from __future__ import division
from builtins import round

import itertools
import numpy as np
import unittest

import torch
import torch.jit
import torch.nn.functional as F
from torch.nn.modules.utils import _single, _pair

from hypothesis import settings, HealthCheck
from hypothesis import assume, given, note
from hypothesis import strategies as st
import torch.testing._internal.hypothesis_utils as hu
hu.assert_deadline_disabled()

from torch.testing._internal.common_utils import TestCase
from torch.testing._internal.common_quantization import skipIfNoFBGEMM
from torch.testing._internal.common_quantized import _quantize, _dequantize, _calculate_dynamic_qparams, \
    override_quantized_engine, supported_qengines, override_qengines

np_dtype = {
    torch.quint8 : np.uint8,
    torch.qint8 : np.int8,
    torch.qint32 : np.int32
}

# Make sure we won't have overflows from vpmaddubsw instruction used in FBGEMM.
# On the current Intel x86 architecture, we need to utilize vpmaddubsw instruction
# for the 8-bit int multiplication. This instruction vertically multiplies each
# unsigned 8-bit integer from a with the corresponding signed 8-bit integer from
# b, producing intermediate signed 16-bit integers. This function modifies the
# weights to eliminate the overflow on the signed 16-bit integers.
def avoid_vpmaddubsw_overflow_linear(
    batch_size, input_channels, output_channels, X, X_min, X_max, W, W_min, W_max
):
    for i, j in np.ndindex((batch_size, output_channels)):
        for k in range(0, input_channels // 2 * 2, 2):
            x0 = X[i, k] - X_min
            x1 = X[i, k + 1] - X_min
            w0 = W[j, k] - 128 - W_min
            w1 = W[j, k + 1] - 128 - W_min
            if x0 * w0 + x1 * w1 < -(1 << 15):
                w1_adjusted = (-(1 << 15) - float(x0) * w0) / x1
                W[j, k + 1] = int(w1_adjusted) + 128 + W_min
            elif x0 * w0 + x1 * w1 > (1 << 15) - 1:
                w1_adjusted = ((1 << 15) - 1 - float(x0) * w0) / x1
                W[j, k + 1] = int(w1_adjusted) + 128 + W_min

    # Go through the same loop again to double check we don't have any overflow
    for i, j in np.ndindex((batch_size, output_channels)):
        for k in range(0, input_channels // 2 * 2, 2):
            x0 = X[i, k] - X_min
            x1 = X[i, k + 1] - X_min
            w0 = W[j, k] - 128 - W_min
            w1 = W[j, k + 1] - 128 - W_min
            assert -(1 << 15) <= x0 * w0 + x1 * w1 < (1 << 15)


# Reference quantized Linear operator
def qlinear_ref(X_q, X_scale, X_zp, W_q, W_scale, W_zp, b_q, Y_scale, Y_zp):
    X_q = np.reshape(X_q, (-1, X_q.shape[X_q.ndim - 1]))
    row_offsets_ref = X_q.sum(axis=1).astype(np.int32).reshape((-1, 1))
    col_offsets_ref = W_q.sum(axis=1).astype(np.int32).reshape((1, -1))
    assert X_q.ndim == 2
    batch_size, input_channels = X_q.shape
    Prod_XqWq_ref = (
        np.matmul(X_q.astype(np.int32), W_q.astype(np.int32).T)
        - W_zp * row_offsets_ref
        - X_zp * col_offsets_ref
        + input_channels * X_zp * W_zp
    )
    if b_q is not None:
        Prod_XqWq_ref += b_q
    Y_q_ref = _quantize(Prod_XqWq_ref, Y_scale / (X_scale * W_scale), Y_zp)
    return Y_q_ref

"""Computes the output shape given pooling parameters."""
def pool_output_shape(input_size, kernel_size, padding, stride,
                      dilation, ceiling_mode=False):
    if stride is None:
        stride = kernel_size
    output_size = (
        (input_size + 2 * padding - dilation * (kernel_size - 1) - 1
         + (stride - 1 if ceiling_mode else 0)) // stride + 1)
    if (padding > 0 and
            ((output_size - 1) * stride >= input_size + padding)):
        output_size += 1
    return output_size

"""
Util for creating a random tensor and quantization params when Hypothesis
is undesirable.
"""
def _get_random_tensor_and_q_params(shapes, rand_scale, torch_type):
    X = (torch.rand(*shapes, dtype=torch.float) - 0.5) * rand_scale
    # Calculate reasonable quantization params
    min_val = torch.min(X)
    max_val = torch.max(X)
    if torch_type == torch.qint32:
        X_zero_point = int(torch.randint(-1 * (2 ** 31), 2 ** 31 - 1, (1,)))
        num_bins = 2 ** 32
        X_scale = float(max_val - min_val) / num_bins
    elif torch_type == torch.qint8:
        X_zero_point = int(torch.randint(-128, 127, (1,)))
        num_bins = 2 ** 8
        X_scale = float(max_val - min_val) / num_bins
    else:  # torch.quint8
        X_zero_point = 127
        num_bins = 2 ** 8
        X_scale = float(max_val - min_val) / num_bins
    if X_scale == 0:
        X_scale = 1e-10
    return X, X_scale, X_zero_point


class TestQuantizedOps(TestCase):

    """Tests the correctness of the quantized::relu op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams()))
    def test_qrelu(self, X):
        X, (scale, zero_point, torch_type) = X

        Y = X.copy()
        Y[Y < 0] = 0
        qY = torch.quantize_per_tensor(torch.from_numpy(Y), scale=scale,
                                       zero_point=zero_point, dtype=torch_type)
        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)

        ops_under_test = {
            'native': torch.relu,
            'nn.functional': torch.nn.functional.relu,
        }

        for name, op in ops_under_test.items():
            qY_hat = op(qX)
            self.assertEqual(qY, qY_hat, msg="{} relu failed".format(name))

        ops_under_test_inplace = {
            'inplace native': torch.relu_,
            'inplace nn.functional': torch.nn.functional.relu_,
        }

        for name, op_ in ops_under_test_inplace.items():
            qY_hat = qX.clone()
            op_(qY_hat)
            self.assertEqual(qY, qY_hat, msg="{} relu failed".format(name))

    """Tests the correctness of the quantized::relu op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams()))
    def test_qrelu6(self, X):
        X, (scale, zero_point, torch_type) = X

        Y = X.copy()
        Y[Y < 0] = 0
        Y[Y > 6.0] = 6.0
        qY = torch.quantize_per_tensor(torch.from_numpy(Y), scale=scale,
                                       zero_point=zero_point, dtype=torch_type)
        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)

        ops_under_test = {
            'ops.quantized': torch.ops.quantized.relu6,
            'module': torch.nn.quantized.ReLU6(),
        }

        for name, op in ops_under_test.items():
            for inplace in (True, False):
                if hasattr(op, 'inplace'):
                    op.inplace = inplace
                    qY_hat = op(qX)
                else:
                    qY_hat = op(qX, inplace=inplace)
                self.assertEqual(qY, qY_hat,
                                 msg="{} relu failed".format(name))

    """Tests the correctness of the quantized::relu op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams()),
           alpha=st.floats(0.0, 1.0, allow_nan=False, allow_infinity=False))
    def test_qrelu_leaky(self, X, alpha):
        X, (scale, zero_point, torch_type) = X

        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)
        dqX = qX.dequantize()

        # torch.nn.functional
        op = torch.nn.functional.leaky_relu
        dqY = op(dqX, negative_slope=alpha)
        qY = torch.quantize_per_tensor(dqY, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)
        qY_hat = op(qX, negative_slope=alpha)
        self.assertEqual(qY.dequantize(), qY_hat.dequantize(),
                         msg="F.leaky_relu failed ({} vs {})".format(qY, qY_hat))

    """Tests the correctness of the quantized::elu op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       elements=hu.floats(-1e3, 1e3, allow_nan=False, allow_infinity=False),
                       qparams=hu.qparams()),
           alpha=st.floats(0.01, 10.0, allow_nan=False, allow_infinity=False))
    def test_qelu(self, X, alpha):
        X, (scale, zero_point, torch_type) = X

        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)
        op = torch.nn.quantized.functional.elu

        # calculate ELU(dqX) and quantize
        dqX = qX.dequantize()
        dqY_hat = dqX.clone()
        dqY_hat[dqX < 0] = alpha * (torch.exp(dqY_hat[dqX < 0]) - 1.)
        qY_hat = torch.quantize_per_tensor(dqY_hat, scale=scale, zero_point=zero_point,
                                           dtype=torch_type)

        # test regular
        qY = op(qX, alpha=alpha)
        self.assertEqual(qY, qY_hat,
                         msg="F.elu failed ({} vs {})".format(qY, qY_hat))

        # test inplace
        qXcopy = qX.clone()
        op(qXcopy, alpha=alpha, inplace=True)
        self.assertEqual(qXcopy, qY_hat,
                         msg="F.elu_ failed ({} vs {})".format(qXcopy, qY_hat))

        # test explicit scale and zp
        qYout = op(qX, alpha=alpha, scale=scale, zero_point=zero_point)
        self.assertEqual(qYout, qY_hat,
                         msg="F.elu.out failed ({} vs {})".format(qY, qY_hat))

    """Tests the correctness of the quantized::qnnpack_sigmoid op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams()))
    def test_qsigmoid(self, X):
        # Note: QNNPACK is tested separately in TestQNNPackOps
        X, (scale, zero_point, torch_type) = X

        X = torch.from_numpy(X)
        Y = torch.sigmoid(X)

        qX = torch.quantize_per_tensor(X, scale=scale,
                                       zero_point=zero_point,
                                       dtype=torch_type)

        # Quantize the reference to account for max error.
        # Note that the output scale has +1, because we use scale of 1.0/2^BITS
        # in the implementations.
        f_min, f_max = 0.0, 1.0
        q_min, q_max = torch.iinfo(torch_type).min, torch.iinfo(torch_type).max
        output_scale = (f_max - f_min) / (q_max - q_min + 1.0)
        output_zero_point = output_zero_point = 0 if torch_type == torch.qint32 else q_min
        qY = torch.quantize_per_tensor(Y, scale=output_scale,
                                       zero_point=output_zero_point,
                                       dtype=torch_type)
        qY_hat = torch.sigmoid(qX)
        self.assertEqual(qY, qY_hat,
                         msg="Sigmoid failed: {} vs. {}".format(qY, qY_hat))

    """Tests the correctness of the quantized::qhardsigmoid op."""
    @override_qengines
    def test_qhardsigmoid(self):
        max_sides = (3, 5)
        side_lens = (1, 7, 8)
        torch_types = (torch.quint8, torch.qint8)
        combined = [max_sides, side_lens, torch_types]
        test_cases = itertools.product(*combined)
        for test_case in test_cases:
            max_side, side_len, torch_type = test_case

            if torch.backends.quantized.engine == 'qnnpack' and torch_type != torch.quint8:
                continue

            shapes = [side_len] * max_side
            X, X_scale, X_zero_point = \
                _get_random_tensor_and_q_params(shapes, 2.0, torch_type)
            qX = torch.quantize_per_tensor(X, scale=X_scale,
                                           zero_point=X_zero_point,
                                           dtype=torch_type)
            dqX = qX.dequantize()


            # Quantize the reference to account for max error.
            # Note that the output scale has +1, because we use scale of 1.0/2^BITS
            # in the implementations.
            f_min, f_max = 0.0, 1.0
            q_min, q_max = torch.iinfo(torch_type).min, torch.iinfo(torch_type).max
            output_scale = (f_max - f_min) / (q_max - q_min + 1.0)
            output_zero_point = 0 if torch_type == torch.qint32 else q_min
            dqY_hat = F.hardsigmoid(dqX)
            qY_hat = torch.quantize_per_tensor(dqY_hat, scale=output_scale,
                                               zero_point=output_zero_point,
                                               dtype=torch_type)

            qY = torch.nn.quantized.functional.hardsigmoid(qX)
            self.assertEqual(qY, qY_hat,
                             msg="Hardsigmoid failed: {} vs. {}, {}".format(qY, qY_hat, torch.backends.quantized.engine))


    """Tests the correctness of the quantized::qlayer_norm op."""
    @skipIfNoFBGEMM
    def test_qlayer_norm(self):
        # hypothesis is flaky for this test, create test cases manually
        max_sides = (4, 5)
        side_lens = (1, 8, 11)
        torch_types = (torch.qint8, torch.quint8)
        y_scales = (0.1, 4.23)
        y_zero_points = (0, 1)
        combined = [max_sides, side_lens, torch_types, y_scales, y_zero_points]
        test_cases = itertools.product(*combined)

        with override_quantized_engine("fbgemm"):
            for test_case in test_cases:

                max_side, side_len, torch_type, Y_scale, Y_zero_point = test_case
                shapes = [side_len] * max_side

                # In the FP kernel, mean and variance are calculated in floating point.
                # In the quantized kernel, they are calculated in integer arithmetic.
                # Because of this, the numerics do not always match exactly which is
                # expected and acceptable. We do two things to whitelist this failure
                # in this test:
                # 1. do not use Hypothesis to generate the input tensor.  Hypothesis
                #    favors homogeneous inputs in its search strategies which isn't
                #    representative of the inputs we care about, and tends to maximize
                #    this particular numerics difference.
                # 2. whitelist a small % of off by Y_scale errors.  Even when the
                #    variance of the input is high, there can be off by one errors
                #    in the result if the input value happens to fall exactly on
                #    the bin boundary of the output scale.
                #
                # If we want the numerics to match we could switch to calculating
                # mean+var in floating point in the future, at the cost of speed.
                X, X_scale, X_zero_point = \
                    _get_random_tensor_and_q_params(shapes, 1.0, torch_type)

                qX = torch.quantize_per_tensor(X, scale=X_scale,
                                               zero_point=X_zero_point,
                                               dtype=torch_type)
                dqX = qX.dequantize()

                # Enforce non-homogeneous inputs
                enough_unique_vals_in_each_layer = sum(
                    1 if (
                        dqX[i].shape[0] < 5 or
                        float(torch.unique(dqX[i]).shape[0]) / dqX[i].shape[0] > 0.01
                    ) else 0
                    for i in range(dqX.shape[0])
                ) == dqX.shape[0]
                assume(enough_unique_vals_in_each_layer)

                # Initialize the weights non-randomly for reproducibility, to avoid
                # flaky tests
                weight = torch.ones(*qX.size()[1:], dtype=torch.float) * 0.5
                bias = torch.ones(*qX.size()[1:], dtype=torch.float) * 1
                epsilon = 1e-5

                qY = torch.ops.quantized.layer_norm(
                    qX, qX.size()[1:], weight=weight, bias=bias, eps=epsilon,
                    output_scale=Y_scale, output_zero_point=Y_zero_point)

                Y_hat = F.layer_norm(
                    dqX, dqX.size()[1:], weight=weight, bias=bias, eps=epsilon)
                qY_hat = torch.quantize_per_tensor(
                    Y_hat, scale=Y_scale, zero_point=Y_zero_point, dtype=torch_type)

                # Due to the numerics difference mentioned above between calculating
                # the variance in float vs int, the results can still be slightly
                # different.
                dqY = qY.dequantize()
                dqY_hat = qY_hat.dequantize()
                diff = dqY - dqY_hat

                # off-by-one errors are magnitude of Y_scale
                num_diff = torch.sum(diff > Y_scale * 1.0001)
                pct_diff = float(num_diff) / (diff.numel() + 1e-5)
                num_diff_off_by_one = torch.sum((diff > 0) * (diff <= Y_scale))
                pct_diff_off_by_one = float(num_diff_off_by_one) / (diff.numel() + 1e-5)

                self.assertTrue(pct_diff < 1e-6)
                self.assertTrue(pct_diff_off_by_one < 0.01)


    """Tests the correctness of the quantized::qnnpack_tanh op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams()))
    def test_qtanh(self, X):
        # Note: QNNPACK is tested separately in TestQNNPackOps
        X, (scale, zero_point, torch_type) = X

        X = torch.from_numpy(X)
        Y = torch.tanh(X)

        qX = torch.quantize_per_tensor(X, scale=scale,
                                       zero_point=zero_point,
                                       dtype=torch_type)

        # Quantize the reference to account for max error.
        # Note that the output scale has +1, because we use scale of 2.0/2^BITS
        # in the implementations.
        f_min, f_max = -1.0, 1.0
        q_min, q_max = torch.iinfo(torch_type).min, torch.iinfo(torch_type).max
        output_scale = (f_max - f_min) / (q_max - q_min + 1.0)
        output_zero_point = int(round((q_max + q_min) / 2.0))
        qY = torch.quantize_per_tensor(Y, scale=output_scale,
                                       zero_point=output_zero_point,
                                       dtype=torch_type)
        qY_hat = torch.tanh(qX)
        self.assertEqual(qY, qY_hat,
                         msg="TanH failed: {} vs. {}".format(qY, qY_hat))

    """Tests the correctness of the quantized::clamp op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 8, 1, 8, max_numel=10**5),
                       elements=hu.floats(-1e6, 1e6, allow_nan=False),
                       qparams=hu.qparams()),
           min_val=hu.floats(-1e6, 1e6, allow_nan=False),
           max_val=hu.floats(-1e6, 1e6, allow_nan=False))
    def test_qclamp(self, X, min_val, max_val):
        X, (scale, zero_point, torch_type) = X

        assume(min_val <= max_val)
        Y = X.copy()
        Y[Y < min_val] = min_val
        Y[Y > max_val] = max_val
        qY = torch.quantize_per_tensor(torch.from_numpy(Y), scale=scale,
                                       zero_point=zero_point, dtype=torch_type)
        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)

        ops_under_test = {
            'ops.quantized': torch.ops.quantized.clamp,
        }

        for name, op in ops_under_test.items():
            qY_hat = op(qX, min_val, max_val)
            self.assertEqual(qY, qY_hat, msg="{} qclamp failed".format(name))

