utility.py 31.7 KB
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#   Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
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from paddle.fluid import core
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import numpy as np
import math
import os
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from paddle.fluid.executor import global_scope
from paddle.fluid import io

__all__ = ['Calibrator']
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class Calibrator(object):
    '''
    The calibrator class transforms the program and updates the calculated scale into it.
    This is INT8 v1 calibration tool, mainly for the support of ResNet-50 and MobileNet.
    '''
    # TODO(guomingz): Below op list will be updated once more INT8 op kernels are supported.
    non_conv_int8_op_type = ("pool2d")
    supported_int8_op_type = ("conv2d", "pool2d")
    const_sign_op_type = ('pool2d', 'reshape', 'concat', 'transpose')
    u8_max = 255
    s8_max = 127

    def __init__(self, *args, **kwargs):
        self.program = kwargs['program']
        self.pretrained_model = kwargs['pretrained_model']
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        self.debug = kwargs['debug'] if 'debug' in kwargs else False
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        self.algo = kwargs['algo']
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        self.output = kwargs['output']
        self.feed_var_names = kwargs['feed_var_names']
        self.fetch_list = kwargs['fetch_list']
        self.exe = kwargs['exe']
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        self._conv_input_var_name = []
        self._conv_output_var_name = []
        self._pool2d_output_var_name = []
        self._weights_var_name = []
        self._residual_input_var_name = []
        self._int8_output_var_op_index_dict = {}
        self._conv_op_index = [
            index for index, value in enumerate(self.program.global_block().ops)
            if value.type == 'conv2d'
        ]

        self._var_max_value_map = {}
        self._var_max_range = {}
        self._weights_scaling_factor = {}
        self._u8_output_var = []
        self._s8_output_var = []
        self._persistable_vars = []
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        self._sampling_data = {}
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        self.__init_analysis()
        self.__generate_output_program()

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    def save_int8_model(self):
        self.__sampling(self._sampling_data)
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        self.__save_scale()
        self.__update_program()
        self.__update_output_program_attr()
        self.__display_debug()
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        self.__save_offline_model()

    def sample_data(self):
        '''
        Sampling the tensor data of variable.
        '''
        for i in self.sampling_program.list_vars():
            if i.name in self.sampling_vars:
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                np_data = np.array(global_scope().find_var(i.name).get_tensor())
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                if i.name not in self._sampling_data:
                    self._sampling_data[i.name] = []
                self._sampling_data[i.name].append(np_data)

    def __save_offline_model(self):
        '''
        Save the quantized model to the disk.
        '''
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        io.save_inference_model(self.output, self.feed_var_names,
                                self.fetch_list, self.exe,
                                self.sampling_program)
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    def __display_debug(self):
        if self.debug:
            self.__dot(self._output_program)
            print(self._output_program)

    def __get_max_range_by_var_name(self, program, var_name):
        """
        Check the specified variable was generated from Relu layer or not.
        If the variable was the output of one of the pool2d/reshape/concat
        /transpose, we keep trace the ancestor of this variable;
        If the variable was the output the conv op, we check it's has_relu
        attr;
        Otherwise, we return the Calibrator.s8 as default value.
        Returns:
            Return Calibrator.u8_max if the variable was generated by Relu,
            otherwise it will returns Calibrator.s8
        """
        search_end_index = -1
        input_index_name = {}
        output_index_name = {}
        ops_type = []

        for index, op in enumerate(program.current_block().ops):
            ops_type.append(op.type)

            input_index_name[index] = op.input_arg_names

            output_index_name[index] = op.output_arg_names
            if var_name in op.output_arg_names:
                search_end_index = index

        # analysis
        while search_end_index >= 0:
            if ops_type[search_end_index] == "relu":
                return Calibrator.u8_max

            input_name = input_index_name[search_end_index][0]

            for i in output_index_name.keys():
                if input_name in output_index_name[i]:
                    search_end_index = i
                    break

            if ops_type[
                    search_end_index] not in Calibrator.const_sign_op_type and ops_type[
                        search_end_index] != 'conv2d':
                return Calibrator.s8_max

            if ops_type[search_end_index] != 'conv2d':
                continue

            if program.current_block().ops[search_end_index].has_attr(
                    'fuse_relu') and program.current_block().ops[
                        search_end_index].attr('fuse_relu'):
                return Calibrator.u8_max
            else:
                return Calibrator.s8_max

        return Calibrator.s8_max

    def __check_op_type_with_specified_var_as_input(self,
                                                    program,
                                                    var_name,
                                                    start_index=0):
        '''
        Check whether all the type of ops that use the specified variable as the
        input.If one of those op is not int8-enabled, return False.
        '''
        op_type_list = [
            op.type for op in program.current_block().ops[start_index:]
            if var_name in op.input_arg_names
        ]
        for i in op_type_list:
            if not i in Calibrator.supported_int8_op_type:
                return False
        return True

    def __check_var_source_dt(self, var_name):
        '''
        Check whether the specified variable is the output of int8 conv op or not.
        If true, return the original op index.
        If false, return -1
        '''
        return self._int8_output_var_op_index_dict[
            var_name] if var_name in self._int8_output_var_op_index_dict else -1

    def __update_int8_output_var_op_index_dict(self, index, var_name=None):
        '''
        Update the int8_output_variable/op_index dictionary
        '''
        for k, v in self._int8_output_var_op_index_dict.items():
            if v >= index:
                self._int8_output_var_op_index_dict[k] = v + 1
        if var_name:
            self._int8_output_var_op_index_dict[var_name] = index

    def __update_program(self):
        '''
        Update the program with the quantize/dequantize op insertion.
        '''
        quantize_index, dequantize_index = self.__get_quantize_dequantize_combination(
            self._output_program)
        inserted_op_length = 0
        calc_max_func = self.__get_optimal_scaling_factor if self.algo == "KL" else np.max
        insert_op_collection = sorted(quantize_index + dequantize_index)

        for index in insert_op_collection:
            if index in quantize_index:
                quantize_tmp = self._output_program.current_block().create_var(
                    name="quantize_{}_tmp".format(index),
                    dtype=core.VarDesc.VarType.UINT8)
                original_out_name = self._output_program.current_block().ops[
                    index + inserted_op_length - 1].output_names[0]
                original_out = self._output_program.current_block().ops[
                    index + inserted_op_length - 1].output(original_out_name)[0]

                op = self._output_program.current_block()._insert_op(
                    index=index + inserted_op_length,
                    type="quantize",
                    inputs={"Input": original_out},
                    outputs={"Output": quantize_tmp}, )

                op._set_attr("data_format", "MKLDNNLAYOUT")
                op._set_attr("use_mkldnn", 1)
                op._set_attr(
                    "Scale", self._var_max_range[original_out] /
                    calc_max_func(self._var_max_value_map[original_out]))

                if self.__get_max_range_by_var_name(
                        self._output_program,
                        original_out) == Calibrator.s8_max:
                    op._set_attr("is_negative_input", 1)

                self.__update_int8_output_var_op_index_dict(
                    index + inserted_op_length, "quantize_{}_tmp".format(index))

                inserted_op_length += 1
                for op in self._output_program.current_block().ops[
                        index + inserted_op_length:]:
                    for j in op.input_names:
                        if op.input(j) and op.input(
                                j
                        )[0] == original_out and op.type in Calibrator.supported_int8_op_type:
                            op.desc.set_input(j,
                                              ["{}".format(quantize_tmp.name)])
            else:
                start_index = index + inserted_op_length
                dequantize_tmp_var = self._output_program.current_block(
                ).create_var(
                    name="dequantize_{}_tmp".format(index + 1),
                    dtype="float32", )
                original_out_var = None

                for original_input in self._output_program.current_block().ops[
                        start_index].input_arg_names:
                    index_res = self.__get_op_index_by_output_var(
                        self._output_program, original_input)
                    if index_res != -1:
                        original_out_var = original_input
                        break

                if original_out_var:
                    op = self._output_program.current_block()._insert_op(
                        index=start_index,
                        type="dequantize",
                        inputs={"Input": original_out_var},
                        outputs={"Output": dequantize_tmp_var})
                    op._set_attr("data_format", "MKLDNNLAYOUT")
                    op._set_attr("use_mkldnn", 1)
                    op._set_attr("Scale", self._var_max_range[original_out_var]
                                 / calc_max_func(self._var_max_value_map[
                                     original_out_var]))

