support fp16 on AlphaDropout (#50917)

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

@@ -980,6 +980,30 @@ class TestAlphaDropoutCAPI(unittest.TestCase):
                     result.numpy(), result_np, rtol=1e-05
                 )
 
+    def test_static_fp16_gpu(self):
+        if paddle.fluid.core.is_compiled_with_cuda():
+            place = paddle.CUDAPlace(0)
+            with paddle.static.program_guard(
+                paddle.static.Program(), paddle.static.Program()
+            ):
+                input = np.random.random([2, 3]).astype("float16")
+
+                x = paddle.static.data(name="x", shape=[2, 3], dtype="float16")
+
+                m = paddle.nn.AlphaDropout(p=0.0)
+                y = m(x)
+
+                exe = paddle.static.Executor(place)
+                res = exe.run(
+                    paddle.static.default_main_program(),
+                    feed={
+                        "x": input,
+                    },
+                    fetch_list=[y],
+                )
+
+                np.testing.assert_allclose(res[0], input, rtol=1e-05)
+
 
 class TestDropoutWithDeterminateSeedGenerator(unittest.TestCase):
     def setUp(self):

python/paddle/nn/functional/common.py

@@ -1384,7 +1384,7 @@ def alpha_dropout(x, p=0.5, training=True, name=None):
     Alpha Dropout fits well to SELU activate function by randomly setting activations to the negative saturation value.
 
     Args:
-        x (Tensor): The input tensor. The data type is float32 or float64.
+        x (Tensor): The input tensor. The data type is float16, float32 or float64.
         p (float | int): Probability of setting units to zero. Default 0.5.
         training (bool): A flag indicating whether it is in train phrase or not. Default True.
         name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
@@ -1416,7 +1416,7 @@ def alpha_dropout(x, p=0.5, training=True, name=None):
 
     if not in_dynamic_mode():
         check_variable_and_dtype(
-            x, 'x', ['float32', 'float64'], 'alpha_dropout'
+            x, 'x', ['float16', 'float32', 'float64'], 'alpha_dropout'
         )
 
     if training: