test_slice_op.py

#   Copyright (c) 2018 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.

import unittest

import gradient_checker
import numpy as np
from decorator_helper import prog_scope
from op_test import OpTest, convert_float_to_uint16

import paddle
import paddle.fluid as fluid
import paddle.fluid.core as core
from paddle.tensor.manipulation import tensor_array_to_tensor

paddle.enable_static()


# Situation 1: starts(list, no tensor), ends(list, no tensor)
# 1.1 without attr(decrease)
class TestSliceOp(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.prim_op_type = "prim"
        self.python_api = paddle.slice
        self.public_python_api = paddle.slice
        self.config()
        self.inputs = {'Input': self.input}
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            'starts': self.starts,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
        }

    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [3, 3, 4]
        self.axes = [0, 1, 2]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[1:3, 0:3, 2:4, :]

    def test_check_output(self):
        self.check_output()

    def test_check_grad_normal(self):
        self.check_grad(
            ['Input'], 'Out', max_relative_error=0.006, check_prim=True
        )


class TestCase1(TestSliceOp):
    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [-3, 0, 2]
        self.ends = [3, 100, -1]
        self.axes = [0, 1, 2]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[-3:3, 0:100, 2:-1, :]


class TestCase2(TestSliceOp):
    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [-3, 0, 2]
        self.ends = [3, 100, -1]
        self.axes = [0, 1, 3]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[-3:3, 0:100, :, 2:-1]


class TestSliceZerosShapeTensor(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.prim_op_type = "prim"
        self.python_api = paddle.slice
        self.public_python_api = paddle.slice
        self.config()
        self.inputs = {'Input': self.input}
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            'starts': self.starts,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
            'use_mkldnn': True,
        }

    def config(self):
        self.input = np.random.random([0, 0, 0]).astype("float32")
        self.starts = [1]
        self.ends = [2]
        self.axes = [0]
        self.infer_flags = []
        self.out = self.input[1:2]

    def test_check_output(self):
        self.check_output_with_place(paddle.CPUPlace())


# 1.2 with attr(decrease)
class TestSliceOp_decs_dim(OpTest):
    def setUp(self):
        self.enable_cinn = True
        self.op_type = "slice"
        self.prim_op_type = "prim"
        self.python_api = paddle.slice
        self.public_python_api = paddle.slice
        self.config()
        self.inputs = {'Input': self.input}
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            'starts': self.starts,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
            'decrease_axis': self.decrease_axis,
        }

    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [2, 3, 4]
        self.axes = [0, 1, 2]
        self.decrease_axis = [0]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[1, 0:3, 2:4, :]

    def test_check_output(self):
        self.check_output()

    def test_check_grad_normal(self):
        self.check_grad(
            ['Input'], 'Out', max_relative_error=0.006, check_prim=True
        )


class TestSliceOp_decs_dim_2(TestSliceOp_decs_dim):
    def config(self):
        self.enable_cinn = True
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [2, 1, 4]
        self.axes = [0, 1, 2]
        self.decrease_axis = [0, 1]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[1, 0, 2:4, :]


class TestSliceOp_decs_dim_3(TestSliceOp_decs_dim):
    def config(self):
        self.enable_cinn = True
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [-1, 0, 2]
        self.ends = [1000000, 1, 4]
        self.axes = [0, 1, 2]
        self.decrease_axis = [0, 1]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[-1, 0, 2:4, :]


class TestSliceOp_decs_dim_4(TestSliceOp_decs_dim):
    def config(self):
        self.enable_cinn = True
        self.input = np.random.random([3, 4, 5, 7]).astype("float64")
        self.starts = [0, 1, 2, 3]
        self.ends = [1, 2, 3, 4]
        self.axes = [0, 1, 2, 3]
        self.decrease_axis = [0, 1, 2, 3]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[0, 1, 2, 3:4]


class TestSliceOp_decs_dim_5(TestSliceOp_decs_dim):
    def config(self):
        self.enable_cinn = True
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [-1]
        self.ends = [1000000]
        self.axes = [3]
        self.decrease_axis = [3]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[:, :, :, -1]


