fixed Flatten

x2paddle/op_mapper/onnx2paddle/opset9/opset.py

@@ -1627,11 +1627,15 @@ class OpSet9():
         val_x = self.graph.get_input_node(node, idx=0, copy=True)
         output_shape = val_x.out_shapes[0]
         axis = node.get_attr('axis', 1)
-        shape_list = [1, 1]
         if axis == 0:
-            for s in output_shape:
-                shape_list[1] *= s
+            self.paddle_graph.add_layer(
+                'paddle.reshape',
+                inputs={"x": val_x.name},
+                outputs=[node.name],
+                shape=[1, -1])
         else:
+            if len(output_shape) != 0:
+                shape_list = [1, 1]
                 for s in output_shape[:axis]:
                     shape_list[0] *= s
                 for s in output_shape[axis:]:
@@ -1641,6 +1645,48 @@ class OpSet9():
                     inputs={"x": val_x.name},
                     outputs=[node.name],
                     shape=shape_list)
+            else:
+                self.paddle_graph.add_layer(
+                    'paddle.shape',
+                    inputs={"input": val_x.name},
+                    outputs=[val_x.name + "_shape"])
+                self.paddle_graph.add_layer(
+                    "paddle.slice",
+                    inputs={"input": val_x.name + "_shape"},
+                    outputs=[val_x.name + "_shape_first"],
+                    axes=[0],
+                    starts=[0],
+                    ends=[axis])
+                self.paddle_graph.add_layer(
+                    'paddle.prod',
+                    inputs={"x": val_x.name + "_shape_first"},
+                    outputs=[val_x.name + "_shape_first"])
+                self.paddle_graph.add_layer(
+                    "paddle.slice",
+                    inputs={"input": val_x.name + "_shape"},
+                    outputs=[val_x.name + "_shape_second"],
+                    axes=[0],
+                    starts=[axis],
+                    ends=[2147483647])
+                self.paddle_graph.add_layer(
+                    'paddle.prod',
+                    inputs={"x": val_x.name + "_shape_second"},
+                    outputs=[val_x.name + "_shape_second"])
+                self.paddle_graph.add_layer(
+                    'paddle.concat',
+                    inputs={
+                        "x": [
+                            val_x.name + "_shape_first",
+                            val_x.name + "_shape_second"
+                        ]
+                    },
+                    outputs=[val_x.name + "_all_shape"],
+                    axis=0)
+                self.paddle_graph.add_layer(
+                    'paddle.reshape',
+                    inputs={'x': val_x.name},
+                    outputs=[node.name],
+                    shape=val_x.name + "_all_shape")
 
     @print_mapping_info
     def Gemm(self, node):