update mul_op input data type check test=develop (#20552)

python/paddle/fluid/layers/nn.py

@@ -14729,13 +14729,19 @@ def mul(x, y, x_num_col_dims=1, y_num_col_dims=1, name=None):
         raise TypeError(
             "The type of 'y' in mul must be Variable, but received %s" %
             (type(y)))
-    if convert_dtype(x.dtype) not in ['float32', 'float64']:
+    if convert_dtype(x.dtype) in ['float16']:
+        warnings.warn(
+            "The data type of 'x' in mul only support float16 in GPU now.")
+    if convert_dtype(y.dtype) in ['float16']:
+        warnings.warn(
+            "The data type of 'y' in mul only support float16 in GPU now.")
+    if convert_dtype(x.dtype) not in ['float16', 'float32', 'float64']:
         raise TypeError(
-            "The data type of 'x' in mul must be float32 or float64, but received %s."
+            "The data type of 'x' in mul must be float16, float32 or float64, but received %s."
             % (convert_dtype(x.dtype)))
-    if convert_dtype(y.dtype) not in ['float32', 'float64']:
+    if convert_dtype(y.dtype) not in ['float16', 'float32', 'float64']:
         raise TypeError(
-            "The data type of 'y' in softmax must be float32 or float64, but received %s."
+            "The data type of 'y' in mul must be float16, float32 or float64, but received %s."
             % (convert_dtype(y.dtype)))
 
     if name is None: