diff --git a/onnx2fluid/README.md b/onnx2fluid/README.md
index 95e4ad41101a6280ef6137944e15027255321de5..946882437c1ce785650a6a25f2f487971bad0478 100644
--- a/onnx2fluid/README.md
+++ b/onnx2fluid/README.md
@@ -54,7 +54,7 @@ onnx2fluid sample_1.onnx -t sample_1.npz
 onnx2fluid:
 
 ```shell
-onnx2fluid [-dexy] [-o /path/to/export_dir/] [-z archive.zip] [-t test_data.npz] /path/to/onnx/model.onnx
+onnx2fluid [-dexy] [-o /path/to/export_dir/] [-z archive.zip] [-t test_data.npz] [-i [input_name1,input_name2]] /path/to/onnx/model.onnx
 
 optional arguments:
   --debug, -d           启用调试
@@ -65,6 +65,8 @@ optional arguments:
   --output_dir, -o      指定输出目录
   --archive [ARCHIVE], -z [ARCHIVE]
                         如果验证通过，打包到指定的ZIP文件
+  --infer_inputs, -i [input_name1,input_name2]
+                        调用PaddlePaddle fluid类形推导完善模型
 ```
 
 转换工具onnx2fluid.conversion:
@@ -76,7 +78,7 @@ onnx2fluid.conversion [-dexy] [-o /path/to/export_dir/] /path/to/onnx/model.onnx
 验证工具onnx2fluid.validate:
 
 ```shell
-onnx2fluid.validate [-d] [-t test_data.npz] [-p 1e-3] /path/to/onnx/model.onnx
+onnx2fluid.validate [-d] [-t test_data.npz] [-i [input_name1,input_name2]] [-p 1e-3] /path/to/onnx/model.onnx
 ```
 
 ## 参考
diff --git a/onnx2fluid/README_en.md b/onnx2fluid/README_en.md
index 80259608d1737911da2d4ecad683d28897b57856..2a8782282a130b639d950ad3ac6ec176fab070cf 100644
--- a/onnx2fluid/README_en.md
+++ b/onnx2fluid/README_en.md
@@ -19,8 +19,8 @@ PyTorch to Paddlepaddle model conversion can be easily achieved with PyTorch ONN
 ## Environment and dependency
 
 * python 3.5+ (python 2 not fully supported yet)
-* onnx == 1.4.0
-* paddlepaddle == 1.3.0 (optional for validation)
+* onnx >= 1.4
+* paddlepaddle >= 1.3.0 (optional for validation)
 
 ## Get started
 
@@ -47,10 +47,12 @@ onnx2fluid sample_unet.onnx -t sample_unet.npz
 
 ## Usage
 
+**ONNX opset 9+** is mainly supported, corresponded to PyTorch **1.0/1.1(stable opset)**，for more information: [ONNX doc](https://github.com/onnx/onnx/blob/master/docs/Operators.md)
+
 onnx2fluid (all in one):
 
 ```shell
-onnx2fluid [-dexy] [-o /path/to/export_dir/] [-z archive.zip] [-t test_data.npz] /path/to/onnx/model.onnx
+onnx2fluid [-dexy] [-o /path/to/export_dir/] [-z archive.zip] [-t test_data.npz] [-i [input_name1,input_name2]] /path/to/onnx/model.onnx
 
 optional arguments:
   --debug, -d           enable debug logging and checking
@@ -61,6 +63,8 @@ optional arguments:
   --output_dir, -o      output directory
   --archive [ARCHIVE], -z [ARCHIVE]
                         compress outputs to ZIP file if conversion successed
+  --infer_inputs, -i [input_name1,input_name2]
+                        invoke PaddlePaddle fluid type-shape inference
 ```
 
 onnx2fluid.conversion:
@@ -72,10 +76,10 @@ onnx2fluid.conversion [-dexy] [-o /path/to/export_dir/] /path/to/onnx/model.onnx
 onnx2fluid.validate:
 
 ```shell
-onnx2fluid.validate [-d] [-t test_data.npz] [-p 1e-3] /path/to/onnx/model.onnx
+onnx2fluid.validate [-d] [-t test_data.npz] [-i [input_name1,input_name2]] [-p 1e-3] /path/to/onnx/model.onnx
 ```
 
 ## Reference
 
-* [PaddlePaddle fluid operators](http://www.paddlepaddle.org/documentation/docs/en/1.4/api/layers.html)
-* load converted model via [load_inference_model](http://www.paddlepaddle.org/documentation/docs/en/1.4/api/io.html#permalink-1-load_inference_model)
+* [PaddlePaddle fluid operators](http://www.paddlepaddle.org/documentation/docs/en/1.5/api/layers.html)
+* load converted model via [load_inference_model](http://www.paddlepaddle.org/documentation/docs/en/1.5/api/io.html#permalink-1-load_inference_model)
diff --git a/onnx2fluid/examples/convert_data_npz_0.py b/onnx2fluid/examples/convert_data_npz_0.py
deleted file mode 100644
index bd23f527a2f33981496aff1569be0ecfa5b77141..0000000000000000000000000000000000000000
--- a/onnx2fluid/examples/convert_data_npz_0.py
+++ /dev/null
@@ -1,48 +0,0 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
-"""
-Created on Wed Mar 27 11:50:03 2019
-
-@author: Macrobull
-"""
-
-import sys
-import numpy as np
-
-from collections import OrderedDict as Dict
-
-
-def _make_var_name(name):
-    """
-    make a valid variable name in Python code
-    """
-
-    if name == '':
-        return '_'
-    if name[0].isdigit():
-        return 'var_' + name
-    for s in ' *?\\/-:':
-        name = name.replace(s, '_')
-    if name.startswith('_'):
-        name = 'var' + name
-    return name
-
-
-fn = sys.argv[1]
-input_names = sys.argv[2].split(':')
-output_name = sys.argv[3].split(':')
-squeeze_data = len(sys.argv) > 4
-
-data = np.load(fn, encoding='bytes')
-input_data = data['inputs']
-output_data = data['outputs']
-
-while squeeze_data and input_data.ndim > 4 and input_data.shape[0] == 1:
-    input_data = input_data.squeeze(0)
-while squeeze_data and output_data.ndim > 2 and output_data.shape[0] == 1:
-    output_data = output_data.squeeze(0)
-
-inputs = Dict(zip(map(_make_var_name, input_names), [input_data]))
-outputs = Dict(zip(map(_make_var_name, output_name), [output_data]))
-
-np.savez(fn, inputs=inputs, outputs=outputs)  # overwrite
diff --git a/onnx2fluid/examples/convert_data_pb_0.py b/onnx2fluid/examples/convert_data_pb_0.py
deleted file mode 100644
index 78bac77ae5c8094edf7a833251ec878c776a18f5..0000000000000000000000000000000000000000
--- a/onnx2fluid/examples/convert_data_pb_0.py
+++ /dev/null
@@ -1,64 +0,0 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
-"""
-Created on Wed Mar 27 11:50:03 2019
-
-@author: Macrobull
-"""
-
-import os, sys
-import numpy as np
-import onnx
-import onnx.numpy_helper as numpy_helper
-
-from collections import OrderedDict as Dict
-from glob import glob
-
-
-def _make_var_name(name):
-    """
-    make a valid variable name in Python code
-    """
-
-    if name == '':
-        return '_'
-    if name[0].isdigit():
-        return 'var_' + name
-    for s in ' *?\\/-:':
-        name = name.replace(s, '_')
-    if name.startswith('_'):
-        name = 'var' + name
-    return name
-
-
-data_dir = os.path.dirname(sys.argv[1])
-input_names = sys.argv[2].split(':')
-output_name = sys.argv[3].split(':')
-squeeze_data = len(sys.argv) > 4
-
-# Load inputs
-inputs = []
-for fn in glob(os.path.join(data_dir, 'input_*.pb')):
-    tensor = onnx.TensorProto()
-    with open(fn, 'rb') as f:
-        tensor.ParseFromString(f.read())
-    tensor = numpy_helper.to_array(tensor)
-    while squeeze_data and tensor.ndim > 4 and tensor.shape[0] == 1:
-        tensor = tensor.squeeze(0)
-    inputs.append(tensor)
-
-# Load outputs
-outputs = []
-for fn in glob(os.path.join(data_dir, 'output_*.pb')):
-    tensor = onnx.TensorProto()
-    with open(fn, 'rb') as f:
-        tensor.ParseFromString(f.read())
-    tensor = numpy_helper.to_array(tensor)
-    while squeeze_data and tensor.ndim > 2 and tensor.shape[0] == 1:
-        tensor = tensor.squeeze(0)
-    outputs.append(tensor)
-
-inputs = Dict(zip(map(_make_var_name, input_names), inputs))
-outputs = Dict(zip(map(_make_var_name, output_name), outputs))
-
-np.savez(data_dir, inputs=inputs, outputs=outputs)
diff --git a/onnx2fluid/examples/gen_some_samples.py b/onnx2fluid/examples/gen_some_samples.py
index 52aacefeba70ef9705f02e3c5ce37247693b43f3..01ec25facc518b1f1e78c69094d6d3db1d84b7a9 100644
--- a/onnx2fluid/examples/gen_some_samples.py
+++ b/onnx2fluid/examples/gen_some_samples.py
@@ -20,34 +20,74 @@ from onnx2fluid.torch_export_helper import export_onnx_with_validation
 prefix = 'sample_'
 idx = 0
 
+######## example: RNN cell ########
+
+
+class Model(nn.Module):
+    def __init__(self):
+        super(Model, self).__init__()
+        self.gru = nn.GRUCell(6, 5)
+        self.lstm = nn.LSTMCell(5, 4)
+
+    def forward(self, x, h1, h2, c2):
+        h = self.gru(x, h1)
+        h, c = self.lstm(h, (h2, c2))
+        return h, c
+
+
+model = Model()
+model.eval()
+xb = torch.rand((7, 6))
+h1 = torch.zeros((7, 5))
+h2 = torch.zeros((7, 4))
+c2 = torch.zeros((7, 4))
+yp = model(xb, h1, h2, c2)
+idx += 1
+print('index: ', idx)
+export_onnx_with_validation(model, [xb, h1, h2, c2],
+                            prefix + str(idx), ['x', 'h1', 'h2', 'c2'],
+                            ['h', 'c'],
+                            verbose=True,
+                            training=False)
+
 ######## example: RNN ########
 
 
 class Model(nn.Module):
     def __init__(self):
         super(Model, self).__init__()
-        self.gru = nn.GRU(4, 5, 3)
-        self.lstm = nn.LSTM(5, 6, 2)
+        self.gru = nn.GRU(6, 5, 3)
+        self.lstm = nn.LSTM(5, 4, 2)
 
-    def forward(self, x):
-        y = x
-        y, h = self.gru(y)
-        y, h = self.lstm(y)
+    def forward(self, x, h1, h2, c2):
+        y, h1 = self.gru(x, h1)
+        y, (h2, c2) = self.lstm(y, (h2, c2))
         return y
 
 
 model = Model()
 model.eval()
-xb = torch.rand((2, 3, 4))
-yp = model(xb)
+xb = torch.rand((8, 1, 6))
+h1 = torch.zeros((3, 1, 5))
+h2 = torch.zeros((2, 1, 4))
+c2 = torch.zeros((2, 1, 4))
+yp = model(xb, h1, h2, c2)
 idx += 1
 print('index: ', idx)
-export_onnx_with_validation(model, [xb],
-                            prefix + str(idx), ['x'], ['y'],
+export_onnx_with_validation(model, [xb, h1, h2, c2],
+                            prefix + str(idx), ['x', 'h1', 'h2', 'c2'], ['y'],
                             verbose=True,
                             training=False)
 
 ######## example: random ########
+"""
+    symbolic registration:
+
+    def rand(g, *shapes):
+        shapes_list = list(shapes)
+        shape = _maybe_get_const(shapes_list[0], "is")
+        return g.op('RandomUniform', shape_i=shape)
+"""
 
 
 class Model(nn.Module):
@@ -55,8 +95,9 @@ class Model(nn.Module):
         super(Model, self).__init__()
 
     def forward(self, x):
-        y = torch.rand((2, 3))  # + torch.rand_like(xb)
-        y = y + torch.randn((2, 3))  # + torch.randn_like(xb)
+        y = torch.rand((2, 3))  # + torch.rand_like(x)
+        y = y + torch.randn((2, 3))  # + torch.randn_like(x)
+        y = y + x
         return y
 
 
@@ -124,6 +165,13 @@ export_onnx_with_validation(model, [xb0, xb1],
                             training=False)
 
 ######## example: affine_grid ########
+"""
+    symbolic registration:
+
+    @parse_args('v', 'is')
+    def affine_grid_generator(g, theta, size):
+        return g.op('AffineGrid', theta, size_i=size)
+"""
 
 
 class Model(nn.Module):
diff --git a/onnx2fluid/onnx2fluid/cmdline.py b/onnx2fluid/onnx2fluid/cmdline.py
index 4294490224a4762301d102a2b6b45970cbb5fcf5..14753ace9d3af3e71ce3a145a663cfc6028e8077 100644
--- a/onnx2fluid/onnx2fluid/cmdline.py
+++ b/onnx2fluid/onnx2fluid/cmdline.py
@@ -61,7 +61,7 @@ def main(**kwargs):
     passed = True
     golden_data_filename = kwargs.pop('test_data', '')
     infer_inputs = kwargs.pop('infer_inputs', None)
-    if golden_data_filename or infer_inputs:
+    if golden_data_filename or infer_inputs is not None:
         from .validation import validate
 
         save_inference_model = infer_inputs is not None
diff --git a/onnx2fluid/onnx2fluid/conversion.py b/onnx2fluid/onnx2fluid/conversion.py
index a7fee9cd45bf8c1220bdcb520623bd64a8d147bd..336dac4fb2641db39b4ebb690f07d708b4755140 100644
--- a/onnx2fluid/onnx2fluid/conversion.py
+++ b/onnx2fluid/onnx2fluid/conversion.py
@@ -91,7 +91,7 @@ def convert(onnx_model_filename,
     # onnx model optimization
     logger.info('model has %d ops', len(onnx_model.graph.node))
     logger.info('optimizing model ...')
-    onnx_model = polish_model(onnx_model)
+    onnx_model = polish_model(onnx_model, checking=onnx_opset_pedantic)
 
     # prepare filesystem
     shutil.rmtree(save_dir, ignore_errors=True)
@@ -123,6 +123,7 @@ def convert(onnx_model_filename,
     for name, weight in graph_weights(onnx_graph):
         var_name = make_var_name(name)
         value_info = value_infos[var_name]
+        value_info['lod'] = [0]
         value_info['embedded_as'] = []
         value_info['get_weight'] = (lambda w: lambda: w.tolist())(
             weight)  # lazy getter
@@ -134,8 +135,8 @@ def convert(onnx_model_filename,
     for name, domain, op_type, inputs, outputs, attrs in graph_ops(onnx_graph,
                                                                    topo=topo):
         op_name = make_var_name(name)
-        inputs = [make_var_name(val) for val in inputs]
-        outputs = [make_var_name(val) for val in outputs]
+        inputs = list(map(make_var_name, inputs))
+        outputs = list(map(make_var_name, outputs))
         logger.debug('translating op %s(%s) %s::%s ...', name, op_name, domain,
                      op_type)
         if domain == DEFAULT_OP_DOMAIN:
@@ -192,13 +193,16 @@ def convert(onnx_model_filename,
                          weight.dtype, weight.size, weight.nbytes,
                          embedded_names)
             for embedded_name in embedded_names:  # multiple references
-                fluid_writer.write_weight(
-                    weight, shutil.os.path.join(save_dir, embedded_name))
+                fluid_writer.write_weight(weight,
+                                          shutil.os.path.join(
+                                              save_dir, embedded_name),
+                                          lod=value_info['lod'])
         else:
             logger.debug('saving weight %s(%s[%d], %dB) to %s ...', name,
                          weight.dtype, weight.size, weight.nbytes, var_name)
             fluid_writer.write_weight(weight,
-                                      shutil.os.path.join(save_dir, var_name))
+                                      shutil.os.path.join(save_dir, var_name),
+                                      lod=value_info['lod'])
         fluid_writer.emit_param(fluid_program, var_name, value_info)
     param_codes = fluid_program.codes
     fluid_program.codes = []
diff --git a/onnx2fluid/onnx2fluid/onnx_utils.py b/onnx2fluid/onnx2fluid/onnx_utils.py
index e8b5a472e312439f97606c02e5cc4f7f657ce4c2..f738a537b5225c16868c3e5bb3f550fb0ea971fb 100644
--- a/onnx2fluid/onnx2fluid/onnx_utils.py
+++ b/onnx2fluid/onnx2fluid/onnx_utils.py
@@ -319,17 +319,20 @@ def skip_node_backward(nodes, src_input_name, dst_output_name, output_refs):
     return processed
 
 
-def polish_model(model, extras=True):
+def polish_model(model, internals=True, extras=True, checking=True):
     """
     polish_model enhanced for inference
     """
 
-    check_model(model)
+    if checking:
+        check_model(model)
     strip_doc_string(model)
-    passes = optimizer.get_available_passes()
-    passes = list(filter(lambda name: not name.startswith('split_'), passes))  #
-    logger.debug('builtin optimizations to perform in ONNX:\n\t%s', passes)
-    model = optimizer.optimize(model, passes=passes)
+    if internals:
+        passes = optimizer.get_available_passes()
+        passes = list(filter(lambda name: not name.startswith('split_'),
+                             passes))  #
+        logger.debug('builtin optimizations to perform in ONNX:\n\t%s', passes)
+        model = optimizer.optimize(model, passes=passes)
     if extras:
         for optimize in (
                 optimize_model_skip_op_for_inference,
@@ -339,7 +342,8 @@ def polish_model(model, extras=True):
         ):
             model = optimize(model)
     model = infer_shapes(model)
-    check_model(model)
+    if checking:
+        check_model(model)
     return model
 
 
diff --git a/onnx2fluid/onnx2fluid/symbolic.py b/onnx2fluid/onnx2fluid/symbolic.py
index 139d3bcef96159e275373def886ae7e4f37b3c7f..d5f1167be9135c81642c871983e6b3259a8e55d9 100644
--- a/onnx2fluid/onnx2fluid/symbolic.py
+++ b/onnx2fluid/onnx2fluid/symbolic.py
@@ -44,10 +44,10 @@ DEFAULT_OP_MAPPING = {
         ## nil ops ##
         'RandomUniform':
             ['uniform_random', [], ['Out'], dict(high='max', low='min'),
-             dict(), None, None, False],
+             dict(), None, None, False], # TODO: add dtype support
         'RandomNormal':
             ['gaussian_random', [], ['Out'], dict(scale='std'),
-             dict(), None, None, False],
+             dict(), None, None, False], # TODO: add dtype support
         ## unary ops ##
         'Abs': ['abs', ['X'], ['Out']],
         'Acos': ['acos', ['X'], ['Out']],
@@ -63,21 +63,27 @@ DEFAULT_OP_MAPPING = {
         'Flatten': ['flatten', ['X'], ['Out']], # attrs bypassed, FIXME: emit flatten2
         'Floor': ['floor', ['X'], ['Out']],
         'Gather': ['gather', ['X'], ['Out'], dict(axis='')],
+        'HardSigmoid': ['hard_sigmoid', ['X'], ['Out'], dict(alpha='slope', beta='offset')],
+        'Identity': ['assign', ['X'], ['Out']],
         'LeakyRelu': ['leaky_relu', ['X'], ['Out']],
         'Log': ['log', ['X'], ['Out']],
         'LRN': ['lrn', ['X'], ['Out', 'MidOut'], dict(size='n', bias='k')], #
         'Reciprocal': ['reciprocal', ['X'], ['Out']],
         'Relu': ['relu', ['X'], ['Out']],
+        'Round': ['round', ['X'], ['Out']],
         'Selu': ['selu', ['X'], ['Out'], dict(gamma='scale')],
         'Shape': ['shape', ['X'], ['Out']], # FIXME: out is int64 vs int32
         'Shrink': ['softshrink', ['X'], ['Out'], dict(bias='', labmd='')],
         'Sigmoid': ['sigmoid', ['X'], ['Out']],
+        'Sign': ['sign', ['X'], ['Out']],
         'Sin': ['sin', ['X'], ['Out']],
         'Squeeze': ['squeeze', ['X'], ['Out']], # attrs bypassed, FIXME: emit squeeze2
         'Softplus': ['softplus', ['X'], ['Out']],
         # FIXME: default axis = -1, reshape required before and after
         'Softmax': ['softmax', ['X'], ['Out'], dict(axis='')],
+        'Softplus': ['softplus', ['X'], ['Out']],
         'Softsign': ['softsign', ['X'], ['Out']],
+        'SpaceToDepth': ['space_to_depth', ['X'], ['Out']],
         'Sqrt': ['sqrt', ['X'], ['Out']],
         'Tanh': ['tanh', ['X'], ['Out']],
         'ThresholdedRelu': ['thresholded_relu', ['X'], ['Out'], dict(alpha='threshold')],
@@ -94,6 +100,7 @@ DEFAULT_OP_MAPPING = {
         'MatMul': ['matmul', ['X', 'Y'], ['Out']], # defaults excluded for transpose_x vs transpose_X
         'Max': ['elementwise_max', ['X', 'Y'], ['Out'], dict(), dict(axis=-1)],
         'Min': ['elementwise_min', ['X', 'Y'], ['Out'], dict(), dict(axis=-1)],
+        'Mod': ['elementwise_mod', ['X', 'Y'], ['Out'], dict(), dict(axis=-1)],
         'Mul': ['elementwise_mul', ['X', 'Y'], ['Out'], dict(), dict(axis=-1)],
         'Not': ['logical_not', ['X', 'Y'], ['Out']],
         'OneHot': # assuming values=[0, 1], axis=-1 and drop them
@@ -117,32 +124,30 @@ DEFAULT_OP_MAPPING = {
 DEFAULT_IOA_CONSTRAINTS = {
     'ArgMax': [
         (lambda i, o, a: a.get('keepdims', 1) == 1,
-         'only keepdims = 0 is supported'),
+         'only keepdims = 0 supported'),
     ],
     'ArgMin': [
         (lambda i, o, a: a.get('keepdims', 1) == 1,
-         'only keepdims = 0 is supported'),
+         'only keepdims = 0 supported'),
     ],
     'Gather': [
-        (lambda i, o, a: a.get('axis', 0) == 0, 'only axis = 0 is supported'),
+        (lambda i, o, a: a.get('axis', 0) == 0, 'only axis = 0 supported'),
     ],
     'Shrink': [
         (lambda i, o, a: a.get('bias', 0) == a.get('lambd', 0.5),
-         'only SoftShrink with bias = lambd is supported'),
+         'only SoftShrink with bias = lambd supported'),
     ],
     #        'Softmax':
     #            [(lambda i, o, a: a.get('axis', 1) == -2, 'Paddle fluid Softmax works on dim -2 only'),
     #            ],
     'OneHot': [
-        (lambda i, o, a: a.get('axis', -1) == -1,
-         'only axis = -1 is supported'),
+        (lambda i, o, a: a.get('axis', -1) == -1, 'only axis = -1 supported'),
     ],
     'Scatter': [
-        (lambda i, o, a: a.get('axis', 0) == 0, 'only axis = 0 is supported'),
+        (lambda i, o, a: a.get('axis', 0) == 0, 'only axis = 0 supported'),
     ],
     'TopK': [
-        (lambda i, o, a: a.get('axis', -1) == -1,
-         'only axis = -1 is supported'),
+        (lambda i, o, a: a.get('axis', -1) == -1, 'only axis = -1 supported'),
     ],
 }
 
@@ -226,10 +231,10 @@ def _default(prog, op_type, inputs, outputs, attrs, *args, name='', **kwargs):
     fluid_attrs = default_attrs.copy()
     fluid_attrs.update(mapped_attrs)  # as new attrs
 
-    var_inps = inputs if input_perm is None else list(
-        map(inputs.__getitem__, input_perm))
-    var_outs = outputs if output_perm is None else list(
-        map(outputs.__getitem__, output_perm))
+    var_inps = list(map(inputs.__getitem__,
+                        input_perm)) if input_perm else inputs
+    var_outs = list(map(outputs.__getitem__,
+                        output_perm)) if output_perm else outputs
     arg_name = ', name={}'.format(
         repr(name)) if fill_name_field and name else ''
     arg_attrs = [
@@ -240,7 +245,7 @@ def _default(prog, op_type, inputs, outputs, attrs, *args, name='', **kwargs):
         ', '.join(var_outs),
         fluid_op,
         ', '.join(var_inps),
-        ''.join(arg_attrs),
+        ''.join(arg_attrs)[(0 if var_inps else 2):],
         arg_name,
     ))
 
@@ -255,8 +260,8 @@ def _default(prog, op_type, inputs, outputs, attrs, *args, name='', **kwargs):
 
     for var_out in var_outs:
         prog.VarDesc(var_out)
-    prog.OpDesc(fluid_op, (var_inps, *fluid_input_args),
-                (var_outs, *fluid_output_args), fluid_attrs)
+    prog.OpDesc(fluid_op, (fluid_input_args, var_inps),
+                (fluid_output_args, var_outs), fluid_attrs)
 
 
 def _assign(prog, mapping):
@@ -272,8 +277,8 @@ def _assign(prog, mapping):
         prog.VarDesc(var_dst)
         prog.OpDesc(
             fluid_op,
-            ([var_src], 'X'),
-            ([var_dst], 'Out'),
+            (['X'], [var_src]),
+            (['Out'], [var_dst]),
             dict(),
         )
 
@@ -289,7 +294,7 @@ def _zeros_like(prog, var_ref, var_out, value_infos):
     )
 
 
-def _pad_if_asymmetric(prog, pads, var_name, value_infos):  # pads: SSEE
+def _pad_if_asymmetric(prog, pads, var_input, value_infos):  # pads: SSEE
     assert len(pads) & 1 == 0
     ndims = len(pads) // 2
     symmetric = True
@@ -298,13 +303,13 @@ def _pad_if_asymmetric(prog, pads, var_name, value_infos):  # pads: SSEE
             symmetric = False
             break
     if symmetric:
-        return pads[:ndims], var_name
+        return pads[:ndims], var_input
 
-    var_padded = var_name + '_padded'  # explicit variable
+    var_padded = var_input + '_padded'  # explicit variable
     prog.Op(
         '',
         'Pad',
-        [var_name],
+        [var_input],
         [var_padded],
         {
             'mode': 'constant',
@@ -312,7 +317,7 @@ def _pad_if_asymmetric(prog, pads, var_name, value_infos):  # pads: SSEE
             'pads': pads,
         },
         value_infos=value_infos,
-        name=var_padded,
+        name=(var_input + '_pad'),
     )
     return [0] * ndims, var_padded
 
@@ -320,12 +325,12 @@ def _pad_if_asymmetric(prog, pads, var_name, value_infos):  # pads: SSEE
 def _adaptive_pool(prog, pool_type, inputs, outputs, attrs, name=''):
     # I/O
     var_x, = inputs
-    var_y, var_indices = (outputs + [None] * 1)[:2]
+    var_y, var_indices, = (outputs + [None] * 1)[:2]
 
     # interpretation
     pool_size = attrs['output_size']  # required
     poolnd = len(pool_size)
-    assert 2 <= poolnd <= 3, 'only pool2d and pool3d is supported'
+    assert 2 <= poolnd <= 3, 'only pool2d and pool3d supported'
 
     fluid_op = 'adaptive_pool{}d'.format(poolnd)
     name_attr = ', name={}'.format(repr(name)) if name else ''
@@ -352,15 +357,16 @@ def _adaptive_pool(prog, pool_type, inputs, outputs, attrs, name=''):
         prog.VarDesc(var_indices)
     prog.OpDesc(
         fluid_op,
-        ([var_x], 'X'),
-        ([var_y] + ([var_indices] if var_indices else []), 'Out', 'Indices'),
+        (['X'], [var_x]),
+        (['Out', 'Indices'], [var_y] + ([var_indices] if var_indices else [])),
         {
             'global_pooling': False,
             'adaptive': True,
-            'exclusive': True,
             'require_index': bool(var_indices),
             'pooling_type': pool_type,
             'ksize': pool_size,
+            # unused
+            #                    'exclusive': True,
         },
     )
 
