chore: import upstream snapshot with attribution

test/cpp/compat/ATen_equal_test.cc

@@ -0,0 +1,53 @@
+// Copyright (c) 2026 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 <ATen/Functions.h>
+#include <ATen/core/TensorBody.h>
+#include <ATen/cuda/CUDAContext.h>
+#include <ATen/ops/equal.h>
+#include <ATen/ops/tensor.h>
+#include <c10/core/Device.h>
+#include <c10/core/ScalarType.h>
+#include <c10/core/TensorOptions.h>
+
+#include "gtest/gtest.h"
+
+TEST(TensorEqualTest, DifferentShapeReturnsFalse) {
+  at::Tensor a = at::ones({2, 2}, at::kFloat);
+  at::Tensor b = at::ones({2, 3}, at::kFloat);
+
+  ASSERT_FALSE(at::equal(a, b));
+  ASSERT_FALSE(a.equal(b));
+}
+
+TEST(TensorEqualTest, DtypeMismatchCastsOtherTensor) {
+  at::Tensor a = at::tensor({1.0f, 2.0f, 3.0f}, at::kFloat);
+  at::Tensor b = at::tensor({1, 2, 3}, at::kInt);
+
+  ASSERT_TRUE(at::equal(a, b));
+  ASSERT_TRUE(a.equal(b));
+}
+
+#if defined(PADDLE_WITH_CUDA) || defined(PADDLE_WITH_HIP)
+TEST(TensorEqualTest, DeviceMismatchThrows) {
+  if (!at::cuda::is_available()) {
+    return;
+  }
+  at::Tensor cpu = at::ones({2, 2}, at::kFloat);
+  at::Tensor gpu =
+      at::ones({2, 2}, at::TensorOptions().dtype(at::kFloat).device(at::kCUDA));
+
+  ASSERT_THROW((void)at::equal(cpu, gpu), std::exception);
+}
+#endif