add new API: paddle.clone;Tensor.element_size;nn.utils.parameters_to_vector (#38020)

* add new API: paddle.clone;Tensor.element_size;nn.utils.parameters_to_vector

* fix comment

CMakeLists.txt

@@ -126,6 +126,8 @@ if(WIN32)
         endforeach(flag_var)
     endif()
 
+    # NOTE(zhouwei): msvc max/min macro conflict with std::min/max, define NOMINMAX globally
+    add_definitions("-DNOMINMAX")
     # windows build turn off warnings, use parallel compiling.
     foreach(flag_var
         CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE

paddle/fluid/framework/var_desc.cc

@@ -15,6 +15,7 @@ limitations under the License. */
 #include "paddle/fluid/framework/var_desc.h"
 
 #include "glog/logging.h"
+#include "paddle/fluid/framework/data_type.h"
 #include "paddle/fluid/platform/enforce.h"
 
 namespace paddle {
@@ -116,6 +117,10 @@ proto::VarType::Type VarDesc::GetDataType() const {
   return tensor_desc().data_type();
 }
 
+size_t VarDesc::ElementSize() const {
+  return framework::SizeOfType(GetDataType());
+}
+
 std::vector<proto::VarType::Type> VarDesc::GetDataTypes() const {
   std::vector<proto::VarType::TensorDesc> descs = tensor_descs();
   std::vector<proto::VarType::Type> res;

paddle/fluid/framework/var_desc.h

@@ -96,6 +96,8 @@ class VarDesc {
 
   proto::VarType::Type GetDataType() const;
 
+  size_t ElementSize() const;
+
   std::vector<proto::VarType::Type> GetDataTypes() const;
 
   void SetLoDLevel(int32_t lod_level);

paddle/fluid/imperative/layer.h

@@ -25,6 +25,7 @@
 #include <utility>
 #include <vector>
 
+#include "paddle/fluid/framework/data_type.h"
 #include "paddle/fluid/framework/operator.h"
 #include "paddle/fluid/framework/type_defs.h"
 #include "paddle/fluid/framework/var_type.h"
@@ -37,7 +38,6 @@
 #include "paddle/fluid/platform/enforce.h"
 #include "paddle/fluid/platform/macros.h"
 #include "paddle/pten/include/core.h"
-
 namespace paddle {
 namespace framework {
 class Variable;
@@ -212,6 +212,8 @@ class VarBase {
 
   framework::proto::VarType::Type DataType() const { return var_->DataType(); }
 
+  size_t ElementSize() const { return framework::SizeOfType(var_->DataType()); }
+
   void SetForwardDataType(framework::proto::VarType::Type data_type) {
     var_->SetForwardDataType(data_type);
   }

paddle/fluid/pybind/imperative.cc

@@ -2013,6 +2013,29 @@ void BindImperative(py::module *m_ptr) {
              auto *t = self->MutableVar()->GetMutable<framework::LoDTensor>();
              return t->numel();
            })
+      .def("element_size", &imperative::VarBase::ElementSize, R"DOC(
+        Returns the size in bytes of an element in the Tensor.
+        
+        Examples:
+          .. code-block:: python
+
+            import paddle
+
+            x = paddle.to_tensor(1, dtype='bool')
+            x.element_size() # 1
+
+            x = paddle.to_tensor(1, dtype='float16')
+            x.element_size() # 2
+
+            x = paddle.to_tensor(1, dtype='float32')
+            x.element_size() # 4
+
+            x = paddle.to_tensor(1, dtype='float64')
+            x.element_size() # 8
+
+            x = paddle.to_tensor(1, dtype='complex128')
+            x.element_size() # 16
+       )DOC")
       .def_property("name", &imperative::VarBase::Name,
                     &imperative::VarBase::SetName)
       .def_property("stop_gradient",
@@ -2020,21 +2043,33 @@ void BindImperative(py::module *m_ptr) {
                     &imperative::VarBase::SetOverridedStopGradient)
       .def_property("persistable", &imperative::VarBase::Persistable,
                     &imperative::VarBase::SetPersistable)
-      .def_property_readonly(
-          "shape",
+      .def_property_readonly("shape",
                              [](imperative::VarBase &self) {
                                if (self.Var().IsType<framework::LoDTensor>()) {
                                  return framework::vectorize<int>(
-                  self.Var().Get<framework::LoDTensor>().dims());
-            } else if (self.Var().IsType<framework::SelectedRows>()) {
+                                     self.Var()
+                                         .Get<framework::LoDTensor>()
+                                         .dims());
+                               } else if (self.Var()
+                                              .IsType<
+                                                  framework::SelectedRows>()) {
                                  return framework::vectorize<int>(
-                  self.Var().Get<framework::SelectedRows>().value().dims());
-            } else if (self.Var().IsType<framework::Strings>()) {
+                                     self.Var()
+                                         .Get<framework::SelectedRows>()
+                                         .value()
+                                         .dims());
+                               } else if (self.Var()
+                                              .IsType<framework::Strings>()) {
+                                 return std::vector<int>{static_cast<int>(
+                                     self.Var()
+                                         .Get<framework::Strings>()
+                                         .size())};
+                               } else if (self.Var()
+                                              .IsType<framework::Vocab>()) {
                                  return std::vector<int>{static_cast<int>(
-                  self.Var().Get<framework::Strings>().size())};
-            } else if (self.Var().IsType<framework::Vocab>()) {
-              return std::vector<int>{
-                  static_cast<int>(self.Var().Get<framework::Vocab>().size())};
+                                     self.Var()
+                                         .Get<framework::Vocab>()
+                                         .size())};
                                } else {
                                  VLOG(2) << "It is meaningless to get shape of "
                                             "variable type "

paddle/fluid/pybind/protobuf.cc

@@ -179,6 +179,8 @@ void BindVarDsec(pybind11::module *m) {
            pybind11::return_value_policy::reference)
       .def("dtype", &pd::VarDesc::GetDataType,
            pybind11::return_value_policy::reference)
+      .def("element_size", &pd::VarDesc::ElementSize,
+           pybind11::return_value_policy::reference)
       .def("dtypes", &pd::VarDesc::GetDataTypes,
            pybind11::return_value_policy::reference)
       .def("lod_level", &pd::VarDesc::GetLoDLevel)

python/paddle/__init__.py

@@ -91,6 +91,7 @@ from .tensor.creation import empty  # noqa: F401
 from .tensor.creation import empty_like  # noqa: F401
 from .tensor.creation import assign  # noqa: F401
 from .tensor.creation import complex  # noqa: F401
+from .tensor.creation import clone  # noqa: F401
 from .tensor.linalg import matmul  # noqa: F401
 from .tensor.linalg import dot  # noqa: F401
 from .tensor.linalg import norm  # noqa: F401
@@ -587,4 +588,5 @@ __all__ = [  # noqa
            'fmin',
            'moveaxis',
            'repeat_interleave',
+           'clone',
 ]

python/paddle/fluid/framework.py

@@ -1396,6 +1396,33 @@ class Variable(object):
 
     __repr__ = __str__
 
+    def element_size(self):
+        """
+        Returns the size in bytes of an element in the Tensor.
+        
+        Examples:
+          .. code-block:: python
+
+            import paddle
+            paddle.enable_static()
+
+            x = paddle.static.data(name='x1', shape=[3, 2], dtype='bool')
+            x.element_size() # 1
+
+            x = paddle.static.data(name='x2', shape=[3, 2], dtype='int16')
+            x.element_size() # 2
+
+            x = paddle.static.data(name='x3', shape=[3, 2], dtype='float16')
+            x.element_size() # 2
+
+            x = paddle.static.data(name='x4', shape=[3, 2], dtype='float32')
+            x.element_size() # 4
+
+            x = paddle.static.data(name='x5', shape=[3, 2], dtype='float64')
+            x.element_size() # 8
+        """
+        return self.desc.element_size()
+
     @property
     def stop_gradient(self):
         """

python/paddle/fluid/tests/unittests/test_assign_op.py

@@ -169,6 +169,31 @@ class TestAssignOApi(unittest.TestCase):
         self.assertTrue(np.allclose(result3.numpy(), np.array([1])))
         paddle.enable_static()
 
