Arm backend: Convert assert to throw ValueError in op_exp

Asserts are converted to proper raises to ensure graph integrity.

It should not be possible for exp to have more than 1 input for a
correctly formatted graph, but in the node visitor we cannot know for
sure that the graph is formatted correctly.

torch.exp supports more data types than fp32, which is why it should be
checked.

Change-Id: I43ec2aa6bed20c871cd1a0f8d97ab12accc29533
Signed-off-by: Sebastian Larsson <[email protected]>

Author: Sebastian-Larsson

backends/arm/operators/op_exp.py

@@ -36,7 +36,14 @@ def define_node(
         output: TosaArg,
     ) -> None:
 
-        assert len(node.all_input_nodes) == 1
-        assert inputs[0].dtype == output.dtype == ts.DType.FP32
+        if len(node.all_input_nodes) != 1:
+            raise ValueError(
+                f"Expected 1 input for {self.target}, got {len(node.all_input_nodes)}"
+            )
+        if inputs[0].dtype != ts.DType.FP32 or output.dtype != ts.DType.FP32:
+            raise ValueError(
+                f"Input and output for {self.target} need to be FP32, got input dtype: "
+                f"{inputs[0].dtype} and output dtype: {output.dtype}"
+            )
 
         tosa_graph.addOperator(TosaOp.Op().EXP, [inputs[0].name], [output.name])