[Test] add 2-bit cases to CNV streamlining

tests/transformation/streamline/test_streamline_cnv.py

@@ -44,9 +44,9 @@ from finn.transformation.double_to_single_float import DoubleToSingleFloat
 export_onnx_path = make_build_dir("test_streamline_cnv_")
 
 # act bits
-@pytest.mark.parametrize("abits", [1])
+@pytest.mark.parametrize("abits", [1, 2])
 # weight bits
-@pytest.mark.parametrize("wbits", [1])
+@pytest.mark.parametrize("wbits", [1, 2])
 # network topology / size
 @pytest.mark.parametrize("size", ["CNV"])
 def test_streamline_cnv(size, wbits, abits):
@@ -74,6 +74,7 @@ def test_streamline_cnv(size, wbits, abits):
     # model.save("orig_cnv.onnx")
     model = model.transform(Streamline())
     # model.save("streamlined_cnv.onnx")
+    assert len(model.graph.node) == 23
     produced_ctx = oxe.execute_onnx(model, input_dict, True)
     produced = produced_ctx[model.graph.output[0].name]
     assert np.isclose(expected, produced, atol=1e-3).all()