def gen_function(self) -> str:
        """Generate function for the op

        Returns
        -------
        str
            C++ source code of the function
        """
        target = Target.current()
        func_key = "{target}.{op}.gen_function".format(
            target=target.name(), op=self._attrs["op"]
        )
        func = registry.get(func_key)
        return func(
            self._attrs,
            self.exec_cond_template,
            self.shape_eval_template,
        )
Generate function for the op

        Returns
        -------
        str
            C++ source code of the function
        
python/aitemplate/compiler/ops/gemm_universal/group_gemm_rcr.py