    """Tests the correctness of the quantized::hardtanh op."""
    @skipIfNoFBGEMM
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 8, 1, 8, max_numel=10**5),
                       elements=hu.floats(-1e6, 1e6, allow_nan=False, allow_infinity=False),
                       qparams=hu.qparams()),
           min_val=hu.floats(-1e6, 1e6, allow_nan=False, allow_infinity=False),
           max_val=hu.floats(-1e6, 1e6, allow_nan=False, allow_infinity=False))
    def test_hardtanh(self, X, min_val, max_val):
        with override_quantized_engine('fbgemm'):
            X, (scale, zero_point, torch_type) = X

            assume(min_val <= max_val)
            Y = X.copy()
            Y[Y < min_val] = min_val
            Y[Y > max_val] = max_val
            qY = torch.quantize_per_tensor(torch.from_numpy(Y), scale=scale,
                                           zero_point=zero_point, dtype=torch_type)
            X = torch.from_numpy(X)
            qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                           dtype=torch_type)

            ops_under_test = {
                'nn.quantized.functional.hardtanh':
                    torch.nn.quantized.functional.hardtanh,
            }

            for name, op in ops_under_test.items():
                qY_hat = op(qX, min_val, max_val)
                self.assertEqual(qY, qY_hat, msg="{} hardtanh failed".format(name))

            ops_under_test_inplace = {
                'inplace nn.quantized.functional.hardtanh':
                    torch.nn.quantized.functional.hardtanh,
            }

            for name, op_ in ops_under_test_inplace.items():
                qY_hat = qX.clone()
                op_(qY_hat, min_val, max_val, inplace=True)
                self.assertEqual(qY, qY_hat, msg="{} hardtanh failed".format(name))

    """Tests the correctness of the quantized::hardswish op."""
    @override_qengines
    def test_hardswish(self):
        max_sides = (3, 5)
        side_lens = (1, 7, 8)
        torch_types = (torch.quint8, torch.qint8)
        y_scales = (0.1, 4.23)
        y_zero_points = (0, 1)
        combined = [max_sides, side_lens, torch_types, y_scales, y_zero_points]
        test_cases = itertools.product(*combined)
        for test_case in test_cases:
            max_side, side_len, torch_type, Y_scale, Y_zero_point = test_case

            if torch.backends.quantized.engine == 'qnnpack' and torch_type != torch.quint8:
                continue

            shapes = [side_len] * max_side
            X, X_scale, X_zero_point = \
                _get_random_tensor_and_q_params(shapes, 2.0, torch_type)
            qX = torch.quantize_per_tensor(X, scale=X_scale, zero_point=X_zero_point,
                                           dtype=torch_type)
            dqX = qX.dequantize()

            dqY_hat = F.hardswish(dqX)
            qY_hat = torch.quantize_per_tensor(dqY_hat, scale=Y_scale,
                                               zero_point=Y_zero_point,
                                               dtype=torch_type)

            qY = torch.nn.quantized.functional.hardswish(
                qX, scale=Y_scale, zero_point=Y_zero_point)
            self.assertEqual(
                qY, qY_hat,
                msg="Hardswish failed: {} vs {}, {}".format(qY, qY_hat, torch.backends.quantized.engine))

    """Tests the correctness of the scalar addition."""
    @unittest.skip("Failing on MacOS")
    @given(A=hu.tensor(shapes=hu.array_shapes(1, 4, 1, 5),
                       elements=hu.floats(-1e6, 1e6, allow_nan=False),
                       qparams=hu.qparams()),
           b=hu.floats(-1e6, 1e6, allow_nan=False, allow_infinity=False))
    def test_qadd_scalar_relu(self, A, b):
        import copy
        add_scalar = torch.ops.quantized.add_scalar
        add_scalar_relu = torch.ops.quantized.add_scalar_relu

        A, (scale, zero_point, dtype) = A
        A = A.astype(np.float32)
        qA = torch.quantize_per_tensor(torch.from_numpy(A), scale, zero_point, dtype)

        C = qA.dequantize() + round(b / scale) * scale
        C_relu = copy.deepcopy(C)
        C_relu[C_relu < 0] = 0

        C_hat = add_scalar(qA, b)
        C_ref = torch.quantize_per_tensor(C, C_hat.q_scale(), C_hat.q_zero_point(), dtype)
        C_relu_hat = add_scalar_relu(qA, b)
        C_relu_ref = torch.quantize_per_tensor(
            C_relu, C_relu_hat.q_scale(), C_relu_hat.q_zero_point(), dtype)

        self.assertEqual(C_ref.dequantize(), C_hat.dequantize(),
                         msg="Scalar add results don't match:\
                         {} vs {}".format(C_ref.dequantize(), C_hat.dequantize()))
        self.assertEqual(C_relu_ref.dequantize(), C_relu_hat.dequantize(),
                         msg="Scalar add relu results don't match:\
                         {} vs {}".format(C_relu_ref.dequantize(), C_relu_hat.dequantize()))

    """Tests the correctness of the add and add_relu op."""
    def test_qadd_relu_same_qparams(self):
        for dtype in [torch.quint8, torch.qint8, torch.qint32]:
            add_relu = torch.ops.quantized.add_relu
            add = torch.ops.quantized.add
            add_out = torch.ops.quantized.add_out
            add_relu_out = torch.ops.quantized.add_relu_out

            # NB: This is a strange size so that we exercise both the vectorized
            # implementation (64-element chunks at at time) as well as the scalar
            # implementation
            A = torch.arange(-128, 130, dtype=torch.float)
            B = torch.arange(-128, 130, dtype=torch.float)
            scale = 2.0
            zero_point = 127
            qA = torch.quantize_per_tensor(A, scale=scale, zero_point=zero_point,
                                           dtype=dtype)
            qB = torch.quantize_per_tensor(B, scale=scale, zero_point=zero_point,
                                           dtype=dtype)

            # Add ReLU ground truth
            C = (qA.dequantize() + qB.dequantize()).numpy()
            qC = _quantize(C, scale, zero_point, dtype=np_dtype[dtype])
            qC_hat = add(qA, qB, scale=scale, zero_point=zero_point)
            np.testing.assert_equal(qC, qC_hat.int_repr(),
                                    "Quantized addition failed.")
            qC_out_hat = torch._empty_affine_quantized(qC.shape,
                                                       scale=scale,
                                                       zero_point=zero_point,
                                                       dtype=dtype)
            add_out(qA, qB, out=qC_out_hat)
            self.assertEqual(qC_hat, qC_out_hat, msg="Add.out failed")

            # Add + ReLU ground truth
            Crelu = C.copy()
            Crelu[C < 0] = 0
            qCrelu = _quantize(Crelu, scale, zero_point, dtype=np_dtype[dtype])
            qCrelu_hat = add_relu(qA, qB, scale=scale, zero_point=zero_point)
            np.testing.assert_equal(qCrelu, qCrelu_hat.int_repr(),
                                    "Quantized addition with ReLU failed.")
            qCrelu_out_hat = torch._empty_affine_quantized(qCrelu.shape,
                                                           scale=scale,
                                                           zero_point=zero_point,
                                                           dtype=dtype)
            add_relu_out(qA, qB, out=qCrelu_out_hat)
            self.assertEqual(qCrelu_hat, qCrelu_out_hat,
                             msg="AddReLU.out failed")


    """Tests the correctness of the add and add_relu op."""
    def test_qadd_relu_different_qparams(self):
        for dtype in [torch.quint8, torch.qint8, torch.qint32]:
            add_relu = torch.ops.quantized.add_relu
            add = torch.ops.quantized.add
            add_out = torch.ops.quantized.add_out
            add_relu_out = torch.ops.quantized.add_relu_out

            # NB: This is a strange size so that we exercise both the vectorized
            # implementation (64-element chunks at at time) as well as the scalar
            # implementation
            A = torch.arange(-128, 130, dtype=torch.float)
            B = torch.arange(-128, 130, dtype=torch.float)
            scale_A = 3.0
            zero_point_A = 7
            scale_B = 5.0
            zero_point_B = 127

            scale_C = 0.5
            zero_point_C = 5

            qA = torch.quantize_per_tensor(A, scale=scale_A, zero_point=zero_point_A,
                                           dtype=dtype)
            qB = torch.quantize_per_tensor(B, scale=scale_B, zero_point=zero_point_B,
                                           dtype=dtype)

            # Add ground truth
            C = (qA.dequantize() + qB.dequantize()).numpy()
            qC = _quantize(C, scale_C, zero_point_C, dtype=np_dtype[dtype])
            qC_hat = add(qA, qB, scale=scale_C, zero_point=zero_point_C)
            np.testing.assert_equal(qC, qC_hat.int_repr(),
                                    "Quantized addition failed.")
            qC_out_hat = torch._empty_affine_quantized(qC.shape,
                                                       scale=scale_C,
                                                       zero_point=zero_point_C,
                                                       dtype=dtype)
            add_out(qA, qB, out=qC_out_hat)
            self.assertEqual(qC_hat, qC_out_hat, msg="Add.out failed")

            # Add + ReLU ground truth
            Crelu = C.copy()
            Crelu[C < 0] = 0
            qCrelu = _quantize(Crelu, scale_C, zero_point_C, dtype=np_dtype[dtype])
            qCrelu_hat = add_relu(qA, qB, scale=scale_C, zero_point=zero_point_C)
            np.testing.assert_equal(qCrelu, qCrelu_hat.int_repr(),
                                    "Quantized addition with ReLU failed.")
            qCrelu_out_hat = torch._empty_affine_quantized(qCrelu.shape,
                                                           scale=scale_C,
                                                           zero_point=zero_point_C,
                                                           dtype=dtype)
            add_relu_out(qA, qB, out=qCrelu_out_hat)
            self.assertEqual(qCrelu_hat, qCrelu_out_hat,
                             msg="AddReLU.out failed")

    """Tests the correctness of the mul and mul_relu op."""
    def test_qmul_relu_same_qparams(self):
        for dtype in [torch.quint8, torch.qint8, torch.qint32]:
            mul_relu = torch.ops.quantized.mul_relu
            mul = torch.ops.quantized.mul
            mul_out = torch.ops.quantized.mul_out
            mul_relu_out = torch.ops.quantized.mul_relu_out

            A = torch.arange(-100, 100, dtype=torch.float)
            B = torch.arange(-100, 100, dtype=torch.float)
            scale = 2.0
            zero_point = 127
            qA = torch.quantize_per_tensor(A, scale=scale, zero_point=zero_point,
                                           dtype=dtype)
            qB = torch.quantize_per_tensor(B, scale=scale, zero_point=zero_point,
                                           dtype=dtype)

            # mul ReLU ground truth
            C = (qA.dequantize() * qB.dequantize()).numpy()
            qC = _quantize(C, scale, zero_point, dtype=np_dtype[dtype])
            qC_hat = mul(qA, qB, scale=scale, zero_point=zero_point)
            np.testing.assert_equal(qC, qC_hat.int_repr(),
                                    "Quantized mulition failed.")
            qC_out_hat = torch._empty_affine_quantized(qC.shape,
                                                       scale=scale,
                                                       zero_point=zero_point,
                                                       dtype=dtype)
            mul_out(qA, qB, out=qC_out_hat)
            self.assertEqual(qC_hat, qC_out_hat, msg="mul.out failed")

            # mul + ReLU ground truth
            Crelu = C.copy()
            Crelu[C < 0] = 0
            qCrelu = _quantize(Crelu, scale, zero_point, dtype=np_dtype[dtype])
            qCrelu_hat = mul_relu(qA, qB, scale=scale, zero_point=zero_point)
            np.testing.assert_equal(qCrelu, qCrelu_hat.int_repr(),
                                    "Quantized mulition with ReLU failed.")
            qCrelu_out_hat = torch._empty_affine_quantized(qCrelu.shape,
                                                           scale=scale,
                                                           zero_point=zero_point,
                                                           dtype=dtype)
            mul_relu_out(qA, qB, out=qCrelu_out_hat)
            self.assertEqual(qCrelu_hat, qCrelu_out_hat,
                             msg="mulReLU.out failed")

            # Scalar multiplication
            for b in B:
                C_ref = qA.dequantize().numpy() * b.item()
                qC_hat = torch.ops.quantized.mul_scalar(qA, b.item())

                self.assertEqual(C_ref, qC_hat.dequantize())

            # Scalar multiplication + relu
            for b in B:
                C_ref = qA.dequantize().numpy() * b.item()
                C_ref[C_ref < 0] = 0
                qC_hat = torch.ops.quantized.mul_scalar_relu(qA, b.item())

                self.assertEqual(C_ref, qC_hat.dequantize())

    """Tests the correctness of the mul and mul_relu op."""
    def test_qmul_relu_different_qparams(self):
        for dtype in [torch.quint8, torch.qint8, torch.qint32]:
            mul_relu = torch.ops.quantized.mul_relu
            mul = torch.ops.quantized.mul
            mul_out = torch.ops.quantized.mul_out
            mul_relu_out = torch.ops.quantized.mul_relu_out

            A = torch.arange(-100, 100, dtype=torch.float)
            B = torch.arange(-100, 100, dtype=torch.float)
            scale_A = 3.0
            zero_point_A = 7
            scale_B = 5.0
            zero_point_B = 127

            scale_C = 0.5
            zero_point_C = 5

            qA = torch.quantize_per_tensor(A, scale=scale_A, zero_point=zero_point_A,
                                           dtype=dtype)
            qB = torch.quantize_per_tensor(B, scale=scale_B, zero_point=zero_point_B,
                                           dtype=dtype)

            # mul ground truth
            C = (qA.dequantize() * qB.dequantize()).numpy()
            qC = _quantize(C, scale_C, zero_point_C, dtype=np_dtype[dtype])
            qC_hat = mul(qA, qB, scale=scale_C, zero_point=zero_point_C)
            np.testing.assert_equal(qC, qC_hat.int_repr(),
                                    "Quantized multiplication failed.")
            qC_out_hat = torch._empty_affine_quantized(qC.shape,
                                                       scale=scale_C,
                                                       zero_point=zero_point_C,
                                                       dtype=dtype)
            mul_out(qA, qB, out=qC_out_hat)
            self.assertEqual(qC_hat, qC_out_hat, msg="mul.out failed")

            # mul + ReLU ground truth
            Crelu = C.copy()
            Crelu[C < 0] = 0
            qCrelu = _quantize(Crelu, scale_C, zero_point_C, dtype=np_dtype[dtype])
            qCrelu_hat = mul_relu(qA, qB, scale=scale_C, zero_point=zero_point_C)
            np.testing.assert_equal(qCrelu, qCrelu_hat.int_repr(),
                                    "Quantized multiplication with ReLU failed.")
            qCrelu_out_hat = torch._empty_affine_quantized(qCrelu.shape,
                                                           scale=scale_C,
                                                           zero_point=zero_point_C,
                                                           dtype=dtype)
            mul_relu_out(qA, qB, out=qCrelu_out_hat)
            self.assertEqual(qCrelu_hat, qCrelu_out_hat,
                             msg="mulReLU.out failed")

    """Tests the correctness of the mul and mul_relu op."""
    def test_qmul_broadcast(self):
        mul_relu = torch.ops.quantized.mul_relu
        mul = torch.ops.quantized.mul
        mul_out = torch.ops.quantized.mul_out
        mul_relu_out = torch.ops.quantized.mul_relu_out

        # A = torch.arange(-25, 25, dtype=torch.float)
        # B = torch.arange(-25, 25, dtype=torch.float)
        A = torch.randn(8, 1, 6, 1)
        B = torch.randn(7, 1, 5)
        scale_A = 3.0
        zero_point_A = 7
        scale_B = 5.0
        zero_point_B = 127

        scale_C = 0.5
        zero_point_C = 5

        qA = torch.quantize_per_tensor(A, scale=scale_A, zero_point=zero_point_A,
                                       dtype=torch.quint8)
        qB = torch.quantize_per_tensor(B, scale=scale_B, zero_point=zero_point_B,
                                       dtype=torch.quint8)

        # mul ground truth
        C = (qA.dequantize() * qB.dequantize()).numpy()
        qC = _quantize(C, scale_C, zero_point_C)
        qC_hat = mul(qA, qB, scale=scale_C, zero_point=zero_point_C)
        np.testing.assert_equal(qC, qC_hat.int_repr(),
                                "Quantized multiplication failed.")

    """Tests channel shuffle operation on quantized tensors."""
    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=2, max_side=32, max_numel=10**5),
                       qparams=hu.qparams(dtypes=[torch.quint8])),
           groups=st.integers(2, 6))
    def test_channel_shuffle(self, X, groups):
        X, (scale, zero_point, torch_type) = X
        channels = X.shape[-3]
        iH, iW = X.shape[-2:]
        assume(channels % groups == 0)

        a = torch.from_numpy(X)
        a = torch.rand(a.shape)
        a_out = torch.nn.functional.channel_shuffle(a, groups)

        a_ref = torch.quantize_per_tensor(a_out, scale=scale,
                                          zero_point=zero_point, dtype=torch_type)
        a_ref = a_ref.dequantize()
        qa = torch.quantize_per_tensor(a, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)

        a_hat = torch.nn.functional.channel_shuffle(qa, groups)
        self.assertEqual(a_ref, a_hat.dequantize(),
                         msg="torch.nn.functional.channel_shuffle results are off")

    """Tests max pool operation on quantized tensors."""
    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=3, max_dims=4,
                                              min_side=1, max_side=10),
                       qparams=hu.qparams()),
           kernel=st.sampled_from((3, 5, 7)),
           stride=st.sampled_from((None, 1, 2)),
           dilation=st.integers(1, 2),
           padding=st.integers(0, 2),
           ceil_mode=st.booleans())
    def test_max_pool2d(self, X, kernel, stride, dilation, padding, ceil_mode):
        X, (scale, zero_point, torch_type) = X
        # Check constraints
        assume(kernel // 2 >= padding)  # Kernel cannot be overhanging!
        iH, iW = X.shape[-2:]
        oH = pool_output_shape(iH, kernel, padding, stride, dilation, ceil_mode)
        assume(oH > 0)
        oW = pool_output_shape(iW, kernel, padding, stride, dilation, ceil_mode)
        assume(oW > 0)

        a = torch.from_numpy(X)
        a_pool = torch.nn.functional.max_pool2d(a, kernel_size=kernel,
                                                stride=stride,
                                                padding=padding, dilation=dilation,
                                                ceil_mode=ceil_mode)
        a_ref = torch.quantize_per_tensor(a_pool, scale=scale,
                                          zero_point=zero_point, dtype=torch_type)
        a_ref = a_ref.dequantize()
        qa = torch.quantize_per_tensor(a, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)

        ops_under_test = {
            "torch": torch.max_pool2d,
            "nn.functional": torch.nn.functional.max_pool2d,
            "nn.quantized.functional": torch.nn.quantized.functional.max_pool2d
        }

        for name, op in ops_under_test.items():
            a_hat = op(qa, kernel_size=kernel, stride=stride, padding=padding,
                       dilation=dilation, ceil_mode=ceil_mode)
            self.assertEqual(a_ref, a_hat.dequantize(),
                             msg="{} results are off".format(name))
        # Test the ops.quantized separately, because None is not treated.
        a_hat = torch.ops.quantized.max_pool2d(
            qa, kernel_size=_pair(kernel),
            stride=_pair(kernel if stride is None else stride),
            padding=_pair(padding), dilation=_pair(dilation), ceil_mode=ceil_mode)
        self.assertEqual(a_ref, a_hat.dequantize(),
                         msg="ops.quantized.max_pool2d results are off")

    """Tests max pool operation on NHWC quantized tensors."""
    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=1, max_side=10),
                       qparams=hu.qparams()),
           kernel=st.sampled_from((3, 5, 7)),
           stride=st.sampled_from((None, 1, 2)),
           dilation=st.integers(1, 2),
           padding=st.integers(0, 2),
           ceil_mode=st.booleans())
    def test_max_pool2d_nhwc(self, X, kernel, stride, dilation, padding, ceil_mode):
        X, (scale, zero_point, torch_type) = X
        # Ensure we hit the vectorized paths
        # 176 = 128 + 32 + 16
        # 128 hits the interleaved path
        # 32 hits the non-interleaved path
        # 16 hits the scalar path
        if X.shape[1] < 176:
            X = np.repeat(X, 176 / X.shape[1], 1)
        # Check constraints
        assume(kernel // 2 >= padding)  # Kernel cannot be overhanging!
        iH, iW = X.shape[-2:]
        oH = pool_output_shape(iH, kernel, padding, stride, dilation, ceil_mode)
        assume(oH > 0)
        oW = pool_output_shape(iW, kernel, padding, stride, dilation, ceil_mode)
        assume(oW > 0)

        X_nchw = np.ascontiguousarray(X.transpose([0, 2, 3, 1]))
        a = torch.from_numpy(X_nchw).permute([0, 3, 1, 2])
        a_pool = torch.nn.functional.max_pool2d(a, kernel_size=kernel,
                                                stride=stride,
                                                padding=padding, dilation=dilation,
                                                ceil_mode=ceil_mode)
        a_ref = torch.quantize_per_tensor(a_pool, scale=scale,
                                          zero_point=zero_point, dtype=torch_type)
        a_ref = a_ref.dequantize()
        qa = torch.quantize_per_tensor(torch.from_numpy(X_nchw), scale=scale, zero_point=zero_point,
                                       dtype=torch_type).permute([0, 3, 1, 2])
        self.assertTrue(qa.stride() != sorted(qa.stride()))

        ops_under_test = {
            "torch": torch.max_pool2d,
            "nn.functional": torch.nn.functional.max_pool2d,
            "nn.quantized.functional": torch.nn.quantized.functional.max_pool2d
        }

        for name, op in ops_under_test.items():
            a_hat = op(qa, kernel_size=kernel, stride=stride, padding=padding,
                       dilation=dilation, ceil_mode=ceil_mode)
            self.assertTrue(a_hat.stride() != sorted(a_hat.stride()))
            self.assertEqual(a_ref, a_hat.dequantize(),
                             msg="{} results are off".format(name))
        # Test the ops.quantized separately, because None is not treated.
        a_hat = torch.ops.quantized.max_pool2d(
            qa, kernel_size=_pair(kernel),
            stride=_pair(kernel if stride is None else stride),
            padding=_pair(padding), dilation=_pair(dilation), ceil_mode=ceil_mode)
        self.assertEqual(a_ref, a_hat.dequantize(),
                         msg="ops.quantized.max_pool2d results are off")

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=3, max_dims=4,
                                              min_side=5, max_side=10),
                       qparams=hu.qparams(dtypes=torch.quint8)),
           kernel=st.sampled_from((3, 5)),
           stride=st.sampled_from((None, 1, 2)),
           padding=st.integers(0, 2),
           ceil_mode=st.sampled_from((True, False)),
           count_include_pad=st.sampled_from((True, False)),
           divisor_override=st.sampled_from((None, None)))
    def test_avg_pool2d(self, X, kernel, stride, padding, ceil_mode, count_include_pad, divisor_override):
        """
        Note: we currently cannot test the divisor_override, because quantized op will clamp the result
        within range. However, the float op will not.
        """
        X, (scale, zero_point, torch_type) = X

        assume(kernel // 2 >= padding)  # Kernel cannot be overhanging!
        iH, iW = X.shape[-2:]
        oH = pool_output_shape(iH, kernel, padding, stride, dilation=1)
        assume(oH > 0)
        oW = pool_output_shape(iW, kernel, padding, stride, dilation=1)
        assume(oW > 0)
        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)
        X = qX.dequantize()
        # Run reference on float tensor and then quantize the result for comparison
        X_ref = torch.nn.functional.avg_pool2d(
            X, kernel_size=kernel, stride=stride, padding=padding,
            ceil_mode=ceil_mode, count_include_pad=count_include_pad, divisor_override=divisor_override)
        ops_under_test = {
            "nn.functional": torch.nn.functional.avg_pool2d,
            "nn.quantized.functional": torch.nn.quantized.functional.avg_pool2d
        }
        error_message = r"Results are off for {}:\n\tExpected:\n{}\n\tGot:\n{}"
        for name, op in ops_under_test.items():
            qX_hat = op(qX, kernel_size=kernel, stride=stride, padding=padding, ceil_mode=ceil_mode,
                        count_include_pad=count_include_pad, divisor_override=divisor_override)
            qX_ref = torch.quantize_per_tensor(X_ref, scale=qX_hat.q_scale(), zero_point=qX_hat.q_zero_point(),
                                               dtype=torch_type)

            self.assertEqual(qX_ref.int_repr().to(torch.double), qX_hat.int_repr().to(torch.double), atol=1.0, rtol=0,
                             msg=error_message.format(name, qX_hat.int_repr(), qX_ref.int_repr()))
            self.assertEqual(scale, qX_hat.q_scale(),
                             msg=error_message.format(name + '.scale', scale, qX_hat.q_scale()))
            self.assertEqual(zero_point, qX_hat.q_zero_point(),
                             msg=error_message.format(name + '.zero_point', scale,
                                                      qX_hat.q_zero_point()))

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=5, max_side=10),
                       qparams=hu.qparams(dtypes=torch.qint8)),
           kernel=st.sampled_from((4, 5)),
           stride=st.sampled_from((None, 1, 2)),
           padding=st.integers(0, 2),
           ceil_mode=st.sampled_from((True, False)),
           count_include_pad=st.sampled_from((True, False)),
           divisor_override=st.sampled_from((None, None)))
    def test_avg_pool2d_nhwc(self, X, kernel, stride, padding, ceil_mode, count_include_pad, divisor_override):
        """
        Note: 1) we currently cannot test the divisor_override, because quantized op will clamp the result
        within range. However, the float op will not.
        2) we cannot test the qint32, since the float point precision is much lower than int32 for big number,
        which will make the test be very flaky.
        """
        X, (scale, zero_point, torch_type) = X
        H, W = X.shape[-2:]


        if X.shape[1] < 176:
            X = np.repeat(X, 176 / X.shape[1], 1)

        assume(kernel // 2 >= padding)  # Kernel cannot be overhanging!
        iH, iW = X.shape[-2:]
        oH = pool_output_shape(iH, kernel, padding, stride, dilation=1)
        assume(oH > 0)
        oW = pool_output_shape(iW, kernel, padding, stride, dilation=1)
        assume(oW > 0)

        X_nchw = np.ascontiguousarray(X.transpose([0, 2, 3, 1]))

        qX = torch.quantize_per_tensor(torch.from_numpy(X_nchw), scale=scale,
                                       zero_point=zero_point, dtype=torch_type).permute([0, 3, 1, 2])
        X = qX.dequantize()

        # Run reference on int_repr + round to avoid double rounding error.
        X_ref = torch.nn.functional.avg_pool2d(
            X, kernel_size=kernel, stride=stride, padding=padding,
            ceil_mode=ceil_mode, count_include_pad=count_include_pad, divisor_override=divisor_override)

        self.assertTrue(qX.stride() != sorted(qX.stride()))
        ops_under_test = {
            "nn.functional": torch.nn.functional.avg_pool2d,
            "nn.quantized.functional": torch.nn.quantized.functional.avg_pool2d
        }
        error_message = r"Results are off for {}:\n\tExpected:\n{}\n\tGot:\n{}"
        for name, op in ops_under_test.items():
            X_hat = op(qX, kernel_size=kernel, stride=stride, padding=padding, ceil_mode=ceil_mode,
                       count_include_pad=count_include_pad, divisor_override=divisor_override)
            self.assertTrue(X_hat.stride() != sorted(X_hat.stride()))
            qX_ref = torch.quantize_per_tensor(X_ref, scale=X_hat.q_scale(), zero_point=X_hat.q_zero_point(),
                                               dtype=torch_type)

            self.assertEqual(qX_ref.int_repr().to(torch.double), X_hat.int_repr().to(torch.double), atol=1.0, rtol=0,
                             msg=error_message.format(name, X_hat.int_repr(), qX_ref.int_repr()))
            self.assertEqual(scale, X_hat.q_scale(),
                             msg=error_message.format(name + '.scale', scale, X_hat.q_scale()))
            self.assertEqual(zero_point, X_hat.q_zero_point(),
                             msg=error_message.format(name + '.zero_point', scale,
                             X_hat.q_zero_point()))

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=5, max_dims=5,
                                              min_side=5, max_side=10),
                       qparams=hu.qparams(dtypes=torch.quint8)),
           kernel=st.sampled_from((3, 5)),
           stride=st.sampled_from((None, 1, 2)),
           padding=st.integers(0, 2),
           ceil_mode=st.sampled_from((True, False)),
           count_include_pad=st.sampled_from((True, False)),
           divisor_override=st.sampled_from((None, None)))
    def test_avg_pool3d(self, X, kernel, stride, padding, ceil_mode, count_include_pad, divisor_override):
        """
        Note: we currently cannot test the divisor_override, because quantized op will clamp the result
        within range. However, the float op will not.
        """
        X, (scale, zero_point, torch_type) = X

        assume(kernel // 2 >= padding)  # Kernel cannot be overhanging!
        iD, iH, iW = X.shape[-3:]
        oD = pool_output_shape(iD, kernel, padding, stride, dilation=1)
        assume(oD > 0)
        oH = pool_output_shape(iH, kernel, padding, stride, dilation=1)
        assume(oH > 0)
        oW = pool_output_shape(iW, kernel, padding, stride, dilation=1)
        assume(oW > 0)

        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)
        X = qX.dequantize()
        # Run reference on float tensor and then quantize the result for comparison
        X_ref = torch.nn.functional.avg_pool3d(
            X, kernel_size=kernel, stride=stride, padding=padding,
            ceil_mode=ceil_mode, count_include_pad=count_include_pad, divisor_override=divisor_override)

        ops_under_test = {
            "nn.functional": torch.nn.functional.avg_pool3d,
            "nn.quantized.functional": torch.nn.quantized.functional.avg_pool3d
        }
        error_message = r"Results are off for {}:\n\tExpected:\n{}\n\tGot:\n{}"
        for name, op in ops_under_test.items():
            qX_hat = op(qX, kernel_size=kernel, stride=stride, padding=padding, ceil_mode=ceil_mode,
                        count_include_pad=count_include_pad, divisor_override=divisor_override)
            qX_ref = torch.quantize_per_tensor(X_ref, scale=qX_hat.q_scale(), zero_point=qX_hat.q_zero_point(),
                                               dtype=torch_type)
            self.assertEqual(qX_ref.int_repr().to(torch.double), qX_hat.int_repr().to(torch.double), atol=1.0, rtol=0,
                             msg=error_message.format(name, qX_hat.int_repr(), qX_ref.int_repr()))
            self.assertEqual(scale, qX_hat.q_scale(),
                             msg=error_message.format(name + '.scale', scale, qX_hat.q_scale()))
            self.assertEqual(zero_point, qX_hat.q_zero_point(),
                             msg=error_message.format(name + '.zero_point', scale,
                                                      qX_hat.q_zero_point()))

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=5, max_dims=5,
                                              min_side=5, max_side=10),
                       qparams=hu.qparams(dtypes=torch.qint8)),
           kernel=st.sampled_from((4, 5)),
           stride=st.sampled_from((None, 1, 2)),
           padding=st.integers(0, 2),
           ceil_mode=st.sampled_from((True, False)),
           count_include_pad=st.sampled_from((True, False)),
           divisor_override=st.sampled_from((None, None)))
    def test_avg_pool3d_nhwc(self, X, kernel, stride, padding, ceil_mode, count_include_pad, divisor_override):
        """
        Note: 1) we currently cannot test the divisor_override, because quantized op will clamp the result
        within range. However, the float op will not.
        2) we cannot test the qint32, since the float point precision is much lower than int32 for big number,
        which will make the test be very flaky.
        """
        X, (scale, zero_point, torch_type) = X
        D, H, W = X.shape[-3:]


        if X.shape[1] < 176:
            X = np.repeat(X, 176 / X.shape[1], 1)

        assume(kernel // 2 >= padding)  # Kernel cannot be overhanging!
        iD, iH, iW = X.shape[-3:]
        oD = pool_output_shape(iD, kernel, padding, stride, dilation=1)
        assume(oD > 0)
        oH = pool_output_shape(iH, kernel, padding, stride, dilation=1)
        assume(oH > 0)
        oW = pool_output_shape(iW, kernel, padding, stride, dilation=1)
        assume(oW > 0)

        X_nchw = np.ascontiguousarray(X.transpose([0, 2, 3, 4, 1]))

        qX = torch.quantize_per_tensor(torch.from_numpy(X_nchw), scale=scale,
                                       zero_point=zero_point, dtype=torch_type).permute([0, 4, 1, 2, 3])
        X = qX.dequantize()

        # Run reference on int_repr + round to avoid double rounding error.
        X_ref = torch.nn.functional.avg_pool3d(
            X, kernel_size=kernel, stride=stride, padding=padding,
            ceil_mode=ceil_mode, count_include_pad=count_include_pad, divisor_override=divisor_override)

        self.assertTrue(qX.stride() != sorted(qX.stride()))
        ops_under_test = {
            "nn.functional": torch.nn.functional.avg_pool3d,
            "nn.quantized.functional": torch.nn.quantized.functional.avg_pool3d
        }
        error_message = r"Results are off for {}:\n\tExpected:\n{}\n\tGot:\n{}"
        for name, op in ops_under_test.items():
            X_hat = op(qX, kernel_size=kernel, stride=stride, padding=padding, ceil_mode=ceil_mode,
                       count_include_pad=count_include_pad, divisor_override=divisor_override)
            self.assertTrue(X_hat.stride() != sorted(X_hat.stride()))
            qX_ref = torch.quantize_per_tensor(X_ref, scale=X_hat.q_scale(), zero_point=X_hat.q_zero_point(),
                                               dtype=torch_type)

            self.assertEqual(qX_ref.int_repr().to(torch.double), X_hat.int_repr().to(torch.double), atol=1.0, rtol=0,
                             msg=error_message.format(name, X_hat.int_repr(), qX_ref.int_repr()))
            self.assertEqual(scale, X_hat.q_scale(),
                             msg=error_message.format(name + '.scale', scale, X_hat.q_scale()))
            self.assertEqual(zero_point, X_hat.q_zero_point(),
                             msg=error_message.format(name + '.zero_point', scale,
                             X_hat.q_zero_point()))

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=1, max_side=10),
                       qparams=hu.qparams(dtypes=torch.quint8)),
           output_size_h=st.integers(1, 10),
           output_size_w=st.integers(1, 10))
    def test_adaptive_avg_pool2d(self, X, output_size_h, output_size_w):
        X, (scale, zero_point, torch_type) = X

        H, W = X.shape[-2:]
        assume(output_size_h <= H)
        assume(output_size_w <= W)
        if output_size_h == output_size_w:
            output_size = output_size_h
        else:
            output_size = (output_size_h, output_size_w)
        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch_type)

        # Run reference on int_repr + round to avoid double rounding error.
        X_ref = torch.nn.functional.adaptive_avg_pool2d(
            qX.int_repr().to(torch.float), output_size).round()

        ops_under_test = {
            "nn.functional": torch.nn.functional.adaptive_avg_pool2d,
            "nn.quantized.functional":
                torch.nn.quantized.functional.adaptive_avg_pool2d
        }

        error_message = r"Results are off for {}:\n\tExpected:\n{}\n\tGot:\n{}"

        for name, op in ops_under_test.items():
            qX_hat = op(qX, output_size=output_size)
            # TODO(#38095): Replace assertEqualIgnoreType. See issue #38095
            self.assertEqualIgnoreType(X_ref, qX_hat.int_repr(), atol=1.0, rtol=0,
                                       msg=error_message.format(name, X_ref, qX_hat))
            self.assertEqual(scale, qX_hat.q_scale(),
                             msg=error_message.format(name + '.scale', scale, qX_hat.q_scale()))
            self.assertEqual(zero_point, qX_hat.q_zero_point(),
                             msg=error_message.format(name + '.zero_point', scale,
                                                      qX_hat.q_zero_point()))

    """Tests adaptive average pool operation on NHWC quantized tensors."""
    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=1, max_side=10),
                       qparams=hu.qparams(dtypes=torch.qint8)),
           output_size_h=st.integers(1, 10),
           output_size_w=st.integers(1, 10))
    def test_adaptive_avg_pool2d_nhwc(self, X, output_size_h, output_size_w):
        X, (scale, zero_point, torch_type) = X
        H, W = X.shape[-2:]
        assume(output_size_h <= H)
        assume(output_size_w <= W)
        if output_size_h == output_size_w:
            output_size = output_size_h
        else:
            output_size = (output_size_h, output_size_w)

        if X.shape[1] < 176:
            X = np.repeat(X, 176 / X.shape[1], 1)

        X_nchw = np.ascontiguousarray(X.transpose([0, 2, 3, 1]))
        X = torch.from_numpy(X_nchw).permute([0, 3, 1, 2])
        qX = torch.quantize_per_tensor(torch.from_numpy(X_nchw), scale=scale,
                                       zero_point=zero_point, dtype=torch_type).permute([0, 3, 1, 2])

        # Run reference on int_repr + round to avoid double rounding error.
        X_ref = torch.nn.functional.adaptive_avg_pool2d(qX.int_repr().to(torch.double), output_size).round()

        self.assertTrue(qX.stride() != sorted(qX.stride()))

        ops_under_test = {
            "nn.functional": torch.nn.functional.adaptive_avg_pool2d,
            "nn.quantized.functional":
                torch.nn.quantized.functional.adaptive_avg_pool2d
        }
        error_message = r"Results are off for {}:\n\tExpected:\n{}\n\tGot:\n{}"
        for name, op in ops_under_test.items():
            X_hat = op(qX, output_size=output_size)
            self.assertTrue(X_hat.stride() != sorted(X_hat.stride()))
            # TODO(#38095): Replace assertEqualIgnoreType. See issue #38095
            self.assertEqualIgnoreType(X_ref, X_hat.int_repr(), atol=1.0, rtol=0,
                                       msg="{} results are off".format(name))
            self.assertEqual(scale, X_hat.q_scale(),
                             msg=error_message.format(name + '.scale', scale, X_hat.q_scale()))
            self.assertEqual(zero_point, X_hat.q_zero_point(),
                             msg=error_message.format(name + '.zero_point', scale,
                                                      X_hat.q_zero_point()))

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=3, max_dims=4,
                                              min_side=1, max_side=10),
                       qparams=hu.qparams()),
           k=st.integers(1, 10),
           dim=st.integers(1, 4),
           largest=st.booleans(),
           sorted=st.booleans())
    def test_qtopk(self, X, k, dim, largest, sorted):
        X, (scale, zero_point, torch_type) = X
        qX = torch.quantize_per_tensor(torch.from_numpy(X), scale, zero_point, torch_type)
        assume(dim < X.ndim)
        assume(k < X.shape[dim])

        unquantized_out = torch.topk(qX.dequantize(), k, dim=dim, largest=largest, sorted=sorted)

        values = torch.quantize_per_tensor(torch.from_numpy(X), scale, zero_point, torch_type)
        indices = torch.tensor(torch.from_numpy(X)).long()

        quantized_out = torch.topk(qX, k, dim=dim, largest=largest, sorted=sorted)

        assert(len(unquantized_out) == len(quantized_out))
        torch.testing.assert_allclose(quantized_out[0].dequantize(), unquantized_out[0])
        torch.testing.assert_allclose(quantized_out[1], unquantized_out[1])

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=1, max_side=10),
                       qparams=hu.qparams()),
           k=st.integers(1, 10),
           dim=st.integers(1, 4),
           largest=st.booleans(),
           sorted=st.booleans())
    def test_qtopk_nhwc(self, X, k, dim, largest, sorted):
        # X is NHWC, we permute to view as NCHW but keep NHWC in memory
        X, (scale, zero_point, torch_type) = X
        qX = torch.quantize_per_tensor(torch.from_numpy(X), scale, zero_point, torch_type).permute([0, 3, 1, 2])
        X = np.transpose(X, [0, 3, 1, 2])
        assume(dim < X.ndim)
        assume(k < X.shape[dim])

        unquantized_out = torch.topk(qX.dequantize(), k, dim=dim, largest=largest, sorted=sorted)

        values = torch.quantize_per_tensor(torch.from_numpy(X), scale, zero_point, torch_type)
        indices = torch.tensor(torch.from_numpy(X)).long()

        quantized_out = torch.topk(qX, k, dim=dim, largest=largest, sorted=sorted)

        assert(len(unquantized_out) == len(quantized_out))
        torch.testing.assert_allclose(quantized_out[0].dequantize(), unquantized_out[0])
        torch.testing.assert_allclose(quantized_out[1], unquantized_out[1])


    """Tests quantize concatenation (both fused and not)."""
    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=3, max_dims=4,
                                              min_side=1, max_side=10),
                       qparams=hu.qparams()),
           num=st.integers(1, 4),
           dim=st.integers(1, 4),
           relu=st.booleans())
    def test_cat(self, X, num, dim, relu):
        tensors_q = []
        tensors_ref = []
        X, (scale, zero_point, torch_type) = X
        assume(dim < X.ndim)
        X = torch.from_numpy(X)
        new_shape = np.array(X.shape)
        new_shape[dim] = 0
        for idx in range(num):
            tensors_q.append(torch.quantize_per_tensor(X, scale, zero_point,
                                                       torch_type))
            tensors_ref.append(X)
            new_shape[dim] += tensors_ref[-1].shape[dim]

        cat_ref = torch.cat(tensors_ref, dim=dim)
        cat_ref = torch.quantize_per_tensor(cat_ref, scale, zero_point, torch_type)
        cat_ref = cat_ref.dequantize()

        if relu:
            cat_ref = F.relu(cat_ref)
            q_cat_op = torch.ops.quantized.cat_relu
            q_cat_out_op = torch.ops.quantized.cat_relu_out
        else:
            q_cat_op = torch.ops.quantized.cat
            q_cat_out_op = torch.ops.quantized.cat_out

        cat_q = q_cat_op(tensors_q, dim=dim, scale=scale,
                         zero_point=zero_point)
        cat_q = cat_q.dequantize()
        np.testing.assert_equal(cat_ref.numpy(), cat_q.numpy())

        cat_q_out = torch._empty_affine_quantized(
            list(new_shape), scale=scale,
            zero_point=zero_point, dtype=torch_type)
        q_cat_out_op(tensors_q, dim=dim, out=cat_q_out)
        cat_q_out = cat_q_out.dequantize()
        np.testing.assert_equal(cat_ref.numpy(), cat_q_out.numpy())

        # Test the cat on per-channel quantized tensor.
        ch_axis = 1
        scales = torch.from_numpy(np.array([1.0] * X.shape[ch_axis]))
        scales = scales.to(torch.float64)
        zero_points = torch.from_numpy(np.array([0] * X.shape[ch_axis]))
        zero_points = zero_points.to(torch.long)
        tensors_q[0] = torch.quantize_per_channel(
            X, scales, zero_points, axis=ch_axis, dtype=torch_type)
        with self.assertRaisesRegex(RuntimeError, "supported.*cat"):
            cat_q = q_cat_op(tensors_q, dim=ch_axis, scale=scale,
                             zero_point=zero_point)

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=5, max_side=10),
                       qparams=hu.qparams()),
           size=st.sampled_from((1, 3, 5, 10)),
           mode=st.sampled_from(("bilinear", "nearest")),
           scale_factor=st.sampled_from((None, 1.5, 2.0)),
           align_corners=st.sampled_from((True, False)),
           nhwc_layout=st.sampled_from((True, False)))
    def test_interpolate(self, X, size, mode, scale_factor, align_corners, nhwc_layout):
        """
        This test cover upsample_nearest2d and upsample_bilinear2d
        """
        X, (scale, zero_point, torch_type) = X
        H, W = X.shape[-2:]

        if scale_factor is not None:
            size = None
        if mode == "nearest":
            align_corners = None

        if nhwc_layout:
            if X.shape[1] < 176:
                X = np.repeat(X, 176 / X.shape[1], 1)

            X_nchw = np.ascontiguousarray(X.transpose([0, 2, 3, 1]))
            X = torch.from_numpy(X_nchw).permute([0, 3, 1, 2])

            qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                           dtype=torch_type).permute([0, 3, 1, 2])
        else:
            X = torch.from_numpy(X)
            qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                           dtype=torch_type)

        X_ref = torch.nn.functional.interpolate(
            qX.int_repr().to(torch.float), size=size, scale_factor=scale_factor,
            mode=mode, align_corners=align_corners)

        ops_under_test = {
            "nn.functional": torch.nn.functional.interpolate,
            "nn.quantized.functional": torch.nn.quantized.functional.interpolate
        }
        error_message = r"Results are off for {}:\n\tExpected:\n{}\n\tGot:\n{}"
        for name, op in ops_under_test.items():
            qX_hat = op(qX, size=size, scale_factor=scale_factor,
                        mode=mode, align_corners=align_corners)
            # TODO(#38095): Replace assertEqualIgnoreType. See issue #38095
            self.assertEqualIgnoreType(X_ref, qX_hat.int_repr(), atol=1.0, rtol=0,
                                       msg="{} results are off".format(name, qX_hat.int_repr(), X_ref))
            self.assertEqual(scale, qX_hat.q_scale(),
                             msg=error_message.format(name + '.scale', scale, qX_hat.q_scale()))
            self.assertEqual(zero_point, qX_hat.q_zero_point(),
                             msg=error_message.format(name + '.zero_point', scale,
                                                      qX_hat.q_zero_point()))

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=5, max_dims=5,
                                              min_side=5, max_side=10),
                       qparams=hu.qparams()),
           size=st.sampled_from((1, 3, 5, 5, 10)),
           scale_factor=st.sampled_from((None, 1.5, 2.0)),
           align_corners=st.sampled_from((True, False)),
           nhwc_layout=st.sampled_from((True, False)))
    def test_interpolate3d(self, X, size, scale_factor, align_corners, nhwc_layout):
        """
        This test cover upsample_nearest2d and upsample_bilinear2d
        """
        X, (scale, zero_point, torch_type) = X
        D, H, W = X.shape[-3:]
        mode = "nearest"
        if scale_factor is not None:
            size = None
        if mode == "nearest":
            align_corners = None

        if nhwc_layout:
            if X.shape[1] < 176:
                X = np.repeat(X, 176 / X.shape[1], 1)

            X_nchw = np.ascontiguousarray(X.transpose([0, 2, 3, 4, 1]))
            X = torch.from_numpy(X_nchw).permute([0, 4, 1, 2, 3])

            qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                           dtype=torch_type).permute([0, 4, 1, 2, 3])
        else:
            X = torch.from_numpy(X)
            qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                           dtype=torch_type)
        X_ref = torch.nn.functional.interpolate(
            qX.int_repr().to(torch.float), size=size, scale_factor=scale_factor,
            mode=mode, align_corners=align_corners)

        ops_under_test = {
            "nn.functional": torch.nn.functional.interpolate,
            "nn.quantized.functional": torch.nn.quantized.functional.interpolate
        }

        error_message = r"Results are off for {}:\n\tExpected:\n{}\n\tGot:\n{}"
        for name, op in ops_under_test.items():
            qX_hat = op(qX, size=size, scale_factor=scale_factor,
                        mode=mode, align_corners=align_corners)
            # TODO(#38095): Replace assertEqualIgnoreType. See issue #38095
            self.assertEqualIgnoreType(X_ref, qX_hat.int_repr(), atol=1.0, rtol=0,
                                       msg="{} results are off".format(name, qX_hat.int_repr(), X_ref))
            self.assertEqual(scale, qX_hat.q_scale(),
                             msg=error_message.format(name + '.scale', scale, qX_hat.q_scale()))
            self.assertEqual(zero_point, qX_hat.q_zero_point(),
                             msg=error_message.format(name + '.zero_point', scale,
                                                      qX_hat.q_zero_point()))

    """Tests quantize concatenation (both fused and not)."""
    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=1, max_side=10),
                       qparams=hu.qparams()),
           relu=st.booleans())
    def test_cat_nhwc(self, X, relu):
        # X is NHWC
        X, (scale, zero_point, torch_type) = X

        # Tile out X so # channels is > 64
        X = np.repeat(X, 70 / X.shape[3], 3)
        X = torch.from_numpy(np.ascontiguousarray(X))
        Y = X.clone()
        Y = torch.from_numpy(np.ascontiguousarray(Y))
        # Here, we quantize and get quantized tensors in NHWC for both dims and strides. The
        # permute switches it so that the tensor looks like NCHW but it laid out in memory as
        # NHWC.
        qX = torch.quantize_per_tensor(X, scale, zero_point, torch_type).permute([0, 3, 1, 2])
        qY = torch.quantize_per_tensor(Y, scale, zero_point, torch_type).permute([0, 3, 1, 2])

        ref = torch.cat([qX.dequantize(), qY.dequantize()], dim=1)
        if relu:
            ref[ref < 0] = 0.0
        ref = torch.quantize_per_tensor(ref, scale=scale, zero_point=zero_point, dtype=torch_type)

        if relu:
            out = torch.ops.quantized.cat_relu(
                [qX, qY], dim=1, scale=scale, zero_point=zero_point)
        else:
            out = torch.ops.quantized.cat([qX, qY], dim=1, scale=scale, zero_point=zero_point)

        torch.testing.assert_allclose(out.dequantize(), ref.dequantize())
        self.assertNotEqual(out.stride(), sorted(out.stride()))

    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=3, max_dims=3,
                                              min_side=1, max_side=2),
                       qparams=hu.qparams()),
           dim=st.integers(1, 2))
    def test_mean(self, X, dim):
        X, (scale, zero_point, torch_type) = X
        qX = torch.quantize_per_tensor(torch.tensor(X).float(), scale, zero_point, torch_type)

        Y = torch.mean(qX.dequantize(), dim)
        Y = torch.quantize_per_tensor(Y, scale, zero_point, torch_type).dequantize()
        qY = torch.mean(qX, dim)

        self.assertEqual(Y, qY.dequantize())

    """Tests the correctness of the quantized equal op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams()),
           X2=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                        qparams=hu.qparams()),
           X_per_channel=st.booleans(),
           X2_per_channel=st.booleans())
    def test_equal(self, X, X2, X_per_channel, X2_per_channel):
        X, X_params = X
        (scale, zero_point, torch_type) = X_params
        X2, X2_params = X2
        (scale2, zero_point2, torch_type2) = X2_params

        X = torch.from_numpy(X)
        if X_per_channel:
            X_scheme = 'per_channel'
            channels = X.shape[-1]
            qX = torch.quantize_per_channel(
                X,
                scales=torch.tensor([scale] * channels),
                zero_points=torch.tensor([zero_point] * channels),
                dtype=torch_type,
                axis=X.ndim - 1)
        else:
            X_scheme = 'per_tensor'
            qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                           dtype=torch_type)
        X2 = torch.from_numpy(X2)
        if X2_per_channel:
            X2_scheme = 'per_channel'
            channels = X2.shape[-1]
            qX2 = torch.quantize_per_channel(
                X2,
                scales=torch.tensor([scale2] * channels),
                zero_points=torch.tensor([zero_point2] * channels),
                dtype=torch_type2,
                axis=X2.ndim - 1)
        else:
            X2_scheme = 'per_tensor'
            qX2 = torch.quantize_per_tensor(X2, scale=scale2, zero_point=zero_point2,
                                            dtype=torch_type2)

        def equal_ref(qX, qX2):
            if qX.qscheme() != qX2.qscheme():
                return False
            if qX.shape != qX2.shape:
                return False
            if qX.dtype != qX2.dtype:
                return False
            if qX.qscheme() == torch.per_tensor_affine:
                if qX.q_scale() != qX2.q_scale():
                    return False
                if qX.q_zero_point() != qX2.q_zero_point():
                    return False
            elif qX.qscheme() == torch.per_channel_affine:
                if (qX.q_per_channel_scales() !=
                   qX2.q_per_channel_scales()).any():
                    return False
                if (qX.q_per_channel_zero_points() !=
                   qX2.q_per_channel_zero_points()).any():
                    return False
            else:
                raise NotImplementedError("Don't know what to do with",
                                          qX.qscheme())
            if (qX.int_repr().to(float) != qX2.int_repr().to(float)).any():
                return False
            return True

        self.assertEqual(qX.equal(qX), equal_ref(qX, qX))
        self.assertEqual(qX.equal(qX2), equal_ref(qX, qX2))


