[cherry-pick]fix reshape input(x) error check on float16. test=release/1.6 (#20529) (#20551)

python/paddle/fluid/layers/nn.py

@@ -8585,9 +8585,15 @@ def reshape(x, shape, actual_shape=None, act=None, inplace=False, name=None):
             "The type of 'x' in reshape must be Variable, but received %s." %
             (type(x)))
 
-    if convert_dtype(x.dtype) not in ['float32', 'float64', 'int32', 'int64']:
+    if convert_dtype(x.dtype) in ['float16']:
+        warnings.warn(
+            "The data type of 'x' in reshape only support float16 in GPU now.")
+
+    if convert_dtype(x.dtype) not in [
+            'float16', 'float32', 'float64', 'int32', 'int64'
+    ]:
         raise TypeError(
-            "The data type of 'x' in reshape must be float32, float64, int32 or int64, "
+            "The data type of 'x' in reshape must be float16, float32, float64, int32 or int64, "
             "but received %s." % (convert_dtype(x.dtype)))
 
     if not isinstance(shape, (list, tuple, Variable)):

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

@@ -238,17 +238,27 @@ class TestReshapeOpError(OpTest):
 
             self.assertRaises(TypeError, test_x_type)
 
-            # The x dtype of reshape_op must be float32, float64, int32 or int64.
+            # The x dtype of reshape_op must be float16, float32, float64, int32 or int64.
             def test_x_dtype():
                 x2 = fluid.layers.data(
                     name="x2",
                     shape=[2, 25],
                     append_batch_size=False,
-                    dtype="float16")
+                    dtype="bool")
                 fluid.layers.reshape(x2, shape=[2, 5, 5])
 
             self.assertRaises(TypeError, test_x_dtype)
 
+            def test_x_dtype_float16():
+                x_float16 = fluid.layers.data(
+                    name="x_float16",
+                    shape=[2, 25],
+                    append_batch_size=False,
+                    dtype="float16")
+                fluid.layers.reshape(x_float16, shape=[2, 5, 5])
+
+            test_x_dtype_float16()
+
             x3 = fluid.layers.data(
                 name="x3",
                 shape=[2, 25],