Fix channel axis init for collectors when a collection if required for the input of a node and previous node doesn't need collector (i.e. Dropout->Linear). (SonySemiconductorSolutions#1492)

Author: elad-c

model_compression_toolkit/core/common/model_collector.py

@@ -57,19 +57,21 @@ def create_stats_collector_for_node(node: common.BaseNode,
 
 
 def create_tensor2node(graph: common.Graph,
-                       node: common.BaseNode):
+                       node: common.BaseNode,
+                       next_node_output_channel_axis: int):
     """
     Force statistic collector creation and assignment for a node.
     Args:
         graph: Graph of the node (for retrieving the current tensor).
         node: Node to create a tensor for.
+        next_node_output_channel_axis: channel output axis of next node.
 
     """
     current_sc = graph.get_out_stats_collector(node)
     is_list_nostat_collectors = isinstance(current_sc, list) and len(
         [sc for sc in current_sc if not isinstance(sc, common.NoStatsCollector)]) == 0
     if isinstance(current_sc, common.NoStatsCollector) or current_sc is None or is_list_nostat_collectors:
-        stats_collector = common.StatsCollector(node.out_channel_axis)
+        stats_collector = common.StatsCollector(next_node_output_channel_axis if node.out_channel_axis is None else node.out_channel_axis)
         graph.set_out_stats_collector_to_node(node, stats_collector)
 
 
@@ -175,7 +177,8 @@ def __init__(self, graph: Graph,
                 for ie in graph.incoming_edges(n):
                     input_node = ie.source_node
                     create_tensor2node(graph,
-                                       input_node)
+                                       input_node,
+                                       n.out_channel_axis)
             if sc is not None:
                 graph.set_out_stats_collector_to_node(n, sc)
 

tests_pytest/common_tests/unit_tests/test_model_collector.py

@@ -132,18 +132,32 @@ def test_create_tensor2node_assigns_stats_collector(self):
         graph = Mock()
         node = Mock()
         node.type = DummyLayer
+        node.out_channel_axis = 6
 
         # Simulate absence of an output stats collector.
         graph.get_out_stats_collector = Mock(return_value=None)
 
-        create_tensor2node(graph, node)
+        create_tensor2node(graph, node, 5)
 
         # Verify that set_out_stats_collector_to_node was called with the node and a StatsCollector.
         graph.set_out_stats_collector_to_node.assert_called_once()
         args, _ = graph.set_out_stats_collector_to_node.call_args
         assigned_node, assigned_collector = args
         assert assigned_node is node
         assert isinstance(assigned_collector, StatsCollector)
+        assert assigned_collector.mc.axis == 6
+        assert assigned_collector.mpcc.axis == 6
+
+        node.out_channel_axis = None
+        create_tensor2node(graph, node, 5)
+
+        # Verify that set_out_stats_collector_to_node was called with the node and a StatsCollector.
+        args, _ = graph.set_out_stats_collector_to_node.call_args
+        assigned_node, assigned_collector = args
+        assert assigned_node is node
+        assert isinstance(assigned_collector, StatsCollector)
+        assert assigned_collector.mc.axis == 5
+        assert assigned_collector.mpcc.axis == 5
 
 
 class TestModelCollectorInit:
@@ -226,8 +240,8 @@ def test_bias_correction_creates_tensor2node(self, monkeypatch, fw_impl_mock, pa
 
         calls = []
         # Define a fake function to record call arguments for create_tensor2node.
-        def fake_create_tensor2node(graph, node):
-            calls.append((graph, node))
+        def fake_create_tensor2node(graph, node, next_node_output_channel_axis):
+            calls.append((graph, node, next_node_output_channel_axis))
 
         # Patch create_tensor2node in the model_collector module.
         monkeypatch.setattr(model_collector, "create_tensor2node", fake_create_tensor2node)