Fix bug in test_prelu and test_xe

They were using float64 for FP32 kernel before.

python/paddle/v2/framework/tests/test_cross_entropy_op.py

@@ -80,7 +80,7 @@ class TestCrossEntropyOp3(OpTest):
         cross_entropy2 = (-label * np.log(X)).sum(
             axis=1, keepdims=True).astype("float32")
 
-        self.inputs = {"X": X, "Label": label}
+        self.inputs = {"X": X, "Label": label.astype(np.float32)}
         self.outputs = {"Y": cross_entropy}
         self.attrs = {"softLabel": True}
 

python/paddle/v2/framework/tests/test_prelu_op.py

@@ -17,7 +17,7 @@ class PReluTest(OpTest):
 
         x_np_sign = np.sign(x_np)
         x_np = x_np_sign * np.maximum(x_np, .005)
-        alpha_np = np.array([.1])
+        alpha_np = np.array([.1], dtype="float32")
         self.inputs = {'X': x_np, 'Alpha': alpha_np}
         out_np = np.maximum(self.inputs['X'], 0.)
         out_np = out_np + np.minimum(self.inputs['X'],