backends/transforms/remove_clone_ops.py

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.

# pyre-strict

import torch
from executorch.exir.dialects._ops import ops as exir_ops
from executorch.exir.pass_base import ExportPass, PassResult


def remove_clone_ops(graph: torch.fx.Graph) -> torch.fx.Graph:
    """
    Remove clone op nodes and replace uses with parent node.
    """
    clone_op = exir_ops.edge.aten.clone.default
    for node in graph.nodes:
        if node.op == "call_function" and node.target == clone_op:
            with graph.inserting_after(node):
                node.replace_all_uses_with(node.args[0])

    graph.eliminate_dead_code()
    return graph


class RemoveCloneOpsTransform(ExportPass):
    def call(self, graph_module: torch.fx.GraphModule) -> PassResult:
        graph_module.graph = remove_clone_ops(graph_module.graph)
        return PassResult(graph_module, True)