test_nn.py

import math
import random
import string
import unittest
import itertools
import contextlib
import warnings
import pickle
from copy import deepcopy
from itertools import repeat, product
from functools import wraps, reduce
from operator import mul
from collections import OrderedDict
import threading

import torch
from torch._six import inf, nan
import torch.backends.cudnn as cudnn
import torch.nn as nn
import torch.nn.functional as F
import torch.nn.parallel as dp
import torch.nn.init as init
import torch.nn.utils.rnn as rnn_utils
from torch.nn.utils import clip_grad_norm_, clip_grad_value_
from torch.nn.utils import parameters_to_vector, vector_to_parameters
from torch.autograd import Variable, gradcheck
from torch.autograd.gradcheck import gradgradcheck
from torch.nn import Parameter
from torch.nn.parallel._functions import Broadcast
from common_utils import freeze_rng_state, run_tests, TestCase, skipIfNoLapack, skipIfRocm, \
    TEST_NUMPY, TEST_SCIPY, download_file, PY3, PY34, to_gpu, \
    get_function_arglist, load_tests
from common_cuda import TEST_CUDA, TEST_MULTIGPU, TEST_CUDNN, TEST_CUDNN_VERSION
from common_nn import NNTestCase, ModuleTest, CriterionTest, TestBase, \
    module_tests, criterion_tests, loss_reference_fns, get_reduction, \
    get_weight, smoothl1loss_reference, kldivloss_reference, \
    ctcloss_reference, new_module_tests

from torch.nn import MultiheadAttention

# load_tests from common_utils is used to automatically filter tests for
# sharding on sandcastle. This line silences flake warnings
load_tests = load_tests

if TEST_SCIPY:
    from scipy import stats
    import scipy.ndimage

if TEST_NUMPY:
    import numpy as np

ALL_TENSORTYPES = [torch.float,
                   torch.double,
                   torch.half]

NO_HALF_TENSORTYPES = [torch.float,
                       torch.double]

DOUBLE_TENSORTYPES = [torch.double]

dtype2prec = {torch.float: 1e-5,
              torch.double: 1e-5,
              torch.half: 1e-2}


# WARNING: If you add a new top-level test case to this file, you MUST
# update test/run_test.py to list it, otherwise it will NOT be run in
# CI.


# Used to run the same test with different tensor types
def repeat_test_for_types(dtypes):
    def repeat_helper(f):
        @wraps(f)
        def call_helper(self, *args):
            for dtype in dtypes:
                if PY34:
                    with TestCase.subTest(self, dtype=dtype):
                        f(self, *args, dtype=dtype)
                else:
                    f(self, *args, dtype=dtype)

        return call_helper
    return repeat_helper


class PackedSequenceTest(TestCase):

    _type_by_name = {
        'torch.DoubleTensor': (torch.DoubleTensor, 'double'),
        'torch.FloatTensor': (torch.FloatTensor, 'float'),
        # We leave out `'torch.HalfTensor': (torch.HalfTensor, 'half'),`
        # because of an error in `pad_packed_sequence`
        # > AttributeError: 'torch.HalfTensor' object has no attribute 'fill_'
        'torch.LongTensor': (torch.LongTensor, 'long'),
        'torch.IntTensor': (torch.IntTensor, 'int'),
        'torch.ShortTensor': (torch.ShortTensor, 'short'),
        'torch.CharTensor': (torch.CharTensor, 'char'),
        'torch.ByteTensor': (torch.ByteTensor, 'byte'),
    }

    def __init__(self, *args, **kwargs):
        super(PackedSequenceTest, self).__init__(*args, **kwargs)
        self.batch_size = 5
        self.max_length = 6

    def _ordered_sequence(self, tensor_type):
        """Create ordered list of random sequences"""
        seqs = [tensor_type(random.randint(1, self.max_length))
                for _ in range(self.batch_size)]
        seqs = [s.random_(-128, 128) for s in seqs]
        ordered = sorted(seqs, key=len, reverse=True)
        return ordered

    def _padded_sequence(self, tensor_type):
        """Create Tensor of random padded sequences"""
        ordered = self._ordered_sequence(tensor_type)
        lengths = list(map(len, ordered))
        padded_tensor = rnn_utils.pad_sequence(ordered)
        return padded_tensor, lengths

    def test_type_casts(self):
        """Test type casting of `PackedSequence` against type casting of tensor"""
        for _, (input_type, _) in self._type_by_name.items():
            for expected_type_str, (_, cast_str) in self._type_by_name.items():
                for enforce_sorted in [True, False]:
                    padded, lengths = self._padded_sequence(input_type)
                    packed = rnn_utils.pack_padded_sequence(
                        padded, lengths, enforce_sorted=enforce_sorted)
                    # Apply cast to `PackedSequence` instance and unpack
                    masked = getattr(packed, cast_str)()
                    unpacked, lengths_out = rnn_utils.pad_packed_sequence(masked)
                    self.assertEqual(unpacked.type(), expected_type_str)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_cuda_mask(self):
        for enforce_sorted in [True, False]:
            tensor_type = torch.FloatTensor
            cuda_type_str = 'torch.cuda.FloatTensor'
            padded, lengths = self._padded_sequence(tensor_type)
            packed = rnn_utils.pack_padded_sequence(
                padded, lengths, enforce_sorted=enforce_sorted)
            self.assertFalse(packed.is_cuda)
            packed = packed.cuda()
            self.assertTrue(packed.is_cuda)
            unpacked, _ = rnn_utils.pad_packed_sequence(packed)
            self.assertEqual(unpacked.type(), cuda_type_str)

    def test_wrong_order(self):
        a = torch.ones(25, 300)
        b = torch.ones(22, 300)
        b_a = rnn_utils.pad_sequence([b, a])
        self.assertRaises(
            RuntimeError,
            lambda: rnn_utils.pack_padded_sequence(b_a, [22, 25], enforce_sorted=True))

    def test_total_length(self):
        padded, lengths = self._padded_sequence(torch.FloatTensor)
        max_length = max(lengths)
        packed = rnn_utils.pack_padded_sequence(padded, lengths)
        # test ValueError if total_length < max_length
        for total_length in (-1, 0, max_length - 1):
            for batch_first in (True, False):
                def err_fn():
                    rnn_utils.pad_packed_sequence(packed, batch_first=batch_first,
                                                  total_length=total_length)
            self.assertRaisesRegex(ValueError,
                                   r'Expected total_length to be at least the '
                                   r'length of the longest sequence in input',
                                   err_fn)
        # test that pad_packed_sequence returns results of correct length
        for batch_first in (True, False):
            no_extra_pad, _ = rnn_utils.pad_packed_sequence(packed, batch_first=batch_first)
            for total_length_delta in (0, 1, 8):
                total_length = max_length + total_length_delta
                unpacked, lengths_out = rnn_utils.pad_packed_sequence(packed, batch_first=batch_first,
                                                                      total_length=total_length)
                self.assertEqual(lengths, lengths_out)
                self.assertEqual(unpacked.size(1 if batch_first else 0), total_length)
                if total_length_delta == 0:
                    ref_output = no_extra_pad
                elif batch_first:
                    extra_pad = no_extra_pad.new_zeros(self.batch_size, total_length_delta)
                    ref_output = torch.cat([no_extra_pad, extra_pad], 1)
                else:
                    extra_pad = no_extra_pad.new_zeros(total_length_delta, self.batch_size)
                    ref_output = torch.cat([no_extra_pad, extra_pad], 0)
                self.assertEqual(unpacked, ref_output)

    def test_to(self):
        for enforce_sorted in (True, False):
            padded, lengths = self._padded_sequence(torch.IntTensor)
            a = rnn_utils.pack_padded_sequence(
                padded, lengths, enforce_sorted=enforce_sorted).cpu()

            self.assertIs(a, a.to('cpu'))
            self.assertIs(a, a.to('cpu', dtype=torch.int32))
            self.assertEqual(a.long(), a.to(torch.int64))

            if torch.cuda.is_available():
                for cuda in ['cuda', 'cuda:0' if torch.cuda.device_count() == 1 else 'cuda:1']:
                    b = a.cuda(device=cuda)
                    self.assertIs(b, b.to(cuda))
                    self.assertEqual(a, b.to('cpu'))
                    self.assertEqual(b, a.to(cuda))
                    self.assertEqual(a, b.to('cpu', dtype=torch.int32))
                    self.assertIs(b, b.to(dtype=torch.int32))
                    self.assertEqual(b.long(), b.to(dtype=torch.int64))


def default_tensor_type(type):
    type_str = torch.typename(type)

    def decorator(fn):
        @wraps(fn)
        def wrapper(*args, **kwargs):
            old_type = torch.Tensor().type()
            torch.set_default_tensor_type(type_str)
            try:
                return fn(*args, **kwargs)
            finally:
                torch.set_default_tensor_type(old_type)

        return wrapper

    return decorator


def _assertGradAndGradgradChecks(test_case, apply_fn, inputs):
    # call assert function rather than returning a bool since it's nicer
    # if we get whether this failed on the gradcheck or the gradgradcheck.
    test_case.assertTrue(gradcheck(apply_fn, inputs))
    test_case.assertTrue(gradgradcheck(apply_fn, inputs))


class InputVariableMixin(object):
    def _get_input(self):
        input = TestBase._get_input(self, False)

        def map_variables(i):
            if isinstance(i, torch.Tensor):
                if i.is_floating_point():
                    i.requires_grad = True
                return i
            else:
                return type(i)(map_variables(elem) for elem in i)

        return map_variables(input)


class NewModuleTest(InputVariableMixin, ModuleTest):
    def __init__(self, *args, **kwargs):
        super(NewModuleTest, self).__init__(*args, **kwargs)
        self.cudnn = kwargs.get('cudnn', False)
        self.check_inplace = kwargs.get('check_inplace', False)
        self.check_gradgrad = kwargs.get('check_gradgrad', True)
        self.skip_double = kwargs.get('skip_double', False)

    def _do_test(self, test_case, module, input):
        test_case.check_jacobian(module, input, self.jacobian_input)

        if self.check_gradgrad:
            # could probably unify check_jacobian above with this.
            params = tuple(x for x in module.parameters())
            _assertGradAndGradgradChecks(test_case,
                                         lambda x, *args, **kw: test_case._forward(module, x), (input,) + params)

        # check if module can be printed
        module.__repr__()

        if self.check_inplace:
            # check if the inplace variant of the module gives the same result
            # as the out-of-place

            module_ip = self.constructor(*self.constructor_args, inplace=True)

            input_version = input._version
            with freeze_rng_state():
                output = module(input)
            test_case.assertEqual(input._version, input_version)

            input_ip = deepcopy(input)
            input_ip_clone = input_ip.clone()
            with freeze_rng_state():
                output_ip = module_ip(input_ip_clone)
            test_case.assertNotEqual(input_ip_clone._version, input_version)
            test_case.assertEqual(output, output_ip)
            grad = output.data.clone().normal_()
            input.grad.data.zero_()
            output.backward(grad)
            output_ip.backward(grad)
            test_case.assertEqual(input.grad, input_ip.grad)

        if isinstance(input, torch.LongTensor) and TEST_CUDA:
            # check that cuda() moves module parameters to correct GPU device,
            # and that float() casts parameters correctly

            input = input.cuda()
            module.float().cuda()
            module(input)
            for p in module.parameters():
                test_case.assertIsInstance(p, torch.cuda.FloatTensor)
                test_case.assertEqual(p.get_device(), 0)

            if torch.cuda.device_count() > 1:
                input = input.cuda(1)
                module.cuda(1)
                with torch.cuda.device(1):
                    module(input)
                for p in module.parameters():
                    test_case.assertIsInstance(p, torch.cuda.FloatTensor)
                    test_case.assertEqual(p.get_device(), 1)
        else:
            # check that float()/double() casters work correctly

            # to float
            if not isinstance(input, torch.LongTensor):
                input = input.float()
            module.float()
            module(input)
            for p in module.parameters():
                test_case.assertIsInstance(p, torch.FloatTensor)

            # and back to double
            if not isinstance(input, torch.LongTensor):
                input = input.double()
            module.double()
            module(input)
            for p in module.parameters():
                test_case.assertIsInstance(p, torch.DoubleTensor)

            if TEST_CUDA and self.should_test_cuda:
                # check that cuda() moves module parameters to correct GPU device,
                # and that float() casts parameters correctly

                # to GPU0
                input = input.float().cuda()
                module.float().cuda()
                module(input)
                for p in module.parameters():
                    test_case.assertIsInstance(p, torch.cuda.FloatTensor)
                    test_case.assertEqual(p.get_device(), 0)

                # to CPU
                input = input.cpu()
                module.cpu()
                module(input)
                for p in module.parameters():
                    test_case.assertIsInstance(p, torch.FloatTensor)

                # back to GPU0
                input = input.cuda()
                module.cuda()
                module(input)
                for p in module.parameters():
                    test_case.assertIsInstance(p, torch.cuda.FloatTensor)
                    test_case.assertEqual(p.get_device(), 0)

                # test that forwards of module runs correctly without cuDNN
                if self.cudnn:
                    with torch.backends.cudnn.flags(enabled=False):
                        module(input)
                        for p in module.parameters():
                            test_case.assertIsInstance(p, torch.cuda.FloatTensor)
                            test_case.assertEqual(p.get_device(), 0)

                if torch.cuda.device_count() >= 2:
                    # test cross-GPU transfer works
                    # to GPU1
                    input = input.cuda(1)
                    module.cuda(1)
                    with torch.cuda.device(1):
                        module(input)
                    for p in module.parameters():
                        test_case.assertIsInstance(p, torch.cuda.FloatTensor)
                        test_case.assertEqual(p.get_device(), 1)

                if not self.skip_double:
                    # test double()
                    input = input.double().cuda()
                    module.double().cuda()
                    module(input)
                    for p in module.parameters():
                        test_case.assertIsInstance(p, torch.cuda.DoubleTensor)
                        test_case.assertEqual(p.get_device(), 0)

                # test half()
                input = input.half().cuda()
                module.half().cuda()
                module(input)
                for p in module.parameters():
                    test_case.assertIsInstance(p, torch.cuda.HalfTensor)
                    test_case.assertEqual(p.get_device(), 0)

    def _get_target(self):
        return self._get_arg('target', False)

    @property
    def constructor_args(self):
        return self._get_arg('constructor_args', False)


class NewCriterionTest(InputVariableMixin, CriterionTest):
    # TODO: check that criterions don't ignore grad_output

    def __init__(self, *args, **kwargs):
        super(NewCriterionTest, self).__init__(*args, **kwargs)
        self.check_gradgrad = kwargs.get('check_gradgrad', True)
        self.check_half = kwargs.get('check_half', True)
        self.convert_target = kwargs.get('convert_target', True)

    def _do_extra_tests(self, test_case, module, input, target):
        if not self.check_gradgrad:
            return

        test_case.assertFalse(target.requires_grad)

        params = tuple(x for x in module.parameters())
        if not isinstance(input, tuple):
            inputs = (input,) + params

            def apply_fn(input, *params):
                return module(input, target)
        else:
            inputs = input + params

            def apply_fn(input1, input2, *params):
                return module(input1, input2, target)

        # TODO: we don't pass `target` as part of inputs because we don't
        # currently compute the gradient w.r.t. target for loss functions.
        gradcheck(apply_fn, inputs)
        gradgradcheck(apply_fn, inputs)

    def test_cuda(self, test_case, dtype=None, extra_args=None):
        def convert_dtype(obj, dtype, requires_grad=False):
            if isinstance(obj, torch.Tensor):
                return obj.detach().to(dtype=dtype).requires_grad_(requires_grad)
            elif isinstance(obj, torch.Tensor):
                return obj.to(dtype)
            elif isinstance(obj, tuple):
                return tuple(convert_dtype(o, dtype, requires_grad) for o in obj)
            else:
                return obj

        if not TEST_CUDA or not self.should_test_cuda:
            raise unittest.SkipTest('Excluded from CUDA tests')
        try:
            cpu_input = self._get_input()
            cpu_target = self._get_target()
            cpu_module = self.constructor(*self.constructor_args)
            gpu_module = self.constructor(*self.constructor_args)

            # Convert input, target and module parameters to dtype
            if dtype is not None:
                cpu_input = convert_dtype(cpu_input, dtype, True)
                # NLLLoss requires target to be LongTensor
                if not isinstance(cpu_target, torch.LongTensor) and self.convert_target:
                    cpu_target = convert_dtype(cpu_target, dtype)
                cpu_module.type(dtype)
                gpu_module.type(dtype)

            # GPU setup
            gpu_input = to_gpu(cpu_input)
            gpu_target = to_gpu(cpu_target)
            gpu_module.cuda()

            # torch.HalfTensor doesn't support most operations, converting back to default
            if dtype == torch.half:
                cpu_input = self._get_input()
                cpu_target = self._get_target()
                # Loss modules with weights require consistent input/module weight types
                cpu_module = self.constructor(*self.constructor_args)

            cpu_output = test_case._forward_criterion(cpu_module, cpu_input, cpu_target, extra_args=extra_args)
            gpu_output = test_case._forward_criterion(gpu_module, gpu_input, gpu_target, extra_args=extra_args)
            # dtype can be None, so set precision in this way instead of a precision map
            test_case.assertEqual(cpu_output, gpu_output, 1e-1 if dtype == torch.half else 4e-4)

            cpu_gradInput = test_case._backward_criterion(cpu_module, cpu_input, cpu_target, extra_args=extra_args)
            gpu_gradInput = test_case._backward_criterion(gpu_module, gpu_input, gpu_target, extra_args=extra_args)
            test_case.assertEqual(cpu_gradInput, gpu_gradInput, 1e-1 if dtype == torch.half else 4e-4)
        except NotImplementedError:
            pass

    def _get_target(self):
        return self._get_arg('target', False)

    @property
    def constructor_args(self):
        return self._get_arg('constructor_args', False)

    @property
    def extra_args(self):
        return self._get_arg('extra_args', False)


class TestNN(NNTestCase):
    _do_cuda_memory_leak_check = True

    def _forward(self, module, input):
        with freeze_rng_state():
            return module(input)

    def _backward(self, module, input, output, grad_output, create_graph=False):
        output.backward(grad_output, retain_graph=True, create_graph=create_graph)
        if input.grad is None:
            return None
        return input.grad.data

    def _forward_criterion(self, criterion, input, target, extra_args=None):
        if extra_args is None:
            extra_args = tuple()
        if isinstance(input, tuple):
            args = input + (target,) + extra_args
            output = criterion(*args)
        else:
            output = criterion(input, target, *extra_args)
        return output

    def _backward_criterion(self, criterion, input, target, gradOutput=None, extra_args=None):
        if extra_args is None:
            extra_args = tuple()
        input_tuple = input if isinstance(input, tuple) else (input,)
        for i in input_tuple:
            if i.grad is not None:
                i.grad.data.zero_()
        args = input_tuple + (target,) + extra_args
        if gradOutput is None:
            gradOutput = torch.ones(())
        criterion(*args).backward(gradOutput.type_as(input_tuple[0]))
        if isinstance(input, tuple):
            return tuple(map(lambda i: i.grad.data, input))
        else:
            return input.grad.data

    def _zero_grad_parameters(self, module):
        for p in module.parameters():
            if p.grad is not None:
                with torch.no_grad():
                    p.grad.zero_()
                p.grad.detach_()

    def _get_parameters(self, module):
        params = []
        d_params = []
        for p in module.parameters():
            params.append(p)
            d_params.append(p.grad)
        return params, d_params

    def _create_basic_net(self):
        class Layer(nn.Module):
            def __init__(self):
                super(Layer, self).__init__()
                self.layer_dummy_param = Parameter(torch.Tensor(3, 5))
                self.register_buffer('layer_dummy_buf', torch.zeros(1, 3, 3, 7))

        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.l1 = Layer()
                self.dummy_param = Parameter(torch.Tensor(3, 5))
                self.register_buffer('dummy_buf', torch.zeros(7, 3, 3, 1))

        l = Layer()
        n = Net()
        s = nn.Sequential(n, n)

        return l, n, s

    def test_module_backcompat(self):
        from torch.serialization import SourceChangeWarning
        path = download_file('https://download.pytorch.org/test_data/linear.pt')
        with warnings.catch_warnings():
            warnings.simplefilter('ignore', SourceChangeWarning)
            m = torch.load(path)
        input = torch.randn(2, 3, dtype=torch.float)
        self.assertEqual(m(input).size(), (2, 5))

    def test_share_memory(self):
        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.p = nn.Parameter(torch.eye(5))
                self.par = nn.ParameterList()
                self.par.append(nn.Parameter(torch.randn(10)))

            def forward(self, inp):
                # NB: dead code
                return inp.clone()

        net = Net()
        for p in net.parameters():
            self.assertFalse(p.storage().is_shared())
        for b in net.buffers():
            self.assertFalse(b.storage().is_shared())
        net.share_memory()
        for p in net.parameters():
            self.assertTrue(p.storage().is_shared())
        for b in net.buffers():
            self.assertTrue(b.storage().is_shared())

    def test_hooks(self):
        module = nn.Sigmoid()
        input = torch.ones(5, 5, requires_grad=True)

        counter = {
            'forwards': 0,
            'backwards': 0
        }

        def fw_hook(inc, h_module, input, output):
            self.assertIsInstance(input, tuple)
            self.assertTrue(isinstance(output, torch.Tensor))
            self.assertTrue(h_module is module)
            self.assertEqual(input[0].data, torch.ones(5, 5))
            self.assertEqual(output.data, torch.Tensor(5, 5).fill_(1 / (1 + 1 / math.e)))
            counter['forwards'] += inc

        def bw_hook(inc, h_module, grad_input, grad_output):
            self.assertIsInstance(grad_input, tuple)
            self.assertIsInstance(grad_output, tuple)
            self.assertTrue(h_module is module)
            self.assertEqual(grad_output[0].data, torch.ones(5, 5) * 2)
            counter['backwards'] += inc

        test_fwd = module.register_forward_hook(lambda *args: fw_hook(1, *args))

        module(input)
        module(input)
        self.assertEqual(counter['forwards'], 2)
        self.assertEqual(counter['backwards'], 0)

        test_bwd = module.register_backward_hook(
            lambda *args: bw_hook(1, *args))

        output = module(input)
        self.assertEqual(counter['forwards'], 3)
        self.assertEqual(counter['backwards'], 0)

        output.backward(torch.ones(5, 5) * 2, retain_graph=True)
        self.assertEqual(counter['forwards'], 3)
        self.assertEqual(counter['backwards'], 1)

        output.backward(torch.ones(5, 5) * 2, retain_graph=True)
        self.assertEqual(counter['forwards'], 3)
        self.assertEqual(counter['backwards'], 2)

        test2_fwd = module.register_forward_hook(lambda *args: fw_hook(2, *args))

        output = module(input)
        self.assertEqual(counter['forwards'], 6)
        self.assertEqual(counter['backwards'], 2)

        test2_bwd = module.register_backward_hook(lambda *args: bw_hook(2, *args))

        module(input).backward(torch.ones(5, 5) * 2)
        self.assertEqual(counter['forwards'], 9)
        self.assertEqual(counter['backwards'], 5)

        test2_bwd.remove()

        module(input).backward(torch.ones(5, 5) * 2)
        self.assertEqual(counter['forwards'], 12)
        self.assertEqual(counter['backwards'], 6)

        test2_fwd.remove()

        module(input).backward(torch.ones(5, 5) * 2)
        self.assertEqual(counter['forwards'], 13)
        self.assertEqual(counter['backwards'], 7)

        test_fwd.remove()
        test_bwd.remove()

    def test_hook_cpp(self):
        counter = [0]
        bn = nn.BatchNorm1d(5)

        def hook(module, grad_inputs, grad_outputs):
            counter[0] += 1
            self.assertEqual(len(grad_inputs), 3)
            self.assertEqual(len(grad_outputs), 1)
            self.assertEqual(module, bn)

        bn.register_backward_hook(hook)
        output = bn(torch.randn(5, 5, requires_grad=True))
        output.sum().backward()

    def test_hook_fail(self):
        module = nn.Sigmoid()
        input = torch.randn(5, 5, requires_grad=True)

        def fw_fail1(self, input, output):
            return output

        def fw_fail2(self, input, output):
            return input

        def bw_fail1(self, grad_input, grad_output):
            return grad_input[:-1]

        def bw_fail2(self, grad_input, grad_output):
            return grad_input + (torch.randn(2, 2),)

        with module.register_forward_hook(fw_fail1):
            with self.assertRaises(RuntimeError) as err:
                module(input)
            self.assertIn("fw_fail", err.exception.args[0])
            self.assertIn("didn't return None", err.exception.args[0])

        with module.register_forward_hook(fw_fail2):
            with self.assertRaises(RuntimeError) as err:
                module(input)
            self.assertIn("fw_fail2", err.exception.args[0])
            self.assertIn("didn't return None", err.exception.args[0])

        with module.register_backward_hook(bw_fail1):
            with self.assertRaises(RuntimeError) as err:
                module(input).sum().backward()
            self.assertIn("bw_fail", err.exception.args[0])
            self.assertIn("got 0, but expected 1", err.exception.args[0])

        with module.register_backward_hook(bw_fail2):
            with self.assertRaises(RuntimeError) as err:
                module(input).sum().backward()
            self.assertIn("bw_fail2", err.exception.args[0])
            self.assertIn("got 2, but expected 1", err.exception.args[0])

    def test_hook_writeable(self):
        module = nn.Linear(5, 5)
        input = torch.randn(5, 5, requires_grad=True)

        def bw_hook(module, grad_input, grad_output):
            for grad in grad_input:
                self.assertTrue(isinstance(grad, torch.Tensor))
            for grad in grad_output:
                self.assertTrue(isinstance(grad, torch.Tensor))
            return tuple(gi * 2 for gi in grad_input)

        module.register_backward_hook(bw_hook)
        module(input).backward(torch.ones(5, 5))
        expected_grad = torch.ones(5, 5).mm(module.weight.data) * 2
        self.assertEqual(input.grad.data, expected_grad)

    def test_to(self):
        m = nn.Linear(3, 5)
        self.assertIs(m, m.to('cpu'))
        self.assertIs(m, m.to('cpu', dtype=torch.float32))
        self.assertEqual(m.double(), m.to(torch.float64))
        self.assertRaises(RuntimeError, lambda: m.to('cpu', copy=True))

        if torch.cuda.is_available():
            for cuda in ['cuda', 'cuda:0' if torch.cuda.device_count() == 1 else 'cuda:1']:
                m2 = m.cuda(device=cuda)
                self.assertIs(m2, m2.to(cuda))
                self.assertEqual(m, m2.to('cpu'))
                self.assertEqual(m2, m.to(cuda))
                self.assertIs(m2, m2.to(dtype=torch.float32))
                self.assertEqual(m2.double(), m2.to(dtype=torch.float64))

    def test_zero_grad(self):
        i = torch.randn(2, 5, requires_grad=True)
        module = nn.Linear(5, 5)
        for p in module.parameters():
            p.requires_grad = False
        module.zero_grad()

        module.weight.requires_grad = True
        module.zero_grad()
        self.assertIsNone(module.weight.grad)  # uninitialized grad

        module(i).sum().backward()
        self.assertIsNotNone(module.weight.grad)
        self.assertGreater(module.weight.grad.data.abs().sum(), 0)
        module.zero_grad()
        self.assertEqual(module.weight.grad.data, module.weight.data.clone().zero_())

        module.bias.requires_grad = True
        module.zero_grad()
        self.assertIsNotNone(module.weight.grad)
        self.assertIsNone(module.bias.grad)
        module(i).sum().backward()
        self.assertIsNotNone(module.weight.grad)
        self.assertIsNotNone(module.bias.grad)
        self.assertGreater(module.weight.grad.data.abs().sum(), 0)
        self.assertGreater(module.bias.grad.data.abs().sum(), 0)
        module.zero_grad()
        self.assertEqual(module.weight.grad.data, module.weight.data.clone().zero_())
        self.assertEqual(module.bias.grad.data, module.bias.data.clone().zero_())

    def test_no_grad(self):
        module = nn.Conv2d(2, 5, kernel_size=3, padding=1)
        input = torch.randn(1, 2, 10, 10)
        x = input
        y = input.clone()

        output = module(x)
        self.assertTrue(output.requires_grad)
        output.backward(torch.ones(1, 5, 10, 10))

        with torch.no_grad():
            output2 = module(y)
            self.assertFalse(output2.requires_grad)
            self.assertRaises(RuntimeError, lambda: output2.backward(torch.ones(1, 5, 10, 10)))

    def test_invalid_conv1d(self):
        module = nn.Conv1d(in_channels=3, out_channels=33, kernel_size=10, stride=1, bias=True)
        input = torch.randn(1, 3, 4)
        with self.assertRaisesRegex(RuntimeError,
                                    r'Calculated padded input size per channel: \(4\). ' +
                                    r'Kernel size: \(10\). Kernel size can\'t be greater than actual input size'):
            module(input)

        # Negative stride check
        module = nn.Conv1d(in_channels=3, out_channels=6, kernel_size=3, stride=-1, bias=True)
        input = torch.randn(1, 3, 4)
        with self.assertRaisesRegex(RuntimeError, 'negative stride is not supported'):
            module(input)

    def test_invalid_conv2d(self):
        module = torch.nn.Conv2d(1, 1, kernel_size=3, dilation=2, stride=2)
        input = torch.empty(1, 1, 4, 4)
        self.assertRaises(RuntimeError, lambda: module(input))

        module = nn.Conv2d(in_channels=3, out_channels=33, kernel_size=10, stride=1, bias=True)
        input = torch.randn(1, 3, 1, 1)
        with self.assertRaisesRegex(RuntimeError,
                                    r'Calculated padded input size per channel: \(1 x 1\). ' +
                                    r'Kernel size: \(10 x 10\). Kernel size can\'t be greater than actual input size'):
            module(input)

        # Negative stride check
        module = nn.Conv2d(in_channels=3, out_channels=6, kernel_size=4, stride=-1, bias=True)
        input = torch.randn(1, 3, 4, 4)
        with self.assertRaisesRegex(RuntimeError, 'negative stride is not supported'):
            module(input)

    def test_invalid_conv3d(self):
        module = torch.nn.Conv3d(1, 1, kernel_size=3, dilation=2, stride=2)
        input = torch.empty(1, 1, 4, 4, 4)
        self.assertRaises(RuntimeError, lambda: module(input))

        # Negative stride check
        module = torch.nn.Conv3d(1, 1, kernel_size=3, stride=-2)
        input = torch.empty(1, 1, 4, 4, 4)
        with self.assertRaisesRegex(RuntimeError, 'negative stride is not supported'):
            module(input)

    def _test_dropout(self, cls, cuda, input):
        p = 0.2
        device = torch.device("cuda") if cuda else torch.device("cpu")
        input = input.to(device).fill_(1 - p)

        module = cls(p)
        input_var = input.clone().requires_grad_()
        output = module(input_var)
        self.assertLess(abs(output.data.mean() - (1 - p)), 0.05)
        output.backward(input)
        self.assertLess(abs(input_var.grad.data.mean() - (1 - p)), 0.05)

        module = cls(p, True)
        input_var = input.clone().requires_grad_()
        output = module(input_var + 0)
        self.assertLess(abs(output.data.mean() - (1 - p)), 0.05)
        output.backward(input)
        self.assertLess(abs(input_var.grad.data.mean() - (1 - p)), 0.05)

        # check eval mode doesn't change anything
        for inplace in [True, False]:
            module = cls(p, inplace).eval()
            self.assertEqual(input, module(input))

        # Check that these don't raise errors
        module.__repr__()
        str(module)

    def _test_alpha_dropout(self, cls, input):
        mean = input.mean()
        std = input.std()

        for p in [0.2, 0.5, 0.8]:
            module = cls(p)
            input_var = input.detach().clone().requires_grad_()
            output = module(input_var)
            # output mean should be close to input mean
            self.assertLess(abs(output.data.mean() - mean), 0.1)
            # output std should be close to input std
            self.assertLess(abs(output.data.std() - std), 0.1)
            output.backward(input)

    def test_parameters_and_named_parameters(self):
        def names(named_parameters):
            return [k for k, _ in named_parameters]

        l, n, s = self._create_basic_net()

        self.assertEqual(len(list(l.parameters())), 1)
        self.assertEqual(
            names(l.named_parameters()),
            ['layer_dummy_param'])

        self.assertEqual(len(list(n.parameters())), 2)
        self.assertEqual(
            names(n.named_parameters()),
            ['dummy_param', 'l1.layer_dummy_param'])

        self.assertEqual(len(list(n.parameters(recurse=False))), 1)
        self.assertEqual(
            names(n.named_parameters(recurse=False)),
            ['dummy_param'])

        self.assertEqual(len(list(s.parameters())), 2)
        self.assertEqual(
            names(s.named_parameters()),
            ['0.dummy_param', '0.l1.layer_dummy_param'])

    def test_buffers_and_named_buffers(self):
        def names(named_buffers):
            return [k for k, _ in named_buffers]

        l, n, s = self._create_basic_net()

        self.assertEqual(len(list(l.buffers())), 1)
        self.assertEqual(
            names(l.named_buffers()),
            ['layer_dummy_buf'])

        self.assertEqual(len(list(n.buffers())), 2)
        self.assertEqual(
            names(n.named_buffers()),
            ['dummy_buf', 'l1.layer_dummy_buf'])

        self.assertEqual(len(list(n.buffers(recurse=False))), 1)
        self.assertEqual(
            names(n.named_buffers(recurse=False)),
            ['dummy_buf'])

        self.assertEqual(len(list(s.buffers())), 2)
        self.assertEqual(
            names(s.named_buffers()),
            ['0.dummy_buf', '0.l1.layer_dummy_buf'])

    def test_call_supports_python_dict_output(self):
        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.l1 = nn.Linear(10, 20)
                self.register_backward_hook(self.hook)
                self.check_backward_hook_flag = False

            def hook(self, module, grad_out, grad_in):
                self.check_backward_hook_flag = True

            def forward(self, inputs):
                return {"output": self.l1(inputs).sum()}

        net = Net()
        model_output = net(torch.randn([5, 10]))
        model_output["output"].backward()
        self.assertTrue(net.check_backward_hook_flag)

    def test_children(self):
        l1 = nn.Linear(2, 2)
        l2 = nn.Linear(2, 2)
        l3 = nn.Linear(2, 2)
        l4 = nn.Linear(2, 2)
        subnet = nn.Sequential(l3, l4)
        s = nn.Sequential(l1, l2, l1, l2, subnet)
        self.assertEqual(list(s.children()), [l1, l2, subnet])

    def test_dir(self):
        linear = nn.Linear(2, 2)
        linear._test_submodule = nn.Linear(2, 2)
        linear._test_parameter = Parameter(torch.Tensor(2, 2))
        linear.register_buffer('_test_buffer', torch.Tensor(2, 2))
        keys = dir(linear)
        self.assertIn('_test_submodule', keys)
        self.assertIn('_test_parameter', keys)
        self.assertIn('_test_buffer', keys)

        for key in keys:
            self.assertTrue(hasattr(linear, key))

    def test_repr(self):
        # no extra information or sub-modules
        empty_sequential = nn.Sequential()
        expected_repr_empty = 'Sequential()'
        self.assertEqual(repr(empty_sequential), expected_repr_empty)

        # one liner extra information
        linear = nn.Linear(1, 1)
        expected_repr_linear = 'Linear(in_features=1, out_features=1, bias=True)'
        self.assertEqual(repr(linear), expected_repr_linear)

        # sub-modules repr
        sequential = nn.Sequential(linear)
        expected_repr_sequential = 'Sequential(\n' \
            '  (0): Linear(in_features=1, out_features=1, bias=True)\n' \
            ')'
        self.assertEqual(repr(sequential), expected_repr_sequential)

    def test_dir_digit(self):
        model = nn.Sequential(nn.Linear(2, 2))
        keys = dir(model)
        self.assertNotIn('0', keys)

    def test_named_children(self):
        l1 = nn.Linear(2, 2)
        l2 = nn.Linear(2, 2)
        l3 = nn.Linear(2, 2)
        l4 = nn.Linear(2, 2)
        subnet = nn.Sequential(l3, l4)
        s = nn.Sequential()
        with self.assertRaises(KeyError):
            s.add_module('', l1)
        with self.assertRaises(KeyError):
            s.add_module('name.with.dot', l1)
        s.add_module('layer1', l1)
        s.add_module('layer2', l2)
        s.add_module('layer3', l1)
        s.add_module('layer4', l2)
        s.add_module('subnet', subnet)
        self.assertEqual(list(s.named_children()), [('layer1', l1), ('layer2', l2), ('subnet', subnet)])

    def test_modules(self):
        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.l1 = l
                self.l2 = l
                self.param = torch.empty(3, 5)

        l = nn.Linear(10, 20)
        n = Net()
        s = nn.Sequential(n, n, n, n)
        self.assertEqual(list(s.modules()), [s, n, l])

    def test_named_modules(self):
        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.l1 = l
                self.l2 = l
                self.param = torch.empty(3, 5)
                self.block = block
        l = nn.Linear(10, 20)
        l1 = nn.Linear(10, 20)
        l2 = nn.Linear(10, 20)
        block = nn.Sequential()
        block.add_module('linear1', l1)
        block.add_module('linear2', l2)
        n = Net()
        s = nn.Sequential(n, n, n, n)
        self.assertEqual(list(s.named_modules()), [('', s), ('0', n), ('0.l1', l),
                                                   ('0.block', block), ('0.block.linear1', l1),
                                                   ('0.block.linear2', l2)])

    def test_register_buffer_raises_error_if_name_is_not_string(self):
        m = nn.Module()
        expected_error = 'buffer name should be a string. Got '
        with self.assertRaisesRegex(TypeError, expected_error + 'int'):
            m.register_buffer(1, torch.rand(5))
        with self.assertRaisesRegex(TypeError, expected_error + 'NoneType'):
            m.register_buffer(None, torch.rand(5))

    def test_register_buffer_raises_error_if_attr_exists(self):
        m = nn.Module()
        m.attribute_name = 5
        with self.assertRaises(KeyError):
            m.register_buffer('attribute_name', torch.rand(5))

        del m.attribute_name
        m.register_parameter('attribute_name', nn.Parameter())
        with self.assertRaises(KeyError):
            m.register_buffer('attribute_name', torch.rand(5))

        del m.attribute_name
        m.add_module('attribute_name', nn.Module())
        with self.assertRaises(KeyError):
            m.register_buffer('attribute_name', torch.rand(5))

    def test_register_buffer_raises_error_if_not_tensor(self):
        m = nn.Module()
        with self.assertRaises(TypeError):
            m.register_buffer('attribute_name', 5)

    def test_register_buffer_allows_overwriting_with_same_name(self):
        m = nn.Module()
        buffer1 = torch.rand(5)
        buffer2 = buffer1 + 5
        buffer3 = None
        m.register_buffer('buffer_name', buffer1)
        self.assertEqual(m.buffer_name, buffer1)
        m.register_buffer('buffer_name', buffer2)
        self.assertEqual(m.buffer_name, buffer2)
        m.register_buffer('buffer_name', buffer3)
        self.assertEqual(m.buffer_name, buffer3)

    def test_register_parameter_raises_error_if_name_is_not_string(self):
        m = nn.Module()
        expected_error = 'parameter name should be a string. Got '
        with self.assertRaisesRegex(TypeError, expected_error + 'int'):
            m.register_parameter(1, nn.Parameter())
        with self.assertRaisesRegex(TypeError, expected_error + 'NoneType'):
            m.register_parameter(None, nn.Parameter())

    def test_register_parameter_raises_error_if_attr_exists(self):
        m = nn.Module()
        m.attribute_name = 5
        with self.assertRaises(KeyError):
            m.register_parameter('attribute_name', nn.Parameter())

        del m.attribute_name
        m.register_buffer('attribute_name', torch.rand(5))
        with self.assertRaises(KeyError):
            m.register_parameter('attribute_name', nn.Parameter())

        del m.attribute_name
        m.add_module('attribute_name', nn.Module())
        with self.assertRaises(KeyError):
            m.register_parameter('attribute_name', nn.Parameter())

    def test_register_parameter_allows_overwriting_with_same_name(self):
        m = nn.Module()
        param1 = nn.Parameter(torch.rand(5))
        param2 = nn.Parameter(param1.data + 5)
        param3 = None
        m.register_parameter('param_name', param1)
        self.assertEqual(m.param_name, param1)
        m.register_parameter('param_name', param2)
        self.assertEqual(m.param_name, param2)
        m.register_parameter('param_name', param3)
        self.assertEqual(m.param_name, param3)

    def test_add_module_raises_error_if_attr_exists(self):
        m = nn.Module()
        m.attribute_name = 5
        with self.assertRaises(KeyError):
            m.add_module('attribute_name', nn.Module())

        del m.attribute_name
        m.register_buffer('attribute_name', torch.rand(5))
        with self.assertRaises(KeyError):
            m.add_module('attribute_name', nn.Module())

        del m.attribute_name
        m.register_parameter('attribute_name', nn.Parameter())
        with self.assertRaises(KeyError):
            m.add_module('attribute_name', nn.Module())

    def test_Sequential_getitem(self):
        l1 = nn.Linear(10, 20)
        l2 = nn.Linear(20, 30)
        l3 = nn.Linear(30, 40)
        l4 = nn.Linear(40, 50)
        n = nn.Sequential(l1, l2, l3, l4)
        self.assertIs(n[0], l1)
        self.assertIs(n[1], l2)
        self.assertIs(n[2], l3)
        self.assertIs(n[3], l4)
        self.assertIs(n[torch.tensor(3, dtype=torch.int64)], l4)
        self.assertEqual(n[1:], nn.Sequential(l2, l3, l4))
        self.assertEqual(n[3:], nn.Sequential(l4))
        self.assertEqual(n[:-1], nn.Sequential(l1, l2, l3))
        self.assertEqual(n[:-3], nn.Sequential(l1))
        self.assertEqual(n[::-1], nn.Sequential(l4, l3, l2, l1))

    def test_Sequential_setitem(self):
        l1 = nn.Linear(10, 20)
        l2 = nn.Linear(20, 30)
        l3 = nn.Linear(30, 40)
        l4 = nn.Linear(40, 50)
        n = nn.Sequential(l1, l2, l3)
        n[0] = l4
        n[-1] = l4
        n[torch.tensor(1, dtype=torch.int16)] = l1
        self.assertIs(n[0], l4)
        self.assertIs(n[1], l1)
        self.assertIs(n[2], l4)

    def test_Sequential_setitem_named(self):
        l1 = nn.Linear(10, 20)
        l2 = nn.Linear(20, 30)
        l3 = nn.Linear(30, 40)
        l4 = nn.Linear(40, 50)
        n = nn.Sequential(OrderedDict([
            ('linear1', l1),
            ('linear2', l2),
            ('linear3', l3),
        ]))

        n[0] = l4
        n[-1] = l4
        self.assertEqual(n.linear1, l4)
        self.assertEqual(n.linear3, l4)

    def test_Sequential_delitem(self):
        l1 = nn.Linear(10, 20)
        l2 = nn.Linear(20, 30)
        l3 = nn.Linear(30, 40)
        l4 = nn.Linear(40, 50)
        n = nn.Sequential(l1, l2, l3, l4)
        del n[-1]
        self.assertEqual(n, nn.Sequential(l1, l2, l3))
        del n[1::2]
        self.assertEqual(n, nn.Sequential(l1, l3))

    def test_ModuleList(self):
        modules = [nn.ReLU(), nn.Linear(5, 5)]
        module_list = nn.ModuleList(modules)

        def check():
            self.assertEqual(len(module_list), len(modules))
            for m1, m2 in zip(modules, module_list):
                self.assertIs(m1, m2)
            for m1, m2 in zip(modules, module_list.children()):
                self.assertIs(m1, m2)
            for i in range(len(modules)):
                self.assertIs(module_list[i], modules[i])

        check()
        modules += [nn.Conv2d(3, 4, 3)]
        module_list += [modules[-1]]
        check()
        modules.insert(1, nn.Linear(3, 2))
        module_list.insert(1, modules[1])
        check()
        modules.append(nn.Tanh())
        module_list.append(modules[-1])
        check()
        next_modules = [nn.Linear(5, 5), nn.Sigmoid()]
        modules.extend(next_modules)
        module_list.extend(next_modules)
        check()
        modules[2] = nn.Conv2d(5, 3, 2)
        module_list[2] = modules[2]
        check()
        modules[-1] = nn.Conv2d(5, 2, 1)
        module_list[-1] = modules[-1]
        check()
        idx = torch.tensor(2, dtype=torch.int32)
        modules[2] = nn.Conv2d(5, 3, 2)
        module_list[idx] = modules[2]
        self.assertIs(module_list[idx], modules[2])
        check()
        self.assertEqual(module_list[1:], nn.ModuleList(modules[1:]))
        self.assertEqual(module_list[3:], nn.ModuleList(modules[3:]))
        self.assertEqual(module_list[:-1], nn.ModuleList(modules[:-1]))
        self.assertEqual(module_list[:-3], nn.ModuleList(modules[:-3]))
        self.assertEqual(module_list[::-1], nn.ModuleList(modules[::-1]))
        del module_list[-1]
        self.assertEqual(module_list, nn.ModuleList(modules[:-1]))
        del module_list[1::2]
        self.assertEqual(module_list, nn.ModuleList(modules[:-1][0::2]))

