def _test_gather_random_array(test_case, device):
input = np.random.randn(3, 4, 3, 5)
index = np.random.choice(np.arange(3), size=180, replace=True).reshape(
(3, 4, 3, 5))
np_out = np.take_along_axis(input, index, 1)
output = flow.gather(
flow.tensor(input, dtype=flow.float32, device=flow.device(device)),
1,
flow.tensor(index, dtype=flow.int, device=flow.device(device)),
)
test_case.assertTrue(np.allclose(output.numpy(), np_out))
np_out2 = np.take_along_axis(input, index, 2)
output2 = flow.gather(
flow.tensor(input, dtype=flow.float32, device=flow.device(device)),
2,
flow.tensor(index, dtype=flow.int, device=flow.device(device)),
)
test_case.assertTrue(np.allclose(output2.numpy(), np_out2))
np_out3 = np.take_along_axis(input, index, 3)
output3 = flow.gather(
flow.tensor(input, dtype=flow.float32, device=flow.device(device)),
3,
flow.tensor(index, dtype=flow.int, device=flow.device(device)),
)
test_case.assertTrue(np.allclose(output3.numpy(), np_out3))
def _model(dense_fields, wide_sparse_fields, deep_sparse_fields):
wide_sparse_fields = flow.parallel_cast(
wide_sparse_fields, distribute=flow.distribute.broadcast())
wide_embedding_table = flow.get_variable(
name='wide_embedding',
shape=(FLAGS.wide_vocab_size, 1),
initializer=flow.random_uniform_initializer(minval=-0.05, maxval=0.05),
distribute=flow.distribute.split(0),
)
wide_embedding = flow.gather(params=wide_embedding_table,
indices=wide_sparse_fields)
wide_embedding = flow.reshape(wide_embedding,
shape=(-1, wide_embedding.shape[-1] *
wide_embedding.shape[-2]))
wide_scores = flow.math.reduce_sum(wide_embedding, axis=[1], keepdims=True)
wide_scores = flow.parallel_cast(
wide_scores,
distribute=flow.distribute.split(0),
gradient_distribute=flow.distribute.broadcast())
deep_sparse_fields = flow.parallel_cast(
deep_sparse_fields, distribute=flow.distribute.broadcast())
deep_embedding_table = flow.get_variable(
name='deep_embedding',
shape=(FLAGS.deep_vocab_size, FLAGS.deep_embedding_vec_size),
initializer=flow.random_uniform_initializer(minval=-0.05, maxval=0.05),
distribute=flow.distribute.split(1),
)
deep_embedding = flow.gather(params=deep_embedding_table,
indices=deep_sparse_fields)
deep_embedding = flow.parallel_cast(
deep_embedding,
distribute=flow.distribute.split(0),
gradient_distribute=flow.distribute.split(2))
deep_embedding = flow.reshape(deep_embedding,
shape=(-1, deep_embedding.shape[-1] *
deep_embedding.shape[-2]))
deep_features = flow.concat([deep_embedding, dense_fields], axis=1)
for idx, units in enumerate(DEEP_HIDDEN_UNITS):
deep_features = flow.layers.dense(
deep_features,
units=units,
kernel_initializer=flow.glorot_uniform_initializer(),
bias_initializer=flow.constant_initializer(0.0),
activation=flow.math.relu,
name='fc' + str(idx + 1))
deep_features = flow.nn.dropout(deep_features,
rate=FLAGS.deep_dropout_rate)
deep_scores = flow.layers.dense(
deep_features,
units=1,
kernel_initializer=flow.glorot_uniform_initializer(),
bias_initializer=flow.constant_initializer(0.0),
name='fc' + str(len(DEEP_HIDDEN_UNITS) + 1))
scores = wide_scores + deep_scores
return scores
def sort_op(input, dim: int = -1, descending: bool = False):
num_dims = len(input.shape)
dim = dim if dim >= 0 else dim + num_dims
direction = "DESCENDING" if descending else "ASCENDING"
assert 0 <= dim < num_dims, "dim out of range"
if dim == num_dims - 1:
indices = flow._C.arg_sort(input, direction)
return (flow.gather(input, dim, indices), indices)
else:
perm = get_perm_when_transpose_axis_to_last_dim(num_dims, dim)
x = flow._C.transpose(input, perm=perm)
indices = flow._C.arg_sort(x, direction)
indices = flow._C.transpose(indices, perm=get_inversed_perm(perm))
return (flow.gather(input, dim, indices), indices)
def positional_encoding(position, d_model, name="positional_encoding"):
"""
Do positional encoding
:param position: The position
:param d_model: The hidden dimension in model
:return: shape like (1, position, d_model)
"""
with flow.scope.namespace(name):
# shape = (position, 1)
input_pos = flow.expand_dims(flow.range(position, dtype=flow.float32, name="pos"), axis=1)
# shape = (1, d_model)
input_d_model = flow.expand_dims(flow.range(d_model, dtype=flow.float32, name="d_model"), axis=0)
angle_rads = get_angles(input_pos, input_d_model, d_model)
# Get a even range like (0, 2, 4, 6, ....., d_model)
even_range = flow.range(0, d_model, 2, dtype=flow.int32, name="even_range")
# Do the sin in even indexes
even_out = flow.math.sin(flow.gather(angle_rads, even_range, axis=1))
# Get a odd range like (1, 3, 5, 7, ....., d_model)
odd_range = flow.range(1, d_model, 2, dtype=flow.int32, name="odd_range")
# Do the cos in odd indexes
odd_out = flow.math.cos(flow.gather(angle_rads, odd_range, axis=1))
# Initialize Position encode constant
position_encode = flow.constant(0, dtype=flow.float32, shape=(d_model, position), name="pos_ende")
# Due to the scatter only support row indexes, we need to transpose
even_out = flow.tensor_scatter_nd_update(position_encode,
flow.expand_dims(even_range, axis=1),
flow.transpose(even_out, perm=[1, 0]))
odd_out = flow.tensor_scatter_nd_update(position_encode,
flow.expand_dims(odd_range, axis=1),
flow.transpose(odd_out, perm=[1, 0]))
# Add even indexes value and odd indexes value
out = even_out + odd_out
# Because We have transposed in even_out and odd_out, So we need to transpose back
out = flow.transpose(out, perm=[1, 0])
# Expand dims in dim=0, we get shape like (1, position, d_model)
out = flow.expand_dims(out, axis=0)
return out
def _GatherIndexes(sequence_blob, positions_blob, seq_length, hidden_size):
output = flow.gather(params=sequence_blob,
indices=positions_blob,
axis=2,
batch_dims=2)
output = flow.reshape(output, [-1, hidden_size])
return output
def test_gather_dim_value_runtime_error(test_case):
with test_case.assertRaises(Exception) as context:
x1 = flow.ones((2, 2), dtype=flow.float32, requires_grad=True)
x2 = flow.ones((2, 2), dtype=flow.int64)
y = flow.gather(x1, 2, x2)
test_case.assertTrue(
"Dimension out of range" in str(context.exception))
def test_gather_size_runtime_error(test_case):
with test_case.assertRaises(Exception) as context:
x1 = flow.ones((2, 2), dtype=flow.float32, requires_grad=True)
x2 = flow.ones((4, 2), dtype=flow.int64)
y = flow.gather(x1, 1, x2)
test_case.assertTrue(
"Size does not match at dimension" in str(context.exception))
def get_masked_lm_loss(
logit_blob,
masked_lm_positions,
masked_lm_labels,
label_weights,
max_prediction_per_seq,
):
# gather valid position indices
logit_blob = flow.gather(
logit_blob,
index=masked_lm_positions.unsqueeze(2).repeat(
1, 1, args.vocab_size),
dim=1,
)
logit_blob = flow.reshape(logit_blob, [-1, args.vocab_size])
label_id_blob = flow.reshape(masked_lm_labels, [-1])
# The `positions` tensor might be zero-padded (if the sequence is too
# short to have the maximum number of predictions). The `label_weights`
# tensor has a value of 1.0 for every real prediction and 0.0 for the
# padding predictions.
pre_example_loss = mlm_criterion(logit_blob, label_id_blob)
pre_example_loss = flow.reshape(pre_example_loss,
[-1, max_prediction_per_seq])
numerator = flow.sum(pre_example_loss * label_weights)
denominator = flow.sum(label_weights) + 1e-5
loss = numerator / denominator
return loss
def get_masked_lm_loss(
logit_blob,
masked_lm_positions,
masked_lm_labels,
label_weights,
max_prediction_per_seq=20,
):
# gather valid position indices
logit_blob = flow.gather(
logit_blob,
index=masked_lm_positions.unsqueeze(2).repeat(1, 1, 30522),
dim=1,
)
logit_blob = flow.reshape(logit_blob, [-1, 30522])
label_id_blob = flow.reshape(masked_lm_labels, [-1])
# The `positions` tensor might be zero-padded (if the sequence is too
# short to have the maximum number of predictions). The `label_weights`
# tensor has a value of 1.0 for every real prediction and 0.0 for the
# padding predictions.
pre_example_loss = nn.CrossEntropyLoss(reduction="none")(logit_blob,
label_id_blob)
pre_example_loss = flow.reshape(pre_example_loss,
[-1, max_prediction_per_seq])
sum_label_weight = flow.sum(label_weights, dim=-1)
sum_label_weight = sum_label_weight / label_weights.shape[0]
numerator = flow.sum(pre_example_loss * label_weights)
denominator = flow.sum(label_weights) + 1e-5
loss = numerator / denominator
return logit_blob, loss
def shuffle(
value: remote_blob_util.BlobDef,
seed: Optional[int] = None,
name: Optional[str] = None,
) -> remote_blob_util.BlobDef:
return flow.gather(value,
generate_random_batch_permutation_indices(value, seed))
def test_gather_index_type_runtime_error(test_case):
with test_case.assertRaises(Exception) as context:
x1 = flow.ones((2, 2), dtype=flow.float32, requires_grad=True)
x2 = flow.ones((2, 2), dtype=flow.float32)
y = flow.gather(x1, 1, x2)
test_case.assertTrue(
"gather(): Expected dtype int32 or int64 for index" in str(
context.exception))
def gather_model_parallel_fw_job(
params: oft.Numpy.Placeholder(params_shape, dtype=flow.float),
indices: oft.Numpy.Placeholder(indices_shape, dtype=flow.int32),
):
with flow.scope.placement(device_type, "0:0-3"):
params = params.with_distribute(flow.distribute.split(split_axis))
indices = indices.with_distribute(flow.distribute.broadcast())
return flow.gather(params=params, indices=indices, axis=axis)
def _test_gather_input_0dim_tensor(test_case, device):
input = flow.tensor(1.0).to(device)
input.requires_grad = True
index = flow.tensor([0]).to(device)
output = flow.gather(input, 0, index)
test_case.assertTrue(np.array_equal(output.numpy(), [1.0]))
output.sum().backward()
test_case.assertTrue(np.array_equal(input.grad.numpy(), 1.0))
def test_gather_dim_equal_runtime_error(test_case):
with test_case.assertRaises(Exception) as context:
x1 = flow.ones((2, 2), dtype=flow.float32, requires_grad=True)
x2 = flow.ones((2, 2, 2), dtype=flow.int64)
y = flow.gather(x1, 1, x2)
test_case.assertTrue(
"Index tensor must have the same number of dimensions as input tensor"
in str(context.exception))
def _prob_in_top_k(
self, clean_values, noisy_values, noise_stddev, noisy_top_values
):
"""Helper function to NoisyTopKGating.
Computes the probability that value is in top k, given different random noise.
This gives us a way of backpropagating from a loss that balances the number
of times each expert is in the top k experts per example.
In the case of no noise, pass in None for noise_stddev, and the result will
not be differentiable.
Args:
clean_values: a `Tensor` of shape [batch, n].
noisy_values: a `Tensor` of shape [batch, n]. Equal to clean values plus
normally distributed noise with standard deviation noise_stddev.
noise_stddev: a `Tensor` of shape [batch, n], or None
noisy_top_values: a `Tensor` of shape [batch, m].
"values" Output of tf.top_k(noisy_top_values, m). m >= k+1
Returns:
a `Tensor` of shape [batch, n].
"""
batch = clean_values.size(0)
m = noisy_top_values.size(1)
top_values_flat = noisy_top_values.flatten()
threshold_positions_if_in = (
flow.arange(batch, device=noisy_values.device) * m + self.k
)
threshold_if_in = flow.unsqueeze(
flow.gather(top_values_flat, 0, threshold_positions_if_in), 1
)
is_in = flow.gt(noisy_values, threshold_if_in)
threshold_positions_if_out = threshold_positions_if_in - 1
threshold_if_out = flow.unsqueeze(
flow.gather(top_values_flat, 0, threshold_positions_if_out), 1
)
# is each value currently in the top k.
prob_if_in = cdf((clean_values - threshold_if_in) / noise_stddev)
prob_if_out = cdf((clean_values - threshold_if_out) / noise_stddev)
prob = flow.where(is_in, prob_if_in, prob_if_out)
return prob
def _EmbeddingLookup(input_ids_blob,
vocab_size,
embedding_size=128,
initializer_range=0.02,
word_embedding_name="word_embeddings"):
embedding_table = flow.get_variable(name=word_embedding_name, shape=[vocab_size, embedding_size],
dtype=flow.float,
initializer=CreateInitializer(initializer_range))
output = flow.gather(params=embedding_table, indices=input_ids_blob, axis=0)
return output, embedding_table
def _test_gather(test_case, device):
input = np.array([[1, 2], [3, 4]])
index = np.array([[0, 0], [1, 0]])
np_out = np.take_along_axis(input, index, 0)
output = flow.gather(
flow.tensor(input, dtype=flow.float32, device=flow.device(device)),
0,
flow.tensor(index, dtype=flow.int, device=flow.device(device)),
)
test_case.assertTrue(np.array_equal(output.numpy(), np_out))
def flip(x, dim):
xsize = x.size()
dim = x.dim() + dim if dim < 0 else dim
x = flow.reshape(x, shape=(-1, *xsize[dim:]))
x = flow.reshape(x, shape=(x.size(0), x.size(1), -1))
index = []
index1 = []
for i in range(x.size(1) - 1, -1, -1):
index1.append([i] * x.size(2))
for i in range(x.size(0)):
index.append(index1)
index = flow.Tensor(index).long()
if x.is_cuda:
x = flow.gather(x, index.to("cuda"), dim=1)
else:
x = flow.gather(x, index, dim=1)
return flow.reshape(x, shape=xsize)
def forward(self, sequence_output, masked_lm_positions):
# Gather masked outputs
masked_sequence_output = flow.gather(
sequence_output,
index=masked_lm_positions.unsqueeze(2).expand(-1, -1, self.hidden_size),
dim=1,
)
masked_sequence_output = masked_sequence_output.reshape([-1, self.hidden_size])
masked_sequence_output = self.transform(masked_sequence_output)
masked_sequence_output = self.decoder(masked_sequence_output)
return masked_sequence_output
def do_gather(x_blob, i_blob):
with flow.scope.placement(device_type, "0:0"):
x = flow.get_variable(
"params",
shape=params.shape,
dtype=flow.float32,
initializer=flow.constant_initializer(0),
)
x = x + x_blob
y = flow.gather(x, i_blob, axis=axis, batch_dims=batch_dims)
flow.losses.add_loss(y)
flow.watch_diff(x, compare_fn)
return y
def variable_scope_test_job_2(a=of.FixedTensorDef((2, 5))):
with of.scope.namespace("job2_scope1"):
indices = of.get_variable(
"gather_inds",
shape=(2, ),
dtype=of.int32,
initializer=of.constant_initializer(1),
trainable=False,
)
output = of.gather(a, indices, axis=1)
print("indices op name: ", indices.op_name)
print("gather op name: ", output.op_name)
return output
def forward(self, input):
if self.dim == None:
self.dim = -1
num_axes = len(input.shape)
axis = self.dim if self.dim >= 0 else self.dim + num_axes
assert 0 <= axis < num_axes, "axis out of range"
if axis == num_axes - 1:
if self.largest:
indices = flow._C.top_k(input, self.k)
else:
neg_input = flow.mul(input, -1)
indices = flow._C.top_k(neg_input, self.k)
return (flow.gather(input, axis, indices), indices)
else:
perm = get_perm_when_transpose_axis_to_last_dim(num_axes, axis)
x = flow._C.transpose(input, perm=perm)
if self.largest:
indices = flow._C.top_k(x, self.k)
else:
neg_input = flow.mul(x, -1)
indices = flow._C.top_k(neg_input, self.k)
indices = flow._C.transpose(indices, perm=get_inversed_perm(perm))
