Method preprocess

exir/backend/test/test_backends_nested.py:131–158

(
        edge_program: ExportedProgram,
        compile_specs: List[CompileSpec],
    )

class Backend1Demo(BackendDetails):
    @staticmethod
    def preprocess(
        edge_program: ExportedProgram,
        compile_specs: List[CompileSpec],
    ) -> PreprocessResult:
        assert isinstance(edge_program, ExportedProgram)
        partitioned_module = to_backend(edge_program, Backend2PartitionerDemo())

        def process(gm):
            processed_bytes = ""
            for node in gm.graph.nodes:
                if node.op == "call_function":
                    if node.target is torch.ops.higher_order.cond:
                        _, true_gm, _ = _get_submodule(gm, node, 1)
                        _, false_gm, _ = _get_submodule(gm, node, 2)
                        processed_bytes += f"{node.target.__name__}({process(true_gm)},{process(false_gm)});"
                    elif node.target is operator.getitem:
                        continue
                    elif node.target is executorch_call_delegate:
                        _, lowered, _ = _get_submodule(gm, node, 0)
                        processed_bytes += f"call_delegate({lowered.processed_bytes});"
                    else:
                        processed_bytes += f"{node.target.__name__};"
            return processed_bytes

        processed_bytes = f"Backend1::({process(partitioned_module.graph_module)})"
        return PreprocessResult(
            processed_bytes=bytes(processed_bytes, encoding="utf8"),
        )


class CondOperatorSupport(OperatorSupportBase):