    @skipIfNoFBGEMM
    @given(X=hu.tensor(shapes=hu.array_shapes(min_dims=4, max_dims=4,
                                              min_side=1, max_side=32, max_numel=10**5),
                       qparams=hu.qparams(dtypes=(torch.quint8, torch.qint8))),
           Y_scale=st.floats(0.2, 2.6),
           Y_zero_point=st.integers(0, 5))
    def test_batch_norm2d(self, X, Y_scale, Y_zero_point):
        with override_quantized_engine("fbgemm"):
            X, (scale_x, zero_point_x, dtype_x) = X

            X = torch.from_numpy(X)
            c = X.shape[1]

            mean = torch.rand(c).float()
            var = torch.rand(c).float()
            weight = torch.rand(c).float()
            bias = torch.rand(c).float()
            eps = 0.001
            qx = torch.quantize_per_tensor(X, scale_x, zero_point_x, dtype_x)
            qy = torch.ops.quantized.batch_norm2d(qx, weight, bias, mean, var, eps, Y_scale, Y_zero_point)

            float_ref = F.batch_norm(qx.dequantize(), weight=weight, bias=bias,
                                     running_mean=mean, running_var=var, training=False, momentum=0, eps=eps)
            quantize_ref = torch.quantize_per_tensor(float_ref, Y_scale, Y_zero_point, dtype_x)
            self.assertEqual(qy.int_repr().numpy(), quantize_ref.int_repr().numpy())

    @skipIfNoFBGEMM
    def test_group_norm(self):
        # hypothesis is flaky for this test, create test cases manually
        batches_list = (1, 7)
        num_groups_list = (1, 2)
        channels_per_groups = (1, 2)
        elements_per_channels = (8, 17)
        torch_types = (torch.qint8, torch.quint8)
        y_scales = (0.1, 4.23)
        y_zero_points = (0, 1)
        combined = [batches_list, num_groups_list, channels_per_groups, elements_per_channels,
                    torch_types, y_scales, y_zero_points]
        test_cases = itertools.product(*combined)

        with override_quantized_engine("fbgemm"):
            for test_case in test_cases:

                batches, num_groups, channels_per_group, elements_per_channel, \
                    torch_type, Y_scale, Y_zero_point = test_case
                num_channels = num_groups * channels_per_group
                shapes = (batches, num_channels, elements_per_channel)

                # In the FP kernel, sums and sums of squares are calculated in floating point.
                # In the int8 and uint8 versions of the quantized kernel, they are
                # calculated in integer arithmetic (which is exact).
                # Because of this, the numerics do not always match exactly which is
                # expected and acceptable. We do the following to whitelist this failure
                # in this test:
                # 1. do not use Hypothesis to generate the input tensor.  Hypothesis
                #    favors homogeneous inputs in its search strategies which isn't
                #    representative of the inputs we care about, and tends to maximize
                #    this particular numerics difference.
                # 2. whitelist a small % of off by Y_scale errors.  Even when the
                #    variance of the input is high, there can be off by one errors
                #    in the result if the input value happens to fall exactly on
                #    the bin boundary of the output scale.
                #
                # If we want the numerics to match we could switch to calculating
                # mean+var in floating point in the future, at the cost of speed.
                X, X_scale, X_zero_point = \
                    _get_random_tensor_and_q_params(shapes, 1.0, torch_type)

                # Initialize the weights non-randomly for reproducibility
                weight = torch.ones(num_channels).float() * 0.5
                bias = torch.ones(num_channels).float()
                for i in range(num_channels):
                    weight[i] *= i
                    bias[i] *= i

                eps = 0.001

                qX = torch.quantize_per_tensor(X, X_scale, X_zero_point, torch_type)
                dqX = qX.dequantize()

                # Enforce non-homogeneous inputs
                for batch_idx in range(batches):
                    for group_idx in range(num_groups):
                        ch_start = group_idx * channels_per_group
                        ch_end = ch_start + channels_per_group
                        group_vals = dqX[batch_idx][ch_start:ch_end]
                        assume(
                            float(torch.unique(group_vals).shape[0]) / group_vals.numel() > 0.01
                            or group_vals.numel() < 5)

                qY = torch.ops.quantized.group_norm(qX, num_groups, weight, bias, eps, Y_scale, Y_zero_point)

                dqY_hat = F.group_norm(dqX, num_groups=num_groups, weight=weight, bias=bias, eps=eps)
                qY_hat = torch.quantize_per_tensor(dqY_hat, Y_scale, Y_zero_point, torch_type)

                # Due to the numerics difference mentioned above between calculating
                # the variance in float vs int, the results can still be slightly
                # different.
                dqY = qY.dequantize()
                dqY_hat = qY_hat.dequantize()
                diff = dqY - dqY_hat

                # off-by-one errors are magnitude of Y_scale
                num_diff = torch.sum(diff > Y_scale * 1.0001)
                pct_diff = float(num_diff) / (diff.numel() + 1e-5)
                num_diff_off_by_one = torch.sum((diff > 0) * (diff <= Y_scale))
                pct_diff_off_by_one = float(num_diff_off_by_one) / (diff.numel() + 1e-5)

                self.assertTrue(pct_diff < 1e-6)
                self.assertTrue(pct_diff_off_by_one < 0.01)

    @skipIfNoFBGEMM
    def test_instance_norm(self):
        max_sides = (4, 5)
        side_lens = (2, 8, 11)
        torch_types = (torch.qint8, torch.quint8)
        y_scales = (0.1, 4.23)
        y_zero_points = (0, 1)
        combined = [max_sides, side_lens, torch_types, y_scales, y_zero_points]
        test_cases = itertools.product(*combined)

        with override_quantized_engine("fbgemm"):
            for test_case in test_cases:

                max_side, side_len, torch_type, Y_scale, Y_zero_point = test_case
                shapes = [side_len] * max_side

                # In the FP kernel, sums and sums of squares are calculated in floating point.
                # In the int8 and uint8 versions of the quantized kernel, they are
                # calculated in integer arithmetic (which is exact).
                # Because of this, the numerics do not always match exactly which is
                # expected and acceptable. We do the following to whitelist this failure
                # in this test:
                # 1. do not use Hypothesis to generate the input tensor.  Hypothesis
                #    favors homogeneous inputs in its search strategies which isn't
                #    representative of the inputs we care about, and tends to maximize
                #    this particular numerics difference.
                # 2. whitelist a small % of off by Y_scale errors.  Even when the
                #    variance of the input is high, there can be off by one errors
                #    in the result if the input value happens to fall exactly on
                #    the bin boundary of the output scale.
                #
                # If we want the numerics to match we could switch to calculating
                # mean+var in floating point in the future, at the cost of speed.
                X, X_scale, X_zero_point = \
                    _get_random_tensor_and_q_params(shapes, 1.0, torch_type)

                num_channels = shapes[1]
                weight = torch.rand(num_channels).float() * 0.5
                bias = torch.rand(num_channels).float()
                for i in range(num_channels):
                    weight[i] *= i
                    bias[i] *= i
                eps = 0.001

                qX = torch.quantize_per_tensor(X, X_scale, X_zero_point, torch_type)
                dqX = qX.dequantize()

                # Enforce non-homogeneous inputs
                batches = shapes[0]
                for batch_idx in range(batches):
                    for ch_idx in range(num_channels):
                        ch_vals = dqX[batch_idx][ch_idx]
                        assume(
                            float(torch.unique(ch_vals).shape[0]) / ch_vals.numel() > 0.01
                            or group_vals.numel() < 5)

                qY = torch.ops.quantized.instance_norm(qX, weight, bias, eps, Y_scale, Y_zero_point)

                dqY_hat = F.instance_norm(dqX, weight=weight, bias=bias, eps=eps)
                qY_hat = torch.quantize_per_tensor(dqY_hat, Y_scale, Y_zero_point, torch_type)

                # Due to the numerics difference mentioned above between calculating
                # the variance in float vs int, the results can still be slightly
                # different.
                dqY = qY.dequantize()
                dqY_hat = qY_hat.dequantize()
                diff = dqY - dqY_hat

                # off-by-one errors are magnitude of Y_scale
                num_diff = torch.sum(diff > Y_scale * 1.0001)
                pct_diff = float(num_diff) / (diff.numel() + 1e-5)
                num_diff_off_by_one = torch.sum((diff > 0) * (diff <= Y_scale))
                pct_diff_off_by_one = float(num_diff_off_by_one) / (diff.numel() + 1e-5)

                self.assertTrue(pct_diff < 1e-6)
                self.assertTrue(pct_diff_off_by_one < 0.01)

    @skipIfNoFBGEMM
    def test_batch_norm2d_relu(self):
        # hypothesis too slow for this test, create test cases manually
        max_sides = (4, 5)
        side_lens = (1, 8, 11)
        torch_types = (torch.qint8, torch.quint8)
        combined = [max_sides, side_lens, torch_types]
        test_cases = itertools.product(*combined)

        with override_quantized_engine("fbgemm"):
            for test_case in test_cases:
                max_side, side_len, torch_type = test_case
                Y_zero_point = 1
                Y_scale = 0.5

                shapes = [side_len] * max_side
                X, scale_x, zero_point_x = \
                    _get_random_tensor_and_q_params(shapes, 1.0, torch_type)
                dtype_x = torch_type

                c = X.shape[1]
                mean = torch.rand(c).float()
                var = torch.rand(c).float()
                weight = torch.rand(c).float()
                bias = torch.rand(c).float()
                eps = 0.001
                qx = torch.quantize_per_tensor(X, scale_x, zero_point_x, dtype_x)
                if len(X.shape) == 4:
                    qy = torch.ops.quantized.batch_norm2d_relu(
                        qx, weight, bias, mean, var, eps, Y_scale, Y_zero_point)
                else:
                    qy = torch.ops.quantized.batch_norm3d_relu(
                        qx, weight, bias, mean, var, eps, Y_scale, Y_zero_point)


                float_ref = F.batch_norm(qx.dequantize(), weight=weight, bias=bias,
                                         running_mean=mean, running_var=var,
                                         training=False, momentum=0, eps=eps).numpy()

                float_ref_relu = float_ref.copy()
                float_ref_relu[float_ref < 0] = 0
                quantize_ref = torch.quantize_per_tensor(
                    torch.from_numpy(float_ref_relu), Y_scale, Y_zero_point, dtype_x)
                self.assertEqual(
                    qy.int_repr().numpy(),
                    quantize_ref.int_repr().numpy(),
                    msg="{} vs {}".format(qy, quantize_ref))

    @skipIfNoFBGEMM
    def test_batch_norm3d(self):
        # hypothesis too slow for this test, create test cases manually
        side_lens = (1, 8, 11)
        torch_types = (torch.qint8, torch.quint8)
        combined = [side_lens, torch_types]
        test_cases = itertools.product(*combined)

        with override_quantized_engine("fbgemm"):
            for test_case in test_cases:
                max_side = 5
                side_len, torch_type = test_case
                Y_zero_point = 1
                Y_scale = 0.5

                shapes = [side_len] * max_side
                X, scale_x, zero_point_x = \
                    _get_random_tensor_and_q_params(shapes, 1.0, torch_type)
                dtype_x = torch_type

                c = X.shape[1]
                mean = torch.rand(c).float()
                var = torch.rand(c).float()
                weight = torch.rand(c).float()
                bias = torch.rand(c).float()
                eps = 0.001
                qx = torch.quantize_per_tensor(X, scale_x, zero_point_x, dtype_x)
                qy = torch.ops.quantized.batch_norm3d(
                    qx, weight, bias, mean, var, eps, Y_scale, Y_zero_point)

                float_ref = F.batch_norm(qx.dequantize(), weight=weight, bias=bias,
                                         running_mean=mean, running_var=var, training=False,
                                         momentum=0, eps=eps)
                quantize_ref = torch.quantize_per_tensor(float_ref, Y_scale, Y_zero_point, dtype_x)
                self.assertEqual(
                    qy.int_repr().numpy(), quantize_ref.int_repr().numpy(),
                    msg="{} vs {}".format(qy, quantize_ref))

    @override_qengines
    def test_empty_batch(self):
        scale = 1.0
        zero_point = 0
        X = torch.ones((0, 2, 4, 4), dtype=torch.float32)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch.quint8)
        # relu
        qY = torch.nn.functional.relu(qX)
        np.testing.assert_equal(qY.size(), qX.size(),
                                "Quantized relu with batch size 0 failed.")

        # tanh
        qY = torch.tanh(qX)
        np.testing.assert_equal(qY.size(), qX.size(),
                                "Quantized tanh with batch size 0 failed.")
        # sigmoid
        qY = torch.sigmoid(qX)
        np.testing.assert_equal(qY.size(), qX.size(),
                                "Quantized sigmoid with batch size 0 failed.")

        # interpolate
        op = torch.nn.quantized.functional.interpolate
        for mode in ["nearest", "bilinear"]:
            qY = op(qX, scale_factor=2, mode=mode)
            np.testing.assert_equal(qY.size(), (0, 2, 8, 8),
                                    "Quantized interpolate with batch size 0 failed.")

        # avg_pool
        kernel = (2, 2)
        stride = (1, 1)
        padding = (0, 0)
        op = torch.nn.quantized.functional.avg_pool2d
        qY = op(qX, kernel, stride, padding)
        np.testing.assert_equal(qY.size(), (0, 2, 3, 3),
                                "Quantized avg_pool2d with batch size 0 failed.")

        # adaptive_avg_pool
        op = torch.nn.quantized.functional.adaptive_avg_pool2d
        qY = op(qX, (3, 3))
        np.testing.assert_equal(qY.size(), (0, 2, 3, 3),
                                "Quantized adaptive_avg_pool2d with batch size 0 failed.")

        # max_pool
        dilation = (1, 1)
        qY = torch.ops.quantized.max_pool2d(qX, kernel, stride, padding, dilation, ceil_mode=False)
        oH = pool_output_shape(4, 2, 0, 1, 1)
        oW = pool_output_shape(4, 2, 0, 1, 1)
        np.testing.assert_equal(qY.size(), (0, 2, oH, oW),
                                "Quantized maxpool2d with batch size 0 failed.")

        # hardtanh
        qY = torch.nn.quantized.functional.hardtanh(qX, -1, 6)
        np.testing.assert_equal(qY.size(), qX.size(),
                                "Quantized hardtanh with batch size 0 failed.")

        # mul
        qY = torch.ops.quantized.mul(qX, qX, 1.0, 0)
        np.testing.assert_equal(qY.size(), qX.size(),
                                "Quantized mul with batch size 0 failed.")
        # add
        qY = torch.ops.quantized.add(qX, qX, 1.0, 0)
        np.testing.assert_equal(qY.size(), qX.size(),
                                "Quantized addition with batch size 0 failed.")

        # conv
        w = torch.randn((2, 2, 2, 2), dtype=torch.float)
        qw = torch.quantize_per_tensor(w, scale=1.0, zero_point=0, dtype=torch.qint8)
        bias_float = torch.ones(2, dtype=torch.float)
        strides = [1, 1]
        pads = [0, 0]
        dilations = [1, 1]

        w_packed = torch.ops.quantized.conv2d_prepack(qw, bias_float, strides, pads, dilations, 1)
        result = torch.ops.quantized.conv2d(qX, w_packed, 1.0, 0)
        self.assertEqual(result.shape, (0, 2, 3, 3))

        # linear
        X = torch.ones((0, 2), dtype=torch.float32)
        qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                       dtype=torch.quint8)
        w = torch.randn((2, 2), dtype=torch.float)
        qw = torch.quantize_per_tensor(w, scale=1.0, zero_point=0, dtype=torch.qint8)
        w_packed = torch.ops.quantized.linear_prepack(qw, bias_float)
        result = torch.ops.quantized.linear(qX, w_packed, 1.0, 0)
        self.assertEqual(result.shape, (0, 2))

class TestDynamicQuantizedLinear(TestCase):
    """Tests the correctness of the dynamic quantized linear and linear_relu op."""
    @given(
        batch_size=st.integers(1, 4),
        input_channels=st.integers(16, 32),
        output_channels=st.integers(4, 8),
        use_bias=st.booleans(),
        use_relu=st.booleans(),
        use_multi_dim_input=st.booleans(),
        use_channelwise=st.booleans())
    @override_qengines
    def test_qlinear(self, batch_size, input_channels, output_channels,
                     use_bias, use_relu, use_multi_dim_input, use_channelwise):

        if torch.backends.quantized.engine == 'qnnpack':
            use_relu = False

        qlinear_prepack = torch.ops.quantized.linear_prepack
        if use_relu:
            qlinear_dynamic = torch.ops.quantized.linear_relu_dynamic
        else:
            qlinear_dynamic = torch.ops.quantized.linear_dynamic

        if use_multi_dim_input:
            batch_size *= 3  # Test the multi-dim input tensor

        X_scale = 1.0
        X_zp = 0
        X_value_min = 0
        X_value_max = 255
        X_q0 = np.round(np.random.rand(batch_size, input_channels) *
                        (X_value_max - X_value_min)
                        + X_value_min
                        ).astype(np.uint8)
        X_q0 = np.round(np.random.rand(batch_size, input_channels) *
                        (X_value_max - X_value_min) + X_value_min).astype(np.uint8)
        X_q0[0, 0] = X_value_min
        X_q0[0, 1] = X_value_max