# test_6 with test_2 with test_3
class TestSliceOp_decs_dim_6(TestSliceOp_decs_dim):
    def config(self):
        self.enable_cinn = True
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [0, 1, 2, 3]
        self.ends = [1, 2, 3, 4]
        self.axes = [0, 1, 2, 3]
        self.decrease_axis = [0, 1, 2, 3]
        self.infer_flags = [1, 1, 1]
        self.out = self.input[0, 1, 2, 3:4]


# Situation 2: starts(list, have tensor), ends(list, no tensor)
# without attr(decrease)
class TestSliceOp_starts_ListTensor(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.python_api = paddle.slice
        self.config()

        starts_tensor = []
        for index, ele in enumerate(self.starts):
            starts_tensor.append(
                ("x" + str(index), np.ones((1)).astype('int64') * ele)
            )

        self.inputs = {'Input': self.input, 'StartsTensorList': starts_tensor}
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            'starts': self.starts_infer,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
        }

    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [3, 3, 4]
        self.axes = [0, 1, 2]
        self.infer_flags = [-1, 1, -1]
        self.out = self.input[1:3, 0:3, 2:4, :]

        self.starts_infer = [-1, 0, -1]

    def test_check_output(self):
        self.check_output()

    def test_check_grad_normal(self):
        self.check_grad(['Input'], 'Out', max_relative_error=0.006)


# Situation 2: starts(list, have tensor), ends(list, no tensor)
#  with attr(decrease)
class TestSliceOp_decs_dim_starts_ListTensor(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.python_api = paddle.slice
        self.config()

        starts_tensor = []
        for index, ele in enumerate(self.starts):
            starts_tensor.append(
                ("x" + str(index), np.ones((1)).astype('int32') * ele)
            )

        self.inputs = {'Input': self.input, 'StartsTensorList': starts_tensor}

        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            'starts': self.starts_infer,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
            'decrease_axis': self.decrease_axis,
        }

    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [2, 3, 4]
        self.axes = [0, 1, 2]
        self.decrease_axis = [0]
        self.infer_flags = [1, -1, 1]
        self.out = self.input[1, 0:3, 2:4, :]

        self.starts_infer = [1, -1, 2]

    def test_check_output(self):
        self.check_output()

    def test_check_grad_normal(self):
        self.check_grad(['Input'], 'Out', max_relative_error=0.006)


class TestSliceOp_decs_dim_5_starts_ListTensor(
    TestSliceOp_decs_dim_starts_ListTensor
):
    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [-1]
        self.ends = [1000000]
        self.axes = [3]
        self.decrease_axis = [3]
        self.infer_flags = [-1]
        self.out = self.input[:, :, :, -1]

        self.starts_infer = [-1]


# Situation 3: starts(tensor), ends(list, no tensor)
# with attr(decrease)
class TestSliceOp_decs_dim_starts_OneTensor(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.python_api = paddle.slice
        self.config()
        self.inputs = {
            'Input': self.input,
            "StartsTensor": np.array(self.starts, dtype="int32"),
        }
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            # 'starts': self.starts,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
            'decrease_axis': self.decrease_axis,
        }

    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [2, 3, 4]
        self.axes = [0, 1, 2]
        self.decrease_axis = [0]
        self.infer_flags = [-1, -1, -1]
        self.out = self.input[1, 0:3, 2:4, :]

    def test_check_output(self):
        self.check_output()

    def test_check_grad_normal(self):
        self.check_grad(['Input'], 'Out', max_relative_error=0.006)


# Situation 4: starts(tensor), ends(tensor)
#  without attr(decrease)
class TestSliceOp_starts_OneTensor_ends_OneTensor(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.python_api = paddle.slice
        self.config()

        self.inputs = {
            'Input': self.input,
            "StartsTensor": np.array(self.starts, dtype="int64"),
            "EndsTensor": np.array(self.ends, dtype="int32"),
        }
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            # 'starts': self.starts,
            # 'ends': self.ends_infer,
            'infer_flags': self.infer_flags,
        }

    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [3, 3, 4]
        self.axes = [0, 1, 2]
        self.infer_flags = [-1, -1, -1]
        self.out = self.input[1:3, 0:3, 2:4, :]

    def test_check_output(self):
        self.check_output()

    def test_check_grad_normal(self):
        self.check_grad(['Input'], 'Out', max_relative_error=0.006)


