fix neg

x2paddle/op_mapper/onnx2paddle/opset9/opset.py

@@ -2000,8 +2000,25 @@ class OpSet9():
     @print_mapping_info
     def Neg(self, node):
         val_x = self.graph.get_input_node(node, idx=0, copy=True)
+        v0, v1, v2 = paddle.__version__.split('.')
+        if int(v0) >= 2 and int(v1) >= 2:
             self.paddle_graph.add_layer(
                 "paddle.neg", inputs={'x': val_x.name}, outputs=[node.name])
+        else:
+            val_y = node.name + "_y"
+            dtype = np.dtype(val_x.dtype)
+            self.paddle_graph.add_layer(
+                "paddle.full",
+                inputs={},
+                outputs=[val_y],
+                dtype=string(dtype),
+                shape=[1],
+                fill_value=-1)
+            self.paddle_graph.add_layer(
+                "paddle.multiply",
+                inputs={'x': val_x.name,
+                        'y': val_y},
+                outputs=[node.name])
 
     @print_mapping_info
     def SpaceToDepth(self, node):