                    for op_index in range(
                            start_index + 1,
                            len(self._output_program.current_block().ops)):
                        if self._output_program.current_block(
                        ).ops[op_index].type == "conv2d" and self._output_program.current_block(
                        ).ops[op_index].attr("force_fp32_output"):
                            continue
                        else:
                            for j in self._output_program.current_block().ops[
                                    op_index].input_names:
                                if len(self._output_program.current_block().ops[
                                        op_index].input(j)
                                       ) and self._output_program.current_block(
                                       ).ops[op_index].input(j)[
                                           0] == original_out_var:
                                    self._output_program.current_block(
                                    ).ops[op_index].desc.set_input(
                                        j,
                                        ["{}".format(dequantize_tmp_var.name)])

                    inserted_op_length += 1

                    op._set_attr("data_format", "MKLDNNLAYOUT")
                    op._set_attr("use_mkldnn", 1)

    def __update_output_program_attr(self):
        for i in self._output_program.list_vars():
            if i.name in self._persistable_vars:
                i.persistable = False
                os.system("rm -rf {}/{}".format(self.pretrained_model, i.name))

        for i in self._u8_output_var:
            self._output_program.current_block().var(i).desc.set_dtype(
                core.VarDesc.VarType.UINT8)

        for i in self._s8_output_var:
            self._output_program.current_block().var(i).desc.set_dtype(
                core.VarDesc.VarType.INT8)

    @property
    def sampling_program(self):
        return self._output_program

    @property
    def sampling_vars(self):
        return self._weights_var_name + self._conv_input_var_name + self._conv_output_var_name + self._residual_input_var_name + self._pool2d_output_var_name

    def _is_close(self, a, b, rel_tol=1e-09, abs_tol=0.0):
        return abs(a - b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)

    def __generate_output_program(self):
        for i in self.program.list_vars():
            if not i.persistable and i.name in self.sampling_vars:
                i.persistable = True
                self._persistable_vars.append(i.name)

        self._output_program = self.program.clone()

    def __save_scale(self):
        '''
        Update the convolution scale information.
        '''
        func = self.__get_optimal_scaling_factor if self.algo == 'KL' else np.max
        for i in self._conv_op_index[1:]:
            weights_var_name = self.program.current_block().ops[i].input(
                'Filter')[0]
            input_var_name = self.program.current_block().ops[i].input('Input')[
                0]
            output_var_name = self.program.current_block().ops[i].output(
                'Output')[0]
            self._output_program.current_block().ops[i]._set_attr(
                "Scale_weights", self._weights_scaling_factor[weights_var_name])

            self._output_program.current_block().ops[i]._set_attr(
                "Scale_in", self._var_max_range[input_var_name] /
                func(self._var_max_value_map[input_var_name]))
            self._output_program.current_block().ops[i]._set_attr(
                "Scale_out", self._var_max_range[output_var_name] /
                func(self._var_max_value_map[output_var_name]))
            if self._output_program.current_block().ops[i].desc.input(
                    "ResidualData"):
                residual_var_name = self._output_program.current_block().ops[
                    i].desc.input("ResidualData")[0]
                self._output_program.current_block().ops[i]._set_attr(
                    "Scale_in_eltwise", self._var_max_range[residual_var_name] /
                    func(self._var_max_value_map[residual_var_name]))

    def __sampling(self, sampling_data):
        '''
        Sampling the variables data range.
        '''
        for i in self.program.list_vars():
            if i.name not in self.sampling_vars:
                continue

            if i.name in self._weights_var_name:
                scaling_factor_per_channel = []
                data = sampling_data[i.name][0]
                for j in range(data.shape[0]):
                    var_value = float(np.max(np.abs(data[j])))
                    if not self._is_close(var_value, 0.0):
                        scaling_factor_per_channel.append(Calibrator.s8_max /
                                                          var_value)
                    else:
                        scaling_factor_per_channel.append(0.0)
                self._weights_scaling_factor[
                    i.name] = scaling_factor_per_channel
            else:
                if i.name in self._conv_output_var_name:
                    op_pos = self.__get_op_index_by_output_var(self.program,
                                                               i.name)
                    cur_op = self.program.current_block().ops[op_pos]

                    if cur_op.has_attr('fuse_relu') and cur_op.attr(
                            'fuse_relu'):
                        max_range = Calibrator.u8_max
                        self._u8_output_var.append(i.name)
                    else:
                        max_range = Calibrator.s8_max
                        self._s8_output_var.append(i.name)
                else:
                    max_range = self.__get_max_range_by_var_name(self.program,
                                                                 i.name)
                max_value = [[np.abs(np_data)]
                             for np_data in sampling_data[i.name]]