        # W_scale = 1.0
        # W_zp = 0
        W_scales = np.ones(output_channels)
        W_zps = np.zeros(output_channels).astype(np.int)
        W_value_min = -128
        W_value_max = 127
        W_q0 = np.round(
            np.random.rand(output_channels, input_channels)
            * (W_value_max - W_value_min)
            + W_value_min
        ).astype(np.int8)
        W_q0[0, 0] = W_value_min
        W_q0[1, 0] = W_value_max

        b_value_min = -10
        b_value_max = 10
        b_q0 = np.round(
            np.random.rand(output_channels) *
            (b_value_max - b_value_min) + b_value_min
        ).astype(np.int32) if use_bias else None

        if torch.backends.quantized.engine == 'fbgemm':
            avoid_vpmaddubsw_overflow_linear(
                batch_size,
                input_channels,
                output_channels,
                X_q0,
                X_value_min,
                X_value_max,
                W_q0,
                W_value_min,
                W_value_max,
            )

        X_fp32 = torch.from_numpy(_dequantize(X_q0, X_scale, X_zp)).to(dtype=torch.float)
        if use_multi_dim_input:
            X_fp32 = X_fp32.view(3, int(batch_size / 3), input_channels)

        # W_scale, W_zp = _calculate_dynamic_qparams(W_fp32, torch.qint8)
        # We currently only check the case where W_scale = 1.0, W_zp = 0.

        if use_channelwise:
            W_fp32 = torch.from_numpy(_dequantize(W_q0, W_scales.reshape(
                (-1, 1)), W_zps.reshape((-1, 1)))).to(dtype=torch.float)
            W_q = torch.quantize_per_channel(W_fp32, scales=torch.from_numpy(W_scales),
                                             zero_points=torch.from_numpy(W_zps), axis=0, dtype=torch.qint8)
            b_fp32 = torch.from_numpy(
                _dequantize(b_q0, X_scale * W_scales, 0)
            ).to(dtype=torch.float) if use_bias else None
        else:
            W_fp32 = torch.from_numpy(_dequantize(
                W_q0, W_scales[0], W_zps[0])).to(dtype=torch.float)
            W_q = torch.quantize_per_tensor(W_fp32, scale=W_scales[0], zero_point=(
                W_zps[0].astype(int).item()), dtype=torch.qint8)
            b_fp32 = torch.from_numpy(
                _dequantize(b_q0, X_scale * int(W_scales[0].item()), 0)
            ).to(dtype=torch.float) if use_bias else None

        # Observe X_fp32 and determine X_scale and X_zero_point, this should match
        # internals of dynamic linear.
        X_scale, X_zp = _calculate_dynamic_qparams(X_fp32, torch.quint8)
        X_q = torch.quantize_per_tensor(X_fp32, scale=X_scale, zero_point=X_zp, dtype=torch.quint8)

        # Weight prepacking operator for dynamic quantized Linear
        W_prepack = qlinear_prepack(W_q, b_fp32)
        # Dynamic quantized Linear operator with prepacked weight
        Y_fp32 = qlinear_dynamic(X_q.dequantize(), W_prepack)
        # Y_fp32 = qlinear_dynamic(X_fp32, W_prepack, b_fp32)

        Y_fp32_ref = F.linear(X_q.dequantize(), W_q.dequantize(), b_fp32)
        # Y_fp32_ref = F.linear(X_fp32, W_fp32, b_fp32)
        # if use_multi_dim_input:
        #     Y_fp32_ref = Y_fp32_ref.view(3, int(batch_size / 3), output_channels)

        if use_relu:
            Y_fp32_ref[Y_fp32_ref < 0.0] = 0.0

        self.assertEqual(Y_fp32, Y_fp32_ref,
                         msg="torch.ops.quantized.linear_dynamic (fbgemm) results are off")

    @skipIfNoFBGEMM
    @given(
        batch_size=st.integers(1, 4),
        input_channels=st.integers(16, 32),
        output_channels=st.integers(4, 8),
    )
    def test_qlinear_legacy(self, batch_size, input_channels, output_channels):
        X_scale = 1.0
        X_zp = 0
        X_value_min = 0
        X_value_max = 255
        X_q0 = np.round(np.random.rand(batch_size, input_channels) * (
            X_value_max - X_value_min) + X_value_min
        ).astype(np.uint8)
        X_q0[0, 0] = X_value_min
        X_q0[0, 1] = X_value_max

        W_scale = 1.0
        W_zp = 0
        W_value_min = -128
        W_value_max = 127
        W_q0 = np.round(
            np.random.rand(output_channels, input_channels)
            * (W_value_max - W_value_min)
            + W_value_min
        ).astype(np.int8)
        W_q0[0, 0] = W_value_min
        W_q0[1, 0] = W_value_max

        b_value_min = -10
        b_value_max = 10
        b_q0 = np.round(
            np.random.rand(output_channels) * (b_value_max - b_value_min) +
            b_value_min
        ).astype(np.int32)

        avoid_vpmaddubsw_overflow_linear(
            batch_size,
            input_channels,
            output_channels,
            X_q0,
            X_value_min,
            X_value_max,
            W_q0,
            W_value_min,
            W_value_max,
        )

        X_fp32 = torch.from_numpy(_dequantize(X_q0, X_scale, X_zp)).to(dtype=torch.float)
        W_fp32 = torch.from_numpy(_dequantize(W_q0, W_scale, W_zp)).to(dtype=torch.float)
        b_fp32 = torch.from_numpy(
            _dequantize(b_q0, X_scale * W_scale, 0)
        ).to(dtype=torch.float)

        W_scale, W_zp = _calculate_dynamic_qparams(W_fp32, torch.qint8)
        W_q = torch.quantize_per_tensor(W_fp32, scale=W_scale, zero_point=W_zp, dtype=torch.qint8)

        # Observe X_fp32 and determine X_scale and X_zero_point, this should match
        # internals of dynamic linear.
        X_scale, X_zp = _calculate_dynamic_qparams(X_fp32, torch.quint8)
        X_q = torch.quantize_per_tensor(X_fp32, scale=X_scale, zero_point=X_zp, dtype=torch.quint8)

        W_int8, col_offsets, W_scale, W_zp = torch.fbgemm_linear_quantize_weight(W_q.dequantize())
        W_prepack = torch.fbgemm_pack_quantized_matrix(W_int8.clone(), W_int8.size(1), W_int8.size(0))
        # Quantized Linear operator with prepacked weight
        Y_fp32 = torch.fbgemm_linear_int8_weight(
            X_q.dequantize(), W_q.dequantize(), W_prepack, col_offsets,
            W_scale, W_zp, b_fp32)

        Y_fp32_ref = F.linear(X_q.dequantize(), W_q.dequantize(), b_fp32)
        # Y_fp32_ref = F.linear(X_fp32, W_fp32, b_fp32)

        self.assertEqual(Y_fp32, Y_fp32_ref,
                         msg="torch.ops.quantized.fbgemm_linear_dynamic results are off")

class TestQuantizedLinear(unittest.TestCase):
    """Tests the correctness of the quantized linear and linear_relu op."""
    @given(batch_size=st.integers(1, 4),
           input_channels=st.integers(16, 32),
           output_channels=st.integers(4, 8),
           use_bias=st.booleans(),
           use_relu=st.booleans(),
           use_multi_dim_input=st.booleans(),
           use_channelwise=st.booleans())
    @override_qengines
    def test_qlinear(self, batch_size, input_channels, output_channels, use_bias,
                     use_relu, use_multi_dim_input, use_channelwise):
        decimal_val = 4
        if torch.backends.quantized.engine == 'qnnpack':
            use_multi_dim_input = False
            # QNNPACK supports uint8 in the kernels. In the op we shift the int8
            # weight values to uint8 to be on par with fbgemm. However, this causes
            # some rounding issues in rare cases. So, we relax the check to allow
            # off by one results.
            decimal_val = 0

        qlinear_prepack = torch.ops.quantized.linear_prepack
        if use_relu:
            qlinear = torch.ops.quantized.linear_relu
        else:
            qlinear = torch.ops.quantized.linear
        if use_multi_dim_input:
            batch_size *= 3  # Test the multi-dim input tensor
        X_scale = 1.5
        X_zp = 5
        X_value_min = 0
        X_value_max = 225
        X_q0 = np.round(
            np.random.rand(batch_size, input_channels) *
            (X_value_max - X_value_min)
            + X_value_min
        ).astype(np.uint8)
        W_scales = np.random.rand(output_channels)
        W_zps = np.round(np.random.rand(output_channels) * 100 - 50).astype(np.int)
        W_value_min = -128
        W_value_max = 127
        W_q0 = np.round(
            np.random.rand(output_channels, input_channels)
            * (W_value_max - W_value_min)
            + W_value_min
        ).astype(np.int8)
        b_value_min = -10
        b_value_max = 10
        b_q0 = np.round(
            np.random.rand(output_channels) *
            (b_value_max - b_value_min) + b_value_min
        ).astype(np.int32) if use_bias else None
        avoid_vpmaddubsw_overflow_linear(
            batch_size,
            input_channels,
            output_channels,
            X_q0,
            X_value_min,
            X_value_max,
            W_q0,
            W_value_min,
            W_value_max,
        )
        X = torch.from_numpy(_dequantize(
            X_q0, X_scale, X_zp)).to(dtype=torch.float)
        X_q = torch.quantize_per_tensor(
            X, scale=X_scale, zero_point=X_zp, dtype=torch.quint8)
        if use_channelwise:
            W = torch.from_numpy(_dequantize(W_q0, W_scales.reshape(
                (-1, 1)), W_zps.reshape((-1, 1)))).to(dtype=torch.float)
            W_q = torch.quantize_per_channel(W, scales=torch.from_numpy(W_scales),
                                             zero_points=torch.from_numpy(W_zps), axis=0, dtype=torch.qint8)
            b = torch.from_numpy(_dequantize(
                b_q0, X_scale * W_scales, 0)).to(dtype=torch.float) if use_bias else None
            b_q = torch.quantize_per_channel(b, scales=torch.from_numpy(X_scale * W_scales),
                                             zero_points=torch.zeros(output_channels, dtype=torch.long),
                                             axis=0, dtype=torch.qint32) if use_bias else None
        else:
            W = torch.from_numpy(_dequantize(
                W_q0, W_scales[0], W_zps[0])).to(dtype=torch.float)
            W_q = torch.quantize_per_tensor(W, scale=W_scales[0], zero_point=(
                W_zps[0].astype(int).item()), dtype=torch.qint8)
            b = torch.from_numpy(_dequantize(
                b_q0, X_scale * (W_scales[0].item()), 0)).to(dtype=torch.float) if use_bias else None
            b_q = torch.quantize_per_tensor(
                b, scale=X_scale * (W_scales[0].item()), zero_point=0, dtype=torch.qint32) if use_bias else None
        # Compare X_scale * W_scale * input_channels * X_value_max * W_value_max with
        # Y_scale * 255 (max for uint8).
        Y_scale = 125.1234
        Y_zp = 5
        # Weight prepacking operator for quantized Linear
        float_bias = b if use_bias else None
        W_prepack = qlinear_prepack(W_q, float_bias)
        if use_multi_dim_input:
            X_q = X_q.view(3, int(batch_size / 3), input_channels)
        # Quantized Linear operator with prepacked weight
        Y_q = qlinear(X_q, W_prepack, Y_scale, Y_zp)
        if not use_channelwise:
            # Test the per-tensor quantization only
            # Reference quantized Linear operator
            Y_q_ref = qlinear_ref(X_q0, X_scale, X_zp, W_q0,
                                  W_scales[0], W_zps[0], b_q0, Y_scale, Y_zp)
            if use_relu:
                Y_q_ref[Y_q_ref < Y_zp] = Y_zp
            if use_multi_dim_input:
                Y_q_ref = np.reshape(
                    Y_q_ref, (3, int(batch_size / 3), output_channels))
            # Assert equal
            np.testing.assert_array_almost_equal(Y_q_ref, Y_q.int_repr().numpy(), decimal=decimal_val)
        # Test both per-tensor and per-channel quantization
        # Reference quantized result from PyTorch Linear operator
        W_fp32 = W_q.dequantize().to(dtype=torch.float)
        X_fp32 = X_q.dequantize().to(dtype=torch.float)
        b_fp32 = b_q.dequantize().to(dtype=torch.float) if use_bias else None
        Y_fp32_ref = F.linear(X_fp32, W_fp32, b_fp32)
        if use_relu:
            Y_fp32_ref[Y_fp32_ref < 0.0] = 0.0
        Y_q_ref2 = torch.quantize_per_tensor(
            Y_fp32_ref, Y_scale, Y_zp, torch.quint8)
        # Assert equal
        np.testing.assert_array_almost_equal(
            Y_q_ref2.int_repr().numpy(), Y_q.int_repr().numpy(), decimal=decimal_val)

    """Tests the correctness of the quantized::linear_unpack op."""
    @given(W=hu.tensor(shapes=hu.array_shapes(2, 2,),
                       qparams=hu.qparams(dtypes=torch.qint8)),
           use_channelwise=st.booleans())
    @override_qengines
    def test_qlinear_unpack(self, W, use_channelwise):

        W, (W_scale, W_zp, torch_type) = W
        if use_channelwise:
            output_channels = W.shape[0]
            W_scales = torch.rand(output_channels).to(torch.double)
            W_zps = torch.round(torch.rand(output_channels)
                                * 100 - 50).to(torch.int64)
        qlinear_prepack = torch.ops.quantized.linear_prepack
        qlinear_unpack = torch.ops.quantized.linear_unpack

        W = torch.from_numpy(W)
        if use_channelwise:
            W_q = torch.quantize_per_channel(
                W, W_scales, W_zps, 0, dtype=torch_type)
        else:
            W_q = torch.quantize_per_tensor(W, scale=W_scale, zero_point=W_zp,
                                            dtype=torch_type)
        # Weight prepacking operator for quantized Linear
        W_prepack = qlinear_prepack(W_q)
        # Weight unpack operator for quantized Linear (Used for serialization)
        W_q_origin = qlinear_unpack(W_prepack)[0]
        # Assert equal
        np.testing.assert_equal(W_q.int_repr(), W_q_origin.int_repr().numpy())
        if use_channelwise:
            np.testing.assert_array_almost_equal(np.float32(W_q.q_per_channel_scales().numpy()),
                                                 np.float32(
                                                     W_q_origin.q_per_channel_scales().numpy()),
                                                 decimal=4)
            np.testing.assert_equal(W_q.q_per_channel_zero_points(
            ).numpy(), W_q_origin.q_per_channel_zero_points().numpy())
        else:
            np.testing.assert_equal(np.float32(
                W_q.q_scale()), np.float32(W_q_origin.q_scale()))
            np.testing.assert_equal(
                W_q.q_zero_point(), W_q_origin.q_zero_point())

class TestQuantizedConv(unittest.TestCase):
    def _test_qconv_unpack_impl(
        self, qconv_prepack_fn, qconv_unpack_fn, inputs, strides, pads,
        channelwise
    ):
        (X_data, W_data, bias_data, groups) = inputs
        (X, (X_scale, X_zero_point, X_qtype)) = X_data
        (W, (W_scale, W_zero_point, W_qtype)) = W_data
        (bias, (bias_scale, bias_zero_point, bias_qtype)) = bias_data
        if channelwise:
            output_channels = W.shape[0]
            W_scale = torch.tensor([W_scale] * output_channels)
            W_zero_point = torch.tensor([W_zero_point] * output_channels)

        W = torch.from_numpy(W).float()
        bias = torch.from_numpy(bias).float()
        if channelwise:
            W_q = torch.quantize_per_channel(
                W, scales=W_scale, zero_points=W_zero_point, axis=0,
                dtype=W_qtype)
        else:
            W_q = torch.quantize_per_tensor(
                W, scale=W_scale, zero_point=W_zero_point, dtype=W_qtype)
        if isinstance(strides, int):
            dilations = [1]
        else:
            dilations = (1,) * len(strides)

        W_packed = qconv_prepack_fn(W_q, bias, strides, pads, dilations, groups)
        (W_unpacked, bias) = qconv_unpack_fn(W_packed)

        # Assert equal
        np.testing.assert_equal(W_q.int_repr().numpy(),
                                W_unpacked.int_repr().numpy())
        if channelwise:
            np.testing.assert_array_almost_equal(
                np.float32(W_q.q_per_channel_scales().numpy()),
                np.float32(W_unpacked.q_per_channel_scales().numpy()),
                decimal=4)
            np.testing.assert_equal(W_q.q_per_channel_zero_points(
            ).numpy(), W_unpacked.q_per_channel_zero_points().numpy())
        else:
            np.testing.assert_equal(np.float32(
                W_q.q_scale()), np.float32(W_unpacked.q_scale()))
            np.testing.assert_equal(
                W_q.q_zero_point(), W_unpacked.q_zero_point())

    def _make_qconv_tensors(
        self, batch_size,
        input_channels_per_group, input_feature_map_shape,
        output_channels_per_group, groups, kernels, strides, pads, dilations,
        X_scale, X_zero_point, W_scale, W_zero_point,
        use_bias, use_channelwise
    ):
        input_channels = input_channels_per_group * groups
        output_channels = output_channels_per_group * groups
        # Padded input size should be at least as big as dilated kernel
        kernels = _single(kernels)
        strides = _single(strides)
        pads = _single(pads)
        dilations = _single(dilations)
        for i in range(len(kernels)):
            assume(input_feature_map_shape[i] + 2 * pads[i]
                   >= dilations[i] * (kernels[i] - 1) + 1)
        W_scale = W_scale * output_channels
        W_zero_point = W_zero_point * output_channels
        # Resize W_scale and W_zero_points arrays equal to output_channels
        W_scale = W_scale[:output_channels]
        W_zero_point = W_zero_point[:output_channels]
        # For testing, we use small values for weights and for activations
        # so that no overflow occurs in vpmaddubsw instruction. If the
        # overflow occurs in qconv implementation and if there is no
        # overflow
        # In reference we can't exactly match the results with reference.
        # Please see the comment in qconv implementation file
        # aten/src/ATen/native/quantized/cpu/qconv.cpp for more details.
        (W_value_min, W_value_max) = (-5, 5)
        # the operator expects them in the format
        # (output_channels, input_channels/groups,
        #  kernel_d, kernel_h, kernel_w)
        W_init = torch.randint(
            W_value_min,
            W_value_max,
            (output_channels, input_channels_per_group,) + kernels,
        )
        b_init = torch.randint(0, 10, (output_channels,))

