chore: import upstream snapshot with attribution

test/cpp/fluid/gather_test.cc

@@ -0,0 +1,50 @@
+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+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 "paddle/phi/kernels/funcs/gather.h"
+
+#include <gtest/gtest.h>
+
+#include "paddle/fluid/framework/tensor.h"
+#include "paddle/phi/common/place.h"
+
+TEST(Gather, GatherData) {
+  phi::DenseTensor* src = new phi::DenseTensor();
+  phi::DenseTensor* index = new phi::DenseTensor();
+  phi::DenseTensor* output = new phi::DenseTensor();
+
+  int* p_src = nullptr;
+  int* p_index = nullptr;
+  p_src = src->mutable_data<int>(common::make_ddim({3, 4}), phi::CPUPlace());
+  p_index = index->mutable_data<int>(common::make_ddim({2}), phi::CPUPlace());
+
+  for (int i = 0; i < 12; ++i) p_src[i] = i;
+  p_index[0] = 1;
+  p_index[1] = 0;
+
+  int* p_output =
+      output->mutable_data<int>(common::make_ddim({2, 4}), phi::CPUPlace());
+
+  auto* cpu_place = new phi::CPUPlace();
+  phi::CPUContext ctx(*cpu_place);
+  phi::funcs::CPUGather<int>(ctx, *src, *index, output);
+  delete cpu_place;
+  cpu_place = nullptr;
+  for (int i = 0; i < 4; ++i) EXPECT_EQ(p_output[i], i + 4);
+  for (int i = 4; i < 8; ++i) EXPECT_EQ(p_output[i], i - 4);
+
+  delete src;
+  delete index;
+  delete output;
+}