+    def test_clone(self):
+        paddle.disable_static()
+        x = paddle.ones([2])
+        x.stop_gradient = False
+        clone_x = paddle.clone(x)
+
+        y = clone_x**3
+        y.backward()
+
+        self.assertTrue(np.array_equal(x, [1, 1]), True)
+        self.assertTrue(np.array_equal(clone_x.grad.numpy(), [3, 3]), True)
+        self.assertTrue(np.array_equal(x.grad.numpy(), [3, 3]), True)
+        paddle.enable_static()
+
+        with program_guard(Program(), Program()):
+            x_np = np.random.randn(2, 3).astype('float32')
+            x = paddle.static.data("X", shape=[2, 3])
+            clone_x = paddle.clone(x)
+            exe = paddle.static.Executor()
+            y_np = exe.run(paddle.static.default_main_program(),
+                           feed={'X': x_np},
+                           fetch_list=[clone_x])[0]
+
+        self.assertTrue(np.array_equal(y_np, x_np), True)
+
 
 class TestAssignOpErrorApi(unittest.TestCase):
     def test_errors(self):

python/paddle/fluid/tests/unittests/test_parameter.py

@@ -18,18 +18,19 @@ import unittest
 import copy
 import paddle
 from paddle.fluid.dygraph import guard
-from paddle.fluid.framework import default_main_program
+from paddle.fluid.framework import default_main_program, Variable
 import paddle.fluid.core as core
 from paddle.fluid.executor import Executor
 import paddle.fluid.io as io
 from paddle.fluid.initializer import ConstantInitializer
 import numpy as np
 
+paddle.enable_static()
 main_program = default_main_program()
 
 
 class ParameterChecks(unittest.TestCase):
-    def check_parameter(self):
+    def test_parameter(self):
         shape = [784, 100]
         val = 1.0625
         b = main_program.global_block()
@@ -43,13 +44,13 @@ class ParameterChecks(unittest.TestCase):
         self.assertEqual((784, 100), param.shape)
         self.assertEqual(core.VarDesc.VarType.FP32, param.dtype)
         self.assertEqual(0, param.block.idx)
-        exe = Executor(core.CPUPlace())
+        exe = Executor(paddle.CPUPlace())
         p = exe.run(main_program, fetch_list=[param])[0]
-        self.assertTrue(np.allclose(p, np.ones(shape) * val))
+        self.assertTrue(np.array_equal(p, np.ones(shape) * val))
         p = io.get_parameter_value_by_name('fc.w', exe, main_program)
-        self.assertTrue(np.allclose(np.array(p), np.ones(shape) * val))
+        self.assertTrue(np.array_equal(p, np.ones(shape) * val))
 
-    def check_parambase(self):
+    def test_parambase(self):
         with guard():
             linear = paddle.nn.Linear(10, 10)
             param = linear.weight
@@ -71,7 +72,7 @@ class ParameterChecks(unittest.TestCase):
             pram_copy2 = copy.deepcopy(param, memo)
             self.assertEqual(id(param_copy), id(pram_copy2))
 
-    def check_exceptions(self):
+    def test_exception(self):
         b = main_program.global_block()
         with self.assertRaises(ValueError):
             b.create_parameter(
@@ -86,16 +87,30 @@ class ParameterChecks(unittest.TestCase):
             b.create_parameter(
                 name='test', shape=[-1], dtype='float32', initializer=None)
 
+    def test_parambase_to_vector(self):
+        with guard():
+            initializer = paddle.ParamAttr(
+                initializer=paddle.nn.initializer.Constant(3.))
+            linear1 = paddle.nn.Linear(10, 15, initializer)
 
-class TestParameter(ParameterChecks):
-    def _test_parameter(self):
-        self.check_parameter()
-
-    def test_parambase(self):
-        self.check_parambase()
+            vec = paddle.nn.utils.parameters_to_vector(linear1.parameters())
+            self.assertEqual(linear1.weight.shape, [10, 15])
+            self.assertEqual(linear1.bias.shape, [15])
+            self.assertTrue(isinstance(vec, Variable))
+            self.assertTrue(vec.shape, [165])
 
-    def test_exceptions(self):
-        self.check_exceptions()
+            linear2 = paddle.nn.Linear(10, 15)
+            paddle.nn.utils.vector_to_parameters(vec, linear2.parameters())
+            self.assertEqual(linear2.weight.shape, [10, 15])
+            self.assertEqual(linear2.bias.shape, [15])
+            self.assertTrue(
+                np.array_equal(linear1.weight.numpy(), linear2.weight.numpy()),
+                True)
+            self.assertTrue(
+                np.array_equal(linear1.bias.numpy(), linear2.bias.numpy()),
+                True)
+            self.assertTrue(linear2.weight.is_leaf, True)
+            self.assertTrue(linear2.bias.is_leaf, True)
 
 
 if __name__ == '__main__':

python/paddle/fluid/tests/unittests/test_var_base.py

@@ -497,6 +497,41 @@ class TestVarBase(unittest.TestCase):
             var = fluid.dygraph.to_variable(self.array)
             self.assertTrue(isinstance(str(var), str))
 
