# Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import copy import itertools from framework import Variable, Parameter, default_main_program, default_startup_program, dtype_is_floating import unique_name from paddle.fluid.initializer import Constant, Xavier from param_attr import ParamAttr, WeightNormParamAttr class LayerHelper(object): def __init__(self, layer_type, **kwargs): self.kwargs = kwargs self.layer_type = layer_type name = self.kwargs.get('name', None) if name is None: self.kwargs['name'] = unique_name.generate(self.layer_type) @property def name(self): return self.kwargs['name'] @property def main_program(self): return default_main_program() @property def startup_program(self): return default_startup_program() def append_op(self, *args, **kwargs): return self.main_program.current_block().append_op(*args, **kwargs) def multiple_input(self, input_param_name='input'): inputs = self.kwargs.get(input_param_name, []) type_error = TypeError( "Input of {0} layer should be Variable or sequence of Variable". format(self.layer_type)) if isinstance(inputs, Variable): inputs = [inputs] elif not isinstance(inputs, list) and not isinstance(inputs, tuple): raise type_error else: for each in inputs: if not isinstance(each, Variable): raise type_error return inputs def input(self, input_param_name='input'): inputs = self.multiple_input(input_param_name) if len(inputs) != 1: raise "{0} layer only takes one input".format(self.layer_type) return inputs[0] @property def param_attr(self): return ParamAttr.to_attr(self.kwargs.get('param_attr', None)) @property def bias_attr(self): return ParamAttr.to_attr(self.kwargs.get('bias_attr', None)) def multiple_param_attr(self, length): param_attr = self.param_attr if isinstance(param_attr, ParamAttr): param_attr = [param_attr] if len(param_attr) != 1 and len(param_attr) != length: raise ValueError("parameter number mismatch") elif len(param_attr) == 1 and length != 1: tmp = [None] * length for i in xrange(length): tmp[i] = copy.deepcopy(param_attr[0]) param_attr = tmp return param_attr def iter_inputs_and_params(self, input_param_name='input'): inputs = self.multiple_input(input_param_name) param_attrs = self.multiple_param_attr(len(inputs)) for ipt, param_attr in itertools.izip(inputs, param_attrs): yield ipt, param_attr def input_dtype(self, input_param_name='input'): inputs = self.multiple_input(input_param_name) dtype = None for each in inputs: if dtype is None: dtype = each.dtype elif dtype != each.dtype: raise ValueError("Data Type mismatch: %d to %d" % (dtype, each.dtype)) return dtype def _create_weight_normalize(self, attr, shape, dtype): from .layers import elementwise_mul, elementwise_div, reshape # Remove these ops when LayerHelper and layers support indicating # program and block. def __norm_op(x, out=None, p=2, dim=None, keep_dim=False, block=self.startup_program.global_block()): if out is None: out = block.create_var( name=unique_name.generate(".".join( [self.name, 'weight_norm_norm'])), dtype=dtype, persistable=False) abs_out = block.create_var( name=unique_name.generate(".".join( [self.name, 'weight_norm_abs'])), dtype=dtype, persistable=False) block.append_op( type='abs', inputs={'X': x}, outputs={'Out': abs_out}) pow_out = block.create_var( name=unique_name.generate(".".join( [self.name, 'weight_norm_pow'])), dtype=dtype, persistable=False) block.append_op( type='pow', inputs={'X': abs_out}, outputs={'Out': pow_out}, attrs={'factor': float(p)}) sum_out = block.create_var( name=unique_name.generate(".".join( [self.name, 'weight_norm_sum'])), dtype=dtype, persistable=False) block.append_op( type='reduce_sum', inputs={'X': pow_out}, outputs={'Out': sum_out}, attrs={ 'dim': dim, 'keep_dim': keep_dim, 'reduce_all': True if dim is None else False }) block.append_op( type='pow', inputs={'X': sum_out}, outputs={'Out': out}, attrs={'factor': 1. / p}) return out def __reshape_op(x, shape, out=None, block=self.startup_program.global_block()): if out is None: out = block.create_var( name=unique_name.generate(".".join( [self.name, 