153 lines
5.5 KiB
Python
153 lines
5.5 KiB
Python
# Copyright (c) 2025 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 unittest
|
|
|
|
import numpy as np
|
|
import paddle
|
|
|
|
from paddlenlp.utils.optimizer import AdamWMini
|
|
|
|
|
|
class SimpleTransformerPaddle(paddle.nn.Layer):
|
|
def __init__(self, dim=2048, n_heads=32, vocab_size=100, dtype="float32"):
|
|
super().__init__()
|
|
self.dim = dim
|
|
self.n_heads = n_heads
|
|
self.head_dim = dim // n_heads
|
|
|
|
# Embedding layer
|
|
self.embd = paddle.nn.Embedding(vocab_size, dim, weight_attr=paddle.nn.initializer.Normal(mean=0.0, std=0.02))
|
|
|
|
# Query/Key/Value projections
|
|
self.wq = paddle.nn.Linear(dim, dim, weight_attr=paddle.nn.initializer.Normal(mean=0.0, std=0.02))
|
|
self.wk = paddle.nn.Linear(dim, dim, weight_attr=paddle.nn.initializer.Normal(mean=0.0, std=0.02))
|
|
self.wv = paddle.nn.Linear(dim, dim, weight_attr=paddle.nn.initializer.Normal(mean=0.0, std=0.02))
|
|
|
|
# Attention projection
|
|
self.wo = paddle.nn.Linear(dim, dim, weight_attr=paddle.nn.initializer.Normal(mean=0.0, std=0.02))
|
|
|
|
# LayerNorm layers
|
|
self.ln1 = paddle.nn.LayerNorm(dim)
|
|
self.ln2 = paddle.nn.LayerNorm(dim)
|
|
|
|
# MLP layers
|
|
self.mlp = paddle.nn.Sequential(
|
|
paddle.nn.Linear(dim, 4 * dim, weight_attr=paddle.nn.initializer.Normal(mean=0.0, std=0.02)),
|
|
paddle.nn.ReLU(),
|
|
paddle.nn.Linear(4 * dim, dim, weight_attr=paddle.nn.initializer.Normal(mean=0.0, std=0.02)),
|
|
)
|
|
|
|
# Output layer
|
|
self.lm_head = paddle.nn.Linear(dim, vocab_size, weight_attr=paddle.nn.initializer.Normal(mean=0.0, std=0.02))
|
|
|
|
# Bias parameters
|
|
self.bias = paddle.create_parameter(
|
|
[dim], dtype=dtype, default_initializer=paddle.nn.initializer.Constant(value=0.0)
|
|
)
|
|
|
|
def forward(self, input_ids):
|
|
batch_size = input_ids.shape[0]
|
|
seq_len = input_ids.shape[1]
|
|
|
|
# Embedding
|
|
hidden_states = self.embd(input_ids) # [batch_size, seq_len, dim]
|
|
|
|
# Query/Key/Value projections and reshape for multi-head attention
|
|
query = self.wq(hidden_states) # [batch_size, seq_len, dim]
|
|
key = self.wk(hidden_states) # [batch_size, seq_len, dim]
|
|
value = self.wv(hidden_states) # [batch_size, seq_len, dim]
|
|
|
|
# Reshape to [batch_size, seq_len, n_heads, head_dim]
|
|
query = query.reshape([batch_size, seq_len, self.n_heads, self.head_dim])
|
|
key = key.reshape([batch_size, seq_len, self.n_heads, self.head_dim])
|
|
value = value.reshape([batch_size, seq_len, self.n_heads, self.head_dim])
|
|
|
|
# Transpose to [batch_size, n_heads, seq_len, head_dim]
|
|
query = query.transpose([0, 2, 1, 3])
|
|
key = key.transpose([0, 2, 1, 3])
|
|
value = value.transpose([0, 2, 1, 3])
|
|
|
|
# Scaled dot-product attention
|
|
scale = self.head_dim**-0.5
|
|
attn_weights = paddle.matmul(query * scale, key.transpose([0, 1, 3, 2]))
|
|
attn_weights = paddle.nn.functional.softmax(attn_weights, axis=-1)
|
|
|
|
# Apply attention to values
|
|
attn_output = paddle.matmul(attn_weights, value) # [batch_size, n_heads, seq_len, head_dim]
|
|
|
|
# Reshape back to [batch_size, seq_len, dim]
|
|
attn_output = attn_output.transpose([0, 2, 1, 3])
|
|
attn_output = attn_output.reshape([batch_size, seq_len, self.dim])
|
|
|
|
# Attention output projection with residual connection and layer norm
|
|
attn_output = self.wo(attn_output)
|
|
hidden_states = self.ln1(hidden_states + attn_output)
|
|
|
|
# Feed forward with residual connection and layer norm
|
|
feed_forward = self.mlp(hidden_states)
|
|
hidden_states = self.ln2(hidden_states + feed_forward)
|
|
|
|
# Output
|
|
output = self.lm_head(hidden_states + self.bias)
|
|
|
|
return output
|
|
|
|
|
|
def generate_data(batch_size=32, seq_len=64, vocab_size=100):
|
|
x = np.random.randint(0, vocab_size, size=(batch_size, seq_len))
|
|
y = np.random.randint(0, vocab_size, size=(batch_size, seq_len))
|
|
return x, y
|
|
|
|
|
|
class TestAdamWMini(unittest.TestCase):
|
|
def setUp(self):
|
|
# Set random seeds for reproducibility
|
|
SEED = 1
|
|
np.random.seed(SEED)
|
|
paddle.seed(SEED)
|
|
DTYPE = "float32"
|
|
paddle.set_default_dtype(DTYPE)
|
|
|
|
def test_adamw_mini(self):
|
|
lr = 1e-3
|
|
beta1 = 0.9
|
|
beta2 = 0.999
|
|
epsilon = 1e-8
|
|
weight_decay = 0.01
|
|
dim = 2048
|
|
n_heads = 32
|
|
model = SimpleTransformerPaddle()
|
|
|
|
optimizer = AdamWMini(
|
|
model.named_parameters(),
|
|
learning_rate=lr,
|
|
weight_decay=weight_decay,
|
|
beta1=beta1,
|
|
beta2=beta2,
|
|
epsilon=epsilon,
|
|
dim=dim,
|
|
n_heads=n_heads,
|
|
)
|
|
|
|
for _ in range(2):
|
|
x_np, _ = generate_data()
|
|
x = paddle.to_tensor(x_np, dtype="int64")
|
|
|
|
output = model(x)
|
|
loss = paddle.mean(output)
|
|
loss.backward()
|
|
optimizer.step()
|
|
optimizer.clear_grad()
|