@@ -378,7 +384,7 @@ def _global_pool(prog, pool_type, inputs, outputs, attrs, value_infos, name=''):
         poolnd = len(input_shape) - 2  # NC...
     elif output_shape is not None:
         poolnd = len(output_shape) - 2  # NC...
-    assert 2 <= poolnd <= 3, 'only pool2d and pool3d is supported'
+    assert 2 <= poolnd <= 3, 'only pool2d and pool3d supported'
 
     fluid_op = 'pool{}d'.format(poolnd)
     name_attr = ', name={}'.format(repr(name)) if name else ''
@@ -397,13 +403,17 @@ def _global_pool(prog, pool_type, inputs, outputs, attrs, value_infos, name=''):
     prog.VarDesc(var_y)
     prog.OpDesc(
         fluid_op,
-        ([var_x], 'X'),
-        ([var_y], 'Out'),
+        (['X'], [var_x]),
+        (['Out'], [var_y]),
         {
             'global_pooling': True,
             'adaptive': False,
             'pooling_type': pool_type,
             'ksize': [-1, -1],
+            # unused
+            'strides': [-1, -1],
+            'paddings': [0, 0],
+            'ceil_mode': False,
         },
     )
 
@@ -411,15 +421,17 @@ def _global_pool(prog, pool_type, inputs, outputs, attrs, value_infos, name=''):
 def _pool(prog, pool_type, inputs, outputs, attrs, value_infos, name=''):
     # I/O
     var_x, = inputs
-    var_y, var_indices = (outputs + [None] * 1)[:2]
+    var_y, var_indices, = (outputs + [None] * 1)[:2]
 
     # interpretation
     assert attrs.get(
         'auto_pad',
-        'NOTSET') == 'NOTSET', 'only auto_pad = NOTSET is supported'  # optional
+        'NOTSET') == 'NOTSET', 'only auto_pad = NOTSET supported'  # optional
+    assert attrs.get('count_include_pad',
+                     0) == 0, 'only count_include_pad = 0 supported'  # optional
     pool_size = attrs['kernel_shape']  # required
     poolnd = len(pool_size)
-    assert 2 <= poolnd <= 3, 'only pool2d and pool3d is supported'
+    assert 2 <= poolnd <= 3, 'only pool2d and pool3d supported'
 
     fluid_op = 'pool{}d'.format(poolnd)
     strides = attrs.get('strides', [1] * poolnd)  # optional
@@ -452,25 +464,26 @@ def _pool(prog, pool_type, inputs, outputs, attrs, value_infos, name=''):
         prog.VarDesc(var_indices)
     prog.OpDesc(
         fluid_op,
-        ([var_x], 'X'),
-        ([var_y] + ([var_indices] if var_indices else []), 'Out', 'Indices'),
+        (['X'], [var_x]),
+        (['Out', 'Indices'], [var_y] + ([var_indices] if var_indices else [])),
         {
             'global_pooling': False,
             'adaptive': False,
-            'exclusive': True,
             'require_index': bool(var_indices),
             'pooling_type': pool_type,
             'ksize': pool_size,
             'strides': strides,
             'paddings': paddings,
             'ceil_mode': ceil_mode,
+            # unused
+            'exclusive': True,
         },
     )
 
 
 def _roi_pool(prog, fluid_op, inputs, outputs, attrs, value_infos, name):
     # I/O
-    var_x, var_rois = inputs
+    var_x, var_rois, = inputs
     var_y, = outputs
 
     # interpretation
@@ -514,15 +527,15 @@ def _roi_pool(prog, fluid_op, inputs, outputs, attrs, value_infos, name):
         prog.VarDesc(var_argmax)
     prog.OpDesc(
         fluid_op,
-        ([var_x, var_rois], 'X', 'Rois'),
-        ([var_y] + ([var_argmax] if is_max_pool else []), 'Out', 'Argmax'),
+        (['X', 'Rois'], [var_x, var_rois]),
+        (['Out', 'Argmax'], [var_y] + ([var_argmax] if is_max_pool else [])),
         od_attrs,
     )
 
 
 def _interpolate(prog, inputs, outputs, attrs, value_infos, name=''):
     # I/O
-    var_x, var_scales = inputs
+    var_x, var_scales, = inputs
     var_y, = outputs
 
     # interpretation
@@ -542,7 +555,7 @@ def _interpolate(prog, inputs, outputs, attrs, value_infos, name=''):
     scale = scales and scales[2]
     # try input shape
     if scale is None:
-        assert out_shape_, 'neither scales nor output shape is available'
+        assert out_shape_, 'neither scales nor output shape available'
         out_shape = out_shape_
     else:
         out_shape = None
@@ -572,8 +585,8 @@ def _interpolate(prog, inputs, outputs, attrs, value_infos, name=''):
     prog.VarDesc(var_y)
     prog.OpDesc(
         fluid_op,
-        ([var_x], 'X'),
-        ([var_y], 'Out'),
+        (['X'], [var_x]),
+        (['Out'], [var_y]),
         {
             'interp_method': mode,
             'out_h ': out_shape_[0],
@@ -626,8 +639,8 @@ def AffineGrid(prog, inputs, outputs, attrs, *args, name='', **kwargs):
     prog.VarDesc(var_grid)
     prog.OpDesc(
         fluid_op,
-        ([var_theta], 'Theta'),
-        ([var_grid], 'Output'),
+        (['Theta'], [var_theta]),
+        (['Output'], [var_grid]),
         {'output_shape': size},  # f**k you API
     )
 
@@ -661,10 +674,14 @@ def BatchNormalization(prog,
     """
 
     # I/O
-    var_x, var_scale, var_b, var_mean, var_var = inputs
-    var_y, = outputs
-    var_saved_mean = name + '.saved_mean'  # dummy output
-    var_saved_variance = name + '.saved_variance'  # dummy output
+    var_x, var_scale, var_b, var_mean, var_var, = inputs
+    var_y, var_mean_, var_var_, var_saved_mean, var_saved_variance, = (
+        outputs + [None] * 4)[:5]
+    assert var_saved_mean or (name != '')
+    assert var_saved_variance or (name != '')
+    var_saved_mean = var_saved_mean or (name + '.saved_mean')  # dummy output
+    var_saved_variance = var_saved_variance or (name + '.saved_variance'
+                                                )  # dummy output
 
     # interpretation
     fluid_op = 'batch_norm'
@@ -700,7 +717,7 @@ def BatchNormalization(prog,
                           repr(var_var))
 
     # generation
-    prog.Code('{} = layers.{}({}, is_test=True, data_layout="NCHW"'
+    prog.Code('{} = layers.{}({}, is_test=True'
               ', momentum={}'
               ', epsilon={}'
               '{}{})'.format(
@@ -718,16 +735,15 @@ def BatchNormalization(prog,
     prog.VarDesc(var_saved_variance)
     prog.OpDesc(
         fluid_op,
-        ([var_x, var_scale, var_b, var_mean, var_var
-          ], 'X', 'Scale', 'Bias', 'Mean', 'Variance'),
-        ([var_y, var_mean, var_saved_mean, var_saved_variance, var_var
-          ], 'Y', 'MeanOut', 'SavedMean', 'SavedVariance', 'VarianceOut'),
+        (['X', 'Scale', 'Bias', 'Mean', 'Variance'
+          ], [var_x, var_scale, var_b, var_mean, var_var]),
+        (['Y', 'MeanOut', 'SavedMean', 'SavedVariance', 'VarianceOut'
+          ], [var_y, var_mean, var_saved_mean, var_saved_variance, var_var]),
         {
-            'is_test': 1,
-            'data_layout': 'NCHW',
-            'use_global_stats': False,
             'momentum': momentum,
             'epsilon': epsilon,
+            'is_test': 1,
+            # unused
         },
     )
 
@@ -745,9 +761,11 @@ def Cast(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
     dtype = attrs['to']  # required
     if not isinstance(dtype, _np.dtype):  # additional: possible np.dtype
         dtype = TENSOR_TYPE_TO_NP_TYPE[dtype]
-    output_dtype = _dtype_or_none(value_infos, var_output)
-    if output_dtype is not None:
-        assert dtype == output_dtype, 'dtype of to unmatches output'
+
+
+#    output_dtype = _dtype_or_none(value_infos, var_output)
+#    if output_dtype is not None:
+#        assert dtype == output_dtype, 'dtype of to unmatches output'
 
     fluid_op = 'cast'
 
@@ -764,8 +782,8 @@ def Cast(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
     prog.VarDesc(var_output)
     prog.OpDesc(
         fluid_op,
-        ([var_input], 'X'),
-        ([var_output], 'Out'),
+        (['X'], [var_input]),
+        (['Out'], [var_output]),
         {
             'in_dtype': prog.Dtype(_dtype(value_infos,
                                           var_input)),  # holy, required
@@ -801,8 +819,8 @@ def Concat(prog, inputs, outputs, attrs, *args, name='', **kwargs):
     prog.VarDesc(var_ret)
     prog.OpDesc(
         fluid_op,
-        (inputs, *(['X'] * len(inputs))),
-        ([var_ret], 'Out'),
+        (['X'] * len(inputs), inputs),
+        (['Out'], [var_ret]),
         {'axis': axis},
     )
 
@@ -819,13 +837,11 @@ def Constant(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
     # interpretation
     value = attrs['value']  # required
     dtype = _np.dtype(value.dtype)
-    output_dtype = _dtype_or_none(value_infos, var_output)
-    if output_dtype is not None:
-        assert dtype == output_dtype, 'tensor dtype unmatches storage dtype'
-
-
-#    dtype = _np.dtype('float32') # HINT: force to float32
-    shape = attrs.get('shape', None)  #
+    #    output_dtype = _dtype_or_none(value_infos, var_output)
+    #    if output_dtype is not None:
+    #        assert dtype == output_dtype, 'tensor dtype unmatches storage dtype'
+    #    dtype = _np.dtype('float32') # HINT: force to float32
+    shape = attrs.get('shape', None)  # additional
     if shape is None:
         shape = _shape_or_none(value_infos, var_output)
     if shape is None:
@@ -836,10 +852,9 @@ def Constant(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
             'using value as 1-D tensor may lead to fails', outputs, var_output)
 
     # generation
-    value = value.tolist()
-    if len(value) == 1:  # scalar
+    if len(shape) == 0 or value.size == 1:  # scalar or 1-size
         shape = [1]  # WORKAROUND: bad scalar support
-        value = value[0]
+        value = value.tolist()[0]
         fluid_op = 'fill_constant'
         prog.Code('{} = layers.{}(shape={}, dtype={}, value={})'.format(
             var_output,
@@ -852,8 +867,8 @@ def Constant(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
         prog.VarDesc(var_output)
         prog.OpDesc(
             fluid_op,
-            ([], ),
-            ([var_output], 'Out'),
+            ([], []),
+            (['Out'], [var_output]),
             {
                 'shape': shape,
                 'dtype': prog.Dtype(dtype),
@@ -862,7 +877,7 @@ def Constant(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
         )
     else:  # list parameter -> const_value
         prog.Code('# {} = {} # passed directly as literal'.format(
-            var_output, value))
+            var_output, value.tolist()))
 
     value_infos[var_output]['const_value'] = value
 
@@ -882,16 +897,16 @@ def ConstantOfShape(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
     assert shape is not None, (
         'given shape is neither const value nor deductible from output, '
         'this is not supported')
-    dtype = attrs['value'].dtype
     attrs = attrs.copy()
-    attrs.update({'shape': shape, 'dtype': dtype})  # pass const
+    attrs.setdefault('value', np.array(0, dtype=np.float32))
+    attrs.update({'shape': shape})  # pass const
 
     prog.Code('# shape:{}={} # const as literal'.format(var_shape, shape))
     prog.Op(
         '',
         'Constant',
         [],
-        outputs,  # val
+        outputs,
         attrs,
         value_infos,
     )
@@ -902,7 +917,7 @@ def Conv(prog,
          outputs,
          attrs,
          value_infos,
-         name='',
+         name,
          embed_params=False,
          *args,
          **kwargs):
@@ -911,18 +926,18 @@ def Conv(prog,
     """
 
     # I/O
-    var_x, var_w = inputs[:2]
-    var_y, var_b = (outputs + [None] * 1)[:2]
+    var_x, var_w, var_b, = (inputs + [None] * 1)[:3]
+    var_y, = outputs
 
     # interpretation
     assert attrs.get(
-        'auto_pad', 'NOTSET'
-    ) == 'NOTSET', 'only auto_pad == NOTSET is supported'  # optional
-    kernel_shape = _shape(value_infos, var_w)[2:]  # OI...
-    assert kernel_shape == attrs[
-        'kernel_shape'], 'kernel_shape in attr unmatches value_info'  # HW
+        'auto_pad',
+        'NOTSET') == 'NOTSET', 'only auto_pad = NOTSET supported'  # optional
+    kernel_shape = attrs.get('kernel_shape',
+                             _shape(value_infos, var_w)[2:])  # optional, HW
+    assert kernel_shape, 'kernel_shape not inferred'
     convnd = len(kernel_shape)
-    assert 2 <= convnd <= 3, 'only conv2d and conv3d is supported'
+    assert 2 <= convnd <= 3, 'only conv2d and conv3d supported'
     num_out_channels = _shape(value_infos, var_w)[0]  # OI...
 
     fluid_op = 'conv{}d'.format(convnd)
@@ -931,16 +946,15 @@ def Conv(prog,
     dilations = attrs.get('dilations', [1] * convnd)  # optional
     pads = attrs.get('pads', [0] * (convnd * 2))  # optional
     paddings, var_x = _pad_if_asymmetric(prog, pads, var_x, value_infos)
-    name_attr = ', name={}'.format(repr(name)) if name else ''
+    name_attr = ', name={}'.format(repr(name))
     if embed_params:
-        embed_params = (_check_embeddable(value_infos, var_w) and not var_b
-                        or _check_embeddable(value_infos, var_b))
-        if not embed_params and name:
+        embed_params = _check_embeddable(
+            value_infos, *([var_w] + ([var_b] if var_b else [])))
+        if not embed_params:
             _logger.warning('for op  %s(%s -> Conv -> %s)', name, inputs,
                             outputs)
             _logger.warning('broken Python code will be generated')
     if embed_params:
-        assert name != ''
         embedded_w = name + '.w_0'
         value_infos[var_w]['embedded_as'].append(embedded_w)
         var_w = embedded_w
@@ -978,11 +992,11 @@ def Conv(prog,
                   param_attr,
                   name_attr,
               ))
-    var_conv = name + '.conv'  # hidden variable
+    var_conv = (name + '.conv') if var_b else var_y  # hidden variable
     prog.OpDesc(
         fluid_op,
-        ([var_x, var_w], 'Input', 'Filter'),  # , 'Bias', 'ResidualData'
-        ([var_conv if var_b else var_y], 'Output'),
+        (['Input', 'Filter'], [var_x, var_w]),  # , 'Bias', 'ResidualData'
+        (['Output'], [var_conv]),
         {
             'strides': strides,
             'paddings': paddings,
@@ -1010,7 +1024,7 @@ def ConvTranspose(prog,
                   outputs,
                   attrs,
                   value_infos,
-                  name='',
+                  name,
                   embed_params=False,
                   *args,
                   **kwargs):
@@ -1019,39 +1033,39 @@ def ConvTranspose(prog,
     """
 
     # I/O
-    var_x, var_w = inputs[:2]
-    var_y, var_b = (outputs + [None] * 1)[:2]
+    var_x, var_w, var_b, = (inputs + [None] * 1)[:3]
+    var_y, = outputs
 
     # interpretation
     assert attrs.get(
-        'auto_pad', 'NOTSET'
-    ) == 'NOTSET', 'only auto_pad == NOTSET is supported'  # optional
-    assert sum(attrs.get(
-        'output_padding',
-        [])) == 0, 'only zero output_padding is supported'  # optional ?
-    kernel_shape = _shape(value_infos, var_w)[2:]  # IO...
-    assert kernel_shape == attrs[
-        'kernel_shape'], 'kernel_shape in attr unmatches value_info'  # HW
+        'auto_pad',
+        'NOTSET') == 'NOTSET', 'only auto_pad = NOTSET supported'  # optional
+    assert sum(
+        attrs.get('output_padding',
+                  [])) == 0, 'only zero output_padding supported'  # optional ?
+    kernel_shape = attrs.get('kernel_shape',
+                             _shape(value_infos, var_w)[2:])  # optional, HW
+    assert kernel_shape, 'kernel_shape not inferred'
     convnd = len(kernel_shape)
-    assert 2 <= convnd <= 3, 'only conv2d_transpose and conv3d_transpose is supported'
+    assert 2 <= convnd <= 3, 'only conv2d_transpose and conv3d_transpose supported'
     num_out_channels = _shape(value_infos, var_w)[1]  # IO...
 
     fluid_op = 'conv{}d_transpose'.format(convnd)
     num_groups = attrs.get('group', 1)  # optional
     strides = attrs.get('strides', [1] * convnd)  # optional
     dilations = attrs.get('dilations', [1] * convnd)  # optional
+    output_size = attrs.get('output_shape', [])  # optional
     pads = attrs.get('pads', [0] * (convnd * 2))  # optional
     paddings, var_x = _pad_if_asymmetric(prog, pads, var_x, value_infos)
-    name_attr = ', name={}'.format(repr(name)) if name else ''
+    name_attr = ', name={}'.format(repr(name))
     if embed_params:
-        embed_params = (_check_embeddable(value_infos, var_w) and not var_b
-                        or _check_embeddable(value_infos, var_b))
-        if not embed_params and name:
+        embed_params = _check_embeddable(
+            value_infos, *([var_w] + ([var_b] if var_b else [])))
+        if not embed_params:
             _logger.warning('for op  %s(%s -> ConvTranspose -> %s)', name,
                             inputs, outputs)
             _logger.warning('broken Python code will be generated')
     if embed_params:
-        assert name != ''
         embedded_w = name + '.w_0'
         value_infos[var_w]['embedded_as'].append(embedded_w)
         var_w = embedded_w
@@ -1070,7 +1084,7 @@ def ConvTranspose(prog,
     # generation
     prog.Code('{} = layers.{}({}'
               ', num_filters={}'
-              #              ', output_size={}'
+              ', output_size={}'
               ', filter_size={}'
               ', padding={}'
               ', stride={}'
@@ -1082,6 +1096,7 @@ def ConvTranspose(prog,
                   var_x,
                   # attrs
                   num_out_channels,
+                  output_size or None,
                   kernel_shape,
                   paddings,
                   strides,
@@ -1090,17 +1105,18 @@ def ConvTranspose(prog,
                   param_attr,
                   name_attr,
               ))
-    var_conv = name + '.conv'  # hidden variable
+    var_conv = (name + '.conv') if var_b else var_y  # hidden variable
     prog.OpDesc(
         fluid_op,
-        ([var_x, var_w], 'Input', 'Filter'),  # , 'Bias', 'ResidualData'
-        ([var_conv if var_b else var_y], 'Output'),
+        (['Input', 'Filter'], [var_x, var_w]),  # , 'Bias', 'ResidualData'
+        (['Output'], [var_conv]),
         {
             'strides': strides,
             'paddings': paddings,
             'dilations': dilations,
-            #					'output_size': output_size,
             'groups': num_groups,
+            # unused
+            'output_size': output_size,
         },
     )
     if var_b:
@@ -1124,7 +1140,7 @@ def Gemm(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
     """
 
     # due to fluid fc don't support transposed weight, we use matmul + ew_add
-    var_a, var_b, var_c = inputs
+    var_a, var_b, var_c, = inputs
     var_y, = outputs
 
     alpha = attrs.get('alpha', 1.)  # optional
@@ -1132,19 +1148,19 @@ def Gemm(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
     trans_a = bool(attrs.get('transA', 0))  # optional
     trans_b = bool(attrs.get('transB', 0))  # optional
 
-    var_mm = name + '_mm'  # explicit variable
+    var_mm = var_y if beta == 0 else (name + '_mmed')  # explicit variable
     prog.Op(
         '',
         'MatMul',
         [var_a, var_b],
-        [var_mm],  # val
+        [var_mm],
         {
             'transpose_x': trans_a,
             'transpose_y': trans_b,
             'alpha': alpha,
         },
         value_infos=value_infos,
-        name=var_mm,
+        name=(name + '_mm'),
     )
     prog.op_descs[-1].attrs.extend(
         prog.OpDescAttrs({
@@ -1157,10 +1173,10 @@ def Gemm(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
                 '',
                 'Add',
                 [var_mm, var_c],
-                [var_y],  # val
+                [var_y],
                 {'axis': 1},
                 value_infos=value_infos,
-                name=(name + '_beta'),
+                name=(name + '_bias'),
             )
         else:
             var_beta = name + '_beta'  # explicit variable
@@ -1179,7 +1195,7 @@ def Gemm(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
                 '',
                 'Constant',
                 [],
-                [var_beta],  # val
+                [var_beta],
                 {'value': beta},
                 value_infos=value_infos,
                 name=var_beta,
@@ -1188,17 +1204,17 @@ def Gemm(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
                 '',
                 'Mul',
                 [var_c, var_beta],
-                [var_vm],  # val
+                [var_vm],
                 dict(),
                 value_infos=value_infos,
-                name=(name + '_scale'),
+                name=(var_beta + '_scale'),
             )
             prog.Op(
                 '',
                 'Add',
                 [var_mm, var_vm],
-                [var_y],  # val
-                {'axis': 1},
+                [var_y],
+                {'axis': 1},  #
                 name=(name + '_bias'),
             )
 
@@ -1250,57 +1266,441 @@ def GRU(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
     onnx::GRU-7:
     """
 
-    var_x, var_w, var_r, var_b, var_len, var_xh = (inputs + [None] * 3)[:6]
-    var_y, var_yh = (outputs + [None] * 2)[:2]
+    var_x, var_w, var_r, var_b, var_len, var_xh, = (inputs + [None] * 3)[:6]
+    var_y, var_yh, = (outputs + [None] * 2)[:2]
+    var_gate = var_y + '.gate'  # dummy output
+    var_reset = var_y + '.reset'  # dummy output
+    var_hidden = var_y + '.hidden'  # dummy output, # var_yh
 
     # interpretation
-    fluid_op = 'gru_unit'
-    param_attr = ''
+    x_shape = _shape_or_none(value_infos, var_x)
+    assert x_shape is not None, 'shape of X required to be known'
+    assert x_shape[1] == 1, 'only X with batch_size = 1 supported'
+    assert 'clip' not in attrs, 'clipping not supported'
+    hidden_size = attrs.get('hidden_size', None)  # optional
+    if not hidden_size:
+        r_shape = _shape_or_none(value_infos, var_r)
+        if r_shape:
+            hidden_size = r_shape[-1]
+    if not hidden_size:
+        w_shape = _shape_or_none(value_infos, var_w)
+        if w_shape:
+            hidden_size = w_shape[-2] // 3
+    if not hidden_size and var_b:
+        b_shape = _shape_or_none(value_infos, var_b)
+        if b_shape:
+            hidden_size = b_shape[-1] // 6
+    if not hidden_size and var_xh:
+        xh_shape = _shape_or_none(value_infos, var_xh)
+        if xh_shape:
+            hidden_size = xh_shape[-1]
+    assert hidden_size, 'hidden_size not inferred'
+    assert attrs.get(
+        'linear_before_reset',
+        0) == 0, 'only linear_before_reset = 0 supported'  # optional
+    direction = attrs.get('direction', 'forward')  # optional
+    assert direction != 'bidirectional', 'direction = bidirectional not supported'
+    activations = attrs.get('activations', ['Sigmoid', 'Tanh'])  # optional
+    assert len(activations) == 2, 'bidirectional operation not supported'
+    activations = [s.lower() for s in activations]  # TODO: check support
+    gate_activation, candidate_activation = activations
+    is_reverse = direction == 'reverse'
+
+    fluid_op = 'dynamic_gru'
 
     # generation
-    prog.Code('{}, _, {} = layers.{}({}, {}, {}'
-              '{})'.format(
-                  var_yh,
-                  var_y,
+    var_x0 = var_x + '_0'  # explicit variable
+    prog.Op(
+        '',
+        'Squeeze',
+        [var_x],
+        [var_x0],
+        {'axes': [1]},  # index on n
+        name=(var_x + '_index'),
+    )
+    var_w0 = var_w + '_0'  # explicit variable
+    prog.Op(
+        '',
+        'Squeeze',
+        [var_w],
+        [var_w0],
+        {'axes': [0]},  # index on d
+        name=(var_w + '_index'),
+    )
+    var_fc = var_x0 + '_fc'
+    var_mm = (var_x0 + '_mmed') if var_b else var_fc
+    prog.Op(
+        '',
+        'MatMul',
+        [var_x0, var_w0],
+        [var_mm],
+        {
+            'transpose_x': 0,
+            'transpose_y': 1,
+        },
+        value_infos=value_infos,
+        name=(var_x0 + '_mm'),
+    )
+    prog.op_descs[-1].attrs.extend(
+        prog.OpDescAttrs({
+            'transpose_X': 0,
+            'transpose_Y': 1,
+        }))  # f**k you API
+    var_r0 = var_r + '_0'  # explicit variable
+    prog.Op(
+        '',
+        'Squeeze',
+        [var_r],
+        [var_r0],
+        {'axes': [0]},  # index on d
+        name=(var_r + '_index'),
+    )
+    var_r0t = var_r0 + '_t'  # explicit variable
+    prog.Op(
+        '',
+        'Transpose',
+        [var_r0],
+        [var_r0t],
+        {'perm': [1, 0]},  # transpose OI->IO
+        name=(var_r0 + '_transpose'),
+    )
+    if var_b:
+        var_bi = var_b + '_i'  # explicit variable
+        var_bh = var_b + '_h'  # explicit variable
+        prog.Op(
+            '',
+            'Split',
+            [var_b],
+            [var_bi, var_bh],
+            {
+                'axis': 1,  # split on x
+                'split': [hidden_size * 3, hidden_size * 3],
+            },
+            name=(var_b + '_split'),
+        )
+        # squeeze bi so Gemm Add can be performed on axis=1 exaclty
+        var_bi0 = var_bi + '_0'  # explicit variable
+        prog.Op(
+            '',
+            'Squeeze',
+            [var_bi],
+            [var_bi0],
+            {'axes': [0]},  # slice on d
+            name=(var_bi + '_index'),
+        )
+        prog.Op(
+            '',
+            'Add',
+            [var_mm, var_bi0],
+            [var_fc],
+            {'axis': 1},  #
+            name=(var_x0 + '_bias'),
+        )
+    if var_xh:
+        var_xh0 = var_xh + '_0'  # explicit variable
+        prog.Op(
+            '',
+            'Squeeze',
+            [var_xh],
+            [var_xh0],
+            {'axes': [1]},  # index on n
+            name=(var_xh + '_index'),
+        )
+    var_y00 = var_y + '_00'  # explicit variable
+    prog.Code('{} = layers.{}({}, {}, origin_mode=True'
+              ', h_0={}'
+              ', is_reverse={}'
+              ', gate_activation={}'
+              ', candidate_activation={}'
+              ', param_attr={}, bias_attr={})'.format(
+                  var_y00,
                   fluid_op,
-                  var_x,
-                  var_xh,
-                  0,
-                  param_attr,
+                  var_fc,
+                  hidden_size,
+                  var_xh0 if var_xh else None,
+                  is_reverse,
+                  repr(gate_activation),
+                  repr(candidate_activation),
+                  repr(var_r0t),
+                  repr(var_bh) if var_b else False,
               ))
 
-
-#    raise NotImplementedError()
+    fluid_op = 'gru'
+    prog.VarDesc(var_y00)
+    prog.VarDesc(var_gate)
+    prog.VarDesc(var_reset)
+    prog.VarDesc(var_hidden)
+    prog.OpDesc(
+        fluid_op,
+        (['Input', 'Weight', 'Bias', 'H0'], [var_fc, var_r0t] +
+         ([var_bh] if var_b else []) + ([var_xh0] if var_xh else [])),
+        (['Hidden', 'BatchGate', 'BatchResetHiddenPrev', 'BatchHidden'
+          ], [var_y00, var_gate, var_reset, var_hidden]),
+        {
+            'is_reverse': is_reverse,
+            'gate_activation': gate_activation,
+            'activation': candidate_activation,
+            'origin_mode': True,
+        },
+    )
+    prog.Op(
+        '',
+        'Unsqueeze',
+        [var_y00],
+        [var_y],
+        {'axes': [1, 1]},  # extrude on dn
+        name=(var_y + '_reshape'),
+    )
 
 
-def LSTM(prog, inputs, outputs, attrs, value_infos, name='', *args, **kwargs):
+def LSTM(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
     """
     onnx::LSTM-7:
     """
 
-    var_x, var_w, var_r, var_b, var_len, var_xh, var_xc, var_p = (
+    var_x, var_w, var_r, var_b, var_len, var_xh, var_xc, var_p, = (
         inputs + [None] * 5)[:8]
-    var_y, var_yh, var_yc = (outputs + [None] * 3)[:3]
+    var_y, var_yh, var_yc, = (outputs + [None] * 3)[:3]
+    var_gate = name + '.gate'
+    var_pre = name + '.pre'
 