        with self.assertRaises(TypeError):
            module_list += nn.ReLU()
        with self.assertRaises(TypeError):
            module_list.extend(nn.ReLU())

        l1 = nn.Linear(1, 2)
        l2 = nn.Linear(2, 3)
        l3 = nn.Linear(3, 2)
        l4 = nn.Linear(2, 3)
        subnet = nn.Sequential(l3, l4)
        s = nn.Sequential(
            OrderedDict([
                ("layer1", l1),
                ("layer2", l2),
                ("layer3", l3),
                ("layer4", l4),
                ("subnet_layer", subnet)
            ])
        )
        modules = list(s.modules())
        module_list = nn.ModuleList()
        module_list.extend(s.modules())
        check()

    def test_ModuleDict(self):
        modules = OrderedDict([
            ('act', nn.ReLU()),
            ('conv', nn.Conv2d(10, 10, 5)),
            ('fc', nn.Linear(5, 5)),
        ])

        module_dict = nn.ModuleDict(modules)

        def check():
            self.assertEqual(len(module_dict), len(modules))
            for k1, m2 in zip(modules, module_dict.children()):
                self.assertIs(modules[k1], m2)
            for k1, k2 in zip(modules, module_dict):
                self.assertIs(modules[k1], module_dict[k2])
            for k in module_dict:
                self.assertIs(module_dict[k], modules[k])
            for k in module_dict.keys():
                self.assertIs(module_dict[k], modules[k])
            for k, v in module_dict.items():
                self.assertIs(modules[k], v)
            for k1, m2 in zip(modules, module_dict.values()):
                self.assertIs(modules[k1], m2)
            for k in modules.keys():
                self.assertTrue(k in module_dict)
        check()

        modules['conv'] = nn.Conv2d(3, 4, 3)
        module_dict['conv'] = modules['conv']
        check()

        next_modules = [
            ('fc2', nn.Linear(5, 5)),
            ('act', nn.Sigmoid()),
        ]
        modules.update(next_modules)
        module_dict.update(next_modules)
        check()

        next_modules = OrderedDict([
            ('fc3', nn.Linear(5, 5)),
            ('act2', nn.Sigmoid()),
        ])
        modules.update(next_modules)
        module_dict.update(next_modules)
        check()

        next_modules = {
            'fc4': nn.Linear(5, 5),
            'act3': nn.Sigmoid()
        }
        modules.update(sorted(next_modules.items()))
        module_dict.update(next_modules)
        check()

        del module_dict['fc']
        del modules['fc']
        check()

        with self.assertRaises(TypeError):
            module_dict.update(nn.ReLU())

        with self.assertRaises(TypeError):
            module_dict.update([nn.ReLU()])

        with self.assertRaises(ValueError):
            module_dict.update([[nn.ReLU()]])

        with self.assertRaises(TypeError):
            module_dict[1] = nn.ReLU()

        s = nn.Sequential(modules)
        module_dict = nn.ModuleDict(s.named_children())
        check()

        c = module_dict.pop('conv')
        self.assertIs(c, modules['conv'])
        modules.pop('conv')
        check()

        module_dict.clear()
        self.assertEqual(len(module_dict), 0)
        modules.clear()
        check()

    def test_ParameterList(self):
        def make_param():
            return Parameter(torch.randn(10, 10))
        parameters = [make_param(), make_param()]
        param_list = nn.ParameterList(parameters)

        def check():
            self.assertEqual(len(parameters), len(param_list))
            for p1, p2 in zip(parameters, param_list):
                self.assertIs(p1, p2)
            for p1, p2 in zip(parameters, param_list.parameters()):
                self.assertIs(p1, p2)
            for i in range(len(parameters)):
                self.assertIs(parameters[i], param_list[i])

        check()
        parameters += [make_param()]
        param_list += [parameters[-1]]
        check()
        parameters.append(make_param())
        param_list.append(parameters[-1])
        check()
        next_params = [make_param(), make_param()]
        parameters.extend(next_params)
        param_list.extend(next_params)
        check()
        parameters[2] = make_param()
        param_list[2] = parameters[2]
        check()
        parameters[-1] = make_param()
        param_list[-1] = parameters[-1]
        check()
        idx = torch.tensor(2, dtype=torch.int32)
        parameters[2] = make_param()
        param_list[idx] = parameters[2]
        self.assertIs(param_list[idx], parameters[2])
        check()
        self.assertEqual(param_list[1:], nn.ParameterList(parameters[1:]))
        self.assertEqual(param_list[3:], nn.ParameterList(parameters[3:]))
        self.assertEqual(param_list[:-1], nn.ParameterList(parameters[:-1]))
        self.assertEqual(param_list[:-3], nn.ParameterList(parameters[:-3]))
        self.assertEqual(param_list[::-1], nn.ParameterList(parameters[::-1]))

        with self.assertRaises(TypeError):
            param_list += make_param()
        with self.assertRaises(TypeError):
            param_list.extend(make_param())

        l1 = nn.Linear(1, 2)
        l2 = nn.Linear(2, 3)
        l3 = nn.Linear(3, 2)
        l4 = nn.Linear(2, 3)
        subnet = nn.Sequential(l3, l4)
        s = nn.Sequential(
            OrderedDict([
                ("layer1", l1),
                ("layer2", l2),
                ("layer3", l3),
                ("layer4", l4),
                ("subnet_layer", subnet)
            ])
        )
        parameters = list(s.parameters())
        param_list = nn.ParameterList()
        param_list.extend(s.parameters())
        check()

    def test_ParameterDict(self):
        parameters = OrderedDict([
            ('p1', Parameter(torch.randn(10, 10))),
            ('p2', Parameter(torch.randn(10, 10))),
            ('p3', Parameter(torch.randn(10, 10))),
        ])

        parameter_dict = nn.ParameterDict(parameters)

        def check():
            self.assertEqual(len(parameter_dict), len(parameters))
            for k1, m2 in zip(parameters, parameter_dict.parameters()):
                self.assertIs(parameters[k1], m2)
            for k1, k2 in zip(parameters, parameter_dict):
                self.assertIs(parameters[k1], parameter_dict[k2])
            for k in parameter_dict:
                self.assertIs(parameter_dict[k], parameters[k])
            for k in parameter_dict.keys():
                self.assertIs(parameter_dict[k], parameters[k])
            for k, v in parameter_dict.items():
                self.assertIs(v, parameters[k])
            for k1, m2 in zip(parameters, parameter_dict.values()):
                self.assertIs(parameters[k1], m2)
            for k in parameters.keys():
                self.assertTrue(k in parameter_dict)

        check()

        parameters['p4'] = Parameter(torch.randn(10, 10))
        parameter_dict['p4'] = parameters['p4']
        check()

        next_parameters = [
            ('p5', Parameter(torch.randn(10, 10))),
            ('p2', Parameter(torch.randn(10, 10))),
        ]
        parameters.update(next_parameters)
        parameter_dict.update(next_parameters)
        check()

        next_parameters = OrderedDict([
            ('p6', Parameter(torch.randn(10, 10))),
            ('p5', Parameter(torch.randn(10, 10))),
        ])
        parameters.update(next_parameters)
        parameter_dict.update(next_parameters)
        check()

        next_parameters = {
            'p8': Parameter(torch.randn(10, 10)),
            'p7': Parameter(torch.randn(10, 10))
        }
        parameters.update(sorted(next_parameters.items()))
        parameter_dict.update(next_parameters)
        check()

        del parameter_dict['p3']
        del parameters['p3']
        check()

        with self.assertRaises(TypeError):
            parameter_dict.update(1)

        with self.assertRaises(TypeError):
            parameter_dict.update([1])

        with self.assertRaises(ValueError):
            parameter_dict.update(Parameter(torch.randn(10, 10)))

        with self.assertRaises(TypeError):
            parameter_dict[1] = Parameter(torch.randn(10, 10))

        p_pop = parameter_dict.pop('p4')
        self.assertIs(p_pop, parameters['p4'])
        parameters.pop('p4')
        check()

        parameter_dict.clear()
        self.assertEqual(len(parameter_dict), 0)
        parameters.clear()
        check()

    def test_add_module(self):
        l = nn.Linear(10, 20)
        net = nn.Module()
        net.l = l
        net.l2 = l
        net.add_module('empty', None)
        self.assertEqual(net.l, l)
        self.assertEqual(net.l2, l)
        self.assertEqual(net.empty, None)
        net.add_module('l3', l)
        self.assertEqual(net.l3, l)
        l3 = nn.Linear(20, 10)
        net.add_module('l', l3)
        self.assertEqual(net.l, l3)
        self.assertRaises(TypeError, lambda: net.add_module('x', 'non-module'))
        self.assertRaisesRegex(TypeError, 'module name should be a string. Got int',
                               lambda: net.add_module(1, l))
        self.assertRaisesRegex(TypeError, 'module name should be a string. Got NoneType',
                               lambda: net.add_module(None, l))

    def test_module_to_argparse(self):
        net = nn.Sequential(nn.Linear(3, 3))
        cpu = torch.device('cpu')
        with self.assertRaises(TypeError):
            net.to(cpu, True)
        with self.assertRaises(TypeError):
            net.to(torch.long)
        with self.assertRaises(TypeError):
            net.to(None, True)
        with self.assertRaises(TypeError):
            net.to(cpu, torch.long, True)
        with self.assertRaises(TypeError):
            net.to(cpu, dtype=torch.long, non_blocking=True)
        with self.assertRaises(TypeError):
            net.to([])
        with self.assertRaises(TypeError):
            net.to({}, non_blocking=True)
        with self.assertRaises(TypeError):
            net.to(torch.tensor(3, dtype=torch.long), non_blocking=True)
        with self.assertRaises(TypeError):
            net.to(cpu, torch.tensor(3, dtype=torch.long), non_blocking=True)

    def test_type(self):
        l = nn.Linear(10, 20)
        net = nn.Module()
        net.l = l
        net.l2 = l
        net.add_module('empty', None)
        net.register_buffer('indices', torch.LongTensor(1))
        net.float()
        self.assertIsInstance(l.weight.data, torch.FloatTensor)
        self.assertIsInstance(l.bias.data, torch.FloatTensor)
        self.assertIsInstance(net.indices, torch.LongTensor)
        net.double()
        self.assertIsInstance(l.weight.data, torch.DoubleTensor)
        self.assertIsInstance(l.bias.data, torch.DoubleTensor)
        self.assertIsInstance(net.indices, torch.LongTensor)
        net.to(torch.half)
        self.assertIsInstance(l.weight.data, torch.HalfTensor)
        self.assertIsInstance(l.bias.data, torch.HalfTensor)
        self.assertIsInstance(net.indices, torch.LongTensor)
        if TEST_CUDA:
            net.float().cuda()
            self.assertIsInstance(l.weight.data, torch.cuda.FloatTensor)
            self.assertIsInstance(l.bias.data, torch.cuda.FloatTensor)
            self.assertIsInstance(net.indices, torch.cuda.LongTensor)
            net.cpu()
            self.assertIsInstance(l.weight.data, torch.FloatTensor)
            self.assertIsInstance(l.bias.data, torch.FloatTensor)
            self.assertIsInstance(net.indices, torch.LongTensor)
            net.to("cuda", torch.double, True)
            self.assertIsInstance(l.weight.data, torch.cuda.DoubleTensor)
            self.assertIsInstance(l.bias.data, torch.cuda.DoubleTensor)
            self.assertIsInstance(net.indices, torch.cuda.LongTensor)
            net.to(torch.empty(1, device="cuda:0", dtype=torch.half))
            self.assertIsInstance(l.weight.data, torch.cuda.HalfTensor)
            self.assertIsInstance(l.bias.data, torch.cuda.HalfTensor)
            self.assertIsInstance(net.indices, torch.cuda.LongTensor)
        net.to(torch.device("cpu"), non_blocking=True)
        self.assertIsInstance(l.weight.data, torch.HalfTensor)
        self.assertIsInstance(l.bias.data, torch.HalfTensor)
        self.assertIsInstance(net.indices, torch.LongTensor)
        net.type(torch.FloatTensor)
        self.assertIsInstance(l.weight.data, torch.FloatTensor)
        self.assertIsInstance(l.bias.data, torch.FloatTensor)
        net.to(torch.DoubleTensor(1))
        self.assertIsInstance(l.weight.data, torch.DoubleTensor)
        self.assertIsInstance(l.bias.data, torch.DoubleTensor)
        if TEST_CUDA:
            net.type(torch.cuda.FloatTensor)
            self.assertIsInstance(l.weight.data, torch.cuda.FloatTensor)
            self.assertIsInstance(l.bias.data, torch.cuda.FloatTensor)

    def test_non_leaf_parameters(self):
        l1 = nn.Linear(10, 10)
        l2 = nn.Linear(10, 10)

        def assign_weight():
            l2.weight = l1.weight + 2

        self.assertRaises(TypeError, assign_weight)
        # This should work though
        l2.weight = Parameter(torch.randn(10, 10))

    def test_clip_grad_norm(self):
        l = nn.Linear(10, 10)
        max_norm = 2

        def compute_norm(norm_type):
            norm_type = float(norm_type)
            if norm_type != inf:
                total_norm = 0
                for p in l.parameters():
                    total_norm += p.grad.data.abs().pow(norm_type).sum()
                return pow(total_norm, 1. / norm_type)
            else:
                return max(p.grad.data.abs().max() for p in l.parameters())

        def compare_scaling(grads):
            p_scale = [p.grad.data.div(g).view(-1) for p, g in zip(l.parameters(), grads)]
            scale = torch.cat(p_scale)
            self.assertEqual(scale.std(), 0)
            return scale[0]

        grads = torch.arange(1., 101).view(10, 10), torch.ones(10).div(1000)
        for norm_type in [0.5, 1.5, 2, 4, 'inf']:
            for p, g in zip(l.parameters(), grads):
                p._grad = Variable(g.clone().view_as(p.data))
            norm_before = compute_norm(norm_type)
            norm = clip_grad_norm_(l.parameters(), max_norm, norm_type=norm_type)
            norm_after = compute_norm(norm_type)
            self.assertEqual(norm, norm_before)
            self.assertEqual(norm_after, max_norm)
            self.assertLessEqual(norm_after, norm_before)
            compare_scaling(grads)

        # Small gradients should be left unchanged
        grads = torch.rand(10, 10).div(10000), torch.ones(10).div(500)
        for norm_type in [0.5, 1.5, 2, 4, 'inf']:
            for p, g in zip(l.parameters(), grads):
                p.grad.data.copy_(g)
            norm_before = compute_norm(norm_type)
            norm = clip_grad_norm_(l.parameters(), max_norm, norm_type=norm_type)
            norm_after = compute_norm(norm_type)
            self.assertEqual(norm, norm_before)
            self.assertEqual(norm_before, norm_after)
            self.assertLessEqual(norm_after, max_norm)
            scale = compare_scaling(grads)
            self.assertEqual(scale, 1)

        # Should accept a single Tensor as input
        p1, p2 = torch.randn(10, 10), torch.randn(10, 10)
        g = torch.arange(1., 101).view(10, 10)
        p1._grad = g.clone()
        p2._grad = g.clone()
        for norm_type in [0.5, 1.5, 2, 4, 'inf']:
            clip_grad_norm_(p1, max_norm, norm_type=norm_type)
            clip_grad_norm_([p2], max_norm, norm_type=norm_type)
            self.assertEqual(p1.grad, p2.grad)

    def test_clip_grad_value(self):
        l = nn.Linear(10, 10)
        clip_value = 2.5

        grad_w, grad_b = torch.arange(-50., 50).view(10, 10).div_(5), torch.ones(10).mul_(2)
        for grad_list in [[grad_w, grad_b], [grad_w, None]]:
            for p, g in zip(l.parameters(), grad_list):
                p._grad = g.clone().view_as(p.data) if g is not None else g

        clip_grad_value_(l.parameters(), clip_value)
        for p in filter(lambda p: p.grad is not None, l.parameters()):
            self.assertLessEqual(p.grad.data.max(), clip_value)
            self.assertGreaterEqual(p.grad.data.min(), -clip_value)

        # Should accept a single Tensor as input
        p1, p2 = torch.randn(10, 10), torch.randn(10, 10)
        g = torch.arange(-50., 50).view(10, 10).div_(5)
        p1._grad = g.clone()
        p2._grad = g.clone()
        clip_grad_value_(p1, clip_value)
        clip_grad_value_([p2], clip_value)
        self.assertEqual(p1.grad, p2.grad)

    def test_parameters_to_vector(self):
        conv1 = nn.Conv2d(3, 10, 5)
        fc1 = nn.Linear(10, 20)
        model = nn.Sequential(conv1, fc1)

        vec = parameters_to_vector(model.parameters())
        self.assertEqual(vec.size(0), 980)

    def test_vector_to_parameters(self):
        conv1 = nn.Conv2d(3, 10, 5)
        fc1 = nn.Linear(10, 20)
        model = nn.Sequential(conv1, fc1)

        vec = Variable(torch.arange(0., 980))
        vector_to_parameters(vec, model.parameters())

        sample = next(model.parameters())[0, 0, 0]
        self.assertTrue(torch.equal(sample.data, vec.data[:5]))

    # We don't want to make propagating NaN a hard requirement on ops, but for
    # these easy ones, we should make them do so.
    def _test_nonlinearity_propagate_nan(self, device):
        def test(nonlinearity, *args, **kwargs):
            x = torch.tensor([nan], device=device)
            fn = getattr(F, nonlinearity)
            try:
                self.assertTrue(math.isnan(fn(x, *args, **kwargs).item()))
            except Exception as e:
                if 'not implemented' not in str(e):
                    raise

        test('relu')
        test('relu', inplace=True)
        test('relu6')
        test('elu')
        test('selu')
        test('celu')
        test('rrelu')
        test('rrelu', inplace=True)
        test('hardtanh')
        test('tanh')
        test('sigmoid')
        test('logsigmoid')
        test('hardshrink')
        test('tanhshrink')
        test('softsign')
        test('softmin', 0)
        test('softmax', 0)
        test('log_softmax', 0)
        test('leaky_relu', 0.2)
        test('threshold', 3, 2)
        test('threshold', 3, 2, inplace=True)

    def test_nonlinearity_propagate_nan(self):
        self._test_nonlinearity_propagate_nan('cpu')

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_nonlinearity_propagate_nan_cuda(self):
        self._test_nonlinearity_propagate_nan('cuda')

    def test_weight_norm(self):
        input = torch.randn(3, 5)
        m = nn.Linear(5, 7)
        expected_output = m(input)

        # add weight normalization
        m = torch.nn.utils.weight_norm(m)
        self.assertEqual(m.weight_v.size(), m.weight.size())
        self.assertEqual(m.weight_g.size(), (7, 1))
        self.assertEqual(m(input), expected_output)

        # remove weight norm
        m = torch.nn.utils.remove_weight_norm(m)
        self.assertFalse(hasattr(m, 'weight_g'))
        self.assertFalse(hasattr(m, 'weight_v'))
        self.assertEqual(m(input), expected_output)

        # test with dim=1
        m = torch.nn.utils.weight_norm(m, dim=1)
        self.assertEqual(m.weight_v.size(), m.weight.size())
        self.assertEqual(m.weight_g.size(), (1, 5))
        self.assertEqual(m(input), expected_output)

        # test with dim=None
        m = nn.Linear(5, 7)
        expected_output = m(input)
        m = torch.nn.utils.weight_norm(m, dim=None)
        self.assertEqual(m(input), expected_output)

        with self.assertRaisesRegex(RuntimeError, 'register two weight_norm hooks'):
            m = torch.nn.utils.weight_norm(m)
            m = torch.nn.utils.weight_norm(m)

    def test_weight_norm_pickle(self):
        m = torch.nn.utils.weight_norm(nn.Linear(5, 7))
        m = pickle.loads(pickle.dumps(m))
        self.assertIsInstance(m, nn.Linear)

    def test_spectral_norm(self):
        input = torch.randn(3, 5)
        m = nn.Linear(5, 7)
        m = torch.nn.utils.spectral_norm(m)

        self.assertEqual(m.weight_u.size(), torch.Size([m.weight.size(0)]))
        # weight_orig should be trainable
        self.assertTrue(hasattr(m, 'weight_orig'))
        self.assertTrue('weight_orig' in m._parameters)
        # weight_u should be just a reused buffer
        self.assertTrue(hasattr(m, 'weight_u'))
        self.assertTrue('weight_u' in m._buffers)
        self.assertTrue('weight_v' in m._buffers)
        # weight should be a plain attribute, not counted as a buffer or a param
        self.assertFalse('weight' in m._buffers)
        self.assertFalse('weight' in m._parameters)
        # it should also be sharing storage as `weight_orig`
        self.assertEqual(m.weight_orig.storage(), m.weight.storage())
        self.assertEqual(m.weight_orig.size(), m.weight.size())
        self.assertEqual(m.weight_orig.stride(), m.weight.stride())

        m = torch.nn.utils.remove_spectral_norm(m)
        self.assertFalse(hasattr(m, 'weight_orig'))
        self.assertFalse(hasattr(m, 'weight_u'))
        # weight should be converted back as a parameter
        self.assertTrue(hasattr(m, 'weight'))
        self.assertTrue('weight' in m._parameters)

        with self.assertRaisesRegex(RuntimeError, 'register two spectral_norm hooks'):
            m = torch.nn.utils.spectral_norm(m)
            m = torch.nn.utils.spectral_norm(m)

        # test correctness in training/eval modes and cpu/multi-gpu settings
        for apply_dp in (True, False):
            if apply_dp:
                if not TEST_MULTIGPU:
                    continue
                device = torch.device('cuda:0')

                def maybe_wrap(m):
                    return torch.nn.DataParallel(m, [0, 1])
            else:
                device = torch.device('cpu')

                def maybe_wrap(m):
                    return m

            for requires_grad in (True, False):
                m = nn.Linear(3, 4).to(device)
                m.weight.requires_grad_(requires_grad)
                m = torch.nn.utils.spectral_norm(m)
                wrapped_m = maybe_wrap(m)
                self.assertTrue(hasattr(m, 'weight_u'))
                u0 = m.weight_u.clone()
                v0 = m.weight_v.clone()

                # TEST TRAINING BEHAVIOR

                # assert that u and v are updated
                input = torch.randn(2, 3, device=device)
                out = wrapped_m(input)
                self.assertNotEqual(u0, m.weight_u)
                self.assertNotEqual(v0, m.weight_v)

                # assert that backprop reaches weight_orig
                # can't use gradcheck because the function changes as we
                # activate through it in training mode
                if requires_grad:
                    torch.autograd.grad(out.sum(), m.weight_orig)

                # test backward works with multiple forwards
                # it uses training mode so we need to reset `u` and `v` vectors
                # to same value at beginning for finite difference test to pass
                saved_u = m.weight_u.clone()
                saved_v = m.weight_v.clone()

                def fn(input):
                    m.weight_u.data.copy_(saved_u)
                    m.weight_v.data.copy_(saved_v)
                    out0 = wrapped_m(input)
                    out1 = wrapped_m(input)
                    return out0 + out1

                torch.autograd.gradcheck(fn, (input.clone().requires_grad_(),))

                # test removing
                pre_remove_out = wrapped_m(input)
                m = torch.nn.utils.remove_spectral_norm(m)
                self.assertEqual(wrapped_m(input), pre_remove_out)

                m = torch.nn.utils.spectral_norm(m)
                for _ in range(3):
                    pre_remove_out = wrapped_m(input)
                m = torch.nn.utils.remove_spectral_norm(m)
                self.assertEqual(wrapped_m(input), pre_remove_out)

                # TEST EVAL BEHAVIOR

                m = torch.nn.utils.spectral_norm(m)
                wrapped_m(input)
                last_train_out = wrapped_m(input)
                last_train_u = m.weight_u.clone()
                last_train_v = m.weight_v.clone()
                wrapped_m.zero_grad()
                wrapped_m.eval()

                eval_out0 = wrapped_m(input)
                # assert eval gives same result as last training iteration
                self.assertEqual(eval_out0, last_train_out)
                # assert doing more iteartion in eval don't change things
                self.assertEqual(eval_out0, wrapped_m(input))
                self.assertEqual(last_train_u, m.weight_u)
                self.assertEqual(last_train_v, m.weight_v)

                # FIXME: the code below is flaky when executed with DataParallel
                # see https://github.com/pytorch/pytorch/issues/13818
                if apply_dp:
                    continue

                # test backward works with multiple forwards in mixed training
                # and eval modes
                # it uses training mode so we need to reset `u` and `v` vectors
                # to same value at beginning for finite difference test to pass
                saved_u = m.weight_u.clone()
                saved_v = m.weight_v.clone()

                def fn(input):
                    m.weight_u.data.copy_(saved_u)
                    m.weight_v.data.copy_(saved_v)
                    wrapped_m.train()
                    out0 = wrapped_m(input)
                    wrapped_m.eval()
                    out1 = wrapped_m(input)
                    wrapped_m.train()
                    out2 = wrapped_m(input)
                    wrapped_m.eval()
                    out3 = wrapped_m(input)
                    return out0 + out1 + out2 + out3

                torch.autograd.gradcheck(fn, (input.clone().requires_grad_(),))

                # assert that backprop reaches weight_orig in eval
                if requires_grad:
                    def fn(weight):
                        return wrapped_m(input)

                    torch.autograd.gradcheck(fn, (m.weight_orig,))

    def test_spectral_norm_load_state_dict(self):
        inp = torch.randn(2, 3)
        for activate_times in (0, 3):
            # Test backward compatibility
            # At version None -> 1: weight becomes not a buffer and v vector becomes a buffer
            m = nn.Linear(3, 5)
            snm = torch.nn.utils.spectral_norm(m)
            snm.train()
            for _ in range(activate_times):
                snm(inp)

            # craft a version None state_dict
            version_none_state_dict = deepcopy(snm.state_dict())
            self.assertEqual({'weight_orig', 'bias', 'weight_u', 'weight_v'}, set(version_none_state_dict.keys()))
            self.assertIn('spectral_norm', version_none_state_dict._metadata[''])
            del version_none_state_dict._metadata['']['spectral_norm']       # remove metadata info
            del version_none_state_dict['weight_v']                          # remove v vector
            version_none_state_dict['weight'] = snm.weight.detach().clone()  # set W as a buffer

            # normal state_dict
            version_latest_state_dict = deepcopy(snm.state_dict())

            snm.eval()
            out0_eval = snm(inp)
            snm.train()
            out1_train = snm(inp)
            out2_train = snm(inp)
            snm.eval()
            out3_eval = snm(inp)

            snm.load_state_dict(version_none_state_dict)
            if activate_times > 0:
                # since in loading version None state dict, we assume that the
                # values in the state dict have gone through at lease one
                # forward, we only test for equivalence when activate_times > 0.
                snm.eval()
                self.assertEqual(out0_eval, snm(inp))
                snm.train()
                self.assertEqual(out1_train, snm(inp))
                self.assertEqual(out2_train, snm(inp))
                snm.eval()
                self.assertEqual(out3_eval, snm(inp))

            # Test normal loading
            snm.load_state_dict(version_latest_state_dict)
            snm.eval()
            self.assertEqual(out0_eval, snm(inp))
            snm.train()
            self.assertEqual(out1_train, snm(inp))
            self.assertEqual(out2_train, snm(inp))
            snm.eval()
            self.assertEqual(out3_eval, snm(inp))

    def test_spectral_norm_dim(self):
        inp = torch.randn(2, 3, 10, 12)
        m = nn.ConvTranspose2d(3, 4, (5, 6))
        m = torch.nn.utils.spectral_norm(m)
        # this should not run into incompatible shapes
        x = m(inp)
        # check that u refers to the same dimension
        self.assertEqual(m.weight_u.shape, m.weight_orig[0, :, 0, 0].shape)

    def test_spectral_norm_forward(self):
        input = torch.randn(3, 5)
        m = nn.Linear(5, 7)
        m = torch.nn.utils.spectral_norm(m)
        # naive forward
        _weight, _bias, _u = m.weight_orig, m.bias, m.weight_u
        _weight_mat = _weight.view(_weight.size(0), -1)
        _v = torch.mv(_weight_mat.t(), _u)
        _v = F.normalize(_v, dim=0, eps=1e-12)
        _u = torch.mv(_weight_mat, _v)
        _u = F.normalize(_u, dim=0, eps=1e-12)
        _weight.data /= torch.dot(_u, torch.matmul(_weight_mat, _v))
        out_hat = torch.nn.functional.linear(input, _weight, _bias)
        expect_out = m(input)
        self.assertAlmostEqual(expect_out, out_hat)

    def test_spectral_norm_pickle(self):
        m = torch.nn.utils.spectral_norm(nn.Linear(5, 7))
        m = pickle.loads(pickle.dumps(m))
        self.assertIsInstance(m, nn.Linear)

    def test_threshold_int(self):
        x = torch.tensor([-3, -2, -1, 0, 1, 2, 3])
        expected = torch.tensor([99, 99, 99, 99, 1, 2, 3])
        self.assertEqual(F.threshold(x, 0, 99), expected)

    def test_embedding_sparse_basic(self):
        embedding = nn.Embedding(10, 20, sparse=True)
        input = Variable(torch.LongTensor([[0, 2, 4, 5], [4, 3, 0, 9]]))
        embedding(input).sum().backward()
        self.assertTrue(embedding.weight.grad.is_sparse)
        self.assertEqual(embedding.weight.grad.shape, embedding.weight.shape)

    def test_embedding_sparse_empty_tensor(self):
        embedding = nn.Embedding(0, 0, sparse=True)
        input = torch.tensor([], dtype=torch.int64)
        embedding(input).sum().backward()
        self.assertTrue(embedding.weight.grad.is_sparse)
        self.assertEqual(embedding.weight.grad.shape, embedding.weight.shape)

        embedding = nn.Embedding(10, 0, sparse=True)
        input = torch.LongTensor([[0, 2, 4, 5], [4, 3, 0, 9]])
        embedding(input).sum().backward()
        self.assertTrue(embedding.weight.grad.is_sparse)
        self.assertEqual(embedding.weight.grad.shape, embedding.weight.shape)

    def _test_embedding_dense_grad(self, dev):
        embd = nn.Embedding(20, 20).to(dev)
        weight = embd.weight

        def fn_wrapper(dev):
            def fn(weight):
                inp = torch.tensor([[0, 1, 1, 2], [3, 5, 7, 11]], dtype=torch.long).to(dev)
                return torch.nn.functional.embedding(inp, weight)
            return fn

        fn = fn_wrapper(dev)
        _assertGradAndGradgradChecks(self, fn, (weight, ))

    def test_embedding_dense_grad(self):
        self._test_embedding_dense_grad("cpu")

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_embedding_dense_grad_cuda(self):
        self._test_embedding_dense_grad("cuda")

    def test_move_sparse_half_embedding(self):
        embedding = nn.Embedding(10, 3, sparse=True)
        self.assertEqual(embedding.weight.device.type, 'cpu')
        self.assertEqual(embedding.weight.dtype, torch.float64)
        embedding.to(torch.float16)
        self.assertEqual(embedding.weight.dtype, torch.float16)
        self.assertEqual(embedding.embedding_dim, 3)
        self.assertEqual(embedding.num_embeddings, 10)

        if torch.cuda.is_available():
            embedding.to('cuda')
            self.assertEqual(embedding.weight.device.type, 'cuda')
            embedding.to('cpu')
            self.assertEqual(embedding.weight.device.type, 'cpu')

    def test_embedding_sparse_backward(self):
        self._test_embedding_backward()

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_embedding_sparse_half_backward(self):
        # same as test_embedding_sparse_backward above but testing half types in
        # cuda. cpu sum not supported for half types.
        self._test_embedding_backward('cuda', torch.float16)

    def _test_embedding_backward(self, device='cpu', dtype=torch.float64):
        embedding = nn.Embedding(10, 3, sparse=True)
        tensor = torch.tensor([[7, 1, 3]])
        ones = torch.tensor(1.).expand(3, 3)
        tensorTwice = tensor.repeat(1, 2)
        onesTwice = torch.cat((ones, ones))

        embedding = embedding.to(dtype=dtype).to(device)
        tensor = tensor.to(device)
        ones = ones.to(device)
        tensorTwice = tensorTwice.to(device)
        onesTwice = onesTwice.to(device)

        embedding.zero_grad()
        embedding(tensor[0]).sum().backward()
        self.assertEqual(embedding.weight.grad._indices(), tensor)
        self.assertEqual(embedding.weight.grad._values(), ones)

        embedding.zero_grad()
        embedding(tensor[0]).sum().backward()
        embedding(tensor[0]).sum().backward()
        self.assertEqual(embedding.weight.grad._indices(), tensorTwice)
        self.assertEqual(embedding.weight.grad._values(), onesTwice)

        embedding.zero_grad()
        embedding(tensor[0]).sum().backward()
        tensor[0, 0] = 8
        embedding(tensor[0]).sum().backward()
        tensorTwice[0, 3] = 8
        self.assertEqual(embedding.weight.grad._indices(), tensorTwice)
        self.assertEqual(embedding.weight.grad._values(), onesTwice)

    def test_embedding_padding_idx(self):
        embedding = nn.Embedding(10, 20, padding_idx=0)
        input = Variable(torch.LongTensor([[0, 2, 4, 5], [4, 3, 0, 9]]))
        output = embedding(input)
        self.assertEqual(output[0][0].sum(), 0)
        self.assertEqual(output[1][2].sum(), 0)

        embedding = nn.Embedding(10, 20, padding_idx=0, sparse=True)
        input = Variable(torch.LongTensor([[0, 2, 4, 5], [4, 3, 0, 9]]))
        output = embedding(input)
        self.assertEqual(output[0][0].sum(), 0)
        self.assertEqual(output[1][2].sum(), 0)

        # negative indexing check for padding_idx
        # padding_idx=-2, num_embeddings=10 ==> index 8 padded
        embedding = nn.Embedding(10, 20, padding_idx=-2)
        input = Variable(torch.LongTensor([[0, 2, 8, 5], [4, 8, 0, 9]]))
        output = embedding(input)
        self.assertEqual(output[0][2].sum(), 0)
        self.assertEqual(output[1][1].sum(), 0)

        embedding = nn.Embedding(10, 20, padding_idx=-2, sparse=True)
        input = Variable(torch.LongTensor([[0, 2, 8, 5], [4, 8, 0, 9]]))
        output = embedding(input)
        self.assertEqual(output[0][2].sum(), 0)
        self.assertEqual(output[1][1].sum(), 0)

        # out of bounds check for padding_idx
        self.assertRaises(AssertionError, nn.Embedding, num_embeddings=10, embedding_dim=20, padding_idx=25)
        self.assertRaises(AssertionError, nn.Embedding, num_embeddings=10, embedding_dim=20, padding_idx=-25)

        # test backward when input contains padding_idx
        padding_idx = 0
        embedding = nn.Embedding(5, 2, padding_idx=padding_idx)
        for n in (1, 2):
            for other_indices in ([], [1, 3], [2]):
                indices = torch.LongTensor(other_indices + [padding_idx] * n)
                pre = embedding.weight[padding_idx].clone()
                embedding(indices).sum().backward()
                after = (embedding.weight + embedding.weight.grad)[padding_idx]
                embedding.zero_grad()
                self.assertEqual(after, pre)

                # test double backward
                emb_sum = embedding(indices).sum()
                emb_grad = torch.autograd.grad(outputs=emb_sum, inputs=list(embedding.parameters()), retain_graph=True)
                scalar = emb_grad[0].sum() + emb_sum
                scalar.backward()
                after = (embedding.weight + embedding.weight.grad)[padding_idx]
                embedding.zero_grad()
                self.assertEqual(after, pre)

    def test_embedding_max_norm(self):
        embedding = nn.Embedding(22, 5, max_norm=1.0)
        input = Variable(torch.LongTensor([2, 8, 8, 6]))
        output = embedding(input)
        self.assertEqual(output[1], output[2])
        self.assertTrue(output.data.norm(p=2, dim=1).le(1).all())

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_embedding_max_norm_cuda(self, dtype=torch.float):
        embedding = nn.Embedding(22, 5, max_norm=1.0).to("cuda", dtype=dtype)
        # nn.Embedding only takes LongTensor as input
        input = torch.tensor([2, 8, 8, 6], device="cuda", dtype=torch.long)
        output = embedding(input)
        self.assertEqual(output[1], output[2])
        self.assertTrue(output.data.norm(p=2, dim=1).le(1).all())

    def test_embedding_from_pretrained(self):
        a = torch.Tensor([[1, 2, 3], [4, 5, 6]])
        embedding = nn.Embedding.from_pretrained(a)
        self.assertEqual(a, embedding.weight.data)

        input = torch.LongTensor([0, 1])
        output = embedding(input)
        self.assertEqual(a, output)

    def test_embedding_from_pretrained_options(self):
        a = torch.Tensor([[1, 2, 3], [4, 5, 6]])
        opts = {
            "max_norm": 2.,
            "norm_type": .5,
            "scale_grad_by_freq": False,
            "sparse": True
        }
        embedding = nn.Embedding.from_pretrained(a, **opts)
        input = torch.LongTensor([0, 1])
        output = embedding(input)
        # test output and that weight matrix was renormalized
        self.assertEqual(a, output)
        self.assertTrue(a.ne(torch.arange(1, 7, dtype=a.dtype).view(2, 3)).all())
        self.assertTrue(output.data.norm(p=opts["norm_type"], dim=1).le(opts["max_norm"]).all())

    def test_embedding_functional(self):
        a = torch.tensor([
            [1, 3, 2],
            [0, 2, 1]
        ], dtype=torch.long)
        embeddings = torch.rand(4, 3, requires_grad=True)

        embed_old = torch.nn.Embedding(4, 3)
        embed_old.weight.data = embeddings.data
        res_old = embed_old(a)

        res_F = F.embedding(a, embeddings)
        self.assertEqual(res_old, res_F)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types([torch.float, torch.half])
    @skipIfRocm
    def test_softmax_dtype(self, dtype=torch.float):
        input = torch.rand(32, 100, device="cuda", dtype=dtype, requires_grad=True)
        inputf = input.to(torch.float).detach().requires_grad_(True)
        out = F.softmax(input, dim=-1, dtype=torch.float)
        outf = F.softmax(inputf, dim=-1)
        # should be bitwise equal
        self.assertEqual(out, outf, prec=0)
        gO = torch.empty_like(outf).uniform_()
        out.backward(gO)
        outf.backward(gO)
        # should be bitwise equal
        self.assertEqual(input.grad, inputf.grad.to(dtype), prec=0)

    def _test_softmax_backward(self, device):
        if device.type == 'cuda':
            dtypes = [torch.float, torch.half]
        else:
            dtypes = [torch.float]
        # FIXME: add (10, 0) after https://github.com/pytorch/pytorch/issues/17262 is fixed
        sizes = [(0, 10), (32, 20)]
        for fn in [F.softmax, F.log_softmax]:
            for dtype in dtypes:
                for size in sizes:
                    input = torch.rand(size, device=device, dtype=dtype, requires_grad=True)
                    output = fn(input, dtype=torch.float, dim=1).sum()
                    grad_input, = torch.autograd.grad(output, input, create_graph=True)
                    grad_input.sum().backward()

    def test_softmax_backward(self):
        self._test_softmax_backward(torch.device('cpu'))

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_softmax_backward_cuda(self):
        self._test_softmax_backward(torch.device('cuda'))

    def _test_gumbel_softmax_st_shapes(self, cuda, dtype, shape, dim, count_expected):
        logits = torch.randn(shape, dtype=torch.float)
        logits = logits.to(dtype)
        if cuda:
            logits = logits.cuda()

        y_draw = F.gumbel_softmax(logits, hard=True, dim=dim)

        # All values positive
        self.assertGreaterEqual(y_draw.min(), 0)
        # Shape unchanged
        self.assertTrue(y_draw.shape == logits.shape)
        # One choice per draw
        self.assertEqual(y_draw.sum(), count_expected, prec=torch.finfo(y_draw.dtype).eps)

    def _test_gumbel_softmax_straight_through(self, cuda, dtype):
        num_draws = 100

        logits = torch.tensor([[0.2, 0.8, 0.1]])
        logits = logits.reshape([1, 3])
        logits = logits.to(dtype).requires_grad_()
        if cuda:
            logits = logits.cuda()
        probs = logits.softmax(dim=-1)

        counts = torch.zeros_like(logits)
        for _ in range(num_draws):
            y_draw = F.gumbel_softmax(logits, hard=True)
            counts = counts + y_draw

        # All values positive
        self.assertGreaterEqual(y_draw.min(), 0)
        # Each experiment should result in 1 draw.
        self.assertEqual(counts.sum(), num_draws, prec=torch.finfo(counts.dtype).eps)

        # check results is asymptotically as expected.
        expected = probs * num_draws
        # ~z is approximately N(0,1) for unbiased count
        z = (counts - expected) / (expected * (1 - probs)).sqrt()
        # A (lazy) approximate 99% two-sided test:
        # occurs with prob alpha~>=0.01 if unbiased
        self.assertLess(z.abs().max().item(), 2.58)

    def _test_gumbel_softmax_grad(self, cuda, dtype):
        # "hard" and "not hard" should propagate same gradient.
        device = torch.device("cuda") if cuda else torch.device("cpu")
        logits_soft = torch.zeros(10, 10, dtype=dtype, device=device, requires_grad=True)
        logits_hard = torch.zeros(10, 10, dtype=dtype, device=device, requires_grad=True)

        seed = torch.random.get_rng_state()
        y_soft = F.gumbel_softmax(logits_soft, hard=False)
        torch.random.set_rng_state(seed)
        y_hard = F.gumbel_softmax(logits_hard, hard=True)

        y_soft.sum().backward()
        y_hard.sum().backward()

        # 2eps = 1x addition + 1x subtraction.
        tol = 2 * torch.finfo(dtype).eps
        self.assertAlmostEqual(logits_soft.grad, logits_hard.grad, delta=tol)

    @repeat_test_for_types(NO_HALF_TENSORTYPES)
    def test_gumbel_softmax(self, dtype=torch.float):
        """
        NO_HALF_TENSORTYPES because many half-ops doesnt work on cpu.
        """
        self._test_gumbel_softmax_st_shapes(cuda=False, dtype=dtype, shape=[5], dim=0, count_expected=1)
        self._test_gumbel_softmax_st_shapes(cuda=False, dtype=dtype, shape=[5], dim=-1, count_expected=1)
        self._test_gumbel_softmax_st_shapes(cuda=False, dtype=dtype, shape=[5, 4], dim=1, count_expected=5)
        self._test_gumbel_softmax_st_shapes(cuda=False, dtype=dtype, shape=[5, 4, 3], dim=1, count_expected=5 * 3)
        self._test_gumbel_softmax_st_shapes(cuda=False, dtype=dtype, shape=[5, 4, 3], dim=-1, count_expected=5 * 4)
        self._test_gumbel_softmax_straight_through(cuda=False, dtype=dtype)
        self._test_gumbel_softmax_grad(cuda=False, dtype=dtype)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_gumbel_softmax_cuda(self, dtype=torch.float):
        self._test_gumbel_softmax_st_shapes(cuda=True, dtype=dtype, shape=[5], dim=0, count_expected=1)
        self._test_gumbel_softmax_st_shapes(cuda=True, dtype=dtype, shape=[5], dim=-1, count_expected=1)
        self._test_gumbel_softmax_st_shapes(cuda=True, dtype=dtype, shape=[5, 4], dim=1, count_expected=5)
        self._test_gumbel_softmax_st_shapes(cuda=True, dtype=dtype, shape=[5, 4, 3], dim=1, count_expected=5 * 3)
        self._test_gumbel_softmax_st_shapes(cuda=True, dtype=dtype, shape=[5, 4, 3], dim=-1, count_expected=5 * 4)
        self._test_gumbel_softmax_straight_through(cuda=True, dtype=dtype)
        self._test_gumbel_softmax_grad(cuda=True, dtype=dtype)

    def _test_EmbeddingBag_vs_Embedding(self, N, D, B, L, max_norm=None,
                                        mode='mean',
                                        device='cpu',
                                        dtype=torch.float,
                                        test_per_sample_weights=False,
                                        trainable_per_sample_weights=False,
                                        sparse=False,
                                        test_backward=True,
                                        backward_prec=None):
        es = nn.EmbeddingBag(N, D, mode=mode, sparse=sparse, max_norm=max_norm).to(device, dtype)
        e = nn.Embedding(N, D, max_norm=max_norm).to(device, dtype)
        e.weight.data.copy_(es.weight)
        input = torch.randint(N, (B, L), device=device, dtype=torch.long)
        offsets = torch.arange(0, B, device=device, dtype=torch.long).mul_(L)
        grad_output = torch.rand(B, D, device=device, dtype=dtype)

        if test_per_sample_weights:
            # To prevent large gradients, weights should sum to 1 for each bag
            per_sample_weights = \
                torch.randn(B, L, device=device, dtype=dtype).softmax(dim=-1)
            per_sample_weights_reference = \
                per_sample_weights.clone().requires_grad_(trainable_per_sample_weights)
            per_sample_weights.requires_grad_(trainable_per_sample_weights)
            output = es(input.view(-1), offsets, per_sample_weights.view(-1))
        else:
            output = es(input.view(-1), offsets)
            per_sample_weights = None
            per_sample_weights_reference = None

        if mode == 'sum':
            if test_per_sample_weights:
                ref_output = (e(input) * per_sample_weights_reference.unsqueeze(-1)).sum(1)
            else:
                ref_output = e(input).sum(1)
        elif mode == 'mean':
            assert not test_per_sample_weights
            ref_output = e(input).mean(1)
        elif mode == 'max':
            assert not test_per_sample_weights
            ref_output = e(input).max(1)[0]

        self.assertEqual(output, ref_output, dtype2prec[dtype])

        if not test_backward:
            return

        output.backward(grad_output)
        ref_output.backward(grad_output)
        es_weight_grad = es.weight.grad.data
        if sparse:
            es_weight_grad = es.weight.grad.data.to_dense()

