensors.
-        )DOC");
+Sum the input tensors.
+
+All the inputs can carry the LoD (Level of Details) information,
+or not. But the output only shares the LoD with the first input.
+)DOC");
   }
 };
 
@@ -61,7 +65,7 @@ class SumGradOp : public framework::OperatorWithKernel {
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     auto outputs =
-        ctx.MultiOutput<framework::LoDTensor>(framework::GradVarName("X"));
+        ctx.MultiOutput<framework::Tensor>(framework::GradVarName("X"));
     auto dims = ctx.Input<Tensor>(framework::GradVarName("Out"))->dims();
     for (auto output : outputs) {
       output->Resize(dims);

paddle/operators/top_k_op.cc

@@ -40,8 +40,8 @@ class TopkOp : public framework::OperatorWithKernel {
 
     framework::DDim dims = input->dims();
     dims[dims.size() - 1] = k;
-    ctx.Output<framework::LoDTensor>("Out")->Resize(dims);
-    ctx.Output<framework::LoDTensor>("Indices")->Resize(dims);
+    ctx.Output<framework::Tensor>("Out")->Resize(dims);
+    ctx.Output<framework::Tensor>("Indices")->Resize(dims);
   }
 };
 

paddle/operators/transpose_op.cc

@@ -51,7 +51,7 @@ class TransposeOp : public framework::OperatorWithKernel {
     for (size_t i = 0; i < axis_size; i++) {
       out_dims[i] = x_dims[axis[i]];
     }
-    ctx.Output<framework::LoDTensor>("Out")->Resize(out_dims);
+    ctx.Output<framework::Tensor>("Out")->Resize(out_dims);
   }
 };
 
@@ -99,8 +99,7 @@ class TransposeOpGrad : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_NOT_NULL(ctx.InputVar(framework::GradVarName("Out")),
                             "Input(Out@GRAD) should not be null");
     auto x_dims = ctx.Input<Tensor>("X")->dims();
-    auto *x_grad =
-        ctx.Output<framework::LoDTensor>(framework::GradVarName("X"));
+    auto *x_grad = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
 
     if (x_grad) x_grad->Resize(x_dims);
   }

paddle/operators/uniform_random_op.cc

@@ -54,7 +54,7 @@ class UniformRandomOp : public framework::OperatorWithKernel {
 
     PADDLE_ENFORCE(Attr<float>("min") < Attr<float>("max"),
                    "uniform_random's min must less then max");
-    auto* tensor = ctx.Output<framework::LoDTensor>("Out");
+    auto* tensor = ctx.Output<framework::Tensor>("Out");
     auto dims = Attr<std::vector<int>>("dims");
     std::vector<int64_t> temp;
     temp.reserve(dims.size());

python/paddle/v2/framework/tests/test_fill_zeros_like_op.py

@@ -6,8 +6,8 @@ from op_test import OpTest
 class TestFillZerosLikeOp(OpTest):
     def setUp(self):
         self.op_type = "fill_zeros_like"
-        self.inputs = {'Src': np.random.random((219, 232)).astype("float32")}
-        self.outputs = {'Dst': np.zeros_like(self.inputs["Src"])}
+        self.inputs = {'X': np.random.random((219, 232)).astype("float32")}
+        self.outputs = {'Y': np.zeros_like(self.inputs["X"])}
 
     def test_check_output(self):
         self.check_output()