增加aten::sum op (#669)

* fix directly_map, Eltwise and crop

* add aten::sum op

* delet useless info

x2paddle/op_mapper/pytorch2paddle/aten.py

@@ -32,6 +32,45 @@ dtype_dict = {
 }
 
 
+def aten_sum(mapper, graph, node):
+    """ 构造获取元素求和的paddlelayer。
+    TorchScript示例:
+        %x_gap.15 : Tensor =  aten::sum(%x.58, %2166, %1450, %1453)
+        参数含义:
+        %x_gap.15 (Tensor): 求和后的Tensor。
+        %n.3 (Tensor): 求和前的Tensor。
+        %2166：axis
+        %1450：keepdim
+        %1453：dtype
+    """
+    scope_name = mapper.normalize_scope_name(node)
+    output_name = mapper._get_outputs_name(node)[0]
+    layer_outputs = [output_name]
+    layer_inputs = {}
+    layer_attrs = {}
+    inputs_name, inputs_node = mapper._get_inputs_name(node)
+    # 获取当前节点输出的list
+    current_outputs = [output_name]
+    # 处理输入0，即%n.3
+    mapper._check_input(graph, inputs_node[0], inputs_name[0], current_outputs,
+                        scope_name)
+    layer_inputs["x"] = inputs_name[0]
+    # 获取当前节点输入的list
+    current_inputs = list(layer_inputs.values())
+    if inputs_name[1] in mapper.attrs:
+        layer_attrs["axis"] = mapper.attrs[inputs_name[1]]
+    if inputs_name[2] in mapper.attrs:
+        layer_attrs["keepdim"] = mapper.attrs[inputs_name[2]]
+    if inputs_name[3] in mapper.attrs:
+        layer_attrs["dtype"] = mapper.attrs[inputs_name[3]]
+    graph.add_layer(
+        "paddle.sum",
+        inputs=layer_inputs,
+        outputs=layer_outputs,
+        scope_name=scope_name,
+        **layer_attrs)
+    return current_inputs, current_outputs
+
 def aten_abs(mapper, graph, node):
     """ 构造获取绝对值的PaddleLayer。
     TorchScript示例: