[Test] add MNIST top-1 accuracy measurement using stitched rtlsim

docker/Dockerfile.finn_ci

@@ -65,6 +65,7 @@ RUN apt update; apt install nano
 RUN pip install pytest-dependency
 RUN pip install pytest-xdist
 RUN pip install pytest-parallel
+RUN pip install mnist
 
 ENV PYTHONPATH "${PYTHONPATH}:/workspace/finn/src"
 ENV PYTHONPATH "${PYTHONPATH}:/workspace/pyverilator"

docker/Dockerfile.finn_dev

@@ -63,6 +63,7 @@ RUN pip install sphinx_rtd_theme==0.5.0
 RUN pip install pytest-xdist==2.0.0
 RUN pip install pytest-parallel==0.1.0
 RUN pip install netron==4.4.7
+RUN pip install mnist
 
 # switch user
 RUN groupadd -g $GID $GNAME

tests/end2end/test_end2end_bnn_pynq.py

@@ -92,11 +92,14 @@ from finn.util.pytorch import ToTensor
 from finn.transformation.merge_onnx_models import MergeONNXModels
 from finn.transformation.insert_topk import InsertTopK
 from finn.core.datatype import DataType
+import mnist
 
 build_dir = "/tmp/" + os.environ["FINN_INST_NAME"]
 target_clk_ns = 10
 mem_mode = "decoupled"
 rtlsim_trace = False
+mnist_test_imgs = mnist.test_images()
+mnist_test_labels = mnist.test_labels()
 
 
 def get_checkpoint_name(topology, wbits, abits, step):
@@ -393,6 +396,31 @@ class TestEnd2End:
         warnings.warn("Estimated & rtlsim performance: " + str(perf))
         assert np.isclose(y, output_tensor_npy).all()
 
+    @pytest.mark.slow
+    @pytest.mark.parametrize("kind", ["zynq"])
+    def test_rtlsim_top1(self, topology, wbits, abits, kind):
+        if "fc" not in topology:
+            pytest.skip("Top-1 rtlsim test currently for MNIST only")
+        rtlsim_chkpt = get_checkpoint_name(
+            topology, wbits, abits, "ipstitch_rtlsim_" + kind
+        )
+        parent_chkpt = get_checkpoint_name(topology, wbits, abits, "dataflow_parent")
+        load_test_checkpoint_or_skip(rtlsim_chkpt)
+        ok = 0
+        nok = 0
+        for i in range(10000):
+            tdata = mnist_test_imgs[i].reshape(1, 1, 28, 28).astype(np.float32)
+            exp = mnist_test_labels[i].item()
+            y = execute_parent(parent_chkpt, rtlsim_chkpt, tdata)
+            ret = y.item()
+            if ret == exp:
+                ok += 1
+            else:
+                nok += 1
+        acc_top1 = ok * 100.0 / (ok + nok)
+        warnings.warn("Final OK %d NOK %d top-1 %f" % (ok, nok, acc_top1))
+        assert acc_top1 > 90.0
+
     @pytest.mark.slow
     @pytest.mark.vivado
     @pytest.mark.parametrize("kind", ["zynq", "alveo"])