+    def test_element_size(self):
+        with fluid.dygraph.guard():
+            x = paddle.to_tensor(1, dtype='bool')
+            self.assertEqual(x.element_size(), 1)
+
+            x = paddle.to_tensor(1, dtype='float16')
+            self.assertEqual(x.element_size(), 2)
+
+            x = paddle.to_tensor(1, dtype='float32')
+            self.assertEqual(x.element_size(), 4)
+
+            x = paddle.to_tensor(1, dtype='float64')
+            self.assertEqual(x.element_size(), 8)
+
+            x = paddle.to_tensor(1, dtype='int8')
+            self.assertEqual(x.element_size(), 1)
+
+            x = paddle.to_tensor(1, dtype='int16')
+            self.assertEqual(x.element_size(), 2)
+
+            x = paddle.to_tensor(1, dtype='int32')
+            self.assertEqual(x.element_size(), 4)
+
+            x = paddle.to_tensor(1, dtype='int64')
+            self.assertEqual(x.element_size(), 8)
+
+            x = paddle.to_tensor(1, dtype='uint8')
+            self.assertEqual(x.element_size(), 1)
+
+            x = paddle.to_tensor(1, dtype='complex64')
+            self.assertEqual(x.element_size(), 8)
+
+            x = paddle.to_tensor(1, dtype='complex128')
+            self.assertEqual(x.element_size(), 16)
+
     def test_backward(self):
         with fluid.dygraph.guard():
             var = fluid.dygraph.to_variable(self.array)

python/paddle/fluid/tests/unittests/test_variable.py

@@ -63,6 +63,35 @@ class TestVariable(unittest.TestCase):
         self.assertRaises(ValueError,
                           lambda: b.create_var(name="fc.w", shape=(24, 100)))
 
+    def test_element_size(self):
+        with fluid.program_guard(Program(), Program()):
+            x = paddle.static.data(name='x1', shape=[2], dtype='bool')
+            self.assertEqual(x.element_size(), 1)
+
+            x = paddle.static.data(name='x2', shape=[2], dtype='float16')
+            self.assertEqual(x.element_size(), 2)
+
+            x = paddle.static.data(name='x3', shape=[2], dtype='float32')
+            self.assertEqual(x.element_size(), 4)
+
+            x = paddle.static.data(name='x4', shape=[2], dtype='float64')
+            self.assertEqual(x.element_size(), 8)
+
+            x = paddle.static.data(name='x5', shape=[2], dtype='int8')
+            self.assertEqual(x.element_size(), 1)
+
+            x = paddle.static.data(name='x6', shape=[2], dtype='int16')
+            self.assertEqual(x.element_size(), 2)
+
+            x = paddle.static.data(name='x7', shape=[2], dtype='int32')
+            self.assertEqual(x.element_size(), 4)
+
+            x = paddle.static.data(name='x8', shape=[2], dtype='int64')
+            self.assertEqual(x.element_size(), 8)
+
+            x = paddle.static.data(name='x9', shape=[2], dtype='uint8')
+            self.assertEqual(x.element_size(), 1)
+
     def test_step_scopes(self):
         prog = Program()
         b = prog.current_block()

python/paddle/nn/utils/__init__.py

@@ -14,7 +14,8 @@
 
 from .spectral_norm_hook import spectral_norm
 from .weight_norm_hook import weight_norm, remove_weight_norm  # noqa: F401
+from .transform_parameters import parameters_to_vector, vector_to_parameters  # noqa: F401
 
 __all__ = [  #noqa
-    'weight_norm', 'remove_weight_norm', 'spectral_norm'
+    'weight_norm', 'remove_weight_norm', 'spectral_norm', 'parameters_to_vector', 'vector_to_parameters'
 ]

