add set default dtype, get default dtype (#26006)

* add set/get default dtype

python/paddle/__init__.py

@@ -225,6 +225,8 @@ from .framework import ExponentialDecay  #DEFINE_ALIAS
 from .framework import InverseTimeDecay  #DEFINE_ALIAS
 from .framework import PolynomialDecay  #DEFINE_ALIAS
 from .framework import CosineDecay  #DEFINE_ALIAS
+from .framework import set_default_dtype  #DEFINE_ALIAS
+from .framework import get_default_dtype  #DEFINE_ALIAS
 
 from .tensor.search import index_sample  #DEFINE_ALIAS
 from .tensor.stat import mean  #DEFINE_ALIAS

python/paddle/fluid/dygraph/layers.py

@@ -283,7 +283,7 @@ class Layer(core.Layer):
     def create_parameter(self,
                          shape,
                          attr=None,
-                         dtype='float32',
+                         dtype=None,
                          is_bias=False,
                          default_initializer=None):
         """Create parameters for this layer.

python/paddle/fluid/layer_helper_base.py

@@ -23,8 +23,13 @@ from .param_attr import ParamAttr, WeightNormParamAttr
 from . import core
 from .initializer import _global_weight_initializer, _global_bias_initializer
 
+__all__ = ['LayerHelperBase']
+
 
 class LayerHelperBase(object):
+    # global dtype
+    __dtype = "float32"
+
     def __init__(self, name, layer_type):
         self._layer_type = layer_type
         self._name = name
@@ -45,6 +50,14 @@ class LayerHelperBase(object):
     def startup_program(self):
         return default_startup_program()
 
+    @classmethod
+    def set_default_dtype(cls, dtype):
+        cls.__dtype = dtype
+
+    @classmethod
+    def get_default_dtype(cls):
+        return cls.__dtype
+
     def to_variable(self, value, name=None):
         """
         The API will create a ``Variable`` object from numpy\.ndarray or Variable object.
@@ -277,7 +290,7 @@ class LayerHelperBase(object):
     def create_parameter(self,
                          attr,
                          shape,
-                         dtype,
+                         dtype=None,
                          is_bias=False,
                          default_initializer=None,
                          stop_gradient=False,
@@ -299,6 +312,9 @@ class LayerHelperBase(object):
         if not attr:
             return None
         assert isinstance(attr, ParamAttr)
+        # set global dtype
+        if not dtype:
+            dtype = self.__dtype
         if is_bias:
             suffix = 'b'
             default_initializer = _global_bias_initializer(
@@ -372,6 +388,9 @@ class LayerHelperBase(object):
             based on operator's `VarTypeInference` implementation in
             infer_var_type.
         """
+        # set global dtype
+        if not dtype:
+            dtype = self.__dtype
         return self.main_program.current_block().create_var(
             name=unique_name.generate_with_ignorable_key(".".join(
                 [self.name, 'tmp'])),

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

@@ -0,0 +1,41 @@
+#  Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# 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 __future__ import print_function
+import unittest
+import numpy as np
+from paddle.framework import set_default_dtype, get_default_dtype
+import paddle
+import paddle.fluid as fluid
+from paddle.fluid.dygraph import Linear
+import paddle.fluid.core as core
+from paddle import to_variable
+
+
+class TestDefaultType(unittest.TestCase):
+    def check_default(self):
+        self.assertEqual("float32", get_default_dtype())
+
+    def test_api(self):
+        self.check_default()
+
+        set_default_dtype("float64")
+        self.assertEqual("float64", get_default_dtype())
+
+        set_default_dtype(np.int32)
+        self.assertEqual("int32", get_default_dtype())
+
+
+if __name__ == '__main__':
+    unittest.main()

python/paddle/framework/__init__.py

@@ -15,7 +15,8 @@
 # TODO: import framework api under this directory 
 __all__ = [
     'create_global_var', 'create_parameter', 'ParamAttr', 'Variable',
-    'CPUPlace', 'CUDAPlace', 'CUDAPinnedPlace'
+    'CPUPlace', 'CUDAPlace', 'CUDAPinnedPlace', 'get_default_dtype',
+    'set_default_dtype'
 ]
 
 __all__ += [
@@ -30,6 +31,8 @@ __all__ += [
 
 from . import random
 from .random import manual_seed
+from .framework import get_default_dtype
+from .framework import set_default_dtype
 
 from ..fluid.framework import Variable  #DEFINE_ALIAS
 from ..fluid.framework import ComplexVariable  #DEFINE_ALIAS

python/paddle/framework/framework.py

@@ -13,5 +13,46 @@
 # limitations under the License.
 
 # TODO: define framework api 
-# __all__ = ['set_default_dtype',
-#            'get_default_dtype']
+from paddle.fluid.layer_helper_base import LayerHelperBase
+from paddle.fluid.data_feeder import convert_dtype
+
+__all__ = ['set_default_dtype', 'get_default_dtype']
+
+
+def set_default_dtype(d):
+    """
+    Set default dtype. The default dtype is initially float32
+
+    Args:
+        d(string|np.dtype): the dtype to make the default
+
+    Returns:
+        None.
+
+    Examples:
+        .. code-block:: python
+
+            import paddle
+            paddle.set_default_dtype("float32")
+
+    """
+    d = convert_dtype(d)
+    LayerHelperBase.set_default_dtype(d)
+
+
+def get_default_dtype():
+    """
+    Get the current default dtype. The default dtype is initially float32
+
+    Args:
+        None.
+    Returns:
+        The default dtype.
+
+    Examples:
+        .. code-block:: python
+
+            import paddle
+            paddle.get_default_dtype()
+    """
+    return LayerHelperBase.get_default_dtype()