# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License" # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import logging import sys import copy import numpy as np from functools import reduce from ..core import VarWrapper, OpWrapper, GraphWrapper from .group_param import collect_convs from .criterion import CRITERION from .idx_selector import IDX_SELECTOR from ..common import get_logger __all__ = ["Pruner"] _logger = get_logger(__name__, level=logging.INFO) class Pruner(): """The pruner used to prune channels of convolution. Args: criterion(str|function): the criterion used to sort channels for pruning. idx_selector(str|function): """ def __init__(self, criterion="l1_norm", idx_selector="default_idx_selector"): if isinstance(criterion, str): self.criterion = CRITERION.get(criterion) else: self.criterion = criterion if isinstance(idx_selector, str): self.idx_selector = IDX_SELECTOR.get(idx_selector) else: self.idx_selector = idx_selector self.pruned_weights = False def prune(self, program, scope, params, ratios, place=None, lazy=False, only_graph=False, param_backup=False, param_shape_backup=False): """Pruning the given parameters. Args: program(paddle.static.Program): The program to be pruned. scope(fluid.Scope): The scope storing paramaters to be pruned. params(list): A list of parameter names to be pruned. ratios(list): A list of ratios to be used to pruning parameters. place(fluid.Place): The device place of filter parameters. Defalut: None. lazy(bool): True means setting the pruned elements to zero. False means cutting down the pruned elements. Default: False. only_graph(bool): True means only modifying the graph. False means modifying graph and variables in scope. Default: False. param_backup(bool): Whether to return a dict to backup the values of parameters. Default: False. param_shape_backup(bool): Whether to return a dict to backup the shapes of parameters. Default: False. Returns: tuple: ``(pruned_program, param_backup, param_shape_backup)``. ``pruned_program`` is the pruned program. ``param_backup`` is a dict to backup the values of parameters. ``param_shape_backup`` is a dict to backup the shapes of parameters. """ self.pruned_list = [] graph = GraphWrapper(program.clone()) param_backup = {} if param_backup else None param_shape_backup = {} if param_shape_backup else None visited = {} pruned_params = [] for param, ratio in zip(params, ratios): _logger.info("pruning: {}".format(param)) if graph.var(param) is None: _logger.warn( "Variable[{}] to be pruned is not in current graph.".format( param)) continue group = collect_convs([param], graph, visited)[0] # [(name, axis, pruned_idx)] if group is None or len(group) == 0: continue if only_graph and self.idx_selector.__name__ == "default_idx_selector": param_v = graph.var(param) pruned_num = int(round(param_v.shape()[0] * ratio)) pruned_idx = [0] * pruned_num for name, axis, _ in group: pruned_params.append((name, axis, pruned_idx)) else: assert ((not self.pruned_weights), "The weights have been pruned once.") group_values = [] for name, axis, pruned_idx in group: values = np.array(scope.find_var(name).get_tensor()) group_values.append((name, values, axis, pruned_idx)) scores = self.criterion( group_values, graph) # [(name, axis, score, pruned_idx)] pruned_params.extend(self.idx_selector(scores, ratio)) merge_pruned_params = {} for param, pruned_axis, pruned_idx in pruned_params: if param not in merge_pruned_params: merge_pruned_params[param] = {} if pruned_axis not in merge_pruned_params[param]: merge_pruned_params[param][pruned_axis] = [] merge_pruned_params[param][pruned_axis].append(pruned_idx) for param_name in merge_pruned_params: for pruned_axis in merge_pruned_params[param_name]: pruned_idx = np.concatenate(merge_pruned_params[param_name][ pruned_axis]) param = graph.var(param_name) if not lazy: _logger.debug("{}\t{}\t{}\t{}".format( param.name(), pruned_axis, param.shape()[pruned_axis], len(pruned_idx))) if param_shape_backup is not None: origin_shape = copy.deepcopy(param.shape()) param_shape_backup[param.name()] = origin_shape new_shape = list(param.shape()) new_shape[pruned_axis] -= len(pruned_idx) param.set_shape(new_shape) if not only_graph: param_t = scope.find_var(param.name()).get_tensor() if param_backup is not None and ( param.name() not in param_backup): param_backup[param.name()] = copy.deepcopy( np.array(param_t)) try: pruned_param = self._prune_tensor( np.array(param_t), pruned_idx, pruned_axis=pruned_axis, lazy=lazy) except IndexError as e: _logger.error("Pruning {}, but get [{}]".format( param.name(), e)) param_t.set(pruned_param, place) graph.update_groups_of_conv() graph.infer_shape() self.pruned_weights = (not only_graph) return graph.program, param_backup, param_shape_backup def _prune_tensor(self, tensor, pruned_idx, pruned_axis, lazy=False): """ Pruning a array by indexes on given axis. Args: tensor(numpy.array): The target array to be pruned. pruned_idx(list): The indexes to be pruned. pruned_axis(int): The axis of given array to be pruned on. lazy(bool): True means setting the pruned elements to zero. False means remove the pruned elements from memory. default: False. Returns: numpy.array: The pruned array. """ mask = np.zeros(tensor.shape[pruned_axis], dtype=bool) mask[pruned_idx] = True def func(data): return data[~mask] def lazy_func(data): data[mask] = 0 return data if lazy: return np.apply_along_axis(lazy_func, pruned_axis, tensor) else: return np.apply_along_axis(func, pruned_axis, tensor)