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# Licensed under the Apache License, Version 2.0 (the "License");
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# http://www.apache.org/licenses/LICENSE-2.0
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import torch


def cos_similarity(x1: torch.Tensor, x2: torch.Tensor, eps: float = 1e-8) -> torch.Tensor:
    x1_flat = x1.flatten(start_dim=1)
    x2_flat = x2.flatten(start_dim=1)

    dot_product = torch.sum(x1_flat * x2_flat, dim=1)

    norm1 = torch.linalg.norm(x1_flat, ord=2, dim=1)
    norm2 = torch.linalg.norm(x2_flat, ord=2, dim=1)

    similarity = dot_product / (norm1 * norm2 + eps)

    return similarity