52 lines
1.4 KiB
Python
Executable File
52 lines
1.4 KiB
Python
Executable File
import torch
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from torch import nn
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class RMSNorm(nn.Module):
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def __init__(
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self,
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hidden_size: int,
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eps: float = 1e-6,
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) -> None:
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super().__init__()
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self.hidden_size = hidden_size
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self.eps = eps
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self.weight = nn.Parameter(torch.ones(hidden_size))
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@torch.compile
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def rms_forward(
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self,
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x: torch.Tensor,
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) -> torch.Tensor:
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orig_dtype = x.dtype
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x = x.to(torch.float32)
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var = x.pow(2).mean(dim=-1, keepdim=True)
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x.mul_(torch.rsqrt(var + self.eps))
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x = x.to(orig_dtype).mul_(self.weight)
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return x
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@torch.compile
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def add_rms_forward(
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self,
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x: torch.Tensor,
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residual: torch.Tensor,
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) -> tuple[torch.Tensor, torch.Tensor]:
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orig_dtype = x.dtype
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x = x.to(torch.float32).add_(residual.to(torch.float32))
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residual = x.to(orig_dtype)
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var = x.pow(2).mean(dim=-1, keepdim=True)
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x.mul_(torch.rsqrt(var + self.eps))
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x = x.to(orig_dtype).mul_(self.weight)
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return x, residual
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def forward(
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self,
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x: torch.Tensor,
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residual: torch.Tensor | None = None,
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) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
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if residual is None:
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return self.rms_forward(x)
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else:
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return self.add_rms_forward(x, residual)
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