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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

from ...magi_depyf.timeline import emit_pass_lifecycle
from ..pass_base import MagiInductorPass


class ReplaceSageAttentionPass(MagiInductorPass):
    """
    A pass to replace flash attention with sage attention.
    """

    def is_applicable(self, graph: torch.fx.Graph, shape: int | None = None) -> bool:
        for node in graph.nodes:
            if node.op == "call_function" and node.target == torch.ops.athena.flash_attn_func:
                return True
        return False

    @emit_pass_lifecycle
    def __call__(self, graph: torch.fx.Graph):
        for node in graph.nodes:
            if node.op == "call_function" and node.target == torch.ops.athena.flash_attn_func:
                node.target = torch.ops.athena.sage_attn_func