pytorch/torch/nn/modules/linear.py
zeshengzong a7f8de2198 Add nn.Bilinear param validation (#149018)
Fixes #103425

## Changes

- Add doc description size value `must be > 0`
- Add validation for `in1_features` param

Currently, only `in1_features` will cause runtime error, if add checks for `in2_features` and `out_features` as well, might be kind of BC breaking.

```python
import torch
from torch import nn

class lenet(nn.Module):
    def __init__(self):
        super(lenet, self).__init__()
        self.conv = nn.Conv2d(in_channels=3, out_channels=16, kernel_size=5, stride=1)

        # Error, `in1_features=1, in2_features=0, out_features=0` no error
        self.linear = nn.Bilinear(in1_features=0, in2_features=0, out_features=0)

    def forward(self, x):
        # 1st block
        x = self.conv(x)
        x = self.linear(x)

        return x

if __name__ == '__main__':
    net = lenet()

```

## Test Result

```bash
pytest test/test_nn.py -k test_bilinear -vv
```

![image](https://github.com/user-attachments/assets/20617ba9-bac5-4db2-aecc-1831dbc8eb43)

![image](https://github.com/user-attachments/assets/401e4e1f-051a-4e1c-952b-48e85de64b0b)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/149018
Approved by: https://github.com/mikaylagawarecki
2025-03-14 19:26:12 +00:00

296 lines
11 KiB
Python

# mypy: allow-untyped-defs
import math
from typing import Any
import torch
from torch import Tensor
from torch.nn import functional as F, init
from torch.nn.parameter import Parameter, UninitializedParameter
from .lazy import LazyModuleMixin
from .module import Module
__all__ = [
"Bilinear",
"Identity",
"LazyLinear",
"Linear",
]
class Identity(Module):
r"""A placeholder identity operator that is argument-insensitive.
Args:
args: any argument (unused)
kwargs: any keyword argument (unused)
Shape:
- Input: :math:`(*)`, where :math:`*` means any number of dimensions.
- Output: :math:`(*)`, same shape as the input.
Examples::
>>> m = nn.Identity(54, unused_argument1=0.1, unused_argument2=False)
>>> input = torch.randn(128, 20)
>>> output = m(input)
>>> print(output.size())
torch.Size([128, 20])
"""
def __init__(self, *args: Any, **kwargs: Any) -> None:
super().__init__()
def forward(self, input: Tensor) -> Tensor:
return input
class Linear(Module):
r"""Applies an affine linear transformation to the incoming data: :math:`y = xA^T + b`.
This module supports :ref:`TensorFloat32<tf32_on_ampere>`.
On certain ROCm devices, when using float16 inputs this module will use :ref:`different precision<fp16_on_mi200>` for backward.
Args:
in_features: size of each input sample
out_features: size of each output sample
bias: If set to ``False``, the layer will not learn an additive bias.
Default: ``True``
Shape:
- Input: :math:`(*, H_\text{in})` where :math:`*` means any number of
dimensions including none and :math:`H_\text{in} = \text{in\_features}`.
- Output: :math:`(*, H_\text{out})` where all but the last dimension
are the same shape as the input and :math:`H_\text{out} = \text{out\_features}`.
Attributes:
weight: the learnable weights of the module of shape
:math:`(\text{out\_features}, \text{in\_features})`. The values are
initialized from :math:`\mathcal{U}(-\sqrt{k}, \sqrt{k})`, where
:math:`k = \frac{1}{\text{in\_features}}`
bias: the learnable bias of the module of shape :math:`(\text{out\_features})`.
If :attr:`bias` is ``True``, the values are initialized from
:math:`\mathcal{U}(-\sqrt{k}, \sqrt{k})` where
:math:`k = \frac{1}{\text{in\_features}}`
Examples::
>>> m = nn.Linear(20, 30)
>>> input = torch.randn(128, 20)
>>> output = m(input)
>>> print(output.size())
torch.Size([128, 30])
"""
__constants__ = ["in_features", "out_features"]
in_features: int
out_features: int
weight: Tensor
def __init__(
self,
in_features: int,
out_features: int,
bias: bool = True,
device=None,
dtype=None,
) -> None:
factory_kwargs = {"device": device, "dtype": dtype}
super().__init__()
self.in_features = in_features
self.out_features = out_features
self.weight = Parameter(
torch.empty((out_features, in_features), **factory_kwargs)
)
if bias:
self.bias = Parameter(torch.empty(out_features, **factory_kwargs))
else:
self.register_parameter("bias", None)
self.reset_parameters()
def reset_parameters(self) -> None:
# Setting a=sqrt(5) in kaiming_uniform is the same as initializing with
# uniform(-1/sqrt(in_features), 1/sqrt(in_features)). For details, see
# https://github.com/pytorch/pytorch/issues/57109
init.kaiming_uniform_(self.weight, a=math.sqrt(5))
if self.bias is not None:
fan_in, _ = init._calculate_fan_in_and_fan_out(self.weight)
bound = 1 / math.sqrt(fan_in) if fan_in > 0 else 0
init.uniform_(self.bias, -bound, bound)
def forward(self, input: Tensor) -> Tensor:
return F.linear(input, self.weight, self.bias)
def extra_repr(self) -> str:
return f"in_features={self.in_features}, out_features={self.out_features}, bias={self.bias is not None}"
# This class exists solely to avoid triggering an obscure error when scripting
# an improperly quantized attention layer. See this issue for details:
# https://github.com/pytorch/pytorch/issues/58969
# TODO: fail fast on quantization API usage error, then remove this class
# and replace uses of it with plain Linear
class NonDynamicallyQuantizableLinear(Linear):
def __init__(
self,
in_features: int,
out_features: int,
bias: bool = True,
device=None,
dtype=None,
) -> None:
super().__init__(
in_features, out_features, bias=bias, device=device, dtype=dtype
)
class Bilinear(Module):
r"""Applies a bilinear transformation to the incoming data: :math:`y = x_1^T A x_2 + b`.
Args:
in1_features: size of each first input sample, must be > 0
in2_features: size of each second input sample, must be > 0
out_features: size of each output sample, must be > 0
bias: If set to ``False``, the layer will not learn an additive bias.
Default: ``True``
Shape:
- Input1: :math:`(*, H_\text{in1})` where :math:`H_\text{in1}=\text{in1\_features}` and
:math:`*` means any number of additional dimensions including none. All but the last dimension
of the inputs should be the same.
- Input2: :math:`(*, H_\text{in2})` where :math:`H_\text{in2}=\text{in2\_features}`.
- Output: :math:`(*, H_\text{out})` where :math:`H_\text{out}=\text{out\_features}`
and all but the last dimension are the same shape as the input.
Attributes:
weight: the learnable weights of the module of shape
:math:`(\text{out\_features}, \text{in1\_features}, \text{in2\_features})`.
The values are initialized from :math:`\mathcal{U}(-\sqrt{k}, \sqrt{k})`, where
:math:`k = \frac{1}{\text{in1\_features}}`
bias: the learnable bias of the module of shape :math:`(\text{out\_features})`.
If :attr:`bias` is ``True``, the values are initialized from
:math:`\mathcal{U}(-\sqrt{k}, \sqrt{k})`, where
:math:`k = \frac{1}{\text{in1\_features}}`
Examples::
>>> m = nn.Bilinear(20, 30, 40)
>>> input1 = torch.randn(128, 20)
>>> input2 = torch.randn(128, 30)
>>> output = m(input1, input2)
>>> print(output.size())
torch.Size([128, 40])
"""
__constants__ = ["in1_features", "in2_features", "out_features"]
in1_features: int
in2_features: int
out_features: int
weight: Tensor
def __init__(
self,
in1_features: int,
in2_features: int,
out_features: int,
bias: bool = True,
device=None,
dtype=None,
) -> None:
factory_kwargs = {"device": device, "dtype": dtype}
super().__init__()
if in1_features <= 0:
raise ValueError(f"in1_features must be > 0, but got {in1_features}")
self.in1_features = in1_features
self.in2_features = in2_features
self.out_features = out_features
self.weight = Parameter(
torch.empty((out_features, in1_features, in2_features), **factory_kwargs)
)
if bias:
self.bias = Parameter(torch.empty(out_features, **factory_kwargs))
else:
self.register_parameter("bias", None)
self.reset_parameters()
def reset_parameters(self) -> None:
bound = 1 / math.sqrt(self.weight.size(1))
init.uniform_(self.weight, -bound, bound)
if self.bias is not None:
init.uniform_(self.bias, -bound, bound)
def forward(self, input1: Tensor, input2: Tensor) -> Tensor:
return F.bilinear(input1, input2, self.weight, self.bias)
def extra_repr(self) -> str:
return (
f"in1_features={self.in1_features}, in2_features={self.in2_features}, "
f"out_features={self.out_features}, bias={self.bias is not None}"
)
class LazyLinear(LazyModuleMixin, Linear):
r"""A :class:`torch.nn.Linear` module where `in_features` is inferred.
In this module, the `weight` and `bias` are of :class:`torch.nn.UninitializedParameter`
class. They will be initialized after the first call to ``forward`` is done and the
module will become a regular :class:`torch.nn.Linear` module. The ``in_features`` argument
of the :class:`Linear` is inferred from the ``input.shape[-1]``.
Check the :class:`torch.nn.modules.lazy.LazyModuleMixin` for further documentation
on lazy modules and their limitations.
Args:
out_features: size of each output sample
bias: If set to ``False``, the layer will not learn an additive bias.
Default: ``True``
Attributes:
weight: the learnable weights of the module of shape
:math:`(\text{out\_features}, \text{in\_features})`. The values are
initialized from :math:`\mathcal{U}(-\sqrt{k}, \sqrt{k})`, where
:math:`k = \frac{1}{\text{in\_features}}`
bias: the learnable bias of the module of shape :math:`(\text{out\_features})`.
If :attr:`bias` is ``True``, the values are initialized from
:math:`\mathcal{U}(-\sqrt{k}, \sqrt{k})` where
:math:`k = \frac{1}{\text{in\_features}}`
"""
cls_to_become = Linear # type: ignore[assignment]
weight: UninitializedParameter
bias: UninitializedParameter # type: ignore[assignment]
def __init__(
self, out_features: int, bias: bool = True, device=None, dtype=None
) -> None:
factory_kwargs = {"device": device, "dtype": dtype}
# bias is hardcoded to False to avoid creating tensor
# that will soon be overwritten.
super().__init__(0, 0, False)
self.weight = UninitializedParameter(**factory_kwargs)
self.out_features = out_features
if bias:
self.bias = UninitializedParameter(**factory_kwargs)
def reset_parameters(self) -> None:
if not self.has_uninitialized_params() and self.in_features != 0:
super().reset_parameters()
def initialize_parameters(self, input) -> None: # type: ignore[override]
if self.has_uninitialized_params():
with torch.no_grad():
self.in_features = input.shape[-1]
self.weight.materialize((self.out_features, self.in_features))
if self.bias is not None:
self.bias.materialize((self.out_features,))
self.reset_parameters()
# TODO: PartialLinear - maybe in sparse?