        (X_value_min, X_value_max) = (0, 4)
        X_init = torch.randint(
            X_value_min,
            X_value_max,
            (batch_size, input_channels,) + input_feature_map_shape,
        )
        X = X_scale * (X_init - X_zero_point).float()

        if use_channelwise:
            W_shape = (-1, 1) + (1,) * len(kernels)
            W_scales_tensor = torch.tensor(W_scale, dtype=torch.float)
            W_zero_points_tensor = torch.tensor(W_zero_point, dtype=torch.float)
            W = W_scales_tensor.reshape(*W_shape) * (
                W_init.float() - W_zero_points_tensor.reshape(*W_shape)).float()
            b = X_scale * W_scales_tensor * b_init.float()
        else:
            W = W_scale[0] * (W_init - W_zero_point[0]).float()
            b = X_scale * W_scale[0] * b_init.float()

        X_q = torch.quantize_per_tensor(
            X, scale=X_scale, zero_point=X_zero_point, dtype=torch.quint8)
        if use_channelwise:
            W_q = torch.quantize_per_channel(
                W, W_scales_tensor, W_zero_points_tensor.long(), 0,
                dtype=torch.qint8)
        else:
            W_q = torch.quantize_per_tensor(
                W, scale=W_scale[0], zero_point=W_zero_point[0],
                dtype=torch.qint8)

        bias_float = b if use_bias else None

        return (X, W), (X_q, W_q), bias_float

    def _test_qconv_impl(
        self, qconv_fn, qconv_prepack_fn, conv_op, batch_size,
        input_channels_per_group, input_feature_map_shape,
        output_channels_per_group, groups, kernels, strides, pads, dilations,
        X_scale, X_zero_point, W_scale, W_zero_point, Y_scale, Y_zero_point,
        use_bias, use_relu, use_channelwise
    ):
        (X, W), (X_q, W_q), bias_float = self._make_qconv_tensors(
            batch_size, input_channels_per_group, input_feature_map_shape,
            output_channels_per_group, groups, kernels,
            strides, pads, dilations, X_scale, X_zero_point, W_scale,
            W_zero_point, use_bias, use_channelwise)
        # Assign weights
        conv_op.weight = torch.nn.Parameter(W, requires_grad=False)
        conv_op.bias = torch.nn.Parameter(
            bias_float, requires_grad=False) if use_bias else None
        result_ref = conv_op(X)
        if use_relu:
            relu = torch.nn.ReLU()
            result_ref = relu(result_ref)

        # Quantize reference results for comparison
        result_ref_q = torch.quantize_per_tensor(
            result_ref, scale=Y_scale, zero_point=Y_zero_point,
            dtype=torch.quint8)

        W_prepack = qconv_prepack_fn(
            W_q, bias_float, strides, pads, dilations, groups)
        Y_q = qconv_fn(
            X_q,
            W_prepack,
            Y_scale,
            Y_zero_point,
        )
        # Make sure the results match
        # assert_array_almost_equal compares using the following formula:
        #     abs(desired-actual) < 1.5 * 10**(-decimal)
        # (https://docs.scipy.org/doc/numpy/reference/generated/numpy.testing.assert_almost_equal.html)
        # We use decimal = 0 to ignore off-by-1 differences between
        # reference and test. Off-by-1 differences arise due to the order of
        # round and zero_point addition operation, i.e., if addition
        # followed by round is used by reference and round followed by
        # addition is used by test, the results may differ by 1.
        # For example, the result of round(2.5) + 1 is 3 while
        # round(2.5 + 1) is 4 assuming the rounding mode is
        # round-to-nearest, ties-to-even.
        np.testing.assert_array_almost_equal(
            result_ref_q.int_repr().numpy(), Y_q.int_repr().numpy(), decimal=0)

    """Tests the correctness of quantized convolution op."""
    @given(batch_size=st.integers(1, 3),
           input_channels_per_group=st.sampled_from([2, 4, 5, 8, 16, 32]),
           height=st.integers(10, 16),
           width=st.integers(7, 14),
           output_channels_per_group=st.sampled_from([2, 4, 5, 8, 16, 32]),
           groups=st.integers(1, 3),
           kernel_h=st.integers(1, 7),
           kernel_w=st.integers(1, 7),
           stride_h=st.integers(1, 2),
           stride_w=st.integers(1, 2),
           pad_h=st.integers(0, 2),
           pad_w=st.integers(0, 2),
           dilation=st.integers(1, 2),
           X_scale=st.floats(1.2, 1.6),
           X_zero_point=st.integers(0, 4),
           W_scale=st.lists(st.floats(0.2, 1.6), min_size=1, max_size=2),
           W_zero_point=st.lists(st.integers(-5, 5), min_size=1, max_size=2),
           Y_scale=st.floats(4.2, 5.6),
           Y_zero_point=st.integers(0, 4),
           use_bias=st.booleans(),
           use_relu=st.sampled_from([False]),
           use_channelwise=st.booleans())
    @override_qengines
    def test_qconv2d(
            self,
            batch_size,
            input_channels_per_group,
            height,
            width,
            output_channels_per_group,
            groups,
            kernel_h,
            kernel_w,
            stride_h,
            stride_w,
            pad_h,
            pad_w,
            dilation,
            X_scale,
            X_zero_point,
            W_scale,
            W_zero_point,
            Y_scale,
            Y_zero_point,
            use_bias,
            use_relu,
            use_channelwise,
    ):
        input_channels = input_channels_per_group * groups
        output_channels = output_channels_per_group * groups
        kernels = (kernel_h, kernel_w)
        strides = (stride_h, stride_w)
        pads = (pad_h, pad_w)
        dilations = (dilation, dilation)

        qconv = torch.ops.quantized.conv2d
        if use_relu:
            qconv = torch.ops.quantized.conv2d_relu
        qconv_prepack = torch.ops.quantized.conv2d_prepack
        conv_op = torch.nn.Conv2d(
            input_channels,
            output_channels,
            kernels,
            strides,
            pads,
            dilations,
            groups,
        )
        self._test_qconv_impl(
            qconv, qconv_prepack, conv_op, batch_size,
            input_channels_per_group, (height, width),
            output_channels_per_group, groups, kernels, strides, pads,
            dilations, X_scale, X_zero_point, W_scale, W_zero_point,
            Y_scale, Y_zero_point, use_bias, use_relu, use_channelwise)

    """Tests the correctness of the quantized::qconv_unpack op."""
    @given(
        inputs=hu.tensor_conv(
            spatial_dim=2, batch_size_range=(1, 3),
            input_channels_per_group_range=(1, 4),
            output_channels_per_group_range=(1, 4), feature_map_range=(4, 8),
            kernel_range=(1, 4), max_groups=4,
            qparams=[hu.qparams(dtypes=torch.quint8,
                                zero_point_min=0,
                                zero_point_max=0),
                     hu.qparams(dtypes=torch.qint8,
                                zero_point_min=0,
                                zero_point_max=0),
                     hu.qparams(dtypes=torch.qint32,
                                zero_point_min=0,
                                zero_point_max=0)]),
        stride_h=st.integers(1, 3), stride_w=st.integers(1, 3),
        pad_h=st.integers(1, 2), pad_w=st.integers(1, 2),
        channelwise=st.booleans())
    @override_qengines
    def test_qconv_unpack(
        self, inputs, stride_h, stride_w, pad_h, pad_w, channelwise
    ):

        qconv_prepack = torch.ops.quantized.conv2d_prepack
        qconv_unpack = torch.ops.quantized.conv2d_unpack
        self._test_qconv_unpack_impl(
            qconv_prepack, qconv_unpack, inputs, (stride_h, stride_w),
            (pad_h, pad_w), channelwise)

    @given(
        inputs=hu.tensor_conv(
            spatial_dim=1, batch_size_range=(1, 3),
            input_channels_per_group_range=(1, 4),
            output_channels_per_group_range=(1, 4), feature_map_range=(4, 8),
            kernel_range=(1, 4), max_groups=4,
            qparams=[hu.qparams(dtypes=torch.quint8,
                                zero_point_min=0,
                                zero_point_max=0),
                     hu.qparams(dtypes=torch.qint8,
                                zero_point_min=0,
                                zero_point_max=0),
                     hu.qparams(dtypes=torch.qint32,
                                zero_point_min=0,
                                zero_point_max=0)]),
        stride=st.integers(1, 3),
        pad=st.integers(1, 2),
        channelwise=st.booleans(),
        qengine=st.sampled_from(("qnnpack", "fbgemm")))
    def test_qconv1d_unpack(
        self, inputs, stride, pad, channelwise, qengine
    ):
        if qengine not in supported_qengines:
            return
        if qengine == 'qnnpack':
            channelwise = False
        with override_quantized_engine(qengine):
            qconv_prepack = torch.ops.quantized.conv1d_prepack
            qconv_unpack = torch.ops.quantized.conv1d_unpack
            self._test_qconv_unpack_impl(
                qconv_prepack, qconv_unpack, inputs, [stride],
                [pad], channelwise)

    """Tests the correctness of quantized 1D convolution op."""
    @given(batch_size=st.integers(1, 6),
           input_channels_per_group=st.sampled_from((2, 4, 5, 8, 16, 32)),
           output_channels_per_group=st.sampled_from((2, 4, 5, 8, 16, 32)),
           groups=st.integers(1, 3),
           length=st.integers(4, 16),
           kernel=st.integers(1, 7),
           stride=st.integers(1, 2),
           pad=st.integers(0, 2),
           dilation=st.integers(1, 2),
           X_scale=st.floats(1.2, 1.6),
           X_zero_point=st.integers(0, 4),
           W_scale=st.lists(st.floats(0.2, 1.6), min_size=1, max_size=2),
           W_zero_point=st.lists(st.integers(-5, 5), min_size=1, max_size=2),
           Y_scale=st.floats(4.2, 5.6),
           Y_zero_point=st.integers(0, 4),
           use_bias=st.booleans(),
           use_relu=st.booleans(),
           use_channelwise=st.booleans())
    @override_qengines
    def test_qconv1d(
        self,
        batch_size,
        input_channels_per_group,
        output_channels_per_group,
        groups,
        length,
        kernel,
        stride,
        pad,
        dilation,
        X_scale,
        X_zero_point,
        W_scale,
        W_zero_point,
        Y_scale,
        Y_zero_point,
        use_bias,
        use_relu,
        use_channelwise,
    ):

        input_channels = input_channels_per_group * groups
        output_channels = output_channels_per_group * groups
        if torch.backends.quantized.engine == 'qnnpack':
            use_channelwise = False
        true_conv1d = torch.nn.Conv1d(
            input_channels,
            output_channels,
            kernel,
            stride,
            pad,
            dilation,
            groups,
        )
        qconv_prepack = torch.ops.quantized.conv1d_prepack
        qconv = torch.ops.quantized.conv1d
        if use_relu:
            qconv = torch.ops.quantized.conv1d_relu
        self._test_qconv_impl(
            qconv, qconv_prepack, true_conv1d, batch_size,
            input_channels_per_group, (length, ),
            output_channels_per_group, groups, kernel, [stride], [pad],
            [dilation], X_scale, X_zero_point, W_scale, W_zero_point,
            Y_scale, Y_zero_point, use_bias, use_relu, use_channelwise
        )

    @given(batch_size=st.integers(1, 4),
           input_channels_per_group=st.sampled_from([2, 4, 5, 8, 16]),
           D=st.integers(4, 8),
           H=st.integers(4, 8),
           W=st.integers(4, 8),
           output_channels_per_group=st.sampled_from([2, 4, 5, 8, 16]),
           groups=st.integers(1, 3),
           kernel_d=st.integers(1, 4),
           kernel_h=st.integers(1, 4),
           kernel_w=st.integers(1, 4),
           stride_d=st.integers(1, 2),
           stride_h=st.integers(1, 2),
           stride_w=st.integers(1, 2),
           pad_d=st.integers(0, 2),
           pad_h=st.integers(0, 2),
           pad_w=st.integers(0, 2),
           dilation=st.integers(1, 2),
           X_scale=st.floats(1.2, 1.6),
           X_zero_point=st.integers(0, 4),
           W_scale=st.lists(st.floats(0.2, 1.6), min_size=1, max_size=2),
           W_zero_point=st.lists(st.integers(-5, 5), min_size=1, max_size=2),
           Y_scale=st.floats(4.2, 5.6),
           Y_zero_point=st.integers(0, 4),
           use_bias=st.booleans(),
           use_relu=st.booleans(),
           use_channelwise=st.booleans(),
           qengine=st.sampled_from(("fbgemm",)))
    def test_qconv3d(
        self,
        batch_size,
        input_channels_per_group,
        D,
        H,
        W,
        output_channels_per_group,
        groups,
        kernel_d,
        kernel_h,
        kernel_w,
        stride_d,
        stride_h,
        stride_w,
        pad_d,
        pad_h,
        pad_w,
        dilation,
        X_scale,
        X_zero_point,
        W_scale,
        W_zero_point,
        Y_scale,
        Y_zero_point,
        use_bias,
        use_relu,
        use_channelwise,
        qengine
    ):
        if qengine not in supported_qengines:
            return

        input_channels = input_channels_per_group * groups
        output_channels = output_channels_per_group * groups
        kernels = (kernel_d, kernel_h, kernel_w)
        strides = (stride_d, stride_h, stride_w)
        pads = (pad_d, pad_h, pad_w)
        dilations = (dilation, dilation, dilation)

        with override_quantized_engine(qengine):
            qconv = torch.ops.quantized.conv3d
            if use_relu:
                qconv = torch.ops.quantized.conv3d_relu
            qconv_prepack = torch.ops.quantized.conv3d_prepack
            conv_op = torch.nn.Conv3d(
                input_channels,
                output_channels,
                kernels,
                strides,
                pads,
                dilations,
                groups,
            )
            self._test_qconv_impl(
                qconv, qconv_prepack, conv_op, batch_size,
                input_channels_per_group, (D, H, W), output_channels_per_group,
                groups, kernels, strides, pads, dilations, X_scale,
                X_zero_point, W_scale, W_zero_point, Y_scale, Y_zero_point,
                use_bias, use_relu, use_channelwise)

    """Tests the correctness of the quantized::qconv3d_unpack op."""
    @given(
        inputs=hu.tensor_conv(
            spatial_dim=3, batch_size_range=(1, 3),
            input_channels_per_group_range=(1, 3),
            output_channels_per_group_range=(1, 3), feature_map_range=(3, 6),
            kernel_range=(1, 3), max_groups=3,
            qparams=[hu.qparams(dtypes=torch.quint8,
                                zero_point_min=0,
                                zero_point_max=0),
                     hu.qparams(dtypes=torch.qint8,
                                zero_point_min=0,
                                zero_point_max=0),
                     hu.qparams(dtypes=torch.qint32,
                                zero_point_min=0,
                                zero_point_max=0)]),
        stride_d=st.integers(1, 2), stride_h=st.integers(1, 2),
        stride_w=st.integers(1, 2),
        pad_d=st.integers(1, 2), pad_h=st.integers(1, 2),
        pad_w=st.integers(1, 2),
        channelwise=st.booleans(),
        qengine=st.sampled_from(("fbgemm",)))
    def test_qconv3d_unpack(
        self, inputs, stride_d, stride_h, stride_w, pad_d, pad_h, pad_w,
        channelwise, qengine
    ):
        if qengine not in supported_qengines:
            return

        with override_quantized_engine(qengine):
            qconv3d_prepack = torch.ops.quantized.conv3d_prepack
            qconv3d_unpack = torch.ops.quantized.conv3d_unpack
            self._test_qconv_unpack_impl(
                qconv3d_prepack, qconv3d_unpack, inputs,
                (stride_d, stride_h, stride_w), (pad_d, pad_h, pad_w),
                channelwise)

class TestPadding(TestCase):
    @given(batch_size=st.integers(1, 64),
           channels=st.integers(1, 64),
           width=st.integers(16, 128),
           qtype=st.sampled_from(hu._ALL_QINT_TYPES))
    def test_reflection_pad1d(self, batch_size, channels, width, qtype):
        padding = width // 4

        x = torch.arange(batch_size * channels * width).to(torch.float)
        x = x.resize(batch_size, channels, width)
        # Per-Tensor test
        scale, zp = _calculate_dynamic_qparams(x, qtype)
        qx = torch.quantize_per_tensor(x, scale, zp, qtype)

        padding_op = torch.nn.ReflectionPad1d(padding)

        y_ref = padding_op(x)
        qy_ref = torch.quantize_per_tensor(y_ref, scale, zp, qtype)
        qy_hat = padding_op(qx)

        self.assertEqual(qy_ref, qy_hat)


@unittest.skipUnless('qnnpack' in supported_qengines,
                     "This Pytorch Build has not been built with or does not support QNNPACK")
class TestQNNPackOps(TestCase):
    """Tests the correctness of the quantized::qnnpack_relu op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams(dtypes=torch.quint8,
                                          zero_point_min=0,
                                          zero_point_max=0)))
    def test_qnnpack_relu(self, X):
        with override_quantized_engine('qnnpack'):
            X, (scale, zero_point, torch_type) = X
            relu = torch.nn.functional.relu
            X = torch.from_numpy(X)
            Y = X.clone()

            qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point, dtype=torch_type)
            qY_hat = relu(qX)

            Y[Y < 0] = 0
            qY = torch.quantize_per_tensor(Y, scale=scale, zero_point=zero_point, dtype=torch_type)
            self.assertEqual(qY, qY_hat)

    """Tests the correctness of the quantized::qnnpack_tanh op."""
    @skipIfNoFBGEMM
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams(dtypes=torch.quint8)))
    def test_qnnpack_tanh(self, X):
        # Note: In QNNPACK the output scale and zero_point can only be
        #       2.0/256, 128 respectively, as it uses a LUT with 256 bins.
        X, (scale, zero_point, torch_type) = X
        X = torch.from_numpy(X)
        qX = torch.quantize_per_tensor(X, scale=scale,
                                       zero_point=zero_point,
                                       dtype=torch_type)

        # Floating point reference
        Y = torch.tanh(X)
        qY = torch.quantize_per_tensor(Y, scale=1.0 / 128, zero_point=128,
                                       dtype=torch.quint8)
        with override_quantized_engine('fbgemm'):
            qYserver = torch.tanh(qX)
        with override_quantized_engine('qnnpack'):
            qY_hat = torch.tanh(qX)
            self.assertEqual(qY, qY_hat,
                             msg="QNNPACK TanH failed (FP ref)!")
            self.assertEqual(qYserver, qY_hat,
                             msg="QNNPACK TanH failed (FBGEMM ref)!")