# Situation 5: starts(tensor), ends(tensor)
#  with attr(decrease)
class TestSliceOp_decs_dim_starts_and_ends_OneTensor(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.python_api = paddle.slice
        self.config()
        self.inputs = {
            'Input': self.input,
            "StartsTensor": np.array(self.starts, dtype="int32"),
            "EndsTensor": np.array(self.ends, dtype="int32"),
        }
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            # 'starts': self.starts,
            # 'ends': self.ends,
            'infer_flags': self.infer_flags,
            'decrease_axis': self.decrease_axis,
        }

    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [2, 1, 4]
        self.axes = [0, 1, 2]
        self.decrease_axis = [0, 1]
        self.infer_flags = [-1, -1, -1]
        self.out = self.input[1, 0, 2:4, :]

    def test_check_output(self):
        self.check_output()

    def test_check_grad_normal(self):
        self.check_grad(['Input'], 'Out', max_relative_error=0.006)


# Situation 6: starts(tensor), ends(list, have tensor)
# without attr(decrease)
class TestSliceOp_starts_OneTensor_ends_ListTensor(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.python_api = paddle.slice
        self.config()

        ends_tensor = []
        for index, ele in enumerate(self.ends):
            ends_tensor.append(
                ("y" + str(index), np.ones((1)).astype('int32') * ele)
            )

        self.inputs = {
            'Input': self.input,
            "StartsTensor": np.array(self.starts, dtype="int32"),
            'EndsTensorList': ends_tensor,
        }
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            # 'starts': self.starts,
            'ends': self.ends_infer,
            'infer_flags': self.infer_flags,
        }

    def config(self):
        self.input = np.random.random([3, 4, 5, 6]).astype("float64")
        self.starts = [1, 0, 2]
        self.ends = [3, 3, 4]
        self.axes = [0, 1, 2]
        self.infer_flags = [-1, -1, -1]
        self.out = self.input[1:3, 0:3, 2:4, :]

        self.ends_infer = [-1, 3, 4]

    def test_check_output(self):
        self.check_output()

    def test_check_grad_normal(self):
        self.check_grad(['Input'], 'Out', max_relative_error=0.006)


# Test CUDA float16
@unittest.skipIf(
    not core.is_compiled_with_cuda(), "core is not compiled with CUDA"
)
class TestFP16(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.prim_op_type = "prim"
        self.python_api = paddle.slice
        self.public_python_api = paddle.slice
        self.config()
        self.inputs = {'Input': self.input}
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            'starts': self.starts,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
        }

    def config(self):
        self.dtype = "float16"
        self.input = np.random.random([3, 4, 5, 6]).astype(self.dtype)
        self.starts = [-3, 0, 2]
        self.ends = [3, 100, -1]
        self.axes = [0, 1, 3]
        self.out = self.input[-3:3, 0:100, :, 2:-1]
        self.infer_flags = [1, 1, 1]

    def test_check_output(self):
        place = core.CUDAPlace(0)
        if core.is_float16_supported(place):
            self.check_output_with_place(place, check_prim=True)

    def test_check_grad_normal(self):
        place = core.CUDAPlace(0)
        print("core:", core.is_float16_supported(place))
        if core.is_float16_supported(place):
            self.check_grad_with_place(
                place,
                ['Input'],
                'Out',
                check_prim=True,
            )


@unittest.skipIf(
    not core.is_compiled_with_cuda(), "core is not compiled with CUDA"
)
class TestFP16_2(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.prim_op_type = "prim"
        self.python_api = paddle.slice
        self.public_python_api = paddle.slice
        self.config()
        self.inputs = {'Input': self.input}
        self.outputs = {'Out': self.out}
        self.attrs = {
            'axes': self.axes,
            'starts': self.starts,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
        }

    def config(self):
        self.dtype = "float16"
        self.input = np.random.random([3, 4, 10]).astype(self.dtype)
        self.starts = [0]
        self.ends = [1]
        self.axes = [1]
        self.out = self.input[:, 0:1, :]
        self.infer_flags = [1]

    def test_check_output(self):
        place = core.CUDAPlace(0)
        if core.is_float16_supported(place):
            self.check_output_with_place(place, check_prim=True)

    def test_check_grad_normal(self):
        place = core.CUDAPlace(0)
        if core.is_float16_supported(place):
            self.check_grad_with_place(
                place,
                ['Input'],
                'Out',
                numeric_grad_delta=0.5,
                check_prim=True,
            )


