add sigmoid composite rule (#50827)

* add sigmoid composite rule

* add python api

* fix code style.

* add check_prim=True

* add sigmoid fp16 unit test.

* fix code style.

* rm bf16 check_prim

* fix code style.

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

@@ -259,6 +259,9 @@ class TestParameter:
 class TestSigmoid(TestActivation):
     def setUp(self):
         self.op_type = "sigmoid"
+        self.prim_op_type = "comp"
+        self.enable_cinn = False
+        self.python_api = paddle.nn.functional.sigmoid
         self.init_dtype()
         self.init_shape()
 
@@ -275,7 +278,7 @@ class TestSigmoid(TestActivation):
     def test_check_grad(self):
         if self.dtype == np.float16:
             return
-        self.check_grad(['X'], 'Out', max_relative_error=0.01)
+        self.check_grad(['X'], 'Out', max_relative_error=0.01, check_prim=True)
 
 
 class TestSigmoid_ZeroDim(TestSigmoid):
@@ -283,12 +286,45 @@ class TestSigmoid_ZeroDim(TestSigmoid):
         self.shape = []
 
 
+class TestSigmoidFP16(TestActivation):
+    def setUp(self):
+        self.op_type = "sigmoid"
+        self.prim_op_type = "comp"
+        self.enable_cinn = False
+        self.only_prim = True
+        self.python_api = paddle.nn.functional.sigmoid
+        self.init_dtype()
+        self.init_shape()
+
+        np.random.seed(1024)
+        x = np.random.uniform(-1, 1, self.shape).astype(self.dtype)
+        out = 1 / (1 + np.exp(-x))
+
+        self.inputs = {'X': OpTest.np_dtype_to_fluid_dtype(x)}
+        self.outputs = {'Out': out}
+
+    def init_dtype(self):
+        self.dtype = np.float16
+
+    def test_check_grad(self):
+        self.check_grad(['X'], 'Out', max_relative_error=0.01, check_prim=True)
+
+    def test_check_output(self):
+        check_eager = False
+        if hasattr(self, 'check_eager'):
+            check_eager = self.check_eager
+        self.check_output(check_eager=check_eager, check_prim=True)
+
+
 @unittest.skipIf(
     not core.is_compiled_with_cuda(), "core is not compiled with CUDA"
 )
 class TestSigmoidBF16(OpTest):
     def setUp(self):
         self.op_type = "sigmoid"
+        self.prim_op_type = "comp"
+        self.enable_cinn = False
+        self.python_api = paddle.nn.functional.sigmoid
         self.init_dtype()
         self.init_shape()
 
@@ -309,6 +345,7 @@ class TestSigmoidBF16(OpTest):
 
     def test_check_output(self):
         place = core.CUDAPlace(0)
+        # elementwise_pow can not support bfloat16, skip check_prim = True.
         self.check_output_with_place(place)
 
     def test_check_grad(self):
@@ -3733,6 +3770,7 @@ def create_test_act_fp16_class(
 create_test_act_fp16_class(TestActivation)
 create_test_act_fp16_class(TestExpm1)
 create_test_act_fp16_class(TestSigmoid)
+create_test_act_fp16_class(TestSigmoidFP16)
 create_test_act_fp16_class(TestSilu)
 create_test_act_fp16_class(TestSiluFP16)
 create_test_act_fp16_class(TestLogSigmoid)

python/paddle/incubate/autograd/composite_rules.py

@@ -286,6 +286,17 @@ def hard_swish_composite(x):
     return res
 
 
+@REGISTER_COMPOSITE('sigmoid')
+def sigmoid_composite(x):
+    """
+    define composite rule of op sigmoid
+    res = 1 / (1 + exp(-x))
+    """
+    sum_temp = 1 + exp(-x)
+    res = 1 / sum_temp
+    return res
+
+
 @REGISTER_COMPOSITE('silu')
 def silu_composite(x):
     """

python/paddle/tensor/ops.py

@@ -569,6 +569,7 @@ def exp(x, name=None):
                 'float64',
                 'complex64',
                 'complex128',
+                'uint16',
             ],
             'exp',
         )
@@ -808,7 +809,7 @@ def sigmoid(x, name=None):
         return _C_ops.sigmoid(x)
     else:
         check_variable_and_dtype(
-            x, 'x', ['float16', 'float32', 'float64'], 'sigmoid'
+            x, 'x', ['float16', 'float32', 'float64', 'uint16'], 'sigmoid'
         )
         helper = LayerHelper('sigmoid', **locals())
         out = helper.create_variable_for_type_inference(dtype=x.dtype)