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author | Gustaf Rydholm <gustaf.rydholm@gmail.com> | 2023-08-25 23:19:14 +0200 |
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committer | Gustaf Rydholm <gustaf.rydholm@gmail.com> | 2023-08-25 23:19:14 +0200 |
commit | 49ca6ade1a19f7f9c702171537fe4be0dfcda66d (patch) | |
tree | 20062ed1910758481f3d5fff11159706c7b990c6 /text_recognizer/networks/transformer/embeddings/rotary.py | |
parent | 0421daf6bd97596703f426ba61c401599b538eeb (diff) |
Rename and add flash atten
Diffstat (limited to 'text_recognizer/networks/transformer/embeddings/rotary.py')
-rw-r--r-- | text_recognizer/networks/transformer/embeddings/rotary.py | 67 |
1 files changed, 0 insertions, 67 deletions
diff --git a/text_recognizer/networks/transformer/embeddings/rotary.py b/text_recognizer/networks/transformer/embeddings/rotary.py deleted file mode 100644 index ca0a260..0000000 --- a/text_recognizer/networks/transformer/embeddings/rotary.py +++ /dev/null @@ -1,67 +0,0 @@ -"""Roatary embedding. - -Stolen from lucidrains: - https://github.com/lucidrains/rotary-embedding-torch - -Explanation of roatary: - https://blog.eleuther.ai/rotary-embeddings/ -""" -from inspect import isfunction - -from einops import rearrange, repeat -import torch -from torch import Tensor, nn - - -class RotaryEmbedding(nn.Module): - """Rotary positional embedding.""" - - def __init__(self, dim: int) -> None: - super().__init__() - inv_freqs = 1.0 / (10000 ** (torch.arange(0, dim, 2).float() / dim)) - self.register_buffer("inv_freqs", inv_freqs) - self.cache = {} - - def rotate(self, t: Tensor, dim: int = -2) -> Tensor: - """Rotate vector.""" - device, n = t.device, t.shape[dim] - freqs = self.forward(lambda: torch.arange(n, device=device), cache_key=n) - return apply_rotary_emb(t, freqs) - - def forward(self, t: Tensor, cache_key: int) -> Tensor: - """Encodes tensor x with rotary embeddings.""" - if cache_key in self.cache: - return self.cache[cache_key] - - if isfunction(t): - t = t() - - freqs = self.inv_freqs - freqs = torch.einsum("..., f -> ... f", t.type(freqs.dtype), freqs) - freqs = repeat(freqs, "... n -> ... (n r)", r=2) - self.cache[cache_key] = freqs - return freqs - - -def rotate_half(x: Tensor) -> Tensor: - x = rearrange(x, "... (d r) -> ... d r", r=2) - x1, x2 = x.unbind(dim=-1) - x = torch.stack((-x2, x1), dim=-1) - return rearrange(x, "... d r -> ... (d r)") - - -def apply_rotary_emb(t: Tensor, freqs: Tensor, start_index: int = 0) -> Tensor: - freqs = freqs.to(t) - rot_dim = freqs.shape[-1] - end_index = start_index + rot_dim - assert rot_dim <= t.shape[-1], ( - f"feature dimension {t.shape[-1]} is not of sufficient size to rotate" - f"in all the positions {rot_dim}" - ) - t_left, t, t_right = ( - t[..., :start_index], - t[..., start_index:end_index], - t[..., end_index:], - ) - t = (t * freqs.cos()) + (rotate_half(t) * freqs.sin()) - return torch.cat((t_left, t, t_right), dim=-1) |