    """Tests the correctness of the quantized::qnnpack_sigmoid op."""
    @skipIfNoFBGEMM
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams(dtypes=torch.quint8)))
    def test_qnnpack_sigmoid(self, X):
        # Note: In QNNPACK the output scale and zero_point can only be
        #       1.0/256, 0 respectively, as it uses a LUT with 256 bins.
        X, (scale, zero_point, torch_type) = X
        X = torch.from_numpy(X).to(torch.float32)
        qX = torch.quantize_per_tensor(X, scale=scale,
                                       zero_point=zero_point,
                                       dtype=torch_type)

        # Floating point reference
        Y = torch.sigmoid(X)
        qY = torch.quantize_per_tensor(Y, scale=1.0 / 256, zero_point=0,
                                       dtype=torch.quint8)
        with override_quantized_engine('fbgemm'):
            qYserver = torch.sigmoid(qX)
        with override_quantized_engine('qnnpack'):
            qY_hat = torch.sigmoid(qX)
            self.assertEqual(qY, qY_hat,
                             msg="QNNPACK Sigmoid failed (FP ref)!")
            self.assertEqual(qYserver, qY_hat,
                             msg="QNNPACK Sigmoid failed (FBGEMM ref)!")

    @skipIfNoFBGEMM
    def test_qnnpack_sigmoid_sweep(self):
        # Input parameters
        f_min = -4.0
        f_max = 4.0
        scale = (f_max - f_min) / 256.0
        zero_point = 128
        dtype = torch.quint8

        step = scale / 2.0
        x = np.arange(f_min, f_max + step, step)
        X = torch.from_numpy(x).to(torch.float32)
        qX = torch.quantize_per_tensor(X, scale=scale,
                                       zero_point=zero_point,
                                       dtype=dtype)

        dqX = qX.dequantize()
        # Floating point reference
        Y = torch.sigmoid(dqX)
        qY = torch.quantize_per_tensor(Y, scale=1.0 / 256, zero_point=0,
                                       dtype=torch.quint8)
        with override_quantized_engine('fbgemm'):
            qYserver = torch.sigmoid(qX)
        with override_quantized_engine('qnnpack'):
            qY_hat = torch.sigmoid(qX)
            self.assertEqual(qY, qY_hat,
                             msg="QNNPACK Sigmoid failed (FP ref)!")
            self.assertEqual(qYserver, qY_hat,
                             msg="QNNPACK Sigmoid failed (FBGEMM ref)!")

    """Tests the correctness of the quantized::add (qnnpack) op."""
    @settings(suppress_health_check=(HealthCheck.filter_too_much,))
    @given(A=hu.tensor(shapes=hu.array_shapes(1, 5, 1, 5),
                       qparams=hu.qparams(dtypes=torch.quint8)),
           zero_point=st.sampled_from([0, 2, 5, 15, 127]),
           scale_A=st.sampled_from([0.001, 0.057, 0.889, 12.3]),
           scale_B=st.sampled_from([0.008, 0.0821, 0.67, 7]),
           scale_C=st.sampled_from([0.003, 0.07821, 0.457, 7.34]),)
    def test_qnnpack_add(self, A, zero_point, scale_A, scale_B, scale_C):
        with override_quantized_engine('qnnpack'):
            A_temp = A
            A, (scale_a, zero_point_A, torch_type) = A_temp
            B, (scale_b, zero_point_B, torch_type) = A_temp
            A = torch.from_numpy(A)
            B = torch.from_numpy(B)

            assume(scale_A // scale_C >= 2**-14)
            assume(scale_A // scale_C < 2**8)
            assume(scale_B // scale_C >= 2**-14)
            assume(scale_B // scale_C < 2**8)

            zero_point_C = 127
            qA = torch.quantize_per_tensor(A, scale=scale_A, zero_point=zero_point,
                                           dtype=torch.quint8)
            qB = torch.quantize_per_tensor(B, scale=scale_B, zero_point=zero_point,
                                           dtype=torch.quint8)

            # Add ground truth
            C = (qA.dequantize() + qB.dequantize()).numpy()

            qC = _quantize(C, scale_C, zero_point_C)

            qC_qnnp = torch.ops.quantized.add(qA, qB, scale_C, zero_point_C)

            np.testing.assert_equal(qC, qC_qnnp.int_repr(),
                                    "Quantized addition failed.")

            Crelu = C.copy()
            Crelu[C < 0] = 0
            qCrelu = torch.quantize_per_tensor(torch.from_numpy(Crelu), scale_C,
                                               zero_point_C, dtype=torch.quint8)
            qCrelu_hat = torch.ops.quantized.add_relu(qA, qB, scale=scale_C, zero_point=zero_point_C)
            np.testing.assert_equal(qCrelu.int_repr().numpy(), qCrelu_hat.int_repr(),
                                    "Quantized addition with ReLU failed.")

    """Tests the correctness of quantized::qnnpack_maxpool2d op."""
    @given(A=hu.tensor(shapes=hu.array_shapes(4, 4, 3, 5),
                       qparams=hu.qparams(dtypes=torch.quint8)),
           kernel=st.sampled_from([2, 4]),
           stride=st.sampled_from([1, 2]),
           padding=st.sampled_from([1, 2]))
    def test_qnnpack_maxpool2d(self, A, kernel, stride, padding):
        import torch.nn.functional as F

        with override_quantized_engine('qnnpack'):
            A, (scale, zero_point, torch_type) = A
            X = torch.from_numpy(A)
            np_type = np.uint8
            dilation = 1

            # Check constraints
            assume(kernel // 2 >= padding)  # Kernel cannot be overhanging!

            iH, iW = X.shape[-2:]

            oH = pool_output_shape(iH, kernel, padding, stride, dilation)
            assume(oH > 0)
            oW = pool_output_shape(iW, kernel, padding, stride, dilation)
            assume(oW > 0)

            k = (kernel, kernel)
            s = (stride, stride)
            d = (dilation, dilation)
            p = (padding, padding)

            q_max_pool = torch.ops.quantized.max_pool2d

            a = scale * (X - zero_point).to(dtype=torch.float)
            qa = torch.quantize_per_tensor(a, scale=scale, zero_point=zero_point,
                                           dtype=torch_type)

            a_ref = qa.dequantize()

            a_pool = F.max_pool2d(a_ref, kernel_size=k, stride=s, padding=p,
                                  dilation=d)

            a_pool_nhwc = a_pool.permute([0, 2, 3, 1])

            qa_pool = q_max_pool(qa, k, s, p, d, ceil_mode=False)

            qa_pool_int = qa_pool.dequantize()
            np.testing.assert_equal(a_pool.numpy(), qa_pool_int.numpy())

    @given(batch_size=st.integers(1, 5),
           channels=st.sampled_from([2, 4, 5, 8, 16, 32]),
           height=st.integers(4, 10),
           width=st.integers(4, 10),
           kernel=st.integers(2, 5),
           stride=st.integers(1, 2),
           padding=st.integers(1, 2),
           scale=st.floats(0.2, 1.6),
           zero_point=st.integers(0, 25)
           )
    def test_avg_pool2d(
            self,
            batch_size,
            channels,
            height,
            width,
            kernel,
            stride,
            padding,
            scale,
            zero_point

    ):
        with override_quantized_engine('qnnpack'):
            import torch.nn.functional as F
            X_init = torch.from_numpy(np.random.randint(
                0, 50, (batch_size, channels, height, width)))

            X = scale * (X_init - zero_point).to(dtype=torch.float)

            # Check constraints
            assume(kernel // 2 >= padding)  # Kernel cannot be overhanging!

            iH, iW = X.shape[-2:]

            oH = pool_output_shape(iH, kernel, padding, stride, 1)
            assume(oH > 0)
            oW = pool_output_shape(iW, kernel, padding, stride, 1)
            assume(oW > 0)
            k = (kernel, kernel)
            s = (stride, stride)
            p = (padding, padding)

            q_avg_pool = torch.nn.quantized.functional.avg_pool2d

            x_q = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                            dtype=torch.quint8)

            a_pool = F.avg_pool2d(x_q.dequantize().to(torch.float), kernel_size=k, stride=s, padding=p)
            qa_pool = q_avg_pool(x_q, k, s, p)
            # Quantize Ref Output
            a_pool_q = torch.quantize_per_tensor(a_pool, scale=scale, zero_point=zero_point,
                                                 dtype=torch.quint8)
            np.testing.assert_array_almost_equal(a_pool_q.int_repr().numpy(),
                                                 qa_pool.int_repr().numpy(), decimal=0)


    @given(batch_size=st.integers(1, 5),
           channels=st.sampled_from([2, 4, 5, 8, 16, 32]),
           height=st.integers(4, 20),
           width=st.integers(4, 20),
           output_height=st.integers(2, 10),
           output_width=st.integers(2, 10),
           scale=st.floats(0.2, 1.6),
           zero_point=st.integers(0, 25)
           )
    def test_adaptive_avg_pool2d(
            self,
            batch_size,
            channels,
            height,
            width,
            output_height,
            output_width,
            scale,
            zero_point

    ):
        with override_quantized_engine('qnnpack'):
            # Check constraints
            assume(height >= output_height)
            assume(width >= output_width)

            import torch.nn.functional as F
            X_init = torch.from_numpy(np.random.randint(
                0, 50, (batch_size, channels, height, width)))

            X = scale * (X_init - zero_point).to(dtype=torch.float)

            iH, iW = X.shape[-2:]

            q_avg_pool = torch.nn.quantized.functional.adaptive_avg_pool2d

            x_q = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                            dtype=torch.quint8)

            a_pool = F.adaptive_avg_pool2d(x_q.dequantize().to(torch.float), (output_height, output_width))
            qa_pool = q_avg_pool(x_q, (output_height, output_width))
            # Quantize Ref Output
            a_pool_q = torch.quantize_per_tensor(a_pool, scale=scale, zero_point=zero_point,
                                                 dtype=torch.quint8)
            np.testing.assert_array_almost_equal(a_pool_q.int_repr().numpy(),
                                                 qa_pool.int_repr().numpy(), decimal=0)


    @given(batch_size=st.integers(1, 5),
           channels=st.sampled_from([2, 4, 5, 8, 16, 32]),
           height=st.integers(4, 10),
           width=st.integers(4, 10),
           scale=st.floats(0.02, 2.6),
           zero_point=st.integers(0, 25))
    def test_mean(self, batch_size, channels, height, width, scale, zero_point):
        with override_quantized_engine('qnnpack'):
            dim = (2, 3)
            X_init = torch.from_numpy(np.random.randint(
                0, 50, (batch_size, channels, height, width)))
            X = scale * (X_init - zero_point).to(dtype=torch.float)

            qX = torch.quantize_per_tensor(X, scale, zero_point, torch.quint8)
            Y = torch.mean(qX.dequantize(), dim)
            Y = torch.quantize_per_tensor(Y, scale, zero_point, torch.quint8)
            qY = torch.mean(qX, dim)
            np.testing.assert_array_almost_equal(Y.int_repr().numpy(), qY.int_repr().numpy(), decimal=0)

    """Tests the correctness of the quantized::hardtanh op."""
    @given(X=hu.tensor(shapes=hu.array_shapes(1, 8, 1, 8, max_numel=10**5),
                       elements=hu.floats(-1e6, 1e6, allow_nan=False, allow_infinity=False),
                       qparams=hu.qparams(dtypes=torch.quint8)),
           min_val=hu.floats(-1e6, -9.999999974752427e-07, allow_nan=False, allow_infinity=False),
           max_val=hu.floats(9.999999974752427e-07, 1e6, allow_nan=False, allow_infinity=False))
    def test_hardtanh(self, X, min_val, max_val):
        if 'qnnpack' not in torch.backends.quantized.supported_engines:
            return
        with override_quantized_engine('qnnpack'):
            X, (scale, zero_point, torch_type) = X

            assume(min_val <= max_val)
            Y = X.copy()
            Y[Y < min_val] = min_val
            Y[Y > max_val] = max_val
            qY = torch.quantize_per_tensor(torch.from_numpy(Y), scale=scale,
                                           zero_point=zero_point, dtype=torch_type)
            X = torch.from_numpy(X)
            qX = torch.quantize_per_tensor(X, scale=scale, zero_point=zero_point,
                                           dtype=torch_type)

            qY_hat = torch.nn.quantized.functional.hardtanh(qX, min_val, max_val)
            self.assertEqual(
                qY, qY_hat,
                msg="hardtanh failed:\nactual {}\nexpected {}".format(qY_hat, qY))

"""Tests the correctness of the tensor comparators."""
class TestComparatorOps(TestCase):
    """Tests the element-wise equality ops."""
    @given(A=hu.tensor(shapes=((3, 4, 5),),
                       qparams=hu.qparams()),
           B=hu.tensor(shapes=((5,), (1, 5), (1, 1, 5), (4, 5), (3, 4, 5)),
                       qparams=hu.qparams()))
    def test_compare_tensor_tensor(self, A, B):
        A, (scale_a, zero_point_a, dtype_a) = A
        B, (scale_b, zero_point_b, dtype_b) = B
        tA = torch.from_numpy(A)
        tB = torch.from_numpy(B)

        qA = torch.quantize_per_tensor(tA, scale=scale_a, zero_point=zero_point_a,
                                       dtype=dtype_a)
        qB = torch.quantize_per_tensor(tB, scale=scale_b, zero_point=zero_point_b,
                                       dtype=dtype_b)
        dqA = qA.dequantize()
        dqB = qB.dequantize()

        ops_under_test = ('__eq__', '__ne__', '__ge__', '__le__', '__gt__',
                          '__lt__', 'eq', 'ne', 'ge', 'le', 'gt', 'lt')

        for op in ops_under_test:
            result_ref = getattr(dqA, op)(dqB)
            result = getattr(qA, op)(qB)
            self.assertEqual(result_ref, result,
                             msg="'tensor.{}(tensor)'' failed".format(op))
            # Reversed broadcasting.
            result_ref = getattr(dqB, op)(dqA)
            result = getattr(qB, op)(qA)
            self.assertEqual(result_ref, result,
                             msg="'tensor.{}(tensor)'' failed".format(op))

    @given(A=hu.tensor(shapes=((3, 4, 5),),
                       qparams=hu.qparams()),
           b=hu.floats(allow_infinity=False, allow_nan=False))
    def test_compare_tensor_scalar(self, A, b):
        A, (scale_a, zero_point_a, dtype_a) = A
        tA = torch.from_numpy(A)

        qA = torch.quantize_per_tensor(tA, scale=scale_a, zero_point=zero_point_a,
                                       dtype=dtype_a)
        dqA = qA.dequantize()

        ops_under_test_reversible = ('__eq__', '__ne__', '__ge__', '__le__',
                                     '__gt__', '__lt__')
        ops_under_test_nonreversible = ('eq', 'ne', 'ge', 'le', 'gt', 'lt')

        for op in ops_under_test_reversible:
            result_ref = getattr(dqA, op)(b)
            result = getattr(qA, op)(b)
            note("result_ref 1: {}".format(result_ref))
            note("result 1: {}".format(result))
            self.assertEqual(result_ref, result,
                             msg="'tensor.{}(scalar)'' failed".format(op))
            # Reversed broadcasting.
            result_ref = getattr(b, op)(dqA)
            result = getattr(b, op)(qA)
            note("result_ref 2: {}".format(result_ref))
            note("result 2: {}".format(result))
            self.assertEqual(result_ref, result,
                             msg="'scalar.{}(tensor)'' failed".format(op))

        for op in ops_under_test_nonreversible:
            result_ref = getattr(dqA, op)(b)
            result = getattr(qA, op)(b)
            note("result_ref 3: {}".format(result_ref))
            note("result 3: {}".format(result))
            self.assertEqual(result_ref, result,
                             msg="'tensor.{}(scalar)'' failed".format(op))
