The padding of concat is not needed anymore if the inputs are equal.

Author: jirioc

backends/nxp/backend/ir/converter/node_converters/ops_converters/cat_converter.py

@@ -85,6 +85,12 @@ def _is_supported_on_target(
         if dim == 0:
             return False
 
+        # If all input shapes are equal, the neutron is able to pad the last dimension of inputs and outputs.
+        input_shapes = [_get_shape(input_) for input_ in node.all_input_nodes]
+        if input_shapes.count(input_shapes[0]) == len(input_shapes):
+            if dim == len(input_shapes[0]) - 1:
+                return True
+
         # Neutron requires the channels to be a multiple of numMacs. The channels could either be the second or the
         #  last dimension, depending on the formats of the node. The format, however, cannot be determined
         #  during conversion, as it depends on what other nodes are delegated.

backends/nxp/tests/ir/converter/node_converter/test_cat_converter.py

@@ -290,3 +290,46 @@ def test_cat__force_delegate():
         graph=quantized_program.graph, ops=[exir_ops.edge.aten.cat.default]
     )
     assert any("lowered_module" in node.name for node in quantized_program.graph.nodes)
+
+
+def test_cat__same_shapes_converter_padding_last_dimension():
+    target = "imxrt700"
+
+    # The Converter is capable of padding the last dimension of `cat` with the same input shapes.
+    input_shape = (3, 1, 3)
+
+    quantized_program = to_quantized_edge_program(
+        CatModule(2),
+        [input_shape, input_shape],
+        target=target,
+        neutron_converter_flavor="SDK_25_09",
+        custom_delegation_options=CustomDelegationOptions(),
+    ).exported_program()
+
+    # Make sure the `Cat` was delegated.
+    assert not graph_contains_any_of_ops(
+        graph=quantized_program.graph, ops=[exir_ops.edge.aten.cat.default]
+    )
+    assert any("lowered_module" in node.name for node in quantized_program.graph.nodes)
+
+
+def test_cat__same_shapes_converter_padding_middle_dimension():
+    target = "imxrt700"
+
+    # The Converter is not capable of padding the middle dimensions of `cat` with the same input shapes.
+    input_shape = (3, 1, 3)
+
+    quantized_program = to_quantized_edge_program(
+        CatModule(1),
+        [input_shape, input_shape],
+        target=target,
+        custom_delegation_options=CustomDelegationOptions(),
+    ).exported_program()
+
+    # Make sure the `Cat` was NOT delegated.
+    assert graph_contains_any_of_ops(
+        graph=quantized_program.graph, ops=[exir_ops.edge.aten.cat.default]
+    )
+    assert not any(
+        "lowered_module" in node.name for node in quantized_program.graph.nodes
+    )