'weight_norm_reshape'])), dtype=dtype, persistable=False) block.append_op( type='reshape', inputs={'X': x}, outputs={'Out': out}, attrs={'shape': shape}) return out def __transpose_op(x, axis, out=None, block=self.startup_program.global_block()): if out is None: out = block.create_var( name=unique_name.generate(".".join( [self.name, 'weight_norm_transpose'])), dtype=dtype, persistable=False) block.append_op( type='transpose', inputs={'X': x}, outputs={'Out': out}, attrs={'axis': axis}) return out def __norm_except_dim(x, out=None, dim=None, block=self.startup_program.global_block()): """Computes the norm over all dimensions except dim""" if out is None: out = block.create_var( name=unique_name.generate(".".join( [self.name, 'weight_norm_norm'])), dtype=dtype, persistable=False) if dim is None: __norm_op(x, out, dim=dim, block=block) elif dim == 0: out_shape = [x.shape[0]] + [1] * (len(x.shape) - 1) reshape = __reshape_op(x, shape=[x.shape[0], -1], block=block) norm = __norm_op(reshape, dim=1, block=block) __reshape_op(norm, out=out, shape=out_shape, block=block) elif dim == len(x.shape) - 1: out_shape = [1] * (len(x.shape) - 1) + [x.shape[-1]] reshape = __reshape_op(x, shape=[-1, x.shape[-1]], block=block) norm = __norm_op(reshape, dim=0, block=block) __reshape_op(norm, out=out, shape=out_shape, block=block) else: perm = range(len(x.shape)) perm[0], perm[dim] = dim, 0 transpose = __transpose_op(x, perm, block=block) norm = __norm_op(transpose, dim=0, block=block) __transpose_op(norm, perm, out=out, block=block) return out def __weight_normalize(g, v, dim): """Calculations for weight normalization""" norm = __norm_except_dim( v, dim=dim, block=self.main_program.current_block()) scale = elementwise_div( x=g, y=norm) # The shapes of g and norm are the same. # Currently, elementwise_mul only support broadcast when the shape # of y is a subset of the shape of x. Thus, we reshape y to squeeze # to achive the subset. w = elementwise_mul( x=v, y=scale if dim is None else reshape( x=scale, shape=[v.shape[dim]]), axis=-1 if dim is None else dim) # To serialize the original parameter for inference, maybe a # parameter rather than a variable should be returned. return w g_param_attr = copy.deepcopy(attr) g_param_attr.name = attr.name + '_g' g_param_shape = [1] * len(shape) if attr.dim is not None: g_param_shape[attr.dim] = shape[attr.dim] v_param_attr = copy.deepcopy(attr) v_param_attr.name = attr.name + '_v' v_param_shape = shape # Add to startup_program to initialize g and v. # Try to reconstruct the initializer of w by initializing g and v. # Set the initializers of g and v as below, then the distribution # of w is the same as initializing w with the given initializer. # For Data-Dependent Initialization, please compute the init-values # of g and v in external and then feed the values to g and v by # executing an extra program. g_param = self.startup_program.global_block().create_parameter( dtype=dtype, shape=g_param_shape, **g_param_attr.to_kwargs(with_initializer=False)) v_param = self.startup_program.global_block().create_parameter( dtype=dtype, shape=v_param_shape, **v_param_attr.to_kwargs(with_initializer=True)) __norm_except_dim( x=v_param, out=g_param, dim=attr.dim, block=self.startup_program.global_block()) # Add weight normalization to main_program g_param = self.main_program.global_block().create_parameter( dtype=dtype, shape=g_param_shape, **g_param_attr.to_kwargs()) v_param = self.main_program.global_block().create_parameter( dtype=dtype, shape=v_param_shape, **v_param_attr.to_kwargs()) w_param = __weight_normalize(g_param, v_param, dim=attr.dim) return w_param def create_parameter(self, attr, shape, dtype, is_bias=False, default_initializer=None): # Deepcopy the attr so that parameters can be shared in program attr = copy.deepcopy(attr) assert isinstance(attr, ParamAttr) suffix = 'b' if is_bias else 'w' if attr.name is None: attr.name = unique_name.generate(".".join([self.name, suffix])) if default_initializer is None and attr.initializer is None: if is_bias: attr.set_default_bias_initializer() else: attr.set_default_param_initializer() else: attr.set_default_initializer(default_initializer) # If weight normalization is set, insert extra parameters and ops. # Refer to https://arxiv.org/pdf/1602.07868.pdf if isinstance(attr, WeightNormParamAttr): param = self._create_weight_normalize(attr, shape, dtype) WeightNormParamAttr.params_with_weight_norm.append(param) return param self.startup_program.global_block().create_parameter( dtype=dtype, shape=shape, **attr.to_kwargs(with_initializer=True)) return self.main_program.global_block().create_parameter( dtype=dtype, shape=shape, **attr.to_kwargs()) def get_parameter(self, name): param = self.main_program.global_block().var(name) if not isinstance(param, Parameter): raise ValueError("no Parameter name %s found" % name) return param def create_tmp_variable(self, dtype, stop_gradient=False): return self.main_program.current_block().create_var( name=unique_name.generate(".".join([self.name, 'tmp'])), dtype=dtype, persistable=False, stop_gradient=stop_gradient) def create_variable(self, *args, **kwargs): return self.main_program.current_block().create_var(*args, **kwargs) def create_global_variable(self, persistable=False, *args, **kwargs): """ create global variable, note that there is no initializer for this global variable. Args: persistable(bool): True if it is a checkpoint value. *args: See create_var's documentation **kwargs: See create_var's documentation Returns(Variable): the created variable. """ return self.main_program.global_block().create_var( *args, persistable=persistable, **kwargs) def create_or_get_global_variable(self, name, *args, **kwargs): """ Creates a global variable if not exists and returns the variable and a boolean flag which is true when it is a new variable. """ if self.main_program.global_block().has_var(name): return self.main_program.global_block().var(name), False else: return self.create_global_variable(name=name, *args, **kwargs), True def set_variable_initializer(self, var, initializer): assert isinstance(var, Variable) self.startup_program.global_block().create_var( name=var.name, type=var.type, dtype=var.dtype, shape=var.shape, persistable=True, initializer=initializer) def append_bias_op(self, input_var, dim_start=1, dim_end=None): """ Append bias operator and return its output. If the user does not set bias_attr, append_bias_op will return input_var :param input_var: the input variable. The len(input_var.shape) is larger or equal than 2. :bias_initializer: an instance of a subclass of Initializer used to initialize the bias :param dim_start: :param dim_end: the shape of the bias will be input_var.shape[dim_start:dim_end]. The bias is broadcasted to other dimensions and added to input_var to get the output """ size = list(input_var.shape[dim_start:dim_end]) bias_attr = self.bias_attr if not bias_attr: return input_var b = self.create_parameter( attr=bias_attr, shape=size, dtype=input_var.dtype, is_bias=True) tmp = self.create_tmp_variable(dtype=input_var.dtype) self.append_op( type='elementwise_add', inputs={'X': [input_var], 'Y': [b]}, outputs={'Out': [tmp]}, attrs={'axis': dim_start}) return tmp def append_activation(self, input_var): act = self.kwargs.get('act', None) if act is None: return input_var if isinstance(act, basestring): act = {'type': act} tmp = self.create_tmp_variable(dtype=input_var.dtype) if 'use_mkldnn' in self.kwargs: act['use_mkldnn'] = self.kwargs.get('use_mkldnn') act_type = act.pop('type') if 'use_mkldnn' in self.kwargs: act['use_mkldnn'] = self.kwargs.get('use_mkldnn') self.append_op( type=act_type, inputs={"X": [input_var]}, outputs={"Out": [tmp]}, attrs=act) return tmp def _get_default_initializer(self, dtype): if dtype is None or dtype_is_floating(dtype) is True: return Xavier() else: # For integer and boolean types, initialize with all zeros return Constant() def is_instance(self, param_name, cls): param = self.kwargs.get(param_name, None) if not isinstance(param, cls): raise TypeError("The input {0} parameter of method {1} must be {2}", param_name, self.layer_type, cls.__name__)