[Core] add comment re. mixed order with valueinfo/input/output

src/finn/core/onnx_exec.py

@@ -61,6 +61,10 @@ def execute_node(node, context, graph):
             # onnxruntime unfortunately does not implement run_node as defined by ONNX,
             # it can only execute entire models -- so we create a model which solely
             # consists of our current node.
+            # note: ensure that the same ValueInfo does not appear both in
+            # graph.value_info as well as graph.output or graph.input
+            # nodes with multiple outputs that are a mix of value_info and
+            # input/outputs may get them reordered below
             node_inputs = list(filter(lambda x: x.name in node.input, graph.input))
             node_inputs += list(
                 filter(lambda x: x.name in node.input, graph.value_info)
@@ -84,15 +88,15 @@ def execute_node(node, context, graph):
             output_list = sess.run(None, input_dict)
 
             for output_ind in range(len(node.output)):
-                #get the name of the target buffer from node.output
+                # get the name of the target buffer from node.output
                 outp = node.output[output_ind]
 
-                #retrieve the index of that name in node_outputs
+                # retrieve the index of that name in node_outputs
                 for i in range(len(node_outputs)):
                     if outp == node_outputs[i].name:
                         list_ind = i
 
-                #use that index to index output_list
+                # use that index to index output_list
                 if output_list[list_ind].shape != context[outp].shape:
                     raise Exception(
                         """Output shapes disagree after node execution: