[AMP OP&Test] add unittest for log_softmax (#52264)

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

@@ -102,6 +102,29 @@ class TestLogSoftmaxAxis(TestLogSoftmaxOp):
         self.axis = 1
 
 
+class TestLogSoftmaxFP16OP(TestLogSoftmaxOp):
+    def set_attrs(self):
+        self.dtype = np.float16
+
+    def test_check_output(self):
+        self.check_output(atol=1e-3)
+
+    def test_check_grad(self):
+        self.check_grad(['X'], ['Out'], max_relative_error=1e-2)
+
+
+class TestLogSoftmaxShapeFP16OP(TestLogSoftmaxFP16OP):
+    def set_attrs(self):
+        self.dtype = np.float16
+        self.shape = [12, 10]
+
+
+class TestLogSoftmaxAxisFP16OP(TestLogSoftmaxFP16OP):
+    def set_attrs(self):
+        self.dtype = np.float16
+        self.axis = 1
+
+
 @unittest.skipIf(
     not core.is_compiled_with_cuda(), "core is not compiled with CUDA"
 )