     # interpretation
-    fluid_op = 'lstm_unit'
-    param_attr = ''
+    x_shape = _shape_or_none(value_infos, var_x)
+    assert x_shape is not None, 'shape of X required to be known'
+    assert x_shape[1] == 1, 'only X with batch_size = 1 supported'
+    assert 'clip' not in attrs, 'clipping not supported'
+    hidden_size = attrs.get('hidden_size', None)  # optional
+    if not hidden_size:
+        r_shape = _shape_or_none(value_infos, var_r)
+        if r_shape:
+            hidden_size = r_shape[-1]
+    if not hidden_size:
+        w_shape = _shape_or_none(value_infos, var_w)
+        if w_shape:
+            hidden_size = w_shape[-2] // 4
+    if not hidden_size and var_b:
+        b_shape = _shape_or_none(value_infos, var_b)
+        if b_shape:
+            hidden_size = b_shape[-1] // 8
+    if not hidden_size and var_xh:
+        xh_shape = _shape_or_none(value_infos, var_xh)
+        if xh_shape:
+            hidden_size = xh_shape[-1]
+    if not hidden_size and var_xc:
+        xc_shape = _shape_or_none(value_infos, var_xc)
+        if xc_shape:
+            hidden_size = xc_shape[-1]
+    if not hidden_size and var_p:
+        p_shape = _shape_or_none(value_infos, var_p)
+        if p_shape:
+            hidden_size = p_shape[-1] // 3
+    assert hidden_size, 'hidden_size not inferred'
+    assert attrs.get(
+        'linear_before_reset',
+        0) == 0, 'only linear_before_reset = 0 supported'  # optional
+    assert attrs.get('input_forget',
+                     0) == 0, 'only input_forget = 0 supported'  # optional
+    direction = attrs.get('direction', 'forward')  # optional
+    assert direction != 'bidirectional', 'direction = bidirectional not supported'
+    activations = attrs.get('activations',
+                            ['Sigmoid', 'Tanh', 'Tanh'])  # optional
+    assert len(activations) == 3, 'bidirectional operation not supported'
+    activations = [s.lower() for s in activations]  # TODO: check support
+    gate_activation, cell_activation, candidate_activation = activations
+    is_reverse = direction == 'reverse'
+
+    fluid_op = 'dynamic_lstm'
+    name_attr = ', name={}'.format(repr(name))
 
     # generation
-    prog.Code('{}, {}, {} = layers.{}({}, {}, {}'
+    var_x0 = var_x + '_0'  # explicit variable
+    prog.Op(
+        '',
+        'Squeeze',
+        [var_x],
+        [var_x0],
+        {'axes': [1]},  # index on n
+        name=(var_x + '_index'),
+    )
+    var_w0 = var_w + '_0'  # explicit variable
+    prog.Op(
+        '',
+        'Squeeze',
+        [var_w],
+        [var_w0],
+        {'axes': [0]},  # index on d
+        name=(var_w + '_index'),
+    )
+    var_fc = var_x0 + '_fc'
+    var_mm = (var_x0 + '_mmed') if var_b else var_fc
+    prog.Op(
+        '',
+        'MatMul',
+        [var_x0, var_w0],
+        [var_mm],
+        {
+            'transpose_x': 0,
+            'transpose_y': 1,
+        },
+        value_infos=value_infos,
+        name=(name + '_mm'),
+    )
+    prog.op_descs[-1].attrs.extend(
+        prog.OpDescAttrs({
+            'transpose_X': 0,
+            'transpose_Y': 1,
+        }))  # f**k you API
+    var_r0 = var_r + '_0'  # explicit variable
+    prog.Op(
+        '',
+        'Squeeze',
+        [var_r],
+        [var_r0],
+        {'axes': [0]},  # index on d
+        name=(var_r + '_index'),
+    )
+    var_r0t = var_r0 + '_t'  # explicit variable
+    prog.Op(
+        '',
+        'Transpose',
+        [var_r0],
+        [var_r0t],
+        {'perm': [1, 0]},  # transpose OI->IO
+        name=(var_r0 + '_transpose'),
+    )
+    if var_b:
+        var_bi = var_b + '_i'  # explicit variable
+        var_bh = var_b + '_h'  # explicit variable
+        prog.Op(
+            '',
+            'Split',
+            [var_b],
+            [var_bi, var_bh],
+            {
+                'axis': 1,  # split on x
+                'split': [hidden_size * 4, hidden_size * 4],
+            },
+            name=(var_b + '_split'),
+        )
+        # squeeze bi so Gemm Add can be performed on axis=1 exaclty
+        var_bi0 = var_bi + '_0'  # explicit variable
+        prog.Op(
+            '',
+            'Squeeze',
+            [var_bi],
+            [var_bi0],
+            {'axes': [0]},  # slice on d
+            name=(var_bi + '_index'),
+        )
+        prog.Op(
+            '',
+            'Add',
+            [var_mm, var_bi0],
+            [var_fc],
+            {'axis': 1},  #
+            name=(name + '_bias'),
+        )
+    if var_xh:
+        var_xh0 = var_xh + '_0'  # explicit variable
+        prog.Op(
+            '',
+            'Squeeze',
+            [var_xh],
+            [var_xh0],
+            {'axes': [1]},  # index on n
+            name=(var_xh + '_index'),
+        )
+    if var_xc:
+        var_xc0 = var_xc + '_0'  # explicit variable
+        prog.Op(
+            '',
+            'Squeeze',
+            [var_xc],
+            [var_xc0],
+            {'axes': [1]},  # index on n
+            name=(var_xc + '_index'),
+        )
+    var_bhp = var_p
+    if var_b:
+        if var_p:
+            var_bhp = var_bh + '_p'  # explicit variable
+            prog.Op(
+                '',
+                'Concat',
+                [var_bh, var_p],
+                [var_bhp],
+                {'axes': [1]},  # cat on x
+                name=(name + '_concat'),
+            )
+        else:
+            var_bhp = var_bh
+    var_yh0 = var_yh + '_0'  # explicit variable
+    var_yc0 = var_yc + '_0'  # explicit variable
+    prog.Code('{}, {} = layers.{}({}, {}'
+              ', h_0={}'
+              ', c_0={}'
+              ', use_peepholes={}'
+              ', is_reverse={}'
+              ', gate_activation={}'
+              ', cell_activation={}'
+              ', candidate_activation={}'
+              ', param_attr={}, bias_attr={}'
               '{})'.format(
-                  var_y,
-                  var_yh,
-                  var_yc,
+                  var_yh0,
+                  var_yc0,
                   fluid_op,
-                  var_x,
-                  var_xh,
-                  var_xc,
-                  param_attr,
+                  var_fc,
+                  hidden_size * 4,
+                  var_xh0 if var_xh else None,
+                  var_xc0 if var_xc else None,
+                  bool(var_p),
+                  is_reverse,
+                  repr(gate_activation),
+                  repr(cell_activation),
+                  repr(candidate_activation),
+                  repr(var_r0t),
+                  repr(var_bhp) if var_bhp else False,
+                  name_attr,
               ))
 
-
-#    raise NotImplementedError()
+    fluid_op = 'lstm'
+    prog.VarDesc(var_yh0)
+    prog.VarDesc(var_yc0)
+    prog.VarDesc(var_gate)
+    prog.VarDesc(var_pre)
+    prog.OpDesc(
+        fluid_op,
+        (['Input', 'Weight', 'Bias', 'H0', 'C0'], [var_fc, var_r0t] +
+         ([var_bhp] if var_bhp else []) + ([var_xh0] if var_xh else []) +
+         ([var_xc0] if var_xc else [])),
+        (['Hidden', 'Cell', 'BatchGate', 'BatchCellPreAct'
+          ], [var_yh0, var_yc0, var_gate, var_pre]),
+        {
+            'use_peepholes': bool(var_p),
+            'is_reverse': is_reverse,
+            'gate_activation': gate_activation,
+            'cell_activation': cell_activation,
+            'candidate_activation': candidate_activation,
+        },
+    )
+    #    if var_yh:
+    prog.Op(
+        '',
+        'Unsqueeze',
+        [var_yh0],
+        [var_y],  # var_yh
+        {'axes': [1, 1]},  # extrude on dn
+        name=(var_y + '_reshape'),
+    )
+    if var_yc:
+        prog.Op(
+            '',
+            'Unsqueeze',
+            [var_yc0],
+            [var_yc],
+            {'axes': [1, 1]},  # extrude on dn
+            name=(var_yc + '_reshape'),
+        )
 
 
 def MaxPool(prog, inputs, outputs, attrs, value_infos, name='', *args,
@@ -1350,7 +1750,7 @@ def Pad(prog, inputs, outputs, attrs, value_infos, name='', *args, **kwargs):
         od_attrs['mode'] = mode
         od_attrs['data_format'] = "NCHW"
     else:
-        assert mode == 'constant', 'mode {} is supported only in pad2d'.format(
+        assert mode == 'constant', 'mode {} supported only in pad2d'.format(
             mode)
         fluid_op = 'pad'
         pad2d_attr = ''
@@ -1376,8 +1776,8 @@ def Pad(prog, inputs, outputs, attrs, value_infos, name='', *args, **kwargs):
     prog.VarDesc(var_output)
     prog.OpDesc(
         fluid_op,
-        ([var_data], 'X'),
-        ([var_output], 'Out'),
+        (['X'], [var_data]),
+        (['Out'], [var_output]),
         od_attrs,
     )
 
@@ -1396,7 +1796,7 @@ def PRelu(prog,
     """
 
     # I/O
-    var_x, var_slope = inputs
+    var_x, var_slope, = inputs
     var_y, = outputs
 
     # interpretation
@@ -1441,8 +1841,8 @@ def PRelu(prog,
     prog.VarDesc(var_y)
     prog.OpDesc(
         fluid_op,
-        ([var_x, var_slope], 'X', 'Alpha'),
-        ([var_y], 'Out'),
+        (['X', 'Alpha'], [var_x, var_slope]),
+        (['Out'], [var_y]),
         {'mode': mode},
     )
 
@@ -1461,7 +1861,7 @@ def Reshape(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
     """
 
     # I/O
-    var_data, var_shape = inputs
+    var_data, var_shape, = inputs
     var_reshaped, = outputs
 
     # interpretation
@@ -1481,7 +1881,7 @@ def Reshape(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
             'the behavior of Paddle fluid maybe undefined', name, inputs,
             outputs)
     fluid_op = 'reshape'
-    name_attr = ', name={}'.format(repr(name)) if name else ''
+    name_attr = ', name={}'.format(repr(name))
 
     # generation
     var_shape_int32 = var_shape + '_int32'  # explicit variable
@@ -1502,7 +1902,7 @@ def Reshape(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
             '',
             'Cast',
             [var_shape],
-            [var_shape_int32],  # var
+            [var_shape_int32],
             {'to': _np.dtype('int32')},  # use np.dtype
             value_infos=value_infos,
             name=(name + '_cast'),
@@ -1525,8 +1925,8 @@ def Reshape(prog, inputs, outputs, attrs, value_infos, name, *args, **kwargs):
     prog.VarDesc(var_xshape)
     prog.OpDesc(
         fluid_op,
-        ([var_data, var_shape_int32], 'X', 'Shape'),
-        ([var_reshaped, var_xshape], 'Out', 'XShape'),
+        (['X', 'Shape'], [var_data, var_shape_int32]),
+        (['Out', 'XShape'], [var_reshaped, var_xshape]),
         {'shape': shape},
     )
 
@@ -1626,8 +2026,8 @@ def Slice(prog, inputs, outputs, attrs, value_infos, *args, **kwargs):
     prog.VarDesc(var_output)
     prog.OpDesc(
         fluid_op,
-        ([var_data], 'Input'),
-        ([var_output], 'Out'),
+        (['Input'], [var_data]),
+        (['Out'], [var_output]),
         {
             'axes': axes,
             'starts': starts,
@@ -1666,11 +2066,13 @@ def Split(prog, inputs, outputs, attrs, *args, name='', **kwargs):
         prog.VarDesc(var_out)
     prog.OpDesc(
         fluid_op,
-        (var_input, 'X'),
-        ([outputs], *(['Out'] * len(outputs))),
+        (['X'], [var_input]),
+        (['Out'] * len(outputs), outputs),
         {
             'axis': axis,
             'sections': split,
+            # unused
+            'num': 0,
         },
     )
 
@@ -1697,8 +2099,8 @@ def Sum(prog, inputs, outputs, *args, **kwargs):
     prog.VarDesc(var_sum)
     prog.OpDesc(
         fluid_op,
-        (inputs, *(['X'] * len(inputs))),
-        ([var_sum], 'Out'),
+        (['X'] * len(inputs), inputs),
+        (['Out'], [var_sum]),
         dict(),
     )
 
@@ -1709,12 +2111,12 @@ def Tile(prog, inputs, outputs, attrs, value_infos, name='', *args, **kwargs):
     """
 
     # I/O
-    var_input, var_repeats = inputs
+    var_input, var_repeats, = inputs
     var_output, = outputs
 
     # interpretation
     repeats = _const_weight_or_none(value_infos, var_repeats)
-    assert repeats is not None, 'only const repeats is supported'
+    assert repeats is not None, 'only const repeats supported'
     fluid_op = 'expand'
     name_attr = ', name={}'.format(repr(name)) if name else ''
 
@@ -1733,8 +2135,8 @@ def Tile(prog, inputs, outputs, attrs, value_infos, name='', *args, **kwargs):
     prog.VarDesc(var_output)
     prog.OpDesc(
         fluid_op,
-        ([var_input], 'X'),
-        ([var_output], 'Out'),
+        (['X'], [var_input]),
+        (['Out'], [var_output]),
         {'expand_times': repeats},
     )
 
@@ -1770,8 +2172,8 @@ def Transpose(prog, inputs, outputs, attrs, *args, name='', **kwargs):
     prog.VarDesc(var_transposed)
     prog.OpDesc(
         fluid_op,
-        ([var_data], 'X'),
-        ([var_transposed, var_xshape], 'Out', 'XShape'),
+        (['X'], [var_data]),
+        (['Out', 'XShape'], [var_transposed, var_xshape]),
         {'axis': perm},  # f**k you API
     )
 
diff --git a/onnx2fluid/onnx2fluid/validation.py b/onnx2fluid/onnx2fluid/validation.py
index 4374c7eb448fddafbf1514657545c30acefbeaa5..b397725d017db5c5c720621d53516fcc99aba5c7 100644
--- a/onnx2fluid/onnx2fluid/validation.py
+++ b/onnx2fluid/onnx2fluid/validation.py
@@ -159,7 +159,7 @@ def validate(fluid_model_filename,
         #        output_names = output_data.keys()
         logger.info('with %d inputs and %d outputs', len(input_data),
                     len(output_data))
-    else:
+    elif save_inference_model:
         assert inference_input_names, 'input names required for type-shape inference'
 
         input_names = inference_input_names
diff --git a/onnx2fluid/onnx2fluid/writer.py b/onnx2fluid/onnx2fluid/writer.py
index 9d8ba4b7990b2bf0e9357afd3a1583943ed64e6b..90ac8a9ca8bbc43ce390ffeaadc8fb451cb11a09 100644
--- a/onnx2fluid/onnx2fluid/writer.py
+++ b/onnx2fluid/onnx2fluid/writer.py
@@ -96,7 +96,7 @@ class Program(object):
         return Program.DTYPE_TO_FRAMEWORK_DTYPE[dtype]
 
     @staticmethod
-    def OpDescVars(vals, *keys):
+    def OpDescVars(keys, vals):
         """
         make (OpDesc.Var)s
         """
@@ -150,13 +150,11 @@ class Program(object):
                     else:
                         raise ValueError('unsupported attribute {} = {}'.format(
                             key, value))
-                else:  # WORKAROUND: shape of scalars is []
-                    raise ValueError('unsupported attribute {} = {}'.format(
-                        key, value))
-
-
-#                    od_attr.type = framework_pb2.INTS
-#                    logger.warning('using attribute %s = %s as INTS', key, value)
+                else:  # WORKAROUND: [] not inferred
+                    #                    raise ValueError('unsupported attribute {} = {}'.format(key, value))
+                    od_attr.type = framework_pb2.INTS
+                    logger.warning('using attribute %s = %s as INTS', key,
+                                   value)
             else:
                 raise ValueError('unsupported attribute {} = {}'.format(
                     key, value))
@@ -187,8 +185,8 @@ class Program(object):
 
     def OpDesc(self,
                op_type,
-               input_val_keys=None,
-               output_val_keys=None,
+               input_key_vals=None,
+               output_key_vals=None,
                attrs=None):
         """
         add OpDesc
@@ -196,10 +194,10 @@ class Program(object):
 
         desc = framework_pb2.OpDesc()
         desc.type = op_type
-        if input_val_keys:
-            desc.inputs.extend(self.OpDescVars(*input_val_keys))
-        if output_val_keys:
-            desc.outputs.extend(self.OpDescVars(*output_val_keys))
+        if input_key_vals:
+            desc.inputs.extend(self.OpDescVars(*input_key_vals))
+        if output_key_vals:
+            desc.outputs.extend(self.OpDescVars(*output_key_vals))
         if attrs:
             desc.attrs.extend(self.OpDescAttrs(attrs))
         self.op_descs.append(desc)
@@ -388,8 +386,8 @@ class Writer(object):
             ))
             prog.OpDesc(
                 'feed',
-                (['feed'], 'X'),
-                ([name], 'Out'),
+                (['X'], ['feed']),
+                (['Out'], [name]),
                 {'col': idx},
             )
             prog.VarDesc(name, value_info=value_info, remove_batch=remove_batch)
@@ -406,8 +404,8 @@ class Writer(object):
 
             prog.OpDesc(
                 'fetch',
-                ([name], 'X'),
-                (['fetch'], 'Out'),
+                (['X'], [name]),
+                (['Out'], ['fetch']),
                 {'col': idx},
             )
             # var is emitted over ops
@@ -424,12 +422,16 @@ class Writer(object):
         return codes
 
     @staticmethod
-    def write_weight(weight, filename):
+    def write_weight(weight, filename, lod=None):
         """
         write single weight in fluid desc
         """
 
         assert isinstance(weight, np.ndarray), 'weight is not an ndarray'
+        assert lod is None or isinstance(lod,
+                                         list), 'lod should be None or list'
+
+        lod = lod or [0]
 
         tensor_desc = framework_pb2.VarType.TensorDesc()
         tensor_desc.data_type = Program.Dtype(weight.dtype)
@@ -437,7 +439,7 @@ class Writer(object):
 
         fp = open(filename, 'wb')
         np.array([0], dtype=np.int32).tofile(fp)  # version
-        np.array([0], dtype=np.int64).tofile(fp)  # LOD level
+        np.array(lod, dtype=np.int64).tofile(fp)  # LOD level
         np.array([0], dtype=np.int32).tofile(fp)  # tensor version
         np.array([tensor_desc.ByteSize()], dtype=np.int32).tofile(fp)
         fp.write(tensor_desc.SerializeToString())