[Transformation] Added trafo to set "sim_mode" attribute

src/finn/transformation/fpgadataflow/set_sim_mode.py

+import finn.core.utils as util
+import finn.custom_op.registry as registry
+from finn.transformation import Transformation
+
+
+class SetSimMode(Transformation):
+    """Set attribute sim_mode in all fpgadataflow nodes"""
+
+    def __init__(self, mode):
+        super().__init__()
+        self.mode = mode
+
+    def apply(self, model):
+        for node in model.graph.node:
+            op_type = node.op_type
+            if node.domain == "finn":
+                backend_attribute = util.get_by_name(node.attribute, "backend")
+                if backend_attribute is None:
+                    continue
+                backend_value = backend_attribute.s.decode("UTF-8")
+                if backend_value == "fpgadataflow":
+                    try:
+                        # lookup op_type in registry of CustomOps
+                        inst = registry.custom_op[op_type](node)
+                        # set sim_mode accordingly to argument mode
+                        inst.set_nodeattr("sim_mode", self.mode)
+                        # ensure that sim_mode is now set
+                        assert inst.get_nodeattr("sim_mode") != ""
+                    except KeyError:
+                        # exception if op_type is not supported
+                        raise Exception(
+                            "Custom op_type %s is currently not supported." % op_type
+                        )
+        return (model, False)