diff --git a/chunk_codegen.py b/chunk_codegen.py
index 40196285e..e2786d5e2 100644
--- a/chunk_codegen.py
+++ b/chunk_codegen.py
@@ -857,112 +857,6 @@ class FlowTracer(object):
                     )
         return self.flow_trace
 
-    def _detect_flow(
-        self, start_idx, start_dim, end_idx, end_dim, index_tracer: IndexTracer
-    ):
-        inputs, outputs = _find_chunk_compute_input_and_output_nodes(
-            self.node_list[start_idx : end_idx + 1]
-        )
-        chunk_info = {
-            "region": (start_idx, end_idx),
-            "inputs": inputs,
-            "inputs_non_chunk": [],
-            "inputs_dim": start_dim,
-            "outputs": outputs,
-            "outputs_dim": end_dim,
-            "args": {},
-        }
-        flow_block = False
-
-        # TODO don't allow multi outputs now
-        if len(outputs) > 1:
-            flow_block = True
-            return flow_block, chunk_info
-
-        # for idx in range(start_idx, end_idx + 1):
-        #     node = self.node_list[idx]
-        #     mix_flow_node = self._get_flow_mix_node(node)
-        #     if mix_flow_node is None:
-        #         continue
-
-        #     # if there is a flow mix, op must be in [mul, add, matmul]
-        #     # element-wise op requires dim to be equal in every dim
-        #     if any(n in node.name for n in ["mul", "add"]):
-        #         for i in node.args:
-        #             if type(i) == type(mix_flow_node) and i != mix_flow_node:
-        #                 main_flow_var = i
-        #         # if mix flow is a broadcast in chunk dim,
-        #         # TODO: need to move that flow out of the chunk
-        #         mix_flow_node_dim = index_tracer.get_node_chunk_dim(
-        #             self.node_list[end_idx], end_dim, node
-        #         )
-        #         # TODO: we need to loop every dim
-        #         if isinstance(mix_flow_node_dim, list):
-        #             mix_flow_node_dim = mix_flow_node_dim[0]
-        #         if mix_flow_node_dim is None:
-        #             flow_block = True
-        #             break
-        #         if _get_node_shape(mix_flow_node)[mix_flow_node_dim] == 1:
-        #             flow_block = False
-        #             for i in self._get_same_flow_node(
-        #                 chunk_info["inputs"], mix_flow_node
-        #             ):
-        #                 chunk_info["inputs"].remove(i)
-        #         # else, we need to chunk mix var as well
-        #         else:
-        #             # TODO chunk another value
-        #             flow_block = True
-        #             break
-        #     else:
-        #         raise NotImplementedError("%s not implemented" % node.name)
-        # if flow_block:
-        #     flow_block = True
-        #     return flow_block, chunk_info
-
-        inputs_dim = []
-        remove_inputs = []
-        for input_node in chunk_info["inputs"]:
-            input_dict = {}
-            for user in input_node.users.keys():
-                if _is_non_compute_node(user):
-                    continue
-                user_idx = _find_idx_by_name(user.name, self.node_list)
-                dim = None
-                if start_dim <= user_idx < end_idx:
-                    dim = index_tracer.get_node_chunk_dim(
-                        self.node_list[end_idx], end_dim, input_node
-                    )
-                    # TODO: we need to loop every dim
-                    if isinstance(dim, list):
-                        dim = dim[0]
-                elif user_idx == end_idx:
-                    dim = end_dim
-                # n has relation with chunk dim
-                if dim is not None and _get_node_shape(user)[dim] != 1:
-                    input_dict[user_idx] = dim
-            if len(input_dict) == 0:
-                remove_inputs.append(input_node)
-            else:
-                inputs_dim.append(input_dict)
-        chunk_info["inputs_dim"] = inputs_dim
-        for i in remove_inputs:
-            if i in chunk_info["inputs"]:
-                chunk_info["inputs"].remove(i)
-
-        duplicate_result, duplicate_dim = index_tracer.check_index_duplicate(
-            chunk_info, return_dim=True
-        )
-
-        # we need to log input nodes to avoid deleteing them in the loop
-        non_chunk_inputs = _find_chunk_all_input_nodes(
-            self.node_list[start_idx : end_idx + 1]
-        )
-        for i in non_chunk_inputs:
-            if i not in chunk_info["inputs"]:
-                chunk_info["inputs_non_chunk"].append(i)
-
-        return flow_block, chunk_info
-
     def _assgin_single_node_flow(
         self,
         arg_node,