Change the float-type const tensor to half type.

python/tools/model.template

@@ -17,7 +17,7 @@ namespace {{tag}} {
 void Create{{tensor.name}}(std::vector<mace::ConstTensor> &tensors) {
   tensors.emplace_back(mace::ConstTensor(
       {{ tensor.name|tojson }}, {{ tensor.name }},
-      { {{ tensor.dims|join(', ') }} }, {{ tensor.data_type }}, {{ tensor.node_id }}));
+      { {{ tensor.dims|join(', ') }} }, {{ tensor_info.data_type }}, {{ tensor.node_id }}));
 }
 
 }  // namespace {{tag}}

python/tools/source_converter_lib.py

@@ -77,9 +77,10 @@ class TensorInfo:
     self.name = t.name
     self.data_type = mace_pb2.DataType.Name(t.data_type)
     if t.data_type == mace_pb2.DT_FLOAT:
-      self.data = bytearray(struct.pack('%sf' % len(t.float_data), *t.float_data))
+      self.data_type = mace_pb2.DT_HALF
+      self.data = bytearray(np.array(t.float_data).astype(np.float16).tobytes())
     elif t.data_type == mace_pb2.DT_INT32:
-      self.data = bytearray(struct.pack('%si' % len(t.int32_data), *t.int32_data))
+      self.data = bytearray(np.array(t.int32_data).astype(np.int32).tobytes())
     elif t.data_type == mace_pb2.DT_UINT8:
       self.data = bytearray(np.array(t.int32_data).astype(np.uint8).tolist())