        # We have more floating point error here because we are dealing with larger numbers
        if backward_prec is None:
            needed_prec = dtype2prec[dtype] * 2
        else:
            needed_prec = backward_prec

        self.assertEqual(es_weight_grad, e.weight.grad, needed_prec)

        if test_per_sample_weights and trainable_per_sample_weights:
            self.assertEqual(per_sample_weights.grad, per_sample_weights_reference.grad,
                             dtype2prec[dtype])

    def _test_EmbeddingBag(self, cuda, mode, sparse, dtype=torch.double, test_backward=True):
        # check a known test example
        device = torch.device("cuda") if cuda else torch.device("cpu")
        es = nn.EmbeddingBag(5, 2, mode=mode, sparse=sparse).to(device, dtype)
        es.weight.data.copy_(torch.arange(1, 11, device=device, dtype=dtype).view_as(es.weight))
        input = torch.tensor([3, 1, 1, 1, 4, 0], device=device, dtype=torch.long)
        offsets = torch.tensor([0, 0, 3, 3, 6], device=device, dtype=torch.long)

        grad_output = torch.tensor(
            [1, 2,
             3, 4], device=device, dtype=dtype).view(2, 2)
        grad_output_with_empty = torch.tensor(
            [99, 99,
             1, 2,
             99, 99,
             3, 4,
             99, 99], device=device, dtype=dtype).view(5, 2)

        if mode == "sum" or mode == "mean":
            denominator = 1 if mode == "sum" else 3
            expected_output = torch.tensor(
                [[13, 16],
                 [13, 16]], device=device, dtype=dtype) / denominator

            expected_output_with_empty = torch.tensor(
                [[0, 0],
                 [13, 16],
                 [0, 0],
                 [13, 16],
                 [0, 0]], device=device, dtype=dtype) / denominator

            expected_grad_weight = torch.tensor(
                [[3, 4],
                 [5, 8],
                 [0, 0],
                 [1, 2],
                 [3, 4]], device=device, dtype=dtype) / denominator
        elif mode == "max":
            expected_output = torch.tensor(
                [[7, 8],
                 [9, 10]], device=device, dtype=dtype)

            expected_output_with_empty = torch.tensor(
                [[0, 0],
                 [7, 8],
                 [0, 0],
                 [9, 10],
                 [0, 0]], device=device, dtype=dtype)

            expected_grad_weight = torch.tensor(
                [[0, 0],
                 [0, 0],
                 [0, 0],
                 [1, 2],
                 [3, 4]], device=device, dtype=dtype)

        output = es(input, offsets)
        output.backward(grad_output_with_empty)

        es_weight_grad = es.weight.grad.data
        if sparse:
            es_weight_grad = es.weight.grad.to_dense()
        self.assertEqual(output, expected_output_with_empty)
        self.assertEqual(es_weight_grad, expected_grad_weight, dtype2prec[dtype])

        # check same example except as 2D (2 x 3)
        input = input.view(2, -1)
        es.zero_grad()
        output = es(input)
        output.backward(grad_output)

        es_weight_grad = es.weight.grad
        if sparse:
            es_weight_grad = es.weight.grad.to_dense()
        self.assertEqual(output, expected_output)
        self.assertEqual(es_weight_grad, expected_grad_weight, dtype2prec[dtype])

        # test all empty bags
        es.zero_grad()
        inputs = torch.tensor([], dtype=torch.long, device=device)
        offsets = torch.tensor([0, 0, 0, 0], device=device)
        es(inputs, offsets).sum().backward()
        dense_grad = es.weight.grad
        if dense_grad.is_sparse:
            dense_grad = dense_grad.to_dense()
        self.assertEqual(dense_grad, torch.zeros_like(es.weight))

        # now compare EmbeddingBag vs Embedding + Sum/Mean, for constant bag length
        N, D, B, L = random.randint(1, 100), random.randint(1, 100), random.randint(1, 50), random.randint(1, 50)
        kwargs = dict(mode=mode, sparse=sparse, device=device, dtype=dtype, test_backward=test_backward)
        self._test_EmbeddingBag_vs_Embedding(N, D, B, L, **kwargs)
        for max_norm in (None, 3):
            for p in itertools.product([1, 2], repeat=4):
                self._test_EmbeddingBag_vs_Embedding(*p, max_norm=max_norm, **kwargs)

        # check that giving illegal input combos raises error
        es = nn.EmbeddingBag(10, 20, mode=mode, sparse=sparse)
        input = torch.ones(3, 4)
        offset = torch.arange(0, 3)
        self.assertRaises(ValueError, lambda: es(input, offset))
        self.assertRaises(ValueError, lambda: es(input.view(-1)))
        offset[0] = 1
        self.assertRaises(ValueError, lambda: es(input.view(-1), offset))
        offset[0] = 0
        offset[-1] = 100
        self.assertRaises(ValueError, lambda: es(input.view(-1), offset))

    def test_embeddingbag_from_pretrained(self):
        a = torch.Tensor([[1, 2, 3], [4, 5, 6]])
        embeddingbag = nn.EmbeddingBag.from_pretrained(a)
        self.assertEqual(a, embeddingbag.weight.data)

        input = torch.LongTensor([[0, 1]])
        output = embeddingbag(input)
        self.assertEqual(a.mean(0, keepdim=True), output)

    def test_embeddingbag_from_pretrained_options(self):
        a = torch.Tensor([[1, 2, 3], [4, 5, 6]])
        opts = {
            "max_norm": 2.,
            "norm_type": .5,
            "scale_grad_by_freq": False,
            "mode": "max",
            "sparse": False
        }
        embeddingbag = nn.EmbeddingBag.from_pretrained(a, **opts)

        input = torch.LongTensor([[0, 1]])
        output = embeddingbag(input)
        self.assertEqual(a.max(0, keepdim=True)[0], output)
        self.assertTrue(a.ne(torch.arange(1, 7, dtype=a.dtype).view(2, 3)).all())
        self.assertTrue(a.norm(p=opts["norm_type"], dim=1).le(opts["max_norm"]).all())

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_pool3d_size_one_feature_dim(self):
        # Tests crazy strides for feature dim of size 1
        x = Variable(torch.randn(7, 1, 5, 3, 2, device="cuda"))
        strange_strides = [30, 1234, 6, 2, 1]
        y = x.as_strided(x.size(), strange_strides)
        x = x.cpu().as_strided(x.size(), strange_strides)

        to_test = {
            'max_pool3d': lambda t: F.max_pool3d(t, (5, 1, 1), stride=(5, 1, 1)),
            'avg_pool3d': lambda t: F.avg_pool3d(t, (5, 1, 1), stride=(5, 1, 1)),
        }

        for test, fn in to_test.items():
            # Should not crash
            out_y = fn(y)
            out_x = fn(x)
            self.assertEqual(out_y, out_x.cuda(), test)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_AvgPool3d_backward_after_cat_dim1_cuda(self):
        # x has to have batch_size 1 to test contiguous checks
        x = torch.randn(1, 3, 4, 4, 4, device="cuda", requires_grad=True)
        y = F.avg_pool3d(x, kernel_size=3, padding=1, stride=2)

        grad = torch.randn(y.size(), device="cuda")
        # increase the stride in dimension 0. the tensor is still contiguous because size[0] is 1
        stride = list(grad.stride())
        stride[0] = stride[0] * 2
        grad.set_(grad.storage(), 0, grad.size(), stride)
        assert grad.is_contiguous()

        y.backward(grad)

    @unittest.skipIf(not TEST_CUDNN, "needs cudnn")
    def test_contig_wrong_stride_cudnn(self):
        # x has to have batch_size 1 to test contiguous checks
        x = torch.randn(1, 16, 5, 5, device="cuda")
        stride = list(x.stride())
        stride[0] = 20
        # change the stride in dimension 0. the tensor is still contiguous because size[0] is 1
        x.set_(x.storage(), 0, x.size(), stride)
        self.assertTrue(x.is_contiguous())
        F.conv_transpose2d(x, torch.randn(16, 1, 1, 1, device="cuda"))
        F.conv2d(x, torch.randn(1, 16, 1, 1, device="cuda"))

    def test_embedding_bag(self):
        for dtype in [torch.double, torch.float]:
            self._test_EmbeddingBag(False, 'sum', False, dtype=dtype)
            self._test_EmbeddingBag(False, 'mean', False, dtype=dtype)
            self._test_EmbeddingBag(False, 'max', False, dtype=dtype)

            # TODO: figure out why precision on sparse embeddings isn't the
            # same as for dense.
            test_backward = dtype is not torch.float
            self._test_EmbeddingBag(False, 'sum', True, test_backward=test_backward, dtype=dtype)
            self._test_EmbeddingBag(False, 'mean', True, test_backward=test_backward, dtype=dtype)

    @staticmethod
    def _embedding_bag_reference_impl(input, weight, offsets=None, mode='sum',
                                      per_sample_weights=None):
        assert mode == 'sum'
        assert offsets is not None
        if per_sample_weights is None:
            per_sample_weights = torch.ones(input.size())
        assert input.numel() == per_sample_weights.numel()

        bags = []
        embeddings = weight.index_select(0, input) * per_sample_weights.unsqueeze(1)
        for index, offset in enumerate(offsets):
            if index + 1 < len(offsets):
                next_offset = offsets[index + 1]
            else:
                next_offset = len(input)
            length = next_offset - offset
            bags.append(embeddings.narrow(0, offset, length).sum(0))
        return torch.stack(bags)

    @staticmethod
    def _test_EmbeddingBag_per_sample_weights_failures(self, device='cpu'):
        # Failure 1: mismatched embeddings / per_sample_weights dtype
        es = nn.EmbeddingBag(5, 2, mode='sum').to(dtype=torch.float, device=device)
        input = torch.tensor([3, 1, 1, 1, 4, 0], dtype=torch.long, device=device)
        offsets = torch.tensor([0, 0, 3, 3, 6], dtype=torch.long, device=device)
        per_sample_weights = torch.randn_like(input, dtype=torch.double, device=device)
        if device == 'cpu':
            with self.assertRaisesRegex(RuntimeError, 'have the same type as'):
                es(input, offsets, per_sample_weights)
        else:
            with self.assertRaisesRegex(RuntimeError, 'expected scalar type'):
                es(input, offsets, per_sample_weights)

        # Failure 2.1: input/per_sample_weights have different sizes (1d input)
        input = torch.tensor([3, 1, 1, 1, 4, 0], dtype=torch.long, device=device)
        offsets = torch.tensor([0, 0, 3, 3, 6], dtype=torch.long, device=device)
        per_sample_weights = torch.randn(5, dtype=torch.float, device=device)
        with self.assertRaisesRegex(ValueError, 'same shape as the input'):
            es(input, offsets, per_sample_weights)

        # Failure 2.2: input/per_sample_weights have different sizes (2d input)
        input = torch.randint(5, (7, 3), dtype=torch.long, device=device)
        offsets = None
        per_sample_weights = torch.randn(7 * 3, dtype=torch.float, device=device)
        with self.assertRaisesRegex(ValueError, 'same shape as the input'):
            es(input, offsets, per_sample_weights)

        # Failure 3: Unsupported per_sample_weights and mode=('max', 'mean')
        for unsupported_mode in ('max', 'mean'):
            es = nn.EmbeddingBag(5, 2, mode=unsupported_mode).to(
                dtype=torch.float, device=device)
            input = torch.randint(5, (7, 3), dtype=torch.long, device=device)
            offsets = None
            per_sample_weights = torch.randn(7, 3, dtype=torch.float, device=device)
            with self.assertRaisesRegex(NotImplementedError,
                                        "only supported for mode='sum'"):
                es(input, offsets, per_sample_weights)

    def test_EmbeddingBag_per_sample_weights_failures(self):
        self._test_EmbeddingBag_per_sample_weights_failures(self)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_EmbeddingBag_per_sample_weights_failures_cuda(self):
        self._test_EmbeddingBag_per_sample_weights_failures(self, device='cuda')

    @staticmethod
    def _test_EmbeddingBag_per_sample_weights_and_offsets(self, device='cpu'):
        def test_per_sample_weights(mode, dtype, trainable_scale):
            es = nn.EmbeddingBag(5, 2, mode=mode).to(dtype=dtype, device=device)
            es.weight.data.copy_(
                torch.arange(1, 11, device=device, dtype=dtype).view_as(es.weight))
            input = torch.tensor([3, 1, 1, 1, 4, 0], device=device, dtype=torch.long)
            offsets = torch.tensor([0, 0, 3, 3, 6], device=device, dtype=torch.long)
            per_sample_weights = torch.randn_like(input, dtype=dtype) \
                                      .requires_grad_(trainable_scale)
            ref_per_sample_weights = \
                per_sample_weights.detach().requires_grad_(trainable_scale)
            reference_weights = es.weight.detach().requires_grad_()

            expected = self._embedding_bag_reference_impl(
                input, reference_weights, offsets, mode, ref_per_sample_weights)
            result = es(input, offsets, per_sample_weights)
            self.assertEqual(result, expected, prec=dtype2prec[dtype])

            grad = torch.randn_like(expected)
            result.backward(grad)
            expected.backward(grad)
            self.assertEqual(es.weight.grad, reference_weights.grad,
                             dtype2prec[dtype])
            if trainable_scale:
                self.assertEqual(per_sample_weights.grad, ref_per_sample_weights.grad,
                                 prec=dtype2prec[dtype])

        if device == 'cuda':
            dtypes = (torch.float, torch.double, torch.half)
        else:
            dtypes = (torch.float, torch.double)
        modes = ('sum',)
        trainable_scale = (True, False)
        for dtype, mode, trainable in itertools.product(dtypes, modes, trainable_scale):
            test_per_sample_weights(mode, dtype, trainable)

    def test_EmbeddingBag_per_sample_weights_and_offsets(self):
        self._test_EmbeddingBag_per_sample_weights_and_offsets(self)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_EmbeddingBag_per_sample_weights_and_offsets_cuda(self):
        self._test_EmbeddingBag_per_sample_weights_and_offsets(self, device='cuda')

    @staticmethod
    def _test_EmbeddingBag_per_sample_weights_and_no_offsets(self, device='cpu'):
        def run_tests(dtype, mode, sparse, trainable_per_sample_weights):
            kwargs = dict(test_per_sample_weights=True, device=device,
                          mode=mode, dtype=dtype, sparse=sparse,
                          trainable_per_sample_weights=trainable_per_sample_weights)

            # Simple case
            self._test_EmbeddingBag_vs_Embedding(2, 3, 5, 7, **kwargs)

            # B * L > 1000
            self._test_EmbeddingBag_vs_Embedding(2, 5, 53, 23, **kwargs)

            # Large num_embedding
            self._test_EmbeddingBag_vs_Embedding(101, 5, 3, 7, **kwargs)

            # Large embedding_dim
            self._test_EmbeddingBag_vs_Embedding(2, 101, 3, 7, **kwargs)

        dtypes = (torch.float, torch.double)
        modes = ('sum',)
        sparsity = (True, False)
        trainable_scale = (True, False)
        for dtype, mode, sparse, trainable_per_sample_weights in \
                itertools.product(dtypes, modes, sparsity, trainable_scale):
            run_tests(dtype, mode, sparse, trainable_per_sample_weights)

        # Test CUDA Dense on half precision
        if device == 'cuda':
            dtypes = (torch.half,)
            modes = ('sum',)
            sparsity = (False,)
            trainable_scale = (True, False)
            for dtype, mode, sparse, trainable_per_sample_weights in \
                    itertools.product(dtypes, modes, sparsity, trainable_scale):
                run_tests(dtype, mode, sparse, trainable_per_sample_weights)

    def test_EmbeddingBag_per_sample_weights_and_no_offsets(self):
        self._test_EmbeddingBag_per_sample_weights_and_no_offsets(self)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_EmbeddingBag_per_sample_weights_and_no_offsets_cuda(self):
        self._test_EmbeddingBag_per_sample_weights_and_no_offsets(self, device='cuda')

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_embedding_bag_cuda(self, dtype=torch.float):
        self._test_EmbeddingBag(True, 'sum', False, dtype)
        self._test_EmbeddingBag(True, 'mean', False, dtype)
        self._test_EmbeddingBag(True, 'max', False, dtype)

        # see 'todo' in test_embedding_bag.
        test_backward = dtype is not torch.float16
        self._test_EmbeddingBag(True, 'sum', True, dtype, test_backward=test_backward)
        self._test_EmbeddingBag(True, 'mean', True, dtype, test_backward=test_backward)

    def test_fractional_max_pool2d(self):
        x = torch.randn(1, 2, 7, 7, requires_grad=True)
        samples = x.new(1, 2, 2).uniform_()

        def func(x):
            return F.fractional_max_pool2d(
                x, (2, 2), output_size=(3, 3), _random_samples=samples)

        self.assertEqual(func(x).shape, (1, 2, 3, 3))
        gradcheck(func, [x])
        gradgradcheck(func, [x])

        x = torch.randn(2, 7, 7, requires_grad=True)
        samples = x.new(2, 2).uniform_()
        self.assertEqual(func(x).shape, (2, 3, 3))
        gradcheck(func, [x])
        gradgradcheck(func, [x])

    def test_Dropout(self):
        input = torch.Tensor(1000)
        self._test_dropout(nn.Dropout, False, input)

    def test_Dropout2d(self):
        b = random.randint(1, 5)
        w = random.randint(1, 5)
        h = random.randint(1, 5)
        num_features = 1000
        input = torch.Tensor(num_features, b, w, h)
        self._test_dropout(nn.Dropout2d, False, input)

    def test_Dropout3d(self):
        b = random.randint(1, 5)
        w = random.randint(1, 5)
        h = random.randint(1, 5)
        d = random.randint(1, 2)
        num_features = 1000
        input = torch.Tensor(num_features, b, d, w, h)
        self._test_dropout(nn.Dropout3d, False, input)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_Dropout_cuda(self):
        input = torch.Tensor(1000)
        self._test_dropout(nn.Dropout, True, input)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_Dropout2d_cuda(self):
        b = random.randint(1, 5)
        w = random.randint(1, 5)
        h = random.randint(1, 5)
        num_features = 1000
        input = torch.Tensor(num_features, b, w, h)
        self._test_dropout(nn.Dropout2d, True, input)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_Dropout3d_cuda(self):
        b = random.randint(1, 5)
        w = random.randint(1, 5)
        h = random.randint(1, 5)
        d = random.randint(1, 2)
        num_features = 1000
        input = torch.Tensor(num_features, b, d, w, h)
        self._test_dropout(nn.Dropout3d, True, input)

    def test_AlphaDropout(self):
        # generate random tensor with zero mean and unit std
        input = torch.randn(5000)
        self._test_alpha_dropout(nn.AlphaDropout, input)

    def test_FeatureAlphaDropout(self):
        b = random.randint(1, 5)
        w = random.randint(1, 5)
        h = random.randint(1, 5)
        d = random.randint(1, 2)
        num_features = 1000
        input = torch.randn(num_features, b, d, w, h)
        self._test_alpha_dropout(nn.FeatureAlphaDropout, input)

    def _test_InstanceNorm_general(self, cls, input, device="cpu", dtype=torch.float):
        # default case track_running_stats=False
        b, c = input.size(0), input.size(1)
        input_var = input.to(device=device, dtype=dtype).requires_grad_()

        IN = cls(c, eps=0).to(device, dtype)

        output = IN(input_var)
        out_reshaped = output.view(b * c, -1)

        mean = out_reshaped.mean(1)
        var = out_reshaped.var(1, unbiased=False)

        self.assertAlmostEqual(torch.abs(mean.data).mean(), 0, delta=1e-5)
        self.assertAlmostEqual(torch.abs(var.data).mean(), 1, delta=1e-5)

        # check that eval mode doesn't change behavior
        grad_out = torch.randn_like(output)
        res1 = output.data.clone()
        output.backward(grad_out)
        grad1 = input_var.grad.data.clone()

        IN.eval()
        output = IN(input_var)
        input_var.grad = None
        output.backward(grad_out)
        res2 = output.data
        grad2 = input_var.grad.data
        self.assertEqual(res1, res2)
        self.assertEqual(grad1, grad2)

        # If track_running_stats=True and momentum=1, running_mean/var should be
        # equal to mean/var of the input (with unbias correction)
        IN = cls(c, momentum=1, eps=0, track_running_stats=True).to(device, dtype)

        output = IN(input_var)

        input_reshaped = input_var.transpose(1, 0).reshape(c, -1)
        mean = input_reshaped.mean(1)

        input_reshaped = input_var.transpose(1, 0).reshape(c, b, -1)
        var = input_reshaped.var(2, unbiased=True)[:, :]

        self.assertAlmostEqual(torch.abs(mean.data - IN.running_mean).mean(), 0, delta=1e-5)
        self.assertAlmostEqual(torch.abs(var.data.mean(1) - IN.running_var).mean(), 0, delta=1e-5)

        # in eval mode, adding X * std to a channel in input should make the
        # corresponding channel in output have mean X
        IN.eval()
        delta = IN.running_var.sqrt() * torch.arange(c, device=device, dtype=dtype)
        delta = delta.view(-1, *[1 for _ in range(2, input.dim())])
        output = IN(input_var + delta)
        self.assertEqual(output.transpose(0, 1).reshape(c, -1).mean(1), torch.arange(c))

    def _test_InstanceNorm_cuda_half(self, cls, input):
        # THNN
        input = Variable(input.cuda().half().random_(1, 10), requires_grad=True)
        m = cls(input.size(1), affine=True, track_running_stats=True).to("cuda", torch.half)
        thnn_output = m(input)
        thnn_output.sum().backward()
        thnn_input_grad = input.grad.data.clone()
        self.assertEqual(thnn_output.type(), input.type())
        # cuDNN
        if TEST_CUDNN:
            input.grad = None
            m = m.float()
            cudnn_output = m(input)
            cudnn_output.sum().backward()
            cudnn_input_grad = input.grad.data.clone()
            self.assertEqual(cudnn_output.type(), input.type())
            self.assertAlmostEqual(cudnn_output, thnn_output, delta=1e-4)
            self.assertAlmostEqual(cudnn_input_grad, thnn_input_grad, delta=1e-3)

    def test_InstanceNorm1d_general(self):
        b = random.randint(3, 5)
        c = random.randint(3, 5)
        d = random.randint(8, 10)

        input = torch.rand(b, c, d)
        self._test_InstanceNorm_general(nn.InstanceNorm1d, input, dtype=torch.float)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_InstanceNorm1d_general_cuda(self):
        b = random.randint(3, 5)
        c = random.randint(3, 5)
        d = random.randint(8, 10)

        input = torch.rand(b, c, d)
        self._test_InstanceNorm_general(nn.InstanceNorm1d, input, "cuda", torch.float)
        self._test_InstanceNorm_cuda_half(nn.InstanceNorm1d, input)

    def test_InstanceNorm2d_general(self):
        b = random.randint(3, 5)
        c = random.randint(3, 5)
        w = random.randint(3, 6)
        h = random.randint(6, 8)

        input = torch.rand(b, c, h, w)
        self._test_InstanceNorm_general(nn.InstanceNorm2d, input, dtype=torch.float)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_InstanceNorm2d_general_cuda(self):
        b = random.randint(3, 5)
        c = random.randint(3, 5)
        w = random.randint(3, 6)
        h = random.randint(6, 8)

        input = torch.rand(b, c, h, w)
        self._test_InstanceNorm_general(nn.InstanceNorm2d, input, "cuda", torch.float)
        self._test_InstanceNorm_cuda_half(nn.InstanceNorm2d, input)

    def test_InstanceNorm3d_general(self):
        b = random.randint(3, 5)
        c = random.randint(3, 5)
        w = random.randint(2, 5)
        h = random.randint(2, 5)
        d = random.randint(2, 5)

        input = torch.rand(b, c, h, w, d)
        self._test_InstanceNorm_general(nn.InstanceNorm3d, input, dtype=torch.float)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @skipIfRocm
    def test_InstanceNorm3d_general_cuda(self):
        b = random.randint(3, 5)
        c = random.randint(2, 5)
        w = random.randint(2, 5)
        h = random.randint(2, 5)
        d = random.randint(2, 5)

        input = torch.rand(b, c, h, w, d)
        self._test_InstanceNorm_general(nn.InstanceNorm3d, input, "cuda", torch.float)
        self._test_InstanceNorm_cuda_half(nn.InstanceNorm3d, input)

    def _test_LayerNorm_general(self, device="cpu", dtype=torch.float):
        for i in range(2, 6):
            shape = torch.randint(3, 6, (i,), dtype=torch.long).tolist()
            x = torch.empty(*shape, device=device, dtype=dtype).uniform_(0, 10)
            normalized_ndim = random.randint(1, i - 1)  # inclusive
            normalized_shape = shape[-normalized_ndim:]
            unnormalized_shape = shape[:-normalized_ndim]

            # test that LN normalizes to mean 0 and stddev 1
            ln = nn.LayerNorm(normalized_shape, eps=0).to(device, dtype)
            ln.weight.data.fill_(1)
            ln.bias.data.fill_(0)
            output = ln(x)
            out_reshaped = output.view(*(unnormalized_shape + [-1]))
            mean = out_reshaped.mean(-1)
            var = out_reshaped.var(-1, unbiased=False)
            self.assertAlmostEqual(torch.abs(mean.data).mean(), 0, delta=1e-5)
            self.assertAlmostEqual(torch.abs(var.data).mean(), 1, delta=1e-5)

            # test that LN applies weight and bias correctly
            scale, bias = torch.empty(2).uniform_(0.2, 2).tolist()
            ln.weight.data.fill_(scale)
            ln.bias.data.fill_(bias)
            output = ln(x)
            out_reshaped = output.view(*(unnormalized_shape + [-1]))
            mean = out_reshaped.mean(-1)
            var = out_reshaped.var(-1, unbiased=False)
            self.assertAlmostEqual(torch.abs(mean.data).mean(), bias, delta=1e-5)
            self.assertAlmostEqual(torch.abs(var.data).mean(), scale ** 2, delta=1e-5)

        bad_norm_shape_input_shape = {
            (): (),
            (2, 3): (3,),
            (2,): (1, 2, 3),
            (10,): (2, 3),
            10: (2, 3),
        }
        for norm_shape, input_shape in bad_norm_shape_input_shape.items():
            ln = nn.LayerNorm(norm_shape)
            input = torch.empty(input_shape, device=device, dtype=dtype).uniform_(0, 10)
            self.assertRaises(RuntimeError, lambda: ln(input))

    def _test_LayerNorm_cuda_half(self):
        input = Variable(torch.empty(2, 3, 3, 2).to("cuda", torch.half).random_(1, 10), requires_grad=True)
        m = nn.LayerNorm([3, 2]).to("cuda", torch.half)
        output = m(input)
        output.sum().backward()
        self.assertEqual(output.type(), input.type())

    def test_LayerNorm_general(self):
        self._test_LayerNorm_general()

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_LayerNorm_general_cuda(self):
        self._test_LayerNorm_general("cuda")
        self._test_LayerNorm_cuda_half()

    def _test_GroupNorm_general(self, device="cpu", dtype=torch.float):
        good_shape_g = {
            (1, 2, 3, 4): 2,
            (2, 3, 10): 3,
            (3, 1, 1, 1, 2): 1,
            (2, 6, 4, 2, 2): 3,
        }
        for shape, g in good_shape_g.items():
            x = torch.empty(*shape, device=device, dtype=dtype).uniform_(0, 10)
            b = shape[0]
            c = shape[1]

            # test that GN normalizes to mean 0 and stddev 1
            gn = nn.GroupNorm(g, c, eps=0).to(device, dtype)
            gn.weight.data.fill_(1)
            gn.bias.data.fill_(0)
            output = gn(x)
            out_reshaped = output.view(b, g, -1)
            mean = out_reshaped.mean(-1)
            var = out_reshaped.var(-1, unbiased=False)
            self.assertAlmostEqual(torch.abs(mean).mean(), 0, delta=1e-5)
            self.assertAlmostEqual(torch.abs(var).mean(), 1, delta=1e-5)

            # test that GN applies weight and bias correctly
            scale = torch.empty(c, device=device, dtype=dtype).uniform_(0.2, 2)
            bias = torch.empty(c, device=device, dtype=dtype).uniform_(0.2, 2)
            gn.weight.data.copy_(scale)
            gn.bias.data.copy_(bias)
            output = gn(x)
            out_reshaped = output.view(b, c, -1)
            out_normed = (out_reshaped - bias.view(c, 1)) / scale.view(c, 1)
            out_normed_reshaped = out_normed.view(b, g, -1)
            mean = out_normed_reshaped.mean(-1)
            var = out_normed_reshaped.var(-1, unbiased=False)
            self.assertAlmostEqual(torch.abs(mean).mean(), 0, delta=1e-5)
            self.assertAlmostEqual(torch.abs(var).mean(), 1, delta=1e-5)

        bad_shape_g = {
            (1, 2, 3, 4): 3,
            (2, 3, 10): 2,
            (3, 1, 1, 1, 2): 10,
            (2, 6, 4, 2, 2): 4,
        }
        for shape, g in bad_shape_g.items():
            gn = nn.GroupNorm(g, shape[1])
            input = torch.empty(*shape, device=device, dtype=dtype).uniform_(0, 10)
            self.assertRaises(RuntimeError, lambda: gn(input))

    def _test_GroupNorm_cuda_half(self):
        input = Variable(torch.empty(2, 3, 3, 2).to("cuda", torch.half).random_(1, 10), requires_grad=True)
        input = torch.zeros(2, 4, 3, 2, requires_grad=True).cuda().half().random_(1, 10)
        m = nn.GroupNorm(2, 4).to("cuda", torch.half)
        output = m(input)
        output.sum().backward()
        self.assertEqual(output.type(), input.type())

    def test_GroupNorm_general(self):
        self._test_GroupNorm_general(dtype=torch.float)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_GroupNorm_general_cuda(self):
        self._test_GroupNorm_general("cuda", torch.float)
        self._test_GroupNorm_cuda_half()

    def test_pad(self):
        inputs = torch.randn(1, 3, 4, 4, requires_grad=True)
        _assertGradAndGradgradChecks(self, lambda x: F.pad(x, (1, 1, 1, 1)), (inputs,))
        _assertGradAndGradgradChecks(self, lambda x: F.pad(x, (-1, 1, -2, 1)), (inputs,))
        _assertGradAndGradgradChecks(self, lambda x: F.pad(x, (-1, 1, -2, 1), value=2), (inputs,))
        self.assertTrue(gradcheck(lambda x: F.pad(x, (-1, 1, -2, 1), mode='replicate'), (inputs,)))
        self.assertTrue(gradcheck(lambda x: F.pad(x, (-1, 1, -2, 1), mode='reflect'), (inputs,)))

        inputs = torch.randn(1, 2, 3, 4, 4, requires_grad=True)
        self.assertTrue(gradcheck(lambda x: F.pad(x, (1, 1, 1, 1, 1, 1), mode='replicate'), (inputs,)))

        # assert that relfection padding errors when pad >= input size
        expected_err_msg = r"Padding size should be less than the corresponding input dimension"
        self.assertRaisesRegex(RuntimeError, expected_err_msg,
                               lambda: F.pad(torch.randn(1, 1, 2, 3), (1, 1, 3, 0), mode='reflect'))
        self.assertRaisesRegex(RuntimeError, expected_err_msg,
                               lambda: F.pad(torch.randn(1, 1, 2), (2, 1), mode='reflect'))

    @staticmethod
    def _test_one_hot(self, use_cuda=False):
        device = torch.device('cuda' if use_cuda else 'cpu')
        with self.assertRaises(RuntimeError):
            torch.nn.functional.one_hot(torch.tensor([3, 4, -1, 0], device=device), -1)

        with self.assertRaises(RuntimeError):
            torch.nn.functional.one_hot(torch.tensor([3, 4, 1, 0], device=device), 3)

        t = torch.nn.functional.one_hot(torch.tensor([3, 4, 1, 0], device=device))
        expected = torch.tensor([[0, 0, 0, 1, 0],
                                 [0, 0, 0, 0, 1],
                                 [0, 1, 0, 0, 0],
                                 [1, 0, 0, 0, 0]], device=device)
        self.assertEqual(t, expected)

        t = torch.nn.functional.one_hot(torch.tensor([3, 4, 1, 0], device=device), -1)
        expected = torch.tensor([[0, 0, 0, 1, 0],
                                 [0, 0, 0, 0, 1],
                                 [0, 1, 0, 0, 0],
                                 [1, 0, 0, 0, 0]], device=device)
        self.assertEqual(t, expected)

        t = torch.nn.functional.one_hot(torch.tensor([3, 4, 1, 0], device=device), 6)
        expected = torch.tensor([[0, 0, 0, 1, 0, 0],
                                 [0, 0, 0, 0, 1, 0],
                                 [0, 1, 0, 0, 0, 0],
                                 [1, 0, 0, 0, 0, 0]], device=device)
        self.assertEqual(t, expected)

        t = torch.nn.functional.one_hot(torch.tensor([[3, 4], [1, 0]], device=device))
        expected = torch.tensor([[[0, 0, 0, 1, 0],
                                  [0, 0, 0, 0, 1]],
                                 [[0, 1, 0, 0, 0],
                                  [1, 0, 0, 0, 0]]], device=device)
        self.assertEqual(t, expected)

        t = torch.nn.functional.one_hot(torch.tensor(4, device=device))
        expected = torch.tensor([0, 0, 0, 0, 1], device=device)
        self.assertEqual(t, expected)

        t = torch.nn.functional.one_hot(torch.empty([4, 0], dtype=torch.long, device=device), 100)
        expected = torch.empty([4, 0, 100])
        self.assertEqual(t, expected)

        with self.assertRaises(RuntimeError):
            torch.nn.functional.one_hot(torch.empty([4, 0], dtype=torch.long, device=device))

        with self.assertRaises(RuntimeError):
            torch.nn.functional.one_hot(torch.tensor([3, 4, 1, 0], device=device), -2)

    def test_one_hot(self):
        self._test_one_hot(self)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_one_hot_cuda(self):
        self._test_one_hot(self, use_cuda=True)

    def test_pad_scalar_error(self):
        inputs = torch.tensor(0., requires_grad=True)
        self.assertRaises(AssertionError, lambda: F.pad(inputs, (1, 1)))
        self.assertRaises(AssertionError, lambda: F.pad(inputs, (1,)))

    def test_nn_scalars(self):
        # One off tests to ensure scalars from nn.yaml are properly applied
        def verify_scalars(input, output):
            if input.dim() == 0:
                self.assertEqual((), output.shape)
            else:
                self.assertNotEqual((), output.shape)
            output.sum().backward()
            self.assertEqual(input.shape, input.grad.shape)

        devices = ['cpu'] if not torch.cuda.is_available() else ['cpu', 'cuda']
        for device in devices:
            for input_shape in [(5, 6), ()]:
                for module in [torch.nn.ELU, torch.nn.Hardtanh, torch.nn.LeakyReLU, torch.nn.LogSigmoid,
                               torch.nn.RReLU, torch.nn.Softshrink, torch.nn.Softplus, torch.nn.Sigmoid,
                               torch.nn.Tanh]:
                    input = torch.randn(input_shape, device=device, requires_grad=True)
                    m = module()
                    output = m(input)
                    verify_scalars(input, output)

    def test_nn_scalars_reductions(self):
        # One off tests to ensure scalars from nn.yaml are properly applied
        def verify_reduction_scalars(input, reduction, output):
            if reduction != 'none' or input.dim() == 0:
                self.assertEqual((), output.shape)
            else:
                self.assertNotEqual((), output.shape)
            output.sum().backward()
            self.assertEqual(input.shape, input.grad.shape)

        devices = ['cpu'] if not torch.cuda.is_available() else ['cpu', 'cuda']
        for device in devices:
            for input_shape in [(5, 6), ()]:
                for reduction in ['none', 'mean', 'sum']:
                    for module in [torch.nn.BCELoss, torch.nn.L1Loss, torch.nn.MSELoss,
                                   torch.nn.SmoothL1Loss, torch.nn.SoftMarginLoss]:
                        input = torch.randn(input_shape, device=device, requires_grad=True)
                        target = torch.empty(input_shape, device=device).random_(2)
                        sigmoid = nn.Sigmoid()

                        input = torch.randn(input_shape, device=device, requires_grad=True)
                        m = module(reduction=reduction)
                        output = m(sigmoid(input), target)
                        verify_reduction_scalars(input, reduction, output)

    @unittest.skipIf((not TEST_NUMPY) or (not TEST_SCIPY) or (scipy.__version__ < '1.0.0'),
                     "Scipy v1.0 and/or numpy not found")
    def test_multihead_attention(self):
        def _scaled_dot_attn_ref(Q, K, V, dims, unseen_mask=None, src_lengths=None, 
                                 attn_mask=None, add_zero_attn=False):
            """ Numpy-based reference implementation of scaled dot attention
            for testing"""

            QKT = _batchmatmul(
                Q,
                np.transpose(K, axes=[0, 1, 3, 2])
                / np.sqrt(dims[3], dtype=np.float32),  # divide by sqrt(d_head)
            )
            b1, b2, s1, s2 = QKT.shape
            if unseen_mask is not None or src_lengths is not None:
                # assert s1 == s2
                for i in range(b1):
                    for j in range(b2):
                        for m in range(s1):
                            for n in range(s2):
                                if unseen_mask[m][n] == 0:
                                    QKT[i, j, m, n] = -np.inf
                                if src_lengths is not None and n >= src_lengths[i]:
                                    QKT[i, j, m, n] = -np.inf

            reference = _softmax(QKT)
            ref_attn_weight = reference
            ref_attn_weight = np.sum(ref_attn_weight, axis=1) / b2
            reference = _batchmatmul(reference, V)
            return reference, ref_attn_weight

        def _batchmatmul(a, b):  # batchmatmul over 4 dim matrix
            """ Numpy-based batch matrix multiply over 4 dim matrix"""
            assert a.shape[0] == b.shape[0]
            assert a.shape[1] == b.shape[1]
            retval = np.zeros(
                (a.shape[0], a.shape[1], a.shape[2], b.shape[3]), dtype=np.float32
            )
            for i in range(a.shape[0]):
                for j in range(a.shape[1]):
                    retval[i, j, :, :] = np.matmul(a[i, j, :, :], b[i, j, :, :])
            return retval

        def _softmax(x):  # softmax over 4 dim matrix
            """ Numpy-based reference softmax over 4 dim matrix"""
            np.seterr(invalid='ignore')
            output = np.zeros(x.shape, dtype=np.float64)
            for i in range(x.shape[0]):
                for j in range(x.shape[1]):
                    for k in range(x.shape[2]):
                        x_curr = x[i, j, k, :]
                        e_x = np.exp(x_curr - np.amax(x_curr))
                        output[i, j, k, :] = e_x / np.sum(e_x)
            return output

        def _generate_src_lengths(batch_size, seq_len):
            src_lengths = np.array([random.randint(1, seq_len) for i in range(batch_size)])

            # max source length has to equal seq_len, so randomly choose
            # one example to have source length = seq_len
            max_len_example_i = random.randint(0, batch_size - 1)
            src_lengths[max_len_example_i] = seq_len

            src_lengths_tensor = torch.from_numpy(src_lengths).int()
            return src_lengths, src_lengths_tensor

        def _split_heads_ref(X, dims, nheads, d_head):
            X_split = np.reshape(X, dims[:2] + [nheads, d_head])
            X_split_transposed = np.transpose(X_split, [0, 2, 1, 3])
            reference = np.reshape(X_split_transposed, [dims[0], nheads, dims[1], d_head])
            return reference

        def _combine_heads_ref(X, dims, nheads, d_head):
            X_transposed = np.transpose(X, [0, 2, 1, 3])
            reference = np.reshape(X_transposed, dims[:2] + [nheads * d_head])
            return reference

        def _fc(X, X_name, module, start=None, end=None):
            X_fc_b = None
            X_fc_w = None
            for name, param in module.named_parameters():
                if X_name + "weight" in name:
                    if X_fc_w is not None:
                        raise Exception("Duplicate FC name found")
                    X_fc_w = param[start:end, :].detach().numpy()
                elif X_name + "bias" in name:
                    if X_fc_b is not None:
                        raise Exception("Duplicate FC name found")
                    X_fc_b = param[start:end].detach().numpy()
            return np.matmul(X, np.transpose(X_fc_w)) + X_fc_b

        def _create_src_lengths_mask(batch_size, src_lengths):
            """
            Generate boolean mask to prevent attention beyond the end of source

            Inputs:
              batch_size : int
              src_lengths : [batch_size] of sentence lengths

            Outputs:
              [batch_size, max_src_len]
            """
            max_srclen = src_lengths.max()
            src_indices = torch.arange(0, max_srclen).unsqueeze(0).type_as(src_lengths)
            src_indices = src_indices.expand(batch_size, max_srclen)
            src_lengths = src_lengths.unsqueeze(dim=1).expand(batch_size, max_srclen)
            # returns [batch_size, max_seq_len]
            return (src_indices < src_lengths).int().detach()

        def _multihead_attn_test_helper(add_key_padding_mask, add_bias_kv=False, add_zero_attn=False):
            for _ in range(100):
                batch_sz, seq_len = [random.randint(2, 10) for r in range(2)]
                d_head = random.randint(3, 10)
                nheads = random.randint(3, 10)
                d_model = d_head * nheads
                dims = [batch_sz, seq_len, d_model]

                src_lengths = None
                src_lengths_tensor = None
                if add_key_padding_mask:
                    src_lengths, src_lengths_tensor = _generate_src_lengths(
                        batch_size=batch_sz, seq_len=seq_len
                    )

                decoder_state = np.random.rand(batch_sz, d_model).astype(np.float64)
                K = np.random.rand(*dims).astype(np.float64)
                V = K
                Q = np.expand_dims(decoder_state, 1)
                attn_mask = np.random.randint(0 , 2, size=(1, seq_len))
                attn_mask_tensor = torch.from_numpy(attn_mask).float()
                attn_mask_tensor.masked_fill_(attn_mask_tensor == 0, float('-inf'))
                attn_mask_tensor.masked_fill_(attn_mask_tensor > 0, float('0.0'))
                attn_mask_tensor = attn_mask_tensor.double()

                decoder_state_tensor = torch.from_numpy(decoder_state).double()
                source_hid_tensor = torch.from_numpy(K).double().transpose(0, 1)

                multihead_attn_module = MultiheadAttention(d_model, nheads, 
                                                           add_bias_kv=add_bias_kv,
                                                           add_zero_attn=add_zero_attn)

                if add_bias_kv:
                    bias_k = multihead_attn_module.bias_k.detach().numpy()
                    bias_v = multihead_attn_module.bias_v.detach().numpy()
                else:
                    bias_k = None
                    bias_v = None

                _batch_size = decoder_state_tensor.shape[0]
                _Q = decoder_state_tensor.unsqueeze(1).transpose(0, 1)
                _V = source_hid_tensor
                _K = source_hid_tensor
                src_len_mask = None
                if src_lengths is not None and add_key_padding_mask:
                    # [batch_size, 1, seq_len]
                    src_len_mask_int = _create_src_lengths_mask(
                        batch_size=_batch_size, src_lengths=src_lengths_tensor
                    )
                    src_len_mask = src_len_mask_int != 1

                result, result_weight = torch.nn.functional.multi_head_attention_forward(
                    _Q, _K, _V,
                    d_model, nheads,
                    multihead_attn_module.in_proj_weight, multihead_attn_module.in_proj_bias,
                    multihead_attn_module.bias_k, multihead_attn_module.bias_v,
                    multihead_attn_module.add_zero_attn, multihead_attn_module.dropout,
                    multihead_attn_module.out_proj.weight, multihead_attn_module.out_proj.bias,
                    multihead_attn_module.training, src_len_mask, True, attn_mask_tensor) 

                result = result.squeeze(0).detach().numpy()

                Q_fc = _fc(Q, "in_proj_", multihead_attn_module, end=d_model)
                K_fc = _fc(
                    K, "in_proj_", multihead_attn_module, start=d_model, end=2 * d_model
                )
                V_fc = _fc(V, "in_proj_", multihead_attn_module, start=2 * d_model)

                if add_bias_kv:
                    K_fc = np.concatenate((K_fc, np.repeat(bias_k, K_fc.shape[0], axis=0)), axis=1)
                    V_fc = np.concatenate((V_fc, np.repeat(bias_v, V_fc.shape[0], axis=0)), axis=1)
                    attn_mask = np.concatenate((attn_mask, np.ones([1, 1])), axis=1)
                    dims[1] += 1
                Q_split = _split_heads_ref(
                    Q_fc, [batch_sz, 1, d_model], nheads, d_head
                )
                K_split = _split_heads_ref(K_fc, dims, nheads, d_head)
                V_split = _split_heads_ref(V_fc, dims, nheads, d_head)

                if add_zero_attn:
                    dims[1] += 1
                    K_split = np.concatenate((K_split, np.zeros([K_split.shape[0], K_split.shape[1], 1, K_split.shape[3]])), axis=2)
                    V_split = np.concatenate((V_split, np.zeros([V_split.shape[0], V_split.shape[1], 1, V_split.shape[3]])), axis=2)
                    attn_mask = np.concatenate((attn_mask, np.ones([1, 1])), axis=1)

                attn_heads, ref_attn_weight = _scaled_dot_attn_ref(
                    Q=Q_split,
                    K=K_split,
                    V=V_split,
                    dims=Q_split.shape,
                    unseen_mask=attn_mask,
                    src_lengths=src_lengths
                )
                combined_attn_heads = _combine_heads_ref(
                    X=attn_heads, dims=[batch_sz, 1], nheads=nheads, d_head=d_head
                )

                reference = _fc(
                    combined_attn_heads, "out_proj.", multihead_attn_module
                )
                reference = np.squeeze(reference, axis=1)

                # result = reference
                self.assertEqual(tuple(result.shape), (batch_sz, d_model))
                np.testing.assert_allclose(result, reference, atol=1e-5)

                # result_weight = ref_attn_weight
                result_weight = result_weight.detach().numpy()
                self.assertEqual(tuple(result_weight.shape), tuple(ref_attn_weight.shape))
                np.testing.assert_allclose(result_weight, ref_attn_weight, atol=1e-5)

        def test_multihead_attn_add_bias_kv():
            _multihead_attn_test_helper(add_key_padding_mask=None, add_bias_kv=True)

        def test_multihead_attn_add_zero_attn():
            _multihead_attn_test_helper(add_key_padding_mask=None, add_zero_attn=True)

        def test_multihead_attn_no_masking():
            _multihead_attn_test_helper(add_key_padding_mask=None)

        def test_multihead_attn_key_padding_mask():
            _multihead_attn_test_helper(add_key_padding_mask=True)

        test_multihead_attn_add_zero_attn()  # Test MultiheadAttention with add_zero_attn
        test_multihead_attn_add_bias_kv()  # Test MultiheadAttention with add_bias_kv
        test_multihead_attn_no_masking()   # Test MultiheadAttention without masking
        test_multihead_attn_key_padding_mask()  # Test MultiheadAttention with src lengths

    def test_normalize(self):
        inputs = torch.randn(1, 3, 4, 4, requires_grad=True)
        self.assertTrue(gradcheck(lambda x: F.normalize(x, p=1, dim=-1), (inputs,)))
        self.assertTrue(gradcheck(lambda x: F.normalize(x, p=2, dim=-2), (inputs,)))

        inputs = torch.randn((), requires_grad=True)
        self.assertTrue(gradcheck(lambda x: F.normalize(x, p=1, dim=-1), (inputs,)))

    def _test_maxpool_indices(self, num_dim, adaptive=False, device="cpu", dtype=torch.float):
        def expected_indices(dim):
            if dim == 1:
                return torch.tensor([1, 3], dtype=torch.double).repeat(2, 2, 1)
            if dim == 2:
                return torch.tensor([[5, 7], [13, 15]], dtype=torch.double).repeat(2, 2, 1, 1)

        def expected_grad(dim):
            if dim == 1:
                return torch.tensor([0, 1, 0, 1], dtype=torch.double).repeat(2, 2, 1)
            grad = expected_grad(dim - 1)
            zero = torch.zeros(grad.size())
            return torch.stack((zero, grad, zero, grad), 2)

        def expected_output(dim):
            if dim == 1:
                return torch.arange(2, 17, 2).view(2, 2, 2)
            if dim == 2:
                col = torch.arange(6, 63, 8)
                return torch.stack([col, col + 2], 1).view(2, 2, 2, 2)

        if adaptive:
            cls_name = 'AdaptiveMaxPool{}d'.format(num_dim)
        else:
            cls_name = 'MaxPool{}d'.format(num_dim)
        module_cls = getattr(nn, cls_name)
        module = module_cls(2, return_indices=True).to(device, dtype=dtype)
        numel = 4 ** (num_dim + 1)
        input = torch.arange(1, numel + 1).view(2, 2, *repeat(4, num_dim)).to(device, dtype=dtype)
        input_var = input.clone().detach().requires_grad_()

        # Check forward
        output, indices = module(input_var)
        if num_dim != 3:
            expected_indices = expected_indices(num_dim)
            expected_output = expected_output(num_dim)
            self.assertEqual(indices.dim(), input.dim())
            self.assertEqual(indices.data.squeeze(), expected_indices)
            self.assertEqual(output.data.squeeze(), expected_output)
        self.assertTrue(output.requires_grad)
        self.assertFalse(indices.requires_grad)

        # Make sure backward works
        grad_output = torch.ones(output.size(), device=device, dtype=dtype)
        output.backward(grad_output, retain_graph=True)
        expected_grad = expected_grad(num_dim)
        self.assertEqual(input_var.grad.data, expected_grad.view_as(input))

        # Make sure backward after changing indices will result in an error
        indices.add_(1)
        self.assertRaises(RuntimeError, lambda: output.backward(grad_output))

    def test_adaptive_pooling_input_size(self):
        for numel in (2, 3):
            for pool_type in ('Max', 'Avg'):
                cls_name = 'Adaptive{}Pool{}d'.format(pool_type, numel)
                module_cls = getattr(nn, cls_name)
                output_size = (2,) * numel
                module = module_cls(output_size)

                input = torch.randn(output_size)
                self.assertRaises(ValueError, lambda: module(input))

    def test_adaptive_pooling_size_none(self):
        for numel in (2, 3):
            for pool_type in ('Max', 'Avg'):
                cls_name = 'Adaptive{}Pool{}d'.format(pool_type, numel)
                module_cls = getattr(nn, cls_name)
                output_size = (2,) * (numel - 1) + (None,)
                module = module_cls(output_size)

                input = torch.randn((4,) * (numel + 1))
                output = module(input)
                self.assertEqual(output.size(), (4,) + (2,) * (numel - 1) + (4,))

    def test_Conv2d_naive_groups(self):
        self._test_Conv2d_naive_groups()

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_Conv2d_naive_groups_cuda(self, dtype=torch.float):
        self._test_Conv2d_naive_groups("cuda", dtype)

    def test_batchnorm_grad(self):
        self._test_batchnorm_grad()

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @skipIfRocm
    def test_batchnorm_grad_cuda(self):
        self._test_batchnorm_grad("cuda")
        if TEST_CUDNN:
            with torch.backends.cudnn.flags(enabled=False):
                self._test_batchnorm_grad("cuda")

    def test_batchnorm_eval(self):
        self._test_batchnorm_eval()

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_batchnorm_eval_cuda(self, dtype=torch.float):
        self._test_batchnorm_eval("cuda", dtype)
        if TEST_CUDNN:
            with torch.backends.cudnn.flags(enabled=False):
                self._test_batchnorm_eval("cuda", dtype)

    def test_batchnorm_simple_average(self):
        self._test_batchnorm_simple_average()

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_batchnorm_simple_average_cuda(self):
        self._test_batchnorm_simple_average(torch.cuda.FloatTensor)
        if TEST_CUDNN:
            with torch.backends.cudnn.flags(enabled=False):
                self._test_batchnorm_simple_average(torch.cuda.FloatTensor)

    def test_MaxPool1d_indices(self):
        self._test_maxpool_indices(1)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_MaxPool1d_indices_cuda(self, dtype=torch.float):
        self._test_maxpool_indices(1, device="cuda", dtype=dtype)

    def test_MaxPool2d_indices(self):
        self._test_maxpool_indices(2)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_MaxPool2d_indices_cuda(self, dtype=torch.float):
        self._test_maxpool_indices(2, device="cuda", dtype=dtype)

    def test_MaxPool3d_indices(self):
        self._test_maxpool_indices(3)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_MaxPool3d_indices_cuda(self, dtype=torch.float):
        self._test_maxpool_indices(3, device="cuda", dtype=dtype)

    def test_AdaptiveMaxPool1d_indices(self):
        self._test_maxpool_indices(1, adaptive=True)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_AdaptiveMaxPool1d_indices_cuda(self, dtype=torch.float):
        self._test_maxpool_indices(1, adaptive=True, device="cuda", dtype=dtype)

    def test_AdaptiveMaxPool2d_indices(self):
        self._test_maxpool_indices(2, adaptive=True)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_AdaptiveMaxPool2d_indices_cuda(self, dtype=torch.float):
        self._test_maxpool_indices(2, adaptive=True, device="cuda", dtype=dtype)

    def test_AdaptiveMaxPool3d_indices(self):
        self._test_maxpool_indices(3, adaptive=True)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_AdaptiveMaxPool3d_indices_cuda(self, dtype=torch.float):
        self._test_maxpool_indices(3, adaptive=True, device="cuda", dtype=dtype)

    @staticmethod
    def _test_max_pool_nan(self, device, dtype=torch.float):
        for adaptive in ['', 'adaptive_']:
            for num_dim in [1, 2, 3]:
                fn_name = '{}max_pool{}d'.format(adaptive, num_dim)
                fn = getattr(F, fn_name)
                x = torch.full([1, 1] + num_dim * [3], nan)
                res = fn(x, 1 if adaptive else 3)
                self.assertTrue(math.isnan(res.item()))

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_max_pool_nan_cuda(self, dtype=torch.float):
        self._test_max_pool_nan(self, device="cuda", dtype=dtype)

    def test_max_pool_nan(self, dtype=torch.float):
        self._test_max_pool_nan(self, device="cpu")

    @staticmethod
    def _test_pool_large_size(self, device, dtype=torch.float):
        for op in ('max', 'avg'):
            for num_dim in [1, 2, 3]:
                fn_name = '{}_pool{}d'.format(op, num_dim)
                fn = getattr(F, fn_name)
                # 16777217 is the smallest integer not expressible in float32
                x = torch.ones([1, 1, 16777217] + (num_dim - 1) * [1],
                               device=device, dtype=dtype)
                res = fn(x, 1, stride=1, padding=0)
                # check if the output shape was still computed correctly
                self.assertEqual(x.shape[2], res.shape[2])

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_pool_large_size_cuda(self, dtype=torch.float):
        self._test_pool_large_size(self, device="cuda", dtype=dtype)

    def test_pool_large_size(self, dtype=torch.float):
        self._test_pool_large_size(self, device="cpu")

    def _test_scatter(self, tensor):
        x = tensor.detach().requires_grad_()
        result = dp.scatter(x, (0, 1))
        self.assertEqual(len(result), 2)
        self.assertEqual(result[0], x[:2])
        self.assertEqual(result[0].get_device(), 0)
        self.assertEqual(result[1], x[2:])
        self.assertEqual(result[1].get_device(), 1)
        grad = result[0].data.clone().fill_(2)
        result[0].backward(grad)
        self.assertEqual(x.grad.data[:2], grad)
        self.assertEqual(x.grad.data[2:], grad.clone().zero_())
        _assertGradAndGradgradChecks(self, lambda y: dp.scatter(y, (0, 1)), (x,))

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_scatter_cpu(self):
        self._test_scatter(torch.randn(4, 4))

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_scatter_gpu(self):
        self._test_scatter(torch.randn(4, 4).cuda())

    def _test_gather(self, output_device):
        inputs = (
            torch.randn(2, 4, device='cuda:0', requires_grad=True),
            torch.randn(2, 4, device='cuda:1', requires_grad=True),
        )
        result = dp.gather(inputs, output_device)
        self.assertEqual(result.size(), torch.Size([4, 4]))
        self.assertEqual(result[:2], inputs[0])
        self.assertEqual(result[2:], inputs[1])
        if output_device != -1:
            self.assertEqual(result.get_device(), output_device)
        else:
            self.assertFalse(result.is_cuda)
        grad = torch.randn(4, 4)
        if output_device != -1:
            grad = grad.cuda(output_device)
        result.backward(grad)
        self.assertEqual(inputs[0].grad.data, grad[:2])
        self.assertEqual(inputs[1].grad.data, grad[2:])
        _assertGradAndGradgradChecks(self, lambda x, y: dp.gather((x, y), output_device), inputs)

        # test scalar inputs, should stack into a vector in this case
        inputs = (
            torch.randn((), device='cuda:0', requires_grad=True),
            torch.randn((), device='cuda:1', requires_grad=True),
        )
        result = dp.gather(inputs, output_device)
        self.assertEqual(result.size(), torch.Size([2]))
        self.assertEqual(result[0], inputs[0])
        self.assertEqual(result[1], inputs[1])
        if output_device != -1:
            self.assertEqual(result.get_device(), output_device)
        else:
            self.assertFalse(result.is_cuda)
        grad = torch.randn(2)
        if output_device != -1:
            grad = grad.cuda(output_device)
        result.backward(grad)
        self.assertEqual(inputs[0].grad, grad[0])
        self.assertEqual(inputs[1].grad, grad[1])
        _assertGradAndGradgradChecks(self, lambda x, y: dp.gather((x, y), output_device), inputs)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    @skipIfRocm
    def test_gather_cpu(self):
        self._test_gather(-1)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_gather_gpu(self):
        self._test_gather(0)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_gather_different_len_dicts(self):
        inputs = (
            {'a': Variable(torch.randn(1, 2).cuda(0), requires_grad=True)},
            {
                'b': Variable(torch.randn(1, 2).cuda(1), requires_grad=True),
                'a': Variable(torch.randn(1, 2).cuda(1), requires_grad=True)
            }
        )
        with self.assertRaises(ValueError):
            _ = dp.gather(inputs, target_device=0)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_broadcast_double_backwards_gpu(self):
        tensors = (torch.randn(4, 4, device='cuda', requires_grad=True),
                   torch.randn(4, 4, device='cuda', requires_grad=True),
                   torch.randn(4, 4, device='cuda', requires_grad=True))
        _assertGradAndGradgradChecks(self, lambda *i: Broadcast.apply((0, 1), *i), tensors)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_broadcast_not_requiring_grad(self):
        variables = [
            torch.randn(1, 2, device='cuda', requires_grad=True),
            torch.randn(1, 2, device='cuda', requires_grad=False),
            torch.randn(1, 2, device='cuda', requires_grad=False),
            torch.randn(1, 2, device='cuda', requires_grad=True),
            torch.randn(1, 2, device='cuda', requires_grad=True),
        ]
        broadcasted_variables = Broadcast.apply((0, 1), *variables)
        for output_idx, broadcasted_var in enumerate(broadcasted_variables):
            input_var = variables[output_idx % len(variables)]
            self.assertEqual(input_var.requires_grad, broadcasted_var.requires_grad)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_broadcast_no_grad(self):
        x = torch.randn(1, 2, dtype=torch.float32, requires_grad=True, device='cuda')
        with torch.no_grad():
            broadcasted = Broadcast.apply((0, 1), x)
        self.assertTrue(x.requires_grad)
        for output in broadcasted:
            self.assertFalse(output.requires_grad)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_replicate(self):
        module = nn.Linear(10, 5).float().cuda()
        input = Variable(torch.randn(2, 10).float().cuda())
        expected_output = module(input).data
        for devices in [(0, 1), [0, 1]]:
            replicas = dp.replicate(module, devices)
            for i, replica in enumerate(replicas):
                for p in replica.parameters():
                    self.assertEqual(p.get_device(), i)
                replica_input = input.cuda(i)
                self.assertEqual(replica(replica_input).data, expected_output)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_replicate_buffers(self):
        net = nn.Module()
        net.bn = nn.BatchNorm2d(10)
        net.cuda()
        for devices in [(0, 1), [0, 1]]:
            replicas = dp.replicate(net, devices)
            for i, replica in enumerate(replicas):
                self.assertEqual(replica.bn.running_mean.get_device(), i, 'buffer on wrong device')
                self.assertEqual(replica.bn.running_var.get_device(), i, 'buffer on wrong device')
                self.assertEqual(replica.bn.num_batches_tracked.get_device(), i, 'buffer on wrong device')

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    @skipIfRocm
    def test_data_parallel_buffers_requiring_grad(self):
        class TestModule(nn.Module):
            def __init__(self, t):
                super(TestModule, self).__init__()
                self.register_buffer('t_rg', t)
                self.register_buffer('t_not_rg', t.clone().detach())

            def forward(self, x):
                return x * self.t_rg + self.t_not_rg

        m = TestModule(torch.randn(100, device='cuda', requires_grad=True))
        self.assertTrue(m.t_rg.requires_grad)

        dpm = nn.DataParallel(m, [0, 1])
        inp = torch.randn(2, 100, device='cuda')

        def fn(t):
            return dpm(inp)

        torch.autograd.gradcheck(fn, (m.t_rg,))

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_parallel_apply(self):
        l1 = nn.Linear(10, 5).to("cuda:0", torch.float)
        l2 = nn.Linear(10, 5).to("cuda:1", torch.float)
        i1 = torch.randn(2, 10, device="cuda:0", dtype=torch.float)
        i2 = torch.randn(2, 10, device="cuda:1", dtype=torch.float)
        expected1 = l1(i1).data
        expected2 = l2(i2).data
        modules = (l1, l2)
        expected_outputs = (expected1, expected2)

        # each input can be either a collection of positional arguments
        #                       or an object representing the single argument
        for inputs in [((i1,), (i2,)), (i1, i2)]:
            outputs = dp.parallel_apply(modules, inputs, None)
            for out, expected in zip(outputs, expected_outputs):
                self.assertEqual(out.data, expected)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel_multiple_input(self):
        class TestModule(nn.Module):

            def forward(self, var1, var2, float1, var3=None):
                if var3 is None:
                    return float1 * (var1 * var2)
                else:
                    return float1 * (var1 * var2 + var3)

        m = TestModule()
        var1 = torch.randn(5, 5, dtype=torch.float, requires_grad=True)
        var2 = torch.randn(5, 5, dtype=torch.float, requires_grad=True)
        var3 = torch.randn(5, 5, dtype=torch.float, requires_grad=False)

        float1 = torch.randn(1).item()

        expected = m(var1, var2, float1)
        loss = expected.sum()
        loss.backward()
        gvar1_exp = var1.grad.clone()
        gvar2_exp = var2.grad.clone()

        def local_test(out):
            var1.grad.data.fill_(0.0)
            var2.grad.data.fill_(0.0)
            loss = out.sum()
            loss.backward()
            self.assertEqual(out, expected)
            self.assertEqual(gvar1_exp, var1.grad)
            self.assertEqual(gvar2_exp, var2.grad)

        out = dp.data_parallel(m, (var1, var2, float1), (0, 1))
        local_test(out)

        out = dp.data_parallel(m, (var1, var2, float1), (1, 0))
        local_test(out)

        out = dp.data_parallel(m, (var1, var2, float1), (0,))
        local_test(out)

        var1.grad.data.fill_(0.0)
        var2.grad.data.fill_(0.0)
        expected = m(var1, var2, float1, var3=var3)
        loss = expected.sum()
        loss.backward()
        gvar1_exp = var1.grad.clone()
        gvar2_exp = var2.grad.clone()

        dpm = nn.DataParallel(TestModule())
        out = dpm(var1, var2, float1, var3=var3)
        local_test(out)

        dpm = nn.DataParallel(TestModule(), device_ids=[0])
        out = dpm(var1, var2, float1, var3=var3)
        local_test(out)

        kwarg_wrap = {'var3': var3}
        out = dp.data_parallel(
            m, (var1, var2, float1), (0, 1), module_kwargs=kwarg_wrap)
        local_test(out)

        out = dp.data_parallel(
            m, (var1, var2, float1), (0,), module_kwargs=kwarg_wrap)
        local_test(out)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel_small_back(self):
        l = nn.Linear(10, 5).float().cuda()
        i = Variable(torch.randn(20, 10).float().cuda())
        out = dp.data_parallel(l, i, (0, 1))
        self.assertEqual(out, l(i))

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel_model_device(self):
        r"""Test device[0] check at forward time.
        """
        l = nn.Linear(2, 2)
        inp = torch.randn(2, 2)
        inp_cuda0 = inp.cuda(0)
        inp_cuda1 = inp.cuda(1)

        error_msg = "module must have its parameters and buffers on device {}"

        @contextlib.contextmanager
        def dummy_ctx_manager():
            yield

        def test(inner_m, dp_device, inp, device_ids, should_fail):
            if device_ids is None:
                device_ids = list(range(torch.cuda.device_count()))

            if isinstance(device_ids[0], torch.device):
                expect_device = device_ids[0]
            else:
                expect_device = torch.device("cuda:{}".format(device_ids[0]))

            if should_fail:
                def assert_correct():
                    return self.assertRaisesRegex(RuntimeError, error_msg.format(expect_device))
            else:
                assert_correct = dummy_ctx_manager

            # test DataParallel module
            dpm = nn.DataParallel(inner_m, device_ids)
            if dp_device is not None:
                dpm = dpm.to(dp_device)

            with assert_correct():
                dpm(inp)

            # test functional
            with assert_correct():
                nn.parallel.data_parallel(inner_m.to(dp_device), inp, device_ids)

        test(l.to('cpu'), None, inp, None, should_fail=True)
        test(l.cuda(1), None, inp_cuda0, None, should_fail=True)
        test(l.cuda(), None, inp_cuda0, [1, 0], should_fail=True)

        test(l.cuda(), None, inp_cuda0, None, should_fail=False)
        test(l.cpu(), 'cuda', inp_cuda0, None, should_fail=False)
        test(l.cuda(1), None, inp_cuda1, [1, 0], should_fail=False)
        test(l.cpu(), 'cuda:1', inp_cuda1, [1, 0], should_fail=False)

        s = nn.Sequential(l.cpu())
        test(s, None, inp, None, should_fail=True)
        test(s, None, inp, [0, 1], should_fail=True)
        test(s, None, inp, [1, 0], should_fail=True)

        s = nn.Sequential(deepcopy(l).cpu(), l.cuda())
        test(s, None, inp, None, should_fail=True)
        test(s, None, inp, [0, 1], should_fail=True)
        test(s, None, inp, [1, 0], should_fail=True)

        s = nn.Sequential(l.cuda(), deepcopy(l).cuda(1))
        test(s, None, inp, None, should_fail=True)
        test(s, None, inp, [0, 1], should_fail=True)
        test(s, None, inp, [1, 0], should_fail=True)

        s = nn.Sequential(l.cuda(), deepcopy(l).cuda())
        test(s, None, inp, None, should_fail=False)
        test(s, None, inp, [0, 1], should_fail=False)
        test(s, None, inp, [1, 0], should_fail=True)
        test(s.cpu(), None, inp, [1, 0], should_fail=True)
        test(s.cuda(1), None, inp, [1, 0], should_fail=False)

    @unittest.skipIf(not TEST_MULTIGPU or not PY3, "multi-GPU not supported")
    @skipIfRocm
    def test_data_parallel_model_no_refcycles(self):
        # Python 2.7 will create reference cycles with the following
        # Module on multiple GPUs, but Python 3 shouldn't unless
        # there are refcycles on the PyTorch side (or the defined module)
        import gc

        class Model(nn.Module):
            def __init__(self):
                super(Model, self).__init__()
                self.linear = nn.Linear(1, 1)

            def forward(self, x):
                return self.linear(x)

        gc.collect()
        model = nn.DataParallel(Model().cuda())
        data = Variable(torch.randn(1).cuda())
        model(data)

        refcycles = gc.collect()
        self.assertEqual(refcycles, 0)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel_no_grad(self):
        test = self

        class Layer(nn.Module):
            def forward(self, x):
                test.assertFalse(torch.is_grad_enabled())
                return x

        l = Layer()
        i = Variable(torch.randn(20, 10).float().cuda())
        with torch.no_grad():
            dp.data_parallel(l, i, (0, 1))
        self.assertRaises(AssertionError, lambda: dp.data_parallel(l, i, (0, 1)))

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel(self):
        l = nn.Linear(10, 5).float().cuda()
        i = Variable(torch.randn(20, 10).float().cuda(1))
        l.cuda(1)
        expected_out = l(i)
        loss = expected_out.sum()
        loss.backward()
        expected_grads = []
        for param in l.parameters():
            expected_grads.append(param.grad.clone())
        dev_ids_list = [(0, 1), (1, 0)]
        for dev_id in dev_ids_list:
            with torch.cuda.device(dev_id[0]):
                l.cuda()
                l.zero_grad()
                out = dp.data_parallel(l, i, dev_id)
                loss = out.sum()
                loss.backward()
                self.assertEqual(out.get_device(), dev_id[0])
                self.assertEqual(out.data, expected_out.data)
                for expected, param in zip(expected_grads, l.parameters()):
                    self.assertEqual(param.grad.data, expected.data)

        # Check for None device_ids
        l = l.cuda()
        out = dp.data_parallel(l, i)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel_sparse(self):
        l = nn.Embedding(10, 5, sparse=True).to("cuda:1")
        i = torch.randint(10, (20, 5), device="cuda:1", dtype=torch.long)
        expected_out = l(i)
        loss = expected_out.sum()
        loss.backward()
        expected_grads = []
        for param in l.parameters():
            expected_grads.append(param.grad.clone())
        dev_ids_list = [(0, 1), (1, 0)]
        for dev_id in dev_ids_list:
            with torch.cuda.device(dev_id[0]):
                l.cuda()
                l.zero_grad()
                out = dp.data_parallel(l, i, dev_id)
                loss = out.sum()
                loss.backward()
                self.assertEqual(out.get_device(), dev_id[0])
                self.assertEqual(out.data, expected_out.data)
                for expected, param in zip(expected_grads, l.parameters()):
                    self.assertEqual(param.grad.data, expected.data)

        # Check for None device_ids
        l = l.cuda()
        out = dp.data_parallel(l, i)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel_nested_output(self):
        def fn(input):
            return [
                input, (input.sin(), input.cos(), [input.add(1)]), input,
                OrderedDict(a=input, b=[input.sin()])
            ]

        class Net(nn.Module):
            def forward(self, input):
                return fn(input)

        i = torch.randn(2, 2).float().cuda(1)
        gpus = range(torch.cuda.device_count())
        output = dp.data_parallel(Net(), i, gpus)
        self.assertEqual(output, fn(i))
        self.assertIsInstance(output[0], torch.Tensor)
        self.assertIsInstance(output[1], tuple)
        self.assertIsInstance(output[1][0], torch.Tensor)
        self.assertIsInstance(output[1][1], torch.Tensor)
        self.assertIsInstance(output[1][2], list)
        self.assertIsInstance(output[1][2][0], torch.Tensor)
        self.assertIsInstance(output[2], torch.Tensor)
        self.assertIsInstance(output[3], dict)
        self.assertEqual(len(output[3]), 2)
        self.assertIn('a', output[3])
        self.assertIn('b', output[3])
        self.assertIsInstance(output[3]['a'], torch.Tensor)
        self.assertIsInstance(output[3]['b'], list)
        self.assertIsInstance(output[3]['b'][0], torch.Tensor)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel_nested_input(self):
        def fn(input):
            return input[1][0]

        class Net(nn.Module):
            def forward(self, *input):
                return fn(input)

        i = Variable(torch.randn(20, 3).float().cuda(1))
        input = (i.cos(), (i.sin(), i), i.sin())
        gpus = range(torch.cuda.device_count())
        output = dp.data_parallel(Net(), input, gpus)
        self.assertEqual(output, fn(input))

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_data_parallel_module(self, dtype=torch.float):
        l = nn.Linear(10, 5).to("cuda", dtype)
        i = torch.randn(20, 10, device="cuda", dtype=dtype)
        expected_out = l(i).data
        net = nn.DataParallel(l)
        out = net(i)
        self.assertEqual(out.get_device(), 0)
        self.assertEqual(out.data, expected_out, dtype2prec[dtype])

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_data_parallel_module_kwargs_only(self, dtype=torch.float):
        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.l = l

            def forward(self, input):
                return self.l(input)

        l = nn.Linear(10, 5).to("cuda", dtype)
        i = torch.randn(20, 10, device="cuda", dtype=dtype)
        expected_out = l(i).data
        n = nn.DataParallel(Net())
        out = n(input=i)
        self.assertEqual(out.get_device(), 0)
        self.assertEqual(out.data, expected_out, dtype2prec[dtype])

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_data_parallel_module_kwargs_only_empty_list(self, dtype=torch.float):
        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.l = l

            def forward(self, input):
                return self.l(input['data'])

        l = nn.Linear(10, 5).to("cuda", dtype)
        i = torch.randn(20, 10, device="cuda", dtype=dtype)
        expected_out = l(i).data
        n = nn.DataParallel(Net())
        out = n(input={'data': i, 'unused': []})
        self.assertEqual(out.get_device(), 0)
        self.assertEqual(out.data, expected_out, dtype2prec[dtype])

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_data_parallel_module_kwargs_only_empty_dict(self, dtype=torch.float):
        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.l = l

            def forward(self, input):
                return self.l(input['data'])

        l = nn.Linear(10, 5).to("cuda", dtype)
        i = torch.randn(20, 10, device="cuda", dtype=dtype)
        expected_out = l(i).data
        n = nn.DataParallel(Net())
        out = n(input={'data': i, 'unused': {}})
        self.assertEqual(out.get_device(), 0)
        self.assertEqual(out.data, expected_out, dtype2prec[dtype])

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_data_parallel_module_kwargs_only_empty_tuple(self, dtype=torch.float):
        class Net(nn.Module):
            def __init__(self):
                super(Net, self).__init__()
                self.l = l

            def forward(self, input):
                return self.l(input['data'])

        l = nn.Linear(10, 5).to("cuda", dtype)
        i = torch.randn(20, 10, device="cuda", dtype=dtype)
        expected_out = l(i).data
        n = nn.DataParallel(Net())
        out = n(input={'data': i, 'unused': ()})
        self.assertEqual(out.get_device(), 0)
        self.assertEqual(out.data, expected_out, dtype2prec[dtype])

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_data_parallel_device_args(self):
        cuda0 = torch.device('cuda:0')
        cuda1 = torch.device('cuda:1')

        # test output_device
        l = nn.Linear(10, 5).to(cuda0, torch.float)
        i = torch.randn(20, 10, dtype=torch.float, device=cuda0, requires_grad=True)
        out = dp.data_parallel(l, i, device_ids=(0, 1), output_device=cuda0)
        self.assertEqual(out, l(i))

        # test device_ids
        l = nn.Linear(10, 5).to(cuda0, torch.float)
        i = torch.randn(20, 10, dtype=torch.float, device=cuda0, requires_grad=True)
        out = dp.data_parallel(l, i, device_ids=(cuda0, cuda1), output_device=cuda0)
        self.assertEqual(out, l(i))

    def test_state_dict(self):
        l = nn.Linear(5, 5)
        block = nn.Module()
        block.conv = nn.Conv2d(3, 3, 3, bias=False)
        net = nn.Module()
        net.linear1 = l
        net.linear2 = l
        net.bn = nn.BatchNorm2d(2)
        net.block = block
        net.add_module('empty', None)

        state_dict = net.state_dict()
        self.assertEqual(len(state_dict), 10)
        self.assertEqual(len(state_dict._metadata), 6)
        self.assertIn('', state_dict._metadata)
        self.assertIn('linear1', state_dict._metadata)
        self.assertIn('linear1.weight', state_dict)
        self.assertIn('linear1.bias', state_dict)
        self.assertIn('linear2', state_dict._metadata)
        self.assertIn('linear2.weight', state_dict)
        self.assertIn('linear2.bias', state_dict)
        self.assertIn('block', state_dict._metadata)
        self.assertIn('block.conv', state_dict._metadata)
        self.assertIn('block.conv.weight', state_dict)
        self.assertIn('block.conv.weight', state_dict)
        self.assertNotIn('block.conv.bias', state_dict)
        self.assertIn('bn', state_dict._metadata)
        self.assertIn('bn.weight', state_dict)
        self.assertIn('bn.bias', state_dict)
        self.assertIn('bn.running_var', state_dict)
        self.assertIn('bn.running_mean', state_dict)
        self.assertIn('bn.num_batches_tracked', state_dict)
        self.assertFalse(any(map(lambda k: k.startswith('empty'), state_dict.keys())))
        for k, v in state_dict.items():
            param = net
            for component in k.split('.'):
                param = getattr(param, component)
                if isinstance(param, Parameter):
                    param = param.data
            self.assertEqual(v.data_ptr(), param.data_ptr())

        l = nn.Linear(5, 5)
        state_dict = l.state_dict()
        self.assertEqual(len(state_dict), 2)
        self.assertEqual(len(state_dict._metadata), 1)
        self.assertIn('', state_dict._metadata)
        self.assertTrue(state_dict._metadata['']['version'] >= 0)
        self.assertEqual(state_dict['weight'].data_ptr(), l.weight.data_ptr())
        self.assertEqual(state_dict['bias'].data_ptr(), l.bias.data_ptr())

    def test_load_state_dict(self):
        l = nn.Linear(5, 5)
        block = nn.Module()
        block.conv1 = nn.Conv2d(3, 3, 3, bias=True)
        block.conv2 = nn.Conv2d(3, 3, 3, bias=False)
        net = nn.Module()
        net.linear1 = l
        net.linear2 = l
        net.bn = nn.BatchNorm2d(2)
        net.block = block
        net.add_module('empty', None)

        state_dict = net.state_dict()
        state_dict.update({
            'linear1.weight': torch.ones(5, 5),
            'block.conv1.bias': torch.arange(1, 4),
            'bn.running_mean': torch.randn(2),
        })
        incompatible_keys = net.load_state_dict(state_dict)
        self.assertEqual(len(incompatible_keys.missing_keys), 0)
        self.assertEqual(len(incompatible_keys.unexpected_keys), 0)
        self.assertEqual(net.linear1.weight.data, state_dict['linear1.weight'])
        self.assertEqual(net.block.conv1.bias.data, state_dict['block.conv1.bias'])
        self.assertEqual(net.bn.running_mean, state_dict['bn.running_mean'])

        state_dict = net.state_dict()
        state_dict.update({'extra': torch.ones(5)})
        self.assertRaises(RuntimeError, lambda: net.load_state_dict(state_dict))
        incompatible_keys = net.load_state_dict(state_dict, strict=False)
        self.assertEqual(len(incompatible_keys.missing_keys), 0)
        self.assertEqual(len(incompatible_keys.unexpected_keys), 1)
        self.assertIn('extra', incompatible_keys.unexpected_keys)

        state_dict = net.state_dict()
        state_dict.update({'extra.param': torch.ones(5)})
        self.assertRaises(RuntimeError, lambda: net.load_state_dict(state_dict))
        incompatible_keys = net.load_state_dict(state_dict, strict=False)
        self.assertEqual(len(incompatible_keys.missing_keys), 0)
        self.assertEqual(len(incompatible_keys.unexpected_keys), 1)
        self.assertIn('extra.param', incompatible_keys.unexpected_keys)

        state_dict = net.state_dict()
        del state_dict['linear1.weight']
        self.assertRaises(RuntimeError, lambda: net.load_state_dict(state_dict))
        incompatible_keys = net.load_state_dict(state_dict, strict=False)
        self.assertEqual(len(incompatible_keys.missing_keys), 1)
        self.assertEqual(len(incompatible_keys.unexpected_keys), 0)
        self.assertIn('linear1.weight', incompatible_keys.missing_keys)
        state_dict.update({'extra.param': torch.ones(5)})
        self.assertRaises(RuntimeError, lambda: net.load_state_dict(state_dict))
        incompatible_keys = net.load_state_dict(state_dict, strict=False)
        self.assertEqual(len(incompatible_keys.missing_keys), 1)
        self.assertEqual(len(incompatible_keys.unexpected_keys), 1)
        self.assertIn('linear1.weight', incompatible_keys.missing_keys)
        self.assertIn('extra.param', incompatible_keys.unexpected_keys)

        state_dict = net.state_dict()
        state_dict.update({'bn.running_mean': torch.rand(14, 4)})  # wrong size
        self.assertRaises(RuntimeError, lambda: net.load_state_dict(state_dict))
        self.assertRaises(RuntimeError, lambda: net.load_state_dict(state_dict, strict=False))

        state_dict = net.state_dict()
        old_state_dict = deepcopy(state_dict)
        state_dict = {
            'linear1.weight': torch.ones(5, 5),
            'block.conv1.bias': torch.arange(1, 4),
            'bn.running_mean': torch.randn(2),
            'nonexistent_key': torch.rand(3)
        }
        net.load_state_dict(state_dict, strict=False)
        self.assertEqual(net.linear1.weight.data, state_dict['linear1.weight'])
        self.assertEqual(net.block.conv1.bias.data, state_dict['block.conv1.bias'])
        self.assertEqual(net.bn.running_mean, state_dict['bn.running_mean'])
        new_state_dict = net.state_dict()
        del old_state_dict['linear1.weight']
        del old_state_dict['block.conv1.bias']
        del old_state_dict['bn.running_mean']
        for k, v, in old_state_dict.items():
            self.assertTrue(v.equal(new_state_dict[k]))

    def test_load_state_dict_BC(self):
        # BatchNormNd
        # Added num_batches_tracked buffer at version 2. For state dict with
        # earlier versions or no versions, it should provide default value of 0.
        bn = nn.BatchNorm2d(3)
        state_dict = bn.state_dict()
        del state_dict['num_batches_tracked']
        state_dict._metadata['']['version'] = 1  # version 1
        bn.load_state_dict(state_dict)
        self.assertEqual(bn.num_batches_tracked.dtype, torch.long)
        self.assertEqual(bn.num_batches_tracked.item(), 0)
        del state_dict._metadata['']['version']  # no version
        bn.load_state_dict(state_dict)
        self.assertEqual(bn.num_batches_tracked.dtype, torch.long)
        self.assertEqual(bn.num_batches_tracked.item(), 0)

    @unittest.skipIf(not PY3, 'Python 2.7 generates cyclic trash')
    def test_load_state_dict_ref_cycle(self):
        # load_state_dict shouldn't cause a reference cycle involving Tensors
        import gc

        m = torch.nn.LSTM(16, 16, bidirectional=True)

        gc.collect()
        m.load_state_dict(deepcopy(m).state_dict())
        refcycles = gc.collect()

        self.assertEqual(refcycles, 0)

    def test_parameter_assignment(self):
        l = nn.Linear(5, 5)

        def num_params():
            return len(list(l.parameters()))

        self.assertEqual(num_params(), 2)

        new_param = Parameter(torch.randn(5, 5))
        l.param_name = new_param
        self.assertEqual(num_params(), 3)
        self.assertObjectIn(new_param, l.parameters())

        var = torch.randn(5, 5)
        l.var_name = var
        self.assertEqual(num_params(), 3)
        self.assertNotIn(id(var), map(id, l.parameters()))

        # Make sure Variables are not saved as parameters
        l.variable_attr = torch.empty(5, 5)
        self.assertEqual(num_params(), 3)
        l.param_attr = Parameter(torch.empty(5, 5))
        self.assertEqual(num_params(), 4)

        # It shouldn't be possible to replace a parameter with a Variable
        def assign_var():
            l.param_attr = torch.empty(5, 5)

        self.assertRaises(TypeError, assign_var)
        # But replacing it with None should be fine
        l.param_attr = None
        self.assertEqual(num_params(), 3)

    def test_assignment(self):
        l = nn.Module()
        a = nn.Parameter(torch.randn(2))
        b = nn.Parameter(torch.randn(3))
        c = nn.Parameter(torch.randn(4))
        q = nn.Linear(4, 4)
        r = nn.Linear(5, 5)
        w = nn.Linear(6, 6)

        def test_assignments(get_list, a, b, c):
            # Check that None can be shadowed
            l.a = None
            self.assertIsNone(l.a)
            self.assertIn('a', l.__dict__)
            l.a = a
            self.assertIs(l.a, a)
            self.assertEqual(get_list(), [a])
            self.assertNotIn('a', l.__dict__)

            # Assign second object
            l.b = None
            self.assertIsNone(l.b)
            self.assertIn('b', l.__dict__)
            l.b = b
            self.assertIs(l.b, b)
            self.assertEqual(get_list(), [a, b])
            self.assertNotIn('b', l.__dict__)

            # Remove and add the object back. Order should be unchanged.
            l.a = None
            self.assertIsNone(l.a)
            self.assertEqual(get_list(), [b])
            l.a = a
            self.assertIs(l.a, a)
            self.assertEqual(get_list(), [a, b])

            # Replace object with another one. Order should be unchanged.
            l.a = c
            self.assertIs(l.a, c)
            self.assertEqual(get_list(), [c, b])

            # Remove and reassign an attribute. It should appear at the end of the list now.
            del l.a
            self.assertFalse(hasattr(l, 'a'))
            l.a = a
            self.assertIs(l.a, a)
            self.assertEqual(get_list(), [b, a])

        test_assignments(lambda: list(l.parameters()), a, b, c)
        del l.a, l.b
        self.assertEqual(list(l.parameters()), [])

        test_assignments(lambda: list(l.children()), q, r, w)
        del l.a, l.b
        self.assertEqual(list(l.children()), [])

        buf = torch.randn(10)
        l.register_buffer('buf', buf)
        self.assertIs(l.buf, buf)
        l.buf = None
        self.assertIs(l.buf, None)
        self.assertNotIn('buf', l.__dict__)  # should be stored in l._buffers
        l.buf = buf
        self.assertIn('buf', l.state_dict())
        self.assertEqual(l.state_dict()['buf'], buf)

    def test_Conv2d_inconsistent_types(self):
        inputs = Variable(torch.randn(4, 1, 7, 7).float())
        weights = Variable(torch.randn(1, 1, 3, 3).double())
        # inconsistent types should raise an exception
        self.assertRaises(RuntimeError, lambda: nn.functional.conv2d(inputs, weights))
        # but it should work with the same type
        nn.functional.conv2d(inputs.float(), weights.float())

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    def test_Conv2d_inconsistent_types_on_GPU_without_cudnn(self):
        inputs = Variable(torch.randn(4, 1, 7, 7).float().cuda())
        weights = Variable(torch.randn(1, 1, 3, 3).double().cuda())
        bias = Variable(torch.randn(1).double().cuda())

        with torch.backends.cudnn.flags(enabled=False):
            # inconsistent types should raise an exception
            self.assertRaises(RuntimeError, lambda: nn.functional.conv2d(inputs, weights))
            self.assertRaises(RuntimeError, lambda: nn.functional.conv2d(inputs, weights.float(), bias))

            # but it should work with the same type
            nn.functional.conv2d(inputs.float(), weights.float(), bias.float())

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @unittest.skipIf(not TEST_CUDNN, 'CUDNN not available')
    def test_Conv2d_inconsistent_types_on_GPU_with_cudnn(self):
        inputs = Variable(torch.randn(4, 1, 7, 7).float().cuda())
        weights = Variable(torch.randn(1, 1, 3, 3).double().cuda())
        bias = Variable(torch.randn(1).double().cuda())

        with torch.backends.cudnn.flags(enabled=True):
            # inconsistent types should raise an exception
            self.assertRaises(RuntimeError, lambda: nn.functional.conv2d(inputs, weights))
            self.assertRaises(RuntimeError, lambda: nn.functional.conv2d(inputs, weights.float(), bias))

            # but it should work with the same type
            nn.functional.conv2d(inputs.float(), weights.float(), bias.float())

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @unittest.skipIf(not TEST_CUDNN, 'CUDNN not available')
    @skipIfRocm
    def test_cudnn_multiple_threads_same_device(self):
        # This function is intended to test the lazy creation and reuse of per-thread
        # cudnn handles on each device in aten/src/ATen/cudnn/Handles.cpp.
        # Failure here likely indicates something wrong with that logic.
        weight = torch.ones((1, 1, 2, 2), device='cuda')

        results = {}

        num_threads = 2
        trials = 2
        test_iters = 100

        with torch.backends.cudnn.flags(enabled=True):
            def _worker(t, input):
                my_stream = torch.cuda.Stream()
                results[t] = input
                with torch.cuda.stream(my_stream):
                    for _ in range(test_iters):
                        # If all threads are sharing the same cudnn handle,
                        # the following sequence may occur:
                        # thread 0 calls setCuDNNStreamToCurrent()
                        # thread 1 calls setCuDNNStreamToCurrent()
                        # thread 0 launches its raw convolution, which it thinks is in
                        #          its own stream, but is actually in thread 1's stream.
                        # thread 0 enqueues its div_, which IS is its own stream,
                        #          but now races with its convolution.
                        results[t] = torch.nn.functional.conv2d(results[t], weight, padding=0)
                        results[t].div_(4.0)
                torch.cuda.current_stream().wait_stream(my_stream)

            for _ in range(trials):
                for t in range(num_threads):
                    results[t] = torch.ones((1, 1, 2048, 2048), device='cuda')

                threads = [threading.Thread(target=_worker,
                                            args=(t, results[t])) for t in range(num_threads)]

                for thread in threads:
                    thread.start()
                for thread in threads:
                    thread.join()

                for t in range(num_threads):
                    self.assertEqual(results[t].sum().item(),
                                     (2048 - test_iters) * (2048 - test_iters))

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @unittest.skipIf(not TEST_CUDNN, 'CUDNN not available')
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_Conv2d_deterministic_cudnn(self, dtype=torch.float):
        inputs = torch.randn(2, 3, 5, 5, device="cuda", dtype=dtype, requires_grad=True)
        with cudnn.flags(enabled=True, benchmark=True, deterministic=True):
            conv1 = torch.nn.Conv2d(3, 3, 3).to("cuda", dtype)
            conv2 = torch.nn.Conv2d(3, 3, 3).to("cuda", dtype)
            conv2.bias.data.copy_(conv1.bias.data)
            conv2.weight.data.copy_(conv1.weight.data)
            out1 = conv1(inputs)
            out2 = conv2(inputs)
            self.assertEqual(out1, out2, prec=0.0)
            y = torch.randn(out1.size(), device="cuda", dtype=dtype)
            out1.backward(y)
            out2.backward(y)
            self.assertEqual(conv1.bias.grad.data, conv2.bias.grad.data, prec=0.0)
            self.assertEqual(conv1.weight.grad.data, conv2.weight.grad.data, prec=0.0)

    def test_Conv2d_missing_argument(self):
        c = nn.Conv2d(3, 3, 3)
        self.assertRaises(TypeError, lambda: c(None))

    def test_Conv2d_backward_twice(self):
        input = torch.randn(2, 3, 5, 5)
        c = nn.Conv2d(3, 3, 3)
        o1 = c(input)
        o1.sum().backward()
        self.assertRaisesRegex(RuntimeError, 'Specify retain_graph=True',
                               lambda: o1.sum().backward())

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_Conv2d_large_workspace(self, dtype=torch.float):
        # These sizes require huge cuDNN workspaces. Make sure we choose a
        # reasonable algorithm that does not run out of memory
        sizes = [
            (1, 256, 109, 175),
            (1, 256, 80, 128),
            (1, 256, 120, 192),
        ]

        def run_test(benchmark):
            with torch.backends.cudnn.flags(benchmark=benchmark):
                conv = torch.nn.Conv2d(256, 256, kernel_size=3, padding=1).to("cuda", dtype)
                for size in sizes:
                    x = torch.randn(size, device="cuda", dtype=dtype)
                    out = conv(x.detach().clone().requires_grad_())
                    out.backward(torch.ones_like(out))

        run_test(benchmark=False)
        run_test(benchmark=True)

    def test_conv_modules_raise_error_on_incorrect_input_size(self):
        modules = [nn.Conv1d(3, 8, 3), nn.ConvTranspose1d(3, 8, 3),
                   nn.Conv2d(3, 8, 3), nn.ConvTranspose2d(3, 8, 3),
                   nn.Conv3d(3, 8, 3), nn.ConvTranspose3d(3, 8, 3)]

        invalid_input_dims = [(2, 4), (2, 4),
                              (3, 5), (3, 5),
                              (4, 6), (4, 6)]

        for invalid_dims, module in zip(invalid_input_dims, modules):
            for dims in invalid_dims:
                input = torch.empty(torch.Size((3, ) * dims))
                self.assertRaises(RuntimeError, lambda: module(input))

    def test_conv_shapecheck(self):
        def test(should_raise, module, input_size):
            input = torch.empty(3, *input_size)
            if should_raise:
                self.assertRaises(RuntimeError, lambda: module(input))
            else:
                # just run it to ensure no exception raised.
                module(input)

        # Conv1d
        test(True, nn.Conv1d(1, 1, 3), (1, 2))
        test(True, nn.Conv1d(1, 1, 3, stride=2), (1, 2))
        test(False, nn.Conv1d(1, 1, 2), (1, 2))
        test(False, nn.Conv1d(1, 1, 2, stride=2), (1, 2))
        test(False, nn.Conv1d(1, 1, 3, stride=2, padding=1), (1, 2))

        # Conv2d
        test(True, nn.Conv2d(1, 1, (3, 3)), (1, 2, 2))
        test(False, nn.Conv2d(1, 1, (3, 3)), (1, 3, 3))
        test(False, nn.Conv2d(1, 1, (3, 3), padding=1), (1, 2, 2))

        # Conv3D
        test(True, nn.Conv3d(1, 1, (3, 3, 3)), (1, 2, 2, 2))
        test(False, nn.Conv3d(1, 1, (3, 3, 3)), (1, 3, 3, 3))
        test(False, nn.Conv3d(1, 1, (3, 3, 3), padding=1), (1, 2, 2, 2))

    def test_ConvTranspose2d_output_size(self):
        m = nn.ConvTranspose2d(3, 4, 3, 3, 0, 2)
        i = torch.randn(2, 3, 6, 6)
        for h in range(15, 22):
            for w in range(15, 22):
                if 18 <= h <= 20 and 18 <= w <= 20:
                    output = m(i, output_size=(h, w))
                    self.assertEqual(output.size()[2:], (h, w))
                else:
                    self.assertRaises(ValueError, lambda: m(i, (h, w)))

    def test_ConvTranspose3d_correct_output_size(self):
        # Check that ConvTranspose3d can take a 5d output_size.
        m = nn.ConvTranspose3d(2, 2, 2)
        i = torch.rand(1, 2, 1, 1, 1)
        out = m(i, output_size=(1, 2, 2, 2, 2))

    def _test_Conv2d_naive_groups(self, device="cpu", dtype=torch.float):
        # Check that grouped convolutions matches two half convolutions
        m = nn.Conv2d(4, 4, kernel_size=3, groups=2).to(device, dtype)
        i = torch.randn(2, 4, 6, 6, device=device, dtype=dtype, requires_grad=True)
        output = m(i)
        grad_output = torch.randn(2, 4, 4, 4, device=device, dtype=dtype)
        output.backward(grad_output)

        m1 = nn.Conv2d(2, 2, kernel_size=3).to(device, dtype)
        m1.weight.data.copy_(m.weight.data[:2])
        m1.bias.data.copy_(m.bias.data[:2])
        i1 = Variable(i.data[:, :2].contiguous(), requires_grad=True)
        output1 = m1(i1)
        output1.backward(grad_output[:, :2].contiguous())

        m2 = nn.Conv2d(2, 2, kernel_size=3).to(device, dtype)
        m2.weight.data.copy_(m.weight.data[2:])
        m2.bias.data.copy_(m.bias.data[2:])
        i2 = Variable(i.data[:, 2:].contiguous(), requires_grad=True)
        output2 = m2(i2)
        output2.backward(grad_output[:, 2:].contiguous())

        self.assertEqual(output, torch.cat([output1, output2], 1))
        self.assertEqual(i.grad.data,
                         torch.cat([i1.grad.data, i2.grad.data], 1),
                         prec=dtype2prec[dtype])
        self.assertEqual(m.bias.grad.data,
                         torch.cat([m1.bias.grad.data, m2.bias.grad.data], 0),
                         prec=dtype2prec[dtype])
        self.assertEqual(m.weight.grad.data,
                         torch.cat([m1.weight.grad.data, m2.weight.grad.data], 0),
                         prec=dtype2prec[dtype])

    # For https://github.com/pytorch/pytorch/pull/1273
    # Almost identical to the above `test_Conv2d_naive_groups`
    def test_Conv2d_groups_nobias(self):
        dev_dtypes = [("cpu", torch.float)]
        if TEST_CUDA:
            dev_dtypes += [("cuda", torch.float), ("cuda", torch.half)]
        for device, dtype in dev_dtypes:
            m = nn.Conv2d(4, 4, kernel_size=3, groups=2, bias=False).to(device, dtype)
            i = torch.randn(2, 4, 6, 6, device=device, dtype=dtype, requires_grad=True)
            output = m(i)
            grad_output = torch.randn(2, 4, 4, 4, device=device, dtype=dtype)
            output.backward(grad_output)

            m1 = nn.Conv2d(2, 2, kernel_size=3, bias=False).to(device, dtype)
            m1.weight.data.copy_(m.weight.data[:2])
            i1 = Variable(i.data[:, :2].contiguous(), requires_grad=True)
            output1 = m1(i1)
            output1.backward(grad_output[:, :2].contiguous())

            m2 = nn.Conv2d(2, 2, kernel_size=3, bias=False).to(device, dtype)
            m2.weight.data.copy_(m.weight.data[2:])
            i2 = Variable(i.data[:, 2:].contiguous(), requires_grad=True)
            output2 = m2(i2)
            output2.backward(grad_output[:, 2:].contiguous())

            self.assertEqual(output, torch.cat([output1, output2], 1))
            self.assertEqual(i.grad.data,
                             torch.cat([i1.grad.data, i2.grad.data], 1),
                             dtype2prec[dtype])
            self.assertEqual(m.weight.grad.data,
                             torch.cat([m1.weight.grad.data, m2.weight.grad.data], 0),
                             1e-1 if dtype == torch.half else dtype2prec[dtype])

    # Very similar to test_Conv2d_naive_groups but with special care to handle
    # the number of groups == number of input channels
    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_Conv2d_depthwise_naive_groups_cuda(self, dtype=torch.float):
        for depth_multiplier in [1, 2]:
            m = nn.Conv2d(2, 2 * depth_multiplier, kernel_size=3, groups=2).to("cuda", dtype)
            i = torch.randn(2, 2, 6, 6, device="cuda", dtype=dtype).div_(2).requires_grad_()
            output = m(i)
            grad_output = torch.randn(2, 2 * depth_multiplier, 4, 4, device="cuda", dtype=dtype) / 2
            output.backward(grad_output)

            offset = 1 * depth_multiplier

            m1 = nn.Conv2d(1, 1 * depth_multiplier, kernel_size=3).to("cuda", dtype)
            m1.weight.data = m.weight.data[:offset].clone()
            m1.bias.data = m.bias.data[:offset].clone()
            i1 = i.detach()[:, :1].clone().requires_grad_()
            output1 = m1(i1)
            output1.backward(grad_output[:, :offset].contiguous())

            m2 = nn.Conv2d(1, 1 * depth_multiplier, kernel_size=3).to("cuda", dtype)
            m2.weight.data.copy_(m.weight.data[offset:])
            m2.bias.data.copy_(m.bias.data[offset:])
            i2 = i.detach()[:, 1:].clone().requires_grad_()
            output2 = m2(i2)
            output2.backward(grad_output[:, offset:].contiguous())

            self.assertEqual(output, torch.cat([output1, output2], 1),
                             prec=dtype2prec[dtype])
            self.assertEqual(i.grad.data,
                             torch.cat([i1.grad.data, i2.grad.data], 1),
                             prec=dtype2prec[dtype])
            self.assertEqual(m.bias.grad.data,
                             torch.cat([m1.bias.grad.data,
                                        m2.bias.grad.data], 0),
                             prec=dtype2prec[dtype])
            self.assertEqual(m.weight.grad.data,
                             torch.cat([m1.weight.grad.data,
                                        m2.weight.grad.data], 0),
                             prec=dtype2prec[dtype])

    def test_MaxUnpool2d_output_size(self):
        m = nn.MaxPool2d(3, stride=2, return_indices=True)
        mu = nn.MaxUnpool2d(3, stride=2)
        big_t = torch.rand(1, 1, 6, 6)
        big_t[0][0][4][4] = 100
        output_big, indices_big = m(big_t)
        self.assertRaises(RuntimeError, lambda: mu(output_big, indices_big))

        small_t = torch.rand(1, 1, 5, 5)
        for i in range(0, 4, 2):
            for j in range(0, 4, 2):
                small_t[:, :, i, j] = 100
        output_small, indices_small = m(Variable(small_t))
        for h in range(3, 10):
            for w in range(3, 10):
                if 4 <= h <= 6 and 4 <= w <= 6:
                    size = (h, w)
                    if h == 6:
                        size = (1, 1) + size

                    mu(output_small, indices_small, output_size=size)
                else:
                    self.assertRaises(ValueError, lambda: mu(output_small, indices_small, (h, w)))

    def test_container_copy(self):
        class Model(nn.Module):
            def __init__(self):
                super(Model, self).__init__()
                self.linear = nn.Linear(4, 5)

            def forward(self, input):
                return self.linear(input)

        input = torch.randn(2, 4)

        model = Model()
        model_cp = deepcopy(model)
        self.assertEqual(model(input).data, model_cp(input).data)

        model_cp.linear.weight.data[:] = 2
        self.assertNotEqual(model(input).data, model_cp(input).data)

    def test_RNN_cell(self):
        # this is just a smoke test; these modules are implemented through
        # autograd so no Jacobian test is needed
        for module in (nn.RNNCell, nn.GRUCell):
            for bias in (True, False):
                input = torch.randn(3, 10)
                hx = torch.randn(3, 20)
                cell = module(10, 20, bias=bias)
                for _ in range(6):
                    hx = cell(input, hx)

                hx.sum().backward()

    def _test_loss_equal_input_target_shape(self, cast):
        # Tests losses whose inputs should have the same size.
        losses = {
            'mse_loss': lambda x, y: F.mse_loss(x, y),
            'l1_loss': lambda x, y: F.l1_loss(x, y),
            'smooth_l1_loss': lambda x, y: F.smooth_l1_loss(x, y),
            'kl_div': lambda x, y: F.kl_div(x, y),
            'poisson_nll_loss': lambda x, y: F.poisson_nll_loss(x, y),
        }

        input = Variable(cast(torch.randn(3, 5)))
        target = Variable(cast(torch.randn(5, 3)))
        for _name, fn in losses.items():
            self.assertRaises(Exception, lambda: fn(input, target))

    def test_loss_equal_input_target_shape(self):
        self._test_loss_equal_input_target_shape(lambda x: x)

    def test_mse_loss_size_warning(self):
        i = torch.randn((10, 1), requires_grad=True)
        t = torch.randn((10,))
        with warnings.catch_warnings(record=True) as w:
            # Ensure warnings are being shown
            warnings.simplefilter("always")
            # Trigger Warning
            F.mse_loss(i, t)
            # Check warning occurs
            self.assertEqual(len(w), 1)
            self.assertIn('Please ensure they have the same size.', str(w[0]))

    def test_nll_loss_mismatched_batch(self):
        x = torch.randn((10, 3), requires_grad=True)
        # t should have size (10,)
        t = torch.zeros((3,), dtype=torch.int64)
        with self.assertRaisesRegex(ValueError, 'Expected.*batch_size'):
            F.nll_loss(x, t)

    def test_nll_loss_out_of_bounds_ignore_index(self):
        x = torch.randn(6, 3, requires_grad=True)
        t = torch.tensor([0, 1, 255, 0, 1, 2], dtype=torch.int64)
        for reduction in ['mean', 'none']:
            F.nll_loss(x, t, ignore_index=255, reduction=reduction).sum().backward()

    def test_poisson_nll_loss_reduction_modes(self):
        input = torch.tensor([0.5, 1.5, 2.5])
        target = torch.tensor([1., 2., 3.])
        component_wise_loss = torch.exp(input) - target * input
        self.assertEqual(component_wise_loss,
                         F.poisson_nll_loss(input, target, reduction='none'))
        self.assertEqual(torch.sum(component_wise_loss),
                         F.poisson_nll_loss(input, target, reduction='sum'))
        self.assertEqual(torch.mean(component_wise_loss),
                         F.poisson_nll_loss(input, target, reduction='mean'))
        with self.assertRaisesRegex(ValueError, 'is not valid'):
            F.poisson_nll_loss(input, target, reduction='total')

    def test_KLDivLoss_batch_mean(self):
        input_shape = (2, 5)
        log_prob1 = F.log_softmax(torch.randn(input_shape), 1)
        prob2 = F.softmax(torch.randn(input_shape), 1)

        loss = nn.KLDivLoss(reduction='batchmean')
        l = loss(log_prob1, prob2)

        loss_none_reduce = nn.KLDivLoss(reduction='sum')(log_prob1, prob2)
        expected = loss_none_reduce / input_shape[0]

        self.assertEqual(l, expected)

    @unittest.skipIf(not (TEST_CUDNN and TEST_CUDNN_VERSION >= 7000), "needs cudnn >= 7.0")
    def test_CTCLoss_cudnn(self):
        target_lengths = [30, 25, 20]
        input_lengths = [50, 50, 50]
        targets = torch.randint(1, 15, (sum(target_lengths),), dtype=torch.int)
        log_probs = torch.randn(50, 3, 15, dtype=torch.float, device='cuda').log_softmax(2)
        res = torch.nn.functional.ctc_loss(log_probs, targets, input_lengths, target_lengths)
        expected = ctcloss_reference(log_probs, targets.cuda(), input_lengths, target_lengths).float()
        with torch.backends.cudnn.flags(enabled=False):
            res2 = torch.nn.functional.ctc_loss(log_probs, targets.cuda().long(), input_lengths, target_lengths)
        self.assertEqual(res, expected)
        self.assertEqual(res2, res)

    def test_CTCLoss_typechecks(self):
        target_lengths = torch.tensor([30, 25, 20])
        input_lengths = torch.tensor([50, 50, 50])
        targets = torch.randint(1, 15, (sum(target_lengths),), dtype=torch.int)
        log_probs = torch.randn(50, 3, 15, dtype=torch.float).log_softmax(2)
        with self.assertRaises(RuntimeError):
            _input_lengths = input_lengths.to(dtype=torch.float)
            torch.nn.functional.ctc_loss(log_probs, targets, _input_lengths, target_lengths)
        with self.assertRaises(RuntimeError):
            target_lengths = target_lengths.to(dtype=torch.float)
            torch.nn.functional.ctc_loss(log_probs, targets, input_lengths, target_lengths)

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    def test_CTCLoss_lengthchecks_cuda(self):
        target_lengths = [30, 25, 20]
        input_lengths = [50, 50, 50]
        targets = torch.randint(1, 15, (3, 29), dtype=torch.long, device='cuda')
        log_probs = torch.randn(50, 3, 15, dtype=torch.float, device='cuda').log_softmax(2)
        with self.assertRaises(RuntimeError):
            torch.nn.functional.ctc_loss(log_probs, targets, input_lengths, target_lengths)

    def test_CTCLoss_lengthchecks_cpu(self):
        target_lengths = [30, 25, 20]
        input_lengths = [50, 50, 50]
        targets = torch.randint(1, 15, (3, 29), dtype=torch.int)
        log_probs = torch.randn(50, 3, 15, dtype=torch.float).log_softmax(2)
        with self.assertRaises(RuntimeError):
            torch.nn.functional.ctc_loss(log_probs, targets, input_lengths, target_lengths)

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    def test_CTCLoss_zero_infinity(self):
        target_lengths = [60, 25, 20]
        input_lengths = [50, 50, 50]
        targets = torch.randint(1, 15, (sum(target_lengths),), dtype=torch.int, device='cuda')
        log_probs = torch.randn(50, 3, 15, dtype=torch.float, device='cuda').log_softmax(2).requires_grad_()
        res = torch.nn.functional.ctc_loss(log_probs, targets, input_lengths, target_lengths,
                                           reduction='sum', zero_infinity=True)
        with torch.backends.cudnn.flags(enabled=False):
            res2 = torch.nn.functional.ctc_loss(log_probs, targets.cuda().long(), input_lengths, target_lengths,
                                                reduction='sum', zero_infinity=True)
        res_cpu = torch.nn.functional.ctc_loss(log_probs.cpu(), targets.cpu(), input_lengths, target_lengths,
                                               reduction='sum', zero_infinity=True)

        self.assertAlmostEqual(res2, res, delta=1e-4)
        self.assertAlmostEqual(res_cpu, res.cpu(), delta=1e-4)
        g1, = torch.autograd.grad(res, log_probs)
        g2, = torch.autograd.grad(res2, log_probs)
        g3, = torch.autograd.grad(res_cpu, log_probs)
        self.assertAlmostEqual(g2, g3, delta=1e-4)
        self.assertAlmostEqual(g1, g2, delta=1e-4)
        self.assertTrue((g1 == g1).all().item())  # check that we don't have NaN

    def test_RNN_cell_no_broadcasting(self):
        def test(cell_module, input, hx, input_size, hidden_size):
            cell = cell_module(input_size, hidden_size)
            self.assertRaises(RuntimeError, lambda: cell(input, hx))

        def test_all(hidden_size, bad_hx, good_hx, input_size, input):
            test(nn.RNNCell, input, bad_hx, input_size, hidden_size)
            test(nn.GRUCell, input, bad_hx, input_size, hidden_size)
            test(nn.LSTMCell, input, (bad_hx, good_hx), input_size, hidden_size)
            test(nn.LSTMCell, input, (good_hx, bad_hx), input_size, hidden_size)

        hidden_size = 20
        input_size = 10
        input = torch.randn(3, input_size)
        bad_hx = torch.randn(1, hidden_size)
        good_hx = torch.randn(3, hidden_size)

        # Test hidden/input batch size broadcasting
        test_all(hidden_size, bad_hx, good_hx, input_size, input)

        # Test hx's hidden_size vs module's hidden_size broadcasting
        bad_hx = torch.randn(3, 1)
        test_all(hidden_size, bad_hx, good_hx, input_size, input)

        # Test input's input_size vs module's input_size broadcasting
        bad_input = torch.randn(3, 1)
        test_all(hidden_size, good_hx, good_hx, input_size, bad_input)

    def test_invalid_dropout_p(self):
        v = torch.ones(1)
        self.assertRaises(ValueError, lambda: nn.Dropout(-0.1))
        self.assertRaises(ValueError, lambda: nn.Dropout(1.1))
        self.assertRaises(ValueError, lambda: nn.Dropout2d(-0.1))
        self.assertRaises(ValueError, lambda: nn.Dropout2d(1.1))
        self.assertRaises(ValueError, lambda: nn.Dropout3d(-0.1))
        self.assertRaises(ValueError, lambda: nn.Dropout3d(1.1))
        self.assertRaises(ValueError, lambda: F.dropout(v, -0.1))
        self.assertRaises(ValueError, lambda: F.dropout(v, 1.1))

    def test_empty_dropout(self):
        x = torch.Tensor([])
        out = torch.nn.functional.dropout(x)
        self.assertEqual(out.size(), x.size())

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    def test_empty_dropout_cuda(self):
        x = torch.Tensor([]).to('cuda')
        out = torch.nn.functional.dropout(x)
        self.assertEqual(out.size(), x.size())

    def test_pad_sequence(self):
        def pad(tensor, length):
            return torch.cat(
                [tensor.data, tensor.data.new(
                    length - tensor.size(0), *tensor.size()[1:]).zero_()])

        # single dimensional
        a = torch.tensor([1, 2, 3])
        b = torch.tensor([4, 5])
        c = torch.tensor([6])

        # batch_first = true
        expected = torch.tensor([[4, 5, 0], [1, 2, 3], [6, 0, 0]])
        padded = rnn_utils.pad_sequence([b, a, c], True)
        self.assertEqual(padded, expected)

        # batch_first = false
        padded = rnn_utils.pad_sequence([b, a, c])
        self.assertEqual(padded, expected.transpose(0, 1))

        # pad with non-zero value
        expected = torch.tensor([[4, 5, 1], [1, 2, 3], [6, 1, 1]])
        padded = rnn_utils.pad_sequence([b, a, c], True, 1)
        self.assertEqual(padded, expected)

        # Test pad sorted sequence
        expected = torch.tensor([[1, 2, 3], [4, 5, 0], [6, 0, 0]])
        padded = rnn_utils.pad_sequence([a, b, c], True)
        self.assertEqual(padded, expected)

        # more dimensions
        maxlen = 9
        for num_dim in (0, 1, 2, 3):
            sequences = []
            trailing_dims = [4] * num_dim
            for i in range(1, maxlen + 1):
                seq_len = i * i
                sequences.append(torch.rand(seq_len, 5, *trailing_dims))
            random.shuffle(sequences)
            expected = []
            for seq in sequences:
                expected.append(pad(seq, maxlen * maxlen))
            # batch first = true
            expected = torch.stack(expected)
            padded = rnn_utils.pad_sequence(sequences, True)
            self.assertEqual(padded, expected)

            # batch first = false
            padded = rnn_utils.pad_sequence(sequences)
            self.assertEqual(padded, expected.transpose(0, 1))

    def test_pack_sequence(self):
        def _compatibility_test(sequences, lengths, batch_first, enforce_sorted=False):
            padded = rnn_utils.pad_sequence(sequences, batch_first)
            packed = rnn_utils.pack_sequence(sequences, enforce_sorted)
            unpacked = rnn_utils.pad_packed_sequence(packed, batch_first)
            self.assertEqual(padded, unpacked[0])
            pack_padded = rnn_utils.pack_padded_sequence(
                padded, lengths, batch_first, enforce_sorted)
            self.assertEqual(packed, pack_padded)

        # single dimensional
        a = torch.tensor([1, 2, 3])
        b = torch.tensor([4, 5])
        c = torch.tensor([6])
        packed = rnn_utils.pack_sequence([a, b, c], enforce_sorted=False)
        expected = torch.tensor([1, 4, 6, 2, 5, 3])
        self.assertEqual(packed.batch_sizes, [3, 2, 1])
        self.assertEqual(packed.data.data, expected)
        self.assertEqual(packed.sorted_indices, [0, 1, 2])
        self.assertEqual(packed.unsorted_indices, [0, 1, 2])

        packed_unsorted = rnn_utils.pack_sequence([b, c, a], enforce_sorted=False)
        self.assertEqual(packed_unsorted.batch_sizes, [3, 2, 1])
        self.assertEqual(packed_unsorted.data.data, expected)
        self.assertEqual(packed_unsorted.sorted_indices, [2, 0, 1])
        self.assertEqual(packed_unsorted.unsorted_indices, [1, 2, 0])

        # single dimensional, enforce_sorted = True
        packed_enforce_sorted = rnn_utils.pack_sequence([a, b, c], enforce_sorted=True)
        self.assertEqual(packed_enforce_sorted.batch_sizes, [3, 2, 1])
        self.assertEqual(packed_enforce_sorted.data.data, expected)
        self.assertTrue(packed_enforce_sorted.sorted_indices is None)
        self.assertTrue(packed_enforce_sorted.unsorted_indices is None)

        with self.assertRaisesRegex(RuntimeError, 'must be sorted in decreasing order'):
            rnn_utils.pack_sequence([b, c, a], enforce_sorted=True)

        with self.assertRaisesRegex(RuntimeError, 'You can pass `enforce_sorted=False`'):
            rnn_utils.pack_sequence([b, c, a], enforce_sorted=True)

        # more dimensions
        maxlen = 9
        for num_dim in (0, 1, 2, 3):
            sequences = []
            lengths = []
            trailing_dims = [4] * num_dim
            for i in range(maxlen, 0, -1):
                seq_len = i * i
                lengths.append(seq_len)
                sequences.append(torch.rand(seq_len, 5, *trailing_dims))
            unsorted_sequences = [s.clone() for s in sequences]
            random.shuffle(unsorted_sequences)
            unsorted_sequences_lengths = [t.size(0) for t in unsorted_sequences]

            # compatibility with other utilities
            for batch_first in (True, False):
                for enforce_sorted in (True, False):
                    _compatibility_test(sequences, lengths, batch_first, enforce_sorted)
                _compatibility_test(unsorted_sequences, unsorted_sequences_lengths,
                                    batch_first)

    def test_pack_padded_sequence(self):
        def generate_test_case(sorted_lengths, should_shuffle):
            def pad(tensor, length):
                return torch.cat([tensor, tensor.new(length - tensor.size(0), *tensor.size()[1:]).zero_()])

            max_length = sorted_lengths[0]
            batch_sizes = [sum(map(bool, filter(lambda x: x >= i, sorted_lengths)))
                           for i in range(1, max_length + 1)]
            offset = 0
            padded = torch.cat([pad(i * 100 + torch.arange(1., 5 * l + 1).view(l, 1, 5), max_length)
                                for i, l in enumerate(sorted_lengths, 1)], 1)
            expected_data = [[torch.arange(1., 6) + (i + 1) * 100 + 5 * n for i in range(batch_size)]
                             for n, batch_size in enumerate(batch_sizes)]
            expected_data = list(itertools.chain.from_iterable(expected_data))
            expected_data = torch.stack(expected_data, dim=0)

            if should_shuffle:
                # Shuffle the padded sequence to create an unsorted sequence
                permutation = list(range(len(sorted_lengths)))
                random.shuffle(permutation)

                unsorted_indices = torch.tensor(permutation)
                padded = padded.index_select(1, unsorted_indices)
                lengths = torch.tensor(sorted_lengths).index_select(0, unsorted_indices)
            else:
                unsorted_indices = None
                lengths = sorted_lengths

            return padded.requires_grad_(), lengths, expected_data, batch_sizes, unsorted_indices

        test_cases = [
            # sorted_lengths, should_shuffle
            [[10, 8, 4, 2, 2, 2, 1], False],
            [[11, 10, 8, 6, 4, 3, 1], False],
            [[11, 10, 8, 6, 4, 3, 1], True],
        ]

        for test_case, batch_first in itertools.product(test_cases, (True, False)):
            sorted_lengths, should_shuffle = test_case
            padded, lengths, expected_data, batch_sizes, unsorted_indices = generate_test_case(
                sorted_lengths, should_shuffle)

            src = padded
            if batch_first:
                src = src.transpose(0, 1)

            # check output
            packed = rnn_utils.pack_padded_sequence(src, lengths, batch_first=batch_first,
                                                    enforce_sorted=not should_shuffle)
            self.assertEqual(packed.data.data, expected_data)
            self.assertEqual(packed.batch_sizes, batch_sizes)
            self.assertEqual(packed.unsorted_indices, unsorted_indices)

            # test inverse
            unpacked, unpacked_len = rnn_utils.pad_packed_sequence(packed, batch_first=batch_first)
            self.assertEqual(unpacked, src)
            self.assertEqual(unpacked_len, lengths)

            # check grad
            if padded.grad is not None:
                padded.grad.data.zero_()
            grad_output = unpacked.data.clone().normal_()
            unpacked.backward(grad_output)
            if batch_first:
                grad_output.transpose_(0, 1)
            for i, l in enumerate(lengths):
                self.assertEqual(padded.grad.data[:l, i], grad_output[:l, i])
                if l < 10:
                    self.assertEqual(padded.grad.data[l:, i].abs().sum(), 0)

        # test error message
        with self.assertRaisesRegex(RuntimeError, 'You can pass `enforce_sorted=False`'):
            packed = rnn_utils.pack_padded_sequence(torch.randn(3, 3), [1, 3, 2])

    def _test_variable_sequence(self, device="cpu", dtype=torch.float):
        def pad(var, length):
            if var.size(0) == length:
                return var
            return torch.cat([var, var.new_zeros(length - var.size(0), *var.size()[1:])])

        def maybe_index_tuple(maybe_tuple_of_tensors, index):
            if maybe_tuple_of_tensors is None:
                return None
            return tuple(maybe_tuple_of_tensors[j][:, index:index + 1, :].contiguous()
                         for j in range(2))

        def check_lengths(lengths, enforce_sorted, use_default_hiddens):
            input_size = 3
            hidden_size = 4
            num_layers = 2
            bidirectional = True

            max_length = max(lengths)
            x_leaf = torch.randn(max_length, len(lengths), input_size, device=device,
                                 dtype=dtype, requires_grad=True)
            num_directions = 2 if bidirectional else 1
            lstm = nn.LSTM(input_size, hidden_size, bidirectional=bidirectional,
                           num_layers=num_layers).to(device, dtype)
            lstm2 = deepcopy(lstm).to(device, dtype)
            x = x_leaf

            hidden0 = None
            if not use_default_hiddens:
                hidden0 = tuple(torch.randn(num_directions * num_layers, len(lengths), hidden_size,
                                            device=device, dtype=dtype)
                                for _ in range(2))

            # Compute sequences separately
            seq_outs = []
            seq_hiddens = []
            for i, l in enumerate(lengths):
                hidden_i = maybe_index_tuple(hidden0, i)
                out, hid = lstm2(x[:l, i:i + 1], hidden_i)
                out_pad = pad(out, max_length)
                seq_outs.append(out_pad)
                seq_hiddens.append(hid)
            seq_out = torch.cat(seq_outs, 1)
            seq_hidden = tuple(torch.cat(hids, 1) for hids in zip(*seq_hiddens))

            # Use packed format
            packed = rnn_utils.pack_padded_sequence(x, lengths, enforce_sorted=enforce_sorted)
            packed_out, packed_hidden = lstm(packed, hidden0)
            unpacked, unpacked_len = rnn_utils.pad_packed_sequence(packed_out)

            # Check forward
            prec = dtype2prec[dtype]
            self.assertEqual(packed_hidden, seq_hidden, prec)
            self.assertEqual(unpacked, seq_out, prec)
            self.assertEqual(unpacked_len, lengths, prec)

            # Check backward
            seq_out.sum().backward()
            grad_x = x_leaf.grad.data.clone()
            x_leaf.grad.data.zero_()
            unpacked.sum().backward()

            self.assertEqual(x_leaf.grad, grad_x, dtype2prec[dtype])
            for p1, p2 in zip(lstm.parameters(), lstm2.parameters()):
                prec = dtype2prec[dtype]
                if dtype == torch.float16:
                    prec = 2e-2
                self.assertEqual(p1.grad, p2.grad, prec)

        tests = [
            # enforce_sorted, lengths
            [True, [5]],
            [False, [5]],
            [True, [10, 10, 6, 2, 2, 1, 1]],
            [False, [10, 10, 6, 2, 2, 1, 1]],
            [False, [2, 1, 3, 2, 10, 5, 3]],
        ]

        for enforce_sorted, seq_lens, in tests:
            for use_default_hiddens in (True, False):
                check_lengths(seq_lens, enforce_sorted, use_default_hiddens)

    def test_variable_sequence(self):
        self._test_variable_sequence()

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_variable_sequence_cuda(self, dtype=torch.float):
        self._test_variable_sequence("cuda", dtype)

    def test_LSTM_cell(self):
        # this is just a smoke test; these modules are implemented through
        # autograd so no Jacobian test is needed
        for bias in (True, False):
            input = torch.randn(3, 10)
            hx = torch.randn(3, 20)
            cx = torch.randn(3, 20)
            lstm = nn.LSTMCell(10, 20, bias=bias)
            for _ in range(6):
                hx, cx = lstm(input, (hx, cx))

            (hx + cx).sum().backward()

    @unittest.skipIf(not (TEST_CUDNN and TEST_MULTIGPU), 'CUDNN or multi-gpu not available')
    def test_cudnn_rnn_dropout_states_device(self):
        rnn = nn.RNN(10, 20, num_layers=2, dropout=.5)
        device = 1
        input = torch.randn(5, 4, 10).cuda(device)
        rnn.cuda(device)
        hx = torch.randn(2, 4, 20).cuda(device)
        output = rnn(input, hx)

    @unittest.skipIf(not TEST_CUDNN, 'CUDNN not available')
    @skipIfRocm
    def test_cudnn_weight_format(self):
        rnns = [
            nn.LSTM(10, 20, batch_first=True),
            nn.GRU(10, 20, batch_first=True),
            nn.RNN(10, 20, batch_first=True)
        ]
        first_warn = True
        for rnn in rnns:
            rnn.cuda()
            input = Variable(torch.randn(5, 4, 10).cuda(), requires_grad=True)
            hx = Variable(torch.randn(1, 5, 20).cuda(), requires_grad=True)
            all_vars = [input, hx] + list(rnn.parameters())
            if isinstance(rnn, nn.LSTM):
                cx = Variable(torch.randn(1, 5, 20).cuda(), requires_grad=True)
                all_vars[2:2] = [cx]
                hx = (hx, cx)

            output = rnn(input, hx)
            output[0].sum().backward()
            grads = [v.grad.data.clone() for v in all_vars]
            for v in all_vars:
                v.grad.data.zero_()

            # Weights will no longer view onto the same chunk of memory
            weight = all_vars[4]
            weight_data = weight.data.clone()
            with torch.no_grad():
                weight.set_(weight_data)

            for _ in range(2):
                with warnings.catch_warnings(record=True) as w:
                    output_noncontig = rnn(input, hx)
                if first_warn:
                    self.assertEqual(len(w), 1)
                    self.assertIn('weights are not part of single contiguous chunk of memory', w[0].message.args[0])
                    first_warn = False
                    warnings.resetwarnings()
                output_noncontig[0].sum().backward()
                grads_noncontig = [v.grad.data.clone() for v in all_vars]
                for v in all_vars:
                    v.grad.data.zero_()
                self.assertEqual(output, output_noncontig)
                self.assertEqual(grads_noncontig, grads)

            # Make sure these still share storage
            weight_data[:] = 4
            self.assertEqual(weight_data, all_vars[4].data)

    @unittest.skipIf(not TEST_CUDNN, 'CUDNN not available')
    def test_cudnn_weight_tying(self):
        rnns = [
            nn.LSTM(10, 20, batch_first=True, bidirectional=True),
            nn.GRU(10, 20, batch_first=True, bidirectional=True),
            nn.RNN(10, 20, batch_first=True, bidirectional=True)
        ]
        for rnn in rnns:
            rnn.bias_ih_l0_reverse = rnn.bias_ih_l0
            rnn.cuda()
            input = Variable(torch.randn(5, 4, 10).cuda(), requires_grad=True)
            hx = Variable(torch.randn(2, 5, 20).cuda(), requires_grad=True)
            all_vars = [input, hx] + list(rnn.parameters())
            opt = torch.optim.SGD(rnn.parameters(), lr=0.1)
            opt.zero_grad()
            if isinstance(rnn, nn.LSTM):
                cx = Variable(torch.randn(2, 5, 20).cuda(), requires_grad=True)
                all_vars[2:2] = [cx]
                hx = (hx, cx)

            with warnings.catch_warnings(record=True) as w:
                output = rnn(input, hx)
            output[0].sum().backward()

            opt.step()
            with warnings.catch_warnings(record=True) as w:
                output_cuda = rnn(input, hx)
            rnn.cpu()
            hx = (hx[0].cpu(), hx[1].cpu()) if isinstance(rnn, nn.LSTM) else hx.cpu()
            output_cpu = rnn(input.cpu(), hx)
            self.assertEqual(output_cuda, output_cpu)

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @repeat_test_for_types(NO_HALF_TENSORTYPES)
    def test_cuda_rnn_fused(self, dtype=torch.float):

        def copy_rnn(rnn1, rnn2):
            for x_layer, y_layer in zip(rnn1.all_weights, rnn2.all_weights):
                for x, y in zip(x_layer, y_layer):
                    x.data.copy_(y.data)

        def check_rnn_grads(rnn1, rnn2):
            for x_layer, y_layer in zip(rnn1.all_weights, rnn2.all_weights):
                for x, y in zip(x_layer, y_layer):
                    self.assertEqual(x.grad, y.grad, prec=5e-5)

        input_size = 10
        hidden_size = 6
        num_layers = 2
        seq_length = 7
        batch = 6
        input_val = torch.randn(seq_length, batch, input_size, dtype=dtype)
        grad_output = torch.randn(seq_length, batch, hidden_size, dtype=dtype)
        hx_val = torch.randn(num_layers, batch, hidden_size, dtype=dtype)
        grad_hy = torch.randn(num_layers, batch, hidden_size, dtype=dtype)
        with torch.backends.cudnn.flags(enabled=False):
            for module in (nn.GRU, nn.LSTM):
                for bias in (True, False):
                    rnn = module(input_size, hidden_size, num_layers, bias=bias).to(dtype)
                    rnn_cuda = module(input_size, hidden_size, num_layers, bias=bias).to("cuda", dtype)
                    copy_rnn(rnn, rnn_cuda)

                    is_lstm = isinstance(rnn, nn.LSTM)
                    if is_lstm:
                        hx = (Variable(hx_val.clone(), requires_grad=True),
                              Variable(hx_val.clone().add(1), requires_grad=True))
                        hx_cuda = (Variable(hx_val.clone().cuda(), requires_grad=True),
                                   Variable(hx_val.clone().cuda().add(1), requires_grad=True))
                    else:
                        hx = Variable(hx_val.clone(), requires_grad=True)
                        hx_cuda = Variable(hx_val.clone().cuda(), requires_grad=True)

                    inp = Variable(input_val.clone(), requires_grad=True)
                    inp_cu = Variable(input_val.clone().cuda(), requires_grad=True)
                    output1, hy1 = rnn(inp, hx)
                    output2, hy2 = rnn_cuda(inp_cu, hx_cuda)
                    if is_lstm:
                        torch.autograd.backward(
                            [output1, hy1[0], hy1[1]], [grad_output, grad_hy, grad_hy + 1]
                        )
                        torch.autograd.backward(
                            [output2, hy2[0], hy2[1]],
                            [grad_output.cuda(), grad_hy.cuda(), (grad_hy + 1).cuda()]
                        )
                    else:
                        torch.autograd.backward([output1, hy1], [grad_output, grad_hy])
                        torch.autograd.backward([output2, hy2], [grad_output.cuda(), grad_hy.cuda()])

                    self.assertEqual(output1, output2)
                    self.assertEqual(hy1, hy2)

                    check_rnn_grads(rnn, rnn_cuda)
                    self.assertEqual(inp.grad.data, inp_cu.grad.data)
                    if is_lstm:
                        self.assertEqual(hx[0].grad.data, hx_cuda[0].grad.data)
                        self.assertEqual(hx[1].grad.data, hx_cuda[1].grad.data)
                    else:
                        self.assertEqual(hx.grad.data, hx_cuda.grad.data)

    def test_rnn_args_check(self):
        input_size = 3
        hidden_size = 5
        num_layers = 2
        batch_size = 4
        seq_len = 6
        num_directions = 1
        bad_size = 7  # prime number so that no size can divide it.

        def test(input_shape, hidden_shape, mode):
            for input, hidden in get_inputs(input_shape, hidden_shape, mode):
                model = getattr(nn, mode)(input_size, hidden_size, num_layers)
                self.assertRaises(RuntimeError, lambda: model(input, hidden))

        correct_input_shape = (seq_len, batch_size, input_size)
        correct_hidden_shape = (num_layers * num_directions, batch_size, hidden_size)

        def update_shape(shape, dim, new_dim_size):
            new_shape = list(shape)
            new_shape[dim] = new_dim_size
            return tuple(new_shape)

        def get_inputs(input_shape, hidden_shape, mode):
            '''returns list( tuple(input, hidden) )
            where input, hidden are inputs to a model'''
            input = torch.randn(input_shape)
            hidden = torch.randn(hidden_shape)
            if mode != 'LSTM':
                return [(input, hidden)]
            if hidden_shape == correct_hidden_shape:
                return [(input, (hidden, hidden))]
            good_hidden = torch.randn(correct_hidden_shape)
            return [
                (input, (hidden, good_hidden)),
                (input, (good_hidden, hidden)),
            ]

        rnn_modes = ['RNN', 'GRU', 'LSTM']
        for mode in rnn_modes:
            # Incorrect input batch size
            input_shape = update_shape(correct_input_shape, 1, bad_size)
            hidden_shape = correct_hidden_shape
            test(input_shape, hidden_shape, mode)

            # Incorrect hidden batch size
            input_shape = correct_input_shape
            hidden_shape = update_shape(correct_hidden_shape, 1, bad_size)
            test(input_shape, hidden_shape, mode)

            # Incorrect input size
            input_shape = update_shape(correct_input_shape, 2, bad_size)
            hidden_shape = correct_hidden_shape
            test(input_shape, hidden_shape, mode)

            # Incorrect hidden size
            input_shape = correct_input_shape
            hidden_shape = update_shape(correct_hidden_shape, 2, bad_size)
            test(input_shape, hidden_shape, mode)

            # Incorrect hidden[0]
            input_shape = correct_input_shape
            hidden_shape = update_shape(correct_hidden_shape, 0, bad_size)
            test(input_shape, hidden_shape, mode)

    @unittest.skipIf(not TEST_MULTIGPU, "multi-GPU not supported")
    def test_rnn_check_device(self):
        input_size = 3
        hidden_size = 5
        num_layers = 2
        batch_size = 4
        seq_len = 6
        num_directions = 1

        correct_input_shape = (seq_len, batch_size, input_size)
        correct_hidden_shape = (num_layers * num_directions, batch_size, hidden_size)
        rnn_modes = ['RNN', 'GRU', 'LSTM']

        for mode in rnn_modes:
            model = getattr(nn, mode)(input_size, hidden_size, num_layers)
            input = torch.randn(correct_input_shape)
            hidden = torch.randn(correct_hidden_shape)

            # input and weights are not at the same device
            with self.assertRaisesRegex(RuntimeError,
                                        "Input and parameter tensors are not at the same device"):
                model(input.to('cuda:0'))

            # input and hiddens are not at the same device
            with self.assertRaisesRegex(RuntimeError,
                                        r"Input and hidden tensors are not at the same device"):
                if mode == 'LSTM':
                    model(input, (hidden.to('cuda:0'), hidden.to('cuda:0')))
                else:
                    model(input, (hidden.to('cuda:0')))

            # hidden tensors are not at the same CUDA device
            if mode == 'LSTM':
                with self.assertRaisesRegex(RuntimeError,
                                            "Input and hidden tensors are not at the same device"):
                    model(input.to('cuda:0'), (hidden.to('cuda:0'), hidden.to('cuda:1')))

    def test_rnn_initial_hidden_state(self):
        rnn_modes = ['RNN', 'GRU', 'LSTM']
        for mode in rnn_modes:
            rnn = getattr(nn, mode)(30, 20, 2)
            input = torch.randn(10, 32, 30)
            hidden = torch.zeros(2, 32, 20)

            if mode == 'LSTM':
                hidden = (hidden, hidden)
            output1, hidden1 = rnn(input, hidden)
            output2, hidden2 = rnn(input)
            self.assertEqual(output1, output2)
            self.assertEqual(hidden1, hidden2)

    def _test_rnn_retain_variables(self, device="cpu", dtype=torch.double):
        rnns = [nn.LSTM(10, 20, num_layers=2).to(device, dtype),
                nn.GRU(10, 20, num_layers=2).to(device, dtype),
                nn.RNN(10, 20, num_layers=2).to(device, dtype)]
        for rnn in rnns:
            input = torch.randn(5, 6, 10, device=device, dtype=dtype, requires_grad=True)
            output = rnn(input)
            output[0].sum().backward(retain_graph=True)
            grads = [input.grad.data.clone()] + [p.grad.data.clone() for p in rnn.parameters()]
            for _ in range(4):
                rnn.zero_grad()
                input.grad.data.zero_()
                output[0].sum().backward(retain_graph=True)
                grads2 = [input.grad.data] + [p.grad.data for p in rnn.parameters()]
                self.assertEqual(grads, grads2)

    def test_rnn_retain_variables(self):
        self._test_rnn_retain_variables()

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_rnn_retain_variables_cuda(self, dtype=torch.float):
        with torch.backends.cudnn.flags(enabled=False):
            self._test_rnn_retain_variables("cuda", dtype)
        self._test_rnn_retain_variables("cuda", dtype)

    def _test_RNN_cpu_vs_cudnn(self, dropout):

        def forward_backward(cuda, rnn, input_val, hx_val, grad_output, grad_hy, weights_val):
            is_lstm = isinstance(rnn, nn.LSTM)

            for x_layer, y_layer in zip(rnn.all_weights, weights_val):
                for x, y in zip(x_layer, y_layer):
                    x.data.copy_(y.data)

            if isinstance(input_val, rnn_utils.PackedSequence):
                input = rnn_utils.PackedSequence(
                    Variable(input_val.data.data, requires_grad=True), input_val.batch_sizes)
                input_var = input.data
            else:
                input = Variable(input_val.clone(), requires_grad=True)
                input_var = input
            if is_lstm:
                hx = (Variable(hx_val.clone(), requires_grad=True),
                      Variable(hx_val.add(1), requires_grad=True))
            else:
                hx = Variable(hx_val.clone(), requires_grad=True)

            if cuda:
                rnn.cuda()
                input_var.data = input_var.data.cuda()
                if is_lstm:
                    hx[0].data = hx[0].data.cuda()
                    hx[1].data = hx[1].data.cuda()
                else:
                    hx.data = hx.data.cuda()
                grad_hy = grad_hy.cuda()
                grad_output = grad_output.cuda()

            output, hy = rnn(input, hx)

            if isinstance(output, rnn_utils.PackedSequence):
                output = output.data

            if is_lstm:
                torch.autograd.backward([output, hy[0], hy[1]], [grad_output, grad_hy, grad_hy + 1])
            else:
                torch.autograd.backward([output, hy], [grad_output, grad_hy])

            return {'output': output.data,
                    'hy': hy[0].data if is_lstm else hy.data,
                    'weights': rnn.all_weights,
                    'grad_input': input_var.grad.data,
                    'grad_hx': hx[0].grad.data if is_lstm else hx.grad.data,
                    'cy': hy[1].data if is_lstm else None,
                    'grad_cx': hx[1].grad.data if is_lstm else None}

        input_size = 10
        hidden_size = 6
        num_layers = 2
        seq_length = 7
        batch = 6

        def make_noncontig(tensor):
            ndim = tensor.dim()
            return torch.stack([tensor.clone().zero_(), tensor], ndim).select(ndim, 1)

        def compare_cpu_gpu(outputs_cpu, outputs_gpu):
            self.assertEqual(list(outputs_cpu.keys()), list(outputs_gpu.keys()))
            for key in outputs_cpu.keys():
                if key != 'weights':
                    self.assertEqual(outputs_cpu[key], outputs_gpu[key], prec=5e-5, message=key)

            # check grad weights separately, as nested dict
            for cpu_layer_weight, gpu_layer_weight in zip(outputs_cpu['weights'], outputs_gpu['weights']):
                for (cpu_weight, gpu_weight) in zip(cpu_layer_weight, gpu_layer_weight):
                    self.assertEqual(cpu_weight.grad.data, gpu_weight.grad.data, prec=5e-5)

        for module in (nn.RNN, nn.LSTM, nn.GRU):
            for bias, bidirectional, batch_first, contig, variable_len, lens_as_tensor \
                    in product((True, False), repeat=6):

                num_directions = 2 if bidirectional else 1
                if batch_first:
                    input_val = torch.randn(batch, seq_length, input_size)
                    grad_output = torch.randn(batch, seq_length, hidden_size * num_directions)
                else:
                    input_val = torch.randn(seq_length, batch, input_size)
                    grad_output = torch.randn(seq_length, batch, hidden_size * num_directions)

                if not contig:
                    grad_output = make_noncontig(grad_output)
                    grad_hy = make_noncontig(grad_hy)
                    input_var = make_noncontig(input_val)
                    hx_val = make_noncontig(hx_val)

                hx_val = torch.randn(num_layers * num_directions, batch, hidden_size)
                grad_hy = torch.randn(num_layers * num_directions, batch, hidden_size)

                if variable_len:
                    lengths = [7, 5, 5, 2, 1, 1]
                    if lens_as_tensor:
                        lengths = torch.tensor(lengths, dtype=torch.long)
                    input_val = rnn_utils.pack_padded_sequence(input_val, lengths, batch_first=batch_first)
                    grad_output = rnn_utils.pack_padded_sequence(grad_output, lengths, batch_first=batch_first).data

                rnn = module(input_size,
                             hidden_size,
                             num_layers,
                             bias=bias,
                             dropout=dropout,
                             bidirectional=bidirectional,
                             batch_first=batch_first)

                outputs_cpu = forward_backward(
                    False, rnn, input_val, hx_val, grad_output, grad_hy, rnn.all_weights)

                rnn_gpu = module(input_size,
                                 hidden_size,
                                 num_layers,
                                 bias=bias,
                                 dropout=dropout,
                                 bidirectional=bidirectional,
                                 batch_first=batch_first)

                outputs_gpu = forward_backward(
                    True, rnn_gpu, input_val, hx_val, grad_output, grad_hy, rnn.all_weights)

                compare_cpu_gpu(outputs_cpu, outputs_gpu)

        for nonlinearity in ('tanh', 'relu'):
            hx_val = torch.randn(num_layers, batch, hidden_size)
            input_val = torch.randn(seq_length, batch, input_size)
            grad_output = torch.randn(
                seq_length, batch, hidden_size * num_directions)
            grad_hy = torch.randn(
                num_layers * num_directions, batch, hidden_size)

            rnn = nn.RNN(input_size, hidden_size, num_layers, bias=bias, nonlinearity=nonlinearity)
            outputs_cpu = forward_backward(False, rnn, input_val, hx_val, grad_output, grad_hy, rnn.all_weights)

            rnn_gpu = nn.RNN(input_size, hidden_size, num_layers, bias=bias, nonlinearity=nonlinearity)
            outputs_gpu = forward_backward(True, rnn_gpu, input_val, hx_val, grad_output, grad_hy, rnn.all_weights)

            compare_cpu_gpu(outputs_cpu, outputs_gpu)

    @unittest.skipIf(not TEST_CUDNN, "needs cudnn")
    @default_tensor_type(torch.FloatTensor)  # FIXME: just until torch.cuda.DoubleTensor.sum() implemented
    def test_RNN_cpu_vs_cudnn_no_dropout(self):
        self._test_RNN_cpu_vs_cudnn(0)

    @unittest.skipIf(not TEST_CUDNN, "needs cudnn")
    def test_RNN_cudnn_weight_norm(self):
        input_size = 10
        hidden_size = 6
        num_layers = 2
        seq_length = 7
        batch = 6
        m = nn.LSTM(input_size, hidden_size, num_layers).cuda()
        input = torch.randn(seq_length, batch, input_size).cuda()
        expected_output = m(input)
        # add weight normalization
        name = 'weight_hh_l0'
        m = torch.nn.utils.weight_norm(m, name=name)
        # otherwise, subsequent warnings will be hidden, and further tests rely on them
        warnings.simplefilter("always")
        self.assertEqual(m(input), expected_output)

        # remove weight norm
        m = torch.nn.utils.remove_weight_norm(m, name=name)
        self.assertEqual(m(input), expected_output)

    @unittest.skipIf(not (TEST_CUDNN and TEST_CUDNN_VERSION >= 5103), "needs cudnn >= 5.1")
    @default_tensor_type(torch.FloatTensor)  # FIXME: just until torch.cuda.DoubleTensor.sum() implemented
    def test_RNN_cpu_vs_cudnn_with_dropout(self):
        # Because of dropout randomness, can only compare dropout=0 and dropout=1
        self._test_RNN_cpu_vs_cudnn(1)

    @unittest.skipIf(not (TEST_CUDNN and TEST_CUDNN_VERSION >= 5103), "needs cudnn >= 5.1")
    def test_RNN_dropout(self):
        # checking the assumption that cuDNN sticks dropout in between
        # RNN layers
        for p in (0, 0.276, 0.731, 1):
            for train in (True, False):
                for cuda in (True, False):
                    rnn = nn.RNN(10, 1000, 2, bias=False, dropout=p, nonlinearity='relu')
                    if cuda:
                        rnn.cuda()

                    if train:
                        rnn.train()
                    else:
                        rnn.eval()
                    rnn.weight_ih_l0.data.fill_(1)
                    rnn.weight_hh_l0.data.fill_(1)
                    rnn.weight_ih_l1.data.fill_(1)
                    rnn.weight_hh_l1.data.fill_(1)
                    input = torch.ones(1, 1, 10)
                    hx = torch.zeros(2, 1, 1000)
                    if cuda:
                        input = input.cuda()
                        hx = hx.cuda()

                    output, hy = rnn(input, hx)
                    self.assertEqual(output.data.min(), output.data.max())
                    output_val = output.data[0][0][0]
                    if p == 0 or not train:
                        self.assertEqual(output_val, 10000)
                    elif p == 1:
                        self.assertEqual(output_val, 0)
                    else:
                        self.assertGreater(output_val, 8000)
                        self.assertLess(output_val, 12000)
                        denorm_mod = (output_val * (1 - p)) % 10
                        self.assertLess(min(denorm_mod, 10 - denorm_mod), 1e-2)

                    self.assertEqual(hy[0].data.min(), hy[0].data.max())
                    self.assertEqual(hy[1].data.min(), hy[1].data.max())
                    self.assertEqual(hy.data[0][0][0], 10)
                    self.assertEqual(hy.data[1][0][0], output_val)

    @unittest.skipIf(not (TEST_CUDNN and TEST_CUDNN_VERSION >= 5103), "needs cudnn >= 5.1")
    def test_RNN_dropout_state(self):
        import sys
        if sys.version_info[0] == 2:
            import cPickle as pickle
        else:
            import pickle
        for p in (0, 0.1234):
            for train in (True, False):
                for cuda in (True, False):
                    rnn = nn.RNN(100, 100, 2, bias=False, dropout=p, nonlinearity='relu')
                    if cuda:
                        rnn.cuda()

                    if train:
                        rnn.train()
                    else:
                        rnn.eval()
                    input = torch.rand(1, 1, 100)
                    hx = torch.rand(2, 1, 100)
                    if cuda:
                        input = input.cuda()
                        hx = hx.cuda()

                    output1, hy1 = rnn(input, hx)
                    output2, hy2 = rnn(input, hx)

                    rnn_pickle = pickle.dumps(rnn)
                    rnn2 = pickle.loads(rnn_pickle)
                    rnn2.flatten_parameters()
                    output3, hy3 = rnn2(input, hx)

                    if p == 0 or not train:
                        self.assertEqual(output1, output2)
                        self.assertEqual(output1, output3)
                        self.assertEqual(hy1, hy2)
                        self.assertEqual(hy1, hy3)
                    else:
                        self.assertNotEqual(output1, output2)
                        self.assertNotEqual(output1, output3)
                        self.assertNotEqual(hy1, hy2)
                        self.assertNotEqual(hy1, hy3)

    @unittest.skipIf(not (TEST_CUDNN and TEST_CUDNN_VERSION >= 5103), "needs cudnn >= 5.1")
    def test_RNN_change_dropout(self):
        for train, cuda in product((True, False), repeat=2):
            rnn = nn.RNN(100, 100, 2, dropout=0, nonlinearity='relu')
            input = torch.rand(3, 2, 100)
            if cuda:
                input.data = input.data.cuda()
                rnn.cuda()

            if train:
                rnn.train()
            else:
                rnn.eval()

            prev_output = None
            for p in (0, 0.5, 0, 0.7, 0.2, 1, 0.2, 0):
                rnn.dropout = p
                output1, hy1 = rnn(input)
                output2, hy2 = rnn(input)

                if p == 0 or p == 1 or not train:
                    self.assertEqual(output1, output2)
                    self.assertEqual(hy1, hy2)
                else:
                    self.assertNotEqual(output1, output2)
                    self.assertNotEqual(hy1, hy2)

                if prev_output is not None:
                    if not train:
                        self.assertEqual(output1.data, prev_output)
                        self.assertEqual(output2.data, prev_output)
                    else:
                        self.assertNotEqual(output1.data, prev_output)
                        self.assertNotEqual(output2.data, prev_output)
                prev_output = output1.data

    def _verify_pixel_shuffle(self, input, output, upscale_factor):
        for c in range(output.size(1)):
            for h in range(output.size(2)):
                for w in range(output.size(3)):
                    height_idx = h // upscale_factor
                    weight_idx = w // upscale_factor
                    channel_idx = (upscale_factor * (h % upscale_factor)) + (w % upscale_factor) + \
                                  (c * upscale_factor ** 2)
                    self.assertEqual(output[:, c, h, w], input[:, channel_idx, height_idx, weight_idx])

    def test_inplace_thnn(self):
        modules = [nn.ReLU, nn.ELU, nn.SELU, nn.CELU, nn.RReLU]
        for mod in modules:
            r = mod(inplace=True)
            input = torch.randn(5, 5, requires_grad=True)
            output = r(input + 0)
            grad_output = torch.randn(5, 5)
            grad_output_clone = grad_output.clone()
            output.backward(grad_output)
            self.assertEqual(grad_output, grad_output_clone)

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    @repeat_test_for_types(ALL_TENSORTYPES)
    def test_noncontig_conv_grad_cuda(self, dtype=torch.float):
        # FIXME: remove after adding non-contiguous grad tests for all modules
        module = nn.Conv2d(3, 5, kernel_size=3, padding=1).to("cuda", dtype)
        input = torch.randn(2, 3, 10, 10, dtype=dtype, device="cuda", requires_grad=True)
        output = module(input)

        grad = torch.randn(2, 2, 5, 10, 10, dtype=dtype, device="cuda")[:, 1]
        assert not grad.is_contiguous()
        output.backward(grad, retain_graph=True)
        self.assertIsNotNone(input.grad)
        result = input.grad.data.clone()
        input.grad.data.zero_()

        output.backward(grad.contiguous())
        self.assertEqual(result, input.grad.data, dtype2prec[dtype])

    def test_pixel_shuffle(self):
        batch_size = random.randint(1, 3)
        upscale_factor = random.randint(2, 5)
        channels = random.randint(1, 4) * upscale_factor ** 2
        height = random.randint(5, 10)
        width = random.randint(5, 10)

        input = torch.rand(batch_size, channels, height, width, requires_grad=True)
        ps = nn.PixelShuffle(upscale_factor)
        output = ps(input)
        self._verify_pixel_shuffle(input.data, output.data, upscale_factor)
        output.backward(output.data)
        self.assertEqual(input.data, input.grad.data)

    def test_elu_inplace_view(self):
        v = torch.tensor([1.0, -1.0, 1.0, -1.0], requires_grad=True)

        def func(root):
            x = root.clone()
            view = x.narrow(0, 1, 2)
            res = F.elu(view, inplace=True)
            self.assertIs(res, view)
            return x

        gradcheck(func, [v])
        gradgradcheck(func, [v])

    def test_relu_inplace_view(self):
        v = torch.tensor([1.0, -1.0, 1.0, -1.0], requires_grad=True)

        def func(root):
            x = root.clone()
            view = x.narrow(0, 1, 2)
            res = F.relu(view, inplace=True)
            self.assertIs(res, view)
            return x

        gradcheck(func, [v])
        gradgradcheck(func, [v])

    @unittest.skipIf(not TEST_CUDA, 'CUDA not available')
    def test_PReLU_backward_requires_grad_false(self):
        m = nn.PReLU().to('cuda')
        x = torch.randn(2, 3, 4, 5, requires_grad=False, device='cuda')
        y = m(x)
        y.mean().backward()
        self.assertEqual(x.grad, None)

    def test_bce_loss_always_nonnegative(self):
        target = torch.ones(5)
        input = torch.ones(5)
        self.assertEqual((nn.BCELoss()(input, target) < 0).sum(), 0)

        target = torch.zeros(5)
        input = torch.zeros(5)
        self.assertEqual((nn.BCELoss()(input, target) < 0).sum(), 0)

    def test_bce_with_logits_raises_if_target_and_input_are_different_size(self):
        target = torch.rand(5)
        input = torch.rand(5, 1)
        with self.assertRaises(ValueError):
            nn.BCEWithLogitsLoss()(input, target)

        target = torch.rand(5, 1)
        input = torch.rand(5)
        with self.assertRaises(ValueError):
            nn.BCEWithLogitsLoss()(input, target)

    def test_bce_with_logits_gives_same_result_as_sigmoid_and_bce_loss(self):
        sigmoid = nn.Sigmoid()

        target = torch.rand(64, 4)
        output = torch.rand(64, 4) - 0.5

        self.assertEqual(nn.BCEWithLogitsLoss()(output, target), nn.BCELoss()(sigmoid(output), target))

        weight = torch.rand(4)
        self.assertEqual(nn.BCEWithLogitsLoss(weight)(output, target), nn.BCELoss(weight)(sigmoid(output), target))

        target = torch.zeros(4, 1, dtype=torch.float)
        output = torch.empty(4, 1, dtype=torch.float).fill_(-100)

        self.assertEqual(nn.BCEWithLogitsLoss()(output, target), nn.BCELoss()(sigmoid(output), target))

        self.assertEqual(nn.BCEWithLogitsLoss(reduction='none')(output, target),
                         nn.BCELoss(reduction='none')(sigmoid(output), target))

        weight = torch.rand(1, dtype=torch.float)
        self.assertEqual(nn.BCEWithLogitsLoss(weight)(output, target), nn.BCELoss(weight)(sigmoid(output), target))

    def test_bce_with_logits_has_correct_grad_at_zero(self):
        output = torch.zeros(3, 1, requires_grad=True)
        target = torch.zeros(3, 1)
        nn.BCEWithLogitsLoss(reduction='sum')(output, target).backward()
        expected_grad = torch.empty(3, 1).fill_(0.5)
        self.assertEqual(output.grad, expected_grad)

    def test_bce_with_logits_broadcasts_weights(self):
        target = torch.rand(16, 4)
        output = torch.rand(16, 4) - 0.5

        weight = torch.rand(4)
        out1 = nn.BCEWithLogitsLoss(weight)(output, target)

        weight = weight.expand(16, 4).contiguous()
        out2 = nn.BCEWithLogitsLoss(weight)(output, target)

        self.assertEqual(out1, out2)

        weight = torch.rand(16, 1)
        out1 = nn.BCEWithLogitsLoss(weight)(output, target)

        weight = weight.expand(16, 4).contiguous()
        out2 = nn.BCEWithLogitsLoss(weight)(output, target)

        self.assertEqual(out1, out2)

    def test_bce_with_logits_ones_in_pos_weights_are_the_same_as_none(self):
        target = torch.rand(64, 4)
        output = torch.rand(64, 4) - 0.5
        pos_weight = torch.ones(64, 4)

        self.assertEqual(nn.BCEWithLogitsLoss()(output, target),
                         nn.BCEWithLogitsLoss(pos_weight=pos_weight)(output, target))

    def test_bce_with_logits_broadcasts_pos_weights(self):
        target = torch.rand(64, 4)
        output = torch.rand(64, 4) - 0.5
        pos_weight = torch.rand(4)
        out1 = nn.BCEWithLogitsLoss(pos_weight=pos_weight)(output, target)

        pos_weight1 = pos_weight.expand(1, 4)
        out2 = nn.BCEWithLogitsLoss(pos_weight=pos_weight1)(output, target)

        pos_weight2 = pos_weight.expand(64, 4)
        out3 = nn.BCEWithLogitsLoss(pos_weight=pos_weight2)(output, target)

        self.assertEqual(out1, out2)
        self.assertEqual(out1, out3)

    def test_bce_with_logits_with_pos_weight_has_correct_grad_at_zero(self):
        output = torch.zeros(3, 1, requires_grad=True)
        target = torch.zeros(3, 1)
        pos_weight = torch.ones(3, 1)
        nn.BCEWithLogitsLoss(pos_weight=pos_weight, reduction='sum')(output, target).backward()
        expected_grad = torch.empty(3, 1).fill_(0.5)
        grad = output.grad
        self.assertEqual(grad, expected_grad)

    def test_bce_with_logits_stability(self):
        output = torch.tensor([0., -120.])
        target = torch.tensor([0., 1.])
        pos_weight = torch.tensor([1., 1.])

        out1 = nn.BCEWithLogitsLoss()(output, target)
        self.assertTrue(torch.isfinite(out1).all().item())

        out2 = nn.BCEWithLogitsLoss(pos_weight=pos_weight)(output, target)
        self.assertTrue(torch.isfinite(out2).all().item())

    def test_bce_loss_broadcasts_weights(self):
        sigmoid = nn.Sigmoid()
        target = torch.rand(16, 4)
        output = torch.rand(16, 4) - 0.5

        weight = torch.rand(4)
        out1 = nn.BCELoss(weight)(sigmoid(output), target)

        weight = weight.expand(16, 4).contiguous()
        out2 = nn.BCELoss(weight)(sigmoid(output), target)

        self.assertEqual(out1, out2)

        weight = torch.rand(16, 1)
        out1 = nn.BCELoss(weight)(sigmoid(output), target)

        weight = weight.expand(16, 4).contiguous()
        out2 = nn.BCELoss(weight)(sigmoid(output), target)

        self.assertEqual(out1, out2)

    def test_elu_inplace_gradgrad(self):
        v = torch.randn(8, requires_grad=True)

        def func(root):
            x = root.clone()
            return F.elu(x, inplace=True)

        gradcheck(func, [v])
        gradgradcheck(func, [v])

    def test_hardtanh_inplace_gradgrad(self):
        v = torch.randn(8, requires_grad=True)

        def func(root):
            x = root.clone()
            return F.hardtanh(x, inplace=True)

        gradcheck(func, [v])
        gradgradcheck(func, [v])

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_batchnorm_cudnn_half(self):
        # THNN
        input = torch.randint(1, 10, (2, 3, 2, 2), dtype=torch.half, device="cuda", requires_grad=True)
        m = nn.BatchNorm2d(3).half().cuda()
        thnn_output = m(input)
        thnn_output.sum().backward()
        thnn_input_grad = input.grad.data.clone()
        self.assertEqual(thnn_output.type(), input.type())
        # cuDNN
        if TEST_CUDNN:
            input.grad = None
            m = m.float()
            cudnn_output = m(input)
            cudnn_output.sum().backward()
            cudnn_input_grad = input.grad.data.clone()
            self.assertEqual(cudnn_output.type(), input.type())
            self.assertEqual(cudnn_output, thnn_output)
            self.assertAlmostEqual(cudnn_input_grad, thnn_input_grad, delta=1e-3)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types([torch.float, torch.half])
    def test_batchnorm_large_batch(self, dtype=torch.float):
        bn = nn.BatchNorm1d(1).to('cuda', dtype)
        data = torch.rand(131072, 1, device="cuda", dtype=dtype)
        out = bn(data).sum().backward()

    def _test_batchnorm_update_stats(self, device="cpu", dtype=torch.float):
        module = nn.BatchNorm1d(3).to(device, dtype)

        data = torch.rand(4, 3, device=device, dtype=dtype)

        # training pass
        old_running_mean = module.running_mean.clone()
        old_running_var = module.running_var.clone()
        old_num_batches_tracked = module.num_batches_tracked.clone()
        module(data)
        self.assertNotEqual(old_running_mean, module.running_mean)
        self.assertNotEqual(old_running_var, module.running_var)
        self.assertEqual(old_num_batches_tracked + 1, module.num_batches_tracked)

        # eval pass
        module.eval()
        old_running_mean = module.running_mean.clone()
        old_running_var = module.running_var.clone()
        old_num_batches_tracked = module.num_batches_tracked.clone()
        module(data)
        self.assertEqual(old_running_mean, module.running_mean)
        self.assertEqual(old_running_var, module.running_var)
        self.assertEqual(old_num_batches_tracked, module.num_batches_tracked)

    def test_batchnorm_update_stats(self):
        self._test_batchnorm_update_stats()

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_batchnorm_update_stats_cuda(self):
        self._test_batchnorm_update_stats("cuda", torch.float)
        if TEST_CUDNN:
            with torch.backends.cudnn.flags(enabled=False):
                self._test_batchnorm_update_stats("cuda", torch.float)

    def test_batchnorm_raises_error_if_running_mean_is_not_same_size_as_input(self):
        input = torch.rand(2, 10)
        running_var = torch.rand(10)
        wrong_sizes = [9, 11]
        for size in wrong_sizes:
            with self.assertRaises(RuntimeError):
                F.batch_norm(input, torch.rand(size), running_var)

    def test_batchnorm_raises_error_if_running_var_is_not_same_size_as_input(self):
        input = torch.rand(2, 10)
        running_mean = torch.rand(10)
        wrong_sizes = [9, 11]
        for size in wrong_sizes:
            with self.assertRaises(RuntimeError):
                F.batch_norm(input, running_mean, torch.rand(size))

    def test_batchnorm_raises_error_if_weight_is_not_same_size_as_input(self):
        input = torch.rand(2, 10)
        running_mean = torch.rand(10)
        running_var = torch.rand(10)
        wrong_sizes = [9, 11]
        for size in wrong_sizes:
            with self.assertRaises(RuntimeError):
                F.batch_norm(input, running_mean, running_var, weight=Parameter(torch.rand(size)))

    def test_batchnorm_raises_error_if_bias_is_not_same_size_as_input(self):
        input = torch.rand(2, 10)
        running_mean = torch.rand(10)
        running_var = torch.rand(10)
        wrong_sizes = [9, 11]
        for size in wrong_sizes:
            with self.assertRaises(RuntimeError):
                F.batch_norm(input, running_mean, running_var, bias=Parameter(torch.rand(size)))

    def _test_batchnorm_grad(self, device="cpu", dtype=torch.double):
        bs, n_feat, size_feat = 4, 5, 6
        input = torch.arange(bs * n_feat * size_feat, device=device,
                             requires_grad=True, dtype=dtype).view(bs, n_feat, size_feat)
        weight = torch.arange(1, n_feat + 1, device=device, requires_grad=True, dtype=dtype)
        bias = torch.arange(n_feat, device=device, requires_grad=True, dtype=dtype)
        running_mean = 1 - torch.arange(n_feat, device=device, dtype=dtype)
        running_var = 2 * torch.arange(n_feat, device=device, dtype=dtype)
        for training in [False, True]:
            _assertGradAndGradgradChecks(self, F.batch_norm, (input, running_mean, running_var, weight, bias,
                                                              training, 0.1, 0.0001))

    def _test_batchnorm_eval(self, device="cpu", dtype=torch.float):
        module = nn.BatchNorm1d(3).to(device, dtype)
        module.eval()

        data = torch.rand(4, 3, device=device, dtype=dtype, requires_grad=True)
        grad = torch.rand(4, 3, device=device, dtype=dtype)

        # 1st pass
        res1 = module(data)
        res1.backward(grad)
        grad1 = data.grad.clone()

        # 2nd pass
        if data.grad is not None:
            data.grad.data.zero_()

        res2 = module(data)
        res2.backward(grad)
        grad2 = data.grad.clone()
        self.assertEqual(res1, res2)
        self.assertEqual(grad1, grad2)

        # track_running_stats=False
        module = nn.BatchNorm1d(3, track_running_stats=False).to(device, dtype)

        data = torch.rand(4, 3, device=device, dtype=dtype, requires_grad=True)
        grad = torch.rand(4, 3, device=device, dtype=dtype)

        # 1st pass
        res1 = module(data)
        res1.backward(grad)
        grad1 = data.grad.clone()

        # set eval
        module.eval()

        # 2nd pass
        if data.grad is not None:
            data.grad.data.zero_()

        res2 = module(data)
        res2.backward(grad)
        grad2 = data.grad.clone()
        self.assertEqual(res1, res2)
        self.assertEqual(grad1, grad2)

    def _test_batchnorm_simple_average(self, test_type=torch.FloatTensor):
        module = nn.BatchNorm1d(3, momentum=None).type(test_type)
        zeros = torch.zeros(3).type(test_type)
        ones = torch.ones(3).type(test_type)
        self.assertEqual(module.running_mean, zeros)
        self.assertEqual(module.running_var, ones)

        data1 = torch.rand(4, 3).type(test_type)
        data2 = torch.rand(4, 3).type(test_type)

        # 1st pass
        res1 = module(data1)
        running_mean1 = module.running_mean.clone()
        running_var1 = module.running_var.clone()
        self.assertNotEqual(running_mean1, zeros)
        self.assertNotEqual(running_var1, ones)

        # reset stats
        module.reset_running_stats()
        self.assertEqual(module.running_mean, zeros)
        self.assertEqual(module.running_var, ones)

        # 2nd pass
        res2 = module(data2)
        running_mean2 = module.running_mean.clone()
        running_var2 = module.running_var.clone()
        self.assertNotEqual(running_mean2, zeros)
        self.assertNotEqual(running_var2, ones)

        # reset stats
        module.reset_running_stats()
        self.assertEqual(module.running_mean, zeros)
        self.assertEqual(module.running_var, ones)

        # 3rd (combined) pass
        res3 = module(data1)
        res4 = module(data2)
        self.assertEqual(res3, res1)
        self.assertEqual(res4, res2)
        self.assertAlmostEqual(module.running_mean, (running_mean1 + running_mean2) / 2)
        self.assertAlmostEqual(module.running_var, (running_var1 + running_var2) / 2)

    def test_pairwise_distance(self):
        input1 = torch.randn(4, 4, requires_grad=True)
        input2 = torch.randn(4, 4, requires_grad=True)
        self.assertTrue(gradcheck(lambda x, y: F.pairwise_distance(x, y), (input1, input2)))

    @skipIfRocm
    def test_pdist(self):
        for device, trans in itertools.product(device_(), [False, True]):
            inp = torch.randn(4, 5, dtype=torch.double, device=device, requires_grad=True)
            if trans:
                inp = inp.transpose(0, 1)
            for p in [0, 1, 2, 0.5, 1.5, 2.5, float('inf')]:
                self.assertTrue(gradcheck(lambda x: F.pdist(x, p), (inp,)))

    def test_pdist_zeros(self):
        """Test that grad is still valid when dist is 0"""
        for device in device_():
            inp = torch.randn(1, 3, dtype=torch.double, device=device, requires_grad=True).repeat([2, 1])
            for p in [0, 1, 2, 0.5, 1.5, 2.5, float('inf')]:
                self.assertTrue(gradcheck(lambda x: F.pdist(x, p), (inp,)))

    def test_pdist_empty_row(self):
        for device in device_():
            inp = torch.randn(1, 3, dtype=torch.double, device=device, requires_grad=True)
            self.assertTrue(gradcheck(F.pdist, (inp,)))

    def test_pdist_empty_col(self):
        for device in device_():
            inp = torch.randn(4, 0, dtype=torch.double, device=device, requires_grad=True)
            self.assertTrue(gradcheck(F.pdist, (inp,)))

    @unittest.expectedFailure
    def test_pdist_cpu_gradgrad_unimplemented(self):
        inp = torch.randn(4, 5, requires_grad=True)
        gradgradcheck(F.pdist, (inp,))

    @skipIfRocm
    @unittest.expectedFailure
    def test_pdist_cuda_gradgrad_unimplemented(self):
        inp = torch.randn(4, 5, device='cuda', requires_grad=True)
        gradgradcheck(F.pdist, (inp,))

    def test_cosine_embedding_loss_no_reduce(self):
        input1 = torch.randn(15, 10, requires_grad=True)
        input2 = torch.randn(15, 10, requires_grad=True)
        target = torch.randn(15).sign()
        self.assertTrue(gradcheck(lambda x, y, z: F.cosine_embedding_loss(
            x, y, z, reduction='none'), (input1, input2, target)))
        self.assertEqual(F.cosine_embedding_loss(input1, input2, target, reduction='none'),
                         loss_reference_fns['CosineEmbeddingLoss'](input1, input2, target, reduction='none'))

    def test_cosine_embedding_loss_margin_no_reduce(self):
        input1 = torch.randn(15, 10, requires_grad=True)
        input2 = torch.randn(15, 10, requires_grad=True)
        target = torch.randn(15).sign()
        self.assertTrue(gradcheck(lambda x, y, z: F.cosine_embedding_loss(
            x, y, z, margin=0.5, reduction='none'), (input1, input2, target)))
        self.assertEqual(F.cosine_embedding_loss(input1, input2, target, margin=0.5, reduction='none'),
                         loss_reference_fns['CosineEmbeddingLoss'](input1, input2, target,
                                                                   margin=0.5, reduction='none'))

    def test_margin_ranking_loss_no_reduce(self):
        input1 = torch.randn(15).mul_(10).requires_grad_()
        input2 = torch.randn(15).mul_(10).requires_grad_()
        target = torch.randn(15).sign()
        self.assertTrue(gradcheck(lambda x, y, z: F.margin_ranking_loss(
            x, y, z, reduction='none'), (input1, input2, target)))
        self.assertEqual(F.margin_ranking_loss(input1, input2, target, reduction='none'),
                         loss_reference_fns['MarginRankingLoss'](input1, input2, target, reduction='none'))

    def test_margin_ranking_loss_margin_no_reduce(self):
        input1 = torch.randn(15).mul_(10).requires_grad_()
        input2 = torch.randn(15).mul_(10).requires_grad_()
        target = torch.randn(15).sign()
        self.assertTrue(gradcheck(lambda x, y, z: F.margin_ranking_loss(
            x, y, z, margin=0.5, reduction='none'), (input1, input2, target)))
        self.assertEqual(F.margin_ranking_loss(input1, input2, target, margin=0.5, reduction='none'),
                         loss_reference_fns['MarginRankingLoss'](input1, input2, target, margin=0.5, reduction='none'))

    def test_triplet_margin_loss(self):
        input1 = torch.randn(5, 10, requires_grad=True)
        input2 = torch.randn(5, 10, requires_grad=True)
        input3 = torch.randn(5, 10, requires_grad=True)
        self.assertTrue(gradcheck(lambda x1, x2, x3: F.triplet_margin_loss(
            x1, x2, x3), (input1, input2, input3)))
        self.assertEqual(F.triplet_margin_loss(input1, input2, input3),
                         loss_reference_fns['TripletMarginLoss'](input1, input2, input3))

    def test_triplet_margin_loss_swap(self):
        input1 = torch.randn(5, 10, requires_grad=True)
        input2 = torch.randn(5, 10, requires_grad=True)
        input3 = torch.randn(5, 10, requires_grad=True)
        self.assertTrue(gradcheck(lambda x1, x2, x3: F.triplet_margin_loss(
            x1, x2, x3, swap=True), (input1, input2, input3)))
        self.assertEqual(F.triplet_margin_loss(input1, input2, input3, swap=True),
                         loss_reference_fns['TripletMarginLoss'](input1, input2, input3, swap=True))

    def test_triplet_margin_loss_no_reduce(self):
        input1 = torch.randn(5, 10, requires_grad=True)
        input2 = torch.randn(5, 10, requires_grad=True)
        input3 = torch.randn(5, 10, requires_grad=True)
        self.assertTrue(gradcheck(lambda x1, x2, x3: F.triplet_margin_loss(
            x1, x2, x3, reduction='none'), (input1, input2, input3)))
        self.assertEqual(F.triplet_margin_loss(input1, input2, input3, reduction='none'),
                         loss_reference_fns['TripletMarginLoss'](input1, input2, input3, reduction='none'))

    def test_triplet_margin_loss_swap_no_reduce(self):
        input1 = torch.randn(5, 10, requires_grad=True)
        input2 = torch.randn(5, 10, requires_grad=True)
        input3 = torch.randn(5, 10, requires_grad=True)
        self.assertTrue(gradcheck(lambda x1, x2, x3: F.triplet_margin_loss(
            x1, x2, x3, swap=True, reduction='none'), (input1, input2, input3)))
        self.assertEqual(F.triplet_margin_loss(input1, input2, input3, swap=True, reduction='none'),
                         loss_reference_fns['TripletMarginLoss'](input1, input2, input3, swap=True, reduction='none'))

    def test_pointwise_loss_target_grad_none_reduction(self):
        i = torch.randn(5, 10)
        t = torch.randn(5, 10, requires_grad=True)
        self.assertEqual(F.mse_loss(i, t, reduction='none').size(), t.size())
        self.assertEqual(F.l1_loss(i, t, reduction='none').size(), t.size())

    def test_pointwise_loss_broadcast(self):
        losses = {
            'mse_loss': lambda x, y, r: F.mse_loss(x, y, reduction=r),
            'l1_loss': lambda x, y, r: F.l1_loss(x, y, reduction=r),
            'smooth_l1_loss': lambda x, y, r: F.smooth_l1_loss(x, y, reduction=r),
        }

        input = torch.randn(2, 1, requires_grad=True)
        for _name, fn in losses.items():
            for requires_grad in [True, False]:
                # When target.requires_grad=True, its impl is in Python, while the other is in TH.
                target = torch.randn(2, 10, requires_grad=requires_grad)
                for reduction in ['none', 'mean', 'sum']:
                    l = fn(input, target, reduction)
                    if reduction == 'none':
                        self.assertEqual(l.size(), target.size())
                    self.assertTrue(gradcheck(fn, (input, target, reduction)))

    def test_cosine_similarity(self):
        input1 = torch.randn(4, 4, requires_grad=True)
        input2 = torch.randn(4, 4, requires_grad=True)
        self.assertTrue(gradcheck(lambda x, y: F.cosine_similarity(x, y), (input1, input2)))

        input1 = torch.randn(4, 5, 6, requires_grad=True)
        input2 = torch.randn(4, 5, 6, requires_grad=True)
        self.assertTrue(gradcheck(lambda x, y: F.cosine_similarity(x, y, dim=0), (input1, input2)))
        self.assertTrue(gradcheck(lambda x, y: F.cosine_similarity(x, y, dim=-1), (input1, input2)))

        input1 = torch.randn((), requires_grad=True)
        input2 = torch.randn((), requires_grad=True)
        self.assertTrue(gradcheck(lambda x, y: F.cosine_similarity(x, y, dim=0), (input1, input2)))
        self.assertTrue(gradcheck(lambda x, y: F.cosine_similarity(x, y, dim=-1), (input1, input2)))

        # Check cosine_similarity input/output shapes
        input_size = (1, 3, 2, 1)
        expected_size = (1, 2, 1)
        input1 = torch.randn(input_size, requires_grad=True)
        input2 = torch.randn(input_size, requires_grad=True)
        self.assertEqual(F.cosine_similarity(input1, input2, dim=1).size(), expected_size)

        # Check numerical precision, issue #18057
        vv1 = torch.tensor(list([float(i) for i in range(84)])).unsqueeze(0)
        vv2 = torch.tensor(list([float(i) for i in range(84)])).unsqueeze(0)
        out = F.cosine_similarity(vv1, vv2)
        self.assertLessEqual(out, 1.0)

        # Check dividing by 0.
        input1 = torch.randn(10).requires_grad_()
        input2 = torch.zeros_like(input1).requires_grad_()
        torch.cosine_similarity(input1, input2, 0).sum().backward()
        self.assertEqual(input1.grad, torch.zeros_like(input1))
        self.assertEqual(input2.grad, input1 * 1e8)

    def test_grid_sample_error_checking(self):
        input = torch.empty(1, 1, 2, 2)
        grid = torch.empty(1, 1, 1, 2)

        # assert no error
        F.grid_sample(input, grid)

        with self.assertRaisesRegex(ValueError, "but got: 'garbage'"):
            F.grid_sample(input, grid, mode='garbage')

        with self.assertRaisesRegex(ValueError, "but got: 'garbage'"):
            F.grid_sample(input, grid, padding_mode='garbage')

        with self.assertRaisesRegex(RuntimeError, "expected input and grid to have same dtype"):
            F.grid_sample(input.float(), grid.double())

        with self.assertRaisesRegex(RuntimeError, "expected 4D or 5D input"):
            F.grid_sample(input[0], grid)

        with self.assertRaisesRegex(RuntimeError, "grid with same number of dimensions"):
            F.grid_sample(input, torch.empty(1, 1, 1, 1, 3))

        with self.assertRaisesRegex(RuntimeError, "expected grid and input to have same batch size"):
            F.grid_sample(input, torch.empty(2, 1, 1, 2))

        with self.assertRaisesRegex(RuntimeError, "expected grid to have size 2 in last dimension"):
            F.grid_sample(input, torch.empty(1, 1, 1, 3))

        with self.assertRaisesRegex(RuntimeError, "expected input to have non-empty spatial dimensions"):
            F.grid_sample(torch.empty(1, 1, 0, 2), grid)

        if TEST_CUDA:
            with self.assertRaisesRegex(RuntimeError, "expected input and grid to be on same device"):
                F.grid_sample(input.cuda(), grid)

    def test_grid_sample(self):
        def test(N, C, H, W, mode, padding_mode):
            def test_shape(N, C, IH, IW, H, W, mode, padding_mode):
                for grid_dim_contig_order in [(0, 1, 2, 3), (0, 3, 1, 2), (3, 0, 1, 2), (0, 2, 1, 3)]:
                    # grid_dim_contig_order specifies the dimension order that can
                    # make grid to be contiguous.
                    # i.e., grid.permute(grid_dim_contig_order) is contiguous.
                    # e.g., with grid_dim_contig_order=[0, 3, 1, 2], grid should be
                    #       initialized with contiguous tensor of shape [N, 2, H, W]
                    #       and permuted to [N, H, W, 2] afterwards.
                    grid_shape = [N, H, W, 2]
                    grid_init_shape = [grid_shape[d] for d in grid_dim_contig_order]
                    grid_fwd_permute = [None, None, None, None]
                    for i, d in enumerate(grid_dim_contig_order):
                        grid_fwd_permute[d] = i

                    def get_grid(device='cpu', data=None):
                        if data is not None:
                            assert list(data.shape) == grid_shape
                            data = data.permute(grid_dim_contig_order).to(device)
                        else:
                            data = torch.randn(grid_init_shape, device=device)
                        grid = data.permute(grid_fwd_permute)
                        assert grid.permute(grid_dim_contig_order).is_contiguous()
                        return grid

                    input_cpu = torch.randn(C, N, IH, IW).transpose(0, 1).requires_grad_()
                    grid_cpu = get_grid().requires_grad_()
                    out_cpu = F.grid_sample(input_cpu, grid_cpu, mode=mode, padding_mode=padding_mode)
                    self.assertTrue(out_cpu.size() == torch.Size([N, C, H, W]))

                    gradients = torch.randn_like(out_cpu)
                    out_cpu.backward(gradients)

                    if TEST_CUDA:
                        input_cuda = input_cpu.detach().transpose(0, 1).cuda().transpose(0, 1).requires_grad_()
                        grid_cuda = get_grid('cuda', grid_cpu.detach()).requires_grad_()
                        out_cuda = F.grid_sample(input_cuda, grid_cuda, mode=mode, padding_mode=padding_mode)
                        self.assertEqual(out_cpu, out_cuda)

                        out_cuda.backward(gradients.cuda())
                        self.assertEqual(input_cpu.grad, input_cuda.grad)
                        self.assertEqual(grid_cpu.grad, grid_cuda.grad, prec=5e-5)

                        # check that zero-dimensional input strides don't error out
                        base_input = torch.randn(N, C, 1, IW)
                        input_cpu = base_input.expand_as(input_cuda).requires_grad_()
                        out_cpu = F.grid_sample(input_cpu, grid_cpu, mode=mode, padding_mode=padding_mode)

                        input_cuda = base_input.cuda().expand_as(input_cuda).requires_grad_()
                        out_cuda = F.grid_sample(input_cuda, grid_cuda, mode=mode, padding_mode=padding_mode)
                        self.assertEqual(out_cpu, out_cuda)

            # test same size output
            test_shape(N, C, H, W, H, W, mode, padding_mode)

            # test larger output
            N = random.randint(2, 8)
            C = random.randint(2, 8)
            IH = random.randint(2, 8)
            IW = random.randint(2, 8)
            H = random.randint(IH + 1, 12)
            W = random.randint(IW + 1, 12)
            test_shape(N, C, IH, IW, H, W, mode, padding_mode)

            # test smaller output
            N = random.randint(2, 8)
            C = random.randint(2, 8)
            IH = random.randint(2, 8)
            IW = random.randint(2, 8)
            H = random.randint(2, IH)
            W = random.randint(2, IW)
            test_shape(N, C, IH, IW, H, W, mode, padding_mode)

            # test 1x1 inpput
            N = random.randint(2, 8)
            C = random.randint(2, 8)
            IH = 1
            IW = 1
            H = random.randint(2, 5)
            W = random.randint(2, 5)
            test_shape(N, C, IH, IW, H, W, mode, padding_mode)

            # testing empty grid
            N = random.randint(2, 8)
            C = random.randint(2, 8)
            IH = random.randint(2, 8)
            IW = random.randint(2, 8)
            W = random.randint(3, IW + 2)
            test_shape(N, C, IH, IW, 0, W, mode, padding_mode)

            # testing empty channel
            N = random.randint(2, 8)
            IH = random.randint(2, 8)
            IW = random.randint(2, 8)
            H = random.randint(3, IH + 2)
            W = random.randint(3, IW + 2)
            test_shape(N, 0, IH, IW, H, W, mode, padding_mode)

            # testing empty batch
            C = random.randint(2, 8)
            IH = random.randint(2, 8)
            IW = random.randint(2, 8)
            H = random.randint(3, IH + 2)
            W = random.randint(3, IW + 2)
            test_shape(0, C, IH, IW, H, W, mode, padding_mode)

        for mode in ('bilinear', 'nearest'):
            for padding_mode in ('zeros', 'border', 'reflection'):
                # test known input on CPU
                input = torch.arange(1., 11).view(1, 1, 2, 5)
                grid = torch.tensor(
                    [[[-0.9, -4.1], [0, 0.2000], [1, -1], [-0.333, 1e-10], [0.5, 1.0]],
                     [[-1.0, -0.5], [0, 0.3333], [1, -1], [-0.200, 1e-10], [1.5, 0.5]]]).view(1, 2, 5, 2)
                if mode == 'bilinear':
                    if padding_mode == 'zeros':
                        groundtruth = torch.tensor(
                            [[0.0000, 6.0000000000, 5.0000, 4.8340, 9.0000],
                             [2.2500, 6.3332500450, 5.0000, 5.1000, 0.0000]]).view(1, 1, 2, 5)
                    elif padding_mode == 'border':
                        groundtruth = torch.tensor(
                            [[1.2000, 6.0000000000, 5.0000, 4.8340, 9.0000],
                             [2.2500, 6.3332500450, 5.0000, 5.1000, 8.7500]]).view(1, 1, 2, 5)
                    elif padding_mode == 'reflection':
                        groundtruth = torch.tensor(
                            [[3.4500, 6.0000000000, 5.0000, 4.8340, 9.0000],
                             [2.2500, 6.3332500450, 5.0000, 5.1000, 7.7500]]).view(1, 1, 2, 5)
                    else:
                        assert False, "missing groundtruth test for padding mode '{}'".format(padding_mode)
                elif mode == 'nearest':
                    if padding_mode == 'zeros':
                        groundtruth = torch.tensor(
                            [[0., 8., 5., 7., 9.],
                             [1., 8., 5., 8., 0.]]).view(1, 1, 2, 5)
                    elif padding_mode == 'border':
                        groundtruth = torch.tensor(
                            [[1., 8., 5., 7., 9.],
                             [1., 8., 5., 8., 10.]]).view(1, 1, 2, 5)
                    elif padding_mode == 'reflection':
                        groundtruth = torch.tensor(
                            [[1., 8., 5., 7., 9.],
                             [1., 8., 5., 8., 9.]]).view(1, 1, 2, 5)
                    else:
                        assert False, "missing groundtruth test for padding mode '{}'".format(padding_mode)
                else:
                    assert False, "missing groundtruth test for interpolation mode '{}'".format(mode)
                output = F.grid_sample(input, grid, mode=mode, padding_mode=padding_mode)
                self.assertEqual(output, groundtruth,
                                 "groundtruth comparison failed for mode={}, "
                                 "padding_mode={}".format(mode, padding_mode))

                # do gradcheck
                N = random.randint(2, 8)
                C = random.randint(2, 6)
                H = random.randint(2, 8)
                W = random.randint(2, 8)
                input = torch.randn(N, C, H, W, requires_grad=True)
                grid = torch.randn(N, H, W, 2, requires_grad=True)
                self.assertTrue(gradcheck(
                    lambda inp, grid: F.grid_sample(inp, grid, mode=mode, padding_mode=padding_mode),
                    (input, grid)))

                test(N, C, H, W, mode, padding_mode)
                if TEST_CUDNN:
                    with cudnn.flags(enabled=False):
                        test(N, C, H, W, mode, padding_mode)

    def test_grid_sample_3d(self):
        def test(N, C, D, H, W, mode, padding_mode):
            def test_shape(N, C, ID, IH, IW, D, H, W, mode, padding_mode):
                input_cpu = torch.randn(C, N, ID, IH, IW).transpose(0, 1).requires_grad_()
                grid_cpu = torch.randn(D, N, H, W, 3).transpose(0, 1).requires_grad_()
                out_cpu = F.grid_sample(input_cpu, grid_cpu, mode=mode, padding_mode=padding_mode)
                self.assertTrue(out_cpu.size() == torch.Size([N, C, D, H, W]))

                gradients = torch.randn_like(out_cpu)
                out_cpu.backward(gradients)

                if TEST_CUDA:
                    input_cuda = input_cpu.detach().transpose(0, 1).cuda().transpose(0, 1).requires_grad_()
                    grid_cuda = grid_cpu.detach().transpose(0, 1).cuda().transpose(0, 1).requires_grad_()
                    out_cuda = F.grid_sample(input_cuda, grid_cuda, mode=mode, padding_mode=padding_mode)
                    self.assertEqual(out_cpu, out_cuda)

                    out_cuda.backward(gradients.cuda())
                    self.assertEqual(input_cpu.grad, input_cuda.grad)
                    self.assertEqual(grid_cpu.grad, grid_cuda.grad, prec=5e-5)

                    # check that zero-dimensional input strides don't error out
                    base_input = torch.randn(N, C, 1, IH, IW)
                    input_cpu = base_input.expand_as(input_cuda).requires_grad_()
                    grid_cpu = torch.randn(N, D, H, W, 3, requires_grad=True)
                    out_cpu = F.grid_sample(input_cpu, grid_cpu, mode=mode, padding_mode=padding_mode)

                    input_cuda = base_input.cuda().expand_as(input_cuda).requires_grad_()
                    grid_cuda = grid_cpu.detach().cuda().requires_grad_()
                    out_cuda = F.grid_sample(input_cuda, grid_cuda, mode=mode, padding_mode=padding_mode)
                    self.assertEqual(out_cpu, out_cuda)

            # test same size output
            test_shape(N, C, D, H, W, D, H, W, mode, padding_mode)

            # test larger output
            N = random.randint(2, 7)
            C = random.randint(2, 5)
            ID = random.randint(2, 7)
            IH = random.randint(2, 7)
            IW = random.randint(2, 7)
            D = random.randint(ID + 1, 10)
            H = random.randint(IH + 1, 10)
            W = random.randint(IW + 1, 10)
            test_shape(N, C, ID, IH, IW, D, H, W, mode, padding_mode)

            # test smaller output
            N = random.randint(2, 7)
            C = random.randint(2, 5)
            ID = random.randint(2, 7)
            IH = random.randint(2, 7)
            IW = random.randint(2, 7)
            D = random.randint(2, ID)
            H = random.randint(2, IH)
            W = random.randint(2, IW)
            test_shape(N, C, ID, IH, IW, D, H, W, mode, padding_mode)

            # test 1x1 inpput
            N = random.randint(2, 7)
            C = random.randint(2, 7)
            ID = 1
            IH = 1
            IW = 1
            H = random.randint(2, 5)
            W = random.randint(2, 5)
            test_shape(N, C, ID, IH, IW, D, H, W, mode, padding_mode)

            # testing empty grid
            N = random.randint(2, 7)
            C = random.randint(2, 5)
            ID = random.randint(2, 7)
            IH = random.randint(2, 7)
            IW = random.randint(2, 7)
            D = random.randint(3, ID + 2)
            W = random.randint(3, IW + 2)
            test_shape(N, C, ID, IH, IW, D, 0, W, mode, padding_mode)

            # testing empty channel
            N = random.randint(2, 7)
            ID = random.randint(2, 5)
            IH = random.randint(2, 7)
            IW = random.randint(2, 7)
            D = random.randint(3, ID + 2)
            H = random.randint(3, IH + 2)
            W = random.randint(3, IW + 2)
            test_shape(N, 0, ID, IH, IW, D, H, W, mode, padding_mode)

            # testing empty batch
            C = random.randint(2, 5)
            ID = random.randint(2, 7)
            IH = random.randint(2, 7)
            IW = random.randint(2, 7)
            D = random.randint(3, ID + 2)
            H = random.randint(3, IH + 2)
            W = random.randint(3, IW + 2)
            test_shape(0, C, ID, IH, IW, D, H, W, mode, padding_mode)

        for mode in ('bilinear', 'nearest'):
            for padding_mode in ('zeros', 'border', 'reflection'):
                # do gradcheck
                N = random.randint(2, 5)
                C = random.randint(2, 4)
                D = random.randint(2, 5)
                H = random.randint(2, 5)
                W = random.randint(2, 5)
                input = torch.randn(N, C, D, H, W, requires_grad=True)
                grid = torch.randn(N, D, H, W, 3, requires_grad=True)
                self.assertTrue(gradcheck(
                    lambda inp, grid: F.grid_sample(inp, grid, mode=mode, padding_mode=padding_mode),
                    (input, grid)))

                test(N, C, D, H, W, mode, padding_mode)

    def test_affine_grid(self):
        # test known input on CPU
        input = torch.arange(1., 7).view(1, 2, 3)
        output = F.affine_grid(input, torch.Size([1, 1, 2, 2]))
        groundtruth = torch.Tensor(
            [[[0, -3], [2, 5]], [[4, 7], [6, 15]]]).view(1, 2, 2, 2)
        self.assertEqual(output, groundtruth)

        # do gradcheck
        N = random.randint(1, 8)
        C = random.randint(1, 8)
        H = random.randint(1, 8)
        W = random.randint(1, 8)
        sz = torch.Size([N, C, H, W])
        inp = torch.randn(N, 2, 3, requires_grad=True)
        self.assertTrue(gradcheck(lambda inp: F.affine_grid(inp, sz), (inp,)))

        # test CPU against CUDA
        if TEST_CUDNN:
            input_cpu = torch.randn(N, 2, 3, requires_grad=True)
            out_cpu = F.affine_grid(input_cpu, sz)
            gradients = torch.randn(out_cpu.size())
            out_cpu.backward(gradients)
            input_gpu = input_cpu.detach().cuda().requires_grad_()
            out_cuda = F.affine_grid(input_gpu, sz)
            out_cuda.backward(gradients.cuda())
            self.assertEqual(out_cpu, out_cuda)
            self.assertEqual(input_cpu.grad, input_gpu.grad)

    @unittest.skipIf((not TEST_NUMPY) or (not TEST_SCIPY) or (scipy.__version__ < '1.0.0'),
                     "Scipy v1.0 and/or numpy not found")
    def test_affine_2d_rotate0(self):
        # scipy before 1.0.0 do not support homogeneous coordinate
        # scipy.ndimage.affine_transform, so we need to skip.
        for device in device_():
            input_size = [1, 1, 3, 3]
            input_ary = np.array(np.random.random(input_size), dtype=np.float32)
            output_size = [1, 1, 5, 5]
            angle_rad = 0.

            transform_tensor, transform_ary, offset = \
                _buildEquivalentAffineTransforms2d(device, input_size, output_size, angle_rad)

            scipy_ary = scipy.ndimage.affine_transform(
                input_ary[0, 0],
                transform_ary,
                offset=offset,
                output_shape=output_size[2:],
                order=1,
                mode='nearest',
                prefilter=False)

            affine_tensor = torch.nn.functional.affine_grid(
                transform_tensor,
                torch.Size(output_size)
            )

            gridsample_ary = torch.nn.functional.grid_sample(
                torch.tensor(input_ary, device=device).to(device),
                affine_tensor,
                padding_mode='border'
            ).to('cpu').numpy()

            assert np.abs(scipy_ary.mean() - gridsample_ary.mean()) < 1e-6
            assert np.abs(scipy_ary - gridsample_ary).max() < 1e-6

    @unittest.skipIf((not TEST_NUMPY) or (not TEST_SCIPY) or (scipy.__version__ < '1.0.0'),
                     "Scipy v1.0 and/or numpy not found")
    def test_affine_2d_rotate90(self):
        # scipy before 1.0.0 do not support homogeneous coordinate
        # scipy.ndimage.affine_transform, so we need to skip.
        for device, input_size2dsq, output_size2dsq in \
                itertools.product(device_(), input_size2dsq_(), output_size2dsq_()):
            input_size = input_size2dsq
            input_ary = np.array(np.random.random(input_size), dtype=np.float32)
            output_size = output_size2dsq
            angle_rad = 0.25 * math.pi * 2

            transform_tensor, transform_ary, offset = \
                _buildEquivalentAffineTransforms2d(device, input_size, output_size, angle_rad)

            scipy_ary = scipy.ndimage.affine_transform(
                input_ary[0, 0],
                transform_ary,
                offset=offset,
                output_shape=output_size[2:],
                order=1,
                mode='nearest',
                prefilter=True)

            if input_size2dsq == output_size2dsq:
                assert np.abs(scipy_ary.mean() - input_ary.mean()) < 1e-6
            assert np.abs(scipy_ary[0, 0] - input_ary[0, 0, 0, -1]).max() < 1e-6
            assert np.abs(scipy_ary[0, -1] - input_ary[0, 0, -1, -1]).max() < 1e-6
            assert np.abs(scipy_ary[-1, -1] - input_ary[0, 0, -1, 0]).max() < 1e-6
            assert np.abs(scipy_ary[-1, 0] - input_ary[0, 0, 0, 0]).max() < 1e-6

            affine_tensor = torch.nn.functional.affine_grid(
                transform_tensor,
                torch.Size(output_size)
            )

            gridsample_ary = torch.nn.functional.grid_sample(
                torch.tensor(input_ary, device=device).to(device),
                affine_tensor,
                padding_mode='border'
            ).to('cpu').numpy()

            assert np.abs(scipy_ary.mean() - gridsample_ary.mean()) < 1e-6
            assert np.abs(scipy_ary - gridsample_ary).max() < 1e-6

    @unittest.skipIf((not TEST_NUMPY) or (not TEST_SCIPY) or (scipy.__version__ < '1.0.0'),
                     "Scipy v1.0 and/or numpy not found")
    def test_affine_2d_rotate45(self):
        # scipy before 1.0.0 do not support homogeneous coordinate
        # scipy.ndimage.affine_transform, so we need to skip.
        for device in device_():
            input_size = [1, 1, 3, 3]
            input_ary = np.array(np.zeros(input_size), dtype=np.float32)
            input_ary[0, 0, 0, :] = 0.5
            input_ary[0, 0, 2, 2] = 1.0
            output_size = [1, 1, 3, 3]
            angle_rad = 0.125 * math.pi * 2

            transform_tensor, transform_ary, offset = \
                _buildEquivalentAffineTransforms2d(device, input_size, output_size, angle_rad)

            scipy_ary = scipy.ndimage.affine_transform(
                input_ary[0, 0],
                transform_ary,
                offset=offset,
                output_shape=output_size[2:],
                order=1,
                mode='nearest',
                prefilter=False)

            affine_tensor = torch.nn.functional.affine_grid(
                transform_tensor,
                torch.Size(output_size)
            )

            gridsample_ary = torch.nn.functional.grid_sample(
                torch.tensor(input_ary, device=device).to(device),
                affine_tensor,
                padding_mode='border'
            ).to('cpu').numpy()

            assert np.abs(scipy_ary - gridsample_ary).max() < 1e-6

    @unittest.skipIf((not TEST_NUMPY) or (not TEST_SCIPY) or (scipy.__version__ < '1.0.0'),
                     "Scipy v1.0 and/or numpy not found")
    def test_affine_2d_rotateRandom(self):
        # scipy before 1.0.0 do not support homogeneous coordinate
        # scipy.ndimage.affine_transform, so we need to skip.
        for device, angle_rad, input_size2d, output_size2d in \
                itertools.product(device_(), angle_rad_(), input_size2d_(), output_size2d_()):

            input_size = input_size2d
            input_ary = np.array(np.random.random(input_size), dtype=np.float32).round(3)
            output_size = output_size2d

            input_ary[0, 0, 0, 0] = 2
            input_ary[0, 0, 0, -1] = 4
            input_ary[0, 0, -1, 0] = 6
            input_ary[0, 0, -1, -1] = 8

            transform_tensor, transform_ary, grid_ary = \
                _buildEquivalentAffineTransforms2d(device, input_size, output_size, angle_rad)

            scipy_ary = scipy.ndimage.affine_transform(
                input_ary[0, 0],
                transform_ary,
                output_shape=output_size[2:],
                order=1,
                mode='nearest',
                prefilter=False)

            affine_tensor = torch.nn.functional.affine_grid(
                transform_tensor,
                torch.Size(output_size)
            )

            gridsample_ary = torch.nn.functional.grid_sample(
                torch.tensor(input_ary, device=device).to(device),
                affine_tensor,
                padding_mode='border'
            ).to('cpu').numpy()

            affine_tensor = affine_tensor.to('cpu')

            for r in range(affine_tensor.size(1)):
                for c in range(affine_tensor.size(2)):
                    grid_out = np.dot(grid_ary, [r, c, 1])
                    assert np.allclose(affine_tensor[0, r, c], grid_out[:2], atol=1e-5)

            assert np.abs(scipy_ary - gridsample_ary).max() < 1e-5

    @unittest.skipIf((not TEST_NUMPY) or (not TEST_SCIPY) or (scipy.__version__ < '1.0.0'),
                     "Scipy v1.0 and/or numpy not found")
    def test_affine_3d_rotateRandom(self):
        # scipy before 1.0.0 do not support homogeneous coordinate
        # scipy.ndimage.affine_transform, so we need to skip.
        for device, angle_rad, axis_vector, input_size3d, output_size3d in \
                itertools.product(device_(), angle_rad_(), axis_vector_(), input_size3d_(), output_size3d_()):
            input_size = input_size3d
            input_ary = np.array(np.random.random(input_size), dtype=np.float32)
            output_size = output_size3d

            input_ary[0, 0, 0, 0, 0] = 2
            input_ary[0, 0, 0, 0, -1] = 3
            input_ary[0, 0, 0, -1, 0] = 4
            input_ary[0, 0, 0, -1, -1] = 5
            input_ary[0, 0, -1, 0, 0] = 6
            input_ary[0, 0, -1, 0, -1] = 7
            input_ary[0, 0, -1, -1, 0] = 8
            input_ary[0, 0, -1, -1, -1] = 9

            transform_tensor, transform_ary, grid_ary = \
                _buildEquivalentAffineTransforms3d(device, input_size, output_size, angle_rad, axis_vector)

            scipy_ary = scipy.ndimage.affine_transform(
                input_ary[0, 0],
                transform_ary,
                output_shape=output_size[2:],
                order=1,
                mode='nearest',
                prefilter=False)

            affine_tensor = torch.nn.functional.affine_grid(
                transform_tensor,
                torch.Size(output_size)
            )

            gridsample_ary = torch.nn.functional.grid_sample(
                torch.tensor(input_ary, device=device).to(device),
                affine_tensor,
                padding_mode='border'
            ).to('cpu').numpy()

            affine_tensor = affine_tensor.to('cpu')

            for i in range(affine_tensor.size(1)):
                for r in range(affine_tensor.size(2)):
                    for c in range(affine_tensor.size(3)):
                        grid_out = np.dot(grid_ary, [i, r, c, 1])
                        assert np.allclose(affine_tensor[0, i, r, c], grid_out[:3], atol=1e-5)

            assert np.abs(scipy_ary - gridsample_ary).max() < 1e-5

    def test_upsamplingNearest1d(self):
        m = nn.Upsample(size=4, mode='nearest')
        in_t = torch.ones(1, 1, 2)
        with warnings.catch_warnings(record=True) as w:
            out_t = m(in_t)
        self.assertEqual(torch.ones(1, 1, 4), out_t.data)

        input = torch.randn(1, 1, 2, requires_grad=True)
        gradcheck(lambda x: F.interpolate(x, 4, mode='nearest'), [input])

    def test_upsamplingLinear1d(self):
        for align_corners in [True, False]:
            kwargs = dict(mode='linear', align_corners=align_corners)

            # test float scale factor up & downsampling
            for scale_factor in [0.5, 1.5, 2]:
                m = nn.Upsample(scale_factor=scale_factor, **kwargs)
                in_t = torch.ones(1, 1, 2)
                out_size = int(math.floor(in_t.shape[-1] * scale_factor))
                with warnings.catch_warnings(record=True) as w:
                    out_t = m(in_t)
                self.assertEqual(torch.ones(1, 1, out_size), out_t.data)

                input = torch.randn(1, 1, 2, requires_grad=True)
                gradcheck(lambda x: F.interpolate(x, out_size, **kwargs), (input,))

    def test_upsamplingLinear1d_spatial_invariance(self):
        m = nn.Upsample(scale_factor=3, mode='linear', align_corners=False)
        in_t_9 = torch.zeros(1, 1, 9)
        in_t_9[:, :, :4].normal_()
        with warnings.catch_warnings(record=True) as w:
            out_t_9 = m(in_t_9)
            out_t_5 = m(in_t_9[:, :, :5])
        self.assertEqual(out_t_9[:, :, :15], out_t_5)

    def test_upsamplingNearest2d(self):
        m = nn.Upsample(size=4, mode='nearest')
        in_t = torch.ones(1, 1, 2, 2)
        with warnings.catch_warnings(record=True) as w:
            out_t = m(Variable(in_t))
        self.assertEqual(torch.ones(1, 1, 4, 4), out_t.data)

        input = torch.randn(1, 1, 2, 2, requires_grad=True)
        self.assertEqual(
            F.interpolate(input, 4, mode='nearest'),
            F.interpolate(input, scale_factor=2, mode='nearest'))
        gradcheck(lambda x: F.interpolate(x, 4, mode='nearest'), [input])
        gradgradcheck(lambda x: F.interpolate(x, 4, mode='nearest'), [input])

    def test_upsamplingBilinear2d(self):
        for align_corners in [True, False]:
            kwargs = dict(mode='bilinear', align_corners=align_corners)

            # test float scale factor up & downsampling
            for scale_factor in [0.5, 1.5, 2]:
                m = nn.Upsample(scale_factor=scale_factor, **kwargs)
                in_t = torch.ones(1, 1, 2, 2)
                out_size = int(math.floor(in_t.shape[-1] * scale_factor))
                with warnings.catch_warnings(record=True) as w:
                    out_t = m(in_t)
                self.assertEqual(torch.ones(1, 1, out_size, out_size), out_t.data)

                input = torch.randn(1, 1, 2, 2, requires_grad=True)
                gradcheck(lambda x: F.interpolate(x, out_size, **kwargs), [input])

    def test_upsamplingBicubic2d(self):
        # test output against known input: align_corners=False result must match opencv
        in_t = torch.arange(8).view(1, 2, 2, 2).type(torch.FloatTensor)
        expected_out_t = torch.Tensor(
            [[[[-0.31641, 0.01562, 0.56250, 0.89453],
              [0.34766, 0.67969, 1.22656, 1.55859],
              [1.44141, 1.77344, 2.32031, 2.65234],
              [2.10547, 2.43750, 2.98438, 3.31641]],

             [[3.68359, 4.01562, 4.56250, 4.89453],
              [4.34766, 4.67969, 5.22656, 5.55859],
              [5.44141, 5.77344, 6.32031, 6.65234],
              [6.10547, 6.43750, 6.98438, 7.31641]]]])
        out_t = F.interpolate(in_t, scale_factor=2, mode='bicubic', align_corners=False)
        torch.set_printoptions(precision=5)
        self.assertEqual(out_t, expected_out_t)

        device_list = ['cpu']
        if TEST_CUDA:
            device_list.append('cuda')

        for align_corners in [True, False]:
            kwargs = dict(mode='bicubic', align_corners=align_corners)
            # test float scale factor up & downsampling
            for device in device_list:
                for scale_factor in [0.5, 1.5, 2]:
                    in_t = torch.ones(2, 2, 2, 2).to(device)
                    out_t = F.interpolate(in_t, scale_factor=scale_factor, **kwargs)
                    out_size = int(math.floor(in_t.shape[-1] * scale_factor))
                    self.assertEqual(torch.ones(2, 2, out_size, out_size), out_t.data)

                    input = torch.randn(2, 2, 2, 2, requires_grad=True)
                    gradcheck(lambda x: F.interpolate(x, out_size, **kwargs), [input])

    def test_upsamplingBilinear2d_spatial_invariance(self):
        m = nn.Upsample(scale_factor=3, mode='bilinear', align_corners=False)
        in_t_9 = torch.zeros(1, 1, 9, 9)
        in_t_9[:, :, :4, :4].normal_()
        with warnings.catch_warnings(record=True) as w:
            out_t_9 = m(in_t_9)
            out_t_5 = m(in_t_9[:, :, :5, :5])
        self.assertEqual(out_t_9[:, :, :15, :15], out_t_5)

    def test_upsamplingNearest3d(self):
        m = nn.Upsample(size=4, mode='nearest')
        in_t = torch.ones(1, 1, 2, 2, 2)
        with warnings.catch_warnings(record=True) as w:
            out_t = m(Variable(in_t))
        self.assertEqual(torch.ones(1, 1, 4, 4, 4), out_t.data)

        input = torch.randn(1, 1, 2, 2, 2, requires_grad=True)
        gradcheck(lambda x: F.interpolate(x, 4, mode='nearest'), [input])

    def test_upsamplingTrilinear3d(self):
        for align_corners in [True, False]:
            kwargs = dict(mode='trilinear', align_corners=align_corners)

            # test float scale factor up & downsampling
            for scale_factor in [0.5, 1.5, 2]:
                m = nn.Upsample(scale_factor=scale_factor, **kwargs)
                in_t = torch.ones(1, 1, 2, 2, 2)
                out_size = int(math.floor(in_t.shape[-1] * scale_factor))
                with warnings.catch_warnings(record=True) as w:
                    out_t = m(in_t)
                self.assertEqual(torch.ones(1, 1, out_size, out_size, out_size), out_t.data)

                input = torch.randn(1, 1, 2, 2, 2, requires_grad=True)
                self.assertEqual(
                    F.interpolate(input, (out_size, out_size, out_size), **kwargs),
                    F.interpolate(input, scale_factor=scale_factor, **kwargs))
                gradcheck(lambda x: F.interpolate(x, out_size, **kwargs), [input])
                gradgradcheck(lambda x: F.interpolate(x, out_size, **kwargs), [input])

    def test_upsamplingTrilinear3d_spatial_invariance(self):
        m = nn.Upsample(scale_factor=3, mode='trilinear', align_corners=False)
        in_t_9 = torch.zeros(1, 1, 9, 9, 9)
        in_t_9[:, :, :4, :4, :4].normal_()
        with warnings.catch_warnings(record=True) as w:
            out_t_9 = m(in_t_9)
            out_t_5 = m(in_t_9[:, :, :5, :5, :5])
        self.assertEqual(out_t_9[:, :, :15, :15, :15], out_t_5)

    def test_interpolate(self):
        def _test_interpolate_helper(in_t, scale_factor, layer):
            out_size = int(math.floor(in_t.shape[-1] * scale_factor))
            dim = len(in_t.shape) - 2
            out_shape = [1, 1] + [out_size] * dim
            with warnings.catch_warnings(record=True) as w:
                out_t = m(in_t)
            self.assertEqual(torch.ones(out_shape), out_t)

            self.assertEqual(
                F.interpolate(in_t, (out_size,) * dim, **kwargs),
                F.interpolate(in_t, scale_factor=scale_factor, **kwargs))
            gradcheck(lambda x: F.interpolate(x, out_size, **kwargs), [in_t])
            gradgradcheck(lambda x: F.interpolate(x, out_size, **kwargs), [in_t])

        def _make_input(dim):
            size = [1, 1]
            size += [2] * dim
            return torch.ones(size, requires_grad=True)

        device_list = ['cpu']
        if TEST_CUDA:
            device_list.append('cuda')

        for device in device_list:
            for scale_factor in [0.5, 1.5, 2]:
                for mode in ['nearest', 'area']:
                    kwargs = dict(mode=mode)
                    m = nn.Upsample(scale_factor=scale_factor, **kwargs).to(device)
                    for input in [_make_input(1), _make_input(2), _make_input(3)]:
                        _test_interpolate_helper(input, scale_factor, m)

                for align_corners in [True, False]:
                    kwargs = dict(mode='linear', align_corners=align_corners)
                    m = nn.Upsample(scale_factor=scale_factor, **kwargs).to(device)
                    _test_interpolate_helper(_make_input(1), scale_factor, m)

                    kwargs = dict(mode='bilinear', align_corners=align_corners)
                    m = nn.Upsample(scale_factor=scale_factor, **kwargs).to(device)
                    _test_interpolate_helper(_make_input(2), scale_factor, m)

                    kwargs = dict(mode='bicubic', align_corners=align_corners)

                    def m(t):
                        return F.interpolate(t, scale_factor=scale_factor, **kwargs).to(device)
                    _test_interpolate_helper(_make_input(2), scale_factor, m)

                    kwargs = dict(mode='trilinear', align_corners=align_corners)
                    m = nn.Upsample(scale_factor=scale_factor, **kwargs).to(device)
                    _test_interpolate_helper(_make_input(3), scale_factor, m)

    def test_linear_broadcasting(self):
        m = nn.Linear(5, 8)
        inp = torch.randn(2, 3, 5)
        expected = m(inp.view(6, 5)).view(2, 3, 8)
        self.assertEqual(expected, m(inp))

    def test_bilinear(self):
        module = nn.Bilinear(10, 10, 8)
        input1 = torch.randn(4, 10, requires_grad=True)
        input2 = torch.randn(4, 10, requires_grad=True)
        grad_output = torch.randn(4, 8)

        res = module(input1, input2)
        expected = (torch.einsum("bi,kij,bj->bk", input1, module.weight, input2) +
                    module.bias)
        self.assertEqual(res, expected)
        grads = torch.autograd.grad(res, [module.weight, module.bias, input1, input2], grad_output)
        grads_expected = torch.autograd.grad(expected, [module.weight, module.bias, input1, input2], grad_output)
        for g, ge in zip(grads, grads_expected):
            self.assertEqual(g, ge)

    def test_bilinear_no_bias(self):
        module = nn.Bilinear(10, 10, 8)
        module_no_bias = nn.Bilinear(10, 10, 8, False)

        module.bias.data.zero_()
        module.weight.data.copy_(module_no_bias.weight)

        input1 = torch.randn(4, 10, requires_grad=True)
        input2 = torch.randn(4, 10, requires_grad=True)
        grad_output = torch.randn(4, 8)

        def run(net):
            input1.grad = input2.grad = None
            output = net(input1, input2)
            output.backward(grad_output)

            return output.data, input1.grad.data, input2.grad.data

        out, g1, g2 = run(module)
        out_nb, g1_nb, g2_nb = run(module_no_bias)

        self.assertEqual(out, out_nb)
        self.assertEqual(g1, g1_nb)
        self.assertEqual(g2, g2_nb)

        _assertGradAndGradgradChecks(self,
                                     lambda x1, x2: F.bilinear(x1, x2, module_no_bias.weight, module_no_bias.bias),
                                     (input1, input2))

    def test_bilinear_broadcasting(self):
        m = nn.Bilinear(5, 6, 8)
        input1 = torch.randn(2, 3, 5)
        input2 = torch.randn(2, 3, 6)
        expected = m(input1.view(6, 5), input2.view(6, 6)).view(2, 3, 8)
        self.assertEqual(expected, m(input1, input2))

    def test_conv_tbc(self):
        inp = torch.randn(9, 4, 5, requires_grad=True)
        weight = torch.randn(3, 5, 6, requires_grad=True)
        bias = torch.randn(6, requires_grad=True)

        gradcheck(lambda i, w, b, pad: F.conv_tbc(i, w, b, pad), (inp, weight, bias, 3))

    @staticmethod
    def _test_conv_noncontig_weights(self, device):
        for dim in (1, 2, 3):
            for grouped in (False, True):
                nc = 3
                groups = 3 if grouped else 1
                w = torch.randn([3] * dim, device=device)
                w = w.expand([nc, int(nc / groups)] + list(w.shape))
                w = w.detach().requires_grad_()
                x = torch.randn([1, nc] + ([5] * dim), device=device, requires_grad=True)
                y = getattr(F, 'conv{}d'.format(dim))(x, w, groups=groups)
                y.sum().backward()
                y = getattr(F, 'conv_transpose{}d'.format(dim))(x, w, groups=groups)
                y.sum().backward()

    def test_conv_noncontig_weights(self):
        self._test_conv_noncontig_weights(self, torch.device('cpu'))

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_conv_noncontig_weights_cuda(self):
        self._test_conv_noncontig_weights(self, torch.device('cuda'))

    @staticmethod
    def _test_conv_noncontig_weights_and_bias(self, device):
        # need floats to exercise https://github.com/pytorch/pytorch/issues/16018
        for bias in [True, False]:
            conv1 = nn.Conv2d(3, 64, kernel_size=7, stride=2, padding=3,
                              bias=bias).to(device, torch.float)

            input_nc = torch.randn((1, 3, 224, 224, 2), device=device, dtype=torch.float)[:, :, :, :, 1]
            input_c = input_nc.contiguous()

            weight_nc = torch.randn((64, 3, 7, 7, 2), device=device, dtype=torch.float)[:, :, :, :, 1]
            conv1.weight = nn.Parameter(weight_nc)
            weight_c = conv1.weight.contiguous()

            if bias:
                bias_nc = torch.randn((64, 2), device=device, dtype=torch.float)[:, 1]
                conv1.bias = nn.Parameter(bias_nc)
                bias_c = conv1.bias.contiguous()

            out1 = conv1(input_nc)
            conv1.weight = nn.Parameter(weight_c)
            if bias:
                conv1.bias = nn.Parameter(bias_c)
            out2 = conv1(input_c)
            self.assertEqual(out1, out2)

    def test_conv_noncontig_weights_and_bias(self):
        self._test_conv_noncontig_weights_and_bias(self, torch.device('cpu'))

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_conv_noncontig_weights_and_bias_cuda(self):
        self._test_conv_noncontig_weights_and_bias(self, torch.device('cuda'))

    def run_conv_double_back_test(self, kern, stride, padding, chan_in, chan_out, batch_size,
                                  inp_size, dilation, no_weight, groups=1, use_cuda=False,
                                  use_bias=True, dtype=torch.double):
        if use_cuda:
            device = torch.device("cuda")
        else:
            device = torch.device("cpu")

        x = torch.randn(batch_size, chan_in, inp_size, inp_size, device=device,
                        dtype=dtype, requires_grad=True)
        weight = torch.randn(chan_out, chan_in // groups, kern, kern, device=device,
                             dtype=dtype, requires_grad=not no_weight)
        if use_bias:
            bias = torch.randn(chan_out, device=device, dtype=dtype, requires_grad=True)
        else:
            bias = None

        def func(*inputs):
            if use_bias:
                lx, lweight, lbias = inputs
            else:
                lx, lweight = inputs
                lbias = None
            # We disable cudnn during forward to avoid finite difference imprecision issues
            with cudnn.flags(enabled=False):
                out = F.conv2d(lx, lweight, lbias, stride, padding, dilation, groups)
            return out

        if use_bias:
            inputs = x, weight, bias
        else:
            inputs = x, weight

        dummy_out = func(*inputs)
        grad_y = torch.randn_like(dummy_out, device=device, dtype=dtype, requires_grad=True)

        # Issue #15353: test mkldnn double backward, don't run gradgradcheck due
        # to imprecision issues
        if dtype == torch.float:
            g, = torch.autograd.grad(dummy_out.sum(), x, create_graph=True)
            return g.requires_grad

        return gradgradcheck(func, inputs, (grad_y,))

    def test_conv_double_backward(self):
        batch_size = 2
        for kern, inp_size, dilations in [(3, 6, [1, 2]), (3, 7, [1]), (4, 9, [1])]:
            for stride, padding, chan_in, chan_out, dilation in \
                    product([1, 2], [0, 1, 2], [2], [3], dilations):
                for no_weight in (True, False):
                    for dtype in (torch.float, torch.double):
                        result = self.run_conv_double_back_test(kern, stride,
                                                                padding, chan_in, chan_out,
                                                                batch_size, inp_size, dilation,
                                                                no_weight, dtype=dtype)
                        self.assertTrue(result,
                                        "Conv double backward test failed with parameters:" +
                                        "\nkern: " + str(kern) +
                                        "\nstride: " + str(stride) +
                                        "\npadding: " + str(padding) +
                                        "\nchan_in: " + str(chan_in) +
                                        "\nchan_out: " + str(chan_out) +
                                        "\nbatch_size: " + str(batch_size) +
                                        "\ninp_size: " + str(inp_size) +
                                        "\ndilation: " + str(dilation) +
                                        "\ndtype: " + str(dtype))

    def test_conv_double_backward_no_bias(self):
        kern = 3
        stride = 2
        chan_in, chan_out = 2, 4
        batch_size = 2
        inp_size = 5
        padding = 1
        dilation = 1
        no_weight = False
        use_bias = True
        result = self.run_conv_double_back_test(kern, stride,
                                                padding, chan_in, chan_out,
                                                batch_size, inp_size, dilation,
                                                no_weight, use_bias=use_bias)
        self.assertTrue(result,
                        "Conv double backward test failed with parameters:" +
                        "\nkern: " + str(kern) +
                        "\nstride: " + str(stride) +
                        "\npadding: " + str(padding) +
                        "\nchan_in: " + str(chan_in) +
                        "\nchan_out: " + str(chan_out) +
                        "\nbatch_size: " + str(batch_size) +
                        "\ninp_size: " + str(inp_size) +
                        "\ndilation: " + str(dilation))

    def test_conv_double_backward_groups(self):
        kern = 3
        stride = 1
        padding = 2
        chan_in, chan_out = 2, 4
        batch_size = 2
        inp_size = 6
        dilation = 1
        no_weight = False
        groups = 2
        result = self.run_conv_double_back_test(kern, stride,
                                                padding, chan_in * groups, chan_out * groups,
                                                batch_size, inp_size, dilation,
                                                no_weight, groups=groups)
        self.assertTrue(result,
                        "Conv double backward test failed with parameters:" +
                        "\nkern: " + str(kern) +
                        "\nstride: " + str(stride) +
                        "\npadding: " + str(padding) +
                        "\nchan_in: " + str(chan_in) +
                        "\nchan_out: " + str(chan_out) +
                        "\nbatch_size: " + str(batch_size) +
                        "\ninp_size: " + str(inp_size) +
                        "\ndilation: " + str(dilation) +
                        "\ngroups: " + str(groups))

    def test_conv_double_backward_stride(self):
        batch_size = 2

        # Cannot provide ggW when stride is > 1
        for kern, inp_size, dilations in [(3, 5, [1, 2]), (3, 7, [1])]:
            for stride, padding, chan_in, chan_out, dilation in product([2], [0, 1], [1], [2], dilations):
                no_weight = False
                self.run_conv_double_back_test(kern, stride,
                                               padding, chan_in, chan_out,
                                               batch_size, inp_size, dilation,
                                               no_weight)

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    def test_cudnn_noncontiguous_weight(self):
        # Noncontiguous weights must be contiguous() before being
        # passed to cuDNN
        input = Variable(torch.cuda.DoubleTensor([1, 1, 1]).view(1, 1, 3))
        weights1 = Variable(torch.cuda.DoubleTensor([1]).expand(1, 1, 2))
        weights2 = Variable(torch.cuda.DoubleTensor([1]).expand(1, 1, 2)).contiguous()
        self.assertEqual(F.conv1d(input, weights1, bias=None, stride=2, dilation=2),
                         F.conv1d(input, weights2, bias=None, stride=2, dilation=2))

    @unittest.skipIf(not TEST_CUDA, "CUDA unavailable")
    @repeat_test_for_types(DOUBLE_TENSORTYPES)
    def test_conv_double_backward_cuda(self, dtype=torch.double):
        # Double backward only runs with DoubleTensor due to precison reason
        batch_size = 1
        for kern, inp_size, dilations in [(3, 5, [1, 2]), (4, 9, [1])]:
            for stride, padding, chan_in, chan_out, dilation in product([1], [2], [2], [3], dilations):
                no_weight = stride == 2
                result = self.run_conv_double_back_test(kern, stride,
                                                        padding, chan_in, chan_out,
                                                        batch_size, inp_size, dilation,
                                                        no_weight, use_cuda=True, dtype=dtype)
                self.assertTrue(result,
                                "Conv double backward test failed with parameters:" +
                                "\nkern: " + str(kern) +
                                "\nstride: " + str(stride) +
                                "\npadding: " + str(padding) +
                                "\nchan_in: " + str(chan_in) +
                                "\nchan_out: " + str(chan_out) +
                                "\nbatch_size: " + str(batch_size) +
                                "\ninp_size: " + str(inp_size) +
                                "\ndilation: " + str(dilation))

    def run_grad_conv_test(self, func_forward, func_backward, dim=1, gradient='input'):
        for kern, inp_size in [(3, 6), (3, 7), (4, 9)]:
            for batch, stride, padding, chan_in, chan_out, dilation in \
                    product([1, 2], [1, 2], [0, 1, 2], [2], [3], [1]):

                for has_bias in [True, False]:
                    input_shape = [batch, chan_in]
                    weight_shape = [chan_out, chan_in]
                    for _ in range(dim):
                        input_shape.append(inp_size)
                        weight_shape.append(kern)

                    input = torch.randn(input_shape, requires_grad=True)
                    weight = torch.randn(weight_shape, requires_grad=True)
                    if has_bias:
                        bias = torch.randn([chan_out], requires_grad=True)
                    output = func_forward(input, weight, stride=stride, padding=padding, dilation=dilation, bias=bias)

                    gradient_o = torch.randn(output.shape)
                    gradient_w = torch.autograd.grad(output, input if (gradient == 'input') else weight, gradient_o)

                    self.assertAlmostEqual(gradient_w[0],
                                           func_backward(
                                               input_shape if (gradient == 'input') else input,
                                               weight_shape if (gradient == 'weight') else weight,
                                               gradient_o,
                                               stride=stride,
                                               padding=padding,
                                               dilation=dilation))

    def test_grad_conv1d_input(self):
        self.run_grad_conv_test(F.conv1d, F.grad.conv1d_input, 1, 'input')

    def test_grad_conv1d_weight(self):
        self.run_grad_conv_test(F.conv1d, F.grad.conv1d_weight, 1, 'weight')

    def test_grad_conv2d_input(self):
        self.run_grad_conv_test(F.conv2d, F.grad.conv2d_input, 2, 'input')

    def test_grad_conv2d_weight(self):
        self.run_grad_conv_test(F.conv2d, F.grad.conv2d_weight, 2, 'weight')

    def test_grad_conv3d_input(self):
        self.run_grad_conv_test(F.conv3d, F.grad.conv3d_input, 3, 'input')

    def test_grad_conv3d_weight(self):
        self.run_grad_conv_test(F.conv3d, F.grad.conv3d_weight, 3, 'weight')

    @unittest.skipIf(not torch._nnpack_available(), "NNPACK unavailable")
    def test_nnpack_conv(self):
        for kern, inp_size in [(3, 6), (3, 7), (4, 9)]:
            for batch, padding, chan_in, chan_out in \
                    product([1, 2], [0, 1, 2], [2], [3]):

                for has_bias in [True, False]:
                    input_shape = [batch, chan_in]
                    weight_shape = [chan_out, chan_in]
                    for _ in range(2):
                        input_shape.append(inp_size)
                        weight_shape.append(kern)

                    input = torch.randn(input_shape, requires_grad=True, dtype=torch.float)
                    weight = torch.randn(weight_shape, requires_grad=True, dtype=torch.float)
                    if has_bias:
                        bias = torch.randn([chan_out], requires_grad=True, dtype=torch.float)
                    output = torch._nnpack_spatial_convolution(input, weight, padding=padding, bias=bias)
                    output_expected = torch.nn.functional.conv2d(input, weight, padding=padding, bias=bias)
                    self.assertAlmostEqual(output, output_expected, delta=3e-4)

                    gradient_o = torch.randn(output.shape, dtype=torch.float)

                    grads = torch.autograd.grad(output, [input, weight], gradient_o)
                    grads_expected = torch.autograd.grad(output_expected, [input, weight], gradient_o)
                    for gr, gr_expected in zip(grads, grads_expected):
                        self.assertAlmostEqual(gr, gr_expected, delta=3e-4)

    def test_fold_invalid_arg(self):
        # input wrong dimension

        fold = nn.Fold(output_size=(4, 5), kernel_size=(2, 3))
        with self.assertRaisesRegex(NotImplementedError, r"Only 3D input Tensors are supported"):
            fold(torch.randn(1, 5))

        # input.size(1) not divisible by \prod(kernel_size)

        fold = nn.Fold(output_size=(4, 5), kernel_size=(2, 3))
        with self.assertRaisesRegex(RuntimeError, r"be divisible by the product of kernel_size"):
            fold(torch.randn(1, 5, 9))

        with self.assertRaisesRegex(RuntimeError, r"be divisible by the product of kernel_size"):
            fold(torch.randn(1, 19, 9))

        # input.size(2) not matching the total number of sliding blocks

        with self.assertRaisesRegex(RuntimeError, r"match the calculated number of sliding blocks"):
            fold = nn.Fold(output_size=(4, 5), kernel_size=(2, 3))
            fold(torch.randn(1, 6, 10))

        with self.assertRaisesRegex(RuntimeError, r"match the calculated number of sliding blocks"):
            fold = nn.Fold(output_size=(4, 5), kernel_size=(2, 3), stride=(2, 2))
            fold(torch.randn(1, 6, 5))

        with self.assertRaisesRegex(RuntimeError, r"match the calculated number of sliding blocks"):
            fold = nn.Fold(output_size=(4, 5), kernel_size=(2, 3), stride=(2, 2), dilation=(1, 2), padding=(2, 0))
            fold(torch.randn(1, 6, 5))  # should be 4 * 1 = 4 sliding blocks

    def test_unfold_invalid_arg(self):
        # input wrong dimension

        unfold = nn.Unfold(kernel_size=(2, 3))
        with self.assertRaisesRegex(NotImplementedError, r"Only 4D input Tensors are supported"):
            unfold(torch.randn(1, 5, 2))

        # calculated output shape is too small

        with self.assertRaisesRegex(RuntimeError, r"too small \(non-positive\)"):
            unfold = nn.Unfold(kernel_size=(2, 3))
            unfold(torch.randn(1, 2, 2, 2))

        with self.assertRaisesRegex(RuntimeError, r"too small \(non-positive\)"):
            unfold = nn.Unfold(kernel_size=(5, 3), padding=(1, 1))
            unfold(torch.randn(1, 2, 2, 3))

        with self.assertRaisesRegex(RuntimeError, r"too small \(non-positive\)"):
            unfold = nn.Unfold(kernel_size=(1, 3), padding=(1, 1), dilation=(1, 2))
            unfold(torch.randn(1, 2, 2, 2))

    def test_softmin(self):
        x = torch.randn(2, 16)
        self.assertEqual(F.softmin(x, 1), F.softmax(-x, 1))
        self.assertEqual(F.softmin(x, 0), F.softmax(-x, 0))

    def test_adaptive_log_softmax(self):
        # args validation
        with self.assertRaises(ValueError):
            _ = nn.AdaptiveLogSoftmaxWithLoss(16, 20, [5, 15, 15], div_value=2.)

        with self.assertRaises(ValueError):
            _ = nn.AdaptiveLogSoftmaxWithLoss(16, 20, [5, 15, 10], div_value=2.)

        with self.assertRaises(ValueError):
            _ = nn.AdaptiveLogSoftmaxWithLoss(16, 20, [5, 10, 25], div_value=2.)

        with self.assertRaisesRegex(ValueError, "cutoffs should be a sequence of unique,"):
            _ = nn.AdaptiveLogSoftmaxWithLoss(16, 20, [5, 10, 20], div_value=2.)

        # not raise
        _ = nn.AdaptiveLogSoftmaxWithLoss(16, 20, [5, 10, 19], div_value=2.)

        # input shapes
        with self.assertRaisesRegex(RuntimeError, r"Input and target should have the same size"):
            asfm = nn.AdaptiveLogSoftmaxWithLoss(16, 20, [5, 10, 15], div_value=2.)
            x = torch.randn(2, 16)
            y = torch.tensor([0, 5, 10])
            asfm(x, y)

        # out-of-bound targets
        with self.assertRaisesRegex(RuntimeError, r"Target values should be in"):
            asfm = nn.AdaptiveLogSoftmaxWithLoss(16, 20, [5, 10, 15], div_value=2.)
            x = torch.randn(2, 16)
            y = torch.tensor([0, 20])
            asfm(x, y)

        # cluster sizes
        asfm = nn.AdaptiveLogSoftmaxWithLoss(16, 20, [5, 10, 15], div_value=2.)
        x = torch.randn(2, 16)
        y = torch.tensor([0, 17])

        self.assertEqual(asfm.head.weight.size(), (5 + 3, 16))   # 5 targets in head, 3 clusters, dimensionality 16
        self.assertEqual(asfm.tail[0][1].weight.size(), (5, 8))  # 5 targets in this cluster, dimensionality 8
        self.assertEqual(asfm.tail[1][1].weight.size(), (5, 4))
        self.assertEqual(asfm.tail[2][1].weight.size(), (5, 2))

        self.assertEqual(asfm(x, y).output.size(), (2, ))

        # log_probs actually returns log_proba
        asfm = nn.AdaptiveLogSoftmaxWithLoss(8, 4, [2], div_value=2.)
        x = torch.randn(4, 8)
        logprob_out = asfm.log_prob(x)

        self.assertEqual(torch.exp(logprob_out).data.sum(1), torch.ones(4))

        # forward returns the same thing as log_probs
        for v in [0, 1, 2, 3]:
            y = torch.full((4,), v, dtype=torch.long)
            out, loss = asfm(x, y)

            self.assertEqual(out, logprob_out.gather(1, y.unsqueeze(1)).squeeze())
            self.assertEqual(loss, F.nll_loss(logprob_out, y))

        # predict
        x = torch.randn(64, 8).abs_()

        # argmax in shortlist
        asfm = nn.AdaptiveLogSoftmaxWithLoss(8, 10, [4, 8], div_value=2., head_bias=True)
        asfm.head.weight.data.abs_()
        asfm.head.bias.data.abs_()
        asfm.head.weight.data[asfm.shortlist_size:, :].zero_()

        out = asfm.predict(x)
        self.assertEqual(out, asfm.log_prob(x).argmax(dim=1))

        # argmax outside of shortlist
        asfm = nn.AdaptiveLogSoftmaxWithLoss(8, 10, [4, 8], div_value=2., head_bias=True)
        asfm.head.weight.data.abs_()
        asfm.head.bias.data.abs_()
        asfm.head.weight.data[:asfm.shortlist_size, :].zero_()

        out = asfm.predict(x)
        self.assertEqual(out, asfm.log_prob(x).argmax(dim=1))

        # half of the argmax in shortlist, half in clusters
        asfm = nn.AdaptiveLogSoftmaxWithLoss(8, 10, [4, 8], div_value=2., head_bias=True)
        asfm.head.weight.data.abs_()
        asfm.head.bias.data.abs_()

        x[:32, :asfm.shortlist_size].zero_()
        x[32:, asfm.shortlist_size:].zero_()

        asfm.head.weight.data[:asfm.shortlist_size, asfm.shortlist_size:].zero_()
        asfm.head.weight.data[asfm.shortlist_size:, :asfm.shortlist_size].zero_()

        out = asfm.predict(x)
        self.assertEqual(out, asfm.log_prob(x).argmax(dim=1))


class TestNNInit(TestCase):
    def setUp(self):
        super(TestNNInit, self).setUp()
        random.seed(123)

    def _is_normal(self, tensor, mean, std):
        samples = tensor.view(-1).tolist()
        p_value = stats.kstest(samples, 'norm', args=(mean, std))[1]
        return p_value > 0.0001

    def _is_uniform(self, tensor, a, b):
        samples = tensor.view(-1).tolist()
        p_value = stats.kstest(samples, 'uniform', args=(a, (b - a)))[1]
        return p_value > 0.0001

    def _create_random_nd_tensor(self, dims, size_min, size_max):
        size = [random.randint(size_min, size_max) for _ in range(dims)]
        tensor = torch.zeros(size)
        return tensor

    def _random_float(self, a, b):
        return (b - a) * random.random() + a

    def test_calculate_gain_linear(self):
        for fn in ['linear', 'conv1d', 'conv2d', 'conv3d', 'conv_transpose2d', 'conv_transpose2d', 'conv_transpose3d']:
            gain = init.calculate_gain(fn)
            self.assertEqual(gain, 1)

    def test_calculate_gain_nonlinear(self):
        for fn in ['sigmoid', 'tanh', 'relu', 'leaky_relu']:
            gain = init.calculate_gain(fn)
            if fn == 'sigmoid':
                self.assertEqual(gain, 1)
            elif fn == 'tanh':  # 5 / 3
                self.assertEqual(gain, 1.6666666666666667)
            elif fn == 'relu':  # sqrt(2)
                self.assertEqual(gain, 1.4142135623730951)
            elif fn == 'leaky_relu':  # sqrt(2 / 1 + slope^2))
                self.assertEqual(gain, 1.4141428569978354)

    def test_calculate_gain_leaky_relu(self):
        for param in [None, 0, 0.01, 10]:
            gain = init.calculate_gain('leaky_relu', param)
            if param is None:  # Default slope is 0.01
                self.assertEqual(gain, 1.4141428569978354)
            elif param == 0:  # No slope = same gain as normal ReLU
                self.assertEqual(gain, 1.4142135623730951)
            elif param == 0.01:
                self.assertEqual(gain, 1.4141428569978354)
            elif param == 10:
                self.assertEqual(gain, 0.14071950894605836)

    def test_calculate_gain_leaky_relu_only_accepts_numbers(self):
        for param in [True, [1], {'a': 'b'}]:
            with self.assertRaises(ValueError):
                init.calculate_gain('leaky_relu', param)

    def test_calculate_gain_only_accepts_valid_nonlinearities(self):
        for n in [2, 5, 25]:
            # Generate random strings of lengths that definitely aren't supported
            random_string = ''.join([random.choice(string.ascii_lowercase) for i in range(n)])
            with self.assertRaises(ValueError):
                init.calculate_gain(random_string)

    @unittest.skipIf(not TEST_SCIPY, "Scipy not found.")
    def test_uniform(self):
        for dims in [1, 2, 4]:
            input_tensor = self._create_random_nd_tensor(dims, size_min=30, size_max=50)
            a = self._random_float(-3, 3)
            b = a + self._random_float(1, 5)
            init.uniform_(input_tensor, a=a, b=b)
            assert self._is_uniform(input_tensor, a, b)

    @unittest.skipIf(not TEST_SCIPY, "Scipy not found.")
    def test_normal(self):
        for dims in [1, 2, 4]:
            input_tensor = self._create_random_nd_tensor(dims, size_min=30, size_max=50)
            mean = self._random_float(-3, 3)
            std = self._random_float(1, 5)
            init.normal_(input_tensor, mean=mean, std=std)

            assert self._is_normal(input_tensor, mean, std)

    def test_constant(self):
        for dims in [1, 2, 4]:
            input_tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=5)
            val = self._random_float(1, 10)
            init.constant_(input_tensor, val)

            self.assertEqual(input_tensor, input_tensor.clone().fill_(val))

    def test_ones_and_zeros(self):
        for init_fn_, val in zip([init.ones_, init.zeros_], [1, 0]):
            for dims in [1, 2, 4]:
                input_tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=5)
                init_fn_(input_tensor)

                self.assertEqual(input_tensor, input_tensor.clone().fill_(val))

    def test_eye(self):
        input_tensor = self._create_random_nd_tensor(2, size_min=1, size_max=5)
        init.eye_(input_tensor)

        # Check every single element
        for i in range(input_tensor.size(0)):
            for j in range(input_tensor.size(1)):
                if i == j:
                    assert input_tensor[i][j] == 1
                else:
                    assert input_tensor[i][j] == 0

    def test_eye_only_works_on_2d_inputs(self):
        for dims in [1, 3]:
            with self.assertRaises(ValueError):
                tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=3)
                init.eye_(tensor)

    def test_max_unpool(self):
        # Test 1D
        output, indices = F.max_pool1d(torch.randn([1, 1, 4]), 2, stride=2, return_indices=True)
        self.assertEqual(F.max_unpool1d(output, indices, 2), F.max_unpool1d(output, indices, 2, stride=2))

        # Test list / tuple passed as argument to max_unpool1d
        input = torch.randn([1, 1, 5])
        output, indices = F.max_pool1d(input, 2, stride=2, return_indices=True)
        self.assertEqual(F.max_unpool1d(output, indices, 2, stride=2, output_size=input.shape),
                         F.max_unpool1d(output, indices, 2, stride=2, output_size=input.size()))

        # Test 2D
        output, indices = F.max_pool2d(torch.randn([1, 1, 4, 4]), 2, stride=2, return_indices=True)
        self.assertEqual(F.max_unpool2d(output, indices, 2), F.max_unpool2d(output, indices, 2, stride=2))

        # Test 3D
        output, indices = F.max_pool3d(torch.randn([4, 4, 4, 4, 4]), 2, stride=2, return_indices=True)
        self.assertEqual(F.max_unpool3d(output, indices, 2), F.max_unpool3d(output, indices, 2, stride=2))

    def test_dirac_properties(self):
        for dims in [3, 4, 5]:
            input_tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=5)
            init.dirac_(input_tensor)

            c_out, c_in = input_tensor.size(0), input_tensor.size(1)
            min_d = min(c_out, c_in)
            # Check number of nonzeros is equivalent to smallest dim
            assert torch.nonzero(input_tensor).size(0) == min_d
            # Check sum of values (can have precision issues, hence assertEqual) is also equivalent
            self.assertEqual(input_tensor.sum(), min_d)

    def test_dirac_identity(self):
        batch, in_c, out_c, size, kernel_size = 8, 3, 4, 5, 3
        # Test 1D
        input_var = torch.randn(batch, in_c, size)
        filter_var = torch.zeros(out_c, in_c, kernel_size)
        init.dirac_(filter_var)
        output_var = F.conv1d(input_var, filter_var)
        input_tensor, output_tensor = input_var.data, output_var.data  # Variables do not support nonzero
        self.assertEqual(input_tensor[:, :, 1:-1], output_tensor[:, :in_c, :])  # Assert in_c outputs are preserved
        assert torch.nonzero(output_tensor[:, in_c:, :]).numel() == 0  # Assert extra outputs are 0

        # Test 2D
        input_var = torch.randn(batch, in_c, size, size)
        filter_var = torch.zeros(out_c, in_c, kernel_size, kernel_size)
        init.dirac_(filter_var)
        output_var = F.conv2d(input_var, filter_var)
        input_tensor, output_tensor = input_var.data, output_var.data
        self.assertEqual(input_tensor[:, :, 1:-1, 1:-1], output_tensor[:, :in_c, :, :])
        assert torch.nonzero(output_tensor[:, in_c:, :, :]).numel() == 0

        # Test 3D
        input_var = torch.randn(batch, in_c, size, size, size)
        filter_var = torch.zeros(out_c, in_c, kernel_size, kernel_size, kernel_size)
        init.dirac_(filter_var)
        output_var = F.conv3d(input_var, filter_var)
        input_tensor, output_tensor = input_var.data, output_var.data
        self.assertEqual(input_tensor[:, :, 1:-1, 1:-1, 1:-1], output_tensor[:, :in_c, :, :])
        assert torch.nonzero(output_tensor[:, in_c:, :, :, :]).numel() == 0

    def test_dirac_only_works_on_3_4_5d_inputs(self):
        for dims in [1, 2, 6]:
            with self.assertRaises(ValueError):
                tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=3)
                init.dirac_(tensor)

    def test_xavier_uniform_errors_on_inputs_smaller_than_2d(self):
        for dims in [0, 1]:
            tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=1)
            with self.assertRaises(ValueError):
                init.xavier_uniform_(tensor)

    def test_xavier_normal_errors_on_inputs_smaller_than_2d(self):
        for dims in [0, 1]:
            tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=1)
            with self.assertRaises(ValueError):
                init.xavier_normal_(tensor)

    @unittest.skipIf(not TEST_SCIPY, "Scipy not found.")
    def test_xavier_uniform(self):
        for use_gain in [True, False]:
            for dims in [2, 4]:
                input_tensor = self._create_random_nd_tensor(dims, size_min=20, size_max=25)
                gain = 1

                if use_gain:
                    gain = self._random_float(0.1, 2)
                    init.xavier_uniform_(input_tensor, gain=gain)
                else:
                    init.xavier_uniform_(input_tensor)

                fan_in = input_tensor.size(1)
                fan_out = input_tensor.size(0)
                if input_tensor.dim() > 2:
                    fan_in *= input_tensor[0, 0].numel()
                    fan_out *= input_tensor[0, 0].numel()

                expected_std = gain * math.sqrt(2.0 / (fan_in + fan_out))
                bounds = expected_std * math.sqrt(3)
                assert self._is_uniform(input_tensor, -bounds, bounds)

    @unittest.skipIf(not TEST_SCIPY, "Scipy not found.")
    def test_xavier_normal(self):
        for use_gain in [True, False]:
            for dims in [2, 4]:
                input_tensor = self._create_random_nd_tensor(dims, size_min=20, size_max=25)
                gain = 1

                if use_gain:
                    gain = self._random_float(0.1, 2)
                    init.xavier_normal_(input_tensor, gain=gain)
                else:
                    init.xavier_normal_(input_tensor)

                fan_in = input_tensor.size(1)
                fan_out = input_tensor.size(0)
                if input_tensor.dim() > 2:
                    fan_in *= input_tensor[0, 0].numel()
                    fan_out *= input_tensor[0, 0].numel()

                expected_std = gain * math.sqrt(2.0 / (fan_in + fan_out))
                assert self._is_normal(input_tensor, 0, expected_std)

    def test_kaiming_uniform_errors_on_inputs_smaller_than_2d(self):
        for dims in [0, 1]:
            with self.assertRaises(ValueError):
                tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=1)
                init.kaiming_uniform_(tensor)

    def test_kaiming_normal_errors_on_inputs_smaller_than_2d(self):
        for dims in [0, 1]:
            with self.assertRaises(ValueError):
                tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=1)
                init.kaiming_normal_(tensor)

    @unittest.skipIf(not TEST_SCIPY, "Scipy not found.")
    def test_kaiming_uniform(self):
        for use_a in [True, False]:
            for dims in [2, 4]:
                for mode in ['fan_in', 'fan_out']:
                    input_tensor = self._create_random_nd_tensor(dims, size_min=20, size_max=25)
                    if use_a:
                        a = self._random_float(0.1, 2)
                        init.kaiming_uniform_(input_tensor, a=a, mode=mode)
                    else:
                        a = 0
                        init.kaiming_uniform_(input_tensor, mode=mode)

                    fan_in = input_tensor.size(1)
                    fan_out = input_tensor.size(0)
                    if input_tensor.dim() > 2:
                        fan_in *= input_tensor[0, 0].numel()
                        fan_out *= input_tensor[0, 0].numel()

                    if mode == 'fan_in':
                        n = fan_in
                    else:
                        n = fan_out

                    expected_std = math.sqrt(2.0 / ((1 + a**2) * n))
                    bounds = expected_std * math.sqrt(3.0)
                    assert self._is_uniform(input_tensor, -bounds, bounds)

    @unittest.skipIf(not TEST_SCIPY, "Scipy not found.")
    def test_kaiming_normal(self):
        for use_a in [True, False]:
            for dims in [2, 4]:
                for mode in ['fan_in', 'fan_out']:
                    input_tensor = self._create_random_nd_tensor(dims, size_min=20, size_max=25)
                    if use_a:
                        a = self._random_float(0.1, 2)
                        init.kaiming_normal_(input_tensor, a=a, mode=mode)
                    else:
                        a = 0
                        init.kaiming_normal_(input_tensor, mode=mode)

                    fan_in = input_tensor.size(1)
                    fan_out = input_tensor.size(0)
                    if input_tensor.dim() > 2:
                        fan_in *= input_tensor[0, 0].numel()
                        fan_out *= input_tensor[0, 0].numel()

                    if mode == 'fan_in':
                        n = fan_in
                    else:
                        n = fan_out

                    expected_std = math.sqrt(2.0 / ((1 + a**2) * n))
                    assert self._is_normal(input_tensor, 0, expected_std)

    def test_sparse_only_works_on_2d_inputs(self):
        for dims in [1, 3]:
            with self.assertRaises(ValueError):
                sparsity = self._random_float(0.1, 0.9)
                tensor = self._create_random_nd_tensor(dims, size_min=1, size_max=3)
                init.sparse_(tensor, sparsity)

    @unittest.skipIf(not TEST_SCIPY, "Scipy not found.")
    def test_sparse_default_std(self):
        for use_random_std in [True, False]:
            input_tensor = self._create_random_nd_tensor(2, size_min=30, size_max=35)
            rows, cols = input_tensor.size(0), input_tensor.size(1)
            sparsity = self._random_float(0.1, 0.2)

            std = 0.01  # default std
            if use_random_std:
                std = self._random_float(0.01, 0.2)
                init.sparse_(input_tensor, sparsity=sparsity, std=std)
            else:
                init.sparse_(input_tensor, sparsity=sparsity)

            for col_idx in range(input_tensor.size(1)):
                column = input_tensor[:, col_idx]
                assert column[column == 0].nelement() >= math.ceil(sparsity * rows)

            assert self._is_normal(input_tensor[input_tensor != 0], 0, std)

    @skipIfNoLapack
    def test_orthogonal(self):
        for use_gain in [True, False]:
            for tensor_size in [[3, 4], [4, 3], [20, 2, 3, 4], [2, 3, 4, 5]]:
                input_tensor = torch.zeros(tensor_size)
                gain = 1.0

                if use_gain:
                    gain = self._random_float(0.1, 2)
                    init.orthogonal_(input_tensor, gain=gain)
                else:
                    init.orthogonal_(input_tensor)

                rows, cols = tensor_size[0], reduce(mul, tensor_size[1:])
                flattened_tensor = input_tensor.view(rows, cols)
                if rows > cols:
                    self.assertEqual(torch.mm(flattened_tensor.t(), flattened_tensor),
                                     torch.eye(cols) * gain ** 2, prec=1e-6)
                else:
                    self.assertEqual(torch.mm(flattened_tensor, flattened_tensor.t()),
                                     torch.eye(rows) * gain ** 2, prec=1e-6)

    def test_deprecation(self):
        x = torch.randn(3, 3)

        def fn():
            init.normal(x)
        self.assertWarnsRegex(fn, 'deprecated', 'methods not suffixed with underscore should be deprecated')


def add_test(test, decorator=None):
    def add(test_name, fn):
        if hasattr(TestNN, test_name):
            raise RuntimeError('Found two tests with the same name: ' + test_name)
        if decorator is not None:
            fn = decorator(fn)
        setattr(TestNN, test_name, fn)

    test_name = test.get_name()
    add(test_name, lambda self, test=test: test(self))
    cuda_test_name = test_name + '_cuda'
    # With dtype enable, it's good enough to test against three floating types
    kwargs = {}
    if 'extra_args' in get_function_arglist(test.test_cuda):
        kwargs['extra_args'] = test.extra_args

    if 'dtype' in get_function_arglist(test.test_cuda):
        add(cuda_test_name + '_float', lambda self,
            test=test, kwargs=kwargs: test.test_cuda(self, dtype=torch.float, **kwargs))
        add(cuda_test_name + '_double', lambda self,
            test=test, kwargs=kwargs: test.test_cuda(self, dtype=torch.double, **kwargs))

        def test_half(self, test=test, kwargs=kwargs):
            test.test_cuda(self, dtype=torch.half, **kwargs)
        if getattr(test, 'check_half', True):
            add(cuda_test_name + '_half', test_half)
    else:
        add(cuda_test_name, lambda self, test=test, kwargs=kwargs: test.test_cuda(self, **kwargs))


new_criterion_tests = [
    dict(
        module_name='BCEWithLogitsLoss',
        input_fn=lambda: torch.rand(15, 10).clamp_(1e-2, 1 - 1e-2),
        target_fn=lambda: torch.randn(15, 10).gt(0).double(),
    ),
    dict(
        module_name='BCEWithLogitsLoss',
        constructor_args=(torch.rand(10),),
        input_fn=lambda: torch.rand(15, 10).clamp_(1e-2, 1 - 1e-2),
        target_fn=lambda: torch.randn(15, 10).gt(0).double(),
        desc='weights',
    ),
    dict(
        module_name='BCEWithLogitsLoss',
        constructor_args=(torch.rand(()),),
        input_fn=lambda: torch.rand(()).clamp_(1e-2, 1 - 1e-2),
        target_fn=lambda: torch.randn(()).gt(0).double(),
        desc='scalar_weights'
    ),
    dict(
        module_name='NLLLoss',
        input_size=(2, 3, 5, 5),
        target_fn=lambda: torch.rand(2, 5, 5).mul(3).floor().long(),
        reference_fn=lambda i, t, m:
            loss_reference_fns['NLLLossNd'](i, t, reduction=get_reduction(m)),
        check_sum_reduction=True,
        desc='2d',
    ),
    dict(
        module_name='NLLLoss',
        constructor_args_fn=lambda: (torch.rand(3),),
        input_size=(2, 3, 5, 5),
        target=torch.rand(2, 5, 5).mul(3).floor().long(),
        reference_fn=lambda i, t, m:
            loss_reference_fns['NLLLossNd'](i, t, weight=get_weight(m)),
        desc='2d_weights',
    ),
    dict(
        module_name='NLLLoss',
        constructor_args=(None, None, 1),
        input_size=(2, 3, 5, 5),
        target_fn=lambda: torch.rand(2, 5, 5).mul(3).floor().long(),
        reference_fn=lambda i, t, m:
            loss_reference_fns['NLLLossNd'](i, t, ignore_index=1),
        desc='2d_ignore_index',
    ),
    dict(
        module_name='NLLLoss',
        input_size=(2, 3, 5, 5, 2, 2),
        target_fn=lambda: torch.rand(2, 5, 5, 2, 2).mul(3).floor().long(),
        reference_fn=lambda i, t, m:
            loss_reference_fns['NLLLossNd'](i, t, reduction=get_reduction(m)),
        check_sum_reduction=True,
        desc='higher_dim',
    ),
    dict(
        module_name='NLLLoss',
        input_size=(2, 3, 5),
        target_fn=lambda: torch.rand(2, 5).mul(3).floor().long(),
        reference_fn=lambda i, t, m:
            loss_reference_fns['NLLLossNd'](i, t, reduction=get_reduction(m)),
        check_sum_reduction=True,
        desc='dim_is_3',
    ),
    dict(
        module_name='PoissonNLLLoss',
        input_size=(2, 3, 4, 5),
        target_fn=lambda: torch.randn(2, 3, 4, 5).floor_().abs_(),
        desc='no_full_loss',  # without sterling approx
    ),
    dict(
        module_name='PoissonNLLLoss',
        constructor_args=(False,),
        input_fn=lambda: torch.randn(2, 3, 4, 5).abs_().add_(0.001),
        target_fn=lambda: torch.randn(2, 3, 4, 5).floor_().abs_(),
        desc='full_loss',  # with sterling approx
    ),
    dict(
        module_name='L1Loss',
        input_size=(),
        target_size=(),
        reference_fn=lambda i, t, _: 1. / i.numel() * (i - t).abs().sum(),
        desc='scalar',
    ),
    dict(
        module_name='KLDivLoss',
        input_fn=lambda: torch.rand(()).log(),
        target_fn=lambda: torch.rand(()),
        reference_fn=lambda i, t, m:
            kldivloss_reference(i, t, get_reduction(m)),
        check_sum_reduction=True,
        desc='scalar',
    ),
    dict(
        module_name='MSELoss',
        input_size=(),
        target_size=(),
        reference_fn=lambda i, t, m: ((i - t).abs().pow(2).sum() /
                                      (i.numel() if get_reduction(m) == 'mean' else 1)),
        check_sum_reduction=True,
        desc='scalar'
    ),
    dict(
        module_name='MSELoss',
        input_fn=lambda: torch.ones(5, 68, 64, 64, dtype=torch.float) / 10,
        target_fn=lambda: torch.zeros(5, 68, 64, 64, dtype=torch.float),
        reference_fn=lambda i, t, m: ((i - t).abs().pow(2).sum() /
                                      (i.numel() if get_reduction(m) == 'mean' else 1)),
        check_forward_only=True,
        desc='prec',
    ),
    dict(
        module_name='BCELoss',
        constructor_args_fn=lambda: (torch.rand(()),),
        input_fn=lambda: torch.rand(()).clamp_(1e-2, 1 - 1e-2),
        target_fn=lambda: torch.rand(()).gt(0).double(),
        reference_fn=lambda i, t, m: -((t * i.log() + (1 - t) * (1 - i).log()) * get_weight(m)).sum() /
            (i.numel() if get_reduction(m) == 'mean' else 1),
        desc='scalar_weights',
        check_gradgrad=False,
    ),
    dict(
        module_name='HingeEmbeddingLoss',
        constructor_args=(0.5,),
        input_size=(),
        target_fn=lambda: torch.randn(()).gt(0).double().mul_(2).sub(1),
        desc='scalar_margin',
        check_sum_reduction=True,
    ),
    dict(
        module_name='SmoothL1Loss',
        input_size=(),
        target_size=(),
        check_sum_reduction=True,
        reference_fn=lambda i, t, m:
            smoothl1loss_reference(i, t, reduction=get_reduction(m)),
        desc='scalar',
    ),
    dict(
        module_name='MultiLabelSoftMarginLoss',
        constructor_args=(torch.rand(10),),
        input_fn=lambda: torch.randn(5, 10),
        target_fn=lambda: torch.rand(5, 10).mul(2).floor(),
        reference_fn=lambda i, t, m: -((t * i.sigmoid().log() + (1 - t) * (-i).sigmoid().log()) * get_weight(m)).sum() /
            (i.numel() if get_reduction(m) == 'mean' else i.size(1) if get_reduction(m) == 'sum' else 1),
        desc='weights',
        check_sum_reduction=True,
        check_gradgrad=False,
    ),
    dict(
        module_name='CTCLoss',
        constructor_args=(14,),  # blank=14
        extra_args=([50, 50, 50], [30, 25, 20]),  # input_lengths, target_lengths
        input_fn=lambda: torch.randn(50, 3, 15).log_softmax(2),
        target_fn=lambda: torch.randint(0, 14, (3, 30), dtype=torch.long),
        reference_fn=lambda i, t, il, tl, m:
            ctcloss_reference(i, t, il, tl, blank=14, reduction=get_reduction(m)),
        check_sum_reduction=True,
        check_gradgrad=False,
        check_half=False,
    ),
    dict(
        module_name='CTCLoss',
        desc='1d_target',
        constructor_args=(14,),  # blank=14
        extra_args=([50, 50, 50], [30, 25, 20]),  # input_lengths, target_lengths
        input_fn=lambda: torch.randn(50, 3, 15).log_softmax(2),
        target_fn=lambda: torch.randint(0, 14, (3, 30), dtype=torch.long),
        reference_fn=lambda i, t, il, tl, m:
            ctcloss_reference(i, t, il, tl, blank=14, reduction=get_reduction(m)),
        check_sum_reduction=True,
        check_gradgrad=False,
        check_half=False,
    ),
    dict(
        module_name='CTCLoss',
        desc='2d_int_target',
        constructor_args=(0,),  # blank=0
        extra_args=([50, 50, 50], [30, 25, 20]),  # input_lengths, target_lengths
        input_fn=lambda: torch.randn(50, 3, 15).log_softmax(2),
        target_fn=lambda: torch.randint(1, 15, (3, 30), dtype=torch.int),
        reference_fn=lambda i, t, il, tl, m:
            ctcloss_reference(i, t, il, tl, blank=0, reduction=get_reduction(m)),
        check_sum_reduction=True,
        check_gradgrad=False,
        check_half=False,
        convert_target=False,
    ),
    dict(
        module_name='CTCLoss',
        desc='2d_lengths_tensors',
        constructor_args=(0,),  # blank=0
        extra_args=(torch.tensor([50, 50, 50]), torch.tensor([30, 25, 20])),  # input_lengths, target_lengths
        input_fn=lambda: torch.randn(50, 3, 15).log_softmax(2),
        target_fn=lambda: torch.randint(1, 15, (3, 30), dtype=torch.int),
        reference_fn=lambda i, t, il, tl, m:
            ctcloss_reference(i, t, il, tl, blank=0, reduction=get_reduction(m)),
        check_sum_reduction=True,
        check_gradgrad=False,
        check_half=False,
        convert_target=False,
    ),
]


for test_params in module_tests + new_module_tests:
    # TODO: CUDA is not implemented yet
    if 'constructor' not in test_params:
        name = test_params.pop('module_name')
        test_params['constructor'] = getattr(nn, name)
    decorator = test_params.pop('decorator', None)
    test = NewModuleTest(**test_params)
    add_test(test, decorator)
    if 'check_eval' in test_params:
        # create a new test that is identical but that sets module.training to False
        desc = test_params.get('desc', None)
        test_params['desc'] = 'eval' if desc is None else desc + '_eval'

        def gen_eval_constructor(constructor):
            def eval_constructor(*args, **kwargs):
                cons = constructor(*args, **kwargs)
                cons.training = False
                return cons
            eval_constructor.__name__ = constructor.__name__
            return eval_constructor

        test_params['constructor'] = gen_eval_constructor(test_params['constructor'])
        test = NewModuleTest(**test_params)
        add_test(test, decorator)

for test_params in criterion_tests + new_criterion_tests:
    name = test_params.pop('module_name')
    test_params['constructor'] = getattr(nn, name)
    test = NewCriterionTest(**test_params)
    decorator = test_params.pop('decorator', None)
    add_test(test, decorator)
    if 'check_sum_reduction' in test_params:
        desc = test_params.get('desc', None)
        test_params['desc'] = 'sum_reduction' if desc is None else desc + '_sum_reduction'

        def gen_sum_reduction_constructor(constructor):
            def sum_reduction_constructor(*args, **kwargs):
                cons = constructor(*args, reduction='sum', **kwargs)
                return cons
            sum_reduction_constructor.__name__ = constructor.__name__
            return sum_reduction_constructor

        test_params['constructor'] = gen_sum_reduction_constructor(test_params['constructor'])
        test = NewCriterionTest(**test_params)
        add_test(test, decorator)


class UnpoolingNet(nn.Module):
    def __init__(self, pool, unpool):
        super(UnpoolingNet, self).__init__()
        self.pool = pool
        self.unpool = unpool

    def forward(self, input):
        return self.unpool(*self.pool(input))


add_test(NewModuleTest(
    constructor=lambda: UnpoolingNet(
        nn.MaxPool1d(2, return_indices=True),
        nn.MaxUnpool1d(2)),
    input_size=(1, 1, 4),
    fullname='MaxUnpool1d_net',))
add_test(NewModuleTest(
    constructor=lambda: UnpoolingNet(
        nn.MaxPool2d(2, return_indices=True),
        nn.MaxUnpool2d(2)),
    input_size=(1, 1, 2, 4),
    fullname='MaxUnpool2d_net',))
add_test(NewModuleTest(
    constructor=lambda: UnpoolingNet(
        nn.MaxPool3d(2, return_indices=True),
        nn.MaxUnpool3d(2)),
    input_size=(1, 1, 2, 4, 6),
    fullname='MaxUnpool3d_net',
    check_gradgrad=False,))


class _AdaptiveLogSoftmaxWithLoss(nn.AdaptiveLogSoftmaxWithLoss):
    def __call__(self, input):
        t = torch.tensor([0, 1, 4, 8]).to(input.device)
        return nn.AdaptiveLogSoftmaxWithLoss.__call__(self, input, t).output

add_test(NewModuleTest(
    constructor=lambda: _AdaptiveLogSoftmaxWithLoss(16, 10, [2, 6]),
    input_size=(4, 16),
    fullname='AdaptiveLogSoftmax'))


# The following are helpers for TestNN.test_affine_*
if torch.cuda.is_available():
    def device_():
        return ['cpu', 'cuda']
else:
    def device_():
        return ['cpu']


def angle_rad_():
    return [r * math.pi * 2 for r in [0.0, 0.5, 0.25, 0.125, random.random()]]


def axis_vector_():
    t = (random.random(), random.random(), random.random())
    l = sum(x ** 2 for x in t) ** 0.5

    return [(1.0, 0.0, 0.0), (0.0, 1.0, 0.0), (0.0, 0.0, 1.0), tuple(x / l for x in t)]


def input_size2d_():
    return [[1, 1, 3, 5], [1, 1, 3, 3], [1, 1, 4, 4], [1, 1, 3, 4]]


def output_size2d_():
    return [[1, 1, 5, 3], [1, 1, 3, 5], [1, 1, 4, 3], [1, 1, 5, 5], [1, 1, 6, 6]]


def input_size2dsq_():
    return [[1, 1, 2, 2], [1, 1, 3, 3], [1, 1, 4, 4], [1, 1, 6, 6]]


def output_size2dsq_():
    return [[1, 1, 2, 2], [1, 1, 3, 3], [1, 1, 4, 4], [1, 1, 5, 5], [1, 1, 6, 6]]


def input_size3d_():
    return [[1, 1, 2, 2, 2], [1, 1, 2, 3, 4], [1, 1, 3, 3, 3], [1, 1, 4, 4, 4], [1, 1, 3, 4, 5]]


def input_size3dsq_():
    return [[1, 1, 2, 2, 2], [1, 1, 3, 3, 3], [1, 1, 4, 4, 4], [1, 1, 6, 6, 6]]


def output_size3dsq_():
    return [[1, 1, 2, 2, 2], [1, 1, 3, 3, 3], [1, 1, 4, 4, 4], [1, 1, 5, 5, 5], [1, 1, 6, 6, 6]]


def output_size3d_():
    return [[1, 1, 2, 2, 2], [1, 1, 3, 3, 3], [1, 1, 3, 4, 5], [1, 1, 4, 3, 2], [1, 1, 5, 5, 5], [1, 1, 6, 6, 6]]


def _buildEquivalentAffineTransforms2d(device, input_size, output_size, angle_rad):
    input_center = [(x - 1) / 2.0 for x in input_size]
    output_center = [(x - 1) / 2.0 for x in output_size]

    s = math.sin(angle_rad)
    c = math.cos(angle_rad)

    intrans_ary = np.array([
        [1, 0, input_center[2]],
        [0, 1, input_center[3]],
        [0, 0, 1],
    ], dtype=np.float64)

    inscale_ary = np.array([
        [input_center[2], 0, 0],
        [0, input_center[3], 0],
        [0, 0, 1],
    ], dtype=np.float64)

    rotation_ary = np.array([
        [c, -s, 0],
        [s, c, 0],
        [0, 0, 1],
    ], dtype=np.float64)

    outscale_ary = np.array([
        [1.0 / output_center[2], 0, 0],
        [0, 1.0 / output_center[3], 0],
        [0, 0, 1],
    ], dtype=np.float64)

    outtrans_ary = np.array([
        [1, 0, -output_center[2]],
        [0, 1, -output_center[3]],
        [0, 0, 1],
    ], dtype=np.float64)

    reorder_ary = np.array([
        [0, 1, 0],
        [1, 0, 0],
        [0, 0, 1],
    ], dtype=np.float64)

    transform_ary = np.dot(np.dot(np.dot(np.dot(
        intrans_ary,
        inscale_ary),
        rotation_ary.T),
        outscale_ary),
        outtrans_ary)
    grid_ary = np.dot(np.dot(np.dot(reorder_ary, rotation_ary.T), outscale_ary), outtrans_ary)

    transform_tensor = torch.from_numpy((rotation_ary)).to(device, torch.float32)
    transform_tensor = transform_tensor[:2].unsqueeze(0)

    return transform_tensor, transform_ary, grid_ary


def _buildEquivalentAffineTransforms3d(device, input_size, output_size, angle_rad, axis_vector):
    input_center = [(x - 1) / 2.0 for x in input_size]
    output_center = [(x - 1) / 2.0 for x in output_size]

    s = math.sin(angle_rad)
    c = math.cos(angle_rad)
    c1 = 1 - c

    intrans_ary = np.array([
        [1, 0, 0, input_center[2]],
        [0, 1, 0, input_center[3]],
        [0, 0, 1, input_center[4]],
        [0, 0, 0, 1],
    ], dtype=np.float64)

    inscale_ary = np.array([
        [input_center[2], 0, 0, 0],
        [0, input_center[3], 0, 0],
        [0, 0, input_center[4], 0],
        [0, 0, 0, 1],
    ], dtype=np.float64)

    l, m, n = axis_vector
    scipyRotation_ary = np.array([
        [l * l * c1 + c, m * l * c1 - n * s, n * l * c1 + m * s, 0],
        [l * m * c1 + n * s, m * m * c1 + c, n * m * c1 - l * s, 0],
        [l * n * c1 - m * s, m * n * c1 + l * s, n * n * c1 + c, 0],
        [0, 0, 0, 1],
    ], dtype=np.float64)

    z, y, x = axis_vector
    torchRotation_ary = np.array([
        [x * x * c1 + c, y * x * c1 - z * s, z * x * c1 + y * s, 0],
        [x * y * c1 + z * s, y * y * c1 + c, z * y * c1 - x * s, 0],
        [x * z * c1 - y * s, y * z * c1 + x * s, z * z * c1 + c, 0],
        [0, 0, 0, 1],
    ], dtype=np.float64)

    outscale_ary = np.array([
        [1.0 / output_center[2], 0, 0, 0],
        [0, 1.0 / output_center[3], 0, 0],
        [0, 0, 1.0 / output_center[4], 0],
        [0, 0, 0, 1],
    ], dtype=np.float64)

    outtrans_ary = np.array([
        [1, 0, 0, -output_center[2]],
        [0, 1, 0, -output_center[3]],
        [0, 0, 1, -output_center[4]],
        [0, 0, 0, 1],
    ], dtype=np.float64)

    reorder_ary = np.array([
        [0, 0, 1, 0],
        [0, 1, 0, 0],
        [1, 0, 0, 0],
        [0, 0, 0, 1],
    ], dtype=np.float64)

    transform_ary = np.dot(np.dot(np.dot(np.dot(
        intrans_ary,
        inscale_ary),
        np.linalg.inv(scipyRotation_ary)),
        outscale_ary),
        outtrans_ary)
    grid_ary = np.dot(np.dot(np.dot(reorder_ary, np.linalg.inv(scipyRotation_ary)), outscale_ary), outtrans_ary)

    transform_tensor = torch.from_numpy((torchRotation_ary)).to(device, torch.float32)
    transform_tensor = transform_tensor[:3].unsqueeze(0)

    return transform_tensor, transform_ary, grid_ary
# end TestNN.test_affine_* helpers


if __name__ == '__main__':
    run_tests()