v1.0

nn/activations.py

+# Copyright 2020 The HuggingFace Team. 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 math
+from collections import OrderedDict
+
+import torch
+from packaging import version
+from torch import Tensor, nn
+
+from nanotron import logging
+
+logger = logging.get_logger(__name__)
+
+
+class PytorchGELUTanh(nn.Module):
+    """
+    A fast C implementation of the tanh approximation of the GeLU activation function. See
+    https://arxiv.org/abs/1606.08415.
+
+    This implementation is equivalent to NewGELU and FastGELU but much faster. However, it is not an exact numerical
+    match due to rounding errors.
+    """
+
+    def __init__(self):
+        super().__init__()
+        if version.parse(torch.__version__) < version.parse("1.12.0"):
+            raise ImportError(
+                f"You are using torch=={torch.__version__}, but torch>=1.12.0 is required to use "
+                "PytorchGELUTanh. Please upgrade torch."
+            )
+
+    def forward(self, input: Tensor) -> Tensor:
+        return nn.functional.gelu(input, approximate="tanh")
+
+
+class NewGELUActivation(nn.Module):
+    """
+    Implementation of the GELU activation function currently in Google BERT repo (identical to OpenAI GPT). Also see
+    the Gaussian Error Linear Units paper: https://arxiv.org/abs/1606.08415
+    """
+
+    def forward(self, input: Tensor) -> Tensor:
+        return 0.5 * input * (1.0 + torch.tanh(math.sqrt(2.0 / math.pi) * (input + 0.044715 * torch.pow(input, 3.0))))
+
+
+class GELUActivation(nn.Module):
+    """
+    Original Implementation of the GELU activation function in Google BERT repo when initially created. For
+    information: OpenAI GPT's GELU is slightly different (and gives slightly different results): 0.5 * x * (1 +
+    torch.tanh(math.sqrt(2 / math.pi) * (x + 0.044715 * torch.pow(x, 3)))) This is now written in C in nn.functional
+    Also see the Gaussian Error Linear Units paper: https://arxiv.org/abs/1606.08415
+    """
+
+    def __init__(self, use_gelu_python: bool = False):
+        super().__init__()
+        if use_gelu_python:
+            self.act = self._gelu_python
+        else:
+            self.act = nn.functional.gelu
+
+    def _gelu_python(self, input: Tensor) -> Tensor:
+        return input * 0.5 * (1.0 + torch.erf(input / math.sqrt(2.0)))
+
+    def forward(self, input: Tensor) -> Tensor:
+        return self.act(input)
+
+
+class FastGELUActivation(nn.Module):
+    """
+    Applies GELU approximation that is slower than QuickGELU but more accurate. See: https://github.com/hendrycks/GELUs
+    """
+
+    def forward(self, input: Tensor) -> Tensor:
+        return 0.5 * input * (1.0 + torch.tanh(input * 0.7978845608 * (1.0 + 0.044715 * input * input)))
+
+
+class QuickGELUActivation(nn.Module):
+    """
+    Applies GELU approximation that is fast but somewhat inaccurate. See: https://github.com/hendrycks/GELUs
+    """
+
+    def forward(self, input: Tensor) -> Tensor:
+        return input * torch.sigmoid(1.702 * input)
+
+
+class ClippedGELUActivation(nn.Module):
+    """
+    Clip the range of possible GeLU outputs between [min, max]. This is especially useful for quantization purpose, as
+    it allows mapping negatives values in the GeLU spectrum. For more information on this trick, please refer to
+    https://arxiv.org/abs/2004.09602.
+
+    Gaussian Error Linear Unit. Original Implementation of the gelu activation function in Google Bert repo when
+    initially created.
+
+    For information: OpenAI GPT's gelu is slightly different (and gives slightly different results): 0.5 * x * (1 +
+    torch.tanh(math.sqrt(2 / math.pi) * (x + 0.044715 * torch.pow(x, 3)))). See https://arxiv.org/abs/1606.08415
+    """
+
+    def __init__(self, min: float, max: float):
+        if min > max:
+            raise ValueError(f"min should be < max (got min: {min}, max: {max})")
+
+        super().__init__()
+        self.min = min
+        self.max = max
+
+    def forward(self, x: Tensor) -> Tensor:
+        return torch.clip(gelu(x), self.min, self.max)
+
+
+class AccurateGELUActivation(nn.Module):
+    """
+    Applies GELU approximation that is faster than default and more accurate than QuickGELU. See:
+    https://github.com/hendrycks/GELUs
+
+    Implemented along with MEGA (Moving Average Equipped Gated Attention)
+    """
+
+    def __init__(self):
+        super().__init__()
+        self.precomputed_constant = math.sqrt(2 / math.pi)
+
+    def forward(self, input: Tensor) -> Tensor:
+        return 0.5 * input * (1 + torch.tanh(self.precomputed_constant * (input + 0.044715 * torch.pow(input, 3))))
+
+
+class SiLUActivation(nn.Module):
+    """
+    See Gaussian Error Linear Units (Hendrycks et al., https://arxiv.org/abs/1606.08415) where the SiLU (Sigmoid Linear
+    Unit) was originally introduced and coined, and see Sigmoid-Weighted Linear Units for Neural Network Function
+    Approximation in Reinforcement Learning (Elfwing et al., https://arxiv.org/abs/1702.03118) and Swish: a Self-Gated
+    Activation Function (Ramachandran et al., https://arxiv.org/abs/1710.05941v1) where the SiLU was experimented with
+    later.
+    """
+
+    def forward(self, input: Tensor) -> Tensor:
+        return nn.functional.silu(input)
+
+
+class MishActivation(nn.Module):
+    """
+    See Mish: A Self-Regularized Non-Monotonic Activation Function (Misra., https://arxiv.org/abs/1908.08681). Also
+    visit the official repository for the paper: https://github.com/digantamisra98/Mish
+    """
+
+    def __init__(self):
+        super().__init__()
+        if version.parse(torch.__version__) < version.parse("1.9.0"):
+            self.act = self._mish_python
+        else:
+            self.act = nn.functional.mish
+
+    def _mish_python(self, input: Tensor) -> Tensor:
+        return input * torch.tanh(nn.functional.softplus(input))
+
+    def forward(self, input: Tensor) -> Tensor:
+        return self.act(input)
+
+
+class LinearActivation(nn.Module):
+    """
+    Applies the linear activation function, i.e. forwarding input directly to output.
+    """
+
+    def forward(self, input: Tensor) -> Tensor:
+        return input
+
+
+class LaplaceActivation(nn.Module):
+    """
+    Applies elementwise activation based on Laplace function, introduced in MEGA as an attention activation. See
+    https://arxiv.org/abs/2209.10655
+
+    Inspired by squared relu, but with bounded range and gradient for better stability
+    """
+
+    def forward(self, input, mu=0.707107, sigma=0.282095):
+        input = (input - mu).div(sigma * math.sqrt(2.0))
+        return 0.5 * (1.0 + torch.erf(input))
+
+
+class ReLUSquaredActivation(nn.Module):
+    """
+    Applies the relu^2 activation introduced in https://arxiv.org/abs/2109.08668v2
+    """
+
+    def forward(self, input):
+        relu_applied = nn.functional.relu(input)
+        squared = torch.square(relu_applied)
+        return squared
+
+
+class ClassInstantier(OrderedDict):
+    def __getitem__(self, key):
+        content = super().__getitem__(key)
+        cls, kwargs = content if isinstance(content, tuple) else (content, {})
+        return cls(**kwargs)
+
+
+ACT2CLS = {
+    "gelu": GELUActivation,
+    "gelu_10": (ClippedGELUActivation, {"min": -10, "max": 10}),
+    "gelu_fast": FastGELUActivation,
+    "gelu_new": NewGELUActivation,
+    "gelu_python": (GELUActivation, {"use_gelu_python": True}),
+    "gelu_pytorch_tanh": PytorchGELUTanh,
+    "gelu_accurate": AccurateGELUActivation,
+    "laplace": LaplaceActivation,
+    "linear": LinearActivation,
+    "mish": MishActivation,
+    "quick_gelu": QuickGELUActivation,
+    "relu": nn.ReLU,
+    "relu2": ReLUSquaredActivation,
+    "relu6": nn.ReLU6,
+    "sigmoid": nn.Sigmoid,
+    "silu": SiLUActivation,
+    "swish": SiLUActivation,
+    "tanh": nn.Tanh,
+}
+ACT2FN = ClassInstantier(ACT2CLS)
+
+
+def get_activation(activation_string):
+    if activation_string in ACT2FN:
+        return ACT2FN[activation_string]
+    else:
+        raise KeyError(f"function {activation_string} not found in ACT2FN mapping {list(ACT2FN.keys())}")
+
+
+# For backwards compatibility with: from activations import gelu_python
+gelu_python = get_activation("gelu_python")
+gelu_new = get_activation("gelu_new")
+gelu = get_activation("gelu")
+gelu_fast = get_activation("gelu_fast")
+quick_gelu = get_activation("quick_gelu")
+silu = get_activation("silu")
+mish = get_activation("mish")
+linear_act = get_activation("linear")

optim/__init__.py

+from nanotron.optim.base import BaseOptimizer
+from nanotron.optim.inherit_from_other_optimizer import InheritFromOtherOptimizer
+from nanotron.optim.named_optimizer import NamedOptimizer
+from nanotron.optim.optimizer_from_gradient_accumulator import OptimizerFromGradientAccumulator
+from nanotron.optim.zero import ZeroDistributedOptimizer
+
+__all__ = [
+    "BaseOptimizer",
+    "InheritFromOtherOptimizer",
+    "NamedOptimizer",
+    "OptimizerFromGradientAccumulator",
+    "ZeroDistributedOptimizer",
+]