gather op added

paddle/framework/CMakeLists.txt

@@ -10,6 +10,8 @@ cc_test(eigen_test SRCS eigen_test.cc DEPS tensor)
 cc_library(lod_tensor SRCS lod_tensor.cc DEPS ddim place tensor)
 cc_test(lod_tensor_test SRCS lod_tensor_test.cc DEPS lod_tensor)
 
+cc_test(empty_test SRCS	empty_test.cc DEPS tensor)
+
 cc_test(variable_test SRCS variable_test.cc)
 
 cc_library(scope SRCS scope.cc)

paddle/framework/empty_test.cc

@@ -0,0 +1,56 @@
+/*
+  Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+  http://www.apache.org/licenses/LICENSE-2.0
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+
+#include <gtest/gtest.h>
+#include <string>
+#include "paddle/framework/tensor.h"
+
+TEST(Empty, Dims) {
+  using namespace paddle::framework;
+  using namespace paddle::platform;
+  Tensor tt;
+  tt.Resize(make_ddim({0, 3, 4}));
+  DDim dims = tt.dims();
+  ASSERT_EQ(arity(dims), 3);
+  EXPECT_EQ(0, dims[0]);
+  EXPECT_EQ(3, dims[1]);
+  EXPECT_EQ(4, dims[2]);
+}
+
+TEST(Empty, MutableData) {
+  using namespace paddle::framework;
+  using namespace paddle::platform;
+  {
+    Tensor src_tensor;
+    float* p1 = nullptr;
+    // initialization
+    p1 = src_tensor.mutable_data<float>(make_ddim({0, 2, 3}), CPUPlace());
+    EXPECT_NE(p1, nullptr);
+  }
+
+#ifndef PADDLE_ONLY_CPU
+  {
+    Tensor src_tensor;
+    float* p1 = nullptr;
+    float* p2 = nullptr;
+    // initialization
+    p1 = src_tensor.mutable_data<float>(make_ddim({0, 2, 3}), GPUPlace());
+    EXPECT_NE(p1, nullptr);
+    // set src_tensor a new dim with large size
+    // momery is supposed to be re-allocated
+    p2 = src_tensor.mutable_data<float>(make_ddim({0, 4}), GPUPlace());
+    EXPECT_NE(p2, nullptr);
+    // EXPECT_NE(p1, p2);
+  }
+#endif
+}

paddle/operators/gather_op.cc

@@ -23,6 +23,8 @@ class GatherOp : public framework::OperatorWithKernel {
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE(ctx.InputSize() == 2, "");
     PADDLE_ENFORCE(ctx.OutputSize() == 1, "");
+    PADDLE_ENFORCE_NOT_NULL(ctx.InputVar(0),
+                            "Inputs of GatherOp must all be set");
     int batch_size = ctx.Input<Tensor>(1)->dims()[0];
     PADDLE_ENFORCE(batch_size > 0);
   }