                self._var_max_range[i.name] = max_range
                self._var_max_value_map[i.name] = max_value

    def __check_force_fp32_attr_by_output_var(self, program, var_name):
        for op in program.current_block().ops:
            if op.type == "conv2d" and var_name in op.output_arg_names:
                return op.attr("force_fp32_output")
        return False

    def __get_op_index_by_output_var(self, program, var_name, start_index=0):
        '''
        Check whether the specified input variable is the output of the
        conv/pool2d op's output or not.

        Returns:
            The index if the variable is the output of any conv/pool2d op's
            output.
            -1 when the variable is not the output of any conv/pool2d op's 
            output.
        '''
        for index, op in enumerate(program.current_block().ops[start_index:]):
            if var_name in op.output_arg_names and op.type in Calibrator.supported_int8_op_type:
                return index
        return -1

    def __get_op_index_by_input_var(self, program, var_name, start_index=0):
        '''
        Get the op index by specified input variable.
        Returns:
            The op index if the variable is the input of this op or -1 if the 
            variable is not the input of any op. 
        '''
        for index, op in enumerate(program.current_block().ops[start_index:]):
            if var_name in op.input_arg_names:
                return index

        return -1

    def __get_quantize_dequantize_combination(self, program):
        """
        Get the quantize/dequantize op index for further inserting.
        Args:
            The program desc.
        Returns:
            Two lists contains the quantize op and dequantize op index information.
        """
        quantize_op_index = []
        dequantize_op_index = []
        minimal_conv_count = 2  # there must be two conv ops if not enable the first conv int8.
        if len(self._conv_op_index) < minimal_conv_count:
            return [], []

        for index, value in enumerate(self._conv_op_index):
            if index == 0:
                quantize_op_index.append(self._conv_op_index[index + 1])
            elif index == len(self._conv_op_index) - 1:
                output_var = program.current_block().ops[value].output(
                    "Output")[0]
                if self.__check_op_type_with_specified_var_as_input(
                        program, output_var, index):
                    dequantize_op_index.append(self._conv_op_index[index] + 2)
                else:
                    program.current_block().ops[value]._set_attr(
                        "force_fp32_output", True)

            elif self._conv_op_index[index] + 1 < self._conv_op_index[index +
                                                                      1]:

                program.current_block().ops[self._conv_op_index[
                    index]]._set_attr("force_fp32_output", True)

                for op_index in range(self._conv_op_index[index + 1],
                                      self._conv_op_index[index], -1):
                    op_type = program.current_block().ops[op_index].type
                    op_has_int8_input = False
                    input_var_name = None
                    input_length = len(program.current_block().ops[op_index]
                                       .input_arg_names)

                    for var_name in program.current_block().ops[
                            op_index].input_arg_names:
                        if self.__check_var_source_dt(var_name) != -1:
                            op_has_int8_input = True
                            input_var_name = var_name
                            break

                    if op_has_int8_input:
                        if op_type == "conv2d":
                            if program.current_block().ops[op_index +
                                                           1].type == "conv2d":
                                continue
                            elif program.current_block(
                            ).ops[op_index +
                                  1].type in Calibrator.non_conv_int8_op_type:
                                dequantize_op_index.append(op_index + 2)
                                break
                            else:
                                program.current_block().ops[op_index]._set_attr(
                                    "force_fp32_output", True)
                                continue
                        elif not self.__check_force_fp32_attr_by_output_var(
                                program, input_var_name
                        ) and op_index not in dequantize_op_index:
                            share_input_flag = True
                            for input_attr_name in program.current_block().ops[
                                    op_index].input_names:
                                input_var_name = program.current_block().ops[
                                    op_index].input(input_attr_name)[0]
                                cousin_op_index = self.__get_op_index_by_input_var(
                                    program, input_var_name)
                                if cousin_op_index != -1 and cousin_op_index in dequantize_op_index:
                                    share_input_flag = False
                                    break
                            if share_input_flag:
                                dequantize_op_index.append(op_index)

                    elif input_length:
                        output_is_to_int8_op = False
                        share_input_flag = True
                        for var_name in program.current_block().ops[
                                op_index].input_arg_names:
                            if not self.__check_op_type_with_specified_var_as_input(
                                    program, var_name):
                                share_input_flag = False
                                break