python/paddle/nn/utils/transform_parameters.py

+# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from functools import reduce
+
+import paddle
+from paddle.fluid.framework import dygraph_only, _dygraph_tracer, _varbase_creator
+from paddle import _C_ops
+
+
+#input==output, inplace strategy of reshape has no cost almostly
+def _inplace_reshape_dygraph(x, shape):
+    x_shape = _varbase_creator(dtype=x.dtype)
+    _dygraph_tracer().trace_op(
+        type="reshape2",
+        inputs={'X': x},
+        outputs={'Out': x,
+                 'XShape': x_shape},
+        attrs={'shape': shape},
+        stop_gradient=True)
+
+
+@dygraph_only
+def parameters_to_vector(parameters, name=None):
+    """
+    Flatten parameters to a 1-D Tensor.
+
+    Args:
+        parameters(Iterable[Tensor]): Iterable Tensors that are trainable parameters of a Layer.
+        name(str, optional): The default value is None. Normally there is no need for user to set this
+            property. For more information, please refer to :ref:`api_guide_Name`.
+
+    Returns:
+        A 1-D Tensor, which represents the parameters of a Layer.
+    
+
+    Examples:
+       .. code-block:: python
+
+            import paddle
+            linear = paddle.nn.Linear(10, 15)
+
+            paddle.nn.utils.parameters_to_vector(linear.parameters())
+            # 1-D Tensor: [165]
+
+    """
+    dtype = parameters[0].dtype
+    origin_shapes = []
+    for param in parameters:
+        origin_shapes.append(param.shape)
+        _inplace_reshape_dygraph(param, [-1])
+
+    out = _varbase_creator(dtype=dtype)
+    _dygraph_tracer().trace_op(
+        type='concat',
+        inputs={'X': parameters},
+        outputs={'Out': [out]},
+        attrs={'axis': 0},
+        stop_gradient=True)
+    for i, param in enumerate(parameters):
+        _inplace_reshape_dygraph(param, origin_shapes[i])
+    return out
+
+
+@dygraph_only
+def vector_to_parameters(vec, parameters, name=None):
+    """
+    Transform a Tensor with 1-D shape to the parameters.
+
+    Args:
+        vec (Tensor): A Tensor with 1-D shape, which represents the parameters of a Layer.
+        parameters (Iterable[Tensor]): Iterable Tensors that are trainable parameters of a Layer.
+        name(str, optional): The default value is None. Normally there is no need for user to set this
+            property. For more information, please refer to :ref:`api_guide_Name`.
+
+    Examples:
+       .. code-block:: python
+
+            import paddle
+            weight_attr = paddle.ParamAttr(initializer=paddle.nn.initializer.Constant(3.))
+            linear1 = paddle.nn.Linear(10, 15, weight_attr)
+
+            vec = paddle.nn.utils.parameters_to_vector(linear1.parameters())
+
+            linear2 = paddle.nn.Linear(10, 15)
+            # copy weight of linear1 to linear2
+            paddle.nn.utils.vector_to_parameters(vec, linear2.parameters())
+            # weight: Tensor(shape=[10, 15], dtype=float32, place=CUDAPlace(0), stop_gradient=False,
+            #                 [[3. , ..., 3. ],
+            #                  [..., ..., ...],
+            #                  [3. , ..., 3. ]])
+    """
+    origin_shapes = []
+    sections = []
+    for param in parameters:
+        shape = param.shape
+        origin_shapes.append(shape)
+        numel = reduce(lambda x, y: x * y, shape)
+        sections.append(numel)
+
+    _dygraph_tracer().trace_op(
+        type='split',
+        inputs={'X': [vec]},
+        outputs={'Out': parameters},
+        attrs={'axis': 0,
+               'sections': sections},
+        stop_gradient=True)
+
+    for i, param in enumerate(parameters):
+        _inplace_reshape_dygraph(param, origin_shapes[i])
+    return

python/paddle/tensor/creation.py

@@ -1159,7 +1159,6 @@ def empty_like(x, dtype=None, name=None):
 def assign(x, output=None):
     """
 
- 
     The OP copies the :attr:`x` to the :attr:`output`.
  
     Parameters:
@@ -1192,6 +1191,36 @@ def assign(x, output=None):
     return tensor.assign(x, output)
 
 
+def clone(x, name=None):
+    """
+    Returns a copy of input Tensor. It will always have a Tensor copy. 
+    
+    In addition, This function is derivable, so gradients will flow back from the output to input.
+
+    Parameters:
+        x (Tensor): The input Tensor.
+        name(str, optional): The default value is None. Normally there is no need for user to set this
+            property. For more information, please refer to :ref:`api_guide_Name`.
+
+    Returns: A Tensor copied from ``input`` .
+
+    Examples:
+        .. code-block:: python
+
+            import paddle
+
+            x = paddle.ones([2])
+            x.stop_gradient = False
+            clone_x = paddle.clone(x)
+
+            y = clone_x**3
+            y.backward()
+            print(clone_x.grad)          # [3]
+            print(x.grad)                # [3]
+    """
+    return x.clone()
+
+
 #NOTE(zhiqiu): not public 
 def _memcpy(input, place=None, output=None):
     """