[fp16] fix fp16 support for nn.PairwiseDistance (#50849)

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

@@ -286,6 +286,97 @@ class TestPairwiseDistance(unittest.TestCase):
             dygraph_functional_ret, excepted_value, rtol=1e-05
         )
 
+    def test_pairwise_distance_fp16(self):
+        epsilon = 1e-6
+        all_shape = [[5], [100, 100]]
+        dtypes = ['float16']
+        p_list = [-1, 0, 1, 2, np.inf, -np.inf]
+        places = [paddle.CPUPlace()]
+        if paddle.device.is_compiled_with_cuda():
+            places.append(paddle.CUDAPlace(0))
+        keeps = [False, True]
+        for place in places:
+            for shape in all_shape:
+                for dtype in dtypes:
+                    for p in p_list:
+                        for keepdim in keeps:
+                            x_np = np.random.random(shape).astype(dtype)
+                            y_np = np.random.random(shape).astype(dtype)
+                            # Currently, the CPU does not support float16
+                            if dtype == "float16" and isinstance(
+                                place, paddle.CPUPlace
+                            ):
+                                continue
+                            static_ret = test_static(
+                                place,
+                                x_np,
+                                y_np,
+                                p,
+                                epsilon=epsilon,
+                                keepdim=keepdim,
+                            )
+                            dygraph_ret = test_dygraph(
+                                place,
+                                x_np,
+                                y_np,
+                                p,
+                                epsilon=epsilon,
+                                keepdim=keepdim,
+                            )
+                            excepted_value = np_pairwise_distance(
+                                x_np, y_np, p, epsilon=epsilon, keepdim=keepdim
+                            )
+
+                            self.assertEqual(
+                                static_ret.shape, excepted_value.shape
+                            )
+                            self.assertEqual(
+                                dygraph_ret.shape, excepted_value.shape
+                            )
+
+                            np.testing.assert_allclose(
+                                static_ret, excepted_value, atol=1e-03
+                            )
+                            np.testing.assert_allclose(
+                                dygraph_ret, excepted_value, atol=1e-03
+                            )
+                            static_functional_ret = test_static(
+                                place,
+                                x_np,
+                                y_np,
+                                p,
+                                epsilon=epsilon,
+                                keepdim=keepdim,
+                            )
+                            dygraph_functional_ret = test_dygraph(
+                                place,
+                                x_np,
+                                y_np,
+                                p,
+                                epsilon=epsilon,
+                                keepdim=keepdim,
+                            )
+
+                            self.assertEqual(
+                                static_functional_ret.shape,
+                                excepted_value.shape,
+                            )
+                            self.assertEqual(
+                                dygraph_functional_ret.shape,
+                                excepted_value.shape,
+                            )
+
+                            np.testing.assert_allclose(
+                                static_functional_ret,
+                                excepted_value,
+                                atol=1e-03,
+                            )
+                            np.testing.assert_allclose(
+                                dygraph_functional_ret,
+                                excepted_value,
+                                atol=1e-03,
+                            )
+
 
 if __name__ == "__main__":
     unittest.main()

python/paddle/nn/functional/distance.py

@@ -35,10 +35,10 @@ def pairwise_distance(x, y, p=2.0, epsilon=1e-6, keepdim=False, name=None):
     Parameters:
         x (Tensor): Tensor, shape is :math:`[N, D]` or :math:`[D]`, where :math:`N`
             is batch size, :math:`D` is the dimension of vector. Available dtype is
-            float32, float64.
+            float16, float32, float64.
         y (Tensor): Tensor, shape is :math:`[N, D]` or :math:`[D]`, where :math:`N`
             is batch size, :math:`D` is the dimension of vector. Available dtype is
-            float32, float64.
+            float16, float32, float64.
         p (float, optional): The order of norm. Default: :math:`2.0`.
         epsilon (float, optional): Add small value to avoid division by zero.
             Default: :math:`1e-6`.
@@ -84,10 +84,10 @@ def pairwise_distance(x, y, p=2.0, epsilon=1e-6, keepdim=False, name=None):
         check_type(keepdim, 'keepdim', (bool), 'PairwiseDistance')
 
         check_variable_and_dtype(
-            x, 'x', ['float32', 'float64'], 'PairwiseDistance'
+            x, 'x', ['float16', 'float32', 'float64'], 'PairwiseDistance'
         )
         check_variable_and_dtype(
-            y, 'y', ['float32', 'float64'], 'PairwiseDistance'
+            y, 'y', ['float16', 'float32', 'float64'], 'PairwiseDistance'
         )
         sub = paddle.subtract(x, y)
         if epsilon != 0.0:

python/paddle/nn/layer/distance.py

@@ -40,7 +40,7 @@ class PairwiseDistance(Layer):
 
     Shape:
         - x: :math:`[N, D]` or :math:`[D]`, where :math:`N` is batch size, :math:`D`
-          is the dimension of the data. Available data type is float32, float64.
+          is the dimension of the data. Available data type is float16, float32, float64.
         - y: :math:`[N, D]` or :math:`[D]`, y have the same dtype as x.
         - output: The same dtype as input tensor.
             - If :attr:`keepdim` is True, the output shape is :math:`[N, 1]` or :math:`[1]`,