                        for var_name in program.current_block().ops[
                                op_index].output_arg_names:
                            if self.__get_op_index_by_output_var(
                                    program, var_name, op_index) != -1:
                                output_is_to_int8_op = True
                                break

                        if share_input_flag or output_is_to_int8_op:
                            quantize_op_index.append(op_index)

        return quantize_op_index, dequantize_op_index

    def __init_analysis(self):
        '''
        Collect the variable names for sampling.
        '''
        start_index = 1  #analysis the conv op detail from second conv op.

        for i in self._conv_op_index[start_index:]:
            self._weights_var_name.append(self.program.current_block().ops[i]
                                          .input('Filter')[0])
            self._conv_input_var_name.append(self.program.current_block().ops[i]
                                             .input('Input')[0])
            self._conv_output_var_name.append(self.program.current_block().ops[
                i].output('Output')[0])
            self._int8_output_var_op_index_dict[self.program.current_block()
                                                .ops[i].output('Output')[0]] = i
            if self.program.current_block().ops[i].desc.input("ResidualData"):
                self._residual_input_var_name.append(self.program.current_block(
                ).ops[i].desc.input("ResidualData")[0])

            if self.program.current_block().ops[i + 1].type == "pool2d":
                self._pool2d_output_var_name.append(self.program.current_block(
                ).ops[i + 1].output('Out')[0])

    def __expand_quantized_bins(self, quantized_bins, reference_bins):
        expanded_quantized_bins = [0] * len(reference_bins)
        num_merged_bins = len(reference_bins) / len(quantized_bins)
        j_start = 0
        j_end = num_merged_bins
        for idx in xrange(len(quantized_bins)):
            zero_count = reference_bins[j_start:j_end].count(0)
            num_merged_bins = j_end - j_start
            if zero_count == num_merged_bins:
                avg_bin_ele = 0
            else:
                avg_bin_ele = quantized_bins[idx] / (
                    num_merged_bins - zero_count + 0.0)
            for idx1 in xrange(j_start, j_end):
                expanded_quantized_bins[idx1] = (0 if reference_bins[idx1] == 0
                                                 else avg_bin_ele)
            j_start += num_merged_bins
            j_end += num_merged_bins
            if (idx + 1) == len(quantized_bins) - 1:
                j_end = len(reference_bins)
        return expanded_quantized_bins

    def __safe_entropy(self, reference_distr_P, P_sum, candidate_distr_Q,
                       Q_sum):
        '''
        Calculate the entropy.
        '''
        assert len(reference_distr_P) == len(candidate_distr_Q)
        tmp_sum1 = 0
        tmp_sum2 = 0
        for idx in range(len(reference_distr_P)):
            p_idx = reference_distr_P[idx]
            q_idx = candidate_distr_Q[idx]
            if p_idx == 0:
                tmp_sum1 += 0
                tmp_sum2 += 0
            else:
                if q_idx == 0:
                    print("Fatal error!, idx = " + str(idx) +
                          " qindex = 0! p_idx = " + str(p_idx))
                tmp_sum1 += p_idx * (math.log(Q_sum * p_idx))
                tmp_sum2 += p_idx * (math.log(P_sum * q_idx))
        return (tmp_sum1 - tmp_sum2) / P_sum

    # Reference: http://on-demand.gputechconf.com/gtc/2017/presentation/s7310-8-bit-inference-with-tensorrt.pdf
    def __get_optimal_scaling_factor(self,
                                     activation_blob,
                                     num_quantized_bins=255):
        '''
        Using the KL-divergenc method to get the more precise scaling factor.
        '''
        max_val = np.max(activation_blob)
        min_val = np.min(activation_blob)
        if min_val >= 0:
            hist, hist_edeges = np.histogram(
                activation_blob, bins=2048, range=(min_val, max_val))
            ending_iter = 2047
            starting_iter = int(ending_iter * 0.7)
        else:
            th = max(abs(max_val), abs(min_val))
            hist, hist_edeges = np.histogram(
                activation_blob, bins=2048, range=(-th, th))
            starting_iter = 0
            ending_iter = 2047
            if abs(max_val) > abs(min_val):
                while starting_iter < ending_iter:
                    if hist[starting_iter] == 0:
                        starting_iter += 1
                        continue
                    else:
                        break
                starting_iter += int((ending_iter - starting_iter) * 0.6)
            else:
                while ending_iter > 0:
                    if hist[ending_iter] == 0:
                        ending_iter -= 1
                        continue
                    else:
                        break
                starting_iter = int(0.6 * ending_iter)
        bin_width = hist_edeges[1] - hist_edeges[0]
637 638