return (flow.gather(input, axis, indices), indices)
def _test_gather_backward(test_case, device):
input = np.array([[1, 2], [3, 4]])
index = np.array([[0, 0], [1, 0]])
np_out = np.take_along_axis(input, index, 0)
np_grad = _scatter_add_numpy(np.ones_like(np_out), 0, index, input.shape)
of_input = flow.tensor(
input, dtype=flow.float32, requires_grad=True, device=flow.device(device)
)
output = flow.gather(
of_input, 0, flow.tensor(index, dtype=flow.int64, device=flow.device(device)),
)
out_sum = output.sum()
out_sum.backward()
test_case.assertTrue(np.array_equal(output.numpy(), np_out))
test_case.assertTrue(np.array_equal(of_input.grad.numpy(), np_grad))
def do_gather(x_blob, i_blob):
with flow.scope.placement(device_type, "0:0"):
x = flow.get_variable(
"params",
shape=params.shape,
dtype=flow.float32,
initializer=flow.constant_initializer(0),
)
x = x + x_blob
y = flow.gather(x, i_blob, axis=axis, batch_dims=batch_dims)
lr_scheduler = flow.optimizer.PiecewiseConstantScheduler([],
[1e-3])
flow.optimizer.SGD(lr_scheduler, momentum=0).minimize(y)
flow.watch_diff(x, compare_fn)
return y
def _EmbeddingPostprocessor(
input_blob,
seq_length,
embedding_size,
use_token_type=False,
token_type_ids_blob=None,
token_type_vocab_size=16,
token_type_embedding_name="token_type_embeddings",
use_position_embeddings=True,
position_embedding_name="position_embeddings",
initializer_range=0.02,
max_position_embeddings=512,
dropout_prob=0.1,
):
output = input_blob
if use_token_type:
assert token_type_ids_blob is not None
token_type_table = flow.get_variable(
name=token_type_embedding_name,
shape=[token_type_vocab_size, embedding_size],
dtype=input_blob.dtype,
initializer=CreateInitializer(initializer_range),
)
token_type_embeddings = flow.gather(
params=token_type_table, indices=token_type_ids_blob, axis=0
)
output = output + token_type_embeddings
if use_position_embeddings:
position_table = flow.get_variable(
name=position_embedding_name,
shape=[1, max_position_embeddings, embedding_size],
dtype=input_blob.dtype,
initializer=CreateInitializer(initializer_range),
)
assert seq_length <= max_position_embeddings
if seq_length != max_position_embeddings:
position_table = flow.slice(
position_table, begin=[None, 0, 0], size=[None, seq_length, -1]
)
output = output + position_table
output = _LayerNorm(output, embedding_size)
output = _Dropout(output, dropout_prob)
return output
def _test_batch_gather(test_case, shape, device):
# for example: shape = (3, 2, 2)
x = np.random.randn(*shape)
x_tensor = flow.Tensor(x).to(device)
x_tensor.requires_grad = True
batchsize = x.shape[0]
init_index = np.array([
np.random.randint(batchsize) for i in range(batchsize)
]).astype(np.int64)
batch_gather_index = flow.tensor(init_index).to(device)
batch_gather_out = flow.batch_gather(x_tensor, batch_gather_index)
x_tensor_gather = flow.Tensor(x).to(device)
x_tensor_gather.requires_grad = True
reshaped_shape = [batchsize] # reshaped_shape = [3]
for i in range(len(x.shape) - 1):
reshaped_shape.append(1) # reshaped_shape = [3] -> [3, 1, 1]
gather_index = np.reshape(init_index, reshaped_shape)
gather_index = np.broadcast_to(gather_index, shape).astype(
np.int64) # [3, 1, 1] -> [3, 2, 2]
gather_index = flow.tensor(gather_index).to(device)
gather_out = flow.gather(x_tensor_gather, 0, gather_index)
total_out = batch_gather_out.sum() + gather_out.sum()
total_out.backward()
test_case.assertTrue(
np.allclose(batch_gather_out.numpy(),
gather_out.numpy(),
atol=1e-4,
rtol=1e-4))
test_case.assertTrue(
np.allclose(
x_tensor.grad.numpy(),
x_tensor_gather.grad.numpy(),
atol=1e-4,
rtol=1e-4,
))
test_case.assertTrue(
np.allclose(
x_tensor.grad.numpy(),
x_tensor_gather.grad.numpy(),
atol=1e-4,
rtol=1e-4,
))
def GPT(idx, config, target=None):
b, t = idx.shape
assert t <= config.block_size, "Cannot forward, model block size is exhausted."
#forward the GPT model
#token_embeddings = flow.layers.dense
word_embedding = flow.get_variable(
'word_emb',
initializer=flow.random_normal_initializer(),
shape=(config.vocab_size, config.n_embd))
token_embeddings = flow.gather(word_embedding, idx)
#positions embedding
pos_emb = flow.get_variable(name='pos_emb',
shape=(1, config.block_size, config.n_embd),
dtype=flow.float32,
initializer=flow.zeros_initializer())
#position_embeddings = fpos_emb[:, :t, :] # each position maps to a (learnable) vector
position_embeddings = flow.slice(pos_emb, [None, 0, None], [None, t, None])
x = flow.nn.dropout((token_embeddings + position_embeddings),
config.embd_pdrop)
#Blocks
for block_id in range(config.n_layer):
with flow.scope.namespace('Block' + str(block_id)):
x = Block(x, config)
x = flow.layers.layer_norm(x, name='output_layernorm')
logits = flow.layers.dense(x,
config.vocab_size,
use_bias=False,
activation=flow.zeros_initializer(),
name='output_logits')
loss = None
if target is not None:
#TODO
logits = flow.reshape(logits, [-1, config.vocab_size])
target = flow.reshape(target, [-1])
target = flow.one_hot(target,
depth=config.vocab_size,
dtype=flow.float32)
loss = flow.nn.softmax_cross_entropy_with_logits(logits, target)
return logits, loss
def testIndexedSlicesSGD(
sparse_ids: flow.typing.Numpy.Placeholder(ids_shape, dtype=flow.int32),
) -> flow.typing.Numpy:
with flow.scope.placement(device_type, "0:0"):
embedding_table = flow.get_variable(
name="embeddings",
shape=model_shape,
initializer=flow.random_uniform_initializer(minval=0,
maxval=100),
)
embedding = flow.gather(params=embedding_table * mul_scalar,
indices=sparse_ids)
loss = flow.math.reduce_mean(embedding)
flow.optimizer.SGD(
flow.optimizer.PiecewiseConstantScheduler([], [learning_rate]),
momentum=momentum_beta,
).minimize(loss)
return embedding_table
def EmbeddingLayer(input_ids_blob,
vocab_size,
embedding_size=128,
initializer_range=0.02,
word_embedding_name="Embedding_Layer"):
"""
Embedding Layer
:param input_ids_blob:The input ID Blob
:param vocab_size: The input Vocab size
:param embedding_size: The embedding Size
:param initializer_range: The range of Initializer, Use flow.truncated_normal
:param word_embedding_name: The name of Embedding variable
:return: The output and the Embedding table.
"""
embedding_table = flow.get_variable(name=word_embedding_name+"_Embed",
shape=[vocab_size, embedding_size],
dtype=flow.float32,
initializer=flow.truncated_normal(initializer_range))
output = flow.gather(params=embedding_table, indices=input_ids_blob, axis=0)
return output
def __call__(self, x):
"""
Get embeddings of x
:param x: An flow.int64 Tensor with shape [batchsize, length]
:return: embeddings: float32 tensor with shape [batch_size, length, embedding_size]
padding: float32 tensor with shape [batch_size, length] indicating the
locations of the padding tokens in x.
"""
with flow.scope.namespace("embedding"):
embeddings = flow.gather(self.embedding_table, x, axis=0)
# Scale embedding by the sqrt of the hidden size
embeddings *= self.hidden_size**0.5
# Create binary array of size [batch_size, length]
# where 1 = padding, 0 = not padding
padding = model_utils.get_padding(x)
# Set all padding embedding values to 0
embeddings *= flow.expand_dims(1 - padding, -1)
return embeddings
