mirror of https://github.com/alibaba/MNN.git
70 lines
3.0 KiB
Python
70 lines
3.0 KiB
Python
import os
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import onnx
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class OnnxRebuilder:
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def __init__(self, onnx_path, weight_ops):
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self.weight_ops = weight_ops
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self.onnx_model = onnx.load(onnx_path)
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self.dst_path = onnx_path
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self.onnx_weight_path = f'{onnx_path}.data'
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self.onnx_weight_offset = 0
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def make_external(self, name, data, shape):
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# write to external weight
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length = self.onnx_weight.write(data.tobytes())
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location = os.path.basename(self.onnx_weight_path)
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offset = self.onnx_weight_offset
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self.onnx_weight_offset += length
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tensor = onnx.TensorProto()
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tensor.name = name
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tensor.data_type = onnx.TensorProto.FLOAT
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tensor.dims.extend(shape)
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# external info
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tensor.data_location = onnx.TensorProto.EXTERNAL
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for k, v in { "location": location, "offset": offset, "length": length }.items():
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entry = tensor.external_data.add()
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entry.key = k
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entry.value = str(v)
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self.onnx_model.graph.initializer.append(tensor)
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def build_weight(self, name, has_bias, ic, oc):
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assert(name in self.weight_ops)
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linear = self.weight_ops[name]
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assert(linear.in_features == ic and
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linear.out_features == oc and
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(linear.bias is not None) == has_bias)
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weight_name, bias_name = f'{name}_weight', f'{name}_bias'
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weight = linear.weight.data.transpose(1, 0).flatten().float().numpy()
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self.make_external(weight_name, weight, [ic, oc])
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if has_bias:
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bias = linear.bias.data.flatten().float().numpy()
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self.make_external(bias_name, bias, [oc])
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return weight_name, bias_name
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def rebuild(self):
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from onnx import helper
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new_nodes = []
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self.onnx_weight = open(self.onnx_weight_path, 'wb')
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for node in self.onnx_model.graph.node:
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if node.op_type == 'FakeLinear':
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attributes = {a.name: a for a in node.attribute}
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name = attributes.get('name').s.decode('utf-8')
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has_bias = attributes.get('has_bias').i
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ic = attributes.get('in_features').i
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oc = attributes.get('out_features').i
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weight, bias = self.build_weight(name, has_bias, ic, oc)
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if has_bias:
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# fakelinear -> matmul + add
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middle_tensor = f'{name}_matmul'
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new_nodes.append(helper.make_node('MatMul', [node.input[0], weight], [middle_tensor], name))
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new_nodes.append(helper.make_node('Add', [middle_tensor, bias], node.output, f'{name}/Add'))
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else:
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# fakelinear -> matmul
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new_nodes.append(helper.make_node('MatMul', [node.input[0], weight], node.output, name))
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else:
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new_nodes.append(node)
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self.onnx_weight.close()
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del self.onnx_model.graph.node[:]
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self.onnx_model.graph.node.extend(new_nodes)
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onnx.save(self.onnx_model, self.dst_path)
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return self.onnx_weight_path |