File size: 1,922 Bytes
3b7d18f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.

from typing import Callable, Optional

from torch import Tensor, nn
import torch.nn.functional as F


class SwiGLUFFN(nn.Module):
    def __init__(

        self,

        in_features: int,

        hidden_features: Optional[int] = None,

        out_features: Optional[int] = None,

        act_layer: Callable[..., nn.Module] = None,

        drop: float = 0.0,

        bias: bool = True,

    ) -> None:
        super().__init__()
        out_features = out_features or in_features
        hidden_features = hidden_features or in_features
        self.w12 = nn.Linear(in_features, 2 * hidden_features, bias=bias)
        self.w3 = nn.Linear(hidden_features, out_features, bias=bias)

    def forward(self, x: Tensor) -> Tensor:
        x12 = self.w12(x)
        x1, x2 = x12.chunk(2, dim=-1)
        hidden = F.silu(x1) * x2
        return self.w3(hidden)


try:
    from xformers.ops import SwiGLU

    XFORMERS_AVAILABLE = True
except ImportError:
    SwiGLU = SwiGLUFFN
    XFORMERS_AVAILABLE = False


class SwiGLUFFNFused(SwiGLU):
    def __init__(

        self,

        in_features: int,

        hidden_features: Optional[int] = None,

        out_features: Optional[int] = None,

        act_layer: Callable[..., nn.Module] = None,

        drop: float = 0.0,

        bias: bool = True,

    ) -> None:
        out_features = out_features or in_features
        hidden_features = hidden_features or in_features
        hidden_features = (int(hidden_features * 2 / 3) + 7) // 8 * 8
        super().__init__(
            in_features=in_features,
            hidden_features=hidden_features,
            out_features=out_features,
            bias=bias,
        )