def get_pretraining_output(self, mask_label, mask_pos, labels):
"""Get the loss & accuracy for pretraining"""
mask_pos = fluid.layers.cast(x=mask_pos, dtype='int32')
# extract the first token feature in each sentence
next_sent_feat = self.get_pooled_output()
reshaped_emb_out = fluid.layers.reshape(x=self._enc_out,
shape=[-1, self._emb_size])
# extract masked tokens' feature
mask_feat = fluid.layers.gather(input=reshaped_emb_out, index=mask_pos)
# transform: fc
mask_trans_feat = fluid.layers.fc(
input=mask_feat,
size=self._emb_size,
act=self._hidden_act,
param_attr=fluid.ParamAttr(name='mask_lm_trans_fc.w_0',
initializer=self._param_initializer),
bias_attr=fluid.ParamAttr(name='mask_lm_trans_fc.b_0'))
# transform: layer norm
mask_trans_feat = pre_process_layer(mask_trans_feat,
'n',
name='mask_lm_trans')
mask_lm_out_bias_attr = fluid.ParamAttr(
name="mask_lm_out_fc.b_0",
initializer=fluid.initializer.Constant(value=0.0))
if self._weight_sharing:
fc_out = fluid.layers.matmul(
x=mask_trans_feat,
y=fluid.default_main_program().global_block().var(
self._word_emb_name),
transpose_y=True)
fc_out += fluid.layers.create_parameter(shape=[self._voc_size],
dtype=self._dtype,
attr=mask_lm_out_bias_attr,
is_bias=True)
else:
fc_out = fluid.layers.fc(input=mask_trans_feat,
size=self._voc_size,
param_attr=fluid.ParamAttr(
name="mask_lm_out_fc.w_0",
initializer=self._param_initializer),
bias_attr=mask_lm_out_bias_attr)
mask_lm_loss = fluid.layers.softmax_with_cross_entropy(
logits=fc_out, label=mask_label)
mean_mask_lm_loss = fluid.layers.mean(mask_lm_loss)
next_sent_fc_out = fluid.layers.fc(
input=next_sent_feat,
size=2,
param_attr=fluid.ParamAttr(name="next_sent_fc.w_0",
initializer=self._param_initializer),
bias_attr="next_sent_fc.b_0")
next_sent_loss, next_sent_softmax = fluid.layers.softmax_with_cross_entropy(
logits=next_sent_fc_out, label=labels, return_softmax=True)
next_sent_acc = fluid.layers.accuracy(input=next_sent_softmax,
label=labels)
mean_next_sent_loss = fluid.layers.mean(next_sent_loss)
loss = mean_next_sent_loss + mean_mask_lm_loss
return next_sent_acc, mean_mask_lm_loss, loss
def _build_model(self, src_ids, position_ids, sentence_ids, input_mask):
# padding id in vocabulary must be set to 0
emb_out = fluid.layers.embedding(
input=src_ids,
size=[self._voc_size, self._emb_size],
dtype=self._dtype,
param_attr=fluid.ParamAttr(name=self._word_emb_name,
initializer=self._param_initializer),
is_sparse=False)
position_emb_out = fluid.layers.embedding(
input=position_ids,
size=[self._max_position_seq_len, self._emb_size],
dtype=self._dtype,
param_attr=fluid.ParamAttr(name=self._pos_emb_name,
initializer=self._param_initializer))
sent_emb_out = fluid.layers.embedding(
sentence_ids,
size=[self._sent_types, self._emb_size],
dtype=self._dtype,
param_attr=fluid.ParamAttr(name=self._sent_emb_name,
initializer=self._param_initializer))
emb_out = emb_out + position_emb_out
emb_out = emb_out + sent_emb_out
emb_out = pre_process_layer(emb_out,
'nd',
self._prepostprocess_dropout,
name='pre_encoder')
if self._dtype == "float16":
input_mask = fluid.layers.cast(x=input_mask, dtype=self._dtype)
self_attn_mask = fluid.layers.matmul(x=input_mask,
y=input_mask,
transpose_y=True)
self_attn_mask = fluid.layers.scale(x=self_attn_mask,
scale=10000.0,
bias=-1.0,
bias_after_scale=False)
n_head_self_attn_mask = fluid.layers.stack(x=[self_attn_mask] *
self._n_head,
axis=1)
n_head_self_attn_mask.stop_gradient = True
self._enc_out = encoder(
enc_input=emb_out,
attn_bias=n_head_self_attn_mask,
n_layer=self._n_layer,
n_head=self._n_head,
d_key=self._emb_size // self._n_head,
d_value=self._emb_size // self._n_head,
d_model=self._emb_size,
d_inner_hid=self._emb_size * 4,
prepostprocess_dropout=self._prepostprocess_dropout,
attention_dropout=self._attention_dropout,
relu_dropout=0,
hidden_act=self._hidden_act,
preprocess_cmd="",
postprocess_cmd="dan",
param_initializer=self._param_initializer,
name='encoder')
