[Test] add test_factor_out_mul_sign_magnitude

tests/test_factor_out_mul_sign_magnitude.py

+import numpy as np
+import onnx.helper as oh
+from onnx import TensorProto
+
+import finn.core.onnx_exec as ox
+import finn.transformation.infer_shapes as si
+import finn.transformation.streamline as tx
+from finn.core.modelwrapper import ModelWrapper
+
+
+def test_factor_out_mul_sign_magnitude():
+    top_in = oh.make_tensor_value_info("top_in", TensorProto.FLOAT, [1, 2])
+    mul_param = oh.make_tensor_value_info("mul_param", TensorProto.FLOAT, [1, 2])
+    top_out = oh.make_tensor_value_info("top_out", TensorProto.FLOAT, [1, 2])
+    modelproto = oh.make_model(
+        oh.make_graph(
+            name="test",
+            inputs=[top_in],
+            outputs=[top_out],
+            value_info=[mul_param],
+            nodes=[oh.make_node("Mul", ["top_in", "mul_param"], ["top_out"])],
+        )
+    )
+    model = ModelWrapper(modelproto)
+    model = model.transform_single(si.infer_shapes)
+    model.set_initializer("mul_param", np.asarray([[-1, 4]], dtype=np.float32))
+    new_model = model.transform_repeated(tx.factor_out_mul_sign_magnitude)
+    inp_dict = {"top_in": np.asarray([[-1.0, 1.0]], dtype=np.float32)}
+    assert ox.compare_execution(model, new_model, inp_dict)