        P_sum = len(np.array(activation_blob).ravel())
639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736
        min_kl_divergence = 0
        min_kl_index = 0
        kl_inited = False
        for i in range(starting_iter, ending_iter + 1):
            reference_distr_P = hist[0:i].tolist()
            outliers_count = sum(hist[i:2048])
            if reference_distr_P[i - 1] == 0:
                continue
            reference_distr_P[i - 1] += outliers_count
            reference_distr_bins = reference_distr_P[:]
            candidate_distr_Q = hist[0:i].tolist()
            num_merged_bins = i / num_quantized_bins
            candidate_distr_Q_quantized = [0] * num_quantized_bins
            j_start = 0
            j_end = num_merged_bins
            for idx in xrange(num_quantized_bins):
                candidate_distr_Q_quantized[idx] = sum(candidate_distr_Q[
                    j_start:j_end])
                j_start += num_merged_bins
                j_end += num_merged_bins
                if (idx + 1) == num_quantized_bins - 1:
                    j_end = i
            candidate_distr_Q = self.__expand_quantized_bins(
                candidate_distr_Q_quantized, reference_distr_bins)
            Q_sum = sum(candidate_distr_Q)
            kl_divergence = self.__safe_entropy(reference_distr_P, P_sum,
                                                candidate_distr_Q, Q_sum)
            if not kl_inited:
                min_kl_divergence = kl_divergence
                min_kl_index = i
                kl_inited = True
            elif kl_divergence < min_kl_divergence:
                min_kl_divergence = kl_divergence
                min_kl_index = i
            else:
                pass
        if min_kl_index == 0:
            while starting_iter > 0:
                if hist[starting_iter] == 0:
                    starting_iter -= 1
                    continue
                else:
                    break
            min_kl_index = starting_iter
        return (min_kl_index + 0.5) * bin_width

    @staticmethod
    def __dot(program, output_name="model.dot"):
        '''
        Generate the graphiz dot file for debugging.
        '''
        dot_graph = ""
        dot_nodes = []
        dot_edges = []
        dot_graph += "digraph pm {\n"
        for block in program.blocks:
            ops = list(block.ops)
            for index, op in enumerate(ops):
                op_type = op.type
                op_name = op_type + "_" + op.output_arg_names[0].replace(
                    ".", "_") + "___" + str(index)
                for name in op.input_arg_names:
                    name = name.replace(".", "_")
                    dot_edge = name + " -> " + op_name
                    if dot_edge not in dot_edges:
                        dot_edges.append(dot_edge)
                    dot_node = name + " [shape=oval, style=filled, fillcolor=yellow]"
                    if dot_node not in dot_nodes:
                        dot_nodes.append(dot_node)

                for name in op.output_arg_names:
                    name = name.replace(".", "_")
                    dot_edge = op_name + " -> " + name
                    if dot_edge not in dot_edges:
                        dot_edges.append(dot_edge)
                if op_type in Calibrator.supported_int8_op_type:
                    if op_type == "conv2d" and op.has_attr(
                            'force_fp32_output') and op.attr(
                                "force_fp32_output"):
                        dot_node = op_name + " [shape=box, style=filled, color=deeppink]"
                    else:
                        dot_node = op_name + " [shape=box, style=filled, color=greenyellow]"
                elif op_type in ["quantize", "dequantize"]:
                    dot_node = op_name + " [shape=box, style=filled, color=gold]"
                else:
                    dot_node = op_name + " [shape=box, style=filled, fillcolor=red]"

                if dot_node not in dot_nodes:
                    dot_nodes.append(dot_node)

        for dot_edge in dot_edges:
            dot_graph += dot_edge + "\n"
        for dot_node in dot_nodes:
            dot_graph += dot_node + "\n"
        dot_graph += "}"

        with open(output_name, 'w') as f:
            f.write(dot_graph)