class TestBF16(OpTest):
    def setUp(self):
        self.op_type = "slice"
        self.prim_op_type = "prim"
        self.python_api = paddle.slice
        self.public_python_api = paddle.slice
        self.config()
        self.inputs = {'Input': convert_float_to_uint16(self.input)}
        self.outputs = {'Out': convert_float_to_uint16(self.out)}
        self.attrs = {
            'axes': self.axes,
            'starts': self.starts,
            'ends': self.ends,
            'infer_flags': self.infer_flags,
        }

    def config(self):
        self.dtype = np.uint16
        self.input = np.random.random([3, 4, 5, 6]).astype(np.float32)
        self.starts = [-3, 0, 2]
        self.ends = [3, 100, -1]
        self.axes = [0, 1, 3]
        self.out = self.input[-3:3, 0:100, :, 2:-1]
        self.infer_flags = [1, 1, 1]

    def test_check_output(self):
        self.check_output()

    # pad not support bfloat16, so we can't test prim.
    def test_check_grad_normal(self):
        self.check_grad(['Input'], 'Out')


# Test python API
class TestSliceAPI(unittest.TestCase):
    def test_1(self):
        input = np.random.random([3, 4, 5, 6]).astype("float64")
        minus_1 = paddle.tensor.fill_constant([1], "int32", -1)
        minus_3 = paddle.tensor.fill_constant([1], "int64", -3)
        starts = paddle.static.data(
            name='starts', shape=[1, 3], dtype="float32"
        )
        starts.desc.set_need_check_feed(False)
        ends = paddle.static.data(name='ends', shape=[3], dtype="float32")
        ends.desc.set_need_check_feed(False)
        x = paddle.static.data(
            name="x",
            shape=[3, 4, 5, 6],
            dtype="float64",
        )

        # value_int64 is greater than 2147483647 which is the max of int32
        value_int64 = paddle.tensor.fill_constant([1], "int64", 2147483648)

        out_1 = paddle.slice(
            x, axes=[0, 1, 2], starts=[-3, 0, 2], ends=[value_int64, 100, -1]
        )
        out_2 = paddle.slice(
            x, axes=[0, 1, 3], starts=[minus_3, 0, 2], ends=[3, 100, -1]
        )
        out_3 = paddle.slice(
            x, axes=[0, 1, 3], starts=[minus_3, 0, 2], ends=[3, 100, minus_1]
        )
        out_4 = paddle.slice(x, axes=[0, 1, 2], starts=starts, ends=ends)

        out_5 = x[-3:3, 0:100, 2:-1]
        out_6 = x[minus_3:3, 0:100, :, 2:-1]
        out_7 = x[minus_1, 0:100, :, 2:minus_1]

        exe = fluid.Executor(place=fluid.CPUPlace())
        res_1, res_2, res_3, res_4, res_5, res_6, res_7 = exe.run(
            fluid.default_main_program(),
            feed={
                "x": input,
                'starts': np.array([-3, 0, 2]).astype("int32"),
                'ends': np.array([3, 100, -1]).astype("int32"),
            },
            fetch_list=[out_1, out_2, out_3, out_4, out_5, out_6, out_7],
        )

        assert np.array_equal(res_1, input[-3:3, 0:100, 2:-1, :])
        assert np.array_equal(res_2, input[-3:3, 0:100, :, 2:-1])
        assert np.array_equal(res_3, input[-3:3, 0:100, :, 2:-1])
        assert np.array_equal(res_4, input[-3:3, 0:100, 2:-1, :])
        assert np.array_equal(res_5, input[-3:3, 0:100, 2:-1, :])
        assert np.array_equal(res_6, input[-3:3, 0:100, :, 2:-1])
        assert np.array_equal(res_7, input[-1, 0:100, :, 2:-1])


class TestSliceApiWithTensor(unittest.TestCase):
    def test_starts_ends_is_tensor(self):
        with paddle.fluid.dygraph.guard():
            a = paddle.rand(shape=[4, 5, 6], dtype='float32')
            axes = [0, 1, 2]
            starts = [-3, 0, 2]
            ends = [3, 2, 4]
            a_1 = paddle.slice(
                a,
                axes=axes,
                starts=paddle.to_tensor(starts, dtype='int32'),
                ends=paddle.to_tensor(ends, dtype='int32'),
            )
            a_2 = paddle.slice(a, axes=axes, starts=starts, ends=ends)

            np.testing.assert_array_equal(a_1.numpy(), a_2.numpy())

    def test_bool_tensor(self):
        with paddle.fluid.dygraph.guard():
            array = (np.arange(60).reshape([3, 4, 5]) % 3).astype('bool')
            tt = paddle.to_tensor(array)
            tt.stop_gradient = False

            starts = [0, 1, 2]
            ends = [3, 5, 4]
            axes = [0, 1, 2]

            y_paddle = paddle.slice(tt, axes, starts, ends)
            y_np = tt[0:3, 1:5, 2:4]

            self.assertTrue(paddle.bool == y_paddle.dtype)
            np.testing.assert_array_equal(y_paddle.numpy(), y_np)


class TestSliceApiEager(unittest.TestCase):
    def test_slice_api(self):
        with paddle.fluid.dygraph.guard():
            a = paddle.rand(shape=[4, 5, 6], dtype='float32')
            a.stop_gradient = False
            axes = [0, 1, 2]
            starts = [-3, 0, 2]
            ends = [3, 2, 4]
            a_1 = paddle.slice(a, axes=axes, starts=starts, ends=ends)

            a_2 = paddle.slice(
                a,
                axes=axes,
                starts=paddle.to_tensor(starts),
                ends=paddle.to_tensor(ends),
            )
            np.testing.assert_array_equal(a_1.numpy(), a_2.numpy())
            a_1.backward()
            grad_truth = paddle.zeros_like(a)
            grad_truth[-3:3, 0:2, 2:4] = 1
            np.testing.assert_array_equal(grad_truth, a.gradient())

            np.testing.assert_allclose(
                a_1.numpy(), a[-3:3, 0:2, 2:4], rtol=1e-05
            )


class TestSliceApiWithLoDTensorArray(unittest.TestCase):
    def setUp(self):
        self.shape = (3, 4)
        self.data = np.random.random(size=self.shape).astype('float32')
        self.idx = 0
        self.start = 0
        self.end = 2
        self.axis = 1

        self.place = (
            fluid.CUDAPlace(0)
            if fluid.is_compiled_with_cuda()
            else fluid.CPUPlace()
        )
        self.exe = fluid.Executor(self.place)

    def set_program_and_run(self, main_program, case_num):
        with fluid.program_guard(main_program):
            x = [
                fluid.data(name='x0', shape=self.shape, dtype="float32"),
                fluid.data(name='x1', shape=self.shape, dtype="float32"),
                fluid.data(name='x2', shape=self.shape, dtype="float32"),
            ]

            for each_x in x:
                each_x.stop_gradient = False

            arr = paddle.tensor.create_array(dtype="float32")
            for i in range(3):
                idx = paddle.tensor.array_length(arr)
                arr = paddle.tensor.array_write(x=x[i], i=idx, array=arr)

            if case_num == 1:
                self.sliced_arr = output = arr[0]

            elif case_num == 2:
                end = (
                    paddle.tensor.array_length(arr) - 1
                )  # dtype of end is int64
                self.sliced_arr = slice_arr = arr[self.start : end]
                output, _ = tensor_array_to_tensor(
                    slice_arr, axis=self.axis, use_stack=True
                )
            elif case_num == 3:
                value_int64 = paddle.tensor.fill_constant(
                    [1], "int64", 2147483648
                )
                self.sliced_arr = slice_arr = arr[self.start : value_int64]
                output, _ = tensor_array_to_tensor(
                    slice_arr, axis=self.axis, use_stack=True
                )

            loss = paddle.sum(output)
            fluid.backward.append_backward(loss)
            g_vars = list(
                map(
                    main_program.global_block().var,
                    [each_x.name + "@GRAD" for each_x in x],
                )
            )
            self.out, self.g_x0, self.g_x1, self.g_x2 = self.exe.run(
                main_program,
                feed={'x0': self.data, 'x1': self.data, 'x2': self.data},
                fetch_list=[output] + g_vars,
            )

    def test_case_1(self):
        main_program = fluid.Program()
        self.set_program_and_run(main_program, 1)

        self.assertTrue(self.sliced_arr.type == core.VarDesc.VarType.LOD_TENSOR)
        self.assertEqual(self.sliced_arr.shape, self.shape)
        np.testing.assert_array_equal(self.out, self.data)
        np.testing.assert_array_equal(self.g_x0, np.ones_like(self.data))
        np.testing.assert_array_equal(self.g_x1, np.zeros_like(self.data))
        np.testing.assert_array_equal(self.g_x2, np.zeros_like(self.data))

    def test_case_2(self):
        main_program = fluid.Program()
        self.set_program_and_run(main_program, 2)

        self.assertTrue(
            self.sliced_arr.type == core.VarDesc.VarType.LOD_TENSOR_ARRAY
        )
        self.assertEqual(self.sliced_arr.shape, self.shape)
        np.testing.assert_array_equal(
            self.out, np.stack([self.data, self.data], axis=self.axis)
        )
        np.testing.assert_array_equal(self.g_x0, np.ones_like(self.data))
        np.testing.assert_array_equal(self.g_x1, np.ones_like(self.data))
        np.testing.assert_array_equal(self.g_x2, np.zeros_like(self.data))

    def test_case_3(self):
        main_program = fluid.Program()
        self.set_program_and_run(main_program, 3)

        self.assertTrue(
            self.sliced_arr.type == core.VarDesc.VarType.LOD_TENSOR_ARRAY
        )
        self.assertEqual(self.sliced_arr.shape, self.shape)
        np.testing.assert_array_equal(
            self.out,
            np.stack([self.data, self.data, self.data], axis=self.axis),
        )
        np.testing.assert_array_equal(self.g_x0, np.ones_like(self.data))
        np.testing.assert_array_equal(self.g_x1, np.ones_like(self.data))
        np.testing.assert_array_equal(self.g_x2, np.ones_like(self.data))


class TestImperativeVarBaseGetItem(unittest.TestCase):
    def test_getitem_with_long(self):
        with fluid.dygraph.guard():
            data = np.random.random((2, 80, 16128)).astype('float32')
            var = fluid.dygraph.to_variable(data)
            sliced = var[:, 10:, : var.shape[1]]  # var.shape[1] is 80L here
            self.assertEqual(sliced.shape, [2, 70, 80])

            sliced = var[:, var.shape[0] :, var.shape[0] : var.shape[1]]
            self.assertEqual(sliced.shape, [2, 78, 78])

    def test_getitem_with_float(self):
        def test_float_in_slice_item():
            with fluid.dygraph.guard():
                data = np.random.random((2, 80, 16128)).astype('float32')
                var = fluid.dygraph.to_variable(data)
                sliced = var[:, 1.1:, : var.shape[1]]

        self.assertRaises(Exception, test_float_in_slice_item)

        def test_float_in_index():
            with fluid.dygraph.guard():
                data = np.random.random((2, 80, 16128)).astype('float32')
                var = fluid.dygraph.to_variable(data)
                sliced = var[1.1]

        self.assertRaises(Exception, test_float_in_index)


class TestInferShape(unittest.TestCase):
    def test(self):
        x = paddle.ones(shape=[3, 4, 5])
        x.desc.set_shape([3, -1, 5])
        self.assertEqual(x.shape, (3, -1, 5))

        out0 = paddle.slice(x, axes=[1], starts=[0], ends=[3])
        self.assertEqual(out0.shape, (3, -1, 5))

    def test_axis_less_than_zero(self):
        # Using paddle.disable_static will make other unittests fail.
        with fluid.dygraph.guard():
            x_arr = np.arange(0, 24, dtype=np.float32).reshape([2, 3, 4])
            x = paddle.to_tensor(x_arr)

            pp_slice = paddle.slice(
                x,
                [
                    100,
                ],
                [0],
                [1],
            )
            np_slice = x_arr[:, :, 0:1]
            np.testing.assert_array_equal(pp_slice, np_slice)

            pp_slice = paddle.slice(x, (-100,), [0], [1])
            np_slice = x_arr[0:1]
            np.testing.assert_array_equal(pp_slice, np_slice)

            x_arr = np.array([], dtype=np.float32)
            x = paddle.to_tensor(np.reshape(x_arr, (0, 0, 0)))

            starts = paddle.to_tensor(
                np.reshape(np.array([], dtype=np.int32), (0,))
            )
            ends = paddle.to_tensor(
                np.reshape(np.array([], dtype=np.int32), (0,))
            )

            with self.assertRaises(ValueError):
                paddle.slice(x, [-1000000], starts, ends)

            with self.assertRaises(ValueError):
                paddle.slice(x, [1000000], starts, ends)

            with self.assertRaises(ValueError):
                paddle.slice(x, [], starts, ends)

            with self.assertRaises(ValueError):
                paddle.slice(x, 0, starts, ends)


class TestSliceOpError(unittest.TestCase):
    def test_dismatch_shape(self):
        with fluid.dygraph.guard():
            with self.assertRaises(ValueError):
                array = np.array([], dtype=np.float32)
                x = paddle.to_tensor(np.reshape(array, [0]), dtype='float32')
                paddle.slice(x, axes=[0], starts=[], ends=[])

            with self.assertRaises(ValueError):
                array = np.array([], dtype=np.float32)
                x = paddle.to_tensor(np.reshape(array, [0]), dtype='float32')
                paddle.slice(x, axes=[0], starts=[0], ends=[])

            # if shape match, pass
            array = np.array([], dtype=np.float32)
            x = paddle.to_tensor(np.reshape(array, [0]), dtype='float32')
            out = paddle.slice(x, axes=[0], starts=[0], ends=[0])
            self.assertEqual(out.numel(), 0)
            # self.assertEqual(out.shape)


@unittest.skipIf(
    not core.is_compiled_with_cuda(), "core is not compiled with CUDA"
)
class TestImperativeCUDAPinnedInput(unittest.TestCase):
    def test_input_cuda_pinned_var(self):
        with fluid.dygraph.guard():
            data = np.random.random((2, 80, 16128)).astype('float32')
            var = core.eager.Tensor(
                value=data,
                name='',
                persistable=False,
                place=fluid.CUDAPinnedPlace(),
                zero_copy=False,
            )
            sliced = var[:, 10:, : var.shape[1]]
            self.assertEqual(sliced.shape, [2, 70, 80])


class TestSliceDoubleGradCheck(unittest.TestCase):
    def slice_wrapper(self, x):
        return paddle.slice(
            x[0], axes=[0, 1, 2], starts=[-3, 0, 2], ends=[3, 2, 4]
        )

    @prog_scope()
    def func(self, place):
        # the shape of input variable should be clearly specified, not inlcude -1.
        eps = 0.005
        dtype = np.float32

        data = paddle.static.data('data', [4, 5, 6], dtype)
        data.persistable = True
        out = paddle.slice(
            data, axes=[0, 1, 2], starts=[-3, 0, 2], ends=[3, 2, 4]
        )
        data_arr = np.random.uniform(-1, 1, data.shape).astype(dtype)

        gradient_checker.double_grad_check(
            [data], out, x_init=[data_arr], place=place, eps=eps
        )
        gradient_checker.double_grad_check_for_dygraph(
            self.slice_wrapper, [data], out, x_init=[data_arr], place=place
        )

    def test_grad(self):
        paddle.enable_static()
        places = [fluid.CPUPlace()]
        if core.is_compiled_with_cuda():
            places.append(fluid.CUDAPlace(0))
        for p in places:
            self.func(p)


class TestSliceTripleGradCheck(unittest.TestCase):
    def slice_wrapper(self, x):
        return paddle.slice(
            x[0], axes=[0, 1, 2], starts=[-3, 0, 2], ends=[3, 2, 4]
        )

    @prog_scope()
    def func(self, place):
        # the shape of input variable should be clearly specified, not inlcude -1.
        eps = 0.005
        dtype = np.float32

        data = paddle.static.data('data', [4, 5, 6], dtype)
        data.persistable = True
        out = paddle.slice(
            data, axes=[0, 1, 2], starts=[-3, 0, 2], ends=[3, 2, 4]
        )
        data_arr = np.random.uniform(-1, 1, data.shape).astype(dtype)

        gradient_checker.triple_grad_check(
            [data], out, x_init=[data_arr], place=place, eps=eps
        )
        gradient_checker.triple_grad_check_for_dygraph(
            self.slice_wrapper, [data], out, x_init=[data_arr], place=place
        )

    def test_grad(self):
        paddle.enable_static()
        places = [fluid.CPUPlace()]
        if core.is_compiled_with_cuda():
            places.append(fluid.CUDAPlace(0))
        for p in places:
            self.func(p)


if __name__ == '__main__':
    paddle.enable_static()
    unittest.main()