fix default create_parameter dtype maching initializers (#15521)

* fix default create_parameter dtype maching initializers test=develop

* update type check test=develop

* update test=develop

python/paddle/fluid/layer_helper.py

@@ -300,6 +300,17 @@ class LayerHelper(object):
             attr.name = unique_name.generate(".".join([self.name, suffix]))
 
         if default_initializer is None and attr.initializer is None:
+            if isinstance(dtype, core.VarDesc.VarType):
+                if dtype != core.VarDesc.VarType.FP32 and \
+                    dtype != core.VarDesc.VarType.FP64:
+                    raise TypeError(
+                        "Can not create parameter with default initializer when dtype is not float type. Set default_initializer to fit the parameter dtype!"
+                    )
+            else:
+                if not (dtype.startswith("float") or dtype == "double"):
+                    raise TypeError(
+                        "Can not create parameter with default initializer when dtype is not float type. Set default_initializer to fit the parameter dtype!"
+                    )
             if is_bias:
                 attr._set_default_bias_initializer()
             else:

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

@@ -58,7 +58,8 @@ class TestBook(unittest.TestCase):
     def test_simple_conv2d(self):
         program = Program()
         with program_guard(program, startup_program=Program()):
-            images = layers.data(name='pixel', shape=[3, 48, 48], dtype='int32')
+            images = layers.data(
+                name='pixel', shape=[3, 48, 48], dtype='float32')
             layers.conv2d(input=images, num_filters=3, filter_size=[